Programs & Examples On #Cross domain policy

Cross-domain policy refers to the browser restrictions on script, stylesheet, and plugin execution across domains, protocols, and ports.

How to call external url in jquery?

google the javascript same origin policy

in a nutshell, the url you are trying to use must have the same root and protocol. so http://yoursite.com cannot access https://yoursite.com or http://anothersite.com

is you absolutely MUST bypass this protection (which is at the browser level, as galimy pointed out), consider the ProxyPass module for your favorite web server.

http://localhost:50070 does not work HADOOP

First all need to do is start hadoop nodes and Trackers, simply by typing start-all.sh on ur terminal. To check all the trackers and nodes are started write 'jps' command. if everything is fine and working, go to your browser type the following url http://localhost:50070

How To Add An "a href" Link To A "div"?

Can't you surround it with an a tag?

  <a href="#"><div id="buttonOne">
        <div id="linkedinB">
            <img src="img/linkedinB.png" width="40" height="40">
        </div>
  </div></a>

How to start automatic download of a file in Internet Explorer?

I hate when sites complicate download so much and use hacks instead of a good old link.

Dead simple version:

<a href="file.zip">Start automatic download!</a>

It works! In every browser!


If you want to download a file that is usually displayed inline (such as an image) then HTML5 has a download attribute that forces download of the file. It also allows you to override filename (although there is a better way to do it):

<a href="report-generator.php" download="result.xls">Download</a>

Version with a "thanks" page:

If you want to display "thanks" after download, then use:

<a href="file.zip" 
   onclick="if (event.button==0) 
     setTimeout(function(){document.body.innerHTML='thanks!'},500)">
 Start automatic download!
</a>

Function in that setTimeout might be more advanced and e.g. download full page via AJAX (but don't navigate away from the page — don't touch window.location or activate other links).

The point is that link to download is real, can be copied, dragged, intercepted by download accelerators, gets :visited color, doesn't re-download if page is left open after browser restart, etc.

That's what I use for ImageOptim

Which way is best for creating an object in JavaScript? Is `var` necessary before an object property?

There are a many ways to create your objects in JavaScript. Using a constructer function to create an object or object literal notation is using alot in JavaScript. Also creating an instance of Object and then adding properties and methods to it, there are three common ways to do create objects in JavaScript.

Constructer functions

There are built-in constructer functions that we all may use them time to time, like Date(), Number(), Boolean() etc, all constructer functions start with Capital letter, in the meantime we can create custom constructor function in JavaScript like this:

function Box (Width, Height, fill) {  
  this.width = Width;  // The width of the box 
  this.height = Height;  // The height of the box 
  this.fill = true;  // Is it filled or not?
}  

and you can invoke it, simply using new(), to create a new instance of the constructor, create something like below and call the constructor function with filled parameters:

var newBox = new Box(8, 12, true);  

Object literals

Using object literals are very used case creating object in JavaScript, this an example of creating a simple object, you can assign anything to your object properties as long as they are defined:

var person = { 
    name: "Alireza",
    surname: "Dezfoolian"
    nose: 1,  
    feet: 2,  
    hands: 2,
    cash: null
};  

Prototyping

After creating an Object, you can prototype more members to that, for example adding colour to our Box, we can do this:

Box.prototype.colour = 'red';

What does "javax.naming.NoInitialContextException" mean?

It basically means that the application wants to perform some "naming operations" (e.g. JNDI or LDAP lookups), and it didn't have sufficient information available to be able to create a connection to the directory server. As the docs for the exception state,

This exception is thrown when no initial context implementation can be created. The policy of how an initial context implementation is selected is described in the documentation of the InitialContext class.

And if you dutifully have a look at the javadocs for InitialContext, they describe quite well how the initial context is constructed, and what your options are for supplying the address/credentials/etc.

If you have a go at creating the context and get stuck somewhere else, please post back explaining what you've done so far and where you're running aground.

Android: How to detect double-tap?

Realization single and double click

public abstract class DoubleClickListener implements View.OnClickListener {

private static final long DOUBLE_CLICK_TIME_DELTA = 200;

private long lastClickTime = 0;

private View view;

private Handler handler = new Handler();
private Runnable runnable = new Runnable() {
    @Override
    public void run() {
        onSingleClick(view);
    }
};

private void runTimer(){
    handler.removeCallbacks(runnable);
    handler.postDelayed(runnable,DOUBLE_CLICK_TIME_DELTA);
}

@Override
public void onClick(View view) {
    this.view = view;
    long clickTime = System.currentTimeMillis();
    if (clickTime - lastClickTime < DOUBLE_CLICK_TIME_DELTA){
        handler.removeCallbacks(runnable);
        lastClickTime = 0;
        onDoubleClick(view);
    } else {
        runTimer();
        lastClickTime = clickTime;
    }
}

public abstract void onSingleClick(View v);
public abstract void onDoubleClick(View v);

}

What are the differences between numpy arrays and matrices? Which one should I use?

Numpy matrices are strictly 2-dimensional, while numpy arrays (ndarrays) are N-dimensional. Matrix objects are a subclass of ndarray, so they inherit all the attributes and methods of ndarrays.

