Programs & Examples On #Parent child

A relationship between entities in which one acts in a major role and the other in a minor role. Also an inheritance relationship paradigm.

How to select <td> of the <table> with javascript?

There are a lot of ways to accomplish this, and this is but one of them.

$("table").find("tbody td").eq(0).children().first()

CSS :: child set to change color on parent hover, but changes also when hovered itself

If you don't care about supporting old browsers, you can use :not() to exclude that element:

.parent:hover span:not(:hover) {
    border: 10px solid red;
}

Demo: http://jsfiddle.net/vz9A9/1/

If you do want to support them, the I guess you'll have to either use JavaScript or override the CSS properties again:

.parent span:hover {
    border: 10px solid green;
}

How to pass data from 2nd activity to 1st activity when pressed back? - android

From your FirstActivity call the SecondActivity using startActivityForResult() method.

For example:

Intent i = new Intent(this, SecondActivity.class);
startActivityForResult(i, 1);

In your SecondActivity set the data which you want to return back to FirstActivity. If you don't want to return back, don't set any.

For example: In secondActivity if you want to send back data:

Intent returnIntent = new Intent();
returnIntent.putExtra("result",result);
setResult(Activity.RESULT_OK,returnIntent);
finish();

If you don't want to return data:

Intent returnIntent = new Intent();
setResult(Activity.RESULT_CANCELED, returnIntent);
finish();

Now in your FirstActivity class write following code for the onActivityResult() method.

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1) {
        if(resultCode == Activity.RESULT_OK){
            String result=data.getStringExtra("result");
        }
        if (resultCode == Activity.RESULT_CANCELED) {
            //Write your code if there's no result
        }
    }
}

Cross browser method to fit a child div to its parent's width

In case you want to use that padding space... then here's something:

http://jsfiddle.net/qD4zd/

All the colors are background colors.

The specified child already has a parent. You must call removeView() on the child's parent first (Android)

My case was different the child view already had a parent view i am adding the child view inside parent view to different parent. example code below

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/lineGap"
>
<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textColor="@color/black1"
    android:layout_gravity="center"
    android:gravity="center"
    />

</LinearLayout>

And i was inflating this view and adding to another LinearLayout, then i removed the LinaarLayout from the above layout and its started working

below code fixed the issue:

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:gravity="center"
   android:textColor="@color/black1" />

How to set opacity in parent div and not affect in child div?

I had the same problem and I fixed by setting transparent png image as background for the parent tag.

This is the 1px x 1px PNG Image that I have created with 60% Opacity of black background !

How do I pass a value from a child back to the parent form?

Many ways to skin the cat here and @Mitch's suggestion is a good way. If you want the client form to have more 'control', you may want to pass the instance of the parent to the child when created and then you can call any public parent method on the child.

get parent's view from a layout

Check my answer here

The use of Layout Inspector tool can be very convenient when you have a complex view or you are using a third party library where you can't add an id to a view

Make absolute positioned div expand parent div height

Feeela is right but you can get a parent div contracting or expanding to a child element if you reverse your div positioning like this:

.parent {
    position: absolute;
    /* position it in the browser using the `left`, `top` and `margin` 
       attributes */
}

.child {
    position: relative;
    height: 100%;
    width: 100%;

    overflow: hidden;
    /* to pad or move it around using `left` and `top` inside the parent */
}

This should work for you.

JavaScript DOM: Find Element Index In Container

Just pass the object reference to the following function and you will get the index

function thisindex(elm) 
{ 
    var the_li = elm; 
    var the_ul = elm.parentNode; 
    var li_list = the_ul.childNodes; 

    var count = 0; // Tracks the index of LI nodes

    // Step through all the child nodes of the UL
    for( var i = 0; i < li_list.length; i++ )
    {
        var node = li_list.item(i);
        if( node )
        {
        // Check to see if the node is a LI
            if( node.nodeName == "LI" )
            {
            // Increment the count of LI nodes
                count++;
            // Check to see if this node is the one passed in
                if( the_li == node )
                {
                    // If so, alert the current count
                    alert(count-1);
                }
            }
        }
    }
}

Maven: Non-resolvable parent POM

Just add <relativePath /> so the parent in pom should look like:

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.4.RELEASE</version>
        <relativePath />
    </parent>

jQuery - selecting elements from inside a element

Why not just use:

$("#foo span")

or

$("#foo > span")

$('span', $('#foo')); works fine on my machine ;)

Example of waitpid() in use?

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>

int main (){
    int pid;
    int status;

    printf("Parent: %d\n", getpid());

    pid = fork();
    if (pid == 0){
        printf("Child %d\n", getpid());
        sleep(2);
        exit(EXIT_SUCCESS);
    }

//Comment from here to...
    //Parent waits process pid (child)
    waitpid(pid, &status, 0);
    //Option is 0 since I check it later

    if (WIFSIGNALED(status)){
        printf("Error\n");
    }
    else if (WEXITSTATUS(status)){
        printf("Exited Normally\n");
    }
//To Here and see the difference
    printf("Parent: %d\n", getpid());

    return 0;
}

Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.Button.Borderless.Colored'

in my case i was using compile sdk 23 and build tools 25.0.0 just changed compile sdk to 25 and done..

Global variables in c#.net

/// <summary>
/// Contains global variables for project.
/// </summary>
public static class GlobalVar
{
/// <summary>
/// Global variable that is constant.
/// </summary>
public const string GlobalString = "Important Text";

/// <summary>
/// Static value protected by access routine.
/// </summary>
static int _globalValue;

/// <summary>
/// Access routine for global variable.
/// </summary>
public static int GlobalValue
{
get
{
    return _globalValue;
}
set
{
    _globalValue = value;
}
}

/// <summary>
/// Global static field.
/// </summary>
public static bool GlobalBoolean;
}

Centering brand logo in Bootstrap Navbar

Try this:

.navbar {
    position: relative;
}
.brand {
    position: absolute;
    left: 50%;
    margin-left: -50px !important;  /* 50% of your logo width */
    display: block;
}

Centering your logo by 50% and minus half of your logo width so that it won't have problem when zooming in and out.

See fiddle

Enter export password to generate a P12 certificate

I know this thread has been idle for a while, but I just wanted to add my two cents to supplement jariq's comment...

Per manual, you don't necessary want to use -password option.

Let's say mykey.key has a password and your want to protect iphone-dev.p12 with another password, this is what you'd use:

pkcs12 -export -inkey mykey.key -in developer_identity.pem -out iphone_dev.p12 -passin pass:password_for_mykey -passout pass:password_for_iphone_dev

Have fun scripting!!

Styling input radio with css

Here is simple example of how you can do this.

Just replace the image file and you are done.

HTML Code

<input type="radio" id="r1" name="rr" />
<label for="r1"><span></span>Radio Button 1</label>
<p>
<input type="radio" id="r2" name="rr" />
<label for="r2"><span></span>Radio Button 2</label>

CSS

input[type="radio"] {
    display:none;
}

input[type="radio"] + label {
    color:#f2f2f2;
    font-family:Arial, sans-serif;
    font-size:14px;
}

input[type="radio"] + label span {
    display:inline-block;
    width:19px;
    height:19px;
    margin:-1px 4px 0 0;
    vertical-align:middle;
    background:url(check_radio_sheet.png) -38px top no-repeat;
    cursor:pointer;
}

input[type="radio"]:checked + label span {
    background:url(check_radio_sheet.png) -57px top no-repeat;
}

Working DEMO

Angular 4.3 - HttpClient set params

Using this you can avoid the loop.

// obj is the params object with key-value pair. 
// This is how you convert that to HttpParams and pass this to GET API. 

const params = Object.getOwnPropertyNames(obj)
               .reduce((p, key) => p.set(key, obj[key]), new HttpParams());

Furthermore, I suggest making toHttpParams function in your commonly used service. So you can call the function to convert the object to the HttpParams.

/**
 * Convert Object to HttpParams
 * @param {Object} obj
 * @returns {HttpParams}
 */
toHttpParams(obj: Object): HttpParams {
    return Object.getOwnPropertyNames(obj)
        .reduce((p, key) => p.set(key, obj[key]), new HttpParams());
}

Update:

Since 5.0.0-beta.6 (2017-09-03) they added new feature (accept object map for HttpClient headers & params)

Going forward the object can be passed directly instead of HttpParams.

This is the other reason if you have used one common function like toHttpParams mentioned above, you can easily remove it or do changes if required.

How can I remove item from querystring in asp.net using c#?

string queryString = "Default.aspx?Agent=10&Language=2"; //Request.QueryString.ToString();
string parameterToRemove="Language";   //parameter which we want to remove
string regex=string.Format("(&{0}=[^&\s]+|{0}=[^&\s]+&?)",parameterToRemove);
string finalQS = Regex.Replace(queryString, regex, "");

https://regexr.com/3i9vj

How to find a value in an excel column by vba code Cells.Find

Dim strFirstAddress As String
Dim searchlast As Range
Dim search As Range

Set search = ActiveSheet.Range("A1:A100")
Set searchlast = search.Cells(search.Cells.Count)

Set rngFindValue = ActiveSheet.Range("A1:A100").Find(Text, searchlast, xlValues)
If Not rngFindValue Is Nothing Then
  strFirstAddress = rngFindValue.Address
  Do
    Set rngFindValue = search.FindNext(rngFindValue)
  Loop Until rngFindValue.Address = strFirstAddress

What's the quickest way to multiply multiple cells by another number?

Select Product from formula bar in your answer cell.

Select cells you want to multiply.

C#: Dynamic runtime cast

I realize this has been answered, but I used a different approach and thought it might be worth sharing. Also, I feel like my approach might produce unwanted overhead. However, I'm not able to observer or calculate anything happening that is that bad under the loads we observe. I was looking for any useful feedback on this approach.

The problem with working with dynamics is that you can't attach any functions to the dynamic object directly. You have to use something that can figure out the assignments that you don't want to figure out every time.

When planning this simple solution, I looked at what the valid intermediaries are when attempting to retype similar objects. I found that a binary array, string (xml, json) or hard coding a conversion (IConvertable) were the usual approaches. I don't want to get into binary conversions due to a code maintainability factor and laziness.

My theory was that Newtonsoft could do this by using a string intermediary.

As a downside, I am fairly certain that when converting the string to an object, that it would use reflection by searching the current assembly for an object with matching properties, create the type, then instantiate the properties, which would require more reflection. If true, all of this can be considered avoidable overhead.

C#:

//This lives in a helper class
public static ConvertDynamic<T>(dynamic data)
{
     return Newtonsoft.Json.JsonConvert.DeserializeObject<T>(Newtonsoft.Json.JsonConvert.SerializeObject(data));
}

//Same helper, but in an extension class (public static class),
//but could be in a base class also.
public static ToModelList<T>(this List<dynamic> list)
{
    List<T> retList = new List<T>();
    foreach(dynamic d in list)
    {
        retList.Add(ConvertDynamic<T>(d));
    }
}

With that said, this fits another utility I've put together that lets me make any object into a dynamic. I know I had to use reflection to do that correctly:

public static dynamic ToDynamic(this object value)
{
    IDictionary<string, object> expando = new ExpandoObject();

    foreach (PropertyDescriptor property in TypeDescriptor.GetProperties(value.GetType()))
        expando.Add(property.Name, property.GetValue(value));

    return expando as ExpandoObject;
}

I had to offer that function. An arbitrary object assigned to a dynamic typed variable cannot be converted to an IDictionary, and will break the ConvertDynamic function. For this function chain to be used it has to be provided a dynamic of System.Dynamic.ExpandoObject, or IDictionary<string, object>.

Apache 2.4.3 (with XAMPP 1.8.1) not starting in windows 8

So here is the solution for this:

I check port 80 used by Skype, after that I changes port to 81 and also along with that somewhere i read this error may be because of SSL Port then I changed SSL port to 444. However this got resolved easily.

One most important thing to notice here, all the port changes should be done inside config files, for http port change: httpd.conf for SSL httpd-ssl.conf. Otherwise changes will not replicate to Apache, Sometime PC reboot is also required.

Edit: Make Apache use port 80 and make Skype communicate on other Port

For those who are struggling with Skype, want to change its port and to make Apache to use port 80.

No need to Re-Install, Here is simply how to change Skype Port

Goto: Tools > Options > Advanced > Connection

There you need to uncheck Use port 80 and 443 as alternative for incoming connections.

That's it, here is screen shot of it.

Changing Skype Port

Using the HTML5 "required" attribute for a group of checkboxes?

we can do this easily with html5 also, just need to add some jquery code

Demo

HTML

<form>
 <div class="form-group options">
   <input type="checkbox" name="type[]" value="A" required /> A
   <input type="checkbox" name="type[]" value="B" required /> B
   <input type="checkbox" name="type[]" value="C" required /> C
   <input type="submit">
 </div>
</form>

Jquery

$(function(){
    var requiredCheckboxes = $('.options :checkbox[required]');
    requiredCheckboxes.change(function(){
        if(requiredCheckboxes.is(':checked')) {
            requiredCheckboxes.removeAttr('required');
        } else {
            requiredCheckboxes.attr('required', 'required');
        }
    });
});

Exploitable PHP functions

I guess you won't be able to really find all possible exploits by parsing your source files.

  • also if there are really great lists provided in here, you can miss a function which can be exploitet

  • there still could be "hidden" evil code like this

$myEvilRegex = base64_decode('Ly4qL2U=');

preg_replace($myEvilRegex, $_POST['code']);

  • you could now say, i simply extend my script to also match this

  • but then you will have that mayn "possibly evil code" which additionally is out of it's context

  • so to be (pseudo-)secure, you should really write good code and read all existing code yourself

Go / golang time.Now().UnixNano() convert to milliseconds?

I think it's better to round the time to milliseconds before the division.

func makeTimestamp() int64 {
    return time.Now().Round(time.Millisecond).UnixNano() / (int64(time.Millisecond)/int64(time.Nanosecond))
}

Here is an example program:

package main

import (
        "fmt"
        "time"
)

func main() {
        fmt.Println(unixMilli(time.Unix(0, 123400000)))
        fmt.Println(unixMilli(time.Unix(0, 123500000)))
        m := makeTimestampMilli()
        fmt.Println(m)
        fmt.Println(time.Unix(m/1e3, (m%1e3)*int64(time.Millisecond)/int64(time.Nanosecond)))
}

func unixMilli(t time.Time) int64 {
        return t.Round(time.Millisecond).UnixNano() / (int64(time.Millisecond) / int64(time.Nanosecond))
}

func makeTimestampMilli() int64 {
        return unixMilli(time.Now())
}

The above program printed the result below on my machine:

123
124
1472313624305
2016-08-28 01:00:24.305 +0900 JST

How to get value of checked item from CheckedListBox?

To get the all selected Items in a CheckedListBox try this:

In this case ths value is a String but it's run with other type of Object:

for (int i = 0; i < myCheckedListBox.Items.Count; i++)
{
    if (myCheckedListBox.GetItemChecked(i) == true)
    {

        MessageBox.Show("This is the value of ceckhed Item " + myCheckedListBox.Items[i].ToString());

    }

}

MVC4 DataType.Date EditorFor won't display date value in Chrome, fine in Internet Explorer

In MVC5.2, add Date.cshtml to folder ~/Views/Shared/EditorTemplates:

@model DateTime?
@{
    IDictionary<string, object> htmlAttributes;
    object objAttributes;
    if (ViewData.TryGetValue("htmlAttributes", out objAttributes))
    {
        htmlAttributes = objAttributes as IDictionary<string, object> ?? HtmlHelper.AnonymousObjectToHtmlAttributes(objAttributes);
    }
    else
    {
        htmlAttributes = new RouteValueDictionary();
    }
    htmlAttributes.Add("type", "date");
    String format = (Request.UserAgent != null && Request.UserAgent.Contains("Chrome")) ? "{0:yyyy-MM-dd}" : "{0:d}";
    @Html.TextBox("", Model, format, htmlAttributes)
}

PHP error: Notice: Undefined index:

You're attempting to access indicies within an array which are not set. This raises a notice.

Mostly likely you're noticing it now because your code has moved to a server where php.ini has error_reporting set to include E_NOTICE. Either suppress notices by setting error_reporting to E_ALL & ~E_NOTICE (not recommended), or verify that the index exists before you attempt to access it:

$month = array_key_exists('month', $_POST) ? $_POST['month'] : null;

SQL Server AS statement aliased column within WHERE statement

I am not sure why you cannot use "lat" but, if you must you can rename the columns in a derived table.

select a.latitude from (SELECT lat AS latitude FROM poi_table) a where latitude < 500

Passing string parameter in JavaScript function

Change your code to

document.write("<td width='74'><button id='button' type='button' onclick='myfunction(\""+ name + "\")'>click</button></td>")

Javascript form validation with password confirming

Just add onsubmit event handler for your form:

<form  action="insert.php" onsubmit="return myFunction()" method="post">

Remove onclick from button and make it input with type submit

<input type="submit" value="Submit">

And add boolean return statements to your function:

function myFunction() {
    var pass1 = document.getElementById("pass1").value;
    var pass2 = document.getElementById("pass2").value;
    var ok = true;
    if (pass1 != pass2) {
        //alert("Passwords Do not match");
        document.getElementById("pass1").style.borderColor = "#E34234";
        document.getElementById("pass2").style.borderColor = "#E34234";
        return false;
    }
    else {
        alert("Passwords Match!!!");
    }
    return ok;
}

How to split comma separated string using JavaScript?

var array = string.split(',')

and good morning, too, since I have to type 30 chars ...

