Programs & Examples On #Android

Android is Google's mobile operating system, used for programming or developing digital devices (Smartphones, Tablets, Automobiles, TVs, Wear, Glass, IoT). For topics related to Android, use Android-specific tags such as android-intent, not intent, android-activity, not activity, android-adapter, not adapter etc. For questions other than development or programming, but related to Android framework, use the link: https://android.stackexchange.com.

open failed: EACCES (Permission denied)

I ran into a similar issue a while back.

Your problem could be in two different areas. It's either how you're creating the file to write to, or your method of writing could be flawed in that it is phone dependent.

If you're writing the file to a specific location on the SD card, try using Environment variables. They should always point to a valid location. Here's an example to write to the downloads folder:

java.io.File xmlFile = new java.io.File(Environment
    .getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
     + "/Filename.xml");

If you're writing the file to the application's internal storage. Try this example:

java.io.File xmlFile = new java.io.File((getActivity()
   .getApplicationContext().getFileStreamPath("FileName.xml")
   .getPath()));

Personally I rely on external libraries to handle the streaming to file. This one hasn't failed me yet.

org.apache.commons.io.FileUtils.copyInputStreamToFile(is, file);

I've lost data one too many times on a failed write command, so I rely on well-known and tested libraries for my IO heavy lifting.

If the files are large, you may also want to look into running the IO in the background, or use callbacks.

If you're already using environment variables, it could be a permissions issue. Check out Justin Fiedler's answer below.

Get Path from another app (WhatsApp)

Using the code example below will return to you the bitmap :

BitmapFactory.decodeStream(getContentResolver().openInputStream(Uri.parse("content://com.whatsapp.provider.media/item/128752")))

After that you all know what you have to do.

Start new Activity and finish current one in Android?

Use finish like this:

Intent i = new Intent(Main_Menu.this, NextActivity.class);
finish();  //Kill the activity from which you will go to next activity 
startActivity(i);

FLAG_ACTIVITY_NO_HISTORY you can use in case for the activity you want to finish. For exampe you are going from A-->B--C. You want to finish activity B when you go from B-->C so when you go from A-->B you can use this flag. When you go to some other activity this activity will be automatically finished.

To learn more on using Intent.FLAG_ACTIVITY_NO_HISTORY read: http://developer.android.com/reference/android/content/Intent.html#FLAG_ACTIVITY_NO_HISTORY

How to get text from EditText?

Put this in your MainActivity:

{
    public EditText bizname, storeno, rcpt, item, price, tax, total;
    public Button click, click2;
    int contentView;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.main_activity );
        bizname = (EditText) findViewById( R.id.editBizName );
        item = (EditText) findViewById( R.id.editItem );
        price = (EditText) findViewById( R.id.editPrice );
        tax = (EditText) findViewById( R.id.editTax );
        total = (EditText) findViewById( R.id.editTotal );
        click = (Button) findViewById( R.id.button );
    }
}

Put this under a button or something

public void clickBusiness(View view) {
    checkPermsOfStorage( this );

    bizname = (EditText) findViewById( R.id.editBizName );
    item = (EditText) findViewById( R.id.editItem );
    price = (EditText) findViewById( R.id.editPrice );
    tax = (EditText) findViewById( R.id.editTax );
    total = (EditText) findViewById( R.id.editTotal );
    String x = ("\nItem/Price: " + item.getText() + price.getText() + "\nTax/Total" + tax.getText() + total.getText());
    Toast.makeText( this, x, Toast.LENGTH_SHORT ).show();
    try {
        this.WriteBusiness(bizname,storeno,rcpt,item,price,tax,total);
        String vv = tax.getText().toString();
        System.console().printf( "%s", vv );
        //new XMLDivisionWriter(getString(R.string.SDDoc) + "/tax_div_business.xml");
    } catch (ReflectiveOperationException e) {
        e.printStackTrace();
    }
}

There! The debate is settled!

libz.so.1: cannot open shared object file

This worked for me

sudo apt-get install libc6-i386 lib32stdc++6 lib32gcc1 lib32ncurses5

Error:(9, 5) error: resource android:attr/dialogCornerRadius not found

 buildscript {

    project.ext {
        supportLibVersion = '27.1.1'
        compileVersion = 28
        minSupportedVersion = 22
    }
}

and set dependencies:

implementation "com.android.support:appcompat-v7:$project.supportLibVersion"

Show only two digit after decimal

Many other answers only do formatting. This approach will return value instead of only print format.

double number1 = 10.123456;
double number2 = (int)(Math.round(number1 * 100))/100.0;
System.out.println(number2);

Send a SMS via intent

If you want a certain message, use this:

String phoneNo = "";//The phone number you want to text
String sms= "";//The message you want to text to the phone

Intent smsIntent = new Intent(Intent.ACTION_VIEW, Uri.fromParts("sms", phoneNo, null));
smsIntent.putExtra("sms_body",sms);
startActivity(smsIntent);

SQLite Query in Android to count rows

int nombr = 0;
Cursor cursor = sqlDatabase.rawQuery("SELECT column FROM table WHERE column = Value", null);
nombr = cursor.getCount();

findViewByID returns null

Set the activity content from a layout resource. ie.,setContentView(R.layout.basicXml);

iOS / Android cross platform development

My experience with making something very simple in PhoneGap+jQuery Mobile was fine. I was able to do it quickly for iOS. However, it didn't work on my Android phones without making some changes. The project was a very simple app to take pictures and post them to a web site. And at the end of the day it felt "clunky" compared to a true native app.

I don't believe there will ever be easy cross platform development. I think the browser is as close as you will get. By choosing something like PhoneGap I think you are just trading one set of pain points for a different set of pain points.

Check if a given time lies between two times regardless of date

/**
 * @param initialTime - in format HH:mm:ss
 * @param finalTime   - in format HH:mm:ss
 * @param timeToCheck - in format HH:mm:ss
 * @return initialTime <= timeToCheck < finalTime
 * @throws IllegalArgumentException if passed date with wrong format
 */
public static boolean isTimeBetweenTwoTime(String initialTime, String finalTime, String timeToCheck) throws IllegalArgumentException {
    String reg = "^([0-1][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9])$";
    if (initialTime.matches(reg) && finalTime.matches(reg) && timeToCheck.matches(reg)) {
        SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss", Locale.getDefault());
        Date inTime = parseDate(dateFormat, initialTime);
        Date finTime = parseDate(dateFormat, finalTime);
        Date checkedTime = parseDate(dateFormat, timeToCheck);

        if (finalTime.compareTo(initialTime) < 0) {
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(finTime);
            calendar.add(Calendar.DAY_OF_YEAR, 1);
            finTime = calendar.getTime();
            if (timeToCheck.compareTo(initialTime) < 0) {
                calendar.setTime(checkedTime);
                calendar.add(Calendar.DAY_OF_YEAR, 1);
                checkedTime = calendar.getTime();
            }
        }

        return (checkedTime.after(inTime) || checkedTime.compareTo(inTime) == 0) && checkedTime.before(finTime);
    } else {
        throw new IllegalArgumentException("Not a valid time, expecting HH:MM:SS format");
    }
}

/**
 * @param initialTime - in format HH:mm:ss
 * @param finalTime   - in format HH:mm:ss
 * @return initialTime <= now < finalTime
 * @throws IllegalArgumentException if passed date with wrong format
 */
public static boolean isNowBetweenTwoTime(String initialTime, String finalTime) throws IllegalArgumentException {
    return isTimeBetweenTwoTime(initialTime, finalTime,
            String.valueOf(DateFormat.format("HH:mm:ss", new Date()))
    );
}

private static Date parseDate(SimpleDateFormat dateFormat, String data) {
    try {
        return dateFormat.parse(data);
    } catch (ParseException e) {
        throw new IllegalArgumentException("Not a valid time");
    }
}

"Failed to install the following Android SDK packages as some licences have not been accepted" error

in my case I just installed a new version of android studio on a new laptop and cloned the old repository where buildToolsVersion "30.0.2" at application level build.gradle. I just upgraded to 30.0.3 which android studio recommended on its own and the problem went away

Send Email Intent

There is an easy solution also with ACTION_VIEW:

  Intent intent = new Intent(Intent.ACTION_VIEW);
        Uri data = Uri.parse("mailto:[email protected]?subject=Feedback");
        intent.setData(data);
        startActivity(intent);

Disabling of EditText in Android

Use this to disable user input

android:focusable="false"

android:editable="false" This method is deprecated one.

Which Android IDE is better - Android Studio or Eclipse?

The use of IDE is your personal preference. But personally if I had to choose, Eclipse is a widely known, trusted and certainly offers more features then Android Studio. Android Studio is a little new right now. May be it's upcoming versions keep up to Eclipse level soon.

R cannot be resolved - Android error

It worked for me with Right Click>Android Tools>Fix project properties and some time aftr restarting Eclipse.

How do I solve the INSTALL_FAILED_DEXOPT error?

I had this error testing on a real device. Clearing cache/uninstalling, restarting everything didn't work for me, deleting the contents of the build folder did :) (Android studio)

Scrollview vertical and horizontal in android

Try this

<?xml version="1.0" encoding="utf-8"?>
<ScrollView android:id="@+id/Sview" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"
        xmlns:android="http://schemas.android.com/apk/res/android">
<HorizontalScrollView 
   android:id="@+id/hview" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content">
<ImageView .......
 [here xml code for image]
</ImageView>
</HorizontalScrollView>
</ScrollView>

How to change package name of Android Project in Eclipse?

I had big trouble with this too.

I renamed the project and the package via refactoring, but it rendered the app useless. I renamed it back to the original and used the Android tools to rename the package and this worked, but my package folder and classes had the old name.

I then refactored the package folder. Now the app wouldn't run. My manifest was a mess. It doubled up my launcher name for example, com.ronguilmet.app/com.ronguilmet.com.class. I fixed that, and I had to manually edit all activities.

Android: How to stretch an image to the screen width while maintaining aspect ratio?

Setting adjustViewBounds to true and using a LinearLayout view group worked very well for me. No need to subclass or ask for device metrics:

//NOTE: "this" is a subclass of LinearLayout
ImageView splashImageView = new ImageView(context);
splashImageView.setImageResource(R.drawable.splash);
splashImageView.setAdjustViewBounds(true);
addView(splashImageView);

Android RatingBar change star colors

Now you can use DrawableCompat from AppCompat v22.1.0 onwards to dynamically tint all kind of drawables, useful when you're supporting multiple themes with a single set of drawables. For example:

LayerDrawable layerDrawable = (LayerDrawable) ratingBar.getProgressDrawable();
DrawableCompat.setTint(DrawableCompat.wrap(layerDrawable.getDrawable(0)), Color.RED);   // Empty star
DrawableCompat.setTint(DrawableCompat.wrap(layerDrawable.getDrawable(1)), Color.GREEN); // Partial star
DrawableCompat.setTint(DrawableCompat.wrap(layerDrawable.getDrawable(2)), Color.BLUE);  // Full star

This is backwards compatible down to API 4. Also see Chris Banes' blog post on Support Libraries v22.1.0

For the actual size and shape you will need to define a new style and layer-list drawables for the appropriate size, as others have already answered above.

Fully change package name including company domain

I have not changed any package name. The following two steps worked for me. After doing the following, the application was installed as a NEW one , eventhough there was two applications with the same package name.

1) In the build.gradle

applicationId "mynew.mynewpackage.com"

2) In the AndroidManifest.xml android:authorities="mynew.mynewpackage.com.fileprovider"

Difference between onStart() and onResume()

onStart() means Activity entered into visible state and layout is created but can't interact with this activity layout.

Resume() means now you can do interaction with activity layout.

How to split the screen with two equal LinearLayouts?

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <LinearLayout
            android:orientation="vertical"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            tools:context=".MainActivity">
            <TextView
                android:layout_marginTop="16dp"
                android:textSize="18sp"
                android:textStyle="bold"
                android:padding="4dp"
                android:textColor="#EA80FC"
                android:fontFamily="sans-serif-medium"
                android:text="@string/team_a"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <TextView
                android:id="@+id/team_a_score"
                android:text="@string/_0"
                android:textSize="56sp"
                android:padding="4dp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <TextView
                android:id="@+id/team_a_fouls"
                android:text="@string/fouls"
                android:padding="4dp"
                android:textSize="26sp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_1_points"
                android:layout_width="match_parent"
                android:onClick="addOnePointTeamA"
                android:textColor="#fff"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_2_points"
                android:textColor="#fff"
                android:onClick="addTwoPointTeamA"
                android:layout_width="match_parent"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_3_points"
                android:textColor="#fff"
                android:onClick="addThreePointTeamA"
                android:layout_margin="6dp"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_1_point_foul"
                android:textColor="#fff"
                android:layout_width="match_parent"
                android:onClick="addOnePointFoulTeamA"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />
        </LinearLayout>
        <LinearLayout
            android:orientation="vertical"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            tools:context=".MainActivity">
            <TextView
                android:text="@string/team_b"
                android:textColor="#EA80FC"
                android:textStyle="bold"
                android:padding="4dp"
                android:layout_marginTop="16dp"
                android:fontFamily="sans-serif-medium"
                android:textSize="18sp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <TextView
                android:id="@+id/team_b_score"
                android:text="0"
                android:padding="4dp"
                android:textSize="56sp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <TextView
                android:id="@+id/team_b_fouls"
                android:text="Fouls"
                android:padding="4dp"
                android:textSize="26sp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_1_points"
                android:textColor="#fff"
                android:fontFamily="sans-serif-medium"
                android:layout_width="match_parent"
                android:onClick="addOnePointTeamB"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_2_points"
                android:layout_margin="6dp"
                android:fontFamily="sans-serif-medium"
                android:textColor="#fff"
                android:onClick="addTwoPointTeamB"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_3_points"
                android:fontFamily="sans-serif-medium"
                android:textColor="#fff"
                android:onClick="addThreePointTeamB"
                android:layout_margin="6dp"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_1_point_foul"
                android:textColor="#fff"
                android:onClick="addOnePointFoulTeamB"
                android:layout_width="match_parent"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />


        </LinearLayout>
    </LinearLayout>
    <Button
        android:text="@string/reset"
        android:layout_marginBottom="25dp"
        android:onClick="resetScore"
        android:textColor="#fff"
        android:fontFamily="sans-serif-medium"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</RelativeLayout>

add maven repository to build.gradle

Add the maven repository outside the buildscript configuration block of your main build.gradle file as follows:

repositories {
        maven {
            url "https://github.com/jitsi/jitsi-maven-repository/raw/master/releases"
        }
    }

Make sure that you add them after the following:

apply plugin: 'com.android.application'

Cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6

if you are in android project

in your app's build.gradle under android{}

android{
//other configs...
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = "1.8"
    }
}

Height of status bar in Android

Hardcoding the size or using reflection to get the value of status_bar_height is considered bad practice. Chris Banes talked about this in at the Droidcon New York. The recommended way of getting the status bar size is via the OnApplyWindowInsetsListener:

myView.setOnApplyWindowInsetsListener { view, insets -> {
  val statusBarSize = insets.systemWindowInsetTop
  return insets
}

This was added in API 20 and is also backported via ViewAppCompat.

How to disable EditText in Android

The XML editable property is deprecated since API LEVEL 15.

You should use now the inputType property with the value none. But there is a bug that makes this functionality useless.

Here you can follow the issue status.

How to make an Android device vibrate? with different frequency?

I use the following utils method:

public static final void vibratePhone(Context context, short vibrateMilliSeconds) {
    Vibrator vibrator = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE);
    vibrator.vibrate(vibrateMilliSeconds);
}

Add the following permission to the AndroidManifest file

<uses-permission android:name="android.permission.VIBRATE"/>

You can use overloaded methods in case if you wish to use different types of vibrations (patterns / indefinite) as suggested above.

Set the absolute position of a view

My code for Xamarin, I am using FrameLayout for this purpose and following is my code:

               List<object> content = new List<object>();

        object aWebView = new {ContentType="web",Width="300", Height = "300",X="10",Y="30",ContentUrl="http://www.google.com" };
        content.Add(aWebView);
        object aWebView2 = new { ContentType = "image", Width = "300", Height = "300", X = "20", Y = "40", ContentUrl = "https://www.nasa.gov/sites/default/files/styles/image_card_4x3_ratio/public/thumbnails/image/leisa_christmas_false_color.png?itok=Jxf0IlS4" };
        content.Add(aWebView2);
        FrameLayout myLayout = (FrameLayout)FindViewById(Resource.Id.frameLayout1);
        foreach (object item in content)
        {

            string contentType = item.GetType().GetProperty("ContentType").GetValue(item, null).ToString();
            FrameLayout.LayoutParams param = new FrameLayout.LayoutParams(Convert.ToInt32(item.GetType().GetProperty("Width").GetValue(item, null).ToString()), Convert.ToInt32(item.GetType().GetProperty("Height").GetValue(item, null).ToString()));
            param.LeftMargin = Convert.ToInt32(item.GetType().GetProperty("X").GetValue(item, null).ToString());
            param.TopMargin = Convert.ToInt32(item.GetType().GetProperty("Y").GetValue(item, null).ToString());

            switch (contentType) {
                case "web":{
                        WebView webview = new WebView(this);

                        //webview.hei;
                        myLayout.AddView(webview, param);
                        webview.SetWebViewClient(new WebViewClient());
                        webview.LoadUrl(item.GetType().GetProperty("ContentUrl").GetValue(item, null).ToString());

                        break;
                    }
                case "image":
                    {
                        ImageView imageview = new ImageView(this);

                        //webview.hei;
                        myLayout.AddView(imageview, param);
                        var imageBitmap =  GetImageBitmapFromUrl("https://www.nasa.gov/sites/default/files/styles/image_card_4x3_ratio/public/thumbnails/image/leisa_christmas_false_color.png?itok=Jxf0IlS4");
                        imageview.SetImageBitmap(imageBitmap);


                        break;
                    }

            }

        }

It was useful for me because I needed the property of view to overlap each other on basis of their appearance, e.g the views get stacked one above other.

How to make primary key as autoincrement for Room Persistence lib

Its unbelievable after so many answers, but I did it little differently in the end. I don't like primary key to be nullable, I want to have it as first argument and also want to insert without defining it and also it should not be var.

@Entity(tableName = "employments")
data class Employment(
    @PrimaryKey(autoGenerate = true) val id: Long,
    @ColumnInfo(name = "code") val code: String,
    @ColumnInfo(name = "title") val name: String
){
    constructor(code: String, name: String) : this(0, code, name)
}

POST Multipart Form Data using Retrofit 2.0 including image

Don't use multiple parameters in the function name just go with simple few args convention that will increase the readability of codes, for this you can do like -

// MultipartBody.Part.createFormData("partName", data)
Call<SomReponse> methodName(@Part MultiPartBody.Part part);
// RequestBody.create(MediaType.get("text/plain"), data)
Call<SomReponse> methodName(@Part(value = "partName") RequestBody part); 
/* for single use or you can use by Part name with Request body */

// add multiple list of part as abstraction |ease of readability|
Call<SomReponse> methodName(@Part List<MultiPartBody.Part> parts); 
Call<SomReponse> methodName(@PartMap Map<String, RequestBody> parts);
// this way you will save the abstraction of multiple parts.

There can be multiple exceptions that you may encounter while using Retrofit, all of the exceptions documented as code, have a walkthrough to retrofit2/RequestFactory.java. you can able to two functions parseParameterAnnotation and parseMethodAnnotation where you can able to exception thrown, please go through this, it will save your much of time than googling/stackoverflow

Show hide fragment in android

This worked for me

FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        if(tag.equalsIgnoreCase("dashboard")){

            DashboardFragment dashboardFragment = (DashboardFragment)
                    fragmentManager.findFragmentByTag("dashboard");
            if(dashboardFragment!=null) ft.show(dashboardFragment);

            ShowcaseFragment showcaseFragment = (ShowcaseFragment)
                    fragmentManager.findFragmentByTag("showcase");
            if(showcaseFragment!=null) ft.hide(showcaseFragment);

        } else if(tag.equalsIgnoreCase("showcase")){
            DashboardFragment dashboardFragment = (DashboardFragment)
                    fragmentManager.findFragmentByTag("dashboard");
            if(dashboardFragment!=null) ft.hide(dashboardFragment);

            ShowcaseFragment showcaseFragment = (ShowcaseFragment)
                    fragmentManager.findFragmentByTag("showcase");
            if(showcaseFragment!=null) ft.show(showcaseFragment);
        }

        ft.commit();

What is a Sticky Broadcast?

A normal broadcast Intent is not available anymore after is was send and processed by the system. If you use the sendStickyBroadcast(Intent) method, the Intent is sticky, meaning the Intent you are sending stays around after the broadcast is complete.

you refer to my blog:enter link description here

HorizontalScrollView within ScrollView Touch Handling

Neevek's solution works better than Joel's on devices running 3.2 and above. There is a bug in Android that will cause java.lang.IllegalArgumentException: pointerIndex out of range if a gesture detector is used inside a scollview. To duplicate the issue, implement a custom scollview as Joel suggested and put a view pager inside. If you drag (don't lift you figure) to one direction (left/right) and then to the opposite, you will see the crash. Also in Joel's solution, if you drag the view pager by moving your finger diagonally, once your finger leave the view pager's content view area, the pager will spring back to its previous position. All these issues are more to do with Android's internal design or lack of it than Joel's implementation, which itself is a piece of smart and concise code.

http://code.google.com/p/android/issues/detail?id=18990

How to debug in Android Studio using adb over WiFi

just open settings / plugins / search " Android wifi adb and download it and connect your mobile using usb cabble once and its done

How to programmatically turn off WiFi on Android device?

You need the following permissions in your manifest file:

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission>

Then you can use the following in your activity class:

WifiManager wifiManager = (WifiManager) this.getApplicationContext().getSystemService(Context.WIFI_SERVICE); 
wifiManager.setWifiEnabled(true);
wifiManager.setWifiEnabled(false);

Use the following to check if it's enabled or not

boolean wifiEnabled = wifiManager.isWifiEnabled()

You'll find a nice tutorial on the subject on this site.

How to get URI from an asset File?

Works for WebView but seems to fail on URL.openStream(). So you need to distinguish file:// protocols and handle them via AssetManager as suggested.

Action Bar's onClick listener for the Home button

you should to delete your the Override onOptionsItemSelected and replate your onCreateOptionsMenu with this code

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_action_bar_finish_order_stop, menu);
        menu.getItem(0).setOnMenuItemClickListener(new FinishOrderStopListener(this, getApplication(), selectedChild));
        return true;

    }

How to use android emulator for testing bluetooth application?

Download Androidx86 from this This is an iso file, so you'd
need something like VMWare or VirtualBox to run it When creating the virtual machine, you need to set the type of guest OS as Linux instead of Other.

After creating the virtual machine set the network adapter to 'Bridged'. · Start the VM and select 'Live CD VESA' at boot.

Now you need to find out the IP of this VM. Go to terminal in VM (use Alt+F1 & Alt+F7 to toggle) and use the netcfg command to find this.

Now you need open a command prompt and go to your android install folder (on host). This is usually C:\Program Files\Android\android-sdk\platform-tools>.

Type adb connect IP_ADDRESS. There done! Now you need to add Bluetooth. Plug in your USB Bluetooth dongle/Bluetooth device.

In VirtualBox screen, go to Devices>USB devices. Select your dongle.

Done! now your Android VM has Bluetooth. Try powering on Bluetooth and discovering/paring with other devices.

Now all that remains is to go to Eclipse and run your program. The Android AVD manager should show the VM as a device on the list.

Alternatively, Under settings of the virtual machine, Goto serialports -> Port 1 check Enable serial port select a port number then select port mode as disconnected click ok. now, start virtual machine. Under Devices -> USB Devices -> you can find your laptop bluetooth listed. You can simply check the option and start testing the android bluetooth application .

Source

How to create Custom Ratings bar in Android

I need to add my solution which is WAY eaiser than the one above. We don't even need to use styles.

Create a selector file in the drawable folder:

custom_ratingbar_selector.xml

<?xml version="1.0" encoding="utf-8"?>
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
 <item android:id="@android:id/background"
    android:drawable="@drawable/star_off" />

 <item android:id="@android:id/secondaryProgress"
    android:drawable="@drawable/star_off" />

 <item android:id="@android:id/progress"
    android:drawable="@drawable/star_on" />

</layer-list>

In the layout set the selector file as progressDrawable:

 <RatingBar
        android:id="@+id/ratingBar2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="20dp"
        android:progressDrawable="@drawable/custom_ratingbar_selector"
        android:numStars="8"
        android:stepSize="0.2"
        android:rating="3.0" />

And that's all we need.

How to Change color of Button in Android when Clicked?

Save this code in drawable folder with "bg_button.xml" and call "@drawable/bg_button" as background of button in your xml:

<?xml version="1.0" encoding="UTF-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" >
        <shape>
            <solid
                android:color="#004F81" />
            <stroke
                android:width="1dp"
                android:color="#222222" />
            <corners
                android:radius="7dp" />
            <padding
                android:left="10dp"
                android:top="10dp"
                android:right="10dp"
                android:bottom="10dp" />
        </shape>
    </item>
    <item>
        <shape>
            <gradient
                android:startColor="#89cbee"
                android:endColor="#004F81"
                android:angle="270" />
            <stroke
                android:width="1dp"
                android:color="#4aa5d4" />
            <corners
                android:radius="7dp" />
            <padding
                android:left="10dp"
                android:top="10dp"
                android:right="10dp"
                android:bottom="10dp" />
        </shape>
    </item>
</selector>

"android.view.WindowManager$BadTokenException: Unable to add window" on buider.show()

I got this error, but mine was coming from the Toasts, not a Dialog.

I have Activity and Fragments in my layout. Code for the Toast was in the Activity class. Fragments gets loaded before the Activity.

I think the Toast code was hit before the Context/Activity finished initializing. I think it was the getApplicationContext() in the command Toast.makeText(getApplicationContext(), "onMenutItemActionCollapse called", Toast.LENGTH_SHORT).show();

android fragment- How to save states of views in a fragment when another fragment is pushed on top of it

i donot think onSaveInstanceState is a good solution. it just use for activity which had been destoryed.

From android 3.0 the Fragmen has been manager by FragmentManager, the condition is: one activity mapping manny fragments, when the fragment is added(not replace: it will recreated) in backStack, the view will be destored. when back to the last one, it will display as before.

So i think the fragmentManger and transaction is good enough to handle it.

Hex transparency in colors

Here's a correct table of percentages to hex values. E.g. for 50% white you'd use #80FFFFFF.

  • 100% — FF
  • 95% — F2
  • 90% — E6
  • 85% — D9
  • 80% — CC
  • 75% — BF
  • 70% — B3
  • 65% — A6
  • 60% — 99
  • 55% — 8C
  • 50% — 80
  • 45% — 73
  • 40% — 66
  • 35% — 59
  • 30% — 4D
  • 25% — 40
  • 20% — 33
  • 15% — 26
  • 10% — 1A
  • 5% — 0D
  • 0% — 00

(source)

how to store Image as blob in Sqlite & how to retrieve it?

in the DBAdaper i.e Data Base helper class declare the table like this

 private static final String USERDETAILS=
    "create table userdetails(usersno integer primary key autoincrement,userid text not null ,username text not null,password text not null,photo BLOB,visibility text not null);";

insert the values like this,

first convert the images as byte[]

ByteArrayOutputStream baos = new ByteArrayOutputStream();  
Bitmap bitmap = ((BitmapDrawable)getResources().getDrawable(R.drawable.common)).getBitmap();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);   
byte[] photo = baos.toByteArray(); 
db.insertUserDetails(value1,value2, value3, photo,value2);

in DEAdaper class

 public long insertUserDetails(String uname,String userid, String pass, byte[] photo,String visibility) 
{
    ContentValues initialValues = new ContentValues();
    initialValues.put("username", uname);
    initialValues.put("userid",userid);
    initialValues.put("password", pass);
    initialValues.put("photo",photo);
    initialValues.put("visibility",visibility);
    return db.insert("userdetails", null, initialValues);
}

retrieve the image as follows

Cursor cur=your query;
while(cur.moveToNext())
{
     byte[] photo=cur.getBlob(index of blob cloumn);
}

convert the byte[] into image

ByteArrayInputStream imageStream = new ByteArrayInputStream(photo);
Bitmap theImage= BitmapFactory.decodeStream(imageStream);

I think this content may solve your problem

What is the difference between List and ArrayList?

There's no difference between list implementations in both of your examples. There's however a difference in a way you can further use variable myList in your code.

When you define your list as:

List myList = new ArrayList();

you can only call methods and reference members that are defined in the List interface. If you define it as:

ArrayList myList = new ArrayList();

you'll be able to invoke ArrayList-specific methods and use ArrayList-specific members in addition to those whose definitions are inherited from List.

Nevertheless, when you call a method of a List interface in the first example, which was implemented in ArrayList, the method from ArrayList will be called (because the List interface doesn't implement any methods).

That's called polymorphism. You can read up on it.

How to use SearchView in Toolbar Android

If you want to add it directly in the toolbar.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.AppBarLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <android.support.v7.widget.Toolbar
        android:id="@+id/app_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <SearchView
            android:id="@+id/searchView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:iconifiedByDefault="false"
            android:queryHint="Search"
            android:layout_centerHorizontal="true" />

    </android.support.v7.widget.Toolbar>

</android.support.design.widget.AppBarLayout>

What's the Android ADB shell "dumpsys" tool and what are its benefits?

What's dumpsys and what are its benefit

dumpsys is an android tool that runs on the device and dumps interesting information about the status of system services.

Obvious benefits:

  1. Possibility to easily get system information in a simple string representation.
  2. Possibility to use dumped CPU, RAM, Battery, storage stats for a pretty charts, which will allow you to check how your application affects the overall device!

What information can we retrieve from dumpsys shell command and how we can use it

If you run dumpsys you would see a ton of system information. But you can use only separate parts of this big dump.

to see all of the "subcommands" of dumpsys do:

dumpsys | grep "DUMP OF SERVICE"

Output:

DUMP OF SERVICE SurfaceFlinger:
DUMP OF SERVICE accessibility:
DUMP OF SERVICE account:
DUMP OF SERVICE activity:
DUMP OF SERVICE alarm:
DUMP OF SERVICE appwidget:
DUMP OF SERVICE audio:
DUMP OF SERVICE backup:
DUMP OF SERVICE battery:
DUMP OF SERVICE batteryinfo:
DUMP OF SERVICE clipboard:
DUMP OF SERVICE connectivity:
DUMP OF SERVICE content:
DUMP OF SERVICE cpuinfo:
DUMP OF SERVICE device_policy:
DUMP OF SERVICE devicestoragemonitor:
DUMP OF SERVICE diskstats:
DUMP OF SERVICE dropbox:
DUMP OF SERVICE entropy:
DUMP OF SERVICE hardware:
DUMP OF SERVICE input_method:
DUMP OF SERVICE iphonesubinfo:
DUMP OF SERVICE isms:
DUMP OF SERVICE location:
DUMP OF SERVICE media.audio_flinger:
DUMP OF SERVICE media.audio_policy:
DUMP OF SERVICE media.player:
DUMP OF SERVICE meminfo:
DUMP OF SERVICE mount:
DUMP OF SERVICE netstat:
DUMP OF SERVICE network_management:
DUMP OF SERVICE notification:
DUMP OF SERVICE package:
DUMP OF SERVICE permission:
DUMP OF SERVICE phone:
DUMP OF SERVICE power:
DUMP OF SERVICE reboot:
DUMP OF SERVICE screenshot:
DUMP OF SERVICE search:
DUMP OF SERVICE sensor:
DUMP OF SERVICE simphonebook:
DUMP OF SERVICE statusbar:
DUMP OF SERVICE telephony.registry:
DUMP OF SERVICE throttle:
DUMP OF SERVICE usagestats:
DUMP OF SERVICE vibrator:
DUMP OF SERVICE wallpaper:
DUMP OF SERVICE wifi:
DUMP OF SERVICE window:

Some Dumping examples and output

1) Getting all possible battery statistic:

$~ adb shell dumpsys battery

You will get output:

Current Battery Service state:
AC powered: false
AC capacity: 500000
USB powered: true
status: 5
health: 2
present: true
level: 100
scale: 100
voltage:4201
temperature: 271 <---------- Battery temperature! %)
technology: Li-poly <---------- Battery technology! %)

2)Getting wifi informations

~$ adb shell dumpsys wifi

Output:

Wi-Fi is enabled
Stay-awake conditions: 3

Internal state:
interface tiwlan0 runState=Running
SSID: XXXXXXX BSSID: xx:xx:xx:xx:xx:xx, MAC: xx:xx:xx:xx:xx:xx, Supplicant state: COMPLETED, RSSI: -60, Link speed: 54, Net ID: 2, security: 0, idStr: null
ipaddr 192.168.1.xxx gateway 192.168.x.x netmask 255.255.255.0 dns1 192.168.x.x dns2 8.8.8.8 DHCP server 192.168.x.x lease 604800 seconds
haveIpAddress=true, obtainingIpAddress=false, scanModeActive=false
lastSignalLevel=2, explicitlyDisabled=false

Latest scan results:

Locks acquired: 28 full, 0 scan
Locks released: 28 full, 0 scan

Locks held:

3) Getting CPU info

~$ adb shell dumpsys cpuinfo

Output:

Load: 0.08 / 0.4 / 0.64
CPU usage from 42816ms to 34683ms ago:
system_server: 1% = 1% user + 0% kernel / faults: 16 minor
kdebuglog.sh: 0% = 0% user + 0% kernel / faults: 160 minor
tiwlan_wq: 0% = 0% user + 0% kernel
usb_mass_storag: 0% = 0% user + 0% kernel
pvr_workqueue: 0% = 0% user + 0% kernel
+sleep: 0% = 0% user + 0% kernel
+sleep: 0% = 0% user + 0% kernel
TOTAL: 6% = 1% user + 3% kernel + 0% irq

4)Getting memory usage informations

~$ adb shell dumpsys meminfo 'your apps package name'

Output:

** MEMINFO in pid 5527 [com.sec.android.widgetapp.weatherclock] **
                    native   dalvik    other    total
            size:     2868     5767      N/A     8635
       allocated:     2861     2891      N/A     5752
            free:        6     2876      N/A     2882
           (Pss):      532       80     2479     3091
  (shared dirty):      932     2004     6060     8996
    (priv dirty):      512       36     1872     2420

 Objects
           Views:        0        ViewRoots:        0
     AppContexts:        0       Activities:        0
          Assets:        3    AssetManagers:        3
   Local Binders:        2    Proxy Binders:        8
Death Recipients:        0
 OpenSSL Sockets:        0


 SQL
               heap:        0         MEMORY_USED:        0
 PAGECACHE_OVERFLOW:        0         MALLOC_SIZE:        0

If you want see the info for all processes, use ~$ adb shell dumpsys meminfo

enter image description here

dumpsys is ultimately flexible and useful tool!

If you want to use this tool do not forget to add permission into your android manifest automatically android.permission.DUMP

Try to test all commands to learn more about dumpsys. Happy dumping!

How to Consume WCF Service with Android

If I were doing this I would probably use WCF REST on the server and a REST library on the Java/Android client.

java.util.zip.ZipException: duplicate entry during packageAllDebugClassesForMultiDex

In my case the mentioned "duplicate entry" error arised after settingmultiDexEnable=true in the build.gradle.

and exact error which i was getting was below :

Error:Execution failed for task 
':android:transformClassesWithJarMergingForDebug'.
> com.android.build.api.transform.TransformException: 
java.util.zip.ZipException: duplicate entry: 
com/google/android/gms/internal/zzqx.class

So first thing I search for class which causes "duplicate entry" error using ctrl+n in Android Studio and searched for com/google/android/gms/internal/zzqx.class and then it was showing 2 entries for gms class with one version 8.4.0 and 1 with version 11.6.0 .

To fix it i made both to use 11.6.0 and it was fixed example

earlier

    compile "com.google.android.gms:play-services-games:11.6.0"
    compile "com.google.android.gms:play-services-auth:8.4.0"
    compile "com.google.android.gms:play-services-ads:11.6.0"

After

    compile "com.google.android.gms:play-services-games:11.6.0"
    compile "com.google.android.gms:play-services-auth:11.6.0"
    compile "com.google.android.gms:play-services-ads:11.6.0"

Rebuilding Fixed .

How to use Monitor (DDMS) tool to debug application

I think things (location) have changed little bit. For: Android Studio 1.2.1.1 Build @AI-141.1903250 - built on May 5, 2015

Franco Rondinis answer should be

To track memory allocation of objects:

  1. Start your app as described in Run Your App in Debug Mode.
  2. Click Android to open the Android DDMS tool window.
  3. Select your device from the dropdown list.
  4. Select your app by its package name from the list of running apps.
  5. On the Android DDMS tool window, select Memory tab.
  6. Click Start Allocation Tracking Interact with your app on the device. Click Stop Allocation Tracking (same icon)

how to start allocation tracking in android studio 1.2.1.1

How to send parameters from a notification-click to an activity?

Maybe a bit late, but: instead of this:

public void onNewIntent(Intent intent){
    Bundle extras = intent.getExtras();
    Log.i( "dbg","onNewIntent");

    if(extras != null){
        Log.i( "dbg", "Extra6 bool: "+ extras.containsKey("net.dbg.android.fjol"));
        Log.i( "dbg", "Extra6 val : "+ extras.getString("net.dbg.android.fjol"));

    }
    mTabsController.setActiveTab(TabsController.TAB_DOWNLOADS);
}

Use this:

Bundle extras = getIntent().getExtras();
if(extras !=null) {
    String value = extras.getString("keyName");
}

Programmatically change input type of the EditText from PASSWORD to NORMAL & vice versa

some dynamic situation holder.edit_pin.setInputType(InputType.TYPE_CLASS_NUMBER); will not work so better use both like that

holder.edit_pin.setInputType(InputType.TYPE_CLASS_NUMBER);
holder.edit_pin.setTransformationMethod(PasswordTransformationMethod.getInstance());

Note : this is suitable for when you are using dynamic controls like using arrayaapter

How to change proxy settings in Android (especially in Chrome)

Found one solution for WIFI (works for Android 4.3, 4.4):

  1. Connect to WIFI network (e.g. 'Alex')
  2. Settings->WIFI
  3. Long tap on connected network's name (e.g. on 'Alex')
  4. Modify network config-> Show advanced options
  5. Set proxy settings

How to create a TextArea in Android

Try this:

<EditText
        android:id="@+id/edit_text"
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:inputType="text|textMultiLine"
        android:gravity="top"/>

How to retrieve the dimensions of a view?

As F.X. mentioned, you can use an OnLayoutChangeListener to the view that you want to track itself

view.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
    @Override
    public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
        // Make changes
    }
});

You can remove the listener in the callback if you only want the initial layout.

How to create a date and time picker in Android?

Call the time picker dialog in the DatePicker update time method. It'll not be called at the same time but when you press DatePicker set button. The time picker dialog will open. The method is given below.

package com.android.date;

import java.util.Calendar;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.Dialog;
import android.app.TimePickerDialog;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;
import android.widget.TimePicker;

public class datepicker extends Activity {

    private TextView mDateDisplay;
    private Button mPickDate;
    private int mYear;
    private int mMonth;
    private int mDay;
    private TextView mTimeDisplay;
    private Button mPickTime;

    private int mhour;
    private int mminute;

    static final int TIME_DIALOG_ID = 1;

    static final int DATE_DIALOG_ID = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mDateDisplay =(TextView)findViewById(R.id.date);
        mPickDate =(Button)findViewById(R.id.datepicker);
        mTimeDisplay = (TextView) findViewById(R.id.time);
        mPickTime = (Button) findViewById(R.id.timepicker);

        //Pick time's click event listener
        mPickTime.setOnClickListener(new View.OnClickListener(){

            @Override
            public void onClick(View v) {
                showDialog(TIME_DIALOG_ID);
            }
        });

        //PickDate's click event listener 
        mPickDate.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                showDialog(DATE_DIALOG_ID);
            }
        });

        final Calendar c = Calendar.getInstance();
        mYear = c.get(Calendar.YEAR);
        mMonth = c.get(Calendar.MONTH);
        mDay = c.get(Calendar.DAY_OF_MONTH);
        mhour = c.get(Calendar.HOUR_OF_DAY);
        mminute = c.get(Calendar.MINUTE);
    }

    //-------------------------------------------update date---//    
    private void updateDate() {
        mDateDisplay.setText(
            new StringBuilder()
                    // Month is 0 based so add 1
                    .append(mDay).append("/")
                    .append(mMonth + 1).append("/")
                    .append(mYear).append(" "));
        showDialog(TIME_DIALOG_ID);
    }

      //-------------------------------------------update time---//    
    public void updatetime() {
        mTimeDisplay.setText(
                new StringBuilder()
                        .append(pad(mhour)).append(":")
                        .append(pad(mminute))); 
    }

    private static String pad(int c) {
        if (c >= 10)
            return String.valueOf(c);
        else
            return "0" + String.valueOf(c);


    //Datepicker dialog generation  

    private DatePickerDialog.OnDateSetListener mDateSetListener =
        new DatePickerDialog.OnDateSetListener() {

            public void onDateSet(DatePicker view, int year, 
                                  int monthOfYear, int dayOfMonth) {
                mYear = year;
                mMonth = monthOfYear;
                mDay = dayOfMonth;
                updateDate();
            }
        };


     // Timepicker dialog generation
        private TimePickerDialog.OnTimeSetListener mTimeSetListener =
            new TimePickerDialog.OnTimeSetListener() {
                public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
                    mhour = hourOfDay;
                    mminute = minute;
                    updatetime();
                }
            };

        @Override
        protected Dialog onCreateDialog(int id) {
            switch (id) {
            case DATE_DIALOG_ID:
                return new DatePickerDialog(this,
                            mDateSetListener,
                            mYear, mMonth, mDay);

            case TIME_DIALOG_ID:
                return new TimePickerDialog(this,
                        mTimeSetListener, mhour, mminute, false);

            }
            return null;
        }
}

the main.xml is given below

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <TextView  
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:text="@string/hello"/>

    <TextView android:id="@+id/time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text=""/>

    <Button
        android:id="@+id/timepicker"
        android:text="Change Time" 
        android:layout_height="wrap_content" 
        android:layout_width="wrap_content"/>

    <TextView 
        android:id="@+id/date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text=""/>

    <Button android:id="@+id/datepicker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="200dp"
        android:text="Change the date"/>

</LinearLayout>

How to press back button in android programmatically?

Sometimes is useful to override method onBackPressed() because in case you work with fragments and you're changing between them if you push backbutton they return to the previous fragment.

How to set the holo dark theme in a Android app?

According the android.com, you only need to set it in the AndroidManifest.xml file:

http://developer.android.com/guide/topics/ui/themes.html#ApplyATheme

Adding the theme attribute to your application element worked for me:

--AndroidManifest.xml--

...

<application ...

  android:theme="@android:style/Theme.Holo"/>
  ...

</application>

Android, How can I Convert String to Date?

SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy");
Date d = dateFormat.parse(datestring)

How do I use the Simple HTTP client in Android?

You can use this code:

int count;
            try {
                URL url = new URL(f_url[0]);
                URLConnection conection = url.openConnection();
                conection.setConnectTimeout(TIME_OUT);
                conection.connect();
                // Getting file length
                int lenghtOfFile = conection.getContentLength();
                // Create a Input stream to read file - with 8k buffer
                InputStream input = new BufferedInputStream(url.openStream(),
                        8192);
                // Output stream to write file
                OutputStream output = new FileOutputStream(
                        "/sdcard/9androidnet.jpg");

                byte data[] = new byte[1024];
                long total = 0;
                while ((count = input.read(data)) != -1) {
                    total += count;
                    // publishing the progress....
                    // After this onProgressUpdate will be called
                    publishProgress("" + (int) ((total * 100) / lenghtOfFile));
                    // writing data to file
                    output.write(data, 0, count);
                }
                // flushing output
                output.flush();
                // closing streams
                output.close();
                input.close();
            } catch (SocketTimeoutException e) {
                connectionTimeout=true;
            } catch (Exception e) {
                Log.e("Error: ", e.getMessage());
            }

How to update a menu item shown in the ActionBar?

I have used this code:

public boolean onPrepareOptionsMenu (Menu menu) {       
    MenuInflater inflater = getMenuInflater();
    TextView title  = (TextView) findViewById(R.id.title);
    menu.getItem(0).setTitle(
        getString(R.string.payFor) + " " + title.getText().toString());
    menu.getItem(1).setTitle(getString(R.string.payFor) + "...");
    return true;        
}

And worked like a charm to me you can find OnPrepareOptionsMenu here

Is it possible to start activity through adb shell?

adb shell am broadcast -a android.intent.action.xxx

Mention xxx as the action that you mentioned in the manifest file.

Change Spinner dropdown icon

dummy.xml(remember image size should be less)

<?xml version="1.0" encoding="utf-8"?>
    <selector xmlns:android="http://schemas.android.com/apk/res/android">
        <item>
            <layer-list android:opacity="transparent">
                <item android:width="60dp" android:gravity="left" android:start="20dp">
                    <bitmap  android:src="@drawable/down_button_dummy_dummy" android:gravity="left"/>
                </item>
            </layer-list>
        </item>
    </selector>

layout file snippet be like

<android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:cardUseCompatPadding="true"
        app:cardElevation="5dp"
        >
     <Spinner
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:background="@drawable/dummy">

     </Spinner>
    </android.support.v7.widget.CardView>

click to see result layout image

How to send objects through bundle

1.A very direct and easy to use example, make object to be passed implement Serializable.

class Object implements Serializable{
    String firstName;
   String lastName;
}

2.pass object in bundle

Bundle bundle = new Bundle();
Object Object = new Object();
bundle.putSerializable("object", object);

3.get passed object from bundle as Serializable then cast to Object.

Object object = (Object) getArguments().getSerializable("object");

Get the Application Context In Fragment In Android?

Use

getActivity().getApplicationContext()

to obtain the context in any fragment

Best practice for instantiating a new Android Fragment

Some kotlin code:

companion object {
    fun newInstance(first: String, second: String) : SampleFragment {
        return SampleFragment().apply {
            arguments = Bundle().apply {
                putString("firstString", first)
                putString("secondString", second)
            }
        }
    }
}

And you can get arguments with this:

val first: String by lazy { arguments?.getString("firstString") ?: "default"}
val second: String by lazy { arguments?.getString("secondString") ?: "default"}

String.equals() with multiple conditions (and one action on result)

Possibilities:

  • Use String.equals():

    if (some_string.equals("john") ||
        some_string.equals("mary") ||
        some_string.equals("peter"))
    {
    }
    
  • Use a regular expression:

    if (some_string.matches("john|mary|peter"))
    {
    }
    
  • Store a list of strings to be matched against in a Collection and search the collection:

    Set<String> names = new HashSet<String>();
    names.add("john");
    names.add("mary");
    names.add("peter");
    
    if (names.contains(some_string))
    {
    }
    

What is meant by Ems? (Android TextView)

ems is a unit of measurement

The name em was originally a reference to the width of the capital M. It sets the width of a TextView/EditText to fit a text of n 'M' letters regardless of the actual text extension and text size.

Eg :

android:ems Makes the EditText be exactly this many ems wide.

<EditText
    android:ems="2"
/>

denotes twice the width of letter M is created.

Disable scrolling in all mobile devices

html, body {
  overflow-x: hidden;
}
body {
  position: relative;
}

The position relative is important, and i just stumbled about it. Could not make it work without it.

Android Fragment no view found for ID?

Another scenario I have met. If you use nested fragments, say a ViewPager in a Fragment with it's pages also Fragments.

When you do Fragment transaction in the inner fragment(page of ViewPager), you will need

FragmentManager fragmentManager = getActivity().getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

getActivity() is the key here. ...

How to capture the android device screen content?

[Based on Android source code:]

At the C++ side, the SurfaceFlinger implements the captureScreen API. This is exposed over the binder IPC interface, returning each time a new ashmem area that contains the raw pixels from the screen. The actual screenshot is taken through OpenGL.

For the system C++ clients, the interface is exposed through the ScreenshotClient class, defined in <surfaceflinger_client/SurfaceComposerClient.h> for Android < 4.1; for Android > 4.1 use <gui/SurfaceComposerClient.h>

Before JB, to take a screenshot in a C++ program, this was enough:

ScreenshotClient ssc;
ssc.update();

With JB and multiple displays, it becomes slightly more complicated:

ssc.update(
    android::SurfaceComposerClient::getBuiltInDisplay(
        android::ISurfaceComposer::eDisplayIdMain));

Then you can access it:

do_something_with_raw_bits(ssc.getPixels(), ssc.getSize(), ...);

Using the Android source code, you can compile your own shared library to access that API, and then expose it through JNI to Java. To create a screen shot form your app, the app has to have the READ_FRAME_BUFFER permission. But even then, apparently you can create screen shots only from system applications, i.e. ones that are signed with the same key as the system. (This part I still don't quite understand, since I'm not familiar enough with the Android Permissions system.)

Here is a piece of code, for JB 4.1 / 4.2:

#include <utils/RefBase.h>
#include <binder/IBinder.h>
#include <binder/MemoryHeapBase.h>
#include <gui/ISurfaceComposer.h>
#include <gui/SurfaceComposerClient.h>

static void do_save(const char *filename, const void *buf, size_t size) {
    int out = open(filename, O_RDWR|O_CREAT, 0666);
    int len = write(out, buf, size);
    printf("Wrote %d bytes to out.\n", len);
    close(out);
}

int main(int ac, char **av) {
    android::ScreenshotClient ssc;
    const void *pixels;
    size_t size;
    int buffer_index;

    if(ssc.update(
        android::SurfaceComposerClient::getBuiltInDisplay(
            android::ISurfaceComposer::eDisplayIdMain)) != NO_ERROR ){
        printf("Captured: w=%d, h=%d, format=%d\n");
        ssc.getWidth(), ssc.getHeight(), ssc.getFormat());
        size = ssc.getSize();
        do_save(av[1], pixels, size);
    }
    else
        printf(" screen shot client Captured Failed");
    return 0;
}

How do I disable orientation change on Android?

In Visual Studio Xamarin:

  1. Add:

using Android.Content.PM; to you activity namespace list.

  1. Add:

[Activity(ScreenOrientation = Android.Content.PM.ScreenOrientation.Portrait)]

as an attribute to you class, like that:

[Activity(ScreenOrientation = ScreenOrientation.Portrait)]
public class MainActivity : Activity
{...}

Get all child views inside LinearLayout at once

Get all views from any type of layout

public List<View> getAllViews(ViewGroup layout){
        List<View> views = new ArrayList<>();
        for(int i =0; i< layout.getChildCount(); i++){
            views.add(layout.getChildAt(i));
        }
        return views;
}

Get all TextView from any type of layout

public List<TextView> getAllTextViews(ViewGroup layout){
        List<TextView> views = new ArrayList<>();
        for(int i =0; i< layout.getChildCount(); i++){
            View v =layout.getChildAt(i);
            if(v instanceof TextView){
                views.add((TextView)v);
            }
        }
        return views;
}

Android, ListView IllegalStateException: "The content of the adapter has changed but ListView did not receive a notification"

In my case I called the method GetFilter() on an adapter from the TextWatcher() method on main Activity, and I added the data with a For loop on GetFilter(). The solution was change the For loop to AfterTextChanged() sub method on main Activity and delete the call to GetFilter()

Gson library in Android Studio

Use gradle dependencies to get the Gson in your project. Your application build.gradle should look like this-

dependencies {
  implementation 'com.google.code.gson:gson:2.8.2'
}

Android check permission for LocationManager

if you are working on dynamic permissions and any permission like ACCESS_FINE_LOCATION,ACCESS_COARSE_LOCATION giving error "cannot resolve method PERMISSION_NAME" in this case write you code with permission name and then rebuild your project this will regenerate the manifest(Manifest.permission) file.

How to autoplay HTML5 mp4 video on Android?

Here is a plugin for PhoneGap which solved the problem for me: https://build.phonegap.com/plugins/1031

I simply included it in my config.xml

Nexus 7 (2013) and Win 7 64 - cannot install USB driver despite checking many forums and online resources

Asus Nexus 7 on my Windows 7 64 bits computer for development purposes :

I tried to install the driver for the nexus 7 manually like explained in the official tutorial of Asus

Unfortunately, I had an error, Windows couldn't recognize the driver.

I tried to change the USB connection mode to PTP or MTP by going in the storage menu and clicking on the top right menu . In both cases, windows recognize the devices but it still didn't work in debugging mode.

The only way it worked for me is by installing : adb universal installer . I scanned it before clicking on the executable, it seems to be fine.

Create folder in Android

Add this permission in Manifest,
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

File folder = new File(Environment.getExternalStorageDirectory() + 
                             File.separator + "TollCulator");
boolean success = true;
if (!folder.exists()) {
    success = folder.mkdirs();
}
if (success) {
    // Do something on success
} else {
    // Do something else on failure 
}

when u run the application go too DDMS->File Explorer->mnt folder->sdcard folder->toll-creation folder

Failed to load AppCompat ActionBar with unknown error in android studio

in android 3.0.0 canary 6 you must change all 2.6.0 beta2 to beta1 (appcompat,design,supportvector)

Android: ProgressDialog.show() crashes with getApplicationContext

I am using Android version 2.1 with API Level 7. I faced with this (or similar) problem and solved by using this:

Dialog dialog = new Dialog(this);

instead of this:

Dialog dialog = new Dialog(getApplicationContext());

Hope this helps :)

Android and setting alpha for (image) view alpha

Maybe a helpful alternative for a plain-colored background:

Put a LinearLayout over the ImageView and use the LinearLayout as a opacity filter. In the following a small example with a black background:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FF000000" >

<RelativeLayout
    android:id="@+id/relativeLayout2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/icon_stop_big" />

    <LinearLayout
        android:id="@+id/opacityFilter"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="#CC000000"
        android:orientation="vertical" >
    </LinearLayout>
</RelativeLayout>

Vary the android:background attribute of the LinearLayout between #00000000 (fully transparent) and #FF000000 (fully opaque).

How to filter a RecyclerView with a SearchView

In Adapter:

public void setFilter(List<Channel> newList){
        mChannels = new ArrayList<>();
        mChannels.addAll(newList);
        notifyDataSetChanged();
    }

In Activity:

searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                newText = newText.toLowerCase();
                ArrayList<Channel> newList = new ArrayList<>();
                for (Channel channel: channels){
                    String channelName = channel.getmChannelName().toLowerCase();
                    if (channelName.contains(newText)){
                        newList.add(channel);
                    }
                }
                mAdapter.setFilter(newList);
                return true;
            }
        });

Android Lint contentDescription warning

For graphical elements that are purely decorative, set their respective android:contentDescription XML attributes to "@null".

If your app only supports devices running Android 4.1 (API level 16) or higher, you can instead set these elements' android:importantForAccessibility XML attributes to "no"

android get all contacts

Improving on the answer of @Adiii - It Will Cleanup The Phone Number and Remove All Duplicates

Declare a Global Variable

// Hash Maps
Map<String, String> namePhoneMap = new HashMap<String, String>();

Then Use The Function Below

private void getPhoneNumbers() {

        Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null);

        // Loop Through All The Numbers
        while (phones.moveToNext()) {

            String name = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
            String phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));

            // Cleanup the phone number
            phoneNumber = phoneNumber.replaceAll("[()\\s-]+", "");

            // Enter Into Hash Map
            namePhoneMap.put(phoneNumber, name);

        }

        // Get The Contents of Hash Map in Log
        for (Map.Entry<String, String> entry : namePhoneMap.entrySet()) {
            String key = entry.getKey();
            Log.d(TAG, "Phone :" + key);
            String value = entry.getValue();
            Log.d(TAG, "Name :" + value);
        }

        phones.close();

    }

Remember in the above example the key is phone number and value is a name so read your contents like 998xxxxx282->Mahatma Gandhi instead of Mahatma Gandhi->998xxxxx282

Android background music service

I have found two great resources to share, if anyone else come across this thread via Google, this may help them ( 2018 ). One is this video tutorial in which you'll see practically how service works, this is good for starters.

Link :- https://www.youtube.com/watch?v=p2ffzsCqrs8

Other is this website which will really help you with background audio player.

Link :- https://www.dev2qa.com/android-play-audio-file-in-background-service-example/

Good Luck :)

Execution failed for task 'app:mergeDebugResources' Crunching Cruncher....png failed

If you're running Linux, try this:

sudo apt-get install lib32stdc++6 lib32z1

It is from here.

android pinch zoom

Updated Answer

Code can be found here : official-doc

Answer Outdated

Check out the following links which may help you

Best examples are provided in the below links, which you can refactor to meet your requirements.

  1. implementing-the-pinch-zoom-gestur

  2. Android-pinch

  3. GestureDetector.SimpleOnGestureListener

Switching to landscape mode in Android Emulator

make sure that your hardware keyboard is enable while creating your AVD

-launch the emulator -install your app -launch your app -make sure that your Num lock is on -Press '7' &'9' from your num pad to change your orientation landscape to portrait & portrait to landscape.

Removing an activity from the history stack

Just call this.finish() before startActivity(intent) like this-

       Intent intent = new Intent(ActivityOne.this, ActivityTwo.class);
        this.finish();
        startActivity(intent);

Android Overriding onBackPressed()

At first you must consider that if your activity which I called A extends another activity (B) and in both of

them you want to use onbackpressed function then every code you have in B runs in A too. So if you want to separate these you should separate them. It means that A should not extend B , then you can have onbackpressed separately for each of them.

How to change package name in android studio?

It can be done very easily in one step. You don't have to touch AndroidManifest. Instead do the following:

  1. right click on the root folder of your project.
  2. Click "Open Module Setting".
  3. Go to the Flavours tab.
  4. Change the applicationID to whatever package name you want. Press OK.

ListView inside ScrollView is not scrolling on Android

replace ListView by RecycleView inside ScrollView. it runs smoothly without additional source code:

 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.hung.recycleviewtest.MainActivityFragment"
    >
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <android.support.v7.widget.RecyclerView
            android:id="@+id/recycle_view"
            android:layout_width="match_parent"
            android:layout_height="400dp"
            android:background="@android:color/darker_gray"/>
        <android.support.v7.widget.RecyclerView
            android:id="@+id/recycle_view_a"
            android:layout_marginTop="40dp"
            android:layout_below="@id/recycle_view"
            android:layout_width="match_parent"
            android:layout_height="400dp"
            android:background="@android:color/darker_gray"/>
    </RelativeLayout>

</ScrollView>

How to determine the screen width in terms of dp or dip at runtime in Android?

Answer in kotlin:

  context?.let {
        val displayMetrics = it.resources.displayMetrics
        val dpHeight = displayMetrics.heightPixels / displayMetrics.density
        val dpWidth = displayMetrics.widthPixels / displayMetrics.density
    }

Error: No toolchains found in the NDK toolchains folder for ABI with prefix: llvm

I solved this question by unInstalled ndk, becasuse I dont't need it

How to SHA1 hash a string in Android?

final MessageDigest digest = MessageDigest.getInstance("SHA-1");
result = digest.digest(stringToHash.getBytes("UTF-8"));

// Another way to construct HEX, my previous post was only the method like your solution
StringBuilder sb = new StringBuilder();

for (byte b : result) // This is your byte[] result..
{
    sb.append(String.format("%02X", b));
}

String messageDigest = sb.toString();

Simple example for Intent and Bundle

Try this: if you need pass values between the activities you use this...

This is code for Main_Activity put the values to intent

 String name="aaaa";
 Intent intent=new Intent(Main_Activity.this,Other_Activity.class);
 intent.putExtra("name", name);
 startActivity(intent);

This code for Other_Activity and get the values form intent

    Bundle b = new Bundle();
    b = getIntent().getExtras();
    String name = b.getString("name");

How update the _id of one MongoDB Document?

You cannot update it. You'll have to save the document using a new _id, and then remove the old document.

// store the document in a variable
doc = db.clients.findOne({_id: ObjectId("4cc45467c55f4d2d2a000002")})

// set a new _id on the document
doc._id = ObjectId("4c8a331bda76c559ef000004")

// insert the document, using the new _id
db.clients.insert(doc)

// remove the document with the old _id
db.clients.remove({_id: ObjectId("4cc45467c55f4d2d2a000002")})

How to get pandas.DataFrame columns containing specific dtype

To get the column names from pandas dataframe in python3- Here I am creating a data frame from a fileName.csv file

>>> import pandas as pd
>>> df = pd.read_csv('fileName.csv')
>>> columnNames = list(df.head(0)) 
>>> print(columnNames)

How to tell which commit a tag points to in Git?

Can use below, It will give the commit hash
git show -s --format=%H <tag>^{commit}

If abbreviated commit hash required, git show -s --format=%h <tag>^{commit}

How to test an Oracle Stored Procedure with RefCursor return type?

In Toad 10.1.1.8 I use:

variable salida refcursor
exec MY_PKG.MY_PRC(1, 2, 3, :salida)  -- 1, 2, 3 are params
print salida

Then, Execute as Script.

Adding three months to a date in PHP

The following should work, but you may need to change the format:

echo date('l F jS, Y (m-d-Y)', strtotime('+3 months', strtotime($DateToAdjust)));

Add new field to every document in a MongoDB collection

if you are using mongoose try this,after mongoose connection

async ()=> await Mongoose.model("collectionName").updateMany({}, {$set: {newField: value}})

Blur the edges of an image or background image with CSS

If what you're looking for is simply to blur the image edges you can simply use the box-shadow with an inset.

Working example: http://jsfiddle.net/d9Q5H/1/

Screenshot

HTML:

<div class="image-blurred-edge"></div>

CSS

.image-blurred-edge {
    background-image: url('http://lorempixel.com/200/200/city/9');
    width: 200px;
    height: 200px;
    /* you need to match the shadow color to your background or image border for the desired effect*/
    box-shadow: 0 0 8px 8px white inset;
}

How to install python-dateutil on Windows?

I followed several suggestions in this list without success. Finally got it installed on Windows using this method: I extracted the zip file and placed the folders under my python27 folder. In a DOS window, I navigated to the installed root folder from extracting the zip file (python-dateutil-2.6.0), then issued this command:

.\python setup.py install

Whammo-bammo it all worked.

"No X11 DISPLAY variable" - what does it mean?

Are you running this from within an X11 environment? You can use a terminal window, but it has to be within X (either after a graphical login, or by running startx).

If you're already within a graphical environment, try export DISPLAY=:0 for bash like shells (bash, sh, etc) or setenv DISPLAY :0 for C shell based shells (csh, tcsh, etc)

If you've connected from another machine via SSH, you use the -X option to display the graphical interface on the machine you're sitting at (provided there's an X server running there (such as xming for windows, and your standard Linux X server).

how to convert current date to YYYY-MM-DD format with angular 2

Here is a very nice and compact way to do this, you can also change this function as your case needs:

result: 03.11.2017

//get date now function
    getNowDate() {
    //return string
    var returnDate = "";
    //get datetime now
    var today = new Date();
    //split
    var dd = today.getDate();
    var mm = today.getMonth() + 1; //because January is 0! 
    var yyyy = today.getFullYear();
    //Interpolation date
    if (dd < 10) {
        returnDate += `0${dd}.`;
    } else {
        returnDate += `${dd}.`;
    }

    if (mm < 10) {
        returnDate += `0${mm}.`;
    } else {
        returnDate += `${mm}.`;
    }
    returnDate += yyyy;
    return returnDate;
}

Entity framework self referencing loop detected

The main problem is that serializing an entity model which has relation with other entity model(Foreign key relationship). This relation causes self referencing this will throw exception while serialization to json or xml. There are lots of options. Without serializing entity models by using custom models.Values or data from entity model data mapped to custom models(object mapping) using Automapper or Valueinjector then return request and it will serialize without any other issues. Or you can serialize entity model so first disable proxies in entity model

public class LabEntities : DbContext
{
   public LabEntities()
   {
      Configuration.ProxyCreationEnabled = false;
   }

To preserve object references in XML, you have two options. The simpler option is to add [DataContract(IsReference=true)] to your model class. The IsReference parameter enables oibject references. Remember that DataContract makes serialization opt-in, so you will also need to add DataMember attributes to the properties:

[DataContract(IsReference=true)]
public partial class Employee
{
   [DataMember]
   string dfsd{get;set;}
   [DataMember]
   string dfsd{get;set;}
   //exclude  the relation without giving datamember tag
   List<Department> Departments{get;set;}
}

In Json format in global.asax

var json = GlobalConfiguration.Configuration.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling = 
    Newtonsoft.Json.PreserveReferencesHandling.All;

in xml format

var xml = GlobalConfiguration.Configuration.Formatters.XmlFormatter;
var dcs = new DataContractSerializer(typeof(Employee), null, int.MaxValue, 
    false, /* preserveObjectReferences: */ true, null);
xml.SetSerializer<Employee>(dcs);

Node.js spawn child process and get terminal output live

I'm still getting my feet wet with Node.js, but I have a few ideas. first, I believe you need to use execFile instead of spawn; execFile is for when you have the path to a script, whereas spawn is for executing a well-known command that Node.js can resolve against your system path.

1. Provide a callback to process the buffered output:

var child = require('child_process').execFile('path/to/script', [ 
    'arg1', 'arg2', 'arg3', 
], function(err, stdout, stderr) { 
    // Node.js will invoke this callback when process terminates.
    console.log(stdout); 
});  

2. Add a listener to the child process' stdout stream (9thport.net)

var child = require('child_process').execFile('path/to/script', [ 
    'arg1', 'arg2', 'arg3' ]); 
// use event hooks to provide a callback to execute when data are available: 
child.stdout.on('data', function(data) {
    console.log(data.toString()); 
});

Further, there appear to be options whereby you can detach the spawned process from Node's controlling terminal, which would allow it to run asynchronously. I haven't tested this yet, but there are examples in the API docs that go something like this:

child = require('child_process').execFile('path/to/script', [ 
    'arg1', 'arg2', 'arg3', 
], { 
    // detachment and ignored stdin are the key here: 
    detached: true, 
    stdio: [ 'ignore', 1, 2 ]
}); 
// and unref() somehow disentangles the child's event loop from the parent's: 
child.unref(); 
child.stdout.on('data', function(data) {
    console.log(data.toString()); 
});

Wildcards in jQuery selectors

When you have a more complex id string the double quotes are mandatory.

For example if you have an id like this: id="2.2", the correct way to access it is: $('input[id="2.2"]')

As much as possible use the double quotes, for safety reasons.

Code signing is required for product type Unit Test Bundle in SDK iOS 8.0

The other advice here didn't help me, but I fixed this error by going to Product > Scheme > Edit Scheme. Then I clicked Build on the left hand side and deselected any checkboxes next to AppNameTests. I'm using XCode 6.3

enter image description here

How to compare each item in a list with the rest, only once?

I think using enumerate on the outer loop and using the index to slice the list on the inner loop is pretty Pythonic:

for index, this in enumerate(mylist):
    for that in mylist[index+1:]:
        compare(this, that)

How do I tell Python to convert integers into words

You have to use a dictionnary/array. For example :

 to_19= ['zero','one','two','three','four','five','six','seven','eight','nine'..'nineteen']
 tens = ['twenty'...'ninety']

And you could generate the string of a number by doing, for example :

 if len(str(number)) == 2 and  number > 20:
       word_number = tens[str(number)[0]]+' '+units[str(number)[0]]

You have to check if the last figure is not a zero and so on.. classic value checking.

It reminds a project euler challenge (problem 17).. you should try to find some solutions about it

Hope it helps

Execute a command line binary with Node.js

I just wrote a Cli helper to deal with Unix/windows easily.

Javascript:

define(["require", "exports"], function (require, exports) {
    /**
     * Helper to use the Command Line Interface (CLI) easily with both Windows and Unix environments.
     * Requires underscore or lodash as global through "_".
     */
    var Cli = (function () {
        function Cli() {}
            /**
             * Execute a CLI command.
             * Manage Windows and Unix environment and try to execute the command on both env if fails.
             * Order: Windows -> Unix.
             *
             * @param command                   Command to execute. ('grunt')
             * @param args                      Args of the command. ('watch')
             * @param callback                  Success.
             * @param callbackErrorWindows      Failure on Windows env.
             * @param callbackErrorUnix         Failure on Unix env.
             */
        Cli.execute = function (command, args, callback, callbackErrorWindows, callbackErrorUnix) {
            if (typeof args === "undefined") {
                args = [];
            }
            Cli.windows(command, args, callback, function () {
                callbackErrorWindows();

                try {
                    Cli.unix(command, args, callback, callbackErrorUnix);
                } catch (e) {
                    console.log('------------- Failed to perform the command: "' + command + '" on all environments. -------------');
                }
            });
        };

        /**
         * Execute a command on Windows environment.
         *
         * @param command       Command to execute. ('grunt')
         * @param args          Args of the command. ('watch')
         * @param callback      Success callback.
         * @param callbackError Failure callback.
         */
        Cli.windows = function (command, args, callback, callbackError) {
            if (typeof args === "undefined") {
                args = [];
            }
            try {
                Cli._execute(process.env.comspec, _.union(['/c', command], args));
                callback(command, args, 'Windows');
            } catch (e) {
                callbackError(command, args, 'Windows');
            }
        };

        /**
         * Execute a command on Unix environment.
         *
         * @param command       Command to execute. ('grunt')
         * @param args          Args of the command. ('watch')
         * @param callback      Success callback.
         * @param callbackError Failure callback.
         */
        Cli.unix = function (command, args, callback, callbackError) {
            if (typeof args === "undefined") {
                args = [];
            }
            try {
                Cli._execute(command, args);
                callback(command, args, 'Unix');
            } catch (e) {
                callbackError(command, args, 'Unix');
            }
        };

        /**
         * Execute a command no matters what's the environment.
         *
         * @param command   Command to execute. ('grunt')
         * @param args      Args of the command. ('watch')
         * @private
         */
        Cli._execute = function (command, args) {
            var spawn = require('child_process').spawn;
            var childProcess = spawn(command, args);

            childProcess.stdout.on("data", function (data) {
                console.log(data.toString());
            });

            childProcess.stderr.on("data", function (data) {
                console.error(data.toString());
            });
        };
        return Cli;
    })();
    exports.Cli = Cli;
});

Typescript original source file:

 /**
 * Helper to use the Command Line Interface (CLI) easily with both Windows and Unix environments.
 * Requires underscore or lodash as global through "_".
 */
export class Cli {

    /**
     * Execute a CLI command.
     * Manage Windows and Unix environment and try to execute the command on both env if fails.
     * Order: Windows -> Unix.
     *
     * @param command                   Command to execute. ('grunt')
     * @param args                      Args of the command. ('watch')
     * @param callback                  Success.
     * @param callbackErrorWindows      Failure on Windows env.
     * @param callbackErrorUnix         Failure on Unix env.
     */
    public static execute(command: string, args: string[] = [], callback ? : any, callbackErrorWindows ? : any, callbackErrorUnix ? : any) {
        Cli.windows(command, args, callback, function () {
            callbackErrorWindows();

            try {
                Cli.unix(command, args, callback, callbackErrorUnix);
            } catch (e) {
                console.log('------------- Failed to perform the command: "' + command + '" on all environments. -------------');
            }
        });
    }

    /**
     * Execute a command on Windows environment.
     *
     * @param command       Command to execute. ('grunt')
     * @param args          Args of the command. ('watch')
     * @param callback      Success callback.
     * @param callbackError Failure callback.
     */
    public static windows(command: string, args: string[] = [], callback ? : any, callbackError ? : any) {
        try {
            Cli._execute(process.env.comspec, _.union(['/c', command], args));
            callback(command, args, 'Windows');
        } catch (e) {
            callbackError(command, args, 'Windows');
        }
    }

    /**
     * Execute a command on Unix environment.
     *
     * @param command       Command to execute. ('grunt')
     * @param args          Args of the command. ('watch')
     * @param callback      Success callback.
     * @param callbackError Failure callback.
     */
    public static unix(command: string, args: string[] = [], callback ? : any, callbackError ? : any) {
        try {
            Cli._execute(command, args);
            callback(command, args, 'Unix');
        } catch (e) {
            callbackError(command, args, 'Unix');
        }
    }

    /**
     * Execute a command no matters what's the environment.
     *
     * @param command   Command to execute. ('grunt')
     * @param args      Args of the command. ('watch')
     * @private
     */
    private static _execute(command, args) {
        var spawn = require('child_process').spawn;
        var childProcess = spawn(command, args);

        childProcess.stdout.on("data", function (data) {
            console.log(data.toString());
        });

        childProcess.stderr.on("data", function (data) {
            console.error(data.toString());
        });
    }
}

Example of use:

    Cli.execute(Grunt._command, args, function (command, args, env) {
        console.log('Grunt has been automatically executed. (' + env + ')');

    }, function (command, args, env) {
        console.error('------------- Windows "' + command + '" command failed, trying Unix... ---------------');

    }, function (command, args, env) {
        console.error('------------- Unix "' + command + '" command failed too. ---------------');
    });

android:drawableLeft margin and/or padding

textView.setCompoundDrawablesWithIntrinsicBounds(AppCompatResources.getDrawable(this,drawable),null,null,null);

addressTitleView.setCompoundDrawablePadding();

Fatal error: Call to a member function fetch_assoc() on a non-object

Please check if you have already close the database connection or not. In my case i was getting the error because the connection was close in upper line.

Iterating through a Collection, avoiding ConcurrentModificationException when removing objects in a loop

Make a copy of existing list and iterate over new copy.

for (String str : new ArrayList<String>(listOfStr))     
{
    listOfStr.remove(/* object reference or index */);
}

Spring configure @ResponseBody JSON format

Take a look at Rick Hightower's approach. His approach avoids configuring ObjectMapper as a singleton and allows you to filter the JSON response for the same object in different ways per each request method.

http://www.jroller.com/RickHigh/entry/filtering_json_feeds_from_spring

Fragment MyFragment not attached to Activity

simple solution and work 100%

if (getActivity() == null || !isAdded()) return;

How to decide when to use Node.js?

Node best for concurrent request handling -

So, Let’s start with a story. From last 2 years I am working on JavaScript and developing web front end and I am enjoying it. Back end guys provide’s us some API’s written in Java,python (we don’t care) and we simply write a AJAX call, get our data and guess what ! we are done. But in real it is not that easy, If data we are getting is not correct or there is some server error then we stuck and we have to contact our back end guys over the mail or chat(sometimes on whatsApp too :).) This is not cool. What if we wrote our API’s in JavaScript and call those API’s from our front end ? Yes that’s pretty cool because if we face any problem in API we can look into it. Guess what ! you can do this now , How ? – Node is there for you.

Ok agreed that you can write your API in JavaScript but what if I am ok with above problem. Do you have any other reason to use node for rest API ?

so here is the magic begins. Yes I do have other reasons to use node for our API’s.

Let’s go back to our traditional rest API system which is based on either blocking operation or threading. Suppose two concurrent request occurs( r1 and r2) , each of them require database operation. So In traditional system what will happens :

1. Waiting Way : Our server starts serving r1 request and waits for query response. after completion of r1 , server starts to serve r2 and does it in same way. So waiting is not a good idea because we don’t have that much time.

2. Threading Way : Our server will creates two threads for both requests r1 and r2 and serve their purpose after querying database so cool its fast.But it is memory consuming because you can see we started two threads also problem increases when both request is querying same data then you have to deal with deadlock kind of issues . So its better than waiting way but still issues are there.

Now here is , how node will do it:

3. Nodeway : When same concurrent request comes in node then it will register an event with its callback and move ahead it will not wait for query response for a particular request.So when r1 request comes then node’s event loop (yes there is an event loop in node which serves this purpose.) register an event with its callback function and move ahead for serving r2 request and similarly register its event with its callback. Whenever any query finishes it triggers its corresponding event and execute its callback to completion without being interrupted.

So no waiting, no threading , no memory consumption – yes this is nodeway for serving rest API.

Get Current date & time with [NSDate date]

NSLocale* currentLocale = [NSLocale currentLocale];
[[NSDate date] descriptionWithLocale:currentLocale];  

or use

NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init]; 
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
// or @"yyyy-MM-dd hh:mm:ss a" if you prefer the time with AM/PM 
NSLog(@"%@",[dateFormatter stringFromDate:[NSDate date]]);

Building a complete online payment gateway like Paypal

What you're talking about is becoming a payment service provider. I have been there and done that. It was a lot easier about 10 years ago than it is now, but if you have a phenomenal amount of time, money and patience available, it is still possible.

You will need to contact an acquiring bank. You didnt say what region of the world you are in, but by this I dont mean a local bank branch. Each major bank will generally have a separate card acquiring arm. So here in the UK we have (eg) Natwest bank, which uses Streamline (or Worldpay) as its acquiring arm. In total even though we have scores of major banks, they all end up using one of five or so card acquirers.

Happily, all UK card acquirers use a standard protocol for communication of authorisation requests, and end of day settlement. You will find minor quirks where some acquiring banks support some features and have slightly different syntax, but the differences are fairly minor. The UK standards are published by the Association for Payment Clearing Services (APACS) (which is now known as the UKPA). The standards are still commonly referred to as APACS 30 (authorization) and APACS 29 (settlement), but are now formally known as APACS 70 (books 1 through 7).

Although the APACS standard is widely supported across the UK (Amex and Discover accept messages in this format too) it is not used in other countries - each country has it's own - for example: Carte Bancaire in France, CartaSi in Italy, Sistema 4B in Spain, Dankort in Denmark etc. An effort is under way to unify the protocols across Europe - see EPAS.org

Communicating with the acquiring bank can be done a number of ways. Again though, it will depend on your region. In the UK (and most of Europe) we have one communications gateway that provides connectivity to all the major acquirers, they are called TNS and there are dozens of ways of communicating through them to the acquiring bank, from dialup 9600 baud modems, ISDN, HTTPS, VPN or dedicated line. Ultimately the authorisation request will be converted to X25 protocol, which is the protocol used by these acquiring banks when communicating with each other.

In summary then: it all depends on your region.

  • Contact a major bank and try to get through to their card acquiring arm.
  • Explain that you're setting up as a payment service provider, and request details on comms format for authorization requests and end of day settlement files
  • Set up a test merchant account and develop auth/settlement software and go through the accreditation process. Most acquirers help you through this process for free, but when you want to register as an accredited PSP some will request a fee.
  • you will need to comply with some regulations too, for example you may need to register as a payment institution

Once you are registered and accredited you'll then be able to accept customers and set up merchant accounts on behalf of the bank/s you're accredited against (bearing in mind that each acquirer will generally support multiple banks). Rinse and repeat with other acquirers as you see necessary.

Beyond that you have lots of other issues, mainly dealing with PCI-DSS. Thats a whole other topic and there are already some q&a's on this site regarding that. Like I say, its a phenomenal undertaking - most likely a multi-year project even for a reasonably sized team, but its certainly possible.

Expand and collapse with angular js

Here a simple and easy solution on Angular JS using ng-repeat that might help.

_x000D_
_x000D_
var app = angular.module('myapp', []);_x000D_
_x000D_
app.controller('MainCtrl', function($scope) {_x000D_
_x000D_
  $scope.arr= [_x000D_
    {name:"Head1",desc:"Head1Desc"},_x000D_
    {name:"Head2",desc:"Head2Desc"},_x000D_
    {name:"Head3",desc:"Head3Desc"},_x000D_
    {name:"Head4",desc:"Head4Desc"}_x000D_
    ];_x000D_
    _x000D_
    $scope.collapseIt = function(id){_x000D_
      $scope.collapseId = ($scope.collapseId==id)?-1:id;_x000D_
    }_x000D_
});
_x000D_
/* Put your css in here */_x000D_
li {_x000D_
  list-style:none;_x000D_
  padding:5px;_x000D_
  color:red;_x000D_
}_x000D_
div{_x000D_
  padding:10px;_x000D_
  background:#ddd;_x000D_
}
_x000D_
<!DOCTYPE html>_x000D_
<html ng-app="myapp">_x000D_
  <head>_x000D_
    <meta charset="utf-8" />_x000D_
    <title>AngularJS Simple Collapse</title>_x000D_
    <script data-require="[email protected]" src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.11/angular.min.js" data-semver="1.5.11"></script>_x000D_
</head>_x000D_
<body ng-controller="MainCtrl">_x000D_
<ul>_x000D_
  <li ng-repeat='ret in arr track by $index'>_x000D_
    <div ng-click="collapseIt($index)">{{ret.name}}</div>_x000D_
    <div ng-if="collapseId==$index">_x000D_
      {{ret.desc}}_x000D_
    </div>_x000D_
  </li>_x000D_
</ul>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

This should fulfill your requirements. Here is a working code.

Plunkr Link http://plnkr.co/edit/n5DZxluYHi8FI3OmzFq2?p=preview

Github: https://github.com/deepakkoirala/SimpleAngularCollapse

How to show changed file name only with git log?

Thanks for your answers, @mvp, @xero, I get what I want base on both of your answers.

git log --name-only 

or

git log --name-only --oneline

for short.

Redirecting to another page in ASP.NET MVC using JavaScript/jQuery

check the code below this will be helpful for you:

<script type="text/javascript">
  window.opener.location.href = '@Url.Action("Action", "EventstController")', window.close();
</script>

pip install - locale.Error: unsupported locale setting

Run the following command (it will work):

export LC_ALL="en_US.UTF-8"
export LC_CTYPE="en_US.UTF-8"
sudo dpkg-reconfigure locales

Register comdlg32.dll gets Regsvr32: DllRegisterServer entry point was not found

I also had the similar problem while registering myinfo.dll file in windows 7. Following work for me: Create a short cut on your desktop C:\Windows\System32\regsvr32.exe c:\windows\system32\myinfo.dll right click on the short cut just created and select as Run as administrator.

How to get week numbers from dates?

Actually, I think you may have discovered a bug in the week(...) function, or at least an error in the documentation. Hopefully someone will jump in and explain why I am wrong.

Looking at the code:

library(lubridate)
> week
function (x) 
yday(x)%/%7 + 1
<environment: namespace:lubridate>

The documentation states:

Weeks is the number of complete seven day periods that have occured between the date and January 1st, plus one.

But since Jan 1 is the first day of the year (not the zeroth), the first "week" will be a six day period. The code should (??) be

(yday(x)-1)%/%7 + 1

NB: You are using week(...) in the data.table package, which is the same code as lubridate::week except it coerces everything to integer rather than numeric for efficiency. So this function has the same problem (??).

Npm install failed with "cannot run in wd"

I fixed this by changing the ownership of /usr/local and ~/Users/user-name like so:

sudo chown -R my_name /usr/local

This allowed me to do everything without sudo

Programmatically navigate to another view controller/scene

let signUpVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "SignUp")
// self.present(signUpVC, animated: false, completion: nil)
self.navigationController?.pushViewController(signUpVC, animated: true)

Spool Command: Do not output SQL statement to file

Exec the query in TOAD or SQL DEVELOPER

---select /*csv*/ username, user_id, created from all_users;

Save in .SQL format in "C" drive

--- x.sql

execute command

---- set serveroutput on
     spool y.csv
     @c:\x.sql
     spool off;

How can I switch language in google play?

Answer below the dotted line below is the original that's now outdated.

Here is the latest information ( Thank you @deadfish ):

add &hl=<language> like &hl=pl or &hl=en

example: https://play.google.com/store/apps/details?id=com.example.xxx&hl=en or https://play.google.com/store/apps/details?id=com.example.xxx&hl=pl

All available languages and abbreviations can be looked up here: https://support.google.com/googleplay/android-developer/table/4419860?hl=en

......................................................................

To change the actual local market:

Basically the market is determined automatically based on your IP. You can change some local country settings from your Gmail account settings but still IP of the country you're browsing from is more important. To go around it you'd have to Proxy-cheat. Check out some ways/sites: http://www.affilorama.com/forum/market-research/how-to-change-country-search-settings-in-google-t4160.html

To do it from an Android phone you'd need to find an app. I don't have my Droid anymore but give this a try: http://forum.xda-developers.com/showthread.php?t=694720

How to do a case sensitive search in WHERE clause (I'm using SQL Server)?

USE BINARY_CHECKSUM

SELECT 
FROM Users
WHERE   
    BINARY_CHECKSUM(Username) = BINARY_CHECKSUM(@Username)
    AND BINARY_CHECKSUM(Password) = BINARY_CHECKSUM(@Password)

Local storage in Angular 2

As said above, should be: localStorageService.set('key', 'value'); and localStorageService.get('key');

Convert a Python list with strings all to lowercase or uppercase

If your purpose is to matching with another string by converting in one pass, you can use str.casefold() as well.

This is useful when you have non-ascii characters and matching with ascii versions(eg: maße vs masse).Though str.lower or str.upper fails in such cases, str.casefold() will pass. This is available in Python 3 and the idea is discussed in detail with the answer https://stackoverflow.com/a/31599276/4848659.

>>>str="Hello World";
>>>print(str.lower());
hello world
>>>print(str.upper());
HELLO WOLRD
>>>print(str.casefold());
hello world

PHP fwrite new line

fwrite($handle, "<br>"."\r\n");

Add this under

$password = $_POST['password'].PHP_EOL;

this. .

Can you change a path without reloading the controller in AngularJS?

Add following inside head tag

  <script type="text/javascript">
    angular.element(document.getElementsByTagName('head')).append(angular.element('<base href="' + window.location.pathname + '" />'));
  </script>

This will prevent the reload.

Convert file to byte array and vice versa

There is no such functionality but you can use a temporary file by File.createTempFile().

File temp = File.createTempFile(prefix, suffix);
// tell system to delete it when vm terminates.
temp.deleteOnExit();

WebDriver: check if an element exists?

This works for me every time:

    if(!driver.findElements(By.xpath("//*[@id='submit']")).isEmpty()){
        //THEN CLICK ON THE SUBMIT BUTTON
    }else{
        //DO SOMETHING ELSE AS SUBMIT BUTTON IS NOT THERE
    }

Image Greyscale with CSS & re-color on mouse-over?

There are numerous methods of accomplishing this, which I'll detail with a few examples below.

Pure CSS (using only one colored image)

img.grayscale {
  filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale"); /* Firefox 3.5+ */
  filter: gray; /* IE6-9 */
  -webkit-filter: grayscale(100%); /* Chrome 19+ & Safari 6+ */
}

img.grayscale:hover {
  filter: none;
  -webkit-filter: grayscale(0%);
}

_x000D_
_x000D_
img.grayscale {_x000D_
  filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale");_x000D_
  /* Firefox 3.5+, IE10 */_x000D_
  filter: gray;_x000D_
  /* IE6-9 */_x000D_
  -webkit-filter: grayscale(100%);_x000D_
  /* Chrome 19+ & Safari 6+ */_x000D_
  -webkit-transition: all .6s ease;_x000D_
  /* Fade to color for Chrome and Safari */_x000D_
  -webkit-backface-visibility: hidden;_x000D_
  /* Fix for transition flickering */_x000D_
}_x000D_
_x000D_
img.grayscale:hover {_x000D_
  filter: none;_x000D_
  -webkit-filter: grayscale(0%);_x000D_
}_x000D_
_x000D_
svg {_x000D_
  background: url(http://4.bp.blogspot.com/-IzPWLqY4gJ0/T01CPzNb1KI/AAAAAAAACgA/_8uyj68QhFE/s400/a2cf7051-5952-4b39-aca3-4481976cb242.jpg);_x000D_
}_x000D_
_x000D_
svg image {_x000D_
  transition: all .6s ease;_x000D_
}_x000D_
_x000D_
svg image:hover {_x000D_
  opacity: 0;_x000D_
}
_x000D_
<p>Firefox, Chrome, Safari, IE6-9</p>_x000D_
<img class="grayscale" src="http://4.bp.blogspot.com/-IzPWLqY4gJ0/T01CPzNb1KI/AAAAAAAACgA/_8uyj68QhFE/s1600/a2cf7051-5952-4b39-aca3-4481976cb242.jpg" width="400">_x000D_
<p>IE10 with inline SVG</p>_x000D_
<svg xmlns="http://www.w3.org/2000/svg" id="svgroot" viewBox="0 0 400 377" width="400" height="377">_x000D_
  <defs>_x000D_
     <filter id="filtersPicture">_x000D_
       <feComposite result="inputTo_38" in="SourceGraphic" in2="SourceGraphic" operator="arithmetic" k1="0" k2="1" k3="0" k4="0" />_x000D_
       <feColorMatrix id="filter_38" type="saturate" values="0" data-filterid="38" />_x000D_
    </filter>_x000D_
  </defs>_x000D_
  <image filter="url(&quot;#filtersPicture&quot;)" x="0" y="0" width="400" height="377" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://4.bp.blogspot.com/-IzPWLqY4gJ0/T01CPzNb1KI/AAAAAAAACgA/_8uyj68QhFE/s1600/a2cf7051-5952-4b39-aca3-4481976cb242.jpg" />_x000D_
   </svg>
_x000D_
_x000D_
_x000D_

You can find an article related to this technique here.

Pure CSS (using a grayscale and colored images)

This approach requires two copies of an image: one in grayscale and the other in full color. Using the CSS :hover psuedoselector, you can update the background of your element to toggle between the two:

#yourimage { 
    background: url(../grayscale-image.png);
}
#yourImage:hover { 
    background: url(../color-image.png};
}

_x000D_
_x000D_
#google {_x000D_
  background: url('http://www.google.com/logos/keystroke10-hp.png');_x000D_
  height: 95px;_x000D_
  width: 275px;_x000D_
  display: block;_x000D_
  /* Optional for a gradual animation effect */_x000D_
  transition: 0.5s;_x000D_
}_x000D_
_x000D_
#google:hover {_x000D_
  background: url('https://graphics217b.files.wordpress.com/2011/02/logo1w.png');_x000D_
}
_x000D_
<a id='google' href='http://www.google.com'></a>
_x000D_
_x000D_
_x000D_

This could also be accomplished by using a Javascript-based hover effect such as jQuery's hover() function in the same manner.

Consider a Third-Party Library

The desaturate library is a common library that allows you to easily switch between a grayscale version and full-colored version of a given element or image.

Javascript communication between browser tabs/windows

You can communicate between windows (tabbed or not) if they have a child-parent relationship.

Create and update a child window:

<html>
<head>
<title>Cross window test script</title>
<script>
var i = 0;
function open_and_run() {
    var w2 = window.open("", "winCounter"); 
    var myVar=setInterval(function(){myTimer(w2)},1000);
}

function myTimer(w2) {
    i++;
    w2.document.body.innerHTML="<center><h1>" + i + "</h1><p></center>";
}
</script>
</head>
<body>
Click to open a new window 
<button onclick="open_and_run();">Test This!</button>    
</body>
</html>

Child windows can use the parent object to communicate with the parent that spawned it, so you could control the music player from either window.

See it in action here: https://jsbin.com/cokipotajo/edit?html,js,output

make div's height expand with its content

I tried this and it worked

<div style=" position: absolute; direction: ltr;height:auto; min-height:100%">   </div>

How to load property file from classpath?

final Properties properties = new Properties();
try (final InputStream stream =
           this.getClass().getResourceAsStream("foo.properties")) {
    properties.load(stream);
    /* or properties.loadFromXML(...) */
}

Calling one Activity from another in Android

Very easiest way to call one activity to another is

startActivity( new Intent( getApplicationContext(), YourActivity.class ) );

Display Python datetime without time

You can usee the following code: week_start = str(datetime.today() - timedelta(days=datetime.today().weekday() % 7)).split(' ')[0]

What's the best way to do a backwards loop in C/C#/C++?

In C++ you basicially have the choice between iterating using iterators, or indices. Depending on whether you have a plain array, or a std::vector, you use different techniques.

Using std::vector

Using iterators

C++ allows you to do this using std::reverse_iterator:

for(std::vector<T>::reverse_iterator it = v.rbegin(); it != v.rend(); ++it) {
    /* std::cout << *it; ... */
}

Using indices

The unsigned integral type returned by std::vector<T>::size is not always std::size_t. It can be greater or less. This is crucial for the loop to work.

for(std::vector<int>::size_type i = someVector.size() - 1; 
    i != (std::vector<int>::size_type) -1; i--) {
    /* std::cout << someVector[i]; ... */
}

It works, since unsigned integral types values are defined by means of modulo their count of bits. Thus, if you are setting -N, you end up at (2 ^ BIT_SIZE) -N

Using Arrays

Using iterators

We are using std::reverse_iterator to do the iterating.

for(std::reverse_iterator<element_type*> it(a + sizeof a / sizeof *a), itb(a); 
    it != itb; 
    ++it) {
    /* std::cout << *it; .... */
}

Using indices

We can safely use std::size_t here, as opposed to above, since sizeof always returns std::size_t by definition.

for(std::size_t i = (sizeof a / sizeof *a) - 1; i != (std::size_t) -1; i--) {
   /* std::cout << a[i]; ... */
}

Avoiding pitfalls with sizeof applied to pointers

Actually the above way of determining the size of an array sucks. If a is actually a pointer instead of an array (which happens quite often, and beginners will confuse it), it will silently fail. A better way is to use the following, which will fail at compile time, if given a pointer:

template<typename T, std::size_t N> char (& array_size(T(&)[N]) )[N];

It works by getting the size of the passed array first, and then declaring to return a reference to an array of type char of the same size. char is defined to have sizeof of: 1. So the returned array will have a sizeof of: N * 1, which is what we are looking for, with only compile time evaluation and zero runtime overhead.

Instead of doing

(sizeof a / sizeof *a)

Change your code so that it now does

(sizeof array_size(a))

Error: 'int' object is not subscriptable - Python

What are you trying to do here: int([x[age1]])?? It makes no sense.

You just have to cast the age input as an int:

name1 = raw_input("What's your name? ")
age1 = raw_input ("how old are you? ")
twentyone = 21 - int(age1)
print "Hi, %s you will be 21 in: %d years." % (name1, twentyone)

Null check in VB

Change your Ands to AndAlsos

A standard And will test both expressions. If comp.Container is Nothing, then the second expression will raise a NullReferenceException because you're accessing a property on a null object.

AndAlso will short-circuit the logical evaluation. If comp.Container is Nothing, then the 2nd expression will not be evaluated.

How to hide Table Row Overflow?

Need to specify two attributes, table-layout:fixed on table and white-space:nowrap; on the cells. You also need to move the overflow:hidden; to the cells too

table { width:250px;table-layout:fixed; }
table tr { height:1em;  }
td { overflow:hidden;white-space:nowrap;  } 

Here's a Demo . Tested in Firefox 3.5.3 and IE 7

Connection failed: SQLState: '01000' SQL Server Error: 10061

  1. Windows firewall blocks the sql server. Even if you open the 1433 port from exceptions, in the client machine it sets the connection point to dynamic port. Add also the sql server to the exceptions.

"C:\Program Files\Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\Binn\Sqlservr.exe"

More info

  1. This page helped me to solve the problem. Especially

or if you feel brave, locate the alias in the registry and delete it there.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\ConnectTo\

Is there way to use two PHP versions in XAMPP?

I know this is the old post but I want to share there is library for still running mysql_connect() in PHP 7. It works by overriding the real function (mysql_connect() is overridden by mysqli_connect() which work on this library).

I found from this video https://www.youtube.com/watch?v=Eqd-jJu4sQ4

hopefully it helps

XML Error: There are multiple root elements

You need to enclose your <parent> elements in a surrounding element as XML Documents can have only one root node:

<parents> <!-- I've added this tag -->
    <parent>
        <child>
            Text
        </child>
    </parent>
    <parent>
        <child>
            <grandchild>
                Text
            </grandchild>
            <grandchild>
                Text
            </grandchild>
        </child>
        <child>
            Text
        </child>
    </parent>
</parents> <!-- I've added this tag -->

As you're receiving this markup from somewhere else, rather than generating it yourself, you may have to do this yourself by treating the response as a string and wrapping it with appropriate tags, prior to attempting to parse it as XML.

So, you've a couple of choices:

  1. Get the provider of the web service to return you actual XML that has one root node
  2. Pre-process the XML, as I've suggested above, to add a root node
  3. Pre-process the XML to split it into multiple chunks (i.e. one for each <parent> node) and process each as a distinct XML Document

How to create helper file full of functions in react native?

An alternative is to create a helper file where you have a const object with functions as properties of the object. This way you only export and import one object.

helpers.js

const helpers = {
    helper1: function(){

    },
    helper2: function(param1){

    },
    helper3: function(param1, param2){

    }
}

export default helpers;

Then, import like this:

import helpers from './helpers';

and use like this:

helpers.helper1();
helpers.helper2('value1');
helpers.helper3('value1', 'value2');

Calling javascript function in iframe

When you access resultFrame through document.all it only pulls it as an HTML element, not a window frame. You get the same issue if you have a frame fire an event using a "this" self-reference.

Replace:

document.all.resultFrame.Reset();

With:

window.frames.resultFrame.Reset();

Or:

document.all.resultFrame.contentWindow.Reset();

How to set css style to asp.net button?

I Found the coding...

 input[type="submit"]
    {
     //css coding
    }
 input[type="submit"]:Hover  
    {
     //css coding
    }

This is the solution for my issue..... Thanks everyone for the valuable answers.......

How to send objects through bundle

You can also make your objects Serializable and use the Bundle's getSerializable and putSerializable methods.

How to style a div to be a responsive square?

To achieve what you are looking for you can use the viewport-percentage length vw.

Here is a quick example I made on jsfiddle.

HTML:

<div class="square">
    <h1>This is a Square</h1>
</div>

CSS:

.square {
    background: #000;
    width: 50vw;
    height: 50vw;
}
.square h1 {
    color: #fff;
}

I am sure there are many other ways to do this but this way seemed the best to me.

Checking if a website is up via Python

Here's my solution using PycURL and validators

import pycurl, validators


def url_exists(url):
    """
    Check if the given URL really exists
    :param url: str
    :return: bool
    """
    if validators.url(url):
        c = pycurl.Curl()
        c.setopt(pycurl.NOBODY, True)
        c.setopt(pycurl.FOLLOWLOCATION, False)
        c.setopt(pycurl.CONNECTTIMEOUT, 10)
        c.setopt(pycurl.TIMEOUT, 10)
        c.setopt(pycurl.COOKIEFILE, '')
        c.setopt(pycurl.URL, url)
        try:
            c.perform()
            response_code = c.getinfo(pycurl.RESPONSE_CODE)
            c.close()
            return True if response_code < 400 else False
        except pycurl.error as err:
            errno, errstr = err
            raise OSError('An error occurred: {}'.format(errstr))
    else:
        raise ValueError('"{}" is not a valid url'.format(url))

Serialize an object to string

In some rare cases you might want to implement your own String serialization.

But that probably is a bad idea unless you know what you are doing. (e.g. serializing for I/O with a batch file)

Something like that would do the trick (and it would be easy to edit by hand/batch), but be careful that some more checks should be done, like that name doesn't contain a newline.

public string name {get;set;}
public int age {get;set;}

Person(string serializedPerson) 
{
    string[] tmpArray = serializedPerson.Split('\n');
    if(tmpArray.Length>2 && tmpArray[0].Equals("#")){
        this.name=tmpArray[1];
        this.age=int.TryParse(tmpArray[2]);
    }else{
        throw new ArgumentException("Not a valid serialization of a person");
    }
}

public string SerializeToString()
{
    return "#\n" +
           name + "\n" + 
           age;
}

PHP Converting Integer to Date, reverse of strtotime

I guess you are asking why is 1388516401 equal to 2014-01-01...?

There is an historical reason for that. There is a 32-bit integer variable, called time_t, that keeps the count of the time elapsed since 1970-01-01 00:00:00. Its value expresses time in seconds. This means that in 2014-01-01 00:00:01 time_t will be equal to 1388516401.

This leads us for sure to another interesting fact... In 2038-01-19 03:14:07 time_t will reach 2147485547, the maximum value for a 32-bit number. Ever heard about John Titor and the Year 2038 problem? :D

Dynamic button click event handler

@Debasish Sahu, your answer is an answer to another question, namely: how to know which button (or any other control) was clicked when there is a common handler for a couple of controls? So I'm giving an answer to this question how I usually do it, almost the same as yours, but note that also works without type conversion when it handles the same type of Controls:

Private Sub btn_done_clicked(ByVal sender As System.Object, ByVal e As System.EventArgs)
    Dim selectedBtn As Button = sender
    MsgBox("you have clicked button " & selectedBtn.Name)
End Sub

Postgres: INSERT if does not exist already

If you say that many of your rows are identical you will end checking many times. You can send them and the database will determine if insert it or not with the ON CONFLICT clause as follows

  INSERT INTO Hundred (name,name_slug,status) VALUES ("sql_string += hundred  
  +",'" + hundred_slug + "', " + status + ") ON CONFLICT ON CONSTRAINT
  hundred_pkey DO NOTHING;" cursor.execute(sql_string);

Run a batch file with Windows task scheduler

For those whose bat files are still not working in Windows 8+ Task Scheduler , one thing I would like to add to Ghazi's answer - after much suffering:

1) Under Actions, Choose "Create BASIC task", not "Create Task"

That did it for me, plus the other issues not to forget:

  1. Use the Start In path to your batch file, even though it says optional
  2. use quotes, if you need to, in your Start a program > program/script entry i.e "C:\my scripts\runme.bat" ...
  3. BUT DON'T use quotes in your Start in field. (Crazy but true!)

This worked without any need to trigger a command prompt.

(Sorry my rep is too low to add my Basic Task tip to Ghazi's comments)

Pythonic way to check if a list is sorted or not

A beautiful way to implement this is to use the imap function from itertools:

from itertools import imap, tee
import operator

def is_sorted(iterable, compare=operator.le):
  a, b = tee(iterable)
  next(b, None)
  return all(imap(compare, a, b))

This implementation is fast and works on any iterables.

The network adapter could not establish the connection - Oracle 11g

I had the similar issue. its resolved for me with a simple command.

lsnrctl start

The Network Adapter exception is caused because:

  1. The database host name or port number is wrong (OR)
  2. The database TNSListener has not been started. The TNSListener may be started with the lsnrctl utility.

Try to start the listener using the command prompt:

  1. Click Start, type cmd in the search field, and when cmd shows up in the list of options, right click it and select ‘Run as Administrator’.
  2. At the Command Prompt window, type lsnrctl start without the quotes and press Enter.
  3. Type Exit and press Enter.

Hope it helps.

Custom pagination view in Laravel 5

I use this code with k7 theme and use this code with their built in class. You can also use this code with your theme and your class as you need..

try to do this.

<section class="page-paging pt-0">
  <div class="container">
    <div class="row">
      <div class="col-12">
        <nav aria-label="Page navigation example">
          @if ($view_post->lastPage() > 1)
            <ul class="pager list-inline mb-0 text-center">
              <li class="{{ ($view_post->currentPage() == 1) ? ' disabled' : '' }}p-1 list-inline-item float-sm-left">
                <a class="active page-link brd-gray px-4 py-3 font-weight-bold" href="{{ $view_post->url(1) }}">
                  <i class="fa fa-angle-left pr-1"></i> Prev
                </a>
              </li>
              @for ($i = 1; $i <= $view_post->lastPage(); $i++)
              <li class=" p-1 list-inline-item d-none d-md-inline-block">
                <a class="{{ ($view_post->currentPage() == $i) ? ' active' : '' }} page-link brd-gray px-4 py-3 font-weight-bold" href="{{ $view_post->url($i) }}">{{ $i }}
                </a>
              </li>
              @endfor
              <li class="{{ ($view_post->currentPage() == $view_post->lastPage()) ? ' disabled' : '' }} p-1 list-inline-item float-sm-right">
                <a class="active page-link brd-gray px-4 py-3 font-weight-bold" href="{{ $view_post->url($view_post->currentPage()+1) }}"> Next 
                  <i class="fa fa-angle-right pl-1"></i>
                </a>
              </li>
            </ul>
          @endif
        </nav>
      </div>
    </div>
  </div>
</section>

How do I delete everything in Redis?

One more option from my side:

In our production and pre-production databases there are thousands of keys. Time to time we need to delete some keys (by some mask), modify by some criteria etc. Of course, there is no way to do it manually from CLI, especially having sharding (512 logical dbs in each physical).

For this purpose I write java client tool that does all this work. In case of keys deletion the utility can be very simple, only one class there:

public class DataCleaner {

    public static void main(String args[]) {
        String keyPattern = args[0];
        String host = args[1];
        int port = Integer.valueOf(args[2]);
        int dbIndex = Integer.valueOf(args[3]);

        Jedis jedis = new Jedis(host, port);

        int deletedKeysNumber = 0;
        if(dbIndex >= 0){
            deletedKeysNumber += deleteDataFromDB(jedis, keyPattern, dbIndex);
        } else {
            int dbSize = Integer.valueOf(jedis.configGet("databases").get(1));
            for(int i = 0; i < dbSize; i++){
                deletedKeysNumber += deleteDataFromDB(jedis, keyPattern, i);
            }
        }

        if(deletedKeysNumber == 0) {
            System.out.println("There is no keys with key pattern: " + keyPattern + " was found in database with host: " + host);
        }
    }

    private static int deleteDataFromDB(Jedis jedis, String keyPattern, int dbIndex) {
        jedis.select(dbIndex);
        Set<String> keys = jedis.keys(keyPattern);
        for(String key : keys){
            jedis.del(key);
            System.out.println("The key: " + key + " has been deleted from database index: " + dbIndex);
        }

        return keys.size();
    }

}

Writing such kind of tools I find very easy and spend no more then 5-10 min.

How to retrieve unique count of a field using Kibana + Elastic Search

For Kibana 4 go to this answer

This is easy to do with a terms panel:

Adding a terms panel to Kibana

If you want to select the count of distinct IP that are in your logs, you should specify in the field clientip, you should put a big enough number in length (otherwise, it will join different IP under the same group) and specify in the style table. After adding the panel, you will have a table with IP, and the count of that IP:

Table with IP and count

Eclipse reported "Failed to load JNI shared library"

First, ensure that your version of Eclipse and JDK match, either both 64-bit or both 32-bit (you can't mix-and-match 32-bit with 64-bit).

Second, the -vm argument in eclipse.ini should point to the java executable. See http://wiki.eclipse.org/Eclipse.ini for examples.

If you're unsure of what version (64-bit or 32-bit) of Eclipse you have installed, you can determine that a few different ways. See How to find out if an installed Eclipse is 32 or 64 bit version?

Data-frame Object has no Attribute

Check your DataFrame with data.columns

It should print something like this

Index([u'regiment', u'company',  u'name',u'postTestScore'], dtype='object')

Check for hidden white spaces..Then you can rename with

data = data.rename(columns={'Number ': 'Number'})

Set focus to field in dynamically loaded DIV

Dynamically added items have to be added to the DOM... clone().append() adds it to the DOM... which allows it to be selected via jquery.

How to recognize swipe in all 4 directions

I just felt like contributing this, looks more elegant in the end:

func addSwipe() {
    let directions: [UISwipeGestureRecognizerDirection] = [.Right, .Left, .Up, .Down]
    for direction in directions {
        let gesture = UISwipeGestureRecognizer(target: self, action: Selector("handleSwipe:"))
        gesture.direction = direction
        self.addGestureRecognizer(gesture)
    }
}

func handleSwipe(sender: UISwipeGestureRecognizer) {
    print(sender.direction)
}

Left Join With Where Clause

For this problem, as for many others involving non-trivial left joins such as left-joining on inner-joined tables, I find it convenient and somewhat more readable to split the query with a with clause. In your example,

with settings_for_char as (
  select setting_id, value from character_settings where character_id = 1
)
select
  settings.*,
  settings_for_char.value
from
  settings
  left join settings_for_char on settings_for_char.setting_id = settings.id;

Trust Anchor not found for Android SSL Connection

Replying to very old post. But maybe it will help some newbie and if non of the above works out.

Explanation: I know nobody wants explanation crap; rather the solution. But in one liner, you are trying to access a service from your local machine to a remote machine which does not trust your machine. You request need to gain the trust from remote server.

Solution: The following solution assumes that you have the following conditions met

  1. Trying to access a remote api from your local machine.
  2. You are building for Android app
  3. Your remote server is under proxy filtration (you use proxy in your browser setting to access the remote api service, typically a staging or dev server)
  4. You are testing on real device

Steps:

You need a .keystore extension file to signup your app. If you don't know how to create .keystore file; then follow along with the following section Create .keystore file or otherwise skip to next section Sign Apk File

Create .keystore file

Open Android Studio. Click top menu Build > Generate Signed APK. In the next window click the Create new... button. In the new window, please input in data in all fields. Remember the two Password field i recommend should have the same password; don't use different password; and also remember the save path at top most field Key store path:. After you input all the field click OK button.

Sign Apk File

Now you need to build a signed app with the .keystore file you just created. Follow these steps

  1. Build > Clean Project, wait till it finish cleaning
  2. Build > Generate Signed APK
  3. Click Choose existing... button
  4. Select the .keystore file we just created in the Create .keystore file section
  5. Enter the same password you created while creating in Create .keystore file section. Use same password for Key store password and Key password fields. Also enter the alias
  6. Click Next button
  7. In the next screen; which might be different based on your settings in build.gradle files, you need to select Build Types and Flavors.
  8. For the Build Types choose release from the dropdown
  9. For Flavors however it will depends on your settings in build.gradle file. Choose staging from this field. I used the following settings in the build.gradle, you can use the same as mine, but make sure you change the applicationId to your package name

    productFlavors {
        staging {
            applicationId "com.yourapplication.package"
            manifestPlaceholders = [icon: "@drawable/ic_launcher"]
            buildConfigField "boolean", "CATALYST_DEBUG", "true"
            buildConfigField "boolean", "ALLOW_INVALID_CERTIFICATE", "true"
        }
        production {
            buildConfigField "boolean", "CATALYST_DEBUG", "false"
            buildConfigField "boolean", "ALLOW_INVALID_CERTIFICATE", "false"
        }
    }
    
  10. Click the bottom two Signature Versions checkboxes and click Finish button.

Almost There:

All the hardwork is done, now the movement of truth. Inorder to access the Staging server backed-up by proxy, you need to make some setting in your real testing Android devices.

Proxy Setting in Android Device:

  1. Click the Setting inside Android phone and then wi-fi
  2. Long press on the connected wifi and select Modify network
  3. Click the Advanced options if you can't see the Proxy Hostname field
  4. In the Proxy Hostname enter the host IP or name you want to connect. A typical staging server will be named as stg.api.mygoodcompany.com
  5. For the port enter the four digit port number for example 9502
  6. Hit the Save button

One Last Stop:

Remember we generated the signed apk file in Sign APK File section. Now is the time to install that APK file.

  1. Open a terminal and changed to the signed apk file folder
  2. Connect your Android device to your machine
  3. Remove any previous installed apk file from the Android device
  4. Run adb install name of the apk file
  5. If for some reason the above command return with adb command not found. Enter the full path as C:\Users\shah\AppData\Local\Android\sdk\platform-tools\adb.exe install name of the apk file

I hope the problem might be solved. If not please leave me a comments.

Salam!

How to print without newline or space?

You will notice that all the above answers are correct. But I wanted to make a shortcut to always writing the " end='' " parameter in the end.

You could define a function like

def Print(*args,sep='',end='',file=None,flush=False):
    print(*args,sep=sep,end=end,file=file,flush=flush)

It would accept all the number of parameters. Even it will accept all the other parameters like file, flush ,etc and with the same name.

Is there a format code shortcut for Visual Studio?

To align the text in the proper format -

  • Ctrl + K + D for front end pages like .aspx or .cshtml

  • Ctrl + K + F for a .cs page

But observe to press all buttons in sequence...

What is the best open XML parser for C++?

How about RapidXML? RapidXML is a very fast and small XML DOM parser written in C++. It is aimed primarily at embedded environments, computer games, or any other applications where available memory or CPU processing power comes at a premium. RapidXML is licensed under Boost Software License and its source code is freely available.

Features

  • Parsing speed (including DOM tree building) approaching speed of strlen function executed on the same data.
  • On a modern CPU (as of 2008) the parser throughput is about 1 billion characters per second. See Performance section in the Online Manual.
  • Small memory footprint of the code and created DOM trees.
  • A headers-only implementation, simplifying the integration process.
  • Simple license that allows use for almost any purpose, both commercial and non-commercial, without any obligations.
  • Supports UTF-8 and partially UTF-16, UTF-32 encodings.
  • Portable source code with no dependencies other than a very small subset of C++ Standard Library.
  • This subset is so small that it can be easily emulated manually if use of standard library is undesired.

Limitations

  • The parser ignores DOCTYPE declarations.
  • There is no support for XML namespaces.
  • The parser does not check for character validity.
  • The interface of the parser does not conform to DOM specification.
  • The parser does not check for attribute uniqueness.

Source: wikipedia.org://Rapidxml


Depending on you use, you may use an XML Data Binding? CodeSynthesis XSD is an XML Data Binding compiler for C++ developed by Code Synthesis and dual-licensed under the GNU GPL and a proprietary license. Given an XML instance specification (XML Schema), it generates C++ classes that represent the given vocabulary as well as parsing and serialization code.

One of the unique features of CodeSynthesis XSD is its support for two different XML Schema to C++ mappings: in-memory C++/Tree and stream-oriented C++/Parser. The C++/Tree mapping is a traditional mapping with a tree-like, in-memory data structure. C++/Parser is a new, SAX-like mapping which represents the information stored in XML instance documents as a hierarchy of vocabulary-specific parsing events. In comparison to C++/Tree, the C++/Parser mapping allows one to handle large XML documents that would not fit in memory, perform stream-oriented processing, or use an existing in-memory representation.

Source: wikipedia.org://CodeSynthesis XSD

Convert string to symbol-able in ruby

from: http://ruby-doc.org/core/classes/String.html#M000809

str.intern => symbol
str.to_sym => symbol

Returns the Symbol corresponding to str, creating the symbol if it did not previously exist. See Symbol#id2name.

"Koala".intern         #=> :Koala
s = 'cat'.to_sym       #=> :cat
s == :cat              #=> true
s = '@cat'.to_sym      #=> :@cat
s == :@cat             #=> true

This can also be used to create symbols that cannot be represented using the :xxx notation.

'cat and dog'.to_sym   #=> :"cat and dog"

But for your example ...

"Book Author Title".gsub(/\s+/, "_").downcase.to_sym

should go ;)

Difference between "read commited" and "repeatable read"

My observation on initial accepted solution.

Under RR (default mysql) - If a tx is open and a SELECT has been fired, another tx can NOT delete any row belonging to previous READ result set until previous tx is committed (in fact delete statement in the new tx will just hang), however the next tx can delete all rows from the table without any trouble. Btw, a next READ in previous tx will still see the old data until it is committed.

java.io.FileNotFoundException: the system cannot find the file specified

Your file should directly be under the project folder, and not inside any other sub-folder.

If the folder of your project is named for e.g. AProject, it should be in the same place as your src folder.

Aproject
        src
        word.txt

SQL Views - no variables?

You are correct. Local variables are not allowed in a VIEW.

You can set a local variable in a table valued function, which returns a result set (like a view does.)

http://msdn.microsoft.com/en-us/library/ms191165.aspx

e.g.

CREATE FUNCTION dbo.udf_foo()
RETURNS @ret TABLE (col INT)
AS
BEGIN
  DECLARE @myvar INT;
  SELECT @myvar = 1;
  INSERT INTO @ret SELECT @myvar;
  RETURN;
END;
GO
SELECT * FROM dbo.udf_foo();
GO

How to publish a Web Service from Visual Studio into IIS?

If using Visual Studio 2010 you can right-click on the project for the service, and select properties. Then select the Web tab. Under the Servers section you can configure the URL. There is also a button to create the virtual directory.

BeanFactory vs ApplicationContext

For the most part, ApplicationContext is preferred unless you need to save resources, like on a mobile application.

I'm not sure about depending on XML format, but I'm pretty sure the most common implementations of ApplicationContext are the XML ones such as ClassPathXmlApplicationContext, XmlWebApplicationContext, and FileSystemXmlApplicationContext. Those are the only three I've ever used.

If your developing a web app, it's safe to say you'll need to use XmlWebApplicationContext.

If you want your beans to be aware of Spring, you can have them implement BeanFactoryAware and/or ApplicationContextAware for that, so you can use either BeanFactory or ApplicationContext and choose which interface to implement.

Remove elements from collection while iterating

Let me give a few examples with some alternatives to avoid a ConcurrentModificationException.

Suppose we have the following collection of books

List<Book> books = new ArrayList<Book>();
books.add(new Book(new ISBN("0-201-63361-2")));
books.add(new Book(new ISBN("0-201-63361-3")));
books.add(new Book(new ISBN("0-201-63361-4")));

Collect and Remove

The first technique consists in collecting all the objects that we want to delete (e.g. using an enhanced for loop) and after we finish iterating, we remove all found objects.

ISBN isbn = new ISBN("0-201-63361-2");
List<Book> found = new ArrayList<Book>();
for(Book book : books){
    if(book.getIsbn().equals(isbn)){
        found.add(book);
    }
}
books.removeAll(found);

This is supposing that the operation you want to do is "delete".

If you want to "add" this approach would also work, but I would assume you would iterate over a different collection to determine what elements you want to add to a second collection and then issue an addAll method at the end.

Using ListIterator

If you are working with lists, another technique consists in using a ListIterator which has support for removal and addition of items during the iteration itself.

ListIterator<Book> iter = books.listIterator();
while(iter.hasNext()){
    if(iter.next().getIsbn().equals(isbn)){
        iter.remove();
    }
}

Again, I used the "remove" method in the example above which is what your question seemed to imply, but you may also use its add method to add new elements during iteration.

Using JDK >= 8

For those working with Java 8 or superior versions, there are a couple of other techniques you could use to take advantage of it.

You could use the new removeIf method in the Collection base class:

ISBN other = new ISBN("0-201-63361-2");
books.removeIf(b -> b.getIsbn().equals(other));

Or use the new stream API:

ISBN other = new ISBN("0-201-63361-2");
List<Book> filtered = books.stream()
                           .filter(b -> b.getIsbn().equals(other))
                           .collect(Collectors.toList());

In this last case, to filter elements out of a collection, you reassign the original reference to the filtered collection (i.e. books = filtered) or used the filtered collection to removeAll the found elements from the original collection (i.e. books.removeAll(filtered)).

Use Sublist or Subset

There are other alternatives as well. If the list is sorted, and you want to remove consecutive elements you can create a sublist and then clear it:

books.subList(0,5).clear();

Since the sublist is backed by the original list this would be an efficient way of removing this subcollection of elements.

Something similar could be achieved with sorted sets using NavigableSet.subSet method, or any of the slicing methods offered there.

Considerations:

What method you use might depend on what you are intending to do

  • The collect and removeAl technique works with any Collection (Collection, List, Set, etc).
  • The ListIterator technique obviously only works with lists, provided that their given ListIterator implementation offers support for add and remove operations.
  • The Iterator approach would work with any type of collection, but it only supports remove operations.
  • With the ListIterator/Iterator approach the obvious advantage is not having to copy anything since we remove as we iterate. So, this is very efficient.
  • The JDK 8 streams example don't actually removed anything, but looked for the desired elements, and then we replaced the original collection reference with the new one, and let the old one be garbage collected. So, we iterate only once over the collection and that would be efficient.
  • In the collect and removeAll approach the disadvantage is that we have to iterate twice. First we iterate in the foor-loop looking for an object that matches our removal criteria, and once we have found it, we ask to remove it from the original collection, which would imply a second iteration work to look for this item in order to remove it.
  • I think it is worth mentioning that the remove method of the Iterator interface is marked as "optional" in Javadocs, which means that there could be Iterator implementations that throw UnsupportedOperationException if we invoke the remove method. As such, I'd say this approach is less safe than others if we cannot guarantee the iterator support for removal of elements.

How do I protect Python code?

I have looked at software protection in general for my own projects and the general philosophy is that complete protection is impossible. The only thing that you can hope to achieve is to add protection to a level that would cost your customer more to bypass than it would to purchase another license.

With that said I was just checking google for python obsfucation and not turning up a lot of anything. In a .Net solution, obsfucation would be a first approach to your problem on a windows platform, but I am not sure if anyone has solutions on Linux that work with Mono.

The next thing would be to write your code in a compiled language, or if you really want to go all the way, then in assembler. A stripped out executable would be a lot harder to decompile than an interpreted language.

It all comes down to tradeoffs. On one end you have ease of software development in python, in which it is also very hard to hide secrets. On the other end you have software written in assembler which is much harder to write, but is much easier to hide secrets.

Your boss has to choose a point somewhere along that continuum that supports his requirements. And then he has to give you the tools and time so you can build what he wants. However my bet is that he will object to real development costs versus potential monetary losses.

Fatal error: Call to a member function prepare() on null

In ---- model: Add use Jenssegers\Mongodb\Eloquent\Model as Eloquent;

Change the class ----- extends Model to class ----- extends Eloquent

How can I find a specific file from a Linux terminal?

Try this (via a shell):

update db
locate index.html

Or:

find /var -iname "index.html"

Replace /var with your best guess as to the directory it is in but avoid starting from /

how to rotate text left 90 degree and cell size is adjusted according to text in html

Unfortunately while I thought these answers may have worked for me, I struggled with a solution, as I'm using tables inside responsive tables - where the overflow-x is played with.

So, with that in mind, have a look at this link for a cleaner way, which doesn't have the weird width overflow issues. It worked for me in the end and was very easy to implement.

https://css-tricks.com/rotated-table-column-headers/

Using Java with Microsoft Visual Studio 2012

Java doesn't support the Net Framework. Java has its own Framework. Visual Studio used to support at one time J++ and J#, which were meant for Java developers who wanted to develop with the .Net, but since that has become extinct.

Most people when they want to develop java, they just go ahead and start with Netbeans, Eclipse, or something equivalent. They don't go around asking on sites like this if they could develop Java stuff in Visual Studio.

In my honest opinion, Java would not do very well in Visual Studio. Oracle and Microsoft are two separate entities and they need to remain that way. The only mix of Oracle and Microsoft I want to see is Java for Windows and Java development tools for Windows. I do not want to see Java in Visual Studio. It would get too confusing with C# lingering around the corner.

ASP.NET Identity reset password

In case of password reset, it is recommended to reset it through sending password reset token to registered user email and ask user to provide new password. If have created a easily usable .NET library over Identity framework with default configuration settins. You can find details at blog link and source code at github.

Working with SQL views in Entity Framework Core

Views are not currently supported by Entity Framework Core. See https://github.com/aspnet/EntityFramework/issues/827.

That said, you can trick EF into using a view by mapping your entity to the view as if it were a table. This approach comes with limitations. e.g. you can't use migrations, you need to manually specific a key for EF to use, and some queries may not work correctly. To get around this last part, you can write SQL queries by hand

context.Images.FromSql("SELECT * FROM dbo.ImageView")

How to clear/delete the contents of a Tkinter Text widget?

this works

import tkinter as tk
inputEdit.delete("1.0",tk.END)

Change the content of a div based on selection from dropdown menu

Meh too slow. Here's my example anyway :)
http://jsfiddle.net/cqDES/

$(function() {
    $('select').change(function() {
        var val = $(this).val();
        if (val) {
            $('div:not(#div' + val + ')').slideUp();
            $('#div' + val).slideDown();
        } else {
            $('div').slideDown();
        }
    });
});

Netbeans how to set command line arguments in Java

I am guessing that you are running the file using Run | Run File (or shift-F6) rather than Run | Run Main Project. The NetBeans 7.1 help file (F1 is your friend!) states for the Arguments parameter:

Add arguments to pass to the main class during application execution. Note that arguments cannot be passed to individual files.

I verified this with a little snippet of code:

public class Junk
{
    public static void main(String[] args)
    {
        for (String s : args)
            System.out.println("arg -> " + s);
    }
}

I set Run -> Arguments to x y z. When I ran the file by itself I got no output. When I ran the project the output was:

arg -> x
arg -> y
arg -> z

call javascript function onchange event of dropdown list

using jQuery

 $("#ddl").change(function () {
                alert($(this).val());
            });

jsFiddle

How to make primary key as autoincrement for Room Persistence lib

add @PrimaryKey(autoGenerate = true)

@Entity
public class User {

    @PrimaryKey(autoGenerate = true)
    private int id;

    @ColumnInfo(name = "full_name")
    private String name;

    @ColumnInfo(name = "phone")
    private String phone;

    public User(){
    }

    //type-1
    public User(String name, String phone) {
        this.name = name;
        this.phone = phone;
    }

    //type-2
    public User(int id, String name, String phone) {
        this.id = id;
        this.name = name;
        this.phone = phone;
    }

}

while storing data

 //type-1
 db.userDao().InsertAll(new User(sName,sPhone)); 

 //type-2
 db.userDao().InsertAll(new User(0,sName,sPhone)); 

type-1

If you are not passing value for primary key, by default it will 0 or null.

type-2

Put null or zero for the id while creating object (my case user object)

If the field type is long or int (or its TypeConverter converts it to a long or int), Insert methods treat 0 as not-set while inserting the item.

If the field's type is Integer or Long (Object) (or its TypeConverter converts it to an Integer or a Long), Insert methods treat null as not-set while inserting the item.

Sending command line arguments to npm script

For PowerShell users on Windows

The accepted answer did not work for me with npm 6.14. Neither adding no -- nor including it once does work. However, putting -- twice or putting "--" once before the arguments does the trick. Example:

npm run <my_script> -- -- <my arguments like --this>

Suspected reason

Like in bash, -- instructs PowerShell to treat all following arguments as literal strings, and not options (E.g see this answer). The issues seems to be that the command is interpreted one time more than expected, loosing the '--'. For instance, by doing

npm run <my_script> -- --option value

npm will run

<my_script> value

However, doing

npm run <my_script> "--" --option value

results in

<my_script> "--option" "value"

which works fine.

What is the difference between Bootstrap .container and .container-fluid classes?

You are right in 3.1 .container-fluid and .container are same and works like container but if you remove them it works like .container-fluid (full width). They had removed .container-fluid for "Mobile First Approach", but now it's back in 3.3.4 (and they will work differently)

To get latest bootstrap please read this post on stackoverflow it will help check it out.

How to properly create composite primary keys - MYSQL

I would not make the primary key of the "info" table a composite of the two values from other tables.

Others can articulate the reasons better, but it feels wrong to have a column that is really made up of two pieces of information. What if you want to sort on the ID from the second table for some reason? What if you want to count the number of times a value from either table is present?

I would always keep these as two distinct columns. You could use a two-column primay key in mysql ...PRIMARY KEY(id_a, id_b)... but I prefer using a two-column unique index, and having an auto-increment primary key field.

Get sum of MySQL column in PHP

$sql = "SELECT SUM(Value) FROM Codes";

$result = mysql_query($query);

while($row = mysql_fetch_array($result)){

    sum = $row['SUM(price)'];

}

echo sum;

How do I remove newlines from a text file?

To also remove the trailing newline at the end of the file

python -c "s=open('filename','r').read();open('filename', 'w').write(s.replace('\n',''))"

How does the stack work in assembly language?

The call stack is implemented by the x86 instruction set and the operating system.

Instructions like push and pop adjust the stack pointer while the operating system takes care of allocating memory as the stack grows for each thread.

The fact that the x86 stack "grows down" from higher to lower addresses make this architecture more susceptible to the buffer overflow attack.

Authenticating in PHP using LDAP through Active Directory

I like the Zend_Ldap Class, you can use only this class in your project, without the Zend Framework.

Using a scanner to accept String input and storing in a String Array

There is no use of pointers in java so far. You can create an object from the class and use different classes which are linked with each other and use the functions of every class in main class.

How do I remove a single file from the staging area (undo git add)?

You need to be in the directory of the file and then type the following into the terminal

git reset HEAD .

Assumption is that you need to reset one file only.

Java String.split() Regex

You could split on a word boundary with \b

Entity Framework Timeouts

If you are using DbContext and EF v6+, alternatively you can use:

this.context.Database.CommandTimeout = 180;

Div Scrollbar - Any way to style it?

Using javascript you can style the scroll bars. Which works fine in IE as well as FF.

Check the below links

From Twinhelix , Example 2 , Example 3 [or] you can find some 30 type of scroll style types by click the below link 30 scrolling techniques

NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder

Copy all order entries of home folder .iml file into your /src/main/main.iml file. This will solve the problem.

Debugging WebSocket in Google Chrome

Chrome developer tools allows to see handshake request which stays pending during the opened connection, but you can't see traffic as far as I know. However you can sniff it for example.

Cannot use mkdir in home directory: permission denied (Linux Lubuntu)

Try running fuser command

[root@guest2 ~]# fuser -mv /home

USER PID ACCESS COMMAND

/home: root 2919 f.... automount

[root@guest2 ~]# kill -9 2919

autofs service is known to cause this issue.

You can use command

#service autofs stop

And try again.

Sorting object property by values

a = { b: 1, p: 8, c: 2, g: 1 }
Object.keys(a)
  .sort((c,b) => {
    return a[b]-a[c]
  })
  .reduce((acc, cur) => {
    let o = {}
    o[cur] = a[cur]
    acc.push(o)
    return acc
   } , [])

output = [ { p: 8 }, { c: 2 }, { b: 1 }, { g: 1 } ]

Batch program to to check if process exists

That's why it's not working because you code something that is not right, that's why it always exit and the script executer will read it as not operable batch file that prevent it to exit and stop so it must be

tasklist /fi "IMAGENAME eq Notepad.exe" 2>NUL | find /I /N "Notepad.exe">NUL
if "%ERRORLEVEL%"=="0" (
msg * Program is running
goto Exit
)
else if "%ERRORLEVEL%"=="1" (
msg * Program is not running
goto Exit
)

rather than

@echo off
tasklist /fi "imagename eq notepad.exe" > nul
if errorlevel 1 taskkill /f /im "notepad.exe"
exit

jQuery send string as POST parameters

I was facing the problem in passing string value to string parameters in Ajax. After so much googling, i have come up with a custom solution as below.

var bar = 'xyz';
var calibri = 'no$libri';

$.ajax({
   type: "POST",
   dataType: "json",
   contentType: "application/json; charset=utf-8",
   url: "http://nakolesah.ru/",
   data: '{ foo: \'' + bar + '\', zoo: \'' + calibri + '\'}',
   success: function(msg){
       alert('wow'+msg);
   },
});

Here, bar and calibri are two string variables and you can pass whatever string value to respective string parameters in web method.

Intent.putExtra List

If you use ArrayList instead of list then also your problem wil be solved. In your code only modify List into ArrayList.

private List<Item> data;

Update UI from Thread in Android

As recommended by official documentation, you can use AsyncTask to handle work items shorter than 5ms in duration. If your task take more time, lookout for other alternatives.

HandlerThread is one alternative to Thread or AsyncTask. If you need to update UI from HandlerThread, post a message on UI Thread Looper and UI Thread Handler can handle UI updates.

Example code:

Android: Toast in a thread

How do I use TensorFlow GPU?

Follow the steps in the latest version of the documentation. Note: GPU and CPU functionality is now combined in a single tensorflow package

pip install tensorflow

# OLDER VERSIONS pip install tensorflow-gpu

https://www.tensorflow.org/install/gpu

This is a great guide for installing drivers and CUDA if needed: https://www.quantstart.com/articles/installing-tensorflow-22-on-ubuntu-1804-with-an-nvidia-gpu/

Validating with an XML schema in Python

There are two ways(actually there are more) that you could do this.
1. using lxml
pip install lxml

from lxml import etree, objectify
from lxml.etree import XMLSyntaxError

def xml_validator(some_xml_string, xsd_file='/path/to/my_schema_file.xsd'):
    try:
        schema = etree.XMLSchema(file=xsd_file)
        parser = objectify.makeparser(schema=schema)
        objectify.fromstring(some_xml_string, parser)
        print "YEAH!, my xml file has validated"
    except XMLSyntaxError:
        #handle exception here
        print "Oh NO!, my xml file does not validate"
        pass

xml_file = open('my_xml_file.xml', 'r')
xml_string = xml_file.read()
xml_file.close()

xml_validator(xml_string, '/path/to/my_schema_file.xsd')
  1. Use xmllint from the commandline. xmllint comes installed in many linux distributions.

>> xmllint --format --pretty 1 --load-trace --debug --schema /path/to/my_schema_file.xsd /path/to/my_xml_file.xml

Abstraction vs Encapsulation in Java

Abstraction is about identifying commonalities and reducing features that you have to work with at different levels of your code.

e.g. I may have a Vehicle class. A Car would derive from a Vehicle, as would a Motorbike. I can ask each Vehicle for the number of wheels, passengers etc. and that info has been abstracted and identified as common from Cars and Motorbikes.

In my code I can often just deal with Vehicles via common methods go(), stop() etc. When I add a new Vehicle type later (e.g. Scooter) the majority of my code would remain oblivious to this fact, and the implementation of Scooter alone worries about Scooter particularities.

Superscript in CSS only?

I was working on a page with the aim of having clearly legible text, with superscript elements NOT changing the line's top and bottom margins - with the following observations:

If for your main text you have line-height: 1.5em for example, you should reduce the line-height of your superscript text for it to appear correctly. I used line-height: 0.5em.

Also, vertical-align: super works well in most browsers but in IE8 when you have a superscript element present, the rest of that line is pushed down. So instead I used vertical-align: baseline together with a negative top and position: relative to achieve the same effect, which seems to work better across browsers.

So, to add to the "homegrown implementations":

.superscript {
    font-size: .83em;
    line-height: 0.5em;
    vertical-align: baseline;
    position: relative;
    top: -0.4em;
}

How do I stop a program when an exception is raised in Python?

You can stop catching the exception, or - if you need to catch it (to do some custom handling), you can re-raise:

try:
  doSomeEvilThing()
except Exception, e:
  handleException(e)
  raise

Note that typing raise without passing an exception object causes the original traceback to be preserved. Typically it is much better than raise e.

Of course - you can also explicitly call

import sys 
sys.exit(exitCodeYouFindAppropriate)

This causes SystemExit exception to be raised, and (unless you catch it somewhere) terminates your application with specified exit code.

How to capitalize the first character of each word in a string

Try this:

 private String capitalizer(String word){

        String[] words = word.split(" ");
        StringBuilder sb = new StringBuilder();
        if (words[0].length() > 0) {
            sb.append(Character.toUpperCase(words[0].charAt(0)) + words[0].subSequence(1, words[0].length()).toString().toLowerCase());
            for (int i = 1; i < words.length; i++) {
                sb.append(" ");
                sb.append(Character.toUpperCase(words[i].charAt(0)) + words[i].subSequence(1, words[i].length()).toString().toLowerCase());
            }
        }
        return  sb.toString();
    }

XmlSerializer giving FileNotFoundException at constructor

My solution is to go straight to reflection to create the serializer. This bypasses the strange file loading that causes the exception. I packaged this in a helper function that also takes care of caching the serializer.

private static readonly Dictionary<Type,XmlSerializer> _xmlSerializerCache = new Dictionary<Type, XmlSerializer>();

public static XmlSerializer CreateDefaultXmlSerializer(Type type) 
{
    XmlSerializer serializer;
    if (_xmlSerializerCache.TryGetValue(type, out serializer))
    {
        return serializer;
    }
    else
    {
        var importer = new XmlReflectionImporter();
        var mapping = importer.ImportTypeMapping(type, null, null);
        serializer = new XmlSerializer(mapping);
        return _xmlSerializerCache[type] = serializer;
    }
}

Load More Posts Ajax Button in WordPress

If I'm not using any category then how can I use this code? Actually, I want to use this code for custom post type.

Removing address bar from browser (to view on Android)

I found that if you add the command to unload, he keeps down the page, ie the page that move! Hope it works with you too!

window.addEventListener("load", function() { window.scrollTo(0, 1); });
window.addEventListener("unload", function() { window.scrollTo(0, 1); });

Using a 7-inch tablet with android, www.kupsoft.com visit my website and check how it behaves page, I use this command in my portal.

nodejs get file name from absolute path?

If you already know that the path separator is / (i.e. you are writing for a specific platform/environment), as implied by the example in your question, you could keep it simple and split the string by separator:

'/foo/bar/baz/asdf/quux.html'.split('/').pop()

That would be faster (and cleaner imo) than replacing by regular expression.

Again: Only do this if you're writing for a specific environment, otherwise use the path module, as paths are surprisingly complex. Windows, for instance, supports / in many cases but not for e.g. the \\?\? style prefixes used for shared network folders and the like. On Windows the above method is doomed to fail, sooner or later.

SQL - select distinct only on one column

You will use the following query:

SELECT * FROM [table] GROUP BY NUMBER;

Where [table] is the name of the table.

This provides a unique listing for the NUMBER column however the other columns may be meaningless depending on the vendor implementation; which is to say they may not together correspond to a specific row or rows.

Proper way to exit command line program?

if you do ctrl-z and then type exit it will close background applications.

Ctrl+Q is another good way to kill the application.

use "netsh wlan set hostednetwork ..." to create a wifi hotspot and the authentication can't work correctly

Use these commands on a windows command prompt(cmd) with administrator privilege (run as administrator):

netsh wlan set hostednetwork mode=allow ssid=tests key=tests123

netsh wlan start hostednetwork

Then you go to Network and sharing center and click on "change adapter settings" (I'm using windows 7, it can be a little different on windows 8)

Then right click on the lan connection (internet connection that you are using), properties.

Click on sharing tab, select the wireless connection tests (the name tests you can change on the command line) and check "Allow other network users to connect through this network connection"

This done, your connection is ready to use!

Multiple Inheritance in C#

I created a C# post-compiler that enables this kind of thing:

using NRoles;

public interface IFirst { void FirstMethod(); }
public interface ISecond { void SecondMethod(); }

public class RFirst : IFirst, Role {
  public void FirstMethod() { Console.WriteLine("First"); }
}

public class RSecond : ISecond, Role {
  public void SecondMethod() { Console.WriteLine("Second"); }
}

public class FirstAndSecond : Does<RFirst>, Does<RSecond> { }

You can run the post-compiler as a Visual Studio post-build-event:

C:\some_path\nroles-v0.1.0-bin\nutate.exe "$(TargetPath)"

In the same assembly you use it like this:

var fas = new FirstAndSecond();
fas.As<RFirst>().FirstMethod();
fas.As<RSecond>().SecondMethod();

In another assembly you use it like this:

var fas = new FirstAndSecond();
fas.FirstMethod();
fas.SecondMethod();

How do I push to GitHub under a different username?

If you use different windows user, your SSH key and git settings will be independent.

If this is not an option for you, then your friend should add your SSH key to her Github account.

Although, previous solution will keep you pushing as yourself, but it will allow you to push into her repo. If you don't want this and work in different folder on the same pc, you can setup username and email locally inside a folder with git by removing -g flag of the config command:

git config user.name her_username
git config user.email her_email

Alternatively, if you push over https protocol, Github will prompt for username/password every time (unless you use a password manager).

ASP.NET Web Site or ASP.NET Web Application?

One of the key differences is that Websites compile dynamically and create on-the-fly assemblies. Web applicaitons compile into one large assembly.

The distinction between the two has been done away with in Visual Studio 2008.

How to round the minute of a datetime object

This will get the 'floor' of a datetime object stored in tm rounded to the 10 minute mark before tm.

tm = tm - datetime.timedelta(minutes=tm.minute % 10,
                             seconds=tm.second,
                             microseconds=tm.microsecond)

If you want classic rounding to the nearest 10 minute mark, do this:

discard = datetime.timedelta(minutes=tm.minute % 10,
                             seconds=tm.second,
                             microseconds=tm.microsecond)
tm -= discard
if discard >= datetime.timedelta(minutes=5):
    tm += datetime.timedelta(minutes=10)

or this:

tm += datetime.timedelta(minutes=5)
tm -= datetime.timedelta(minutes=tm.minute % 10,
                         seconds=tm.second,
                         microseconds=tm.microsecond)

plot different color for different categorical levels using matplotlib

I usually do it using Seaborn which is built on top of matplotlib

import seaborn as sns
iris = sns.load_dataset('iris')
sns.scatterplot(x='sepal_length', y='sepal_width',
              hue='species', data=iris); 

Change GitHub Account username

Yes, it's possible. But first read, "What happens when I change my username?"

To change your username, click your profile picture in the top right corner, then click Settings. On the left side, click Account. Then click Change username.

HTML: How to make a submit button with text + image in it?

You're really close to the answer yourself

<button type="submit">
<img src="save.gif" alt="Save icon"/>
<br/>
Save
</button>

Or, you can just remove the type-attribute

<button>
<img src="save.gif" alt="Save icon"/>
<br/>
Save
</button>

Display Adobe pdf inside a div

You can use the Javascript library PDF.JS to display a PDF inside a div. The size of the PDF can be adjusted according to the size of the div. You can also setup event handlers for moving to next / previous pages of the PDF.

You can checkout PDF.JS Tutorial - How to display a PDF with Javascript to see how PDF.JS can be integrated in your HTML code.

Wpf control size to content?

If you are using the grid or alike component: In XAML, make sure that the elements in the grid have Grid.Row and Grid.Column defined, and ensure tha they don't have margins. If you used designer mode, or Expression Blend, it could have assigned margins relative to the whole grid instead of to particular cells. As for cell sizing, I add an extra cell that fills up the rest of the space:

    <Grid.RowDefinitions>
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>

Can I change the name of `nohup.out`?

my start.sh file:

#/bin/bash

nohup forever -c php artisan your:command >>storage/logs/yourcommand.log 2>&1 &

There is one important thing only. FIRST COMMAND MUST BE "nohup", second command must be "forever" and "-c" parameter is forever's param, "2>&1 &" area is for "nohup". After running this line then you can logout from your terminal, relogin and run "forever restartall" voilaa... You can restart and you can be sure that if script halts then forever will restart it.

I <3 forever

Flask Value error view function did not return a response

The following does not return a response:

You must return anything like return afunction() or return 'a string'.

This can solve the issue

Ruby: How to get the first character of a string

Because of an annoying design choice in Ruby before 1.9 — some_string[0] returns the character code of the first character — the most portable way to write this is some_string[0,1], which tells it to get a substring at index 0 that's 1 character long.

How to upgrade Python version to 3.7?

Try this if you are on ubuntu:

sudo apt-get update
sudo apt-get install build-essential libpq-dev libssl-dev openssl libffi-dev zlib1g-dev
sudo apt-get install python3-pip python3.7-dev
sudo apt-get install python3.7

In case you don't have the repository and so it fires a not-found package you first have to install this:

sudo apt-get install -y software-properties-common
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt-get update

more info here: http://devopspy.com/python/install-python-3-6-ubuntu-lts/

How to iterate over the file in python

The traceback indicates that probably you have an empty line at the end of the file. You can fix it like this:

f = open('test.txt','r')
g = open('test1.txt','w') 
while True:
    x = f.readline()
    x = x.rstrip()
    if not x: break
    print >> g, int(x, 16)

On the other hand it would be better to use for x in f instead of readline. Do not forget to close your files or better to use with that close them for you:

with open('test.txt','r') as f:
    with open('test1.txt','w') as g: 
        for x in f:
            x = x.rstrip()
            if not x: continue
            print >> g, int(x, 16)

Find an element in a list of tuples

If you just want the first number to match you can do it like this:

[item for item in a if item[0] == 1]

If you are just searching for tuples with 1 in them:

[item for item in a if 1 in item]

Constructor of an abstract class in C#

You can instantiate it after you implemented all the methods. Then the constructor will be called.

GIT fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree

I had same issue and I solved it by "pod setup" after installing cocoapods.

How do I set up a private Git repository on GitHub? Is it even possible?

Since January 7th, 2019, it is possible: unlimited free private repositories on GitHub!
... But for up to three collaborators per private repository.

Nat Friedman just announced it by twitter:

Today(!) we’re thrilled to announce unlimited free private repos for all GitHub users, and a new simplified Enterprise offering:

"New year, new GitHub: Announcing unlimited free private repos and unified Enterprise offering"

For the first time, developers can use GitHub for their private projects with up to three collaborators per repository for free.

Many developers want to use private repos to apply for a job, work on a side project, or try something out in private before releasing it publicly.
Starting today, those scenarios, and many more, are possible on GitHub at no cost.

Public repositories are still free (of course—no changes there) and include unlimited collaborators.

Replacing blank values (white space) with NaN in pandas

How about:

d = d.applymap(lambda x: np.nan if isinstance(x, basestring) and x.isspace() else x)

The applymap function applies a function to every cell of the dataframe.

Default password of mysql in ubuntu server 16.04

The only option that worked for me is the one described in this link.

In summary (in case the website goes down), it says:

To install MySQL:

sudo apt update
sudo apt install mysql-server

On the next prompt, you will be asked to set a password for the MySQL root user. Once you do that the script will also ask you to remove the anonymous user, restrict root user access to the local machine and remove the test database. You should answer “Y” (yes) to all questions.

sudo mysql_secure_installation

Then

sudo mysql

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'very_strong_password';
FLUSH PRIVILEGES;

After that you can exit:

exit

Now you can easily login with (Remember to type your very_strong_password):

mysql -u root -p
# type the password now.

This was the only option that worked for me after many hours trying the options above.

PHP XML how to output nice format

// ##### IN SUMMARY #####

$xmlFilepath = 'test.xml';
echoFormattedXML($xmlFilepath);

/*
 * echo xml in source format
 */
function echoFormattedXML($xmlFilepath) {
    header('Content-Type: text/xml'); // to show source, not execute the xml
    echo formatXML($xmlFilepath); // format the xml to make it readable
} // echoFormattedXML

/*
 * format xml so it can be easily read but will use more disk space
 */
function formatXML($xmlFilepath) {
    $loadxml = simplexml_load_file($xmlFilepath);

    $dom = new DOMDocument('1.0');
    $dom->preserveWhiteSpace = false;
    $dom->formatOutput = true;
    $dom->loadXML($loadxml->asXML());
    $formatxml = new SimpleXMLElement($dom->saveXML());
    //$formatxml->saveXML("testF.xml"); // save as file

    return $formatxml->saveXML();
} // formatXML

What Language is Used To Develop Using Unity

When you build for iPhone in Unity it does Ahead of Time (AOT) compilation of your mono assembly (written in C# or JavaScript) to native ARM code.

The authoring tool also creates a stub xcode project and references that compiled lib. You can add objective C code to this xcode project if there is native stuff you want to do that isn't exposed in Unity's environment yet (e.g. accessing the compass and/or gyroscope).

Copying PostgreSQL database to another server

Run this command with database name, you want to backup, to take dump of DB.

 pg_dump -U {user-name} {source_db} -f {dumpfilename.sql}

 eg. pg_dump -U postgres mydbname -f mydbnamedump.sql

Now scp this dump file to remote machine where you want to copy DB.

eg. scp mydbnamedump.sql user01@remotemachineip:~/some/folder/

On remote machine run following command in ~/some/folder to restore the DB.

 psql -U {user-name} -d {desintation_db}-f {dumpfilename.sql}

 eg. psql -U postgres -d mynewdb -f mydbnamedump.sql

How to convert string date to Timestamp in java?

Use below code to convert String Date to Epoc Timestamp. Note : - Your input Date format should match with SimpleDateFormat.

String inputDateInString= "8/15/2017 12:00:00 AM";
SimpleDateFormat dateFormat = new SimpleDateFormat("MM/dd/yyy hh:mm:ss");

Date parsedDate = dateFormat.parse("inputDateInString");

Timestamp timestamp = new java.sql.Timestamp(parsedDate.getTime());

System.out.println("Timestamp "+ timestamp.getTime());

moving committed (but not pushed) changes to a new branch after pull

If you have a low # of commits and you don't care if these are combined into one mega-commit, this works well and isn't as scary as doing git rebase:

unstage the files (replace 1 with # of commits)

git reset --soft HEAD~1

create a new branch

git checkout -b NewBranchName

add the changes

git add -A

make a commit

git commit -m "Whatever"

Inserting image into IPython notebook markdown

I am using ipython 2.0, so just two line.

from IPython.display import Image
Image(filename='output1.png')

UICollectionView current visible cell index

Swift 3 & Swift 4:

func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
   var visibleRect = CGRect()

   visibleRect.origin = collectionView.contentOffset
   visibleRect.size = collectionView.bounds.size

   let visiblePoint = CGPoint(x: visibleRect.midX, y: visibleRect.midY)

   guard let indexPath = collectionView.indexPathForItem(at: visiblePoint) else { return } 

   print(indexPath[1])
}

If you want to show actual number than you can add +1

Difference between if () { } and if () : endif;

I feel that none of the preexisting answers fully identify the answer here, so I'm going to articulate my own perspective. Functionally, the two methods are the same. If the programer is familiar with other languages following C syntax, then they will likely feel more comfortable with the braces, or else if php is the first language that they're learning, they will feel more comfortable with the if endif syntax, since it seems closer to regular language.

If you're a really serious programmer and need to get things done fast, then I do believe that the curly brace syntax is superior because it saves time typing

if(/*condition*/){
    /*body*/ 
}

compared to

if(/*condition*/):
    /*body*/
endif;

This is especially true with other loops, say, a foreach where you would end up typing an extra 10 chars. With braces, you just need to type two characters, but for the keyword based syntax you have to type a whole extra keyword for every loop and conditional statement.

JUnit Testing private variables?

Yeah you can use reflections to access private variables. Altough not a good idea.

Check this out:

http://en.wikibooks.org/wiki/Java_Programming/Reflection/Accessing_Private_Features_with_Reflection

What is the difference between Task.Run() and Task.Factory.StartNew()

The second method, Task.Run, has been introduced in a later version of the .NET framework (in .NET 4.5).

However, the first method, Task.Factory.StartNew, gives you the opportunity to define a lot of useful things about the thread you want to create, while Task.Run doesn't provide this.

For instance, lets say that you want to create a long running task thread. If a thread of the thread pool is going to be used for this task, then this could be considered an abuse of the thread pool.

One thing you could do in order to avoid this would be to run the task in a separate thread. A newly created thread that would be dedicated to this task and would be destroyed once your task would have been completed. You cannot achieve this with the Task.Run, while you can do so with the Task.Factory.StartNew, like below:

Task.Factory.StartNew(..., TaskCreationOptions.LongRunning);

As it is stated here:

So, in the .NET Framework 4.5 Developer Preview, we’ve introduced the new Task.Run method. This in no way obsoletes Task.Factory.StartNew, but rather should simply be thought of as a quick way to use Task.Factory.StartNew without needing to specify a bunch of parameters. It’s a shortcut. In fact, Task.Run is actually implemented in terms of the same logic used for Task.Factory.StartNew, just passing in some default parameters. When you pass an Action to Task.Run:

Task.Run(someAction);

that’s exactly equivalent to:

Task.Factory.StartNew(someAction, 
    CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default);

Calling a parent window function from an iframe

Another addition for those who need it. Ash Clarke's solution does not work if they are using different protocols so be sure that if you are using SSL, your iframe is using SSL as well or it will break the function. His solution did work for the domains itself though, so thanks for that.

How to save the contents of a div as a image?

There are several of this same question (1, 2). One way of doing it is using canvas. Here's a working solution. Here you can see some working examples of using this library.

Textarea to resize based on content length

You may also try contenteditable attribute onto a normal p or div. Not really a textarea but it will auto-resize without script.

_x000D_
_x000D_
.divtext {
    border: ridge 2px;
    padding: 5px;
    width: 20em;
    min-height: 5em;
    overflow: auto;
}
_x000D_
<div class="divtext" contentEditable>Hello World</div>
_x000D_
_x000D_
_x000D_

The first day of the current month in php using date_modify as DateTime object

Requires PHP 5.3 to work ("first day of" is introduced in PHP 5.3). Otherwise the example above is the only way to do it:

<?php
    // First day of this month
    $d = new DateTime('first day of this month');
    echo $d->format('jS, F Y');

    // First day of a specific month
    $d = new DateTime('2010-01-19');
    $d->modify('first day of this month');
    echo $d->format('jS, F Y');

    // alternatively...
    echo date_create('2010-01-19')
      ->modify('first day of this month')
      ->format('jS, F Y');

In PHP 5.4+ you can do this:

<?php
    // First day of this month
    echo (new DateTime('first day of this month'))->format('jS, F Y');

    echo (new DateTime('2010-01-19'))
      ->modify('first day of this month')
      ->format('jS, F Y');

If you prefer a concise way to do this, and already have the year and month in numerical values, you can use date():

<?php
    echo date('Y-m-01'); // first day of this month
    echo date("$year-$month-01"); // first day of a month chosen by you

Hibernate SessionFactory vs. JPA EntityManagerFactory

Prefer EntityManagerFactory and EntityManager. They are defined by the JPA standard.

SessionFactory and Session are hibernate-specific. The EntityManager invokes the hibernate session under the hood. And if you need some specific features that are not available in the EntityManager, you can obtain the session by calling:

Session session = entityManager.unwrap(Session.class);

How can I render repeating React elements?

In the spirit of functional programming, let's make our components a bit easier to work with by using abstractions.

// converts components into mappable functions
var mappable = function(component){
  return function(x, i){
    return component({key: i}, x);
  }
}

// maps on 2-dimensional arrays
var map2d = function(m1, m2, xss){
  return xss.map(function(xs, i, arr){
    return m1(xs.map(m2), i, arr);
  });
}

var td = mappable(React.DOM.td);
var tr = mappable(React.DOM.tr);
var th = mappable(React.DOM.th);

Now we can define our render like this:

render: function(){
  return (
    <table>
      <thead>{this.props.titles.map(th)}</thead>
      <tbody>{map2d(tr, td, this.props.rows)}</tbody>
    </table>
  );
}

jsbin


An alternative to our map2d would be a curried map function, but people tend to shy away from currying.

What is the correct way to start a mongod service on linux / OS X?

After installing mongodb through brew, run this to get it up and running:

mongod --dbpath /usr/local/var/mongodb

How to display HTML tags as plain text

As many others have said, htmlentities() will do the trick... but it will look like shit.

Wrap it up with a <pre> tag and you'll preserve your indentation.

echo '<pre>';
echo htmlspecialchars($YOUR_HTML);
echo '</pre>';

How can I define colors as variables in CSS?

dicejs.com (formally cssobjs) is a client-side version of SASS. You can set variables in your CSS (stored in json formatted CSS) and re-use your color variables.

//create the CSS JSON object with variables and styles
var myCSSObjs = {
  cssVariables : {
    primaryColor:'#FF0000',
    padSmall:'5px',
    padLarge:'$expr($padSmall * 2)'
  }
  'body' : {padding:'$padLarge'},
  'h1' : {margin:'0', padding:'0 0 $padSmall 0'},
  '.pretty' : {padding:'$padSmall', margin:'$padSmall', color:'$primaryColor'}
};

//give your css objects a name and inject them
$.cssObjs('myStyles',myCSSObjs).injectStyles();

And here is a link to a complete downloadable demo which is a little more helpful then their documentation : dicejs demo

How to check command line parameter in ".bat" file?

I've been struggling recently with the implementation of complex parameter switches in a batch file so here is the result of my research. None of the provided answers are fully safe, examples:

"%1"=="-?" will not match if the parameter is enclosed in quotes (needed for file names etc.) or will crash if the parameter is in quotes and has spaces (again often seen in file names)

@ECHO OFF
SETLOCAL
echo.
echo starting parameter test...
echo.
rem echo First parameter is %1
if "%1"=="-?" (echo Condition is true, param=%1) else (echo Condition is false, param=%1)
C:\>test.bat -?

starting parameter test...

Condition is true, param=-?

C:\>test.bat "-?"

starting parameter test...

Condition is false, param="-?"

Any combination with square brackets [%1]==[-?] or [%~1]==[-?] will fail in case the parameter has spaces within quotes:

@ECHO OFF
SETLOCAL 
echo.
echo starting parameter test...
echo.
echo First parameter is %1
if [%~1]==[-?] (echo Condition is true, param=%1) else (echo Condition is false, param=%1)

C:\>test.bat "long file name"

starting parameter test...

First parameter is "long file name"
file was unexpected at this time.

The proposed safest solution "%~1"=="-?" will crash with a complex parameter that includes text outside the quotes and text with spaces within the quotes:

@ECHO OFF
SETLOCAL 
echo.
echo starting parameter test...
echo.
echo First parameter is %1
if "%~1"=="-?" (echo Condition is true, param=%1) else (echo Condition is false, param=%1)

C:\>test.bat -source:"long file name"

starting parameter test...

First parameter is -source:"long file name"
file was unexpected at this time.

The only way to ensure all above scenarios are covered is to use EnableDelayedExpansion and to pass the parameters by reference (not by value) using variables. Then even the most complex scenario will work fine:

@ECHO OFF
SETLOCAL EnableDelayedExpansion
echo.
echo starting parameter test...
echo.
echo First parameter is %1
:: we assign the parameter to a variable to pass by reference with delayed expansion
set "var1=%~1"
echo var1 is !var1!
:: we assign the value to compare with to a second variable to pass by reference with delayed expansion
set "var2=-source:"c:\app images"\image.png"
echo var2 is !var2!
if "!var1!"=="!var2!" (echo Condition is true, param=!var1!) else (echo Condition is false, param=!var1!)
C:\>test.bat -source:"c:\app images"\image.png

starting parameter test...

First parameter is -source:"c:\app images"\image.png
var1 is -source:"c:\app images"\image.png
var2 is -source:"c:\app images"\image.png
Condition is true, param=-source:"c:\app images"\image.png

C:\>test.bat -source:"c:\app images"\image1.png

starting parameter test...

First parameter is -source:"c:\app images"\image1.png
var1 is -source:"c:\app images"\image1.png
var2 is -source:"c:\app images"\image.png
Condition is false, param=-source:"c:\app images"\image1.png

C:\>test.bat -source:"c:\app images\image.png"

starting parameter test...

First parameter is -source:"c:\app images\image.png"
var1 is -source:"c:\app images\image.png"
var2 is -source:"c:\app images"\image.png
Condition is false, param=-source:"c:\app images\image.png"

how to make UITextView height dynamic according to text length?

Swift 4+

This is extremely easy with autolayout! I'll explain the most simple use case. Let's say there is only a UITextView in your UITableViewCell.

  • Fit the textView to the contentView with constraints.
  • Disable scrolling for the textView.
  • Update the tableView on textViewDidChange.

That's all!

protocol TextViewUpdateProtocol {
    func textViewChanged()
}

class TextViewCell: UITableViewCell {
    
    //MARK: Reuse ID
    static let identifier = debugDescription()
    
    //MARK: UI Element(s)
    /// Reference of the parent table view so that it can be updated
    var textViewUpdateDelegate: TextViewUpdateProtocol!
    
    lazy var textView: UITextView = {
        let textView = UITextView()
        textView.isScrollEnabled = false
        textView.delegate = self
        textView.layer.borderColor = UIColor.lightGray.cgColor
        textView.layer.borderWidth = 1
        textView.translatesAutoresizingMaskIntoConstraints = false
        return textView
    }()
    
    //MARK: Padding Variable(s)
    let padding: CGFloat = 50
    
    //MARK: Initializer(s)
    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        
        addSubviews()
        addConstraints()
        
        textView.becomeFirstResponder()
    }
    
    //MARK: Helper Method(s)
    func addSubviews() {
        contentView.addSubview(textView)
    }
    
    func addConstraints() {
        textView.leadingAnchor  .constraint(equalTo: contentView.leadingAnchor, constant: padding).isActive = true
        textView.trailingAnchor .constraint(equalTo: contentView.trailingAnchor, constant: -padding).isActive = true
        textView.topAnchor      .constraint(equalTo: contentView.topAnchor, constant: padding).isActive = true
        textView.bottomAnchor   .constraint(equalTo: contentView.bottomAnchor, constant: -padding).isActive = true
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
}

extension TextViewCell: UITextViewDelegate {
    
    func textViewDidChange(_ textView: UITextView) {
        textViewUpdateDelegate.textViewChanged()
    }
    
}

Now you have to inherit implement the protocol in your ViewController.

extension ViewController: TextViewUpdateProtocol {
    
    func textViewChanged() {
        tableView.beginUpdates()
        tableView.endUpdates()
    }
    
}

Check out my repo for the full implementation.

how to display a div triggered by onclick event

You'll have to give an ID to the div you want to show/hide, then use this code:

html:

<div id="one">
    <div id="tow">
        This is text
    </div>
    <button onclick="javascript:showDiv();">Click to show div</button>
</div>

javascript:

function showDiv() {
    div = document.getElementById('tow');
    div.style.display = "block";
}

CSS:

?#tow { display: none; }?

Fiddle: http://jsfiddle.net/xkdNa/

How to switch activity without animation in Android?

You can also just do this in all the activities that you dont want to transition from:

@Override
public void onPause() {
    super.onPause();
    overridePendingTransition(0, 0);
}

I like this approach because you do not have to mess with the style of your activity.

Adb Devices can't find my phone

I have a ZTE Crescent phone (Orange San Francisco II).

When I connect the phone to the USB a disk shows up in OS X named 'ZTE_USB_Driver'.

Running adb devices displays no connected devices. But after I eject the 'ZTE_USB_Driver' disk from OS X, and run adb devices again the phone shows up as connected.

What is the boundary in multipart/form-data?

Is the ??? free to be defined by the user?

Yes.

or is it supplied by the HTML?

No. HTML has nothing to do with that. Read below.

Is it possible for me to define the ??? as abcdefg?

Yes.

If you want to send the following data to the web server:

name = John
age = 12

using application/x-www-form-urlencoded would be like this:

name=John&age=12

As you can see, the server knows that parameters are separated by an ampersand &. If & is required for a parameter value then it must be encoded.

So how does the server know where a parameter value starts and ends when it receives an HTTP request using multipart/form-data?

Using the boundary, similar to &.

For example:

--XXX
Content-Disposition: form-data; name="name"

John
--XXX
Content-Disposition: form-data; name="age"

12
--XXX--

In that case, the boundary value is XXX. You specify it in the Content-Type header so that the server knows how to split the data it receives.

So you need to:

  • Use a value that won't appear in the HTTP data sent to the server.

  • Be consistent and use the same value everywhere in the request message.

How to make a Java thread wait for another thread's output?

You could read from a blocking queue in one thread and write to it in another thread.

Check if two unordered lists are equal

One liner answer to the above question is :-

let the two lists be list1 and list2, and your requirement is to ensure whether two lists have the same elements, then as per me, following will be the best approach :-

if ((len(list1) == len(list2)) and
   (all(i in list2 for i in list1))):
    print 'True'
else:
    print 'False'

The above piece of code will work per your need i.e. whether all the elements of list1 are in list2 and vice-verse.

But if you want to just check whether all elements of list1 are present in list2 or not, then you need to use the below code piece only :-

if all(i in list2 for i in list1):
    print 'True'
else:
    print 'False'

The difference is, the later will print True, if list2 contains some extra elements along with all the elements of list1. In simple words, it will ensure that all the elements of list1 should be present in list2, regardless of whether list2 has some extra elements or not.

How to Sort a List<T> by a property in the object

Using LINQ

objListOrder = GetOrderList()
                   .OrderBy(o => o.OrderDate)
                   .ToList();

objListOrder = GetOrderList()
                   .OrderBy(o => o.OrderId)
                   .ToList();

How to return a string value from a Bash function

All answers above ignore what has been stated in the man page of bash.

  • All variables declared inside a function will be shared with the calling environment.
  • All variables declared local will not be shared.

Example code

#!/bin/bash

f()
{
    echo function starts
    local WillNotExists="It still does!"
    DoesNotExists="It still does!"
    echo function ends
}

echo $DoesNotExists #Should print empty line
echo $WillNotExists #Should print empty line
f                   #Call the function
echo $DoesNotExists #Should print It still does!
echo $WillNotExists #Should print empty line

And output

$ sh -x ./x.sh
+ echo

+ echo

+ f
+ echo function starts 
function starts
+ local 'WillNotExists=It still does!'
+ DoesNotExists='It still does!'
+ echo function ends 
function ends
+ echo It still 'does!' 
It still does!
+ echo

Also under pdksh and ksh this script does the same!

Regular expression: zero or more occurrences of optional character /

/*

If your delimiters are slash-based, escape it:

\/*

* means "0 or more of the previous repeatable pattern", which can be a single character, a character class or a group.

type checking in javascript

A variable will never be an integer type in JavaScript — it doesn't distinguish between different types of Number.

You can test if the variable contains a number, and if that number is an integer.

(typeof foo === "number") && Math.floor(foo) === foo

If the variable might be a string containing an integer and you want to see if that is the case:

foo == parseInt(foo, 10)

Embedding DLLs in a compiled executable

Neither the ILMerge approach nor Lars Holm Jensen's handling the AssemblyResolve event will work for a plugin host. Say executable H loads assembly P dynamically and accesses it via interface IP defined in an separate assembly. To embed IP into H one shall need a little modification to Lars's code:

Dictionary<string, Assembly> loaded = new Dictionary<string,Assembly>();
AppDomain.CurrentDomain.AssemblyResolve += (sender, args) =>
{   Assembly resAssembly;
    string dllName = args.Name.Contains(",") ? args.Name.Substring(0, args.Name.IndexOf(',')) : args.Name.Replace(".dll","");
    dllName = dllName.Replace(".", "_");
    if ( !loaded.ContainsKey( dllName ) )
    {   if (dllName.EndsWith("_resources")) return null;
        System.Resources.ResourceManager rm = new System.Resources.ResourceManager(GetType().Namespace + ".Properties.Resources", System.Reflection.Assembly.GetExecutingAssembly());
        byte[] bytes = (byte[])rm.GetObject(dllName);
        resAssembly = System.Reflection.Assembly.Load(bytes);
        loaded.Add(dllName, resAssembly);
    }
    else
    {   resAssembly = loaded[dllName];  }
    return resAssembly;
};  

The trick to handle repeated attempts to resolve the same assembly and return the existing one instead of creating a new instance.

EDIT: Lest it spoil .NET's serialization, make sure to return null for all assemblies not embedded in yours, thereby defaulting to the standard behaviour. You can get a list of these libraries by:

static HashSet<string> IncludedAssemblies = new HashSet<string>();
string[] resources = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceNames();
for(int i = 0; i < resources.Length; i++)
{   IncludedAssemblies.Add(resources[i]);  }

and just return null if the passed assembly does not belong to IncludedAssemblies .

Parse time of format hh:mm:ss

String time = "12:32:22";
String[] values = time.split(":");

This will take your time and split it where it sees a colon and put the value in an array, so you should have 3 values after this.

Then loop through string array and convert each one. (with Integer.parseInt)

How do I update Node.js?

You may use Chocolatey on Windows. It's very easy to use and useful for keeping you updated with other applications too.

Also, you can just simply download the latest version from https://nodejs.org and install it.

Better way to check if a Path is a File or a Directory?

After combining the suggestions from the other answers, I realized I came up with about the same thing as Ronnie Overby's answer. Here are some tests to point out some things to think about:

  1. folders can have "extensions": C:\Temp\folder_with.dot
  2. files cannot end with a directory separator (slash)
  3. There are technically two directory separators which are platform specific -- i.e. may or may not be slashes (Path.DirectorySeparatorChar and Path.AltDirectorySeparatorChar)

Tests (Linqpad)

var paths = new[] {
    // exists
    @"C:\Temp\dir_test\folder_is_a_dir",
    @"C:\Temp\dir_test\is_a_dir_trailing_slash\",
    @"C:\Temp\dir_test\existing_folder_with.ext",
    @"C:\Temp\dir_test\file_thats_not_a_dir",
    @"C:\Temp\dir_test\notadir.txt",
    // doesn't exist
    @"C:\Temp\dir_test\dne_folder_is_a_dir",
    @"C:\Temp\dir_test\dne_folder_trailing_slash\",
    @"C:\Temp\dir_test\non_existing_folder_with.ext",
    @"C:\Temp\dir_test\dne_file_thats_not_a_dir",
    @"C:\Temp\dir_test\dne_notadir.txt",        
};

foreach(var path in paths) {
    IsFolder(path/*, false*/).Dump(path);
}

Results

C:\Temp\dir_test\folder_is_a_dir
  True 
C:\Temp\dir_test\is_a_dir_trailing_slash\
  True 
C:\Temp\dir_test\existing_folder_with.ext
  True 
C:\Temp\dir_test\file_thats_not_a_dir
  False 
C:\Temp\dir_test\notadir.txt
  False 
C:\Temp\dir_test\dne_folder_is_a_dir
  True 
C:\Temp\dir_test\dne_folder_trailing_slash\
  True 
C:\Temp\dir_test\non_existing_folder_with.ext
  False (this is the weird one)
C:\Temp\dir_test\dne_file_thats_not_a_dir
  True 
C:\Temp\dir_test\dne_notadir.txt
  False 

Method

/// <summary>
/// Whether the <paramref name="path"/> is a folder (existing or not); 
/// optionally assume that if it doesn't "look like" a file then it's a directory.
/// </summary>
/// <param name="path">Path to check</param>
/// <param name="assumeDneLookAlike">If the <paramref name="path"/> doesn't exist, does it at least look like a directory name?  As in, it doesn't look like a file.</param>
/// <returns><c>True</c> if a folder/directory, <c>false</c> if not.</returns>
public static bool IsFolder(string path, bool assumeDneLookAlike = true)
{
    // https://stackoverflow.com/questions/1395205/better-way-to-check-if-path-is-a-file-or-a-directory
    // turns out to be about the same as https://stackoverflow.com/a/19596821/1037948

    // check in order of verisimilitude

    // exists or ends with a directory separator -- files cannot end with directory separator, right?
    if (Directory.Exists(path)
        // use system values rather than assume slashes
        || path.EndsWith("" + Path.DirectorySeparatorChar)
        || path.EndsWith("" + Path.AltDirectorySeparatorChar))
        return true;

    // if we know for sure that it's an actual file...
    if (File.Exists(path))
        return false;

    // if it has an extension it should be a file, so vice versa
    // although technically directories can have extensions...
    if (!Path.HasExtension(path) && assumeDneLookAlike)
        return true;

    // only works for existing files, kinda redundant with `.Exists` above
    //if( File.GetAttributes(path).HasFlag(FileAttributes.Directory) ) ...; 

    // no idea -- could return an 'indeterminate' value (nullable bool)
    // or assume that if we don't know then it's not a folder
    return false;
}

How to get/generate the create statement for an existing hive table?

Describe Formatted/Extended will show the data definition of the table in hive

hive> describe Formatted dbname.tablename;

Get data from fs.readFile

const fs = require('fs')
function readDemo1(file1) {
    return new Promise(function (resolve, reject) {
        fs.readFile(file1, 'utf8', function (err, dataDemo1) {
            if (err)
                reject(err);
            else
                resolve(dataDemo1);
        });
    });
}
async function copyFile() {

    try {
        let dataDemo1 = await readDemo1('url')
        dataDemo1 += '\n' +  await readDemo1('url')

        await writeDemo2(dataDemo1)
        console.log(dataDemo1)
    } catch (error) {
        console.error(error);
    }
}
copyFile();

function writeDemo2(dataDemo1) {
    return new Promise(function(resolve, reject) {
      fs.writeFile('text.txt', dataDemo1, 'utf8', function(err) {
        if (err)
          reject(err);
        else
          resolve("Promise Success!");
      });
    });
  }

How to restore the menu bar in Visual Studio Code

press Alt to seee the Menubar and then go to view - appearance and remove the check from the fullscreen option

"Server Tomcat v7.0 Server at localhost failed to start" without stack trace while it works in terminal

double click on apache server in eclipse server tab. now change tomacat admin port to 8010, http port change to 8082 and Ajp port change to 8011.

Centering a Twitter Bootstrap button

Question is a bit old, but easy way is to apply .center-block to button.

Amazon Linux: apt-get: command not found

Try to install your application by using yum command yum install application_name

RAW POST using cURL in PHP

I just found the solution, kind of answering to my own question in case anyone else stumbles upon it.

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL,            "http://url/url/url" );
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1 );
curl_setopt($ch, CURLOPT_POST,           1 );
curl_setopt($ch, CURLOPT_POSTFIELDS,     "body goes here" ); 
curl_setopt($ch, CURLOPT_HTTPHEADER,     array('Content-Type: text/plain')); 

$result=curl_exec ($ch);

Renew Provisioning Profile

Update March 2013

The expiry date of the provisioning profile is linked to the expiry date of the developer certificate. And I didn't want to wait for it to expire so here is what I did -

  • Go to the iOS Provisioning portal
  • Revoke the current certificate
  • In Xcode > Organizer go to the Provisioning profiles page (under Library)
  • Press refresh and it will prompt you to create a new developer certificate since the current one has been revoked
  • Follow the steps to create one
  • Go back to the iOS provisioning portal for your distribution profiles and change something about it so it will enable the submit button.
  • Submit it and the date of the new certificate will get applied to it

MySQL Cannot drop index needed in a foreign key constraint

In my case I dropped the foreign key and I still could not drop the index. That was because there was yet another table that had a foreign key to this table on the same fields. After I dropped the foreign key on the other table I could drop the indexes on this table.

How do I concatenate a string with a variable?

Another way to do it simpler using jquery.

sample:

function add(product_id){

    // the code to add the product
    //updating the div, here I just change the text inside the div. 
    //You can do anything with jquery, like change style, border etc.
    $("#added_"+product_id).html('the product was added to list');

}

Where product_id is the javascript var and$("#added_"+product_id) is a div id concatenated with product_id, the var from function add.

Best Regards!