The main advantage of numpy matrices is that they provide a convenient notation for matrix multiplication: if a and b are matrices, then a*b is their matrix product.

import numpy as np

a = np.mat('4 3; 2 1')
b = np.mat('1 2; 3 4')
print(a)
# [[4 3]
#  [2 1]]
print(b)
# [[1 2]
#  [3 4]]
print(a*b)
# [[13 20]
#  [ 5  8]]

On the other hand, as of Python 3.5, NumPy supports infix matrix multiplication using the @ operator, so you can achieve the same convenience of matrix multiplication with ndarrays in Python >= 3.5.

import numpy as np

a = np.array([[4, 3], [2, 1]])
b = np.array([[1, 2], [3, 4]])
print(a@b)
# [[13 20]
#  [ 5  8]]

Both matrix objects and ndarrays have .T to return the transpose, but matrix objects also have .H for the conjugate transpose, and .I for the inverse.

In contrast, numpy arrays consistently abide by the rule that operations are applied element-wise (except for the new @ operator). Thus, if a and b are numpy arrays, then a*b is the array formed by multiplying the components element-wise:

c = np.array([[4, 3], [2, 1]])
d = np.array([[1, 2], [3, 4]])
print(c*d)
# [[4 6]
#  [6 4]]

To obtain the result of matrix multiplication, you use np.dot (or @ in Python >= 3.5, as shown above):

print(np.dot(c,d))
# [[13 20]
#  [ 5  8]]

The ** operator also behaves differently:

print(a**2)
# [[22 15]
#  [10  7]]
print(c**2)
# [[16  9]
#  [ 4  1]]

Since a is a matrix, a**2 returns the matrix product a*a. Since c is an ndarray, c**2 returns an ndarray with each component squared element-wise.

There are other technical differences between matrix objects and ndarrays (having to do with np.ravel, item selection and sequence behavior).

The main advantage of numpy arrays is that they are more general than 2-dimensional matrices. What happens when you want a 3-dimensional array? Then you have to use an ndarray, not a matrix object. Thus, learning to use matrix objects is more work -- you have to learn matrix object operations, and ndarray operations.

Writing a program that mixes both matrices and arrays makes your life difficult because you have to keep track of what type of object your variables are, lest multiplication return something you don't expect.

In contrast, if you stick solely with ndarrays, then you can do everything matrix objects can do, and more, except with slightly different functions/notation.

If you are willing to give up the visual appeal of NumPy matrix product notation (which can be achieved almost as elegantly with ndarrays in Python >= 3.5), then I think NumPy arrays are definitely the way to go.

PS. Of course, you really don't have to choose one at the expense of the other, since np.asmatrix and np.asarray allow you to convert one to the other (as long as the array is 2-dimensional).


There is a synopsis of the differences between NumPy arrays vs NumPy matrixes here.

How do I display a decimal value to 2 decimal places?

None of these did exactly what I needed, to force 2 d.p. and round up as 0.005 -> 0.01

Forcing 2 d.p. requires increasing the precision by 2 d.p. to ensure we have at least 2 d.p.

then rounding to ensure we do not have more than 2 d.p.

Math.Round(exactResult * 1.00m, 2, MidpointRounding.AwayFromZero)

6.665m.ToString() -> "6.67"

6.6m.ToString() -> "6.60"

npm ERR! network getaddrinfo ENOTFOUND

I had incorrectly typed in the address as

http://addressOfProxy.8080

instead of

http://addressOfProxy:8080  

(Notice the colon before the port number 8080.)

Entity Framework 6 Code first Default value

Lets consider you have a class name named Products and you have a IsActive field. just you need a create constructor :

Public class Products
{
    public Products()
    {
       IsActive = true;
    }
 public string Field1 { get; set; }
 public string Field2 { get; set; }
 public bool IsActive { get; set; }
}

Then your IsActive default value is True!

Edite :

if you want to do this with SQL use this command :

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Blog>()
        .Property(b => b.IsActive)
        .HasDefaultValueSql("true");
}

Getting the application's directory from a WPF application

I tried this:

    label1.Content = Directory.GetCurrentDirectory();

and get also the directory.

How to query for Xml values and attributes from table in SQL Server?

I've been trying to do something very similar but not using the nodes. However, my xml structure is a little different.

You have it like this:

<Metrics>
    <Metric id="TransactionCleanupThread.RefundOldTrans" type="timer" ...>

If it were like this instead:

<Metrics>
    <Metric>
        <id>TransactionCleanupThread.RefundOldTrans</id>
        <type>timer</type>
        .
        .
        .

Then you could simply use this SQL statement.

SELECT
    Sqm.SqmId,
    Data.value('(/Sqm/Metrics/Metric/id)[1]', 'varchar(max)') as id,
    Data.value('(/Sqm/Metrics/Metric/type)[1]', 'varchar(max)') AS type,
    Data.value('(/Sqm/Metrics/Metric/unit)[1]', 'varchar(max)') AS unit,
    Data.value('(/Sqm/Metrics/Metric/sum)[1]', 'varchar(max)') AS sum,
    Data.value('(/Sqm/Metrics/Metric/count)[1]', 'varchar(max)') AS count,
    Data.value('(/Sqm/Metrics/Metric/minValue)[1]', 'varchar(max)') AS minValue,
    Data.value('(/Sqm/Metrics/Metric/maxValue)[1]', 'varchar(max)') AS maxValue,
    Data.value('(/Sqm/Metrics/Metric/stdDeviation)[1]', 'varchar(max)') AS stdDeviation,
FROM Sqm

To me this is much less confusing than using the outer apply or cross apply.

I hope this helps someone else looking for a simpler solution!

Could not load file or assembly 'System.Data.SQLite'

This is very simple if you are not using SQLite:

You can delete the SQLite DLLs from your solution's bin folders, then from the folder where you reference ELMAH. Rebuild, and your app won't try to load this DLL that you are not using.