How to get first N elements of a list in C#?

Like pagination you can use below formule for taking slice of list or elements:

var slice = myList.Skip((pageNumber - 1) * pageSize)
                  .Take(pageSize);

Example 1: first five items

var pageNumber = 1;
var pageSize = 5;

Example 2: second five items

var pageNumber = 2;
var pageSize = 5;

Example 3: third five items

var pageNumber = 3;
var pageSize = 5;

If notice to formule parameters pageSize = 5 and pageNumber is changing, if you want to change number of items in slicing you change pageSize.

How do I quickly rename a MySQL database (change schema name)?

Here is a one-line Bash snippet to move all tables from one schema to another:

history -d $((HISTCMD-1)) && mysql -udb_user -p'db_password' -Dold_schema -ABNnqre'SHOW TABLES;' | sed -e's/.*/RENAME TABLE old_schema.`&` TO new_schema.`&`;/' | mysql -udb_user -p'db_password' -Dnew_schema

The history command at the start simply ensures that the MySQL commands containing passwords aren't saved to the shell history.

Make sure that db_user has read/write/drop permissions on the old schema, and read/write/create permissions on the new schema.

How to add a new project to Github using VS Code

today is 2020-12-25, my VSC is 1.52.1, tried all above not very successful. Here is complete steps I did to add my existing local project to GitHub using VSC (Note: Do not create a corresponding repository at GitHub):

  1. Install the GibHub extension to VSC.
  2. Close and re-open VSC.
  3. Sign in to GibHub if prompted.
  4. Open my own local folder, up to this moment, it's not pushed to GibHub yet.
  5. Ctrl + Shift + P, click on Publish to GitHub.

enter image description here

  1. VSC and GitHub will automatically provide you a choice of adding it as private or public, and make up a name for your to-be new repository in this format: <your username>/<your new repository name>. For example, my username is "myname" and my local folder is named "HelloWorld". So, it will be myname/HelloWorld in the type-in box.
  2. update or accept this name, click on the private or public choice will Create a new repository at GitHub and Publish your folder to it.

enter image description here

Why do we use web.xml?

The web.xml file is the deployment descriptor for a Servlet-based Java web application (which most Java web apps are). Among other things, it declares which Servlets exist and which URLs they handle.

The part you cite defines a Servlet Filter. Servlet filters can do all kinds of preprocessing on requests. Your specific example is a filter had the Wicket framework uses as its entry point for all requests because filters are in some way more powerful than Servlets.

Add data to JSONObject

The accepted answer by Francisco Spaeth works and is easy to follow. However, I think that method of building JSON sucks! This was really driven home for me as I converted some Python to Java where I could use dictionaries and nested lists, etc. to build JSON with ridiculously greater ease.

What I really don't like is having to instantiate separate objects (and generally even name them) to build up these nestings. If you have a lot of objects or data to deal with, or your use is more abstract, that is a real pain!

I tried getting around some of that by attempting to clear and reuse temp json objects and lists, but that didn't work for me because all the puts and gets, etc. in these Java objects work by reference not value. So, I'd end up with JSON objects containing a bunch of screwy data after still having some ugly (albeit differently styled) code.

So, here's what I came up with to clean this up. It could use further development, but this should help serve as a base for those of you looking for more reasonable JSON building code:

import java.util.AbstractMap.SimpleEntry;
import java.util.ArrayList;
import java.util.List;
import org.json.simple.JSONObject;

//  create and initialize an object 
public static JSONObject buildObject( final SimpleEntry... entries ) { 
    JSONObject object = new JSONObject();
    for( SimpleEntry e : entries ) object.put( e.getKey(), e.getValue() );
    return object;
}

//  nest a list of objects inside another                          
public static void putObjects( final JSONObject parentObject, final String key,
                               final JSONObject... objects ) { 
    List objectList = new ArrayList<JSONObject>();
    for( JSONObject o : objects ) objectList.add( o );
    parentObject.put( key, objectList );
}   

Implementation example:

JSONObject jsonRequest = new JSONObject();
putObjects( jsonRequest, "parent1Key",
    buildObject( 
        new SimpleEntry( "child1Key1", "someValue" )
      , new SimpleEntry( "child1Key2", "someValue" ) 
    )
  , buildObject( 
        new SimpleEntry( "child2Key1", "someValue" )
      , new SimpleEntry( "child2Key2", "someValue" ) 
    )
);      

how to use DEXtoJar

The below url is doing same as above answers. Instead of downloading some jar files and doing much activities, you can try to decompile by:

http://apk-deguard.com/

Rails: How to reference images in CSS within Rails 4

This should get you there every single time.

background-image: url(<%= asset_data_uri 'transparent_2x2.png'%>);

Convert String to Type in C#

Try:

Type type = Type.GetType(inputString); //target type
object o = Activator.CreateInstance(type); // an instance of target type
YourType your = (YourType)o;

Jon Skeet is right as usually :)

Update: You can specify assembly containing target type in various ways, as Jon mentioned, or:

YourType your = (YourType)Activator.CreateInstance("AssemblyName", "NameSpace.MyClass");

NSDate get year/month/day

In Swift 2.0:

    let date = NSDate()
    let calendar = NSCalendar(identifier: NSCalendarIdentifierGregorian)!
    let components = calendar.components([.Month, .Day], fromDate: date)

    let (month, day) = (components.month, components.day)

Renaming Column Names in Pandas Groupby function

The current (as of version 0.20) method for changing column names after a groupby operation is to chain the rename method. See this deprecation note in the documentation for more detail.

Deprecated Answer as of pandas version 0.20

This is the first result in google and although the top answer works it does not really answer the question. There is a better answer here and a long discussion on github about the full functionality of passing dictionaries to the agg method.

These answers unfortunately do not exist in the documentation but the general format for grouping, aggregating and then renaming columns uses a dictionary of dictionaries. The keys to the outer dictionary are column names that are to be aggregated. The inner dictionaries have keys that the new column names with values as the aggregating function.

Before we get there, let's create a four column DataFrame.

df = pd.DataFrame({'A' : list('wwwwxxxx'), 
                   'B':list('yyzzyyzz'), 
                   'C':np.random.rand(8), 
                   'D':np.random.rand(8)})

   A  B         C         D
0  w  y  0.643784  0.828486
1  w  y  0.308682  0.994078
2  w  z  0.518000  0.725663
3  w  z  0.486656  0.259547
4  x  y  0.089913  0.238452
5  x  y  0.688177  0.753107
6  x  z  0.955035  0.462677
7  x  z  0.892066  0.368850

Let's say we want to group by columns A, B and aggregate column C with mean and median and aggregate column D with max. The following code would do this.

df.groupby(['A', 'B']).agg({'C':['mean', 'median'], 'D':'max'})

            D         C          
          max      mean    median
A B                              
w y  0.994078  0.476233  0.476233
  z  0.725663  0.502328  0.502328
x y  0.753107  0.389045  0.389045
  z  0.462677  0.923551  0.923551

This returns a DataFrame with a hierarchical index. The original question asked about renaming the columns in the same step. This is possible using a dictionary of dictionaries:

df.groupby(['A', 'B']).agg({'C':{'C_mean': 'mean', 'C_median': 'median'}, 
                            'D':{'D_max': 'max'}})

            D         C          
        D_max    C_mean  C_median
A B                              
w y  0.994078  0.476233  0.476233
  z  0.725663  0.502328  0.502328
x y  0.753107  0.389045  0.389045
  z  0.462677  0.923551  0.923551

This renames the columns all in one go but still leaves the hierarchical index which the top level can be dropped with df.columns = df.columns.droplevel(0).

Calling JMX MBean method from a shell script

I've developed jmxfuse which exposes JMX Mbeans as a Linux FUSE filesystem with similar functionality as the /proc fs. It relies on Jolokia as the bridge to JMX. Attributes and operations are exposed for reading and writing.

http://code.google.com/p/jmxfuse/

For example, to read an attribute:

me@oddjob:jmx$ cd log4j/root/attributes
me@oddjob:jmx$ cat priority

to write an attribute:

me@oddjob:jmx$ echo "WARN" > priority

to invoke an operation:

me@oddjob:jmx$ cd Catalina/none/none/WebModule/localhost/helloworld/operations/addParameter
me@oddjob:jmx$ echo "myParam myValue" > invoke

How to create a drop shadow only on one side of an element?

UPDATE 4

Same like update 3 but with modern css (=less rules) so that no special positioning on the pseudo element is required.

_x000D_
_x000D_
#box {_x000D_
    background-color: #3D6AA2;_x000D_
    width: 160px;_x000D_
    height: 90px;_x000D_
    position: absolute;_x000D_
    top: calc(10% - 10px);_x000D_
    left: calc(50% - 80px);_x000D_
}_x000D_
_x000D_
.box-shadow:after {_x000D_
    content:"";_x000D_
    position:absolute;_x000D_
    width:100%;_x000D_
    bottom:1px;_x000D_
    z-index:-1;_x000D_
    transform:scale(.9);_x000D_
    box-shadow: 0px 0px 8px 2px #000000;_x000D_
}
_x000D_
<div id="box" class="box-shadow"></div>
_x000D_
_x000D_
_x000D_

UPDATE 3

All my previous answers have been using extra markup to get create this effect, which is not necessarily needed. I think this a much cleaner solution... the only trick is playing around with the values to get the right positioning of the shadow as well as the right strength/opacity of the shadow. Here's a new fiddle, using pseudo-elements:

http://jsfiddle.net/UnsungHero97/ARRRZ/2/

HTML

<div id="box" class="box-shadow"></div>

CSS

#box {
    background-color: #3D6AA2;
    width: 160px;
    height: 90px;
    margin-top: -45px;
    margin-left: -80px;
    position: absolute;
    top: 50%;
    left: 50%;
}

.box-shadow:after {
    content: "";
    width: 150px;
    height: 1px;
    margin-top: 88px;
    margin-left: -75px;
    display: block;
    position: absolute;
    left: 50%;
    z-index: -1;
    -webkit-box-shadow: 0px 0px 8px 2px #000000;
       -moz-box-shadow: 0px 0px 8px 2px #000000;
            box-shadow: 0px 0px 8px 2px #000000;
}

UPDATE 2

Apparently, you can do this with just an extra parameter to the box-shadow CSS as everyone else just pointed out. Here's the demo:

http://jsfiddle.net/K88H9/821/

CSS

-webkit-box-shadow: 0 4px 4px -2px #000000;
   -moz-box-shadow: 0 4px 4px -2px #000000;
        box-shadow: 0 4px 4px -2px #000000;

This would be a better solution. The extra parameter that is added is described as:

The fourth length is a spread distance. Positive values cause the shadow shape to expand in all directions by the specified radius. Negative values cause the shadow shape to contract.

UPDATE

Check out the demo at jsFiddle: http://jsfiddle.net/K88H9/4/

What I did was create a "shadow element" that would hide behind the actual element that you would want to have a shadow. I made the width of the "shadow element" to be exactly less wide than the actual element by 2 times the shadow you specify; then I aligned it properly.

HTML

<div id="wrapper">
    <div id="element"></div>
    <div id="shadow"></div>
</div>

CSS

#wrapper {
    width: 84px;
    position: relative;
}
#element {
    background-color: #3D668F;
    height: 54px;
    width: 100%;
    position: relative;
    z-index: 10;
}
#shadow {
    background-color: #3D668F;
    height: 8px;
    width: 80px;
    margin-left: -40px;
    position: absolute;
    bottom: 0px;
    left: 50%;
    z-index: 5;
    -webkit-box-shadow: 0px 2px 4px #000000;
       -moz-box-shadow: 0px 2px 4px #000000;
            box-shadow: 0px 2px 4px #000000;
}

Original Answer

Yes, you can do this with the same syntax you have provided. The first value controls the horizontal positioning and the second value controls the vertical positioning. So just set the first value to 0px and the second to whatever offset you'd like as follows:

-webkit-box-shadow: 0px 5px #000000;
   -moz-box-shadow: 0px 5px #000000;
        box-shadow: 0px 5px #000000;

For more info on box shadows, check out these:

I hope this helps.

Cordova : Requirements check failed for JDK 1.8 or greater

As per official Cordova documentation it supports only JDK 1.8 not greater till the date (April 2018). Or there might be problem with version detection script within cordova.

Cordova: Installing the requirements

Draw a line in a div

Answered this just to emphasize @rblarsen comment on question :

You don't need the style tags in the CSS-file

If you remove the style tag from your css file it will work.

find all unchecked checkbox in jquery

Also it can be achieved with pure js in such a way:

var matches = document.querySelectorAll('input[type="checkbox"]:not(:checked)');

Python extending with - using super() Python 3 vs Python 2

Just to have a simple and complete example for Python 3, which most people seem to be using now.

class MySuper(object):
    def __init__(self,a):
        self.a = a

class MySub(MySuper):
    def __init__(self,a,b):
        self.b = b
        super().__init__(a)

my_sub = MySub(42,'chickenman')
print(my_sub.a)
print(my_sub.b)

gives

42
chickenman

Store a cmdlet's result value in a variable in Powershell

Use the -ExpandProperty flag of Select-Object

$var=Get-WSManInstance -enumerate wmicimv2/win32_process | select -expand Priority

Update to answer the other question:

Note that you can as well just access the property:

$var=(Get-WSManInstance -enumerate wmicimv2/win32_process).Priority

So to get multiple of these into variables:

$var=Get-WSManInstance -enumerate wmicimv2/win32_process
   $prio = $var.Priority
   $pid = $var.ProcessID

How to return only the Date from a SQL Server DateTime datatype

DATEADD and DATEDIFF are better than CONVERTing to varchar. Both queries have the same execution plan, but execution plans are primarly about data access strategies and do not always reveal implicit costs involved in the CPU time taken to perform all the pieces. If both queries are run against a table with millions of rows, the CPU time using DateDiff can be close to 1/3rd of the Convert CPU time!

To see execution plans for queries:

set showplan_text on
GO 

Both DATEADD and DATEDIFF will execute a CONVERT_IMPLICIT.

Although the CONVERT solution is simpler and easier to read for some, it is slower. There is no need to cast back to datetime (this is implicitly done by the server). There is also no real need in the DateDiff method for DateAdd afterward as the integer result will also be implicitly converted back to datetime.


SELECT CONVERT(varchar, MyDate, 101) FROM DatesTable

  |--Compute Scalar(DEFINE:([Expr1004]=CONVERT(varchar(30),[TEST].[dbo].[DatesTable].[MyDate],101)))
       |--Table Scan(OBJECT:([TEST].[dbo].[DatesTable]))

SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, MyDate)) FROM DatesTable

  |--Compute Scalar(DEFINE:([Expr1004]=dateadd(day,(0),CONVERT_IMPLICIT(datetime,datediff(day,'1900-01-01 00:00:00.000',CONVERT_IMPLICIT(datetime,[TEST].[dbo].[DatesTable].[MyDate],0)),0))))
       |--Table Scan(OBJECT:([TEST].[dbo].[DatesTable]))

Using FLOOR() as @digi suggested has performance closer to DateDiff, but is not recommended as casting the datetime data type to float and back does not always yield the original value.

Remember guys: Don't believe anyone. Look at the performance statistics, and test it yourself!

Be careful when you're testing your results. Selecting many rows to the client will hide the performance difference becauses it takes longer to send the rows over the network than it does to perform the calculations. So make sure that the work for all the rows is done by the server but there is no rowset sent to the client.

There seems to be confusion for some people about when cache optimization affects queries. Running two queries in the same batch or in separate batches has no effect on caching. So you can either expire the cache manually or simply run the queries back and forth multiple times. Any optimization for query #2 would also affect any subsequent queries, so throw out execution #1 if you like.

Here is full test script and performance results that prove DateDiff is substantially faster than converting to varchar.

java.lang.OutOfMemoryError: Java heap space in Maven

The chances are that the problem is in one of the unit tests that you've asked Maven to run.

As such, fiddling with the heap size is the wrong approach. Instead, you should be looking at the unit test that has caused the OOME, and trying to figure out if it is the fault of the unit test or the code that it is testing.

Start by looking at the stack trace. If there isn't one, run mvn ... test again with the -e option.

Ignore files that have already been committed to a Git repository

If you are trying to ignore changes to a file that's already tracked in the repository (e.g. a dev.properties file that you would need to change for your local environment but you would never want to check in these changes) than what you want to do is:

git update-index --assume-unchanged <file>

If you wanna start tracking changes again

git update-index --no-assume-unchanged <file>

See git-update-index(1) Manual Page.

Also have a look at the skip-worktree and no-skip-worktree options for update-index if you need this to persist past a git-reset (via)


Update: Since people have been asking, here's a convenient (and updated since commented on below) alias for seeing which files are currently "ignored" (--assume-unchanged) in your local workspace

$ git config --global alias.ignored = !git ls-files -v | grep "^[[:lower:]]"

mongodb group values by multiple fields

Using aggregate function like below :

[
{$group: {_id : {book : '$book',address:'$addr'}, total:{$sum :1}}},
{$project : {book : '$_id.book', address : '$_id.address', total : '$total', _id : 0}}
]

it will give you result like following :

        {
            "total" : 1,
            "book" : "book33",
            "address" : "address90"
        }, 
        {
            "total" : 1,
            "book" : "book5",
            "address" : "address1"
        }, 
        {
            "total" : 1,
            "book" : "book99",
            "address" : "address9"
        }, 
        {
            "total" : 1,
            "book" : "book1",
            "address" : "address5"
        }, 
        {
            "total" : 1,
            "book" : "book5",
            "address" : "address2"
        }, 
        {
            "total" : 1,
            "book" : "book3",
            "address" : "address4"
        }, 
        {
            "total" : 1,
            "book" : "book11",
            "address" : "address77"
        }, 
        {
            "total" : 1,
            "book" : "book9",
            "address" : "address3"
        }, 
        {
            "total" : 1,
            "book" : "book1",
            "address" : "address15"
        }, 
        {
            "total" : 2,
            "book" : "book1",
            "address" : "address2"
        }, 
        {
            "total" : 3,
            "book" : "book1",
            "address" : "address1"
        }

I didn't quite get your expected result format, so feel free to modify this to one you need.

Does MySQL ignore null values on unique constraints?

I am unsure if the author originally was just asking whether or not this allows duplicate values or if there was an implied question here asking, "How to allow duplicate NULL values while using UNIQUE?" Or "How to only allow one UNIQUE NULL value?"

The question has already been answered, yes you can have duplicate NULL values while using the UNIQUE index.

Since I stumbled upon this answer while searching for "how to allow one UNIQUE NULL value." For anyone else who may stumble upon this question while doing the same, the rest of my answer is for you...

In MySQL you can not have one UNIQUE NULL value, however you can have one UNIQUE empty value by inserting with the value of an empty string.

Warning: Numeric and types other than string may default to 0 or another default value.

How to set the min and max height or width of a Frame?

There is no single magic function to force a frame to a minimum or fixed size. However, you can certainly force the size of a frame by giving the frame a width and height. You then have to do potentially two more things: when you put this window in a container you need to make sure the geometry manager doesn't shrink or expand the window. Two, if the frame is a container for other widget, turn grid or pack propagation off so that the frame doesn't shrink or expand to fit its own contents.

Note, however, that this won't prevent you from resizing a window to be smaller than an internal frame. In that case the frame will just be clipped.

import Tkinter as tk

root = tk.Tk()
frame1 = tk.Frame(root, width=100, height=100, background="bisque")
frame2 = tk.Frame(root, width=50, height = 50, background="#b22222")

frame1.pack(fill=None, expand=False)
frame2.place(relx=.5, rely=.5, anchor="c")

root.mainloop()

How to handle notification when app in background in Firebase

According to OAUTH 2.0:

There will be Auth problem for this case beacuse FCM now using OAUTH 2

So I read firebase documentation and according to documentation new way to post data message is;

POST: https://fcm.googleapis.com/v1/projects/YOUR_FIREBASEDB_ID/messages:send

Headers

Key: Content-Type, Value: application/json

Auth

Bearer YOUR_TOKEN 

Example Body

{
   "message":{
    "topic" : "xxx",
    "data" : {
         "body" : "This is a Firebase Cloud Messaging Topic Message!",
         "title" : "FCM Message"
          }
      }
 }

In the url there is Database Id which you can find it on your firebase console. (Go project setttings)

And now lets take our token (It will valid only 1 hr):

First in the Firebase console, open Settings > Service Accounts. Click Generate New Private Key, securely store the JSON file containing the key. I was need this JSON file to authorize server requests manually. I downloaded it.

Then I create a node.js project and used this function to get my token;

var PROJECT_ID = 'YOUR_PROJECT_ID';
var HOST = 'fcm.googleapis.com';
var PATH = '/v1/projects/' + PROJECT_ID + '/messages:send';
var MESSAGING_SCOPE = 'https://www.googleapis.com/auth/firebase.messaging';
var SCOPES = [MESSAGING_SCOPE];

  router.get('/', function(req, res, next) {
      res.render('index', { title: 'Express' });
      getAccessToken().then(function(accessToken) {
        console.log("TOKEN: "+accessToken)
      })

    });

function getAccessToken() {
return new Promise(function(resolve, reject) {
    var key = require('./YOUR_DOWNLOADED_JSON_FILE.json');
    var jwtClient = new google.auth.JWT(
        key.client_email,
        null,
        key.private_key,
        SCOPES,
        null
    );
    jwtClient.authorize(function(err, tokens) {
        if (err) {
            reject(err);
            return;
        }
        resolve(tokens.access_token);
    });
});
}

Now I can use this token in my post request. Then I post my data message, and it is now handled by my apps onMessageReceived function.

what does "error : a nonstatic member reference must be relative to a specific object" mean?

CPMSifDlg::EncodeAndSend() method is declared as non-static and thus it must be called using an object of CPMSifDlg. e.g.

CPMSifDlg obj;
return obj.EncodeAndSend(firstName, lastName, roomNumber, userId, userFirstName, userLastName);

If EncodeAndSend doesn't use/relate any specifics of an object (i.e. this) but general for the class CPMSifDlg then declare it as static:

class CPMSifDlg {
...
  static int EncodeAndSend(...);
  ^^^^^^
};

Generate random int value from 3 to 6

In general:

select rand()*(@upper-@lower)+@lower;

For your question:

select rand()*(6-3)+3;

<=>

select rand()*3+3;

What is the best or most commonly used JMX Console / Client

jminix is an embedded web based JMX console. Not sure if it's maintained any longer, but still.

How to check if $_GET is empty?

if (!$_GET) echo "empty";

why do you need such a checking?

lol
you guys too direct-minded.
don't take as offense but sometimes not-minded at all
$_GET is very special variable, not like others.
it is supposed to be always set. no need to treat it as other variables. when $_GET is not set and it's expected - it is emergency case and that's what "Undefined variable" notice invented for

Convert varchar2 to Date ('MM/DD/YYYY') in PL/SQL

Easiest way is probably to convert from a VARCHAR to a DATE; then format it back to a VARCHAR again in the format you want;

SELECT TO_CHAR(TO_DATE(DOJ,'MM/DD/YYYY'), 'MM/DD/YYYY') FROM EmpTable;

An SQLfiddle to test with.

Regex for quoted string with escaping quotes

As provided by ePharaoh, the answer is

/"([^"\\]*(\\.[^"\\]*)*)"/

To have the above apply to either single quoted or double quoted strings, use

/"([^"\\]*(\\.[^"\\]*)*)"|\'([^\'\\]*(\\.[^\'\\]*)*)\'/

sudo: docker-compose: command not found

If you have tried installing via the official docker-compose page, where you need to download the binary using curl:

curl -L https://github.com/docker/compose/releases/download/1.8.0/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose

Then do not forget to add executable flag to the binary:

chmod +x /usr/local/bin/docker-compose

If docker-compose is installed using python-pip

sudo apt-get -y install python-pip
sudo pip install docker-compose

try using pip show --files docker-compose to see where it is installed.

If docker-compose is installed in user path, then try:

sudo "PATH=$PATH" docker-compose

As I see from your updated post, docker-compose is installed in user path /home/user/.local/bin and if this path is not in your local path $PATH, then try:

sudo "PATH=$PATH:/home/user/.local/bin" docker-compose

How can I enable auto complete support in Notepad++?

Go to

Settings -> Preferences -> Backup/Autocompletion

  • Check Enable auto-completion on each input. By default the radio button for Function completion gets checked, that will complete related function name as you type. But when you are editing something other than code, you can check for Word completion.

  • Check Function parameters hint on input, if you find it difficult to remember function parameters and their ordering.

python - find index position in list based of partial string

spell_list = ["Tuesday", "Wednesday", "February", "November", "Annual", "Calendar", "Solstice"]

index=spell_list.index("Annual")
print(index)

Difference between a Structure and a Union

You have it, that's all. But so, basically, what's the point of unions?

You can put in the same location content of different types. You have to know the type of what you have stored in the union (so often you put it in a struct with a type tag...).

Why is this important? Not really for space gains. Yes, you can gain some bits or do some padding, but that's not the main point anymore.

It's for type safety, it enables you to do some kind of 'dynamic typing': the compiler knows that your content may have different meanings and the precise meaning of how your interpret it is up to you at run-time. If you have a pointer that can point to different types, you MUST use a union, otherwise you code may be incorrect due to aliasing problems (the compiler says to itself "oh, only this pointer can point to this type, so I can optimize out those accesses...", and bad things can happen).

How to skip the first n rows in sql query

Do you want something like in LINQ skip 5 and take 10?

SELECT TOP(10) * FROM MY_TABLE  
WHERE ID not in (SELECT TOP(5) ID From My_TABLE);

This approach will work in any SQL version.

How to move certain commits to be based on another branch in git?

This is a classic case of rebase --onto:

 # let's go to current master (X, where quickfix2 should begin)
 git checkout master

 # replay every commit *after* quickfix1 up to quickfix2 HEAD.
 git rebase --onto master quickfix1 quickfix2 

So you should go from

o-o-X (master HEAD)
     \ 
      q1a--q1b (quickfix1 HEAD)
              \
               q2a--q2b (quickfix2 HEAD)

to:

      q2a'--q2b' (new quickfix2 HEAD)
     /
o-o-X (master HEAD)
     \ 
      q1a--q1b (quickfix1 HEAD)

This is best done on a clean working tree.
See git config --global rebase.autostash true, especially after Git 2.10.

What is the difference between JSF, Servlet and JSP?

The basic difference between Servlets and JSP is that in Servlets we write java code and in that we embed HTML code and there is just reverse case with JSP . In JSP we write HTML code and in that we embed java code using tags provided by JSP.

Change the background color in a twitter bootstrap modal?

For Angular(7+) Project:

::ng-deep .modal-backdrop.show {
    opacity: 0.7 !important;
}

Otherwise you can use:

.modal-backdrop.show {
    opacity: 0.7 !important;
}

Android - SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length

I have faced the same issue. I almost wasted almost couple of weeks to resolved this issue. Finally I had on doubt on myself and tried to create another project by copy and paste some startup files like SplashScreen & LoginScreen.

But with the same code still i was getting SPAN_EXCLUSIVE_EXCLUSIVE.

Then i have removed the handler code from splash screen and tried again and Wow its working. I am not getting SPAN_EXCLUSIVE_EXCLUSIVE issue in logcat.

I wondering, why it is? till the time did not get any other solution but by removing handler from splash screen it is working.

Try and update here if it is resolved or not.

Get the client IP address using PHP

The simplest way to get the visitor’s/client’s IP address is using the $_SERVER['REMOTE_ADDR'] or $_SERVER['REMOTE_HOST'] variables.

However, sometimes this does not return the correct IP address of the visitor, so we can use some other server variables to get the IP address.

The below both functions are equivalent with the difference only in how and from where the values are retrieved.

getenv() is used to get the value of an environment variable in PHP.

// Function to get the client IP address
function get_client_ip() {
    $ipaddress = '';
    if (getenv('HTTP_CLIENT_IP'))
        $ipaddress = getenv('HTTP_CLIENT_IP');
    else if(getenv('HTTP_X_FORWARDED_FOR'))
        $ipaddress = getenv('HTTP_X_FORWARDED_FOR');
    else if(getenv('HTTP_X_FORWARDED'))
        $ipaddress = getenv('HTTP_X_FORWARDED');
    else if(getenv('HTTP_FORWARDED_FOR'))
        $ipaddress = getenv('HTTP_FORWARDED_FOR');
    else if(getenv('HTTP_FORWARDED'))
       $ipaddress = getenv('HTTP_FORWARDED');
    else if(getenv('REMOTE_ADDR'))
        $ipaddress = getenv('REMOTE_ADDR');
    else
        $ipaddress = 'UNKNOWN';
    return $ipaddress;
}

$_SERVER is an array that contains server variables created by the web server.

// Function to get the client IP address
function get_client_ip() {
    $ipaddress = '';
    if (isset($_SERVER['HTTP_CLIENT_IP']))
        $ipaddress = $_SERVER['HTTP_CLIENT_IP'];
    else if(isset($_SERVER['HTTP_X_FORWARDED_FOR']))
        $ipaddress = $_SERVER['HTTP_X_FORWARDED_FOR'];
    else if(isset($_SERVER['HTTP_X_FORWARDED']))
        $ipaddress = $_SERVER['HTTP_X_FORWARDED'];
    else if(isset($_SERVER['HTTP_FORWARDED_FOR']))
        $ipaddress = $_SERVER['HTTP_FORWARDED_FOR'];
    else if(isset($_SERVER['HTTP_FORWARDED']))
        $ipaddress = $_SERVER['HTTP_FORWARDED'];
    else if(isset($_SERVER['REMOTE_ADDR']))
        $ipaddress = $_SERVER['REMOTE_ADDR'];
    else
        $ipaddress = 'UNKNOWN';
    return $ipaddress;
}

what is the difference between uint16_t and unsigned short int incase of 64 bit processor?

uint16_t is guaranteed to be a unsigned integer that is 16 bits large

unsigned short int is guaranteed to be a unsigned short integer, where short integer is defined by the compiler (and potentially compiler flags) you are currently using. For most compilers for x86 hardware a short integer is 16 bits large.

Also note that per the ANSI C standard only the minimum size of 16 bits is defined, the maximum size is up to the developer of the compiler

Minimum Type Limits

Any compiler conforming to the Standard must also respect the following limits with respect to the range of values any particular type may accept. Note that these are lower limits: an implementation is free to exceed any or all of these. Note also that the minimum range for a char is dependent on whether or not a char is considered to be signed or unsigned.

Type Minimum Range

signed char     -127 to +127
unsigned char      0 to 255
short int     -32767 to +32767
unsigned short int 0 to 65535

toggle show/hide div with button?

Look at jQuery Toggle

HTML:

<div id='content'>Hello World</div>
<input type='button' id='hideshow' value='hide/show'>

jQuery:

jQuery(document).ready(function(){
    jQuery('#hideshow').live('click', function(event) {        
         jQuery('#content').toggle('show');
    });
});

For versions of jQuery 1.7 and newer use

jQuery(document).ready(function(){
    jQuery('#hideshow').on('click', function(event) {        
        jQuery('#content').toggle('show');
    });
});

For reference, kindly check this demo

Gradle Build Android Project "Could not resolve all dependencies" error

write following statement in your app's build.gradle file.

com.android.support:appcompat-v7:18.0.+

That's it

How to write specific CSS for mozilla, chrome and IE

Place your css in the following script and paste it into your CSS file.

@media screen and (-webkit-min-device-pixel-ratio:0) { your complete css style }

For example: @media screen and (-webkit-min-device-pixel-ratio:0) { container { margin-top: 120px;} }

Works like a charm.

Display MessageBox in ASP

If you want to do it from code behind, try this:

System.Web.UI.ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "AlertBox", "alert('Message');", true);

Replace all whitespace characters

We can also use this if we want to change all multiple joined blank spaces with a single character:

str.replace(/\s+/g,'X');

See it in action here: https://regex101.com/r/d9d53G/1

Explanation

/ \s+ / g

  • \s+ matches any whitespace character (equal to [\r\n\t\f\v ])
  • + Quantifier — Matches between one and unlimited times, as many times as possible, giving back as needed (greedy)

  • Global pattern flags
    • g modifier: global. All matches (don't return after first match)

How to Update Multiple Array Elements in mongodb

The thread is very old, but I came looking for answer here hence providing new solution.

With MongoDB version 3.6+, it is now possible to use the positional operator to update all items in an array. See official documentation here.

Following query would work for the question asked here. I have also verified with Java-MongoDB driver and it works successfully.

.update(   // or updateMany directly, removing the flag for 'multi'
   {"events.profile":10},
   {$set:{"events.$[].handled":0}},  // notice the empty brackets after '$' opearor
   false,
   true
)

Hope this helps someone like me.

Counting repeated characters in a string in Python

If someone is looking for the simplest way without collections module. I guess this will be helpful:

>>> s = "asldaksldkalskdla"
>>> {i:s.count(i) for i in set(s)}
{'a': 4, 'd': 3, 'k': 3, 's': 3, 'l': 4}

or

>>> [(i,s.count(i)) for i in set(s)]
[('a', 4), ('k', 3), ('s', 3), ('l', 4), ('d', 3)]

Detect when browser receives file download

A very simple (and lame) one line solution is to use the window.onblur() event to close the loading dialog. Of course, if it takes too long and the user decides to do something else (like reading emails) the loading dialog will close.

How to detect when cancel is clicked on file input?

You can detect this only in limited circumstances. Specifically, in chrome if a file was selected earlier and then the file dialog is clicked and cancel clicked, Chrome clears the file and fires the onChange event.

https://code.google.com/p/chromium/issues/detail?id=2508

In this scenario, you can detect this by handling the onChange event and checking the files property.

uncaught syntaxerror unexpected token U JSON

Well, to all who actually can't find the error anywhere in your code, neither "undefined as it says in local storage nor null"..simply just comment out your code and write another one that actually removes the item in local storage ..after that ,u can comment or delet the current code and reset again the previous one by simply uncommenting it out (if u dint delet t ...if u did u can write it again:))

LocalStorage.setItem('Previous' , "removeprevious");  


LocalStorage.removeItem('Previous');   
 Console.log(LocalStorage.getItem('Previous'));

Console will show null and that it ..reset your code again if t doesn't work, dude!you got errors.

sorry for my English!

Link to Flask static files with url_for

In my case I had special instruction into nginx configuration file:

location ~ \.(js|css|png|jpg|gif|swf|ico|pdf|mov|fla|zip|rar)$ {
            try_files $uri =404;
    }

All clients have received '404' because nginx nothing known about Flask.

I hope it help someone.

When is a language considered a scripting language?

One division is

  • scripting = dynamically interpreted
  • normal = compiled

A dynamically interpreted language is interpreted at runtime whereas a compiled language is compiled before execution.

I should add that as Jörg has pointed out, the interpreted / compiled distinction is not a feature of the language, but of the execution engine.

You might also be interested in this explanation of Type system, which is related and focuses more on the language aspect, instead of the execution engine. Most scripting languages are dynamically typed, whereas "normal" languages are mostly statically typed.

In general the division of statically vs dynamically typed languages is better defined and has more implications on the usability of the language.

Why is the Visual Studio 2015/2017/2019 Test Runner not discovering my xUnit v2 tests

The most common culprit for me has been Visual Studio trying to run the tests using a different architecture than the library it's testing. Unfortunately there are multiple places where it seems this can go wrong.

In VS 2017, try creating a Run Settings file, e.g. Default.runsettings in your test project. If your main lib is x64, the contents should be:

<?xml version="1.0" encoding="utf-8"?>
<RunSettings>
  <RunConfiguration>
    <TargetPlatform>x64</TargetPlatform>
  </RunConfiguration>
</RunSettings>

Then choose this file from Test -> Test Settings -> Select Test Settings File.

Then, under Test -> Test Settings, Default Processor Architecture, choose the correct architecture again.

Be sure to Clean and Build the entire solution. You may need to close and reopen the Test Explorer window. Look for any additional errors in the Output -> Test window, for more clues about incorrect architecture types.

FYI additional Test Settings entries can be found here.

how to query LIST using linq

var persons = new List<Person>
    {
        new Person {ID = 1, Name = "jhon", Salary = 2500},
        new Person {ID = 2, Name = "Sena", Salary = 1500},
        new Person {ID = 3, Name = "Max", Salary = 5500},
        new Person {ID = 4, Name = "Gen", Salary = 3500}
    };

var acertainperson = persons.Where(p => p.Name == "jhon").First();
Console.WriteLine("{0}: {1} points",
    acertainperson.Name, acertainperson.Salary);

jhon: 2500 points

var doingprettywell = persons.Where(p => p.Salary > 2000);
            foreach (var person in doingprettywell)
            {
                Console.WriteLine("{0}: {1} points",
                    person.Name, person.Salary);
            }

jhon: 2500 points
Max: 5500 points
Gen: 3500 points

        var astupidcalc = from p in persons
                          where p.ID > 2
                          select new
                                     {
                                         Name = p.Name,
                                         Bobos = p.Salary*p.ID,
                                         Bobotype = "bobos"
                                     };
        foreach (var person in astupidcalc)
        {
            Console.WriteLine("{0}: {1} {2}",
                person.Name, person.Bobos, person.Bobotype);
        }

Max: 16500 bobos
Gen: 14000 bobos

Removing the textarea border in HTML

This one is great:

<style type="text/css">
textarea.test
{  
width: 100%;
height: 100%;
border-color: Transparent;     
}
</style>
<textarea class="test"></textarea>

Appending a line to a file only if it does not already exist

The answers using grep are wrong. You need to add an -x option to match the entire line otherwise lines like #text to add will still match when looking to add exactly text to add.

So the correct solution is something like:

grep -qxF 'include "/configs/projectname.conf"' foo.bar || echo 'include "/configs/projectname.conf"' >> foo.bar

View google chrome's cached pictures

%UserProfile%\Local Settings\Application Data\Google\Chrome\User Data\Default\Cache

paste this in your address bar and enter, you will get all the files

just rename the files extension into the extension which u r looking.

ie. open command prompt then

C:\>cd %UserProfile%\Local Settings\Application Data\Google\Chrome\User Data\Default\Cache

then

C:\Users\User\AppData\Local\Google\Chrome\User Data\Default\Cache>ren *.* *.jpg

Keyboard shortcut to change font size in Eclipse?

Take a look at this project: http://code.google.com/p/tarlog-plugins/downloads/detail?name=tarlog.eclipse.plugins_1.4.2.jar&can=2&q=

It has some other features, but most importantly, it has Ctrl++ and Ctrl+- to change the font size, it's awesome.

MySQL: Grant **all** privileges on database

To access from remote server to mydb database only

GRANT ALL PRIVILEGES ON mydb.* TO 'root'@'192.168.2.21';

To access from remote server to all databases.

GRANT ALL PRIVILEGES ON * . * TO 'root'@'192.168.2.21';

Plotting two variables as lines using ggplot2 on the same graph

The general approach is to convert the data to long format (using melt() from package reshape or reshape2) or gather()/pivot_longer() from the tidyr package:

library("reshape2")
library("ggplot2")

test_data_long <- melt(test_data, id="date")  # convert to long format

ggplot(data=test_data_long,
       aes(x=date, y=value, colour=variable)) +
       geom_line()

ggplot2 output

Also see this question on reshaping data from wide to long.

Error: unexpected symbol/input/string constant/numeric constant/SPECIAL in my code

If you are copy-pasting code into R, it sometimes won't accept some special characters such as "~" and will appear instead as a "?". So if a certain character is giving an error, make sure to use your keyboard to enter the character, or find another website to copy-paste from if that doesn't work.

Implement Validation for WPF TextBoxes

To get it done only with XAML you need to add Validation Rules for individual properties. But i would recommend you to go with code behind approach. In your code, define your specifications in properties setters and throw exceptions when ever it doesn't compliance to your specifications. And use error template to display your errors to user in UI. Your XAML will look like this

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Window.Resources>
    <Style x:Key="CustomTextBoxTextStyle" TargetType="TextBox">
        <Setter Property="Foreground" Value="Green" />
        <Setter Property="MaxLength" Value="40" />
        <Setter Property="Width" Value="392" />
        <Style.Triggers>
            <Trigger Property="Validation.HasError" Value="True">
                <Trigger.Setters>
                    <Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Self},Path=(Validation.Errors)[0].ErrorContent}"/>
                    <Setter Property="Background" Value="Red"/>
                </Trigger.Setters>
            </Trigger>
        </Style.Triggers>
    </Style>
</Window.Resources>
<Grid>
    <TextBox Name="tb2" Height="30" Width="400"
             Text="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, ValidatesOnExceptions=True}" 
             Style="{StaticResource CustomTextBoxTextStyle}"/>
</Grid>

Code Behind:

public partial class MainWindow : Window
{
    private ExampleViewModel m_ViewModel;
    public MainWindow()
    {
        InitializeComponent();
        m_ViewModel = new ExampleViewModel();
        DataContext = m_ViewModel;
    }
}


public class ExampleViewModel : INotifyPropertyChanged
{
    private string m_Name = "Type Here";
    public ExampleViewModel()
    {

    }

    public string Name
    {
        get
        {
            return m_Name;
        }
        set
        {
            if (String.IsNullOrEmpty(value))
            {
                throw new Exception("Name can not be empty.");
            }
            if (value.Length > 12)
            {
                throw new Exception("name can not be longer than 12 charectors");
            }
            if (m_Name != value)
            {
                m_Name = value;
                OnPropertyChanged("Name");
            }
        }
    }


    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

    }
}

How do I initialize a TypeScript Object with a JSON-Object?

My approach is slightly different. I do not copy properties into new instances, I just change the prototype of existing POJOs (may not work well on older browsers). Each class is responsible for providing a SetPrototypes method to set the prototoypes of any child objects, which in turn provide their own SetPrototypes methods.

(I also use a _Type property to get the class name of unknown objects but that can be ignored here)

class ParentClass
{
    public ID?: Guid;
    public Child?: ChildClass;
    public ListOfChildren?: ChildClass[];

    /**
     * Set the prototypes of all objects in the graph.
     * Used for recursive prototype assignment on a graph via ObjectUtils.SetPrototypeOf.
     * @param pojo Plain object received from API/JSON to be given the class prototype.
     */
    private static SetPrototypes(pojo: ParentClass): void
    {
        ObjectUtils.SetPrototypeOf(pojo.Child, ChildClass);
        ObjectUtils.SetPrototypeOfAll(pojo.ListOfChildren, ChildClass);
    }
}

class ChildClass
{
    public ID?: Guid;
    public GrandChild?: GrandChildClass;

    /**
     * Set the prototypes of all objects in the graph.
     * Used for recursive prototype assignment on a graph via ObjectUtils.SetPrototypeOf.
     * @param pojo Plain object received from API/JSON to be given the class prototype.
     */
    private static SetPrototypes(pojo: ChildClass): void
    {
        ObjectUtils.SetPrototypeOf(pojo.GrandChild, GrandChildClass);
    }
}

Here is ObjectUtils.ts:

/**
 * ClassType lets us specify arguments as class variables.
 * (where ClassType == window[ClassName])
 */
type ClassType = { new(...args: any[]): any; };

/**
 * The name of a class as opposed to the class itself.
 * (where ClassType == window[ClassName])
 */
type ClassName = string & {};

abstract class ObjectUtils
{
/**
 * Set the prototype of an object to the specified class.
 *
 * Does nothing if source or type are null.
 * Throws an exception if type is not a known class type.
 *
 * If type has the SetPrototypes method then that is called on the source
 * to perform recursive prototype assignment on an object graph.
 *
 * SetPrototypes is declared private on types because it should only be called
 * by this method. It does not (and must not) set the prototype of the object
 * itself - only the protoypes of child properties, otherwise it would cause a
 * loop. Thus a public method would be misleading and not useful on its own.
 * 
 * https://stackoverflow.com/questions/9959727/proto-vs-prototype-in-javascript
 */
public static SetPrototypeOf(source: any, type: ClassType | ClassName): any
{
    let classType = (typeof type === "string") ? window[type] : type;

    if (!source || !classType)
    {
        return source;
    }

    // Guard/contract utility
    ExGuard.IsValid(classType.prototype, "type", <any>type);

    if ((<any>Object).setPrototypeOf)
    {
        (<any>Object).setPrototypeOf(source, classType.prototype);
    }
    else if (source.__proto__)
    {
        source.__proto__ = classType.prototype.__proto__;
    }

    if (typeof classType["SetPrototypes"] === "function")
    {
        classType["SetPrototypes"](source);
    }

    return source;
}

/**
 * Set the prototype of a list of objects to the specified class.
 * 
 * Throws an exception if type is not a known class type.
 */
public static SetPrototypeOfAll(source: any[], type: ClassType): void
{
    if (!source)
    {
        return;
    }

    for (var i = 0; i < source.length; i++)
    {
        this.SetPrototypeOf(source[i], type);
    }
}
}

Usage:

let pojo = SomePlainOldJavascriptObjectReceivedViaAjax;

let parentObject = ObjectUtils.SetPrototypeOf(pojo, ParentClass);

// parentObject is now a proper ParentClass instance

Break a previous commit into multiple commits

Here is how to split one commit in IntelliJ IDEA, PyCharm, PhpStorm etc

  1. In Version Control log window, select the commit you would like to split, right click and select the Interactively Rebase from Here

  2. mark the one you want to split as edit, click Start Rebasing

  3. You should see a yellow tag is placed meaning that the HEAD is set to that commit. Right click on that commit, select Undo Commit

  4. Now those commits are back to staging area, you can then commit them separately. After all change has been committed, the old commit becomes inactive.

How to get 30 days prior to current date?

This is an ES6 version

let date = new Date()
let newDate = new Date(date.setDate(date.getDate()-30))
console.log(newDate.getMonth()+1 + '/' + newDate.getDate() + '/' + newDate.getFullYear() )

When to use DataContract and DataMember attributes?

A data contract is a formal agreement between a service and a client that abstractly describes the data to be exchanged.

Data contract can be explicit or implicit. Simple type such as int, string etc has an implicit data contract. User defined object are explicit or Complex type, for which you have to define a Data contract using [DataContract] and [DataMember] attribute.

A data contract can be defined as follows:

  • It describes the external format of data passed to and from service operations

  • It defines the structure and types of data exchanged in service messages

  • It maps a CLR type to an XML Schema
  • It defines how data types are serialized and deserialized. Through serialization, you convert an object into a sequence of bytes that can be transmitted over a network. Through deserialization, you reassemble an object from a sequence of bytes that you receive from a calling application.
  • It is a versioning system that allows you to manage changes to structured data

We need to include System.Runtime.Serialization reference to the project. This assembly holds the DataContract and DataMember attribute.

PPT to PNG with transparent background

One workaround that I have done is:

  • Ctrl + a to select everything in the slide
  • Ctrl + c to copy it
  • open GIMP (probably works in Photoshop or other software)
  • make a new image with a transparent background
  • Ctrl + v to paste all the vectors/text into the image
  • Export the image to a PNG or whatever format

It looks pretty much exactly the same as in Powerpoint, and the vectors/text are very clean with their transparency edges.

Subquery returned more than 1 value.This is not permitted when the subquery follows =,!=,<,<=,>,>= or when the subquery is used as an expression

Use In instead of =

 select * from dbo.books
 where isbn in (select isbn from dbo.lending 
                where act between @fdate and @tdate
                and stat ='close'
               )

or you can use Exists

SELECT t1.*,t2.*
FROM  books   t1 
WHERE  EXISTS ( SELECT * FROM dbo.lending t2 WHERE t1.isbn = t2.isbn and
                t2.act between @fdate and @tdate and t2.stat ='close' )

How to dynamically load a Python class

def import_class(cl):
    d = cl.rfind(".")
    classname = cl[d+1:len(cl)]
    m = __import__(cl[0:d], globals(), locals(), [classname])
    return getattr(m, classname)

How exactly does the python any() function work?

If you use any(lst) you see that lst is the iterable, which is a list of some items. If it contained [0, False, '', 0.0, [], {}, None] (which all have boolean values of False) then any(lst) would be False. If lst also contained any of the following [-1, True, "X", 0.00001] (all of which evaluate to True) then any(lst) would be True.

In the code you posted, x > 0 for x in lst, this is a different kind of iterable, called a generator expression. Before generator expressions were added to Python, you would have created a list comprehension, which looks very similar, but with surrounding []'s: [x > 0 for x in lst]. From the lst containing [-1, -2, 10, -4, 20], you would get this comprehended list: [False, False, True, False, True]. This internal value would then get passed to the any function, which would return True, since there is at least one True value.

But with generator expressions, Python no longer has to create that internal list of True(s) and False(s), the values will be generated as the any function iterates through the values generated one at a time by the generator expression. And, since any short-circuits, it will stop iterating as soon as it sees the first True value. This would be especially handy if you created lst using something like lst = range(-1,int(1e9)) (or xrange if you are using Python2.x). Even though this expression will generate over a billion entries, any only has to go as far as the third entry when it gets to 1, which evaluates True for x>0, and so any can return True.

If you had created a list comprehension, Python would first have had to create the billion-element list in memory, and then pass that to any. But by using a generator expression, you can have Python's builtin functions like any and all break out early, as soon as a True or False value is seen.

Two arrays in foreach loop

Use an associative array:

$code_names = array(
                    'tn' => 'Tunisia',
                    'us' => 'United States',
                    'fr' => 'France');

foreach($code_names as $code => $name) {
   //...
}

I believe that using an associative array is the most sensible approach as opposed to using array_combine() because once you have an associative array, you can simply use array_keys() or array_values() to get exactly the same array you had before.

MySQL SELECT last few days?

WHERE t.date >= DATE_ADD(CURDATE(), INTERVAL '-3' DAY);

use quotes on the -3 value

How can I use the HTML5 canvas element in IE?

Currently, ExplorerCanvas is the only option to emulate HTML5 canvas for IE6, 7, and 8. You're also right about its performance, which is pretty poor.

I found a particle simulatior that benchmarks the difference between true HTML5 canvas handling in Google Chrome, Safari, and Firefox, vs ExplorerCanvas in IE. The results show that the major browsers that do support the canvas tag run about 20 to 30 times faster than the emulated HTML5 in IE with ExplorerCanvas.

I doubt that anyone will go through the effort of creating an alternative because 1) excanvas.js is about as cleanly coded as it gets and 2) when IE9 is released all of the major browsers will finally support the canvas object. Hopefully, We'll get IE9 within a year

Eric @ www.webkrunk.com

Get startup type of Windows service using PowerShell

Use:

Get-Service BITS | Select StartType

Or use:

(Get-Service -Name BITS).StartType

Then

Set-Service BITS -StartupType xxx

[PowerShell 5.1]

What does AND 0xFF do?

Assuming your byte1 is a byte(8bits), When you do a bitwise AND of a byte with 0xFF, you are getting the same byte.

So byte1 is the same as byte1 & 0xFF

Say byte1 is 01001101 , then byte1 & 0xFF = 01001101 & 11111111 = 01001101 = byte1

If byte1 is of some other type say integer of 4 bytes, bitwise AND with 0xFF leaves you with least significant byte(8 bits) of the byte1.

Decompile .smali files on an APK

I second that.

Dex2jar will generate a WORKING jar, which you can add as your project source, with the xmls you got from apktool.

However, JDGUI generates .java files which have ,more often than not, errors.

It has got something to do with code obfuscation I guess.

For a boolean field, what is the naming convention for its getter/setter?

For a field named isCurrent, the correct getter / setter naming is setCurrent() / isCurrent() (at least that's what Eclipse thinks), which is highly confusing and can be traced back to the main problem:

Your field should not be called isCurrent in the first place. Is is a verb and verbs are inappropriate to represent an Object's state. Use an adjective instead, and suddenly your getter / setter names will make more sense:

private boolean current;

public boolean isCurrent(){
    return current;
}

public void setCurrent(final boolean current){
    this.current = current;
}

WAMP Cannot access on local network 403 Forbidden

To expand on RiggsFolly’s answer—or for anyone who is facing the same issue but is using Apache 2.2 or below—this format should work well:

Order Deny,Allow
Deny from all
Allow from 127.0.0.1 ::1
Allow from localhost
Allow from 192.168
Allow from 10
Satisfy Any

For more details on the format changes for Apache 2.4, the official Upgrading to 2.2 from 2.4 page is pretty clear & concise. Key point being:

The old access control idioms should be replaced by the new authentication mechanisms, although for compatibility with old configurations, the new module mod_access_compat is provided.

Which means, system admins around the world don’t necessarily have to panic about changing Apache 2.2 configs to be 2.4 compliant just yet.

How to get the directory of the currently running file?

Gustavo Niemeyer's answer is great. But in Windows, runtime proc is mostly in another dir, like this:

"C:\Users\XXX\AppData\Local\Temp"

If you use relative file path, like "/config/api.yaml", this will use your project path where your code exists.

"No rule to make target 'install'"... But Makefile exists

Could you provide a whole makefile? But right now I can tell - you should check that "install" target already exists. So, check Makefile whether it contains a

install: (anything there)

line. If not, there is no such target and so make has right. Probably you should use just "make" command to compile and then use it as is or install yourself, manually.

Install is not any standard of make, it is just a common target, that could exists, but not necessary.

Listing files in a directory matching a pattern in Java

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

public class CharCountFromAllFilesInFolder {

    public static void main(String[] args)throws IOException {

        try{

            //C:\Users\MD\Desktop\Test1

            System.out.println("Enter Your FilePath:");

            Scanner sc = new Scanner(System.in);

            Map<Character,Integer> hm = new TreeMap<Character, Integer>();

            String s1 = sc.nextLine();

            File file = new File(s1);

            File[] filearr = file.listFiles();

            for (File file2 : filearr) {
                System.out.println(file2.getName());
                FileReader fr = new FileReader(file2);
                BufferedReader br = new BufferedReader(fr);
                String s2 = br.readLine();
                for (int i = 0; i < s2.length(); i++) {
                    if(!hm.containsKey(s2.charAt(i))){
                        hm.put(s2.charAt(i), 1);
                    }//if
                    else{
                        hm.put(s2.charAt(i), hm.get(s2.charAt(i))+1);
                    }//else

                }//for2

                System.out.println("The Char Count: "+hm);
            }//for1

        }//try
        catch(Exception e){
            System.out.println("Please Give Correct File Path:");
        }//catch
    }
}

Using getResources() in non-activity class

We can use context Like this try now Where the parent is the ViewGroup.

Context context = parent.getContext();

How can I quickly sum all numbers in a file?

I couldn't just pass by... Here's my Haskell one-liner. It's actually quite readable:

sum <$> (read <$>) <$> lines <$> getContents

Unfortunately there's no ghci -e to just run it, so it needs the main function, print and compilation.

main = (sum <$> (read <$>) <$> lines <$> getContents) >>= print

To clarify, we read entire input (getContents), split it by lines, read as numbers and sum. <$> is fmap operator - we use it instead of usual function application because sure this all happens in IO. read needs an additional fmap, because it is also in the list.

$ ghc sum.hs
[1 of 1] Compiling Main             ( sum.hs, sum.o )
Linking sum ...
$ ./sum 
1
2
4
^D
7

Here's a strange upgrade to make it work with floats:

main = ((0.0 + ) <$> sum <$> (read <$>) <$> lines <$> getContents) >>= print
$ ./sum 
1.3
2.1
4.2
^D
7.6000000000000005

How to margin the body of the page (html)?

Html for content, CSS for style

<body style='margin-top:0;margin-left:0;margin-right:0;'>

Applying styles to tables with Twitter Bootstrap

Twitter bootstrap tables can be styled and well designed. You can style your table just adding some classes on your table and it’ll look nice. You might use it on your data reports, showing information, etc.

enter image description here You can use :

basic table
Striped rows
Bordered table
Hover rows
Condensed table
Contextual classes
Responsive tables

Striped rows Table :

    <table class="table table-striped" width="647">
    <thead>
    <tr>
    <th>#</th>
    <th>Name</th>
    <th>Address</th>
    <th>mail</th>
    </tr>
    </thead>
    <tbody>
    <tr>
    <td>1</td>
    <td>Thomas bell</td>
    <td>Brick lane, London</td>
    <td>[email protected]</td>
    </tr>
    <tr>
    <td height="29">2</td>
    <td>Yan Chapel</td>
    <td>Toronto Australia</td>
    <td>[email protected]</td>
    </tr>
    <tr>
    <td>3</td>
    <td>Pit Sampras</td>
    <td>Berlin, Germany</td>
    <td>Pit @yahoo.com</td>
    </tr>
    </tbody>
    </table>

Condensed table :

Compacting a table you need to add class class=”table table-condensed” .

    <table class="table table-condensed" width="647">
    <thead>
    <tr>
    <th>#</th>
    <th>Sample Name</th>
    <th>Address</th>
    <th>Mail</th>
    </tr>
    </thead>
    <tbody>
    <tr>
    <td>1</td>
    <td>Thomas bell</td>
    <td>Brick lane, London</td>
    <td>[email protected]</td>
    </tr>
    <tr>
    <td height="29">2</td>
    <td>Yan Chapel</td>
    <td>Toronto Australia</td>
    <td>[email protected]</td>
    </tr>
    <tr>
    <td>3</td>
    <td>Pit Sampras</td>
    <td>Berlin, Germany</td>
    <td>Pit @yahoo.com</td>
    </tr>
    <tr>
    <td></td>
    <td colspan="3" align="center"></td>
    </tr>
    </tbody>
    </table>

Ref : http://twitterbootstrap.org/twitter-bootstrap-table-example-tutorial

What's the difference between utf8_general_ci and utf8_unicode_ci?

There are two big difference the sorting and the character matching:

Sorting:

  • utf8mb4_general_ci removes all accents and sorts one by one which may create incorrect sort results.
  • utf8mb4_unicode_ci sorts accurate.

Character Matching

They match characters differently.

For example, in utf8mb4_unicode_ci you have i != i, but in utf8mb4_general_ci it holds i=i.

For example, imagine you have a row with name="Yilmaz". Then

select id from users where name='Yilmaz';

would return the row if collocation is utf8mb4_general_ci, but if it is collocated with utf8mb4_unicode_ci it would not return the row!

On the other hand we have that a=ª and ß=ss in utf8mb4_unicode_ci which is not the case in utf8mb4_general_ci. So imagine you have a row with name="ªßi", then

select id from users where name='assi';

would return the row if collocation is utf8mb4_unicode_ci, but would not return a row if collocation is set to utf8mb4_general_ci.

A full list of matches for each collocation may be found here.

What are the differences between JSON and JSONP?

“JSONP is JSON with extra code” would be too easy for the real world. No, you gotta have little discrepancies. What’s the fun in programming if everything just works?

Turns out JSON is not a subset of JavaScript. If all you do is take a JSON object and wrap it in a function call, one day you will be bitten by strange syntax errors, like I was today.

Check if record exists from controller in Rails

When you call Business.where(:user_id => current_user.id) you will get an array. This Array may have no objects or one or many objects in it, but it won't be null. Thus the check == nil will never be true.

You can try the following:

if Business.where(:user_id => current_user.id).count == 0

So you check the number of elements in the array and compare them to zero.

or you can try:

if Business.find_by_user_id(current_user.id).nil?

this will return one or nil.

How do I use disk caching in Picasso?

This is what I did. Works well.

First add the OkHttp to the gradle build file of the app module:

compile 'com.squareup.picasso:picasso:2.5.2'
compile 'com.squareup.okhttp3:okhttp:3.10.0'
compile 'com.jakewharton.picasso:picasso2-okhttp3-downloader:1.1.0'

Then make a class extending Application

import android.app.Application;

import com.jakewharton.picasso.OkHttp3Downloader;
import com.squareup.picasso.Picasso;

public class Global extends Application {
    @Override
    public void onCreate() {
        super.onCreate();

        Picasso.Builder builder = new Picasso.Builder(this);
        builder.downloader(new OkHttp3Downloader(this,Integer.MAX_VALUE));
        Picasso built = builder.build();
        built.setIndicatorsEnabled(true);
        built.setLoggingEnabled(true);
        Picasso.setSingletonInstance(built);

    }
}

add it to the Manifest file as follows :

<application
        android:name=".Global"
        .. >

</application>

Now use Picasso as you normally would. No changes.

EDIT:

if you want to use cached images only. Call the library like this. I've noticed that if we don't add the networkPolicy, images won't show up in an fully offline start even if they are cached. The code below solves the problem.

Picasso.with(this)
            .load(url)
            .networkPolicy(NetworkPolicy.OFFLINE)
            .into(imageView);

EDIT #2

the problem with the above code is that if you clear cache, Picasso will keep looking for it offline in cache and fail, the following code example looks at the local cache, if not found offline, it goes online and replenishes the cache.

Picasso.with(getActivity())
.load(imageUrl)
.networkPolicy(NetworkPolicy.OFFLINE)
.into(imageView, new Callback() {
    @Override
    public void onSuccess() {

    }

    @Override
    public void onError() {
        //Try again online if cache failed
        Picasso.with(getActivity())
                .load(posts.get(position).getImageUrl())
                .error(R.drawable.header)
                .into(imageView, new Callback() {
            @Override
            public void onSuccess() {

            }

            @Override
            public void onError() {
                Log.v("Picasso","Could not fetch image");
            }
        });
    }
});

vuetify center items into v-flex

<v-layout justify-center>
  <v-card-actions>
    <v-btn primary>
     <span>SignUp</span>
    </v-btn>`enter code here`
  </v-card-actions>
</v-layout>

What causes a java.lang.ArrayIndexOutOfBoundsException and how do I prevent it?

You could not iterate or store more data than the length of your array. In this case you could do like this:

for (int i = 0; i <= name.length - 1; i++) {
    // ....
}

Or this:

for (int i = 0; i < name.length; i++) {
    // ...
}

Play sound file in a web-page in the background

With me the problem was solved by removing the type attribute:

<embed name="myMusic" loop="true" hidden="true" src="Music.mp3"></embed>

Cerntainly not the cleanest way.

If you're using HTML5: MP3 isn't supported by Firefox. Wav and Ogg are though. Here you can find an overview of which browser support which type of audio: http://www.w3schools.com/html/html5_audio.asp

Android - How to download a file from a webserver

Simple kotlin version

fun download(link: String, path: String) {
    URL(link).openStream().use { input ->
        FileOutputStream(File(path)).use { output ->
            input.copyTo(output)
        }
    }
}

EDIT

or as extension

fun String.saveTo(path: String) {
    URL(this).openStream().use { input ->
        FileOutputStream(File(path)).use { output ->
            input.copyTo(output)
        }
    }
}

// ...

"http://example.site/document".saveTo("some/path/file")

Excel VBA For Each Worksheet Loop

You need to put the worksheet identifier in your range statements as shown below ...

 Option Explicit
 Dim ws As Worksheet, a As Range

Sub forEachWs()

For Each ws In ActiveWorkbook.Worksheets
Call resizingColumns
Next

End Sub

Sub resizingColumns()
ws.Range("A:A").ColumnWidth = 20.14
ws.Range("B:B").ColumnWidth = 9.71
ws.Range("C:C").ColumnWidth = 35.86
ws.Range("D:D").ColumnWidth = 30.57
ws.Range("E:E").ColumnWidth = 23.57
ws.Range("F:F").ColumnWidth = 21.43
ws.Range("G:G").ColumnWidth = 18.43
ws.Range("H:H").ColumnWidth = 23.86
ws.Range("i:I").ColumnWidth = 27.43
ws.Range("J:J").ColumnWidth = 36.71
ws.Range("K:K").ColumnWidth = 30.29
ws.Range("L:L").ColumnWidth = 31.14
ws.Range("M:M").ColumnWidth = 31
ws.Range("N:N").ColumnWidth = 41.14
ws.Range("O:O").ColumnWidth = 33.86
End Sub

Difference between @Before, @BeforeClass, @BeforeEach and @BeforeAll

Difference between each annotation are :

+-------------------------------------------------------------------------------------------------------+
¦                                       Feature                            ¦   Junit 4    ¦   Junit 5   ¦
¦--------------------------------------------------------------------------+--------------+-------------¦
¦ Execute before all test methods of the class are executed.               ¦ @BeforeClass ¦ @BeforeAll  ¦
¦ Used with static method.                                                 ¦              ¦             ¦
¦ For example, This method could contain some initialization code          ¦              ¦             ¦
¦-------------------------------------------------------------------------------------------------------¦
¦ Execute after all test methods in the current class.                     ¦ @AfterClass  ¦ @AfterAll   ¦
¦ Used with static method.                                                 ¦              ¦             ¦
¦ For example, This method could contain some cleanup code.                ¦              ¦             ¦
¦-------------------------------------------------------------------------------------------------------¦
¦ Execute before each test method.                                         ¦ @Before      ¦ @BeforeEach ¦
¦ Used with non-static method.                                             ¦              ¦             ¦
¦ For example, to reinitialize some class attributes used by the methods.  ¦              ¦             ¦
¦-------------------------------------------------------------------------------------------------------¦
¦ Execute after each test method.                                          ¦ @After       ¦ @AfterEach  ¦
¦ Used with non-static method.                                             ¦              ¦             ¦
¦ For example, to roll back database modifications.                        ¦              ¦             ¦
+-------------------------------------------------------------------------------------------------------+

Most of annotations in both versions are same, but few differs.

Reference

Order of Execution.

Dashed box -> optional annotation.

enter image description here

How to round up the result of integer division?

I do the following, handles any overflows:

var totalPages = totalResults.IsDivisble(recordsperpage) ? totalResults/(recordsperpage) : totalResults/(recordsperpage) + 1;

And use this extension for if there's 0 results:

public static bool IsDivisble(this int x, int n)
{
           return (x%n) == 0;
}

Also, for the current page number (wasn't asked but could be useful):

var currentPage = (int) Math.Ceiling(recordsperpage/(double) recordsperpage) + 1;

AngularJS POST Fails: Response for preflight has invalid HTTP status code 404

Ok so here's how I figured this out. It all has to do with CORS policy. Before the POST request, Chrome was doing a preflight OPTIONS request, which should be handled and acknowledged by the server prior to the actual request. Now this is really not what I wanted for such a simple server. Hence, resetting the headers client side prevents the preflight:

app.config(function ($httpProvider) {
  $httpProvider.defaults.headers.common = {};
  $httpProvider.defaults.headers.post = {};
  $httpProvider.defaults.headers.put = {};
  $httpProvider.defaults.headers.patch = {};
});

The browser will now send a POST directly. Hope this helps a lot of folks out there... My real problem was not understanding CORS enough.

Link to a great explanation: http://www.html5rocks.com/en/tutorials/cors/

Kudos to this answer for showing me the way.

What are the minimum margins most printers can handle?

The margins vary depending on the printer. In Windows GDI, you call the following functions to get the built-in margins, the "no-print zone":

GetDeviceCaps(hdc, PHYSICALWIDTH);
GetDeviceCaps(hdc, PHYSICALHEIGHT);
GetDeviceCaps(hdc, PHYSICALOFFSETX);
GetDeviceCaps(hdc, PHYSICALOFFSETY);

Printing right to the edge is called a "bleed" in the printing industry. The only laser printer I ever knew to print right to the edge was the Xerox 9700: 120 ppm, $500K in 1980.

How to check if curl is enabled or disabled

var_dump(extension_loaded('curl'));

do-while loop in R

Pretty self explanatory.

repeat{
  statements...
  if(condition){
    break
  }
}

Or something like that I would think. To get the effect of the do while loop, simply check for your condition at the end of the group of statements.

Finding the length of an integer in C

int returnIntLength(int value){
    int counter = 0;
    if(value < 0)
    {
        counter++;
        value = -value;
    }
    else if(value == 0)
        return 1;

    while(value > 0){
        value /= 10;
        counter++;
    }

    return counter;
}

I think this method is well suited for this task:

value and answers:

  • -50 -> 3 //it will count - as one character as well if you dont want to count minus then remove counter++ from 5th line.

  • 566666 -> 6

  • 0 -> 1

  • 505 -> 3

Java Generics With a Class & an Interface - Together

Actually, you can do what you want. If you want to provide multiple interfaces or a class plus interfaces, you have to have your wildcard look something like this:

<T extends ClassA & InterfaceB>

See the Generics Tutorial at sun.com, specifically the Bounded Type Parameters section, at the bottom of the page. You can actually list more than one interface if you wish, using & InterfaceName for each one that you need.

This can get arbitrarily complicated. To demonstrate, see the JavaDoc declaration of Collections#max, which (wrapped onto two lines) is:

public static <T extends Object & Comparable<? super T>> T
                                           max(Collection<? extends T> coll)

why so complicated? As said in the Java Generics FAQ: To preserve binary compatibility.

It looks like this doesn't work for variable declaration, but it does work when putting a generic boundary on a class. Thus, to do what you want, you may have to jump through a few hoops. But you can do it. You can do something like this, putting a generic boundary on your class and then:

class classB { }
interface interfaceC { }

public class MyClass<T extends classB & interfaceC> {
    Class<T> variable;
}

to get variable that has the restriction that you want. For more information and examples, check out page 3 of Generics in Java 5.0. Note, in <T extends B & C>, the class name must come first, and interfaces follow. And of course you can only list a single class.

trace a particular IP and port

Firstly, check the IP address that your application has bound to. It could only be binding to a local address, for example, which would mean that you'd never see it from a different machine regardless of firewall states.

You could try using a portscanner like nmap to see if the port is open and visible externally... it can tell you if the port is closed (there's nothing listening there), open (you should be able to see it fine) or filtered (by a firewall, for example).

How do I purge a linux mail box with huge number of emails?

On UNIX / Linux / Mac OS X you can copy and override files, can't you? So how about this solution:

cp /dev/null /var/mail/root

Convert list of ASCII codes to string (byte array) in Python

Shorter version of previous using map() function (works for python 2.7):

"".join(map(chr, myList))

Inheriting constructors

If your compiler supports C++11 standard, there is a constructor inheritance using using (pun intended). For more see Wikipedia C++11 article. You write:

class A
{
    public: 
        explicit A(int x) {}
};

class B: public A
{
     using A::A;
};

This is all or nothing - you cannot inherit only some constructors, if you write this, you inherit all of them. To inherit only selected ones you need to write the individual constructors manually and call the base constructor as needed from them.

Historically constructors could not be inherited in the C++03 standard. You needed to inherit them manually one by one by calling base implementation on your own.

How to downgrade the installed version of 'pip' on windows?

pip itself is just a normal python package. Thus you can install pip with pip.

Of cource, you don't want to affect the system's pip, install it inside a virtualenv.

pip install pip==1.2.1

Node.js EACCES error when listening on most ports

Check this reference link:

Give Safe User Permission To Use Port 80

Remember, we do NOT want to run your applications as the root user, but there is a hitch: your safe user does not have permission to use the default HTTP port (80). You goal is to be able to publish a website that visitors can use by navigating to an easy to use URL like http://ip:port/

Unfortunately, unless you sign on as root, you’ll normally have to use a URL like http://ip:port - where port number > 1024.

A lot of people get stuck here, but the solution is easy. There a few options but this is the one I like. Type the following commands:

sudo apt-get install libcap2-bin
sudo setcap cap_net_bind_service=+ep `readlink -f \`which node\``

Now, when you tell a Node application that you want it to run on port 80, it will not complain.

How to write to Console.Out during execution of an MSTest test

I found a solution of my own. I know that Andras answer is probably the most consistent with MSTEST, but I didn't feel like refactoring my code.

[TestMethod]
public void OneIsOne()
{
    using (ConsoleRedirector cr = new ConsoleRedirector())
    {
        Assert.IsFalse(cr.ToString().Contains("New text"));
        /* call some method that writes "New text" to stdout */
        Assert.IsTrue(cr.ToString().Contains("New text"));
    }
}

The disposable ConsoleRedirector is defined as:

internal class ConsoleRedirector : IDisposable
{
    private StringWriter _consoleOutput = new StringWriter();
    private TextWriter _originalConsoleOutput;
    public ConsoleRedirector()
    {
        this._originalConsoleOutput = Console.Out;
        Console.SetOut(_consoleOutput);
    }
    public void Dispose()
    {
        Console.SetOut(_originalConsoleOutput);
        Console.Write(this.ToString());
        this._consoleOutput.Dispose();
    }
    public override string ToString()
    {
        return this._consoleOutput.ToString();
    }
}

Android Studio suddenly cannot resolve symbols

I faced similar problem but I followed following steps in my case :-

1).inside project under .idea folder open modules.xml. 2).check if there are two entries for same iml file. 3).delete one of duplicate entry and close android studio or build gradle file again.

In my case it worked. Hope it helps

Windows equivalent of $export

There is not an equivalent statement for export in Windows Command Prompt. In Windows the environment is copied so when you exit from the session (from a called command prompt or from an executable that set a variable) the variable in Windows get lost. You can set it in user registry or in machine registry via setx but you won't see it if you not start a new command prompt.

Creating default object from empty value in PHP?

Try this if you have array and add objects to it.

$product_details = array();

foreach ($products_in_store as $key => $objects) {
  $product_details[$key] = new stdClass(); //the magic
  $product_details[$key]->product_id = $objects->id; 
   //see new object member created on the fly without warning.
}

This sends ARRAY of Objects for later use~!

How to disable 'X-Frame-Options' response header in Spring Security?

If you're using Spring Boot, the simplest way to disable the Spring Security default headers is to use security.headers.* properties. In particular, if you want to disable the X-Frame-Options default header, just add the following to your application.properties:

security.headers.frame=false

There is also security.headers.cache, security.headers.content-type, security.headers.hsts and security.headers.xss properties that you can use. For more information, take a look at SecurityProperties.

How to properly validate input values with React.JS?

Use onChange={this.handleChange.bind(this, "name") method and value={this.state.fields["name"]} on input text field and below that create span element to show error, see the below example.

export default class Form extends Component {

  constructor(){
    super()
    this.state ={
       fields: {
         name:'',
         email: '',
         message: ''
       },
       errors: {},
       disabled : false
    }
  }

  handleValidation(){
       let fields = this.state.fields;
       let errors = {};
       let formIsValid = true;

       if(!fields["name"]){
          formIsValid = false;
          errors["name"] = "Name field cannot be empty";
       }

       if(typeof fields["name"] !== "undefined" && !fields["name"] === false){
          if(!fields["name"].match(/^[a-zA-Z]+$/)){
             formIsValid = false;
             errors["name"] = "Only letters";
          }
       }

       if(!fields["email"]){
          formIsValid = false;
          errors["email"] = "Email field cannot be empty";
       }

       if(typeof fields["email"] !== "undefined" && !fields["email"] === false){
          let lastAtPos = fields["email"].lastIndexOf('@');
          let lastDotPos = fields["email"].lastIndexOf('.');

          if (!(lastAtPos < lastDotPos && lastAtPos > 0 && fields["email"].indexOf('@@') === -1 && lastDotPos > 2 && (fields["email"].length - lastDotPos) > 2)) {
             formIsValid = false;
             errors["email"] = "Email is not valid";
           }
      }

      if(!fields["message"]){
         formIsValid = false;
         errors["message"] = " Message field cannot be empty";
      }

      this.setState({errors: errors});
      return formIsValid;
  }

  handleChange(field, e){
      let fields = this.state.fields;
      fields[field] = e.target.value;
      this.setState({fields});
  }

  handleSubmit(e){
      e.preventDefault();
      if(this.handleValidation()){
          console.log('validation successful')
        }else{
          console.log('validation failed')
        }
  }

  render(){
    return (
      <form onSubmit={this.handleSubmit.bind(this)} method="POST">
          <div className="row">
            <div className="col-25">
                <label htmlFor="name">Name</label>
            </div>
            <div className="col-75">
                <input type="text" placeholder="Enter Name"  refs="name" onChange={this.handleChange.bind(this, "name")} value={this.state.fields["name"]}/>
                <span style={{color: "red"}}>{this.state.errors["name"]}</span>
            </div>
          </div>
          <div className="row">
            <div className="col-25">
              <label htmlFor="exampleInputEmail1">Email address</label>
            </div>
            <div className="col-75">
                <input type="email" placeholder="Enter Email" refs="email" aria-describedby="emailHelp" onChange={this.handleChange.bind(this, "email")} value={this.state.fields["email"]}/>
                <span style={{color: "red"}}>{this.state.errors["email"]}</span>
            </div>
          </div>
          <div className="row">
            <div className="col-25">
                <label htmlFor="message">Message</label>
            </div>
            <div className="col-75">
                <textarea type="text" placeholder="Enter Message" rows="5" refs="message" onChange={this.handleChange.bind(this, "message")} value={this.state.fields["message"]}></textarea>
                <span style={{color: "red"}}>{this.state.errors["message"]}</span>
            </div>
          </div>
          <div className="row">
            <button type="submit" disabled={this.state.disabled}>{this.state.disabled ? 'Sending...' : 'Send'}</button>
          </div>
      </form>
    )
  }
}

What is HTML5 ARIA?

What is ARIA?

ARIA emerged as a way to address the accessibility problem of using a markup language intended for documents, HTML, to build user interfaces (UI). HTML includes a great many features to deal with documents (P, h3,UL,TABLE) but only basic UI elements such as A, INPUT and BUTTON. Windows and other operating systems support APIs that allow (Assistive Technology) AT to access the functionality of UI controls. Internet Explorer and other browsers map the native HTML elements to the accessibility API, but the html controls are not as rich as the controls common on desktop operating systems, and are not enough for modern web applications Custom controls can extend html elements to provide the rich UI needed for modern web applications. Before ARIA, the browser had no way to expose this extra richness to the accessibility API or AT. The classic example of this issue is adding a click handler to an image. It creates what appears to be a clickable button to a mouse user, but is still just an image to a keyboard or AT user.

The solution was to create a set of attributes that allow developers to extend HTML with UI semantics. The ARIA term for a group of HTML elements that have custom functionality and use ARIA attributes to map these functions to accessibility APIs is a “Widget. ARIA also provides a means for authors to document the role of content itself, which in turn, allows AT to construct alternate navigation mechanisms for the content that are much easier to use than reading the full text or only iterating over a list of the links.

It is important to remember that in simple cases, it is much preferred to use native HTML controls and style them rather than using ARIA. That is don’t reinvent wheels, or checkboxes, if you don’t have to.

Fortunately, ARIA markup can be added to existing sites without changing the behavior for mainstream users. This greatly reduces the cost of modifying and testing the website or application.

Check if a Python list item contains a string inside another string

I did a search, which requires you to input a certain value, then it will look for a value from the list which contains your input:

my_list = ['abc-123',
        'def-456',
        'ghi-789',
        'abc-456'
        ]

imp = raw_input('Search item: ')

for items in my_list:
    val = items
    if any(imp in val for items in my_list):
        print(items)

Try searching for 'abc'.

Cannot set property 'display' of undefined

document.getElementsByClassName('btn-pageMenu') delivers a nodeList. You should use: document.getElementsByClassName('btn-pageMenu')[0].style.display (if it's the first element from that list you want to change.

If you want to change style.display for all nodes loop through the list:

var elems = document.getElementsByClassName('btn-pageMenu');
for (var i=0;i<elems.length;i+=1){
  elems[i].style.display = 'block';
}

to be complete: if you use jquery it is as simple as:

?$('.btn-pageMenu').css('display'???????????????????????????,'block');??????

Is it possible to focus on a <div> using JavaScript focus() function?

Yes - this is possible. In order to do it, you need to assign a tabindex...

<div tabindex="0">Hello World</div>

A tabindex of 0 will put the tag "in the natural tab order of the page". A higher number will give it a specific order of priority, where 1 will be the first, 2 second and so on.

You can also give a tabindex of -1, which will make the div only focus-able by script, not the user.

_x000D_
_x000D_
document.getElementById('test').onclick = function () {_x000D_
    document.getElementById('scripted').focus();_x000D_
};
_x000D_
div:focus {_x000D_
    background-color: Aqua;_x000D_
}
_x000D_
<div>Element X (not focusable)</div>_x000D_
<div tabindex="0">Element Y (user or script focusable)</div>_x000D_
<div tabindex="-1" id="scripted">Element Z (script-only focusable)</div>_x000D_
<div id="test">Set Focus To Element Z</div>
_x000D_
_x000D_
_x000D_

Obviously, it is a shame to have an element you can focus by script that you can't focus by other input method (especially if a user is keyboard only or similarly constrained). There are also a whole bunch of standard elements that are focusable by default and have semantic information baked in to assist users. Use this knowledge wisely.

How to update specific key's value in an associative array in PHP?

This a single solution, in where your_field is a field that will set and new_value is a new value field, that can a function or a single value

foreach ($array as $key => $item) {
   $item["your_field"] = "new_value";
   $array[$key] = $item;
}

In your case new_value will be a date() function

How to parse a CSV in a Bash script?

index=1
value=2
awk -F"," -v i=$index -v v=$value '$(i)==v' file

Is there a Google Sheets formula to put the name of the sheet into a cell?

I got this to finally work in a semi-automatic fashion without the use of scripts... but it does take up 3 cells to pull it off. Borrowing from a bit from previous answers, I start with a cell that has nothing more than =NOW() it in to show the time. For example, we'll put this into cell A1...

=NOW()

This function updates automatically every minute. In the next cell, put a pointer formula using the sheets own name to point to the previous cell. For example, we'll put this in A2...

='Sheet Name'!A1

Cell formatting aside, cell A1 and A2 should at this point display the same content... namely the current time.

And, the last cell is the part I'm borrowing from previous solutions using a regex expression to pull the fomula from the second cell and then strip out the name of the sheet from said formula. For example, we'll put this into cell A3...

=REGEXREPLACE(FORMULATEXT(A2),"='?([^']+)'?!.*","$1")

At this point, the resultant value displayed in A3 should be the name of the sheet.

From my experience, as soon as the name of the sheet is changed, the formula in A2 is immediately updated. However that's not enough to trigger A3 to update. But, every minute when cell A1 recalculates the time, the result of the formula in cell A2 is subsequently updated and then that in turn triggers A3 to update with the new sheet name. It's not a compact solution... but it does seem to work.

Handling JSON Post Request in Go

I was driving myself crazy with this exact problem. My JSON Marshaller and Unmarshaller were not populating my Go struct. Then I found the solution at https://eager.io/blog/go-and-json:

"As with all structs in Go, it’s important to remember that only fields with a capital first letter are visible to external programs like the JSON Marshaller."

After that, my Marshaller and Unmarshaller worked perfectly!

Send multipart/form-data files with angular using $http

Here's an updated answer for Angular 4 & 5. TransformRequest and angular.identity were dropped. I've also included the ability to combine files with JSON data in one request.

Angular 5 Solution:

import {HttpClient} from '@angular/common/http';

uploadFileToUrl(files, restObj, uploadUrl): Promise<any> {
  // Note that setting a content-type header
  // for mutlipart forms breaks some built in
  // request parsers like multer in express.
  const options = {} as any; // Set any options you like
  const formData = new FormData();

  // Append files to the virtual form.
  for (const file of files) {
    formData.append(file.name, file)
  }

  // Optional, append other kev:val rest data to the form.
  Object.keys(restObj).forEach(key => {
    formData.append(key, restObj[key]);
  });

  // Send it.
  return this.httpClient.post(uploadUrl, formData, options)
    .toPromise()
    .catch((e) => {
      // handle me
    });
}

Angular 4 Solution:

// Note that these imports below are deprecated in Angular 5
import {Http, RequestOptions} from '@angular/http';

uploadFileToUrl(files, restObj, uploadUrl): Promise<any> {
  // Note that setting a content-type header
  // for mutlipart forms breaks some built in
  // request parsers like multer in express.
  const options = new RequestOptions();
  const formData = new FormData();

  // Append files to the virtual form.
  for (const file of files) {
    formData.append(file.name, file)
  }

  // Optional, append other kev:val rest data to the form.
  Object.keys(restObj).forEach(key => {
    formData.append(key, restObj[key]);
  });

  // Send it.
  return this.http.post(uploadUrl, formData, options)
    .toPromise()
    .catch((e) => {
      // handle me
    });
}

How to label each equation in align environment?

Within the environment align from the package amsmath it is possible to combine the use of \label and \tag for each equation or line. For example, the code:

\documentclass{article}
\usepackage{amsmath}

\begin{document}
Write
\begin{align}
x+y\label{eq:eq1}\tag{Aa}\\
x+z\label{eq:eq2}\tag{Bb}\\
y-z\label{eq:eq3}\tag{Cc}\\
y-2z\nonumber
\end{align}
then cite \eqref{eq:eq1} and \eqref{eq:eq2} or \eqref{eq:eq3} separately.
\end{document}

produces:

screenshot of output

How can I transform string to UTF-8 in C#?

string utf8String = "Acción";
string propEncodeString = string.Empty;

byte[] utf8_Bytes = new byte[utf8String.Length];
for (int i = 0; i < utf8String.Length; ++i)
{
   utf8_Bytes[i] = (byte)utf8String[i];
}

propEncodeString = Encoding.UTF8.GetString(utf8_Bytes, 0, utf8_Bytes.Length);

Output should look like

Acción

day’s displays day's

call DecodeFromUtf8();

private static void DecodeFromUtf8()
{
    string utf8_String = "day’s";
    byte[] bytes = Encoding.Default.GetBytes(utf8_String);
    utf8_String = Encoding.UTF8.GetString(bytes);
}

How to change the background colour's opacity in CSS

Use RGB values combined with opacity to get the transparency that you wish.

For instance,

<div style=" background: rgb(255, 0, 0) ; opacity: 0.2;">&nbsp;</div>
<div style=" background: rgb(255, 0, 0) ; opacity: 0.4;">&nbsp;</div>
<div style=" background: rgb(255, 0, 0) ; opacity: 0.6;">&nbsp;</div>
<div style=" background: rgb(255, 0, 0) ; opacity: 0.8;">&nbsp;</div>
<div style=" background: rgb(255, 0, 0) ; opacity: 1;">&nbsp;</div>

Similarly, with actual values without opacity, will give the below.

<div style=" background: rgb(243, 191, 189) ; ">&nbsp;</div>
<div style=" background: rgb(246, 143, 142) ; ">&nbsp;</div>
<div style=" background: rgb(249, 95 , 94)  ; ">&nbsp;</div>
<div style=" background: rgb(252, 47, 47)   ; ">&nbsp;</div>
<div style=" background: rgb(255, 0, 0)     ; ">&nbsp;</div>

You can have a look at this WORKING EXAMPLE.

Now, if we specifically target your issue, here is the WORKING DEMO SPECIFIC TO YOUR ISSUE.

The HTML

<div class="social">
    <img src="http://www.google.co.in/images/srpr/logo4w.png" border="0" />
</div>

The CSS:

social img{
    opacity:0.5;
}
.social img:hover {
    opacity:1;
    background-color:black;
    cursor:pointer;
    background: rgb(255, 0, 0) ; opacity: 0.5;
}

Hope this helps Now.

Order of items in classes: Fields, Properties, Constructors, Methods

This is an old but still very relevant question, so I'll add this: What's the first thing you look for when you open up a class file that you may or may not have read before? Fields? Properties? I've realized from experience that almost invariably I go hunting for the constructors, because the most basic thing to understand is how this object is constructed.

Therefore, I've started putting constructors first in class files, and the result has been psychologically very positive. The standard recommendation of putting constructors after a bunch of other things feels dissonant.

The upcoming primary constructor feature in C# 6 provides evidence that the natural place for a constructor is at the very top of a class - in fact primary constructors are specified even before the open brace.

It's funny how much of a difference a reordering like this makes. It reminds me of how using statements used to be ordered - with the System namespaces first. Visual Studio's "Organize Usings" command used this order. Now usings are just ordered alphabetically, with no special treatment given to System namespaces. The result just feels simpler and cleaner.

Java Date cut off time information

Have you looked at the DateUtils truncate method in Apache Commons Lang?

Date truncatedDate = DateUtils.truncate(new Date(), Calendar.DATE);

will remove the time element.

Maven not found in Mac OSX mavericks

  1. Download Maven from here.
  2. Extract the tar.gz you just downloaded to the location you want (ex:/Users/admin/Maven).
  3. Open the Terminal.
  4. Type " cd " to go to your home folder.
  5. Type "touch .bash_profile".
  6. Type "open -e .bash_profile" to open .bash_profile in TextEdit.
  7. Type the following in the TextEditor

alias mvn='/[Your file location]/apache-maven-x.x.x/bin/mvn'
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdkx.x.x_xx.jdk/Contents/Home/

(Make sure there are no speech marks or apostrophe's) 8. Make sure you fill the required data (ex your file location and version number).

  1. Save your changes
  2. Type ". .bash_profile" to reload .bash_profile and update any functions you add. (*make sure you separate the dots with a single space).
  3. Type mvn -version

If successful you should see the following:

Apache Maven 3.1.1
Maven home: /Users/admin/Maven/apache-maven-3.1.1
Java version: 1.7.0_51, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "10.9.1", arch: "x86_64", family: "mac"

How to print a dictionary's key?

In Python 3:

# A simple dictionary
x = {'X':"yes", 'Y':"no", 'Z':"ok"}

# To print a specific key (for example key at index 1)
print([key for key in x.keys()][1])

# To print a specific value (for example value at index 1)
print([value for value in x.values()][1])

# To print a pair of a key with its value (for example pair at index 2)
print(([key for key in x.keys()][2], [value for value in x.values()][2]))

# To print a key and a different value (for example key at index 0 and value at index 1)
print(([key for key in x.keys()][0], [value for value in x.values()][1]))

# To print all keys and values concatenated together
print(''.join(str(key) + '' + str(value) for key, value in x.items()))

# To print all keys and values separated by commas
print(', '.join(str(key) + ', ' + str(value) for key, value in x.items()))

# To print all pairs of (key, value) one at a time
for e in range(len(x)):
    print(([key for key in x.keys()][e], [value for value in x.values()][e]))

# To print all pairs (key, value) in a tuple
print(tuple(([key for key in x.keys()][i], [value for value in x.values()][i]) for i in range(len(x))))

Unfortunately MyApp has stopped. How can I solve this?

If your app for some reason crashes without good stacktrace. Try debug it from first line, and go line by line until crash. Then you will have answer, which line is causing you trouble. Proably you could then wrapp it into try catch block and print error output.

Button Listener for button in fragment in android

This works for me.

private OnClickListener mDisconnectListener;
mDisconnectListener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

        }
    };

...

... onCreateView(...){

mButtonDisconnect = (Button) rootView.findViewById(R.id.button_disconnect);
mButtonDisconnect.setOnClickListener(mDisconnectListener);
...
}

How to resolve TypeError: Cannot convert undefined or null to object

Replace

if (typeof obj === 'undefined') { return undefined;} // return undefined for undefined
if (obj === 'null') { return null;} // null unchanged

with

if (obj === undefined) { return undefined;} // return undefined for undefined 
if (obj === null) { return null;} // null unchanged

What is the difference between Left, Right, Outer and Inner Joins?

There are three basic types of join:

  • INNER join compares two tables and only returns results where a match exists. Records from the 1st table are duplicated when they match multiple results in the 2nd. INNER joins tend to make result sets smaller, but because records can be duplicated this isn't guaranteed.
  • CROSS join compares two tables and return every possible combination of rows from both tables. You can get a lot of results from this kind of join that might not even be meaningful, so use with caution.
  • OUTER join compares two tables and returns data when a match is available or NULL values otherwise. Like with INNER join, this will duplicate rows in the one table when it matches multiple records in the other table. OUTER joins tend to make result sets larger, because they won't by themselves remove any records from the set. You must also qualify an OUTER join to determine when and where to add the NULL values:
    • LEFT means keep all records from the 1st table no matter what and insert NULL values when the 2nd table doesn't match.
    • RIGHT means the opposite: keep all records from the 2nd table no matter what and insert NULL values whent he 1st table doesn't match.
    • FULL means keep all records from both tables, and insert a NULL value in either table if there is no match.

Often you see will the OUTER keyword omitted from the syntax. Instead it will just be "LEFT JOIN", "RIGHT JOIN", or "FULL JOIN". This is done because INNER and CROSS joins have no meaning with respect to LEFT, RIGHT, or FULL, and so these are sufficient by themselves to unambiguously indicate an OUTER join.

Here is an example of when you might want to use each type:

  • INNER: You want to return all records from the "Invoice" table, along with their corresponding "InvoiceLines". This assumes that every valid Invoice will have at least one line.
  • OUTER: You want to return all "InvoiceLines" records for a particular Invoice, along with their corresponding "InventoryItem" records. This is a business that also sells service, such that not all InvoiceLines will have an IventoryItem.
  • CROSS: You have a digits table with 10 rows, each holding values '0' through '9'. You want to create a date range table to join against, so that you end up with one record for each day within the range. By CROSS-joining this table with itself repeatedly you can create as many consecutive integers as you need (given you start at 10 to 1st power, each join adds 1 to the exponent). Then use the DATEADD() function to add those values to your base date for the range.

Summernote image upload

I tested this code and Works

Javascript

<script>
$(document).ready(function() {
  $('#summernote').summernote({
    height: 200,
    onImageUpload: function(files, editor, welEditable) {
      sendFile(files[0], editor, welEditable);
    }
  });

  function sendFile(file, editor, welEditable) {
    data = new FormData();
    data.append("file", file);
    $.ajax({
      data: data,
      type: "POST",
      url: "Your URL POST (php)",
      cache: false,
      contentType: false,
      processData: false,
      success: function(url) {
        editor.insertImage(welEditable, url);
      }
    });
  }
});
</script>

PHP

if ($_FILES['file']['name']) {
  if (!$_FILES['file']['error']) {
    $name = md5(rand(100, 200));
    $ext = pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION);
    $filename = $name.
    '.'.$ext;
    $destination = '/assets/images/'.$filename; //change this directory
    $location = $_FILES["file"]["tmp_name"];
    move_uploaded_file($location, $destination);
    echo 'http://test.yourdomain.al/images/'.$filename; //change this URL
  } else {
    echo $message = 'Ooops!  Your upload triggered the following error:  '.$_FILES['file']['error'];
  }
}

Update:

After 0.7.0 onImageUpload should be inside callbacks option as mentioned by @tugberk

$('#summernote').summernote({
    height: 200,
    callbacks: {
        onImageUpload: function(files, editor, welEditable) {
            sendFile(files[0], editor, welEditable);
        }
    }
});

IF-THEN-ELSE statements in postgresql

In general, an alternative to case when ... is coalesce(nullif(x,bad_value),y) (that cannot be used in OP's case). For example,

select coalesce(nullif(y,''),x), coalesce(nullif(x,''),y), *
from (     (select 'abc' as x, '' as y)
 union all (select 'def' as x, 'ghi' as y)
 union all (select '' as x, 'jkl' as y)
 union all (select null as x, 'mno' as y)
 union all (select 'pqr' as x, null as y)
) q

gives:

 coalesce | coalesce |  x  |  y  
----------+----------+-----+-----
 abc      | abc      | abc | 
 ghi      | def      | def | ghi
 jkl      | jkl      |     | jkl
 mno      | mno      |     | mno
 pqr      | pqr      | pqr | 
(5 rows)

Integer division with remainder in JavaScript?

ES6 introduces the new Math.trunc method. This allows to fix @MarkElliot's answer to make it work for negative numbers too:

var div = Math.trunc(y/x);
var rem = y % x;

Note that Math methods have the advantage over bitwise operators that they work with numbers over 231.

What does `unsigned` in MySQL mean and when to use it?

MySQL says:

All integer types can have an optional (nonstandard) attribute UNSIGNED. Unsigned type can be used to permit only nonnegative numbers in a column or when you need a larger upper numeric range for the column. For example, if an INT column is UNSIGNED, the size of the column's range is the same but its endpoints shift from -2147483648 and 2147483647 up to 0 and 4294967295.

When do I use it ?

Ask yourself this question: Will this field ever contain a negative value?
If the answer is no, then you want an UNSIGNED data type.

A common mistake is to use a primary key that is an auto-increment INT starting at zero, yet the type is SIGNED, in that case you’ll never touch any of the negative numbers and you are reducing the range of possible id's to half.

throwing exceptions out of a destructor

Unlike constructors, where throwing exceptions can be a useful way to indicate that object creation succeeded, exceptions should not be thrown in destructors.

The problem occurs when an exception is thrown from a destructor during the stack unwinding process. If that happens, the compiler is put in a situation where it doesn’t know whether to continue the stack unwinding process or handle the new exception. The end result is that your program will be terminated immediately.

Consequently, the best course of action is just to abstain from using exceptions in destructors altogether. Write a message to a log file instead.

Accessing the web page's HTTP Headers in JavaScript

Unfortunately, there isn't an API to give you the HTTP response headers for your initial page request. That was the original question posted here. It has been repeatedly asked, too, because some people would like to get the actual response headers of the original page request without issuing another one.


For AJAX Requests:

If an HTTP request is made over AJAX, it is possible to get the response headers with the getAllResponseHeaders() method. It's part of the XMLHttpRequest API. To see how this can be applied, check out the fetchSimilarHeaders() function below. Note that this is a work-around to the problem that won't be reliable for some applications.

myXMLHttpRequest.getAllResponseHeaders();

This will not give you information about the original page request's HTTP response headers, but it could be used to make educated guesses about what those headers were. More on that is described next.


Getting header values from the Initial Page Request:

This question was first asked several years ago, asking specifically about how to get at the original HTTP response headers for the current page (i.e. the same page inside of which the javascript was running). This is quite a different question than simply getting the response headers for any HTTP request. For the initial page request, the headers aren't readily available to javascript. Whether the header values you need will be reliably and sufficiently consistent if you request the same page again via AJAX will depend on your particular application.

The following are a few suggestions for getting around that problem.


1. Requests on Resources which are largely static

If the response is largely static and the headers are not expected to change much between requests, you could make an AJAX request for the same page you're currently on and assume that they're they are the same values which were part of the page's HTTP response. This could allow you to access the headers you need using the nice XMLHttpRequest API described above.

function fetchSimilarHeaders (callback) {
    var request = new XMLHttpRequest();
    request.onreadystatechange = function () {
        if (request.readyState === XMLHttpRequest.DONE) {
            //
            // The following headers may often be similar
            // to those of the original page request...
            //
            if (callback && typeof callback === 'function') {
                callback(request.getAllResponseHeaders());
            }
        }
    };

    //
    // Re-request the same page (document.location)
    // We hope to get the same or similar response headers to those which 
    // came with the current page, but we have no guarantee.
    // Since we are only after the headers, a HEAD request may be sufficient.
    //
    request.open('HEAD', document.location, true);
    request.send(null);
}

This approach will be problematic if you truly have to rely on the values being consistent between requests, since you can't fully guarantee that they are the same. It's going to depend on your specific application and whether you know that the value you need is something that won't be changing from one request to the next.


2. Make Inferences

There are some BOM properties (Browser Object Model) which the browser determines by looking at the headers. Some of these properties reflect HTTP headers directly (e.g. navigator.userAgent is set to the value of the HTTP User-Agent header field). By sniffing around the available properties you might be able to find what you need, or some clues to indicate what the HTTP response contained.


3. Stash them

If you control the server side, you can access any header you like as you construct the full response. Values could be passed to the client with the page, stashed in some markup or perhaps in an inlined JSON structure. If you wanted to have every HTTP request header available to your javascript, you could iterate through them on the server and send them back as hidden values in the markup. It's probably not ideal to send header values this way, but you could certainly do it for the specific value you need. This solution is arguably inefficient, too, but it would do the job if you needed it.

Up, Down, Left and Right arrow keys do not trigger KeyDown event

In order to capture keystrokes in a Forms control, you must derive a new class that is based on the class of the control that you want, and you override the ProcessCmdKey().

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
    //handle your keys here
}

Example :

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
    //capture up arrow key
    if (keyData == Keys.Up )
    {
        MessageBox.Show("You pressed Up arrow key");
        return true;
    }

    return base.ProcessCmdKey(ref msg, keyData);
}

Full source...Arrow keys in C#

Vayne

List of all index & index columns in SQL Server DB

The correct One is here (All the above posts will give Cartesian product result when we have more then one index on a table)

select s.name, t.name, i.name, c.name from sys.tables t
inner join sys.schemas s on t.schema_id = s.schema_id
inner join sys.indexes i on i.object_id = t.object_id
inner join sys.index_columns ic on ic.object_id = t.object_id 
                                  AND i.index_id = ic.index_id
inner join sys.columns c on c.object_id = t.object_id 
                                  and  ic.column_id = c.column_id
where i.index_id > 0    
 and i.type in (1, 2) -- clustered & nonclustered only
 and i.is_primary_key = 0 -- do not include PK indexes
 and i.is_unique_constraint = 0 -- do not include UQ
 and i.is_disabled = 0
 and i.is_hypothetical = 0
 and ic.key_ordinal > 0
 AND  t.name = 'DimCustomer'
order by ic.key_ordinal

Eclipse JUnit - possible causes of seeing "initializationError" in Eclipse window

My problem was that my parent class had no @Test methodes. I used there only some utilities. When I declared it abstract it works.

Difference between agile and iterative and incremental development

  • Iterative - you don't finish a feature in one go. You are in a code >> get feedback >> code >> ... cycle. You keep iterating till done.
  • Incremental - you build as much as you need right now. You don't over-engineer or add flexibility unless the need is proven. When the need arises, you build on top of whatever already exists. (Note: differs from iterative in that you're adding new things.. vs refining something).
  • Agile - you are agile if you value the same things as listed in the agile manifesto. It also means that there is no standard template or checklist or procedure to "do agile". It doesn't overspecify.. it just states that you can use whatever practices you need to "be agile". Scrum, XP, Kanban are some of the more prescriptive 'agile' methodologies because they share the same set of values. Continuous and early feedback, frequent releases/demos, evolve design, etc.. hence they can be iterative and incremental.

Ignore 'Security Warning' running script from command line

I made this powershell script to unblock all files on a share on my server

Get-ChildItem "\\ServerName\e$\MyDirectory\" -Recurse -File | % {
       Unblock-File -Path $_.FullName
}

Sharing a URL with a query string on Twitter

This will Work For You

http://twitter.com/share?text=text goes here&url=http://url goes here&hashtags=hashtag1,hashtag2,hashtag3

Here is a Live Example About it


http://twitter.com/share?text=Im Sharing on Twitter&url=https://stackoverflow.com/users/2943186/youssef-subehi&hashtags=stackoverflow,example,youssefusf

Count all values in a matrix greater than a value

There are many ways to achieve this, like flatten-and-filter or simply enumerate, but I think using Boolean/mask array is the easiest one (and iirc a much faster one):

>>> y = np.array([[123,24123,32432], [234,24,23]])
array([[  123, 24123, 32432],
       [  234,    24,    23]])
>>> b = y > 200
>>> b
array([[False,  True,  True],
       [ True, False, False]], dtype=bool)
>>> y[b]
array([24123, 32432,   234])
>>> len(y[b])
3
>>>> y[b].sum()
56789

Update:

As nneonneo has answered, if all you want is the number of elements that passes threshold, you can simply do:

>>>> (y>200).sum()
3

which is a simpler solution.


Speed comparison with filter:

### use boolean/mask array ###

b = y > 200

%timeit y[b]
100000 loops, best of 3: 3.31 us per loop

%timeit y[y>200]
100000 loops, best of 3: 7.57 us per loop

### use filter ###

x = y.ravel()
%timeit filter(lambda x:x>200, x)
100000 loops, best of 3: 9.33 us per loop

%timeit np.array(filter(lambda x:x>200, x))
10000 loops, best of 3: 21.7 us per loop

%timeit filter(lambda x:x>200, y.ravel())
100000 loops, best of 3: 11.2 us per loop

%timeit np.array(filter(lambda x:x>200, y.ravel()))
10000 loops, best of 3: 22.9 us per loop

*** use numpy.where ***

nb = np.where(y>200)
%timeit y[nb]
100000 loops, best of 3: 2.42 us per loop

%timeit y[np.where(y>200)]
100000 loops, best of 3: 10.3 us per loop

Failed to connect to mysql at 127.0.0.1:3306 with user root access denied for user 'root'@'localhost'(using password:YES)

no idea how this happened, but i had the same problem. I had to reset my root password: http://www.jovicailic.org/2012/04/reset-forgotten-mysql-root-password-under-windows/

But after my databases that i had previously were either dropped or the new connection did not connect to them. Either way i couldn't access them via workbench. But i could use MySQL again, which was a win for me

How to loop over files in directory and change path and add suffix to filename

Looks like you're trying to execute a windows file (.exe) Surely you ought to be using powershell. Anyway on a Linux bash shell a simple one-liner will suffice.

[/home/$] for filename in /Data/*.txt; do for i in {0..3}; do ./MyProgam.exe  Data/filenameLogs/$filename_log$i.txt; done done

Or in a bash

#!/bin/bash

for filename in /Data/*.txt; 
   do
     for i in {0..3}; 
       do ./MyProgam.exe Data/filename.txt Logs/$filename_log$i.txt; 
     done 
 done

How to execute an SSIS package from .NET?

Here is how to set variables in the package from code -

using Microsoft.SqlServer.Dts.Runtime;

private void Execute_Package()
    {           
        string pkgLocation = @"c:\test.dtsx";

        Package pkg;
        Application app;
        DTSExecResult pkgResults;
        Variables vars;

        app = new Application();
        pkg = app.LoadPackage(pkgLocation, null);

        vars = pkg.Variables;
        vars["A_Variable"].Value = "Some value";               

        pkgResults = pkg.Execute(null, vars, null, null, null);

        if (pkgResults == DTSExecResult.Success)
            Console.WriteLine("Package ran successfully");
        else
            Console.WriteLine("Package failed");
    }

Zipping a file in bash fails

Run dos2unix or similar utility on it to remove the carriage returns (^M).

This message indicates that your file has dos-style lineendings:

-bash: /backup/backup.sh: /bin/bash^M: bad interpreter: No such file or directory 

Utilities like dos2unix will fix it:

 dos2unix <backup.bash >improved-backup.sh 

Or, if no such utility is installed, you can accomplish the same thing with translate:

tr -d "\015\032" <backup.bash >improved-backup.sh 

As for how those characters got there in the first place, @MadPhysicist had some good comments.

How do I obtain a Query Execution Plan in SQL Server?

Here's one important thing to know in addition to everything said before.

Query plans are often too complex to be represented by the built-in XML column type which has a limitation of 127 levels of nested elements. That is one of the reasons why sys.dm_exec_query_plan may return NULL or even throw an error in earlier MS SQL versions, so generally it's safer to use sys.dm_exec_text_query_plan instead. The latter also has a useful bonus feature of selecting a plan for a particular statement rather than the whole batch. Here's how you use it to view plans for currently running statements:

SELECT p.query_plan
FROM sys.dm_exec_requests AS r
OUTER APPLY sys.dm_exec_text_query_plan(
                r.plan_handle,
                r.statement_start_offset,
                r.statement_end_offset) AS p

The text column in the resulting table is however not very handy compared to an XML column. To be able to click on the result to be opened in a separate tab as a diagram, without having to save its contents to a file, you can use a little trick (remember you cannot just use CAST(... AS XML)), although this will only work for a single row:

SELECT Tag = 1, Parent = NULL, [ShowPlanXML!1!!XMLTEXT] = query_plan
FROM sys.dm_exec_text_query_plan(
                -- set these variables or copy values
                -- from the results of the above query
                @plan_handle,
                @statement_start_offset,
                @statement_end_offset)
FOR XML EXPLICIT

How to generate a random string of 20 characters

You may use the class java.util.Random with method

char c = (char)(rnd.nextInt(128-32))+32 

20x to get Bytes, which you interpret as ASCII. If you're fine with ASCII.

32 is the offset, from where the characters are printable in general.

For loop in multidimensional javascript array

var cubes = [["string", "string"], ["string", "string"]];

for(var i = 0; i < cubes.length; i++) {
    for(var j = 0; j < cubes[i].length; j++) {
        console.log(cubes[i][j]);
    }
}

VSCode Change Default Terminal

I just type following keywords in the opened terminal;

  1. powershell
  2. bash
  3. cmd
  4. node
  5. python (or python3)

See details in the below image. (VSCode version 1.19.1 - windows 10 OS) enter image description here

It works on VS Code Mac as well. I tried it with VSCode (Version 1.20.1)

Is there a no-duplicate List implementation out there?

The documentation for collection interfaces says:

Set — a collection that cannot contain duplicate elements.
List — an ordered collection (sometimes called a sequence). Lists can contain duplicate elements.

So if you don't want duplicates, you probably shouldn't use a list.

How an 'if (A && B)' statement is evaluated?

In C and C++, the && and || operators "short-circuit". That means that they only evaluate a parameter if required. If the first parameter to && is false, or the first to || is true, the rest will not be evaluated.

The code you posted is safe, though I question why you'd include an empty else block.

How to verify CuDNN installation?

Run ./mnistCUDNN in /usr/src/cudnn_samples_v7/mnistCUDNN

Here is an example:

cudnnGetVersion() : 7005 , CUDNN_VERSION from cudnn.h : 7005 (7.0.5)
Host compiler version : GCC 5.4.0
There are 1 CUDA capable devices on your machine :
device 0 : sms 30  Capabilities 6.1, SmClock 1645.0 Mhz, MemSize (Mb) 24446, MemClock 4513.0 Mhz, Ecc=0,    boardGroupID=0
Using device 0

Float to String format specifier

In C#, float is an alias for System.Single (a bit like intis an alias for System.Int32).

Changing upload_max_filesize on PHP

Are you using a shared hosting provider? It could be master settings overriding anything you're trying to change. Have you tried adding those into your .htaccess?

php_value upload_max_filesize 10M
php_value post_max_size 10M

iterating quickly through list of tuples

I wonder whether the below method is what you want.

You can use defaultdict.

>>> from collections import defaultdict
>>> s = [('red',1), ('blue',2), ('red',3), ('blue',4), ('red',1), ('blue',4)]
>>> d = defaultdict(list)
>>> for k, v in s:
       d[k].append(v)    
>>> sorted(d.items())
[('blue', [2, 4, 4]), ('red', [1, 3, 1])]

How do I connect to a SQL Server 2008 database using JDBC?

You can try configure SQL server:

  1. Step 1: Open SQL server 20xx Configuration Manager
  2. Step 2: Click Protocols for SQL.. in SQL server configuration. Then, right click TCP/IP, choose Properties
  3. Step 3: Click tab IP Address, Edit All TCP. Port is 1433

NOTE: ALL TCP port is 1433 Finally, restart the server.

How to merge every two lines into one from the command line?

Another solutions using vim (just for reference).

Solution 1:

Open file in vim vim filename, then execute command :% normal Jj

This command is very easy to understand:

  • % : for all the lines,
  • normal : execute normal command
  • Jj : execute Join command, then jump to below line

After that, save the file and exit with :wq

Solution 2:

Execute the command in shell, vim -c ":% normal Jj" filename, then save the file and exit with :wq.

How do you install Boost on MacOS?

In order to avoid troubles compiling third party libraries that need boost installed in your system, run this:

sudo port install boost +universal

Re-render React component when prop changes

You could use KEY unique key (combination of the data) that changes with props, and that component will be rerendered with updated props.

ValueError: setting an array element with a sequence

In my case , I got this Error in Tensorflow , Reason was i was trying to feed a array with different length or sequences :

example :

import tensorflow as tf

input_x = tf.placeholder(tf.int32,[None,None])



word_embedding = tf.get_variable('embeddin',shape=[len(vocab_),110],dtype=tf.float32,initializer=tf.random_uniform_initializer(-0.01,0.01))

embedding_look=tf.nn.embedding_lookup(word_embedding,input_x)

with tf.Session() as tt:
    tt.run(tf.global_variables_initializer())

    a,b=tt.run([word_embedding,embedding_look],feed_dict={input_x:example_array})
    print(b)

And if my array is :

example_array = [[1,2,3],[1,2]]

Then i will get error :

ValueError: setting an array element with a sequence.

but if i do padding then :

example_array = [[1,2,3],[1,2,0]]

Now it's working.

Error in finding last used cell in Excel with VBA

However this question is seeking to find the last row using VBA, I think it would be good to include an array formula for worksheet function as this gets visited frequently:

{=ADDRESS(MATCH(INDEX(D:D,MAX(IF(D:D<>"",ROW(D:D)-ROW(D1)+1)),1),D:D,0),COLUMN(D:D))}

You need to enter the formula without brackets and then hit Shift + Ctrl + Enter to make it an array formula.

This will give you address of last used cell in the column D.

What are the retransmission rules for TCP?

There's no fixed time for retransmission. Simple implementations estimate the RTT (round-trip-time) and if no ACK to send data has been received in 2x that time then they re-send.

They then double the wait-time and re-send once more if again there is no reply. Rinse. Repeat.

More sophisticated systems make better estimates of how long it should take for the ACK as well as guesses about exactly which data has been lost.

The bottom-line is that there is no hard-and-fast rule about exactly when to retransmit. It's up to the implementation. All retransmissions are triggered solely by the sender based on lack of response from the receiver.

TCP never drops data so no, there is no way to indicate a server should forget about some segment.

Replace all occurrences of a String using StringBuilder?

Here is an in place replaceAll that will modify the passed in StringBuilder. I thought that I would post this as I was looking to do replaceAll with out creating a new String.

public static void replaceAll(StringBuilder sb, Pattern pattern, String replacement) {
    Matcher m = pattern.matcher(sb);
    while(m.find()) {
        sb.replace(m.start(), m.end(), replacement);
    }
}

I was shocked how simple the code to do this was (for some reason I thought changing the StringBuilder while using the matcher would throw of the group start/end but it does not).

This is probably faster than the other regex answers because the pattern is already compiled and your not creating a new String but I didn't do any benchmarking.

How do I count occurrence of duplicate items in array

this code will return duplicate value in same array

$array = array(12,43,66,21,56,43,43,78,78,100,43,43,43,21);
foreach($arr as $key=>$item){
  if(array_count_values($arr)[$item] > 1){
     echo "Found Matched value : ".$item." <br />";
  }
}

How to sleep the thread in node.js without affecting other threads?

When working with async functions or observables provided by 3rd party libraries, for example Cloud firestore, I've found functions the waitFor method shown below (TypeScript, but you get the idea...) to be helpful when you need to wait on some process to complete, but you don't want to have to embed callbacks within callbacks within callbacks nor risk an infinite loop.

This method is sort of similar to a while (!condition) sleep loop, but yields asynchronously and performs a test on the completion condition at regular intervals till true or timeout.

export const sleep = (ms: number) => {
    return new Promise(resolve => setTimeout(resolve, ms))
}
/**
 * Wait until the condition tested in a function returns true, or until 
 * a timeout is exceeded.
 * @param interval The frenequency with which the boolean function contained in condition is called.
 * @param timeout  The maximum time to allow for booleanFunction to return true
 * @param booleanFunction:  A completion function to evaluate after each interval. waitFor will return true as soon as the completion function returns true.   
 */
export const waitFor = async function (interval: number, timeout: number,
    booleanFunction: Function): Promise<boolean> {
    let elapsed = 1;
    if (booleanFunction()) return true;
    while (elapsed < timeout) {
        elapsed += interval;
        await sleep(interval);
        if (booleanFunction()) {
            return true;
        }
    }
    return false;
}

The say you have a long running process on your backend you want to complete before some other task is undertaken. For example if you have a function that totals a list of accounts, but you want to refresh the accounts from the backend before you calculate, you can do something like this:

async recalcAccountTotals() : number {
     this.accountService.refresh();   //start the async process.
     if (this.accounts.dirty) {
           let updateResult = await waitFor(100,2000,()=> {return !(this.accounts.dirty)})
     }
 if(!updateResult) { 
      console.error("Account refresh timed out, recalc aborted");
      return NaN;
    }
 return ... //calculate the account total. 
}

How to Generate Unique ID in Java (Integer)?

int uniqueId = 0;

int getUniqueId()
{
    return uniqueId++;
}

Add synchronized if you want it to be thread safe.

How to iterate std::set?

Another example for the C++11 standard:

set<int> data;
data.insert(4);
data.insert(5);

for (const int &number : data)
  cout << number;

Xampp localhost/dashboard

Type in your URL localhost/[name of your folder in htdocs]

Check if table exists and if it doesn't exist, create it in SQL Server 2008

EDITED

You can look into sys.tables for checking existence desired table:

IF  NOT EXISTS (SELECT * FROM sys.tables
WHERE name = N'YourTable' AND type = 'U')

BEGIN
CREATE TABLE [SchemaName].[YourTable](
    ....
    ....
    ....
) 

END