Programs & Examples On #Server migration

How do I wait for an asynchronously dispatched block to finish?

I have to wait until a UIWebView is loaded before running my method, I was able to get this working by performing UIWebView ready checks on main thread using GCD in combination with semaphore methods mentioned in this thread. Final code looks like this:

-(void)myMethod {

    if (![self isWebViewLoaded]) {

            dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);

            __block BOOL isWebViewLoaded = NO;

            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

                while (!isWebViewLoaded) {

                    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)((0.0) * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                        isWebViewLoaded = [self isWebViewLoaded];
                    });

                    [NSThread sleepForTimeInterval:0.1];//check again if it's loaded every 0.1s

                }

                dispatch_sync(dispatch_get_main_queue(), ^{
                    dispatch_semaphore_signal(semaphore);
                });

            });

            while (dispatch_semaphore_wait(semaphore, DISPATCH_TIME_NOW)) {
                [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:0]];
            }

        }

    }

    //Run rest of method here after web view is loaded

}

Understanding REST: Verbs, error codes, and authentication

For the examples you stated I'd use the following:

activate_login

POST /users/1/activation

deactivate_login

DELETE /users/1/activation

change_password

PUT /passwords (this assumes the user is authenticated)

add_credit

POST /credits (this assumes the user is authenticated)

For errors you'd return the error in the body in the format that you got the request in, so if you receive:

DELETE /users/1.xml

You'd send the response back in XML, the same would be true for JSON etc...

For authentication you should use http authentication.

CORS Access-Control-Allow-Headers wildcard being ignored?

here's the incantation for nginx, inside a

location / {
    # Simple requests
    if ($request_method ~* "(GET|POST)") {
      add_header "Access-Control-Allow-Origin"  *;
    }

    # Preflighted requests
    if ($request_method = OPTIONS ) {
      add_header "Access-Control-Allow-Origin"  *;
      add_header "Access-Control-Allow-Methods" "GET, POST, OPTIONS, HEAD";
      add_header "Access-Control-Allow-Headers" "Authorization, Origin, X-Requested-With, Content-Type, Accept";
    }

}

<button> vs. <input type="button" />. Which to use?

<button>
  • by default behaves like if it had a "type="submit" attribute
  • can be used without a form as well as in forms.
  • text or html content allowed
  • css pseudo elements allowed (like :before)
  • tag name is usually unique to a single form

vs.

<input type='button'>
  • type should be set to 'submit' to behave as a submitting element
  • can only be used in forms.
  • only text content allowed
  • no css pseudo elements
  • same tag name as most of the forms elements (inputs)

--
in modern browsers, both elements are easily styleable with css but in most cases, button element is preferred as you can style more with inner html and pseudo elements

CREATE DATABASE permission denied in database 'master' (EF code-first)

Run Visual Studio as Administrator and put your SQL SERVER authentication login (who has the permission to create a DB) and password in the connection string, it worked for me

How to select and change value of table cell with jQuery?

You can do this :

<table id="table_header">
<tr>
   <td contenteditable="true">a</td>
   <td contenteditable="true">b</td>
   <td contenteditable="true">c</td>
</tr>
</table>

Is the Javascript date object always one day off?

You are using the ISO date string format which, according to this page, causes the date to be constructed using the UTC timezone:

Note: parsing of date strings with the Date constructor (and Date.parse, they are equivalent) is strongly discouraged due to browser differences and inconsistencies. Support for RFC 2822 format strings is by convention only. Support for ISO 8601 formats differs in that date-only strings (e.g. "1970-01-01") are treated as UTC, not local.

If you format the text differently, such as "Jan 01 1970", then (at least on my machine) it uses your local timezone.

Mocha / Chai expect.to.throw not catching thrown errors

And if you are already using ES6/ES2015 then you can also use an arrow function. It is basically the same as using a normal anonymous function but shorter.

expect(() => model.get('z')).to.throw('Property does not exist in model schema.');

Python object deleting itself

In this specific context, your example doesn't make a lot of sense.

When a Being picks up an Item, the item retains an individual existence. It doesn't disappear because it's been picked up. It still exists, but it's (a) in the same location as the Being, and (b) no longer eligible to be picked up. While it's had a state change, it still exists.

There is a two-way association between Being and Item. The Being has the Item in a collection. The Item is associated with a Being.

When an Item is picked up by a Being, two things have to happen.

  • The Being how adds the Item in some set of items. Your bag attribute, for example, could be such a set. [A list is a poor choice -- does order matter in the bag?]

  • The Item's location changes from where it used to be to the Being's location. There are probably two classes os Items - those with an independent sense of location (because they move around by themselves) and items that have to delegate location to the Being or Place where they're sitting.

Under no circumstances does any Python object ever need to get deleted. If an item is "destroyed", then it's not in a Being's bag. It's not in a location.

player.bag.remove(cat)

Is all that's required to let the cat out of the bag. Since the cat is not used anywhere else, it will both exist as "used" memory and not exist because nothing in your program can access it. It will quietly vanish from memory when some quantum event occurs and memory references are garbage collected.

On the other hand,

here.add( cat )
player.bag.remove(cat)

Will put the cat in the current location. The cat continues to exist, and will not be put out with the garbage.

Why binary_crossentropy and categorical_crossentropy give different performances for the same problem?

I came across an "inverted" issue — I was getting good results with categorical_crossentropy (with 2 classes) and poor with binary_crossentropy. It seems that problem was with wrong activation function. The correct settings were:

  • for binary_crossentropy: sigmoid activation, scalar target
  • for categorical_crossentropy: softmax activation, one-hot encoded target

How to print object array in JavaScript?

Simple function to alert contents of an object or an array .
Call this function with an array or string or an object it alerts the contents.

Function

function print_r(printthis, returnoutput) {
    var output = '';

    if($.isArray(printthis) || typeof(printthis) == 'object') {
        for(var i in printthis) {
            output += i + ' : ' + print_r(printthis[i], true) + '\n';
        }
    }else {
        output += printthis;
    }
    if(returnoutput && returnoutput == true) {
        return output;
    }else {
        alert(output);
    }
}

Usage

var data = [1, 2, 3, 4];
print_r(data);

Internet Explorer 11- issue with security certificate error prompt

If you updated Internet Explorer and began having technical problems, you can use the Compatibility View feature to emulate a previous version of Internet Explorer.

For instructions, see the section below that corresponds with your version. To find your version number, click Help > About Internet Explorer. Internet Explorer 11

To edit the Compatibility View list:

Open the desktop, and then tap or click the Internet Explorer icon on the taskbar.
Tap or click the Tools button (Image), and then tap or click Compatibility View settings.
To remove a website:
Click the website(s) where you would like to turn off Compatibility View, clicking Remove after each one.
To add a website:
Under Add this website, enter the website(s) where you would like to turn on Compatibility View, clicking Add after each one.

How to horizontally center an element

Give some width to the inner div and add margin:0 auto; in the CSS property.

Get the Query Executed in Laravel 3/4

Using the query log doesnt give you the actual RAW query being executed, especially if there are bound values. This is the best approach to get the raw sql:

DB::table('tablename')->toSql();

or more involved:

$query = Article::whereIn('author_id', [1,2,3])->orderBy('published', 'desc')->toSql();
dd($query);

python pandas convert index to datetime

In my case, my dataframe has the following characteristics

<class 'pandas.core.frame.DataFrame'>
Index: 3040 entries, 15/12/2008 to  
Data columns (total 1 columns):
 #   Column  Non-Null Count  Dtype  
---  ------  --------------  -----  
 0   Close   3038 non-null   float64
dtypes: float64(1)
memory usage: 47.5+ KB

enter image description here

The first option data.index = pd.to_datetime(data.index) returned

ParserError: String does not contain a date: ParserError: String does not contain a date:

The second option: data.index.to_datetime() returned

AttributeError: 'Index' object has no attribute 'to_datetime'

It returned

Another option I have tested is. data.index = pd.to_datetime(data.index)

It returned: ParserError: String does not contain a date:

What could be my problem? Thanks

Drop all duplicate rows across multiple columns in Python Pandas

Try these various things

df = pd.DataFrame({"A":["foo", "foo", "foo", "bar","foo"], "B":[0,1,1,1,1], "C":["A","A","B","A","A"]})

>>>df.drop_duplicates( "A" , keep='first')

or

>>>df.drop_duplicates( keep='first')

or

>>>df.drop_duplicates( keep='last')

How to get number of rows using SqlDataReader in C#

to complete of Pit answer and for better perfromance : get all in one query and use NextResult method.

using (var sqlCon = new SqlConnection("Server=127.0.0.1;Database=MyDb;User Id=Me;Password=glop;"))
{
    sqlCon.Open();
    var com = sqlCon.CreateCommand();
    com.CommandText = "select * from BigTable;select @@ROWCOUNT;";
    using (var reader = com.ExecuteReader())
    {
        while(reader.read()){
            //iterate code
        }
        int totalRow = 0 ;
        reader.NextResult(); // 
        if(reader.read()){
            totalRow = (int)reader[0];
        }
    }
    sqlCon.Close();
}

error: member access into incomplete type : forward declaration of

Move doSomething definition outside of its class declaration and after B and also make add accessible to A by public-ing it or friend-ing it.

class B;

class A
{
    void doSomething(B * b);
};

class B
{
public:
    void add() {}
};

void A::doSomething(B * b)
{
    b->add();
}

Reset all the items in a form

There is a very effective way to use to clear or reset Windows Form C# controls like TextBox, ComboBox, RadioButton, CheckBox, DateTimePicker etc.

private void btnClear_Click(object sender, EventArgs e)
{
    Utilities.ClearAllControls(this);
}

internal class Utilities
{
    internal static void ClearAllControls(Control control)
    {
        foreach (Control c in control.Controls)
        {
            if (c is TextBox)
            {
                ((TextBox)c).Clear();
            }
            else if (c is ComboBox)
            {
                ((ComboBox)c).SelectedIndex = -1;
            }
            else if (c is RadioButton)
            {
                ((RadioButton)c).Checked = false;
            }
            else if (c is CheckBox)
            {
                ((CheckBox)c).Checked = false;
            }
            else if (c is DateTimePicker)
            {
                ((DateTimePicker)c).Value = DateTime.Now; // or null 
            }
        }
    }
}

To accomplish this with overall user experience in c# we can use one statement to clear them. Pretty straight forward so far, above is the code.

Extract source code from .jar file

Your JAR may contain source and javadoc, in which case you can simply use jar xf my.jar to extract them.

Otherwise you can use a decompiler as mentioned in adarshr's answer:

Use JD GUI. Open the application, drag and drop your JAR file into it.

Java heap terminology: young, old and permanent generations?

This seems like a common misunderstanding. In Oracle's JVM, the permanent generation is not part of the heap. It's a separate space for class definitions and related data. In Java 6 and earlier, interned strings were also stored in the permanent generation. In Java 7, interned strings are stored in the main object heap.

Here is a good post on permanent generation.

I like the descriptions given for each space in Oracle's guide on JConsole:

For the HotSpot Java VM, the memory pools for serial garbage collection are the following.

  • Eden Space (heap): The pool from which memory is initially allocated for most objects.
  • Survivor Space (heap): The pool containing objects that have survived the garbage collection of the Eden space.
  • Tenured Generation (heap): The pool containing objects that have existed for some time in the survivor space.
  • Permanent Generation (non-heap): The pool containing all the reflective data of the virtual machine itself, such as class and method objects. With Java VMs that use class data sharing, this generation is divided into read-only and read-write areas.
  • Code Cache (non-heap): The HotSpot Java VM also includes a code cache, containing memory that is used for compilation and storage of native code.

Java uses generational garbage collection. This means that if you have an object foo (which is an instance of some class), the more garbage collection events it survives (if there are still references to it), the further it gets promoted. It starts in the young generation (which itself is divided into multiple spaces - Eden and Survivor) and would eventually end up in the tenured generation if it survived long enough.

IOError: [Errno 22] invalid mode ('r') or filename: 'c:\\Python27\test.txt'

always use 'r' to get a raw string when you want to avoid escape.

test_file=open(r'c:\Python27\test.txt','r')

'python' is not recognized as an internal or external command

Option 1 : Select on add environment var during installation Option 2 : Go to C:\Users-> AppData (hidden file) -> Local\Programs\Python\Python38-32(depends on version installed)\Scripts Copy path and add to env vars path.

For me this path worked : C:\Users\Username\AppData\Local\Programs\Python\Python38-32\Scripts

How to get client's IP address using JavaScript?

Include this code in your page : <script type="text/javascript" src="http://l2.io/ip.js"></script>

more doc here

how to get the attribute value of an xml node using java

I'm happy that this snippet works fine:

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document document = db.parse(new File("config.xml"));
NodeList nodeList = document.getElementsByTagName("source");
for(int x=0,size= nodeList.getLength(); x<size; x++) {
    System.out.println(nodeList.item(x).getAttributes().getNamedItem("type").getNodeValue());
} 

How to run .jar file by double click on Windows 7 64-bit?

If you have previously used the right click and opened with \path\to\your\javaw.exe then you will need to remove the following registry key.

[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.jar]

Then run

C:\>assoc .jar=jarfile
C:\>ftype jarfile="C:\path\to\your\javaw.exe" -jar "%1" %*

How to gzip all files in all sub-directories into one compressed file in bash

@amitchhajer 's post works for GNU tar. If someone finds this post and needs it to work on a NON GNU system, they can do this:

tar cvf - folderToCompress | gzip > compressFileName

To expand the archive:

zcat compressFileName | tar xvf -

How to replace case-insensitive literal substrings in Java

I like smas's answer that uses replaceAll with a regular expression. If you are going to be doing the same replacement many times, it makes sense to pre-compile the regular expression once:

import java.util.regex.Pattern;

public class Test { 

    private static final Pattern fooPattern = Pattern.compile("(?i)foo");

    private static removeFoo(s){
        if (s != null) s = fooPattern.matcher(s).replaceAll("");
        return s;
    }

    public static void main(String[] args) {
        System.out.println(removeFoo("FOOBar"));
    }
}

How do I get the max and min values from a set of numbers entered?

here you need to skip int 0 like following:

val = s.nextInt();
  if ((val < min) && (val!=0)) {
      min = val;
  }

display HTML page after loading complete

you can also go for this.... this will only show the HTML section once javascript has loaded.

<!-- Adds the hidden style and removes it when javascript has loaded -->
<style type="text/css">
    .hideAll  {
        visibility:hidden;
     }
</style>

<script type="text/javascript">
    $(window).load(function () {
        $("#tabs").removeClass("hideAll");
    });
</script>

<div id="tabs" class="hideAll">
   ##Content##
</div>

Can my enums have friendly names?

One problem with this trick is that description attribute cannot be localized. I do like a technique by Sacha Barber where he creates his own version of Description attribute which would pick up values from the corresponding resource manager.

http://www.codeproject.com/KB/WPF/FriendlyEnums.aspx

Although the article is around a problem that's generally faced by WPF developers when binding to enums, you can jump directly to the part where he creates the LocalizableDescriptionAttribute.

MySQL/SQL: Group by date only on a Datetime column

Or:

SELECT SUM(foo), DATE(mydate) mydate FROM a_table GROUP BY mydate;

More efficient (I think.) Because you don't have to cast mydate twice per row.

File input 'accept' attribute - is it useful?

If the browser uses this attribute, it is only as an help for the user, so he won't upload a multi-megabyte file just to see it rejected by the server...
Same for the <input type="hidden" name="MAX_FILE_SIZE" value="100000"> tag: if the browser uses it, it won't send the file but an error resulting in UPLOAD_ERR_FORM_SIZE (2) error in PHP (not sure how it is handled in other languages).
Note these are helps for the user. Of course, the server must always check the type and size of the file on its end: it is easy to tamper with these values on the client side.

How to set Python's default version to 3.x on OS X?

I'm a little late to the game on this one, but I thought I should post an updated answer since I just encountered this issue for myself. Please note that this will only apply to a Mac-based setup (I haven't tried it with Windows or any flavor of Linux).

The simplest way to get this working is to install Python via Brew. If you don't have brew installed, you will need to do that first. Once installed, do the following in at the terminal:

brew install python

This will install Python 3. After it's installed, run this:

ls -l /usr/local/bin/python*

You will see all of the links created by brew to its Python install. It will look something like this:

lrwxr-xr-x  1 username  admin  36 Oct  1 13:35 /usr/local/bin/python3@ -> ../Cellar/python/3.7.4_1/bin/python3
lrwxr-xr-x  1 username  admin  43 Oct  1 13:35 /usr/local/bin/python3-config@ -> ../Cellar/python/3.7.4_1/bin/python3-config
lrwxr-xr-x  1 username  admin  38 Oct  1 13:35 /usr/local/bin/python3.7@ -> ../Cellar/python/3.7.4_1/bin/python3.7
lrwxr-xr-x  1 username  admin  45 Oct  1 13:35 /usr/local/bin/python3.7-config@ -> ../Cellar/python/3.7.4_1/bin/python3.7-config
lrwxr-xr-x  1 username  admin  39 Oct  1 13:35 /usr/local/bin/python3.7m@ -> ../Cellar/python/3.7.4_1/bin/python3.7m
lrwxr-xr-x  1 username  admin  46 Oct  1 13:35 /usr/local/bin/python3.7m-config@ -> ../Cellar/python/3.7.4_1/bin/python3.7m-config

The first row in this example shows the python3 symlink. To set it as the default python symlink run the following:

ln -s -f /usr/local/bin/python3 /usr/local/bin/python

Once set, you can do:

which python

and it should show:

/usr/local/bin/python

You will have to reload your current terminal shell for it to use the new symlink in that shell, however, all newly opened shell sessions will (should) automatically use it. To test this, open a new terminal shell and run the following:

python --version

why windows 7 task scheduler task fails with error 2147942667

I had this same issue.

The solution for me was found in the Microsoft KB Article 2452723:

Windows Vista onwards scheduled tasks fail to run if the path in "Start in (Optional)" field has quotes

Basically, edit your scheduled task and take the Quotes out of the Start In field:

  1. Open your Scheduled Task
  2. Switch to "Actions" tab
  3. Open your Action
  4. Remove Quotes (") from the field "Start in (optional)"
  5. Save and close all open dialogs

Edit Action Dialog Box

To get the relevant error message:

1) Convert 2147942667 to hex: 8007010B
2) Take last 4 digits (010B) and convert to decimal: 267
3) Run: net helpmsg 267
4) Result: "The directory name is invalid."

Command Prompt Window

Hashmap does not work with int, char

Generics only support object types, not primitives. Unlike C++ templates, generics don't involve code generatation and there is only one HashMap code regardless of the number of generic types of it you use.

Trove4J gets around this by pre-generating selected collections to use primitives and supports TCharIntHashMap which to can wrap to support the Map<Character, Integer> if you need to.

TCharIntHashMap: An open addressed Map implementation for char keys and int values.

How to stop a JavaScript for loop?

To stop a for loop early in JavaScript, you use break:

var remSize = [], 
    szString,
    remData,
    remIndex,
    i;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remIndex = -1; // Set a default if we don't find it
for (i = 0; i < remSize.length; i++) {      
     // I'm looking for the index i, when the condition is true
     if (remSize[i].size === remData.size) {
          remIndex = i;
          break;       // <=== breaks out of the loop early
     }
}

If you're in an ES2015 (aka ES6) environment, for this specific use case, you can use Array#findIndex (to find the entry's index) or Array#find (to find the entry itself), both of which can be shimmed/polyfilled:

var remSize = [], 
    szString,
    remData,
    remIndex;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remIndex = remSize.findIndex(function(entry) {
     return entry.size === remData.size;
});

Array#find:

var remSize = [], 
    szString,
    remData,
    remEntry;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remEntry = remSize.find(function(entry) {
     return entry.size === remData.size;
});

Array#findIndex stops the first time the callback returns a truthy value, returning the index for that call to the callback; it returns -1 if the callback never returns a truthy value. Array#find also stops when it finds what you're looking for, but it returns the entry, not its index (or undefined if the callback never returns a truthy value).

If you're using an ES5-compatible environment (or an ES5 shim), you can use the new some function on arrays, which calls a callback until the callback returns a truthy value:

var remSize = [], 
    szString,
    remData,
    remIndex;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remIndex = -1; // <== Set a default if we don't find it
remSize.some(function(entry, index) {
    if (entry.size === remData.size) {
        remIndex = index;
        return true; // <== Equivalent of break for `Array#some`
    }
});

If you're using jQuery, you can use jQuery.each to loop through an array; that would look like this:

var remSize = [], 
    szString,
    remData,
    remIndex;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remIndex = -1; // <== Set a default if we don't find it
jQuery.each(remSize, function(index, entry) {
    if (entry.size === remData.size) {
        remIndex = index;
        return false; // <== Equivalent of break for jQuery.each
    }
});

startForeground fail after upgrade to Android 8.1

In my case, it's because we tried to post a notification without specifying the NotificationChannel:

public static final String NOTIFICATION_CHANNEL_ID_SERVICE = "com.mypackage.service";
public static final String NOTIFICATION_CHANNEL_ID_TASK = "com.mypackage.download_info";

public void initChannel(){
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        NotificationManager nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        nm.createNotificationChannel(new NotificationChannel(NOTIFICATION_CHANNEL_ID_SERVICE, "App Service", NotificationManager.IMPORTANCE_DEFAULT));
        nm.createNotificationChannel(new NotificationChannel(NOTIFICATION_CHANNEL_ID_INFO, "Download Info", NotificationManager.IMPORTANCE_DEFAULT));
    }
}

The best place to put above code is in onCreate() method in the Application class, so that we just need to declare it once for all:

public class App extends Application {

    @Override
    public void onCreate() {
        super.onCreate();
        initChannel();
    }
}

After we set this up, we can use notification with the channelId we just specified:

Intent i = new Intent(this, MainActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent pi = PendingIntent.getActivity(this, 0, i, PendingIntent.FLAG_UPDATE_CURRENT);
NotificationCompat.Builder builder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID_INFO);
            .setContentIntent(pi)
            .setWhen(System.currentTimeMillis())
            .setContentTitle("VirtualBox.exe")
            .setContentText("Download completed")
            .setSmallIcon(R.mipmap.ic_launcher);

Then, we can use it to post a notification:

int notifId = 45;
NotificationManager nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
nm.notify(notifId, builder.build());

If you want to use it as foreground service's notification:

startForeground(notifId, builder.build());

How do I put a variable inside a string?

Oh, the many, many ways...

String concatenation:

plot.savefig('hanning' + str(num) + '.pdf')

Conversion Specifier:

plot.savefig('hanning%s.pdf' % num)

Using local variable names:

plot.savefig('hanning%(num)s.pdf' % locals()) # Neat trick

Using str.format():

plot.savefig('hanning{0}.pdf'.format(num)) # Note: This is the new preferred way

Using f-strings:

plot.savefig(f'hanning{num}.pdf') # added in Python 3.6

Using string.Template:

plot.savefig(string.Template('hanning${num}.pdf').substitute(locals()))

How to draw a filled circle in Java?

public void paintComponent(Graphics g) {
   super.paintComponent(g);
   Graphics2D g2d = (Graphics2D)g;
   // Assume x, y, and diameter are instance variables.
   Ellipse2D.Double circle = new Ellipse2D.Double(x, y, diameter, diameter);
   g2d.fill(circle);
   ...
}

Here are some docs about paintComponent (link).

You should override that method in your JPanel and do something similar to the code snippet above.

In your ActionListener you should specify x, y, diameter and call repaint().

Remove Elements from a HashSet while Iterating

Java 8 Collection has a nice method called removeIf that makes things easier and safer. From the API docs:

default boolean removeIf(Predicate<? super E> filter)
Removes all of the elements of this collection that satisfy the given predicate. 
Errors or runtime exceptions thrown during iteration or by the predicate 
are relayed to the caller.

Interesting note:

The default implementation traverses all elements of the collection using its iterator(). 
Each matching element is removed using Iterator.remove().

From: https://docs.oracle.com/javase/8/docs/api/java/util/Collection.html#removeIf-java.util.function.Predicate-

How to convert string to double with proper cultureinfo

I took some help from MSDN, but this is my answer:

double number;
string localStringNumber;
string doubleNumericValueasString = "65.89875";
System.Globalization.NumberStyles style = System.Globalization.NumberStyles.AllowDecimalPoint;

if (double.TryParse(doubleNumericValueasString, style, System.Globalization.CultureInfo.InvariantCulture, out number))
    Console.WriteLine("Converted '{0}' to {1}.", doubleNumericValueasString, number);
else
    Console.WriteLine("Unable to convert '{0}'.", doubleNumericValueasString);
localStringNumber =number.ToString(System.Globalization.CultureInfo.CreateSpecificCulture("de-DE"));

Can I set an opacity only to the background image of a div?

So here is an other way:

background-image: linear-gradient(rgba(255,255,255,0.5), rgba(255,255,255,0.5)), url("your_image.png");

How to echo out the values of this array?

The problem here is in your explode statement

//$item['date'] presumably = 20120514.  Do a print of this
$eventDate = trim($item['date']);

//This explodes on , but there is no , in $eventDate
//You also have a limit of 2 set in the below explode statement
$myarray = (explode(',', $eventDate, 2));

 //$myarray is currently = to '20'

 foreach ($myarray as $value) {
    //Now you are iterating through a string
    echo $value;
 }

Try changing your initial $item['date'] to be 2012,04,30 if that's what you're trying to do. Otherwise I'm not entirely sure what you're trying to print.

Scrolling a flexbox with overflowing content

One issue that I've come across is that to have a scrollbar a n element needs a height to be specified (and not as a %).

The trick is to nest another set of divs within each column, and set the column parent's display to flex with flex-direction: column.

<style>
    html, body {
        height: 100%;
        margin: 0;
        padding: 0;
    }

    body {
        overflow-y: hidden;
        overflow-x: hidden;
        color: white;
    }

    .base-container {
        display: flex;
        flex: 1;
        flex-direction: column;
        width: 100%;
        height: 100%;
        overflow-y: hidden;
        align-items: stretch;
    }

    .title {
        flex: 0 0 50px;
        color: black;
    }

    .container {
        flex: 1 1 auto;
        display: flex;
        flex-direction: column;
    }

        .container .header {
            flex: 0 0 50px;
            background-color: red;
        }

        .container .body {
            flex: 1 1 auto;
            display: flex;
            flex-direction: row;
        }

            .container .body .left {
                display: flex;
                flex-direction: column;
                flex: 0 0 80px;
                background-color: blue;
            }
                .container .body .left .content,
                .container .body .main .content,
                .container .body .right .content {
                    flex: 1 1 auto;
                    overflow-y: auto;
                    height: 100px;
                }
                .container .body .main .content.noscrollbar {
                    overflow-y: hidden;
                }

            .container .body .main {
                display: flex;
                flex-direction: column;
                flex: 1 1 auto;
                background-color: green;
            }

            .container .body .right {
                display: flex;
                flex-direction: column;
                flex: 0 0 300px;
                background-color: yellow;
                color: black;
            }

    .test {
        margin: 5px 5px;
        border: 1px solid white;
        height: calc(100% - 10px);
    }
</style>

And here's the html:

<div class="base-container">
    <div class="title">
        Title
    </div>
    <div class="container">
        <div class="header">
            Header
        </div>
        <div class="body">
            <div class="left">
                <div class="content">
                    <ul>
                        <li>1</li>
                        <li>2</li>
                        <li>3</li>
                        <li>4</li>
                        <li>5</li>
                        <li>6</li>
                        <li>7</li>
                        <li>8</li>
                        <li>9</li>
                        <li>10</li>
                        <li>12</li>
                        <li>13</li>
                        <li>14</li>
                        <li>15</li>
                        <li>16</li>
                        <li>17</li>
                        <li>18</li>
                        <li>19</li>
                        <li>20</li>
                        <li>21</li>
                        <li>22</li>
                        <li>23</li>
                        <li>24</li>
                    </ul>
                </div>
            </div>
            <div class="main">
                <div class="content noscrollbar">
                    <div class="test">Test</div>
                </div>
            </div>
            <div class="right">
                <div class="content">
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>Right</div>
                    <div>End</div>
                </div>
            </div>
        </div>
    </div>
</div>

https://jsfiddle.net/LiamFlavelle/czpjdfr4/

how to show progress bar(circle) in an activity having a listview before loading the listview with data

You can do this easier.
Source: http://www.tutorialspoint.com/android/android_loading_spinner.htm
It helped me.

Layout:

<ProgressBar
   android:id="@+id/progressBar1"
   style="?android:attr/progressBarStyleLarge"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_centerHorizontal="true" />

After defining it in xml, you have to get its reference in java file through ProgressBar class. Its syntax is given below:

private ProgressBar spinner;
spinner = (ProgressBar)findViewById(R.id.progressBar1);

After that you can make its disappear , and bring it back when needed through setVisibility Method. Its syntax is given below:

spinner.setVisibility(View.GONE);
spinner.setVisibility(View.VISIBLE);

Convert date to another timezone in JavaScript

Got it !

Wanted to force the date shown = server date, no mattter the local settings (UTC).

My server is GMT-6 --> new Date().getTimezoneOffset() = 360.

myTZO = 360;
myNewDate=new Date(myOldDateObj.getTime() + (60000*(myOldDateObj.getTimezoneOffset()-myTZO)));
alert(myNewDate);

Laravel - Session store not set on request

in my case it was just to put return ; at the end of function where i have set session

GIT_DISCOVERY_ACROSS_FILESYSTEM not set

Check whether you are actually under a github repo.

So, listing of .git/ should give you results..otherwise you may be some level outside your repo.

Now, cd to your repo and you are good to go.

Convert HTML string to image

       <!--ForExport data in iamge -->
        <script type="text/javascript">
            function ConvertToImage(btnExport) {
                html2canvas($("#dvTable")[0]).then(function (canvas) {
                    var base64 = canvas.toDataURL();
                    $("[id*=hfImageData]").val(base64);
                    __doPostBack(btnExport.name, "");
                });
                return false;
            }
        </script>

        <!--ForExport data in iamge -->

        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
        <script src="../js/html2canvas.min.js"></script> 





<table>
                <tr>
                    <td valign="top">
                        <asp:Button ID="btnExport" Text="Download Back" runat="server" UseSubmitBehavior="false"
                            OnClick="ExportToImage" OnClientClick="return ConvertToImage(this)" />
                        <div id="dvTable" class="divsection2" style="width: 350px">
                            <asp:HiddenField ID="hfImageData" runat="server" />
                            <table width="100%">
                                <tr>
                                    <td>
                                        <br />

                                    </td>
                                </tr>
                                <tr>
                                    <td>
                                        <asp:Label ID="Labelgg" runat="server" CssClass="labans4" Text=""></asp:Label>
                                    </td>
                                </tr>

                            </table>
                        </div>
                    </td>
                </tr>
            </table>


         protected void ExportToImage(object sender, EventArgs e)
                {
                    string base64 = Request.Form[hfImageData.UniqueID].Split(',')[1];
                    byte[] bytes = Convert.FromBase64String(base64);
                    Response.Clear();
                    Response.ContentType = "image/png";
                    Response.AddHeader("Content-Disposition", "attachment; filename=name.png");
                    Response.Buffer = true;
                    Response.Cache.SetCacheability(HttpCacheability.NoCache);
                    Response.BinaryWrite(bytes);
                    Response.End();

                }

"SMTP Error: Could not authenticate" in PHPMailer

I had the same problem with authentication. The fix was to set up 2-step verification and create an application specific password for the device ( error messages for blocking the device will appear in your account settings->"Notifications and alerts" if you problem is the same with mine)

SOAP-ERROR: Parsing WSDL: Couldn't load from <URL>

add the dns entry to your system hosts file
for example:http://aaa.com/service.asmx?WSDL
you can get the aaa.com's ip address with ping
and then add to the hosts file

How to remove border of drop down list : CSS

You could simply use:

select {
    border: none;
    outline: none;
    scroll-behavior: smooth;
}

As the drop down list border is non editable you can not do anything with that but surely this will fix your initial outlook.

Angular 2: How to style host element of the component?

Try the :host > /deep/ :

Add the following to the parent.component.less file

:host {
    /deep/ app-child-component {
       //your child style
    }
}

Replace the app-child-component by your child selector

Get current value selected in dropdown using jQuery

Check it Out-->

For getting text

$("#selme").change(function(){
 $(this[this.selectedIndex]).text();
});

For getting value

$("#selme").change(function(){
 $(this[this.selectedIndex]).val();
});

Hiding a sheet in Excel 2007 (with a password) OR hide VBA code in Excel

Here is what you do in Excel 2003:

  1. In your sheet of interest, go to Format -> Sheet -> Hide and hide your sheet.
  2. Go to Tools -> Protection -> Protect Workbook, make sure Structure is selected, and enter your password of choice.

Here is what you do in Excel 2007:

  1. In your sheet of interest, go to Home ribbon -> Format -> Hide & Unhide -> Hide Sheet and hide your sheet.
  2. Go to Review ribbon -> Protect Workbook, make sure Structure is selected, and enter your password of choice.

Once this is done, the sheet is hidden and cannot be unhidden without the password. Make sense?


If you really need to keep some calculations secret, try this: use Access (or another Excel workbook or some other DB of your choice) to calculate what you need calculated, and export only the "unclassified" results to your Excel workbook.

Delete a row from a table by id

How about:

function deleteRow(rowid)  
{   
    var row = document.getElementById(rowid);
    row.parentNode.removeChild(row);
}

And, if that fails, this should really work:

function deleteRow(rowid)  
{   
    var row = document.getElementById(rowid);
    var table = row.parentNode;
    while ( table && table.tagName != 'TABLE' )
        table = table.parentNode;
    if ( !table )
        return;
    table.deleteRow(row.rowIndex);
}

PHP GuzzleHttp. How to make a post request with params?

Try this

$client = new \GuzzleHttp\Client();
$client->post(
    'http://www.example.com/user/create',
    array(
        'form_params' => array(
            'email' => '[email protected]',
            'name' => 'Test user',
            'password' => 'testpassword'
        )
    )
);

Checking if any elements in one list are in another

I wrote the following code in one of my projects. It basically compares each individual element of the list. Feel free to use it, if it works for your requirement.

def reachedGoal(a,b):
    if(len(a)!=len(b)):
        raise ValueError("Wrong lists provided")

    for val1 in range(0,len(a)):
        temp1=a[val1]
        temp2=b[val1]
        for val2 in range(0,len(b)):
            if(temp1[val2]!=temp2[val2]):
                return False
    return True

Selenium Web Driver & Java. Element is not clickable at point (x, y). Other element would receive the click

In case you need to use it with Javascript

We can use arguments[0].click() to simulate click operation.

var element = element(by.linkText('webdriverjs'));
browser.executeScript("arguments[0].click()",element);

JavaScript code to stop form submission

Base on @Vikram Pudi answer, we can also do like this with pure Javascript

<form onsubmit="submitForm(event)">
    <input type="text">
    <input type="submit">
</form>

<script type="text/javascript">

    function submitForm(event){
        event.preventDefault();


    }
</script>

Gradients on UIView and UILabels On iPhone

You can use Core Graphics to draw the gradient, as pointed to in Mike's response. As a more detailed example, you could create a UIView subclass to use as a background for your UILabel. In that UIView subclass, override the drawRect: method and insert code similar to the following:

- (void)drawRect:(CGRect)rect 
{
    CGContextRef currentContext = UIGraphicsGetCurrentContext();

    CGGradientRef glossGradient;
    CGColorSpaceRef rgbColorspace;
    size_t num_locations = 2;
    CGFloat locations[2] = { 0.0, 1.0 };
    CGFloat components[8] = { 1.0, 1.0, 1.0, 0.35,  // Start color
         1.0, 1.0, 1.0, 0.06 }; // End color

    rgbColorspace = CGColorSpaceCreateDeviceRGB();
    glossGradient = CGGradientCreateWithColorComponents(rgbColorspace, components, locations, num_locations);

    CGRect currentBounds = self.bounds;
    CGPoint topCenter = CGPointMake(CGRectGetMidX(currentBounds), 0.0f);
    CGPoint midCenter = CGPointMake(CGRectGetMidX(currentBounds), CGRectGetMidY(currentBounds));
    CGContextDrawLinearGradient(currentContext, glossGradient, topCenter, midCenter, 0);

    CGGradientRelease(glossGradient);
    CGColorSpaceRelease(rgbColorspace); 
}

This particular example creates a white, glossy-style gradient that is drawn from the top of the UIView to its vertical center. You can set the UIView's backgroundColor to whatever you like and this gloss will be drawn on top of that color. You can also draw a radial gradient using the CGContextDrawRadialGradient function.

You just need to size this UIView appropriately and add your UILabel as a subview of it to get the effect you desire.

EDIT (4/23/2009): Per St3fan's suggestion, I have replaced the view's frame with its bounds in the code. This corrects for the case when the view's origin is not (0,0).

Build fat static library (device + simulator) using Xcode and SDK 4+

I actually just wrote my own script for this purpose. It doesn't use Xcode. (It's based off a similar script in the Gambit Scheme project.)

Basically, it runs ./configure and make three times (for i386, armv7, and armv7s), and combines each of the resulting libraries into a fat lib.

An efficient way to transpose a file in Bash

A oneliner using R...

  cat file | Rscript -e "d <- read.table(file('stdin'), sep=' ', row.names=1, header=T); write.table(t(d), file=stdout(), quote=F, col.names=NA) "

Creating an instance of class

  1. Allocates some dynamic memory from the free store, and creates an object in that memory using its default constructor. You never delete it, so the memory is leaked.
  2. Does exactly the same as 1; in the case of user-defined types, the parentheses are optional.
  3. Allocates some automatic memory, and creates an object in that memory using its default constructor. The memory is released automatically when the object goes out of scope.
  4. Similar to 3. Notionally, the named object foo4 is initialised by default-constructing, copying and destroying a temporary object; usually, this is elided giving the same result as 3.
  5. Allocates a dynamic object, then initialises a second by copying the first. Both objects are leaked; and there's no way to delete the first since you don't keep a pointer to it.
  6. Does exactly the same as 5.
  7. Does not compile. Foo foo5 is a declaration, not an expression; function (and constructor) arguments must be expressions.
  8. Creates a temporary object, and initialises a dynamic object by copying it. Only the dynamic object is leaked; the temporary is destroyed automatically at the end of the full expression. Note that you can create the temporary with just Foo() rather than the equivalent Foo::Foo() (or indeed Foo::Foo::Foo::Foo::Foo())

When do I use each?

  1. Don't, unless you like unnecessary decorations on your code.
  2. When you want to create an object that outlives the current scope. Remember to delete it when you've finished with it, and learn how to use smart pointers to control the lifetime more conveniently.
  3. When you want an object that only exists in the current scope.
  4. Don't, unless you think 3 looks boring and what to add some unnecessary decoration.
  5. Don't, because it leaks memory with no chance of recovery.
  6. Don't, because it leaks memory with no chance of recovery.
  7. Don't, because it won't compile
  8. When you want to create a dynamic Bar from a temporary Foo.

How can I make XSLT work in chrome?

Check http://www.aranedabienesraices.com.ar

This site is built with XML/XSLT client-side. It works on IE6-7-8, FF, O, Safari and Chrome. Are you sending HTTP headers correctly? Are you respecting the same-origin policy?

SQL Server IIF vs CASE

IIF is the same as CASE WHEN <Condition> THEN <true part> ELSE <false part> END. The query plan will be the same. It is, perhaps, "syntactical sugar" as initially implemented.

CASE is portable across all SQL platforms whereas IIF is SQL SERVER 2012+ specific.

What is the difference between Forking and Cloning on GitHub?

When you say you are Forking a repository you are basically creating a copy of the repository under your GitHub ID. The main point to note here is that any changes made to the original repository will be reflected back to your forked repositories(you need to fetch and rebase). However, if you make any changes to your forked repository you will have to explicitly create a pull request to the original repository. If your pull request is approved by the administrator of the original repository, then your changes will be committed/merged with the existing original code-base. Until then, your changes will be reflected only in the copy you forked.

In short:

The Fork & Pull Model lets anyone fork an existing repository and push changes to their personal fork without requiring access be granted to the source repository. The changes must then be pulled into the source repository by the project maintainer.

Note that after forking you can clone your repository (the one under your name) locally on your machine. Make changes in it and push it to your forked repository. However, to reflect your changes in the original repository your pull request must be approved.

Couple of other interesting dicussions -

Are git forks actually git clones?

How do I update a GitHub forked repository?

Performance differences between ArrayList and LinkedList

In a LinkedList the elements have a reference to the element before and after it. In an ArrayList the data structure is just an array.

  1. A LinkedList needs to iterate over N elements to get the Nth element. An ArrayList only needs to return element N of the backing array.

  2. The backing array needs to either be reallocated for the new size and the array copied over or every element after the deleted element needs to be moved up to fill the empty space. A LinkedList just needs to set the previous reference on the element after the removed to the one before the removed and the next reference on the element before the removed element to the element after the removed element. Longer to explain, but faster to do.

  3. Same reason as deletion here.

Get value of a specific object property in C# without knowing the class behind

Reflection and dynamic value access are correct solutions to this question but are quite slow. If your want something faster then you can create dynamic method using expressions:

  object value = GetValue();
  string propertyName = "MyProperty";

  var parameter = Expression.Parameter(typeof(object));
  var cast = Expression.Convert(parameter, value.GetType());
  var propertyGetter = Expression.Property(cast, propertyName);
  var castResult = Expression.Convert(propertyGetter, typeof(object));//for boxing

  var propertyRetriver = Expression.Lambda<Func<object, object>>(castResult, parameter).Compile();

 var retrivedPropertyValue = propertyRetriver(value);

This way is faster if you cache created functions. For instance in dictionary where key would be the actual type of object assuming that property name is not changing or some combination of type and property name.

Return sql rows where field contains ONLY non-alphanumeric characters

SQL Server doesn't have regular expressions. It uses the LIKE pattern matching syntax which isn't the same.

As it happens, you are close. Just need leading+trailing wildcards and move the NOT

 WHERE whatever NOT LIKE '%[a-z0-9]%'

Changing column names of a data frame

If you need to rename not all but multiple column at once when you only know the old column names you can use colnames function and %in% operator. Example:

df = data.frame(bad=1:3, worse=rnorm(3), worst=LETTERS[1:3])

   bad      worse    worst
1   1 -0.77915455       A
2   2  0.06717385       B
3   3 -0.02827242       C

Now you want to change "bad" and "worst" to "good" and "best". You can use

colnames(df)[which(colnames(df) %in% c("bad","worst") )] <- c("good","best")

This results in

  good      worse  best
1    1 -0.6010363    A
2    2  0.7336155    B
3    3  0.9435469    C

Is it possible to install another version of Python to Virtualenv?

You may use pyenv.

There are a lot of different versions anaconda, jython, pypy and so on...

https://github.com/yyuu/pyenv

Installation as simple as pyenv install 3.2.6

pyenv install --list
Available versions:
  2.1.3
  2.2.3
  2.3.7
  2.4
  2.4.1
  2.4.2
  2.4.3
  2.4.4
  2.4.5
  2.4.6
  2.5
  2.5.1
  2.5.2
  2.5.3
  2.5.4
  2.5.5
  2.5.6
  2.6.6

...

Unable to open debugger port in IntelliJ IDEA

I have encountered the same error while using IntelliJ. Since I have started multiple instances of IntelliJ. While starting two instance it started properly. However, when starting another one, it was giving below error.

unable to open debugger port (127.0.0.1:debug-port-number) java.net.socketexception interrupted function call accept failed

There are basically two places you can check your ports related to debugging in IntelliJ

  1. JMX port - you can find this is enter image description here
  2. In Startup/Configuration, there is debug option just click this. enter image description here

What to Check: If IntelliJ is throwing above error, means issue is any of the above listed ports. To verify this open event log (its available in right corner down) and check the exact message. Event log will have message like below

11:19 PM    Error running 'Tomcat-tp': Address localhost:1098 is already in use

11:19 PM    Error running 'Tomcat-tp': Unable to open debugger port (127.0.0.1:51787): java.net.SocketException "Interrupted function call: accept failed"

Solution-1 Check the JMX port of current intelliJ which is not starting with the working one and verify if JMX ports are not duplicated within IntelliJ instance or any of the software which is running in your machine is not using this port.

Solution-2 If JMX is not duplicated then verify your debug port, check in all IntelliJ instance and do the changes.

Surely either JMX or Debug port is having issue just use unique JMX and Debug port and it will work.

Hope this will help someone.

C++ Array of pointers: delete or delete []?

delete[] monsters is definitely wrong. My heap debugger shows the following output:

allocated non-array memory at 0x3e38f0 (20 bytes)
allocated non-array memory at 0x3e3920 (20 bytes)
allocated non-array memory at 0x3e3950 (20 bytes)
allocated non-array memory at 0x3e3980 (20 bytes)
allocated non-array memory at 0x3e39b0 (20 bytes)
allocated non-array memory at 0x3e39e0 (20 bytes)
releasing     array memory at 0x22ff38

As you can see, you are trying to release with the wrong form of delete (non-array vs. array), and the pointer 0x22ff38 has never been returned by a call to new. The second version shows the correct output:

[allocations omitted for brevity]
releasing non-array memory at 0x3e38f0
releasing non-array memory at 0x3e3920
releasing non-array memory at 0x3e3950
releasing non-array memory at 0x3e3980
releasing non-array memory at 0x3e39b0
releasing non-array memory at 0x3e39e0

Anyway, I prefer a design where manually implementing the destructor is not necessary to begin with.

#include <array>
#include <memory>

class Foo
{
    std::array<std::shared_ptr<Monster>, 6> monsters;

    Foo()
    {
        for (int i = 0; i < 6; ++i)
        {
            monsters[i].reset(new Monster());
        }
    }

    virtual ~Foo()
    {
        // nothing to do manually
    }
};

Detecting value change of input[type=text] in jQuery

This combination of events worked for me:

$("#myTextBox").on("input paste", function() {
   alert($(this).val()); 
});

How do I select last 5 rows in a table without sorting?

Suppose you have an index on id, this will be lightning fast:

SELECT * FROM [MyTable] WHERE [id] > (SELECT MAX([id]) - 5 FROM [MyTable])

Can not find the tag library descriptor for "http://java.sun.com/jsp/jstl/core"

Make sure that both the below jars are present in the build path:

  1. standard-1.1.2.jar
  2. jstl-api-1.2.jar

Maven Dependencies are:

<dependency>
    <groupId>javax.servlet.jsp.jstl</groupId>
    <artifactId>jstl-api</artifactId>
    <version>$1.2</version>
</dependency>

<dependency>
   <groupId>taglibs</groupId>
   <artifactId>standard</artifactId>
   <version>1.1.2</version>
</dependency

How to import CSV file data into a PostgreSQL table?

If you need simple mechanism to import from text/parse multiline CSV you could use:

CREATE TABLE t   -- OR INSERT INTO tab(col_names)
AS
SELECT
   t.f[1] AS col1
  ,t.f[2]::int AS col2
  ,t.f[3]::date AS col3
  ,t.f[4] AS col4
FROM (
  SELECT regexp_split_to_array(l, ',') AS f
  FROM regexp_split_to_table(
$$a,1,2016-01-01,bbb
c,2,2018-01-01,ddd
e,3,2019-01-01,eee$$, '\n') AS l) t;

DBFiddle Demo

require is not defined? Node.js

Node.JS is a server-side technology, not a browser technology. Thus, Node-specific calls, like require(), do not work in the browser.

See browserify or webpack if you wish to serve browser-specific modules from Node.

How to get time difference in minutes in PHP

The answers above are for older versions of PHP. Use the DateTime class to do any date calculations now that PHP 5.3 is the norm. Eg.

$start_date = new DateTime('2007-09-01 04:10:58');
$since_start = $start_date->diff(new DateTime('2012-09-11 10:25:00'));
echo $since_start->days.' days total<br>';
echo $since_start->y.' years<br>';
echo $since_start->m.' months<br>';
echo $since_start->d.' days<br>';
echo $since_start->h.' hours<br>';
echo $since_start->i.' minutes<br>';
echo $since_start->s.' seconds<br>';

$since_start is a DateInterval object. Note that the days property is available (because we used the diff method of the DateTime class to generate the DateInterval object).

The above code will output:

1837 days total
5 years
0 months
10 days
6 hours
14 minutes
2 seconds

To get the total number of minutes:

$minutes = $since_start->days * 24 * 60;
$minutes += $since_start->h * 60;
$minutes += $since_start->i;
echo $minutes.' minutes';

This will output:

2645654 minutes

Which is the actual number of minutes that has passed between the two dates. The DateTime class will take daylight saving (depending on timezone) into account where the "old way" won't. Read the manual about Date and Time http://www.php.net/manual/en/book.datetime.php

Changing the default icon in a Windows Forms application

Add your icon as a Resource (Project > yourprojectname Properties > Resources > Pick "Icons from dropdown > Add Resource (or choose Add Existing File from dropdown if you already have the .ico)

Then:

this.Icon = Properties.Resources.youriconname;

cvc-elt.1: Cannot find the declaration of element 'MyElement'

I had this error for my XXX element and it was because my XSD was wrongly formatted according to javax.xml.bind v2.2.11 . I think it's using an older XSD format but I didn't bother to confirm.

My initial wrong XSD was alike the following:

<xs:element name="Document" type="Document"/>
...
<xs:complexType name="Document">
    <xs:sequence>
        <xs:element name="XXX" type="XXX_TYPE"/>
    </xs:sequence>
</xs:complexType>

The good XSD format for my migration to succeed was the following:

<xs:element name="Document">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref="XXX"/>
        </xs:sequence>
    </xs:complexType>        
</xs:element>
...
<xs:element name="XXX" type="XXX_TYPE"/>

And so on for every similar XSD nodes.

Export database schema into SQL file

Have you tried the Generate Scripts (Right click, tasks, generate scripts) option in SQL Management Studio? Does that produce what you mean by a "SQL File"?

float:left; vs display:inline; vs display:inline-block; vs display:table-cell;

I prefer inline-block, although float is also useful. Table-cell isn't rendered correctly by old IEs (neither does inline-block, but there's the zoom: 1; *display: inline hack that I use frequently). If you have children that have a smaller height than their parent, floats will bring them to the top, whereas inline-block will screw up sometimes.

Most of the time, the browser will interpret everything correctly, unless, of course, it's IE. You always have to check to make sure that IE doesn't suck-- for example, the table-cell concept.

In all reality, yes, it boils down to personal preference.

One technique you could use to get rid of white space would be to set a font-size of 0 to the parent, then give the font-size back to the children, although that's a hassle, and gross.

CSS word-wrapping in div

I'm a little surprised it doesn't just do that. Could there another element inside the div that has a width set to something greater than 250?

Validate SSL certificates with Python

M2Crypto can do the validation. You can also use M2Crypto with Twisted if you like. The Chandler desktop client uses Twisted for networking and M2Crypto for SSL, including certificate validation.

Based on Glyphs comment it seems like M2Crypto does better certificate verification by default than what you can do with pyOpenSSL currently, because M2Crypto checks subjectAltName field too.

I've also blogged on how to get the certificates Mozilla Firefox ships with in Python and usable with Python SSL solutions.

How to use Bootstrap 4 in ASP.NET Core

Try Libman, it's as simple as Bower and you can specify wwwroot/lib/ as the download folder.

Time complexity of nested for-loop

A quick way to explain this is to visualize it.

if both i and j are from 0 to N, it's easy to see O(N^2)

O O O O O O O O
O O O O O O O O
O O O O O O O O
O O O O O O O O
O O O O O O O O
O O O O O O O O
O O O O O O O O
O O O O O O O O

in this case, it's:

O
O O
O O O
O O O O
O O O O O
O O O O O O
O O O O O O O
O O O O O O O O

This comes out to be 1/2 of N^2, which is still O(N^2)

Cannot find mysql.sock

This found it for me:

netstat -ln | grep mysql

Mac OSX

How to use workbook.saveas with automatic Overwrite

To hide the prompt set xls.DisplayAlerts = False

ConflictResolution is not a true or false property, it should be xlLocalSessionChanges

Note that this has nothing to do with displaying the Overwrite prompt though!

Set xls = CreateObject("Excel.Application")    
xls.DisplayAlerts = False
Set wb = xls.Workbooks.Add
fullFilePath = importFolderPath & "\" & "A.xlsx"

wb.SaveAs fullFilePath, AccessMode:=xlExclusive,ConflictResolution:=Excel.XlSaveConflictResolution.xlLocalSessionChanges    
wb.Close (True)

How do you set the startup page for debugging in an ASP.NET MVC application?

Go to your project's properties and set the start page property.

  1. Go to the project's Properties
  2. Go to the Web tab
  3. Select the Specific Page radio button
  4. Type in the desired url in the Specific Page text box

Do you use source control for your database items?

The new Database projects in Visual Studio provide source control and change scripts.

They have a nice tool that compares databases and can generate a script that converts the schema of one into the other, or updates the data in one to match the other.

The db schema is "shredded" to create many, many small .sql files, one per DDL command that describes the DB.

+tom


Additional info 2008-11-30

I have been using it as a developer for the past year and really like it. It makes it easy to compare my dev work to production and generate a script to use for the release. I don't know if it is missing features that DBAs need for "enterprise-type" projects.

Because the schema is "shredded" into sql files the source control works fine.

One gotcha is that you need to have a different mindset when you use a db project. The tool has a "db project" in VS, which is just the sql, plus an automatically generated local database which has the schema and some other admin data -- but none of your application data, plus your local dev db that you use for app data dev work. You rarely are aware of the automatically generated db, but you have to know its there so you can leave it alone :). This special db is clearly recognizable because it has a Guid in its name,

The VS DB Project does a nice job of integrating db changes that other team members have made into your local project/associated db. but you need to take the extra step to compare the project schema with your local dev db schema and apply the mods. It makes sense, but it seems awkward at first.

DB Projects are a very powerful tool. They not only generate scripts but can apply them immediately. Be sure not to destroy your production db with it. ;)

I really like the VS DB projects and I expect to use this tool for all my db projects going forward.

+tom

How do I make a Mac Terminal pop-up/alert? Applescript?

Adding subtitle, title and a sound to the notification:

With AppleScript:

display notification "Notification text" with title "Notification Title" subtitle "Notification sub-title" sound name "Submarine"

With terminal/bash and osascript:

osascript -e 'display notification "Notification text" with title "Notification Title" subtitle "Notification sub-title" sound name "Submarine"'

An alert can be displayed instead of a notification

Does not take the sub-heading nor the sound tough.

With AppleScript:

display alert "Alert title" message "Your message text line here."

With terminal/bash and osascript:

osascript -e 'display alert "Alert title" message "Your message text line here."'

Add a line in bash for playing the sound after the alert line:

afplay /System/Library/Sounds/Hero.aiff

Add same line in AppleScript, letting shell script do the work:

do shell script ("afplay /System/Library/Sounds/Hero.aiff")

List of macOS built in sounds to choose from here.

Paraphrased from a handy article on terminal and applescript notifications.

Remove leading comma from a string

You can use directly replace function on javascript with regex or define a help function as in php ltrim(left) and rtrim(right):

1) With replace:

var myArray = ",'first string','more','even more'".replace(/^\s+/, '').split(/'?,?'/);

2) Help functions:

if (!String.prototype.ltrim) String.prototype.ltrim = function() {
    return this.replace(/^\s+/, '');
};
if (!String.prototype.rtrim) String.prototype.rtrim = function() {
    return this.replace(/\s+$/, '');
};
var myArray = ",'first string','more','even more'".ltrim().split(/'?,?'/).filter(function(el) {return el.length != 0});;

You can do and other things to add parameter to the help function with what you want to replace the char, etc.

Easiest way to toggle 2 classes in jQuery

If your element exposes class A from the start, you can write:

$(element).toggleClass("A B");

This will remove class A and add class B. If you do that again, it will remove class B and reinstate class A.

If you want to match the elements that expose either class, you can use a multiple class selector and write:

$(".A, .B").toggleClass("A B");

New og:image size for Facebook share?

Facebook.com og:image is 325x325 (1:1 aspect ratio, square)

https://www.facebook.com/images/fb_icon_325x325.png

Difference between Inheritance and Composition

Inheritence means reusing the complete functionality of a class, Here my class have to use all the methods of the super class and my class will be titely coupled with the super class and code will be duplicated in both the classes in case of inheritence.

But we can overcome from all these problem when we use composition to talk with another class . composition is declaring an attribute of another class into my class to which we want to talk. and what functionality we want from that class we can get by using that attribute.

Getting an option text/value with JavaScript

In jquery you could try this $("#select_id>option:selected").text()

How do I REALLY reset the Visual Studio window layout?

I close them, but they always come back

When you say "they always come back" do you mean "next time you restart Visual Studio" or "immediately"?

One quirk of Visual Studio (at least VS2005) is that settings aren't saved until you exit. That means that if VS crashes at all while you are using it, any layout changes you made will be lost. The way around this is to always gracefully exit when you have set up everything like you want it to be.

Not sure if this will help your particular situation though.

React hooks useState Array

To expand on Ryan's answer:

Whenever setStateValues is called, React re-renders your component, which means that the function body of the StateSelector component function gets re-executed.

React docs:

setState() will always lead to a re-render unless shouldComponentUpdate() returns false.

Essentially, you're setting state with:

setStateValues(allowedState);

causing a re-render, which then causes the function to execute, and so on. Hence, the loop issue.

To illustrate the point, if you set a timeout as like:

  setTimeout(
    () => setStateValues(allowedState),
    1000
  )

Which ends the 'too many re-renders' issue.

In your case, you're dealing with a side-effect, which is handled with UseEffectin your component functions. You can read more about it here.

javascript scroll event for iPhone/iPad?

For iOS you need to use the touchmove event as well as the scroll event like this:

document.addEventListener("touchmove", ScrollStart, false);
document.addEventListener("scroll", Scroll, false);

function ScrollStart() {
    //start of scroll event for iOS
}

function Scroll() {
    //end of scroll event for iOS
    //and
    //start/end of scroll event for other browsers
}

Optimistic vs. Pessimistic locking

In addition to what's been said already:

  • It should be said that optimistic locking tends to improve concurrency at the expense of predictability.
  • Pessimistic locking tends to reduce concurrency, but is more predictable. You pay your money, etc ...

Printing a java map Map<String, Object> - How?

You may use Map.entrySet() method:

for (Map.Entry entry : objectSet.entrySet())
{
    System.out.println("key: " + entry.getKey() + "; value: " + entry.getValue());
}

Change header text of columns in a GridView

I Think this Works:

 testGV.HeaderRow.Cells[0].Text="Date"

Angular 2 How to redirect to 404 or other path if the path does not exist

My preferred option on 2.0.0 and up is to create a 404 route and also allow a ** route path to resolve to the same component. This allows you to log and display more information about the invalid route rather than a plain redirect which can act to hide the error.

Simple 404 example:

{ path '/', component: HomeComponent },
// All your other routes should come first    
{ path: '404', component: NotFoundComponent },
{ path: '**', component: NotFoundComponent }

To display the incorrect route information add in import to router within NotFoundComponent:

import { Router } from '@angular/router';

Add it to the constructior of NotFoundComponent:

constructor(public router: Router) { }

Then you're ready to reference it from your HTML template e.g.

The page <span style="font-style: italic">{{router.url}}</span> was not found.

Creating multiple log files of different content with log4j

This should get you started:

log4j.rootLogger=QuietAppender, LoudAppender, TRACE
# setup A1
log4j.appender.QuietAppender=org.apache.log4j.RollingFileAppender
log4j.appender.QuietAppender.Threshold=INFO
log4j.appender.QuietAppender.File=quiet.log
...


# setup A2
log4j.appender.LoudAppender=org.apache.log4j.RollingFileAppender
log4j.appender.LoudAppender.Threshold=DEBUG
log4j.appender.LoudAppender.File=loud.log
...

log4j.logger.com.yourpackage.yourclazz=TRACE

JPA COUNT with composite primary key query not working

Use count(d.ertek) or count(d.id) instead of count(d). This can be happen when you have composite primary key at your entity.

Regex match everything after question mark?

With the positive lookbehind technique:

(?<=\?).*

(We're searching for a text preceded by a question mark here)

Input: derpderp?mystring blahbeh
Output: mystring blahbeh

Example

Basically the ?<= is a group construct, that requires the escaped question-mark, before any match can be made.

They perform really well, but not all implementations support them.

get and set in TypeScript

TypeScript uses getter/setter syntax that is like ActionScript3.

class foo {
    private _bar: boolean = false;
    get bar(): boolean {
        return this._bar;
    }
    set bar(value: boolean) {
        this._bar = value;
    }
}

That will produce this JavaScript, using the ECMAScript 5 Object.defineProperty() feature.

var foo = (function () {
    function foo() {
        this._bar = false;
    }
    Object.defineProperty(foo.prototype, "bar", {
        get: function () {
            return this._bar;
        },
        set: function (value) {
            this._bar = value;
        },
        enumerable: true,
        configurable: true
    });
    return foo;
})();

So to use it,

var myFoo = new foo();
if(myFoo.bar) {         // calls the getter
    myFoo.bar = false;  // calls the setter and passes false
}

However, in order to use it at all, you must make sure the TypeScript compiler targets ECMAScript5. If you are running the command line compiler, use --target flag like this;

tsc --target ES5

If you are using Visual Studio, you must edit your project file to add the flag to the configuration for the TypeScriptCompile build tool. You can see that here:

As @DanFromGermany suggests below, if your are simply reading and writing a local property like foo.bar = true, then having a setter and getter pair is overkill. You can always add them later if you need to do something, like logging, whenever the property is read or written.

android.view.InflateException: Binary XML file: Error inflating class fragment

I think the basic problem is with "android:targetSdkVersion" which is defined in AndroidManifest.xml. In my case, the initial value which I have defined as:

android:targetSdkVersion=16

I changed it to:

android:targetSdkVersion=22

which resolved my all of the error. So, setting up the correct "targetSdkVersion" is also important before building an android app.

submit form on click event using jquery

Using jQuery button click

$('#button_id').on('click',function(){
     $('#form_id').submit();
 });

Swing vs JavaFx for desktop applications

I don't think there's any one right answer to this question, but my advice would be to stick with SWT unless you are encountering severe limitations that require such a massive overhaul.

Also, SWT is actually newer and more actively maintained than Swing. (It was originally developed as a replacement for Swing using native components).

Extract substring using regexp in plain bash

    echo "US/Central - 10:26 PM (CST)" | sed -n "s/^.*-\s*\(\S*\).*$/\1/p"

-n      suppress printing
s       substitute
^.*     anything at the beginning
-       up until the dash
\s*     any space characters (any whitespace character)
\(      start capture group
\S*     any non-space characters
\)      end capture group
.*$     anything at the end
\1      substitute 1st capture group for everything on line
p       print it

Tomcat Servlet: Error 404 - The requested resource is not available

try this (if the Java EE V6)

package crunch;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
@WebServlet(name="hello",urlPatterns={"/hello"})
public class HelloWorld extends HttpServlet {
  public void doGet(HttpServletRequest request,
                    HttpServletResponse response)
      throws ServletException, IOException {
    PrintWriter out = response.getWriter();
    out.println("Hello World");
  }
}

now reach the servlet by http://127.0.0.1:8080/yourapp/hello

where 8080 is default tomcat port, and yourapp is the context name of your applciation

Error "There is already an open DataReader associated with this Command which must be closed first" when using 2 distinct commands

Try to combine the query, it will run much faster than executing an additional query per row. Ik don't like the string[] you're using, i would create a class for holding the information.

    public List<string[]> get_dados_historico_verificacao_email_WEB(string email)
    {
        List<string[]> historicos = new List<string[]>();

        using (SqlConnection conexao = new SqlConnection("ConnectionString"))
        {
            string sql =
                @"SELECT    *, 
                            (   SELECT      COUNT(e.cd_historico_verificacao_email) 
                                FROM        emails_lidos e 
                                WHERE       e.cd_historico_verificacao_email = a.nm_email ) QT
                  FROM      historico_verificacao_email a
                  WHERE     nm_email = @email
                  ORDER BY  dt_verificacao_email DESC, 
                            hr_verificacao_email DESC";

            using (SqlCommand com = new SqlCommand(sql, conexao))
            {
                com.Parameters.Add("email", SqlDbType.VarChar).Value = email;

                SqlDataReader dr = com.ExecuteReader();

                while (dr.Read())
                {
                    string[] dados_historico = new string[6];
                    dados_historico[0] = dr["nm_email"].ToString();
                    dados_historico[1] = dr["dt_verificacao_email"].ToString();
                    dados_historico[1] = dados_historico[1].Substring(0, 10);
                    //System.Windows.Forms.MessageBox.Show(dados_historico[1]);
                    dados_historico[2] = dr["hr_verificacao_email"].ToString();
                    dados_historico[3] = dr["ds_tipo_verificacao"].ToString();
                    dados_historico[4] = dr["QT"].ToString();
                    dados_historico[5] = dr["cd_login_usuario"].ToString();

                    historicos.Add(dados_historico);
                }
            }
        }
        return historicos;
    }

Untested, but maybee gives some idea.

Oracle SELECT TOP 10 records

You'll need to put your current query in subquery as below :

SELECT * FROM (
  SELECT DISTINCT 
  APP_ID, 
  NAME, 
  STORAGE_GB, 
  HISTORY_CREATED, 
  TO_CHAR(HISTORY_DATE, 'DD.MM.YYYY') AS HISTORY_DATE  
  FROM HISTORY WHERE 
    STORAGE_GB IS NOT NULL AND 
      APP_ID NOT IN (SELECT APP_ID FROM HISTORY WHERE TO_CHAR(HISTORY_DATE, 'DD.MM.YYYY') ='06.02.2009')
  ORDER BY STORAGE_GB DESC )
WHERE ROWNUM <= 10

Oracle applies rownum to the result after it has been returned.
You need to filter the result after it has been returned, so a subquery is required. You can also use RANK() function to get Top-N results.

For performance try using NOT EXISTS in place of NOT IN. See this for more.

Cant get text of a DropDownList in code - can get value but not text

add list using

<asp:ListItem Value="United States" Text="Canada"></asp:ListItem>

and then try

DropDownList1.SelectedItem.Text

I found your mistake.

<asp:ListItem>United States</asp:ListItem> 

change this to

<asp:ListItem>United States1</asp:ListItem> 

Then you will got the actual value.

What was the issue is, there are two same values in your dropdown, when page postback, it take first value as selected and give the result accordingly. if you noticed when after postback United State Value is selected

javascript object max size limit

There is no such limit on the string length. To be certain, I just tested to create a string containing 60 megabyte.

The problem is likely that you are sending the data in a GET request, so it's sent in the URL. Different browsers have different limits for the URL, where IE has the lowest limist of about 2 kB. To be safe, you should never send more data than about a kilobyte in a GET request.

To send that much data, you have to send it in a POST request instead. The browser has no hard limit on the size of a post, but the server has a limit on how large a request can be. IIS for example has a default limit of 4 MB, but it's possible to adjust the limit if you would ever need to send more data than that.

Also, you shouldn't use += to concatenate long strings. For each iteration there is more and more data to move, so it gets slower and slower the more items you have. Put the strings in an array and concatenate all the items at once:

var items = $.map(keys, function(item, i) {
  var value = $("#value" + (i+1)).val().replace(/"/g, "\\\"");
  return
    '{"Key":' + '"' + Encoder.htmlEncode($(this).html()) + '"' + ",'+
    '" + '"Value"' + ':' + '"' + Encoder.htmlEncode(value) + '"}';
});
var jsonObj =
  '{"code":"' + code + '",'+
  '"defaultfile":"' + defaultfile + '",'+
  '"filename":"' + currentFile + '",'+
  '"lstResDef":[' + items.join(',') + ']}';

php is null or empty?

Use empty - http://php.net/manual/en/function.empty.php.

Example:

$a = '';
if(empty($a)) {
    echo 'is empty';
}

Save Screen (program) output to a file

There is a command line option for logging. The output is saved to screenlog.n file, where n is a number of the screen. From man pages of screen:

‘-L’ Tell screen to turn on automatic output logging for the windows.

How to extract .war files in java? ZIP vs JAR

If you look at the JarFile API you'll see that it's a subclass of the ZipFile class.

The jar-specific classes mostly just add jar-specific functionality, like direct support for manifest file attributes and so on.

It's OOP "in action"; since jar files are zip files, the jar classes can use zip functionality and provide additional utility.

How do disable paging by swiping with finger in ViewPager but still be able to swipe programmatically?

In kotlin, we can solve this by creating a custom widget inheriting the ViewPager class and adding a flag value for controlling swipe behavior.

NoSwipePager.kt

class NoSwipePager(context: Context, attrs: AttributeSet) : ViewPager(context, attrs) {

    var pagingEnabled: Boolean = false

    override fun onTouchEvent(event: MotionEvent): Boolean {
        return if (this.pagingEnabled) {
            super.onTouchEvent(event)
        } else false
    }

    override fun onInterceptTouchEvent(event: MotionEvent): Boolean {
        return if (this.pagingEnabled) {
            super.onInterceptTouchEvent(event)
        } else false
    }
}

In xml

<your.package.NoSwipePager
    android:id="@+id/view_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_below="@id/tab_layout" />

Disable swiping programmatically. If kotlin-android-extensions plugin is applied in build.gradle, swiping can be disabled by writing below code.

view_pager.pagingEnabled = false

Otherwise we can disable swiping using code below:

val viewPager : ViewPager = findViewById(R.id.view_pager)
viewPager.pagingEnabled = false

Retrieve specific commit from a remote Git repository

If the requested commit is in the pull requests of the remote repo, you can get it by its ID:

# Add the remote repo path, let's call it 'upstream':
git remote add upstream https://github.com/repo/project.git

# checkout the pull ID, for example ID '60':
git fetch upstream pull/60/head && git checkout FETCH_HEAD

How to get post slug from post in WordPress?

Here is most advanced and updated version what cover many cases:

if(!function_exists('the_slug')):
    function the_slug($post_id=false, $echo=true) {
        global $product, $page;

        if(is_numeric($post_id) && $post_id == intval($post_id)) {} else {
            if(!is_object($post_id)){}else if(property_exists($post_id, 'ID')){
                $post_id = $post_id->ID;
            }
            if(empty($post_id) && property_exists($product, 'ID')) $post_id = $product->ID;
            if(empty($post_id)) $post_id =  get_the_ID();

            if(empty($post_id) && property_exists($page, 'ID')) $post_id =  $page->ID;
        }

        if(!empty($post_id))
            $slug = basename(get_permalink($post_id));
        else
            $slug = basename(get_permalink());
        do_action('before_slug', $slug);
        $slug = apply_filters('slug_filter', $slug);
        if( $echo ) echo $slug;
        do_action('after_slug', $slug);
        return $slug;
      }
endif;

This is collections from the best answers and few my updates.

Turning off some legends in a ggplot

You can use guide=FALSE in scale_..._...() to suppress legend.

For your example you should use scale_colour_continuous() because length is continuous variable (not discrete).

(p3 <- ggplot(mov, aes(year, rating, colour = length, shape = mpaa)) +
   scale_colour_continuous(guide = FALSE) +
   geom_point()
)

Or using function guides() you should set FALSE for that element/aesthetic that you don't want to appear as legend, for example, fill, shape, colour.

p0 <- ggplot(mov, aes(year, rating, colour = length, shape = mpaa)) +
  geom_point()    
p0+guides(colour=FALSE)

UPDATE

Both provided solutions work in new ggplot2 version 2.0.0 but movies dataset is no longer present in this library. Instead you have to use new package ggplot2movies to check those solutions.

library(ggplot2movies)
data(movies)
mov <- subset(movies, length != "")

Iterate Multi-Dimensional Array with Nested Foreach Statement

Two ways:

  1. Define the array as a jagged array, and use nested foreachs.
  2. Define the array normally, and use foreach on the entire thing.

Example of #2:

int[,] arr = { { 1, 2 }, { 3, 4 } };
foreach(int a in arr)
    Console.Write(a);

Output will be 1234. ie. exactly the same as doing i from 0 to n, and j from 0 to n.

How do I copy the contents of one stream to another?

I use the following extension methods. They have optimized overloads for when one stream is a MemoryStream.

    public static void CopyTo(this Stream src, Stream dest)
    {
        int size = (src.CanSeek) ? Math.Min((int)(src.Length - src.Position), 0x2000) : 0x2000;
        byte[] buffer = new byte[size];
        int n;
        do
        {
            n = src.Read(buffer, 0, buffer.Length);
            dest.Write(buffer, 0, n);
        } while (n != 0);           
    }

    public static void CopyTo(this MemoryStream src, Stream dest)
    {
        dest.Write(src.GetBuffer(), (int)src.Position, (int)(src.Length - src.Position));
    }

    public static void CopyTo(this Stream src, MemoryStream dest)
    {
        if (src.CanSeek)
        {
            int pos = (int)dest.Position;
            int length = (int)(src.Length - src.Position) + pos;
            dest.SetLength(length); 

            while(pos < length)                
                pos += src.Read(dest.GetBuffer(), pos, length - pos);
        }
        else
            src.CopyTo((Stream)dest);
    }

Detect if an input has text in it using CSS -- on a page I am visiting and do not control?

There's actually a way to do this without javascript.

If you set an <input>'s required selector to true, you can check if there's text in it with the CSS :valid tag.

References:

MDN Docs
CSS Tricks

_x000D_
_x000D_
input {
  background: red;
}

input:valid {
  background: lightgreen;
}
_x000D_
<input type="text" required>
_x000D_
_x000D_
_x000D_

How to execute a shell script on a remote server using Ansible?

local_action runs the command on the local server, not on the servers you specify in hosts parameter.

Change your "Execute the script" task to

- name: Execute the script
  command: sh /home/test_user/test.sh

and it should do it.

You don't need to repeat sudo in the command line because you have defined it already in the playbook.

According to Ansible Intro to Playbooks user parameter was renamed to remote_user in Ansible 1.4 so you should change it, too

remote_user: test_user

So, the playbook will become:

---
- name: Transfer and execute a script.
  hosts: server
  remote_user: test_user
  sudo: yes
  tasks:
     - name: Transfer the script
       copy: src=test.sh dest=/home/test_user mode=0777

     - name: Execute the script
       command: sh /home/test_user/test.sh

How can I convert IPV6 address to IPV4 address?

The IPAddress Java library can accomplish what you are describing here.

IPv6 addresses are 16 bytes. Using that library, if you are starting with a 16-byte array you can construct the IPv6 address object:

IPv6Address addr = new IPv6Address(bytes); //bytes is byte[16]

From there you can check if the address is IPv4 mapped, IPv4 compatible, IPv4 translated, and so on (there are many possible ways IPv6 represents IPv4 addresses). In most cases, if an IPv6 address represents an IPv4 address, the ipv4 address is in the lower 4 bytes, and so you can get the derived IPv4 address as follows. Afterwards, you can convert back to bytes, which will be just 4 bytes for IPv4.

    if(addr.isIPv4Compatible() || addr.isIPv4Mapped()) {
        IPv4Address derivedIpv4Address = addr.getEmbeddedIPv4Address();
        byte ipv4Bytes[] = derivedIpv4Address.getBytes();
        ...
     }

The javadoc is available at the link.

CURL alternative in Python

Here's a simple example using urllib2 that does a basic authentication against GitHub's API.

import urllib2

u='username'
p='userpass'
url='https://api.github.com/users/username'

# simple wrapper function to encode the username & pass
def encodeUserData(user, password):
    return "Basic " + (user + ":" + password).encode("base64").rstrip()

# create the request object and set some headers
req = urllib2.Request(url)
req.add_header('Accept', 'application/json')
req.add_header("Content-type", "application/x-www-form-urlencoded")
req.add_header('Authorization', encodeUserData(u, p))
# make the request and print the results
res = urllib2.urlopen(req)
print res.read()

Furthermore if you wrap this in a script and run it from a terminal you can pipe the response string to 'mjson.tool' to enable pretty printing.

>> basicAuth.py | python -mjson.tool

One last thing to note, urllib2 only supports GET & POST requests.
If you need to use other HTTP verbs like DELETE, PUT, etc you'll probably want to take a look at PYCURL

Predicate Delegates in C#

If you're in VB 9 (VS2008), a predicate can be a complex function:

Dim list As New List(Of Integer)(New Integer() {1, 2, 3})
Dim newList = list.FindAll(AddressOf GreaterThanTwo)
...
Function GreaterThanTwo(ByVal item As Integer) As Boolean
    'do some work'
    Return item > 2
End Function

Or you can write your predicate as a lambda, as long as it's only one expression:

Dim list As New List(Of Integer)(New Integer() {1, 2, 3})
Dim newList = list.FindAll(Function(item) item > 2)

Servlet for serving static content

Judging from the example information above, I think this entire article is based on a bugged behavior in Tomcat 6.0.29 and earlier. See https://issues.apache.org/bugzilla/show_bug.cgi?id=50026. Upgrade to Tomcat 6.0.30 and the behavior between (Tomcat|Jetty) should merge.

Use jQuery to change a second select list based on the first select list option

All of these methods are great. I have found another simple resource that is a great example of creating a dynamic form using "onchange" with AJAX.

http://www.w3schools.com/php/php_ajax_database.asp

I simply modified the text table output to anther select dropdown populated based on the selection of the first drop down. For my application a user will select a state then the second dropdown will be populated with the cities for the selected state. Much like the JSON example above but with php and mysql.

How to detect the physical connected state of a network cable/connector?

Somehow if you want to check if the ethernet cable plugged in linux after the commend:" ifconfig eth0 down". I find a solution: use the ethtool tool.

#ethtool -t eth0
The test result is PASS
The test extra info:
Register test  (offline)         0
Eeprom test    (offline)         0
Interrupt test (offline)         0
Loopback test  (offline)         0
Link test   (on/offline)         0

if cable is connected,link test is 0,otherwise is 1.

HTML+CSS: How to force div contents to stay in one line?

Your HTML code: <div>Stack Overflow is the BEST !!!</div>

CSS:

div {
    width: 100px;
    white-space:nowrap;
    overflow:hidden;
    text-overflow:ellipsis;
}

Now the result should be:

Stack Overf...

Transparent CSS background color

now you can use rgba in CSS properties like this:

.class {
    background: rgba(0,0,0,0.5);
}

0.5 is the transparency, change the values according to your design.

Live demo http://jsfiddle.net/EeAaB/

more info http://css-tricks.com/rgba-browser-support/

Array of arrays (Python/NumPy)

You'll have problems creating lists without commas. It shouldn't be too hard to transform your data so that it uses commas as separating character.

Once you have commas in there, it's a relatively simple list creation operations:

array1 = [1,2,3]
array2 = [4,5,6]

array3 = [array1, array2]

array4 = [7,8,9]
array5 = [10,11,12]

array3 = [array3, [array4, array5]]

When testing we get:

print(array3)

[[[1, 2, 3], [4, 5, 6]], [[7, 8, 9], [10, 11, 12]]]

And if we test with indexing it works correctly reading the matrix as made up of 2 rows and 2 columns:

array3[0][1]
[4, 5, 6]

array3[1][1]
[10, 11, 12]

Hope that helps.

PackagesNotFoundError: The following packages are not available from current channels:

Even i was facing the same problem ,but solved it by

conda install -c conda-forge pysoundfile

while importing it

import soundfile 

Make a DIV fill an entire table cell

I had to set a fake height to the <tr> and height: inherit for <td>s

tr has height: 1px (it's ignored anyway)

Then set the td height: inherit

Then set the div to height: 100%

This worked for me in IE edge and Chrome:

_x000D_
_x000D_
<table style="width:200px;">
    <tr style="height: 1px;">
        <td style="height: inherit; border: 1px solid #000; width: 100px;">
            <div>
              Something big with multi lines and makes table bigger
            </div>
        </td>
        <td style="height: inherit; border: 1px solid #000; width: 100px;">
            <div style="background-color: red; height: 100%;">
                full-height div
            </div>
        </td>
    </tr>
</table>
_x000D_
_x000D_
_x000D_

What does "collect2: error: ld returned 1 exit status" mean?

Try running task manager to determine if your program is still running.

If it is running then stop it and run it again. the [Error] ld returned 1 exit status will not come back

jQuery click / toggle between two functions

one line solution: basic idea:

$('sth').click(function () {
    let COND = $(this).propery == 'cond1' ? 'cond2' : 'cond1';
    doSomeThing(COND);
})

examples on jsfiddle

example 1, changing innerHTML of an element in a toggle-mode:

$('#clickTest1').click(function () {
    $(this).html($(this).html() == 'click Me' ? 'clicked' : 'click Me');
});

example 2, toggling displays between "none" and "inline-block":

$('#clickTest2, #clickTest2 > span').click(function () {
    $(this).children().css('display', $(this).children().css('display') == 'inline-block' ? 'none' : 'inline-block');
});

How to call a PHP file from HTML or Javascript


How to make a button call PHP?

I don't care if the page reloads or displays the results immediately;

Good!

Note: If you don't want to refresh the page see "Ok... but how do I Use Ajax anyway?" below.

I just want to have a button on my website make a PHP file run.

That can be done with a form with a single button:

<form action="">
  <input type="submit" value="my button"/>
</form>

That's it.

Pretty much. Also note that there are cases where ajax is really the way to go.

That depends on what you want. In general terms you only need ajax when you want to avoid realoading the page. Still you have said that you don't care about that.


Why I cannot call PHP directly from JavaScript?

If I can write the code inside HTML just fine, why can't I just reference the file for it in there or make a simple call for it in Javascript?

Because the PHP code is not in the HTML just fine. That's an illusion created by the way most server side scripting languages works (including PHP, JSP, and ASP). That code only exists on the server, and it is no reachable form the client (the browser) without a remote call of some sort.

You can see evidence of this if you ask your browser to show the source code of the page. There you will not see the PHP code, that is because the PHP code is not send to the client, therefore it cannot be executed from the client. That's why you need to do a remote call to be able to have the client trigger the execution of PHP code.

If you don't use a form (as shown above) you can do that remote call from JavaScript with a little thing called Ajax. You may also want to consider if what you want to do in PHP can be done directly in JavaScript.


How to call another PHP file?

Use a form to do the call. You can have it to direct the user to a particlar file:

<form action="myphpfile.php">
  <input type="submit" value="click on me!">
</form>

The user will end up in the page myphpfile.php. To make it work for the current page, set action to an empty string (which is what I did in the example I gave you early).

I just want to link it to a PHP file that will create the permanent blog post on the server so that when I reload the page, the post is still there.

You want to make an operation on the server, you should make your form have the fields you need (even if type="hidden" and use POST):

<form action="" method="POST">
  <input type="text" value="default value, you can edit it" name="myfield">
  <input type="submit" value = "post">
</form>

What do I need to know about it to call a PHP file that will create a text file on a button press?

see: How to write into a file in PHP.


How do you recieve the data from the POST in the server?

I'm glad you ask... Since you are a newb begginer, I'll give you a little template you can follow:

<?php
    if ($_SERVER['REQUEST_METHOD'] === 'POST')
    {
        //Ok we got a POST, probably from a FORM, read from $_POST.
        var_dump($_PSOT); //Use this to see what info we got!
    }
    else
    {
       //You could assume you got a GET
       var_dump($_GET); //Use this to see what info we got!
    }
 ?>
 <!DOCTYPE html>
 <html lang="en">
   <head>
     <meta char-set="utf-8">
     <title>Page title</title>
   </head>
   <body>
     <form action="" method="POST">
       <input type="text" value="default value, you can edit it" name="myfield">
       <input type="submit" value = "post">
     </form>
   </body>
 </html>

Note: you can remove var_dump, it is just for debugging purposes.


How do I...

I know the next stage, you will be asking how to:

  1. how to pass variables form a PHP file to another?
  2. how to remember the user / make a login?
  3. how to avoid that anoying message the appears when you reload the page?

There is a single answer for that: Sessions.

I'll give a more extensive template for Post-Redirect-Get

<?php
    if ($_SERVER['REQUEST_METHOD'] === 'POST')
    {
        var_dump($_PSOT);
        //Do stuff...
        //Write results to session
        session_start();
        $_SESSION['stuff'] = $something;
        //You can store stuff such as the user ID, so you can remeember him.
        //redirect:
        header('Location: ', true, 303);
        //The redirection will cause the browser to request with GET
        //The results of the operation are in the session variable
        //It has empty location because we are redirecting to the same page
        //Otherwise use `header('Location: anotherpage.php', true, 303);`
        exit();
    }
    else
    {
        //You could assume you got a GET
        var_dump($_GET); //Use this to see what info we got!
        //Get stuff from session
        session_start();
        if (array_key_exists('stuff', $_SESSION))
        {
           $something = $_SESSION['stuff'];
           //we got stuff
           //later use present the results of the operation to the user.
        }
        //clear stuff from session:
        unset($_SESSION['stuff']);
        //set headers
        header('Content-Type: text/html; charset=utf-8');
        //This header is telling the browser what are we sending.
        //And it says we are sending HTML in UTF-8 encoding
    }
 ?>
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta char-set="utf-8">
    <title>Page title</title>
  </head>
  <body>
    <?php if (isset($something)){ echo '<span>'.$something.'</span>'}?>;
    <form action="" method="POST">
      <input type="text" value="default value, you can edit it" name="myfield">
      <input type="submit" value = "post">
    </form>
  </body>
</html>

Please look at php.net for any function call you don't recognize. Also - if you don't have already - get a good tutorial on HTML5.

Also, use UTF-8 because UTF-8!


Notes:

I'm making a simple blog site for myself and I've got the code for the site and the javascript that can take the post I write in a textarea and display it immediately.

If are you using a CMS (Codepress, Joomla, Drupal... etc)? That make put some contraints on how you got to do things.

Also, if you are using a framework, you should look at their documentation or ask at their forum/mailing list/discussion page/contact or try to ask the authors.


Ok... but how do I Use Ajax anyway?

Well... Ajax is made easy by some JavaScript libraries. Since you are a begginer, I'll recomend jQuery.

So, let's send something to the server via Ajax with jQuery, I'll use $.post instead of $.ajax for this example.

<?php
    if ($_SERVER['REQUEST_METHOD'] === 'POST')
    {
        var_dump($_PSOT);
        header('Location: ', true, 303);
        exit();
    }
    else
    {
        var_dump($_GET);
        header('Content-Type: text/html; charset=utf-8');
    }
 ?>
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta char-set="utf-8">
    <title>Page title</title>
    <script>
        function ajaxmagic()
        {
            $.post(                             //call the server
                "test.php",                     //At this url
                {
                    field: "value",
                    name: "John"
                }                               //And send this data to it
            ).done(                             //And when it's done
                function(data)
                {
                    $('#fromAjax').html(data);  //Update here with the response
                }
            );
        }
    </script>
  </head>
  <body>
    <input type="button" value = "use ajax", onclick="ajaxmagic()">
    <span id="fromAjax"></span>
  </body>
</html>

The above code will send a POST request to the page test.php.

Note: You can mix sessions with ajax and stuff if you want.


How do I...

  1. How do I connect to the database?
  2. How do I prevent SQL injection?
  3. Why shouldn't I use Mysql_* functions?

... for these or any other, please make another questions. That's too much for this one.

How to include "zero" / "0" results in COUNT aggregate?

To change even less on your original query, you can turn your join into a RIGHT join

SELECT person.person_id, COUNT(appointment.person_id) AS "number_of_appointments"
FROM appointment
RIGHT JOIN person ON person.person_id = appointment.person_id
GROUP BY person.person_id;

This just builds on the selected answer, but as the outer join is in the RIGHT direction, only one word needs to be added and less changes. - Just remember that it's there and can sometimes make queries more readable and require less rebuilding.

How to check if a Unix .tar.gz file is a valid file without uncompressing?

These are all very sub-optimal solutions. From the GZIP spec

ID2 (IDentification 2)
These have the fixed values ID1 = 31 (0x1f, \037), ID2 = 139 (0x8b, \213), to identify the file as being in gzip format.

Has to be coded into whatever language you're using.

How to set a default value with Html.TextBoxFor?

you can try this

<%= Html.TextBoxFor(x => x.Age, new { @Value = "0"}) %>

How to know if a DateTime is between a DateRange in C#

Usually I create Fowler's Range implementation for such things.

public interface IRange<T>
{
    T Start { get; }
    T End { get; }
    bool Includes(T value);
    bool Includes(IRange<T> range);
}

public class DateRange : IRange<DateTime>         
{
    public DateRange(DateTime start, DateTime end)
    {
        Start = start;
        End = end;
    }

    public DateTime Start { get; private set; }
    public DateTime End { get; private set; }

    public bool Includes(DateTime value)
    {
        return (Start <= value) && (value <= End);
    }

    public bool Includes(IRange<DateTime> range)
    {
        return (Start <= range.Start) && (range.End <= End);
    }
}

Usage is pretty simple:

DateRange range = new DateRange(startDate, endDate);
range.Includes(date)

Remove NaN from pandas series

If you have a pandas serie with NaN, and want to remove it (without loosing index):

serie = serie.dropna()

# create data for example
data = np.array(['g', 'e', 'e', 'k', 's']) 
ser = pd.Series(data)
ser.replace('e', np.NAN)
print(ser)

0      g
1    NaN
2    NaN
3      k
4      s
dtype: object

# the code
ser = ser.dropna()
print(ser)

0    g
3    k
4    s
dtype: object

Date validation with ASP.NET validator

I think the following is the easiest way to do it.

<asp:TextBox ID="DateControl" runat="server" Visible="False"></asp:TextBox>
<asp:RangeValidator ID ="rvDate" runat ="server" ControlToValidate="DateControl" ErrorMessage="Invalid Date" Type="Date" MinimumValue="01/01/1900" MaximumValue="01/01/2100" Display="Dynamic"></asp:RangeValidator>

How to detect if user select cancel InputBox VBA Excel

Following example uses InputBox method to validate user entry to unhide sheets: Important thing here is to use wrap InputBox variable inside StrPtr so it could be compared to '0' when user chose to click 'x' icon on the InputBox.

Sub unhidesheet()

Dim ws As Worksheet
Dim pw As String

pw = InputBox("Enter Password to Unhide Sheets:", "Unhide Data Sheets")
If StrPtr(pw) = 0 Then

   Exit Sub
ElseIf pw = NullString Then
   Exit Sub
ElseIf pw = 123456 Then
    For Each ws In ThisWorkbook.Worksheets
        ws.Visible = xlSheetVisible
    Next
End If
End Sub

LoDash: Get an array of values from an array of object properties

Since version v4.x you should use _.map:

_.map(users, 'id'); // [12, 14, 16, 18]

this way it is corresponds to native Array.prototype.map method where you would write (ES2015 syntax):

users.map(user => user.id); // [12, 14, 16, 18]

Before v4.x you could use _.pluck the same way:

_.pluck(users, 'id'); // [12, 14, 16, 18]

How can I trigger the click event of another element in ng-click using angularjs?

for jqLite just use triggerHandler with event name, To simulate a "click" try:

_x000D_
_x000D_
angular.element("tr").triggerHandler("click");
_x000D_
_x000D_
_x000D_

Here's the list of jQLite commands

Override devise registrations controller

You can generate views and controllers for devise customization.

Use

rails g devise:controllers users -c=registrations

and

rails g devise:views 

It will copy particular controllers and views from gem to your application.

Next, tell the router to use this controller:

devise_for :users, :controllers => {:registrations => "users/registrations"}

JavaScript string encryption and decryption?

The existing answers which leverage SJCL, CryptoJS, and/or WebCrypto aren't necessarily wrong but they're not as safe as you might initially suspect. Generally you want to use libsodium. First I'll explain why, then how.

Why Not SJCL, CryptoJS, WebCrypto, etc.?

Short answer: In order for your encryption to actually be secure, these libraries expect you to make too many choices e.g. the block cipher mode (CBC, CTR, GCM; if you can't tell which of the three I just listed is secure to use and under what constraints, you shouldn't be burdened with this sort of choice at all).

Unless your job title is cryptography engineer, the odds are stacked against you implementing it securely.

Why to Avoid CryptoJS?

CryptoJS offers a handful of building blocks and expects you to know how to use them securely. It even defaults to CBC mode (archived).

Why is CBC mode bad?

Read this write-up on AES-CBC vulnerabilities.

Why to Avoid WebCrypto?

WebCrypto is a potluck standard, designed by committee, for purposes that are orthogonal to cryptography engineering. Specifically, WebCrypto was meant to replace Flash, not provide security.

Why to Avoid SJCL?

SJCL's public API and documentation begs users to encrypt data with a human-remembered password. This is rarely, if ever, what you want to do in the real world.

Additionally: Its default PBKDF2 round count is roughly 86 times as small as you want it to be. AES-128-CCM is probably fine.

Out of the three options above, SJCL is the least likely to end in tears. But there are better options available.

Why is Libsodium Better?

You don't need to choose between a menu of cipher modes, hash functions, and other needless options. You'll never risk screwing up your parameters and removing all security from your protocol.

Instead, libsodium just gives you simple options tuned for maximum security and minimalistic APIs.

  • crypto_box() / crypto_box_open() offer authenticated public-key encryption.
    • The algorithm in question combines X25519 (ECDH over Curve25519) and XSalsa20-Poly1305, but you don't need to know (or even care) about that to use it securely
  • crypto_secretbox() / crypto_secretbox_open() offer shared-key authenticated encryption.
    • The algorithm in question is XSalsa20-Poly1305, but you don't need to know/care

Additionally, libsodium has bindings in dozens of popular programming languages, so it's very likely that libsodium will just work when trying to interoperate with another programming stack. Also, libsodium tends to be very fast without sacrificing security.

How to Use Libsodium in JavaScript?

First, you need to decide one thing:

  1. Do you just want to encrypt/decrypt data (and maybe still somehow use the plaintext in database queries securely) and not worry about the details? Or...
  2. Do you need to implement a specific protocol?

If you selected the first option, get CipherSweet.js.

The documentation is available online. EncryptedField is sufficient for most use cases, but the EncryptedRow and EncryptedMultiRows APIs may be easier if you have a lot of distinct fields you want to encrypt.

With CipherSweet, you don't need to even know what a nonce/IV is to use it securely.

Additionally, this handles int/float encryption without leaking facts about the contents through ciphertext size.

Otherwise, you'll want sodium-plus, which is a user-friendly frontend to various libsodium wrappers. Sodium-Plus allows you to write performant, asynchronous, cross-platform code that's easy to audit and reason about.

To install sodium-plus, simply run...

npm install sodium-plus

There is currently no public CDN for browser support. This will change soon. However, you can grab sodium-plus.min.js from the latest Github release if you need it.

_x000D_
_x000D_
const { SodiumPlus } = require('sodium-plus');_x000D_
let sodium;_x000D_
_x000D_
(async function () {_x000D_
    if (!sodium) sodium = await SodiumPlus.auto();_x000D_
    let plaintext = 'Your message goes here';_x000D_
    let key = await sodium.crypto_secretbox_keygen();_x000D_
    let nonce = await sodium.randombytes_buf(24);_x000D_
    let ciphertext = await sodium.crypto_secretbox(_x000D_
        plaintext,_x000D_
        nonce,_x000D_
        key    _x000D_
    );_x000D_
    console.log(ciphertext.toString('hex'));_x000D_
_x000D_
    let decrypted = await sodium.crypto_secretbox_open(_x000D_
        ciphertext,_x000D_
        nonce,_x000D_
        key_x000D_
    );_x000D_
_x000D_
    console.log(decrypted.toString());_x000D_
})();
_x000D_
_x000D_
_x000D_

The documentation for sodium-plus is available on Github.

If you'd like a step-by-step tutorial, this dev.to article has what you're looking for.

How to retrieve Jenkins build parameters using the Groovy API?

I've just got this working, so specifically, using the Groovy Postbuild plugin, you can do the following:

def paramText
def actionList = manager.build.getActions(hudson.model.ParametersAction)
if (actionList.size() != 0)
{
  def pA = actionList.get(0)
  paramText = pA.createVariableResolver(manager.build).resolve("MY_PARAM_NAME")
}

Remove duplicates from a list of objects based on property in Java 8

Another solution is to use a Predicate, then you can use this in any filter:

public static <T> Predicate<T> distinctBy(Function<? super T, ?> f) {
  Set<Object> objects = new ConcurrentHashSet<>();
  return t -> objects.add(f.apply(t));
}

Then simply reuse the predicate anywhere:

employees.stream().filter(distinctBy(e -> e.getId));

Note: in the JavaDoc of filter, which says it takes a stateless Predicte. Actually, this works fine even if the stream is parallel.


About other solutions:

1) Using .collect(Collectors.toConcurrentMap(..)).values() is a good solution, but it's annoying if you want to sort and keep the order.

2) stream.removeIf(e->!seen.add(e.getID())); is also another very good solution. But we need to make sure the collection implemented removeIf, for example it will throw exception if we construct the collection use Arrays.asList(..).

How can I decrease the size of Ratingbar?

In the RatingBar tag, add these two lines

style="@style/Widget.AppCompat.RatingBar.Small"
android:isIndicator="false"

Size of Matrix OpenCV

Note that apart from rows and columns there is a number of channels and type. When it is clear what type is, the channels can act as an extra dimension as in CV_8UC3 so you would address a matrix as

uchar a = M.at<Vec3b>(y, x)[i];

So the size in terms of elements of elementary type is M.rows * M.cols * M.cn

To find the max element one can use

Mat src;
double minVal, maxVal;
minMaxLoc(src, &minVal, &maxVal);

What are all codecs and formats supported by FFmpeg?

The formats and codecs supported by your build of ffmpeg can vary due the version, how it was compiled, and if any external libraries, such as libx264, were supported during compilation.

Formats (muxers and demuxers):

List all formats:

ffmpeg -formats

Display options specific to, and information about, a particular muxer:

ffmpeg -h muxer=matroska

Display options specific to, and information about, a particular demuxer:

ffmpeg -h demuxer=gif

Codecs (encoders and decoders):

List all codecs:

ffmpeg -codecs

List all encoders:

ffmpeg -encoders

List all decoders:

ffmpeg -decoders

Display options specific to, and information about, a particular encoder:

ffmpeg -h encoder=mpeg4

Display options specific to, and information about, a particular decoder:

ffmpeg -h decoder=aac

Reading the results

There is a key near the top of the output that describes each letter that precedes the name of the format, encoder, decoder, or codec:

$ ffmpeg -encoders
[…]
Encoders:
 V..... = Video
 A..... = Audio
 S..... = Subtitle
 .F.... = Frame-level multithreading
 ..S... = Slice-level multithreading
 ...X.. = Codec is experimental
 ....B. = Supports draw_horiz_band
 .....D = Supports direct rendering method 1
 ------
[…]
 V.S... mpeg4                MPEG-4 part 2

In this example V.S... indicates that the encoder mpeg4 is a Video encoder and supports Slice-level multithreading.

Also see

What is a codec and how does it differ from a format?

Why does NULL = NULL evaluate to false in SQL server

The answers here all seem to come from a CS perspective so I want to add one from a developer perspective.

For a developer NULL is very useful. The answers here say NULL means unknown, and maybe in CS theory that's true, don't remember, it's been a while. In actual development though, at least in my experience, that happens about 1% of the time. The other 99% it is used for cases where the value is not UNKNOWN but it is KNOWN TO BE ABSENT.

For example:

  • Client.LastPurchase, for a new client. It is not unknown, it is known that he hasn't made a purchase yet.

  • When using an ORM with a Table per Class Hierarchy mapping, some values are just not mapped for certain classes.

  • When mapping a tree structure a root will usually have Parent = NULL

  • And many more...

I'm sure most developers at some point wrote WHERE value = NULL, didn't get any results, and that's how they learned about IS NULL syntax. Just look how many votes this question and the linked ones have.

SQL Databases are a tool, and they should be designed the way which is easiest for their users to understand.

git ahead/behind info between master and branch?

First of all to see how many revisions you are behind locally, you should do a git fetch to make sure you have the latest info from your remote.

The default output of git status tells you how many revisions you are ahead or behind, but usually I find this too verbose:

$ git status
# On branch master
# Your branch and 'origin/master' have diverged,
# and have 2 and 1 different commit each, respectively.
#
nothing to commit (working directory clean)

I prefer git status -sb:

$ git status -sb
## master...origin/master [ahead 2, behind 1]

In fact I alias this to simply git s, and this is the main command I use for checking status.

To see the diff in the "ahead revisions" of master, I can exclude the "behind revisions" from origin/master:

git diff master..origin/master^

To see the diff in the "behind revisions" of origin/master, I can exclude the "ahead revisions" from master:

git diff origin/master..master^^

If there are 5 revisions ahead or behind it might be easier to write like this:

git diff master..origin/master~5
git diff origin/master..master~5

UPDATE

To see the ahead/behind revisions, the branch must be configured to track another branch. For me this is the default behavior when I clone a remote repository, and after I push a branch with git push -u remotename branchname. My version is 1.8.4.3, but it's been working like this as long as I remember.

As of version 1.8, you can set the tracking branch like this:

git branch --track test-branch

As of version 1.7, the syntax was different:

git branch --set-upstream test-branch

How to change color of the back arrow in the new material theme?

Here's how I did it in Material Components:

<style name="AppTheme" parent="Theme.MaterialComponents.DayNight.NoActionBar">
    <item name="drawerArrowStyle">@style/AppTheme.DrawerArrowToggle</item>
</style>

<style name="AppTheme.DrawerArrowToggle" parent="Widget.AppCompat.DrawerArrowToggle">
    <item name="color">@android:color/white</item>
</style>

How to force a list to be vertical using html css

Hope this is your structure:

   <ul> 
     <li>
        <div ><img.. /><p>text</p></div>
    </li>
     <li>
        <div ><img.. /><p>text</p></div>
    </li>
     <li>
        <div ><img.. /><p>text</p></div>
    </li>
   </ul> 

By default, it will be add one after another row:

-----
-----
-----

if you want to make it vertical, just add float left to li, give width and height, make sure that content will not break the width:

|  |  |
|  |  |

li
{
   display:block;
   float:left;
   width:300px; /* adjust */
   height:150px; /* adjust */
   padding: 5px; /*adjust*/
}

Problems using Maven and SSL behind proxy

I simply used new java version and it worked for me.

Get ID of element that called a function

Pass a reference to the element into the function when it is called:

<area id="nose" onmouseover="zoom(this);" />

<script>
  function zoom(ele) {
    var id = ele.id;

    console.log('area element id = ' + id);
  }
</script>

Synchronization vs Lock

Major difference between lock and synchronized:

  • with locks, you can release and acquire the locks in any order.
  • with synchronized, you can release the locks only in the order it was acquired.

What use is find_package() if you need to specify CMAKE_MODULE_PATH anyway?

You don't need to specify the module path per se. CMake ships with its own set of built-in find_package scripts, and their location is in the default CMAKE_MODULE_PATH.

The more normal use case for dependent projects that have been CMakeified would be to use CMake's external_project command and then include the Use[Project].cmake file from the subproject. If you just need the Find[Project].cmake script, copy it out of the subproject and into your own project's source code, and then you won't need to augment the CMAKE_MODULE_PATH in order to find the subproject at the system level.

Phone Number Validation MVC

Model

[Required(ErrorMessage = "You must provide a phone number")]
[Display(Name = "Home Phone")]
[DataType(DataType.PhoneNumber)]
[RegularExpression(@"^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$", ErrorMessage = "Not a valid phone number")]
public string PhoneNumber { get; set; }

View:

@Html.LabelFor(model => model.PhoneNumber)
@Html.EditorFor(model => model.PhoneNumber)
@Html.ValidationMessageFor(model => model.PhoneNumber)

How can I sort a dictionary by key?

Standard Python dictionaries are unordered. Even if you sorted the (key,value) pairs, you wouldn't be able to store them in a dict in a way that would preserve the ordering.

The easiest way is to use OrderedDict, which remembers the order in which the elements have been inserted:

In [1]: import collections

In [2]: d = {2:3, 1:89, 4:5, 3:0}

In [3]: od = collections.OrderedDict(sorted(d.items()))

In [4]: od
Out[4]: OrderedDict([(1, 89), (2, 3), (3, 0), (4, 5)])

Never mind the way od is printed out; it'll work as expected:

In [11]: od[1]
Out[11]: 89

In [12]: od[3]
Out[12]: 0

In [13]: for k, v in od.iteritems(): print k, v
   ....: 
1 89
2 3
3 0
4 5

Python 3

For Python 3 users, one needs to use the .items() instead of .iteritems():

In [13]: for k, v in od.items(): print(k, v)
   ....: 
1 89
2 3
3 0
4 5

Subprocess changing directory

just use os.chdir
Example:

>>> import os
>>> import subprocess
>>> # Lets Just Say WE want To List The User Folders
>>> os.chdir("/home/")
>>> subprocess.run("ls")
user1 user2 user3 user4

Dropdownlist validation in Asp.net Using Required field validator

I was struggling with this for a few days until I chanced on the issue when I had to build a new Dropdown. I had several DropDownList controls and attempted to get validation working with no luck. One was databound and the other was filled from the aspx page. I needed to drop the databound one and add a second manual list. In my case Validators failed if you built a dropdown like this and looked at any value (0 or -1) for either a required or compare validator:

<asp:DropDownList ID="DDL_Reason" CssClass="inputDropDown" runat="server">
<asp:ListItem>--Select--</asp:ListItem>                                                                                                
<asp:ListItem>Expired</asp:ListItem>                                                                                                
<asp:ListItem>Lost/Stolen</asp:ListItem>                                                                                                
<asp:ListItem>Location Change</asp:ListItem>                                                                                            
</asp:DropDownList>

However adding the InitialValue like this worked instantly for a compare Validator.

<asp:ListItem Text="-- Select --" Value="-1"></asp:ListItem>

Quickly create large file on a Windows system

I found an excellent utility that is configurable at https://github.com/acch/genfiles.

It fills the target file with random data, so there are no problems with sparse files, and for my purposes (testing compression algorithms) it gives a nice level of white noise.

How to include !important in jquery

For those times when you need to use jquery to set !important properties, here is a plugin I build that will allow you to do so.

$.fn.important = function(key, value) {
    var q = Object.assign({}, this.style)
    q[key] = `${value} !important`;
    $(this).css("cssText", Object.entries(q).filter(x => x[1]).map(([k, v]) => (`${k}: ${v}`)).join(';'));
};

$('div').important('color', 'red');

Data truncated for column?

However I get an error which doesn't make sense seeing as the column's data type was properly modified?

| Level | Code | Msg | Warn | 12 | Data truncated for column 'incoming_Cid' at row 1

You can often get this message when you are doing something like the following:

REPLACE INTO table2 (SELECT * FROM table1);

Resulted in our case in the following error:

SQL Exception: Data truncated for column 'level' at row 1

The problem turned out to be column misalignment that resulted in a tinyint trying to be stored in a datetime field or vice versa.

How to purge tomcat's cache when deploying a new .war file? Is there a config setting?

A little late for the party, here's how I do it

  1. Undeploy application from manager
  2. Shutdown tomcat using ./shutdown.sh
  3. Delete browser cache
  4. Delete the application from webapps, and from /work/Catalina/...
  5. Startup tomcat using ./startup.sh
  6. Copy the new version of the application into /webapps and start it.

How do I create a simple Qt console application in C++?

You could fire an event into the quit() slot of your application even without connect(). This way, the event-loop does at least one turn and should process the events within your main()-logic:

#include <QCoreApplication>
#include <QTimer>

int main(int argc, char *argv[])
{
    QCoreApplication app( argc, argv );

    // do your thing, once

    QTimer::singleShot( 0, &app, &QCoreApplication::quit );
    return app.exec();
}

Don't forget to place CONFIG += console in your .pro-file, or set consoleApplication: true in your .qbs Project.CppApplication.

__FILE__, __LINE__, and __FUNCTION__ usage in C++

Personally, I'm reluctant to use these for anything but debugging messages. I have done it, but I try not to show that kind of information to customers or end users. My customers are not engineers and are sometimes not computer savvy. I might log this info to the console, but, as I said, reluctantly except for debug builds or for internal tools. I suppose it does depend on the customer base you have, though.

What is the difference between DTR/DSR and RTS/CTS flow control?

The difference between them is that they use different pins. Seriously, that's it. The reason they both exist is that RTS/CTS wasn't supposed to ever be a flow control mechanism, originally; it was for half-duplex modems to coordinate who was sending and who was receiving. RTS and CTS got misused for flow control so often that it became standard.

disable horizontal scroll on mobile web

I've found this answer over here on stackoverflow which works perfectly for me:

use this in style

body {
    overflow-x: hidden;
    width: 100%;
}

Use this in head tag

<meta name="viewport" content="user-scalable=no, width=device-width, initial-scale=1.0" />
<meta name="apple-mobile-web-app-capable" content="yes" />

A slight addition of mine in case your body has padding (to prevent the device from scaling to the body content-box, and thus still adding a horizontal scrollbar):

body {
    overflow-x: hidden;
    width: 100%;
    -webkit-box-sizing: border-box;
       -moz-box-sizing: border-box;
            box-sizing: border-box;
}

How do you run a command as an administrator from the Windows command line?

:: ------- Self-elevating.bat --------------------------------------
@whoami /groups | find "S-1-16-12288" > nul && goto :admin
set "ELEVATE_CMDLINE=cd /d "%~dp0" & call "%~f0" %*"
findstr "^:::" "%~sf0">temp.vbs
cscript //nologo temp.vbs & del temp.vbs & exit /b

::: Set objShell = CreateObject("Shell.Application")
::: Set objWshShell = WScript.CreateObject("WScript.Shell")
::: Set objWshProcessEnv = objWshShell.Environment("PROCESS")
::: strCommandLine = Trim(objWshProcessEnv("ELEVATE_CMDLINE"))
::: objShell.ShellExecute "cmd", "/c " & strCommandLine, "", "runas"
:admin -------------------------------------------------------------

@echo off
echo Running as elevated user.
echo Script file : %~f0
echo Arguments   : %*
echo Working dir : %cd%
echo.
:: administrator commands here
:: e.g., run shell as admin
cmd /k

For a demo: self-elevating.bat "path with spaces" arg2 3 4 "another long argument"

And this is another version that does not require creating a temp file.

<!-- : --- Self-Elevating Batch Script ---------------------------
@whoami /groups | find "S-1-16-12288" > nul && goto :admin
set "ELEVATE_CMDLINE=cd /d "%~dp0" & call "%~f0" %*"
cscript //nologo "%~f0?.wsf" //job:Elevate & exit /b

-->
<job id="Elevate"><script language="VBScript">
  Set objShell = CreateObject("Shell.Application")
  Set objWshShell = WScript.CreateObject("WScript.Shell")
  Set objWshProcessEnv = objWshShell.Environment("PROCESS")
  strCommandLine = Trim(objWshProcessEnv("ELEVATE_CMDLINE"))
  objShell.ShellExecute "cmd", "/c " & strCommandLine, "", "runas"
</script></job>
:admin -----------------------------------------------------------

@echo off
echo Running as elevated user.
echo Script file : %~f0
echo Arguments   : %*
echo Working dir : %cd%
echo.
:: administrator commands here
:: e.g., run shell as admin
cmd /k

How to insert values into the database table using VBA in MS access

You can't run two SQL statements into one like you are doing.

You can't "execute" a select query.

db is an object and you haven't set it to anything: (e.g. set db = currentdb)

In VBA integer types can hold up to max of 32767 - I would be tempted to use Long.

You might want to be a bit more specific about the date you are inserting:

INSERT INTO Test (Start_Date) VALUES ('#" & format(InDate, "mm/dd/yyyy") & "#' );"

Dilemma: when to use Fragments vs Activities:

You are free to use one of those.
Basically, you have to evaluate which is the best one to your app. Think about how you will manage the business flow and how to store/manage data preferences.

Think about, how Fragments store garbage data. When you implement the fragment, you have a activity root to fill with fragment(s). So, if your trying to implement a lot of activities with too much fragments, you have to consider performance on your app, coz you're manipulating (coarsely speaks) two context lifecycle, remember the complexity.

Remember: should I use fragments? Why shouldn't I?

regards.

Change window location Jquery

If you want to use the back button, check this out. https://stackoverflow.com/questions/116446/what-is-the-best-back-button-jquery-plugin

Use document.location.href to change the page location, place it in the function on a successful ajax run.

batch file Copy files with certain extensions from multiple directories into one directory

Just use the XCOPY command with recursive option

xcopy c:\*.doc k:\mybackup /sy

/s will make it "recursive"

java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/dbname

All of the answers here use the Class.forName("my.vandor.Driver"); line to load the driver.

As an (better) alternative you can use the DriverManager helper class which provides you with a handful of methods to handle your JDBC driver/s.

You might want to

  1. Use DriverManager.registerDriver(driverObject); to register your driver to it's list of drivers

Registers the given driver with the DriverManager. A newly-loaded driver class should call the method registerDriver to make itself known to the DriverManager. If the driver is currently registered, no action is taken

  1. Use DriverManager.deregisterDriver(driverObject); to remove it.

Removes the specified driver from the DriverManager's list of registered drivers.

Example:

Driver driver = new oracle.jdbc.OracleDriver();
DriverManager.registerDriver(driver);
Connection conn = DriverManager.getConnection(url, user, password);
// ... 
// and when you don't need anything else from the driver
DriverManager.deregisterDriver(driver);

or better yet, use a DataSource

How do I register a .NET DLL file in the GAC?

I tried just about everything in the comments and it didn't work. So I did gacutil /i "path to my dll" from Powershell and it worked.

Also remember the trick of pressing Shift when you right-click on a file in Windows Explorer to get the option of Copy path.

How to tell which row number is clicked in a table?

A simple and jQuery free solution:

document.querySelector('#elitable').onclick = function(ev) {
   // ev.target <== td element
   // ev.target.parentElement <== tr
   var index = ev.target.parentElement.rowIndex;
}

Bonus: It works even if rows are added/removed dynamically

Android Facebook style slide

I've had a play with this myself, and the best way I could find was to use a FrameLayout and lay a custom HorizontalScrollView (HSV) on top of the menu. Inside the HSV are your application Views, but there is a transparent View as the first child. This means, when the HSV has zero scroll offset, the menu will show through (and still be clickable surprisingly).

When the app starts up, we scroll the HSV to the offset of the first visible application View, and when we want to show the menu we scroll back to reveal the menu through the transparent View.

The code is here, and the bottom two buttons (called HorzScrollWithListMenu and HorzScrollWithImageMenu) in the Launch activity show the best menus I could come up with:

Android sliding menu demo

Screenshot from emulator (mid-scroll):

Screenshot from emulator (mid-scroll)

Screenshot from device (full-scroll). Note my icon is not as wide as the Facebook menu icon, so the menu view and 'app' view are not aligned.

Screenshot from device (full-scroll)

setup android on eclipse but don't know SDK directory

May be i am too much late here and question is already answered, but this may help those who still cannot find sdk location. Open eclipse, click window tab it will show a drop down menu, click preferences, in preferences window click Android, here u go Sdk location is right in front of u copy the address :)

Illegal access: this web application instance has been stopped already

I suspect that this occurs after an attempt to undeploy your app. Do you ever kill off that thread that you've initialised during the init() process ? I would do this in the corresponding destroy() method.

sqlplus: error while loading shared libraries: libsqlplus.so: cannot open shared object file: No such file or directory

On Oracle's own Linux (Version 7.7, PRETTY_NAME="Oracle Linux Server 7.7" in /etc/os-release), if you installed the 18.3 client libraries with

sudo yum install oracle-instantclient18.3-basic.x86_64
sudo yum install oracle-instantclient18.3-sqlplus.x86_64

then you need to put the following in your .bash_profile:

export ORACLE_HOME=/usr/lib/oracle/18.3/client64
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME/lib:$ORACLE_HOME

in order to be able to invoke the SQLPlus client, which, incidentally, is called sqlplus64 on this platform.

How do I convert an ANSI encoded file to UTF-8 with Notepad++?

Maybe this is not the answer you needed, but I encountered similar problem, so I decided to put it here.

I needed to convert 500 xml files to UTF8 via Notepad++. Why Notepad++? When I used the option "Encode in UTF8" (many other converters use the same logic) it messed up all special characters, so I had to use "Convert to UTF8" explicitly.


Here some simple steps to convert multiple files via Notepad++ without messing up with special characters (for ex. diacritical marks).

  1. Run Notepad++ and then open menu Plugins->Plugin Manager->Show Plugin Manager
  2. Install Python Script. When plugin is installed, restart the application.
  3. Choose menu Plugins->Python Script->New script.
  4. Choose its name, and then past the following code:

convertToUTF8.py

import os
import sys
from Npp import notepad # import it first!

filePathSrc="C:\\Users\\" # Path to the folder with files to convert
for root, dirs, files in os.walk(filePathSrc):
    for fn in files: 
        if fn[-4:] == '.xml': # Specify type of the files
            notepad.open(root + "\\" + fn)      
            notepad.runMenuCommand("Encoding", "Convert to UTF-8")
            # notepad.save()
            # if you try to save/replace the file, an annoying confirmation window would popup.
            notepad.saveAs("{}{}".format(fn[:-4], '_utf8.xml')) 
            notepad.close()

After all, run the script

javascript Unable to get property 'value' of undefined or null reference

you have many HTML and java script mistakes includes: tag, using non UTF-8 encoding for form submission, no need,... You must use document.forms.FORMNAME or document.forms[0] for first appear form in page Corrected:

_x000D_
_x000D_
 function validate_frm_new_user_request()_x000D_
{_x000D_
    alert('test');_x000D_
    var valid = true;_x000D_
_x000D_
    if ( document.forms.frm_new_user_request.u_userid.value == "" )_x000D_
    {_x000D_
        alert ( "Please enter your valid ISID Information." );_x000D_
        document.forms.frm_new_user_request.u_userid.focus();_x000D_
        valid = false;_x000D_
  console.log("FALSE::Empty Value ");_x000D_
    }_x000D_
return valid;_x000D_
}
_x000D_
<html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">_x000D_
<head>_x000D_
    <title></title>_x000D_
    <meta content="text/html;charset=UTF-8" http-equiv="content-type" />_x000D_
_x000D_
_x000D_
</head>_x000D_
<body>_x000D_
<form method="post" action="" name="frm_new_user_request" id="frm_new_user_request" onsubmit="return validate_frm_new_user_request();">_x000D_
<center>_x000D_
<table>_x000D_
_x000D_
        <tr align="left">_x000D_
            <td><Label>ISID<em>*:</Label><input maxlength="15" id="u_userid" name="u_userid" size="20" type="text"/></td>_x000D_
            </tr>_x000D_
_x000D_
<tr>_x000D_
            <td align="center" colspan="4">_x000D_
                <input type="image" src="btn.png" border="0" ALT="Create New Request">_x000D_
_x000D_
                </td>_x000D_
        </tr>_x000D_
    </table>_x000D_
</form>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

PHP find difference between two datetimes

Sorry my previous answer was wrong. If you are trying to take total elapsed time between time and timeout in the format Y-m-d H:i:s format, take diff between timeout and time in using DateTime object and format it as '%y-%m-%d %H:%i:%s'.

How to import a class from default package

I can give you this suggestion, As far as know from my C and C++ Programming experience, Once, when I had the same kinda problem, I solved it by changing the dll written structure in ".C" File by changing the name of the function which implemented the JNI native functionality. for example, If you would like to add your program in the package "com.mypackage", You change the prototype of the JNI implementing ".C" File's function/method to this one:

JNIEXPORT jint JNICALL
Java_com_mypackage_Calculations_Calculate(JNIEnv *env, jobject obj, jint contextId)
{
   //code goes here
}

JNIEXPORT jdouble JNICALL
Java_com_mypackage_Calculations_GetProgress(JNIEnv *env, jobject obj, jint contextId)
{
  //code goes here
}

Since I am new to delphi, I can not guarantee you but will say this finally, (I learned few things after googling about Delphi and JNI): Ask those people (If you are not the one) who provided the Delphi implementation of the native code to change the function names to something like this:

function Java_com_mypackage_Calculations_Calculate(PEnv: PJNIEnv; Obj: JObject; contextId: JInt):JInt; {$IFDEF WIN32} stdcall; {$ENDIF} {$IFDEF LINUX} cdecl; {$ENDIF}
var
//Any variables you might be interested in
begin
  //Some code goes here
end;



function Java_com_mypackage_Calculations_GetProgress(PEnv: PJNIEnv; Obj: JObject; contextId: JInt):JDouble; {$IFDEF WIN32} stdcall; {$ENDIF} {$IFDEF LINUX} cdecl; {$ENDIF}
var
//Any variables you might be interested in
begin
//Some code goes here
end;

But, A final advice: Although you (If you are the delphi programmer) or them will change the prototypes of these functions and recompile the dll file, once the dll file is compiled, you will not be able to change the package name of your "Java" file again & again. Because, this will again require you or them to change the prototypes of the functions in delphi with changed prefixes (e.g. JAVA_yourpackage_with_underscores_for_inner_packages_JavaFileName_MethodName)

I think this solves the problem. Thanks and regards, Harshal Malshe