Use Excel pivot table as data source for another Pivot Table

In a new sheet (where you want to create a new pivot table) press the key combination (Alt+D+P). In the list of data source options choose "Microsoft Excel list of database". Click Next and select the pivot table that you want to use as a source (select starting with the actual headers of the fields). I assume that this range is rather static and if you refresh the source pivot and it changes it's size you would have to re-size the range as well. Hope this helps.

C# Clear all items in ListView

How about

DataSource = null;
DataBind();

How to pass extra variables in URL with WordPress

This was the only way I could get this to work

add_action('init','add_query_args');
function add_query_args()
{ 
    add_query_arg( 'var1', 'val1' );
}

http://codex.wordpress.org/Function_Reference/add_query_arg

npm install gives error "can't find a package.json file"

Check this link for steps on how to install express.js for your application locally.

But, if for some reason you are installing express globally, make sure the directory you are in is the directory where Node is installed. On my Windows 10, package.json is located at

C:\Program Files\nodejs\node_modules\npm

Open command prompt as administrator and change your directory to the location where your package.json is located.

Then issue the install command.

Adding calculated column(s) to a dataframe in pandas

The exact code will vary for each of the columns you want to do, but it's likely you'll want to use the map and apply functions. In some cases you can just compute using the existing columns directly, since the columns are Pandas Series objects, which also work as Numpy arrays, which automatically work element-wise for usual mathematical operations.

>>> d
    A   B  C
0  11  13  5
1   6   7  4
2   8   3  6
3   4   8  7
4   0   1  7
>>> (d.A + d.B) / d.C
0    4.800000
1    3.250000
2    1.833333
3    1.714286
4    0.142857
>>> d.A > d.C
0     True
1     True
2     True
3    False
4    False

If you need to use operations like max and min within a row, you can use apply with axis=1 to apply any function you like to each row. Here's an example that computes min(A, B)-C, which seems to be like your "lower wick":

>>> d.apply(lambda row: min([row['A'], row['B']])-row['C'], axis=1)
0    6
1    2
2   -3
3   -3
4   -7

Hopefully that gives you some idea of how to proceed.

Edit: to compare rows against neighboring rows, the simplest approach is to slice the columns you want to compare, leaving off the beginning/end, and then compare the resulting slices. For instance, this will tell you for which rows the element in column A is less than the next row's element in column C:

d['A'][:-1] < d['C'][1:]

and this does it the other way, telling you which rows have A less than the preceding row's C:

d['A'][1:] < d['C'][:-1]

Doing ['A"][:-1] slices off the last element of column A, and doing ['C'][1:] slices off the first element of column C, so when you line these two up and compare them, you're comparing each element in A with the C from the following row.

How to run function of parent window when child window closes?

The answers as they are require you to add code to the spawned window. That is unnecessary coupling.

// In parent window
var pop = open(url);
pop.onunload = function() {
  // Run your code, the popup window is unloading
  // Beware though, this will also fire if the user navigates to a different
  // page within thepopup. If you need to support that, you will have to play around
  // with pop.closed and setTimeouts
}

Merge / convert multiple PDF files into one PDF

Although it's not a command line solution, it may help macos users:

  1. Select your PDF files
  2. Right-click on your highlighted files
  3. Select Quick actions > Create PDF

JAVA Unsupported major.minor version 51.0

This is because of a higher JDK during compile time and lower JDK during runtime. So you just need to update your JDK version, possible to JDK 7

You may also check Unsupported major.minor version 51.0

How to make a <div> or <a href="#"> to align center

I don't know why but for me text-align:center; only works with:

text-align: grid;

OR

display: inline-grid;

I checked and no one style is overriding.

My structure:

<ul>
    <li>
        <a>ElementToCenter</a>
    </li>
</ul>

Passing arguments forward to another javascript function

The explanation that none of the other answers supplies is that the original arguments are still available, but not in the original position in the arguments object.

The arguments object contains one element for each actual parameter provided to the function. When you call a you supply three arguments: the numbers 1, 2, and, 3. So, arguments contains [1, 2, 3].

function a(args){
    console.log(arguments) // [1, 2, 3]
    b(arguments);
}

When you call b, however, you pass exactly one argument: a's arguments object. So arguments contains [[1, 2, 3]] (i.e. one element, which is a's arguments object, which has properties containing the original arguments to a).

function b(args){
    // arguments are lost?
    console.log(arguments) // [[1, 2, 3]]
}

a(1,2,3);

As @Nick demonstrated, you can use apply to provide a set arguments object in the call.

The following achieves the same result:

function a(args){
    b(arguments[0], arguments[1], arguments[2]); // three arguments
}

But apply is the correct solution in the general case.

How to copy a row and insert in same table with a autoincrement field in MySQL?

This helped and it supports a BLOB/TEXT columns.

CREATE TEMPORARY TABLE temp_table
AS
SELECT * FROM source_table WHERE id=2;
UPDATE temp_table SET id=NULL WHERE id=2;
INSERT INTO source_table SELECT * FROM temp_table;
DROP TEMPORARY TABLE temp_table;
USE source_table;

Client to send SOAP request and receive response

I normally use another way to do the same

using System.Xml;
using System.Net;
using System.IO;

public static void CallWebService()
{
    var _url = "http://xxxxxxxxx/Service1.asmx";
    var _action = "http://xxxxxxxx/Service1.asmx?op=HelloWorld";

    XmlDocument soapEnvelopeXml = CreateSoapEnvelope();
    HttpWebRequest webRequest = CreateWebRequest(_url, _action);
    InsertSoapEnvelopeIntoWebRequest(soapEnvelopeXml, webRequest);

    // begin async call to web request.
    IAsyncResult asyncResult = webRequest.BeginGetResponse(null, null);

    // suspend this thread until call is complete. You might want to
    // do something usefull here like update your UI.
    asyncResult.AsyncWaitHandle.WaitOne();

    // get the response from the completed web request.
    string soapResult;
    using (WebResponse webResponse = webRequest.EndGetResponse(asyncResult))
    {
        using (StreamReader rd = new StreamReader(webResponse.GetResponseStream()))
        {
            soapResult = rd.ReadToEnd();
        }
        Console.Write(soapResult);        
    }
}

private static HttpWebRequest CreateWebRequest(string url, string action)
{
    HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
    webRequest.Headers.Add("SOAPAction", action);
    webRequest.ContentType = "text/xml;charset=\"utf-8\"";
    webRequest.Accept = "text/xml";
    webRequest.Method = "POST";
    return webRequest;
}

private static XmlDocument CreateSoapEnvelope()
{
    XmlDocument soapEnvelopeDocument = new XmlDocument();
    soapEnvelopeDocument.LoadXml(
    @"<SOAP-ENV:Envelope xmlns:SOAP-ENV=""http://schemas.xmlsoap.org/soap/envelope/"" 
               xmlns:xsi=""http://www.w3.org/1999/XMLSchema-instance"" 
               xmlns:xsd=""http://www.w3.org/1999/XMLSchema"">
        <SOAP-ENV:Body>
            <HelloWorld xmlns=""http://tempuri.org/"" 
                SOAP-ENV:encodingStyle=""http://schemas.xmlsoap.org/soap/encoding/"">
                <int1 xsi:type=""xsd:integer"">12</int1>
                <int2 xsi:type=""xsd:integer"">32</int2>
            </HelloWorld>
        </SOAP-ENV:Body>
    </SOAP-ENV:Envelope>");
    return soapEnvelopeDocument;
}

private static void InsertSoapEnvelopeIntoWebRequest(XmlDocument soapEnvelopeXml, HttpWebRequest webRequest)
{
    using (Stream stream = webRequest.GetRequestStream())
    {
        soapEnvelopeXml.Save(stream);
    }
}

Android Imagebutton change Image OnClick

It is very simple

public void onClick(View v) {

        imgButton.setImageResource(R.drawable.ic_launcher);

    }

Using set Background image resource will chanage the background of the button

JAXB :Need Namespace Prefix to all the elements

marshaller.setProperty only works on the JAX-B marshaller from Sun. The question was regarding the JAX-B marshaller from SpringSource, which does not support setProperty.

How do I make an auto increment integer field in Django?

You can use default primary key (id) which auto increaments.

Note: When you use first design i.e. use default field (id) as a primary key, initialize object by mentioning column names. e.g.

class User(models.Model):
    user_name = models.CharField(max_length = 100)

then initialize,

user = User(user_name="XYZ")

if you initialize in following way,

user = User("XYZ")

then python will try to set id = "XYZ" which will give you error on data type.

Saving lists to txt file

Assuming your Generic List is of type String:

TextWriter tw = new StreamWriter("SavedList.txt");

foreach (String s in Lists.verbList)
   tw.WriteLine(s);

tw.Close();

Alternatively, with the using keyword:

using(TextWriter tw = new StreamWriter("SavedList.txt"))
{
   foreach (String s in Lists.verbList)
      tw.WriteLine(s);
}

How can I use grep to show just filenames on Linux?

From the grep(1) man page:

  -l, --files-with-matches
          Suppress  normal  output;  instead  print the name of each input
          file from which output would normally have  been  printed.   The
          scanning  will  stop  on  the  first match.  (-l is specified by
          POSIX.)

Using the && operator in an if statement

So to make your expression work, changing && for -a will do the trick.

It is correct like this:

 if [ -f $VAR1 ] && [ -f $VAR2 ] && [ -f $VAR3 ]
 then  ....

or like

 if [[ -f $VAR1 && -f $VAR2 && -f $VAR3 ]]
 then  ....

or even

 if [ -f $VAR1 -a -f $VAR2 -a -f $VAR3 ]
 then  ....

You can find further details in this question bash : Multiple Unary operators in if statement and some references given there like What is the difference between test, [ and [[ ?.

Detach (move) subdirectory into separate Git repository

Paul's answer creates a new repository containing /ABC, but does not remove /ABC from within /XYZ. The following command will remove /ABC from within /XYZ:

git filter-branch --tree-filter "rm -rf ABC" --prune-empty HEAD

Of course, test it in a 'clone --no-hardlinks' repository first, and follow it with the reset, gc and prune commands Paul lists.

How to check for file existence

# file? will only return true for files
File.file?(filename)

and

# Will also return true for directories - watch out!
File.exist?(filename)

PHP, pass array through POST

Why are you sending it through a post if you already have it on the server (PHP) side?

Why not just save the array to s $_SESSION variable so you can use it when the form gets submitted, that might make it more "secure" since then the client cannot change the variables by editing the source.

It all depends on what you really want to do.

How to modify a global variable within a function in bash?

This needs bash 4.1 if you use {fd} or local -n.

The rest should work in bash 3.x I hope. I am not completely sure due to printf %q - this might be a bash 4 feature.

Summary

Your example can be modified as follows to archive the desired effect:

# Add following 4 lines:
_passback() { while [ 1 -lt $# ]; do printf '%q=%q;' "$1" "${!1}"; shift; done; return $1; }
passback() { _passback "$@" "$?"; }
_capture() { { out="$("${@:2}" 3<&-; "$2_" >&3)"; ret=$?; printf "%q=%q;" "$1" "$out"; } 3>&1; echo "(exit $ret)"; }
capture() { eval "$(_capture "$@")"; }

e=2

# Add following line, called "Annotation"
function test1_() { passback e; }
function test1() {
  e=4
  echo "hello"
}

# Change following line to:
capture ret test1 

echo "$ret"
echo "$e"

prints as desired:

hello
4

Note that this solution:

  • Works for e=1000, too.
  • Preserves $? if you need $?

The only bad sideffects are:

  • It needs a modern bash.
  • It forks quite more often.
  • It needs the annotation (named after your function, with an added _)
  • It sacrifices file descriptor 3.
    • You can change it to another FD if you need that.
      • In _capture just replace all occurances of 3 with another (higher) number.

The following (which is quite long, sorry for that) hopefully explains, how to adpot this recipe to other scripts, too.

The problem

d() { let x++; date +%Y%m%d-%H%M%S; }

x=0
d1=$(d)
d2=$(d)
d3=$(d)
d4=$(d)
echo $x $d1 $d2 $d3 $d4

outputs

0 20171129-123521 20171129-123521 20171129-123521 20171129-123521

while the wanted output is

4 20171129-123521 20171129-123521 20171129-123521 20171129-123521

The cause of the problem

Shell variables (or generally speaking, the environment) is passed from parental processes to child processes, but not vice versa.

If you do output capturing, this usually is run in a subshell, so passing back variables is difficult.

Some even tell you, that it is impossible to fix. This is wrong, but it is a long known difficult to solve problem.

There are several ways on how to solve it best, this depends on your needs.

Here is a step by step guide on how to do it.

Passing back variables into the parental shell

There is a way to pass back variables to a parental shell. However this is a dangerous path, because this uses eval. If done improperly, you risk many evil things. But if done properly, this is perfectly safe, provided that there is no bug in bash.

_passback() { while [ 0 -lt $# ]; do printf '%q=%q;' "$1" "${!1}"; shift; done; }

d() { let x++; d=$(date +%Y%m%d-%H%M%S); _passback x d; }

x=0
eval `d`
d1=$d
eval `d`
d2=$d
eval `d`
d3=$d
eval `d`
d4=$d
echo $x $d1 $d2 $d3 $d4

prints

4 20171129-124945 20171129-124945 20171129-124945 20171129-124945

Note that this works for dangerous things, too:

danger() { danger="$*"; passback danger; }
eval `danger '; /bin/echo *'`
echo "$danger"

prints

; /bin/echo *

This is due to printf '%q', which quotes everything such, that you can re-use it in a shell context safely.

But this is a pain in the a..

This does not only look ugly, it also is much to type, so it is error prone. Just one single mistake and you are doomed, right?

Well, we are at shell level, so you can improve it. Just think about an interface you want to see, and then you can implement it.

Augment, how the shell processes things

Let's go a step back and think about some API which allows us to easily express, what we want to do.

Well, what do we want do do with the d() function?

We want to capture the output into a variable. OK, then let's implement an API for exactly this:

# This needs a modern bash 4.3 (see "help declare" if "-n" is present,
# we get rid of it below anyway).
: capture VARIABLE command args..
capture()
{
local -n output="$1"
shift
output="$("$@")"
}

Now, instead of writing

d1=$(d)

we can write

capture d1 d

Well, this looks like we haven't changed much, as, again, the variables are not passed back from d into the parent shell, and we need to type a bit more.

However now we can throw the full power of the shell at it, as it is nicely wrapped in a function.

Think about an easy to reuse interface

A second thing is, that we want to be DRY (Don't Repeat Yourself). So we definitively do not want to type something like

x=0
capture1 x d1 d
capture1 x d2 d
capture1 x d3 d
capture1 x d4 d
echo $x $d1 $d2 $d3 $d4

The x here is not only redundant, it's error prone to always repeate in the correct context. What if you use it 1000 times in a script and then add a variable? You definitively do not want to alter all the 1000 locations where a call to d is involved.

So leave the x away, so we can write:

_passback() { while [ 0 -lt $# ]; do printf '%q=%q;' "$1" "${!1}"; shift; done; }

d() { let x++; output=$(date +%Y%m%d-%H%M%S); _passback output x; }

xcapture() { local -n output="$1"; eval "$("${@:2}")"; }

x=0
xcapture d1 d
xcapture d2 d
xcapture d3 d
xcapture d4 d
echo $x $d1 $d2 $d3 $d4

outputs

4 20171129-132414 20171129-132414 20171129-132414 20171129-132414

This already looks very good. (But there still is the local -n which does not work in oder common bash 3.x)

Avoid changing d()

The last solution has some big flaws:

  • d() needs to be altered
  • It needs to use some internal details of xcapture to pass the output.
    • Note that this shadows (burns) one variable named output, so we can never pass this one back.
  • It needs to cooperate with _passback

Can we get rid of this, too?

Of course, we can! We are in a shell, so there is everything we need to get this done.

If you look a bit closer to the call to eval you can see, that we have 100% control at this location. "Inside" the eval we are in a subshell, so we can do everything we want without fear of doing something bad to the parental shell.

Yeah, nice, so let's add another wrapper, now directly inside the eval:

_passback() { while [ 0 -lt $# ]; do printf '%q=%q;' "$1" "${!1}"; shift; done; }
# !DO NOT USE!
_xcapture() { "${@:2}" > >(printf "%q=%q;" "$1" "$(cat)"); _passback x; }  # !DO NOT USE!
# !DO NOT USE!
xcapture() { eval "$(_xcapture "$@")"; }

d() { let x++; date +%Y%m%d-%H%M%S; }

x=0
xcapture d1 d
xcapture d2 d
xcapture d3 d
xcapture d4 d
echo $x $d1 $d2 $d3 $d4

prints

4 20171129-132414 20171129-132414 20171129-132414 20171129-132414                                                    

However, this, again, has some major drawback:

  • The !DO NOT USE! markers are there, because there is a very bad race condition in this, which you cannot see easily:
    • The >(printf ..) is a background job. So it might still execute while the _passback x is running.
    • You can see this yourself if you add a sleep 1; before printf or _passback. _xcapture a d; echo then outputs x or a first, respectively.
  • The _passback x should not be part of _xcapture, because this makes it difficult to reuse that recipe.
  • Also we have some unneded fork here (the $(cat)), but as this solution is !DO NOT USE! I took the shortest route.

However, this shows, that we can do it, without modification to d() (and without local -n)!

Please note that we not neccessarily need _xcapture at all, as we could have written everyting right in the eval.

However doing this usually isn't very readable. And if you come back to your script in a few years, you probably want to be able to read it again without much trouble.

Fix the race

Now let's fix the race condition.

The trick could be to wait until printf has closed it's STDOUT, and then output x.

There are many ways to archive this:

  • You cannot use shell pipes, because pipes run in different processes.
  • One can use temporary files,
  • or something like a lock file or a fifo. This allows to wait for the lock or fifo,
  • or different channels, to output the information, and then assemble the output in some correct sequence.

Following the last path could look like (note that it does the printf last because this works better here):

_passback() { while [ 0 -lt $# ]; do printf '%q=%q;' "$1" "${!1}"; shift; done; }

_xcapture() { { printf "%q=%q;" "$1" "$("${@:2}" 3<&-; _passback x >&3)"; } 3>&1; }

xcapture() { eval "$(_xcapture "$@")"; }

d() { let x++; date +%Y%m%d-%H%M%S; }

x=0
xcapture d1 d
xcapture d2 d
xcapture d3 d
xcapture d4 d
echo $x $d1 $d2 $d3 $d4

outputs

4 20171129-144845 20171129-144845 20171129-144845 20171129-144845

Why is this correct?

  • _passback x directly talks to STDOUT.
  • However, as STDOUT needs to be captured in the inner command, we first "save" it into FD3 (you can use others, of course) with '3>&1' and then reuse it with >&3.
  • The $("${@:2}" 3<&-; _passback x >&3) finishes after the _passback, when the subshell closes STDOUT.
  • So the printf cannot happen before the _passback, regardless how long _passback takes.
  • Note that the printf command is not executed before the complete commandline is assembled, so we cannot see artefacts from printf, independently how printf is implemented.

Hence first _passback executes, then the printf.

This resolves the race, sacrificing one fixed file descriptor 3. You can, of course, choose another file descriptor in the case, that FD3 is not free in your shellscript.

Please also note the 3<&- which protects FD3 to be passed to the function.

Make it more generic

_capture contains parts, which belong to d(), which is bad, from a reusability perspective. How to solve this?

Well, do it the desparate way by introducing one more thing, an additional function, which must return the right things, which is named after the original function with _ attached.

This function is called after the real function, and can augment things. This way, this can be read as some annotation, so it is very readable:

_passback() { while [ 0 -lt $# ]; do printf '%q=%q;' "$1" "${!1}"; shift; done; }
_capture() { { printf "%q=%q;" "$1" "$("${@:2}" 3<&-; "$2_" >&3)"; } 3>&1; }
capture() { eval "$(_capture "$@")"; }

d_() { _passback x; }
d() { let x++; date +%Y%m%d-%H%M%S; }

x=0
capture d1 d
capture d2 d
capture d3 d
capture d4 d
echo $x $d1 $d2 $d3 $d4

still prints

4 20171129-151954 20171129-151954 20171129-151954 20171129-151954

Allow access to the return-code

There is only on bit missing:

v=$(fn) sets $? to what fn returned. So you probably want this, too. It needs some bigger tweaking, though:

# This is all the interface you need.
# Remember, that this burns FD=3!
_passback() { while [ 1 -lt $# ]; do printf '%q=%q;' "$1" "${!1}"; shift; done; return $1; }
passback() { _passback "$@" "$?"; }
_capture() { { out="$("${@:2}" 3<&-; "$2_" >&3)"; ret=$?; printf "%q=%q;" "$1" "$out"; } 3>&1; echo "(exit $ret)"; }
capture() { eval "$(_capture "$@")"; }

# Here is your function, annotated with which sideffects it has.
fails_() { passback x y; }
fails() { x=$1; y=69; echo FAIL; return 23; }

# And now the code which uses it all
x=0
y=0
capture wtf fails 42
echo $? $x $y $wtf

prints

23 42 69 FAIL

There is still a lot room for improvement

  • _passback() can be elmininated with passback() { set -- "$@" "$?"; while [ 1 -lt $# ]; do printf '%q=%q;' "$1" "${!1}"; shift; done; return $1; }
  • _capture() can be eliminated with capture() { eval "$({ out="$("${@:2}" 3<&-; "$2_" >&3)"; ret=$?; printf "%q=%q;" "$1" "$out"; } 3>&1; echo "(exit $ret)")"; }

  • The solution pollutes a file descriptor (here 3) by using it internally. You need to keep that in mind if you happen to pass FDs.
    Note thatbash 4.1 and above has {fd} to use some unused FD.
    (Perhaps I will add a solution here when I come around.)
    Note that this is why I use to put it in separate functions like _capture, because stuffing this all into one line is possible, but makes it increasingly harder to read and understand

  • Perhaps you want to capture STDERR of the called function, too. Or you want to even pass in and out more than one filedescriptor from and to variables.
    I have no solution yet, however here is a way to catch more than one FD, so we can probably pass back the variables this way, too.

Also do not forget:

This must call a shell function, not an external command.

There is no easy way to pass environment variables out of external commands. (With LD_PRELOAD= it should be possible, though!) But this then is something completely different.

Last words

This is not the only possible solution. It is one example to a solution.

As always you have many ways to express things in the shell. So feel free to improve and find something better.

The solution presented here is quite far from being perfect:

  • It was nearly not testet at all, so please forgive typos.
  • There is a lot of room for improvement, see above.
  • It uses many features from modern bash, so probably is hard to port to other shells.
  • And there might be some quirks I haven't thought about.

However I think it is quite easy to use:

  • Add just 4 lines of "library".
  • Add just 1 line of "annotation" for your shell function.
  • Sacrifices just one file descriptor temporarily.
  • And each step should be easy to understand even years later.

Could not load file or assembly CrystalDecisions.ReportAppServer.ClientDoc

It turns out the answer was ridiculously simple, but mystifying as to why it was necessary.

In the IIS Manager on the server, I set the application pool for my web application to not allow 32-bit assemblies.

It seems it assumes, on a 64-bit system, that you must want the 32 bit assembly. Bizarre.

Find rows that have the same value on a column in MySQL

This works best

Screenshot enter image description here

SELECT RollId, count(*) AS c 
    FROM `tblstudents` 
    GROUP BY RollId 
    HAVING c > 1 
    ORDER BY c DESC

Retrieving the output of subprocess.call()

For python 3.5+ it is recommended that you use the run function from the subprocess module. This returns a CompletedProcess object, from which you can easily obtain the output as well as return code.

from subprocess import PIPE, run

command = ['echo', 'hello']
result = run(command, stdout=PIPE, stderr=PIPE, universal_newlines=True)
print(result.returncode, result.stdout, result.stderr)

CSS3 Transition - Fade out effect

Since display is not one of the animatable CSS properties. One display:none fadeOut animation replacement with pure CSS3 animations, just set width:0 and height:0 at last frame, and use animation-fill-mode: forwards to keep width:0 and height:0 properties.

@-webkit-keyframes fadeOut {
    0% { opacity: 1;}
    99% { opacity: 0.01;width: 100%; height: 100%;}
    100% { opacity: 0;width: 0; height: 0;}
}  
@keyframes fadeOut {
    0% { opacity: 1;}
    99% { opacity: 0.01;width: 100%; height: 100%;}
    100% { opacity: 0;width: 0; height: 0;}
}

.display-none.on{
    display: block;
    -webkit-animation: fadeOut 1s;
    animation: fadeOut 1s;
    animation-fill-mode: forwards;
}

Pythonic way to return list of every nth item in a larger list

  1. source_list[::10] is the most obvious, but this doesn't work for any iterable and is not memory efficient for large lists.
  2. itertools.islice(source_sequence, 0, None, 10) works for any iterable and is memory-efficient, but probably is not the fastest solution for large list and big step.
  3. (source_list[i] for i in xrange(0, len(source_list), 10))

PHP __get and __set magic methods

From the PHP manual:

  • __set() is run when writing data to inaccessible properties.
  • __get() is utilized for reading data from inaccessible properties.

This is only called on reading/writing inaccessible properties. Your property however is public, which means it is accessible. Changing the access modifier to protected solves the issue.

java.lang.IllegalAccessError: tried to access method

In my case the problem was that a method was defined in some Interface A as default, while its sub-class overrode it as private. Then when the method was called, the java Runtime realized it was calling a private method.

I am still puzzled as to why the compiler didn't complain about the private override..

public interface A {
     default void doStuff() {
         // doing stuff
     }
}

public class B {
     private void doStuff() {
         // do other stuff instead
     }
}

public static final main(String... args) {
    A someB = new B();
    someB.doStuff();
}

How to specify maven's distributionManagement organisation wide?

Regarding the answer from Michael Wyraz, where you use alt*DeploymentRepository in your settings.xml or command on the line, be careful if you are using version 3.0.0-M1 of the maven-deploy-plugin (which is the latest version at the time of writing), there is a bug in this version that could cause a server authentication issue.

A workaround is as follows. In the value:

releases::default::https://YOUR_NEXUS_URL/releases

you need to remove the default section, making it:

releases::https://YOUR_NEXUS_URL/releases

The prior version 2.8.2 does not have this bug.

Android Service needs to run always (Never pause or stop)

In order to start a service in its own process, you must specify the following in the xml declaration.

<service
  android:name="WordService"
  android:process=":my_process" 
  android:icon="@drawable/icon"
  android:label="@string/service_name"
  >
</service> 

Here you can find a good tutorial that was really useful to me

http://www.vogella.com/articles/AndroidServices/article.html

Hope this helps

plain count up timer in javascript

Extending from @Chandu, with some UI added:

<html>
<head>
<script   src="https://code.jquery.com/jquery-3.2.1.min.js"   integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4="   crossorigin="anonymous"></script>
</head>
<style>
button {
background: steelblue; 
border-radius: 4px; 
height: 40px; 
width: 100px; 
color: white; 
font-size: 20px; 
cursor: pointer; 
border: none; 
}
button:focus {
outline: 0; 
}
#minutes, #seconds {
font-size: 40px; 
}
.bigger {
font-size: 40px; 
}
.button {
  box-shadow: 0 9px #999;
}

.button:hover {background-color: hotpink}

.button:active {
  background-color: hotpink;
  box-shadow: 0 5px #666;
  transform: translateY(4px);
}
</style>
<body align='center'>
<button onclick='set_timer()' class='button'>START</button>
<button onclick='stop_timer()' class='button'>STOP</button><br><br>
<label id="minutes">00</label><span class='bigger'>:</span><label id="seconds">00</label>
</body>
</html>
<script>

function pad(val) {
  valString = val + "";
  if(valString.length < 2) {
     return "0" + valString;
     } else {
     return valString;
     }
}

totalSeconds = 0;
function setTime(minutesLabel, secondsLabel) {
    totalSeconds++;
    secondsLabel.innerHTML = pad(totalSeconds%60);
    minutesLabel.innerHTML = pad(parseInt(totalSeconds/60));
    }

function set_timer() {
    minutesLabel = document.getElementById("minutes");
    secondsLabel = document.getElementById("seconds");
    my_int = setInterval(function() { setTime(minutesLabel, secondsLabel)}, 1000);
}

function stop_timer() {
  clearInterval(my_int);
}


</script>

Looks as follows:

enter image description here

Could not reserve enough space for object heap to start JVM

According to this post this error message means:

Heap size is larger than your computer's physical memory.

Edit: Heap is not the only memory that is reserved, I suppose. At least there are other JVM settings like PermGenSpace that ask for the memory. With heap size 128M and a PermGenSpace of 64M you already fill the space available.

Why not downsize other memory settings to free up space for the heap?

PHP Session data not being saved

Well, we can eliminate code error because I tested the code on my own server (PHP 5).

Here's what to check for:

  1. Are you calling session_unset() or session_destroy() anywhere? These functions will delete the session data immediately. If I put these at the end of my script, it begins behaving exactly like you describe.

  2. Does it act the same in all browsers? If it works on one browser and not another, you may have a configuration problem on the nonfunctioning browser (i.e. you turned off cookies and forgot to turn them on, or are blocking cookies by mistake).

  3. Is the session folder writable? You can't test this with is_writable(), so you'll need to go to the folder (from phpinfo() it looks like /var/php_sessions) and make sure sessions are actually getting created.

How to print a string in C++

While using string, the best possible way to print your message is:

#include <iostream>
#include <string>
using namespace std;

int main(){
  string newInput;
  getline(cin, newInput);
  cout<<newInput;
  return 0;
}


this can simply do the work instead of doing the method you adopted.

Node.js create folder or use existing

I propose a solution without modules (accumulate modules is never recommended for maintainability especially for small functions that can be written in a few lines...) :

LAST UPDATE :

In v10.12.0, NodeJS impletement recursive options :

// Create recursive folder
fs.mkdir('my/new/folder/create', { recursive: true }, (err) => { if (err) throw err; });

UPDATE :

// Get modules node
const fs   = require('fs');
const path = require('path');

// Create 
function mkdirpath(dirPath)
{
    if(!fs.accessSync(dirPath, fs.constants.R_OK | fs.constants.W_OK))
    {
        try
        {
            fs.mkdirSync(dirPath);
        }
        catch(e)
        {
            mkdirpath(path.dirname(dirPath));
            mkdirpath(dirPath);
        }
    }
}

// Create folder path
mkdirpath('my/new/folder/create');

Finding square root without using sqrt function?

Why not try to use the Babylonian method for finding a square root.

Here is my code for it:

double sqrt(double number)
{
    double error = 0.00001; //define the precision of your result
    double s = number;

    while ((s - number / s) > error) //loop until precision satisfied 
    {
        s = (s + number / s) / 2;
    }
    return s;
}

Good luck!

How to see the proxy settings on windows?

It's possible to view proxy settings in Google Chrome:

chrome://net-internals/#proxy

Enter this in the address bar of Chrome.

Returning Arrays in Java

It is returning the array, but all returning something (including an Array) does is just what it sounds like: returns the value. In your case, you are getting the value of numbers(), which happens to be an array (it could be anything and you would still have this issue), and just letting it sit there.

When a function returns anything, it is essentially replacing the line in which it is called (in your case: numbers();) with the return value. So, what your main method is really executing is essentially the following:

public static void main(String[] args) {
    {1,2,3};
}

Which, of course, will appear to do nothing. If you wanted to do something with the return value, you could do something like this:

public static void main(String[] args){
    int[] result = numbers();
    for (int i=0; i<result.length; i++) {
        System.out.print(result[i]+" ");
    }
}

How to force div to appear below not next to another?

what u can also do i place an extra "dummy" div before your last div.

Make it 1 px heigh and the width as much needed to cover the container div/body

This will make the last div appear under it, starting from the left.

Tensorflow import error: No module named 'tensorflow'

The reason why Python base environment is unable to import Tensorflow is that Anaconda does not store the tensorflow package in the base environment.

create a new separate environment in Anaconda dedicated to TensorFlow as follows:

conda create -n newenvt anaconda python=python_version

replace python_version by your python version

activate the new environment as follows:

activate newenvt

Then install tensorflow into the new environment (newenvt) as follows:

conda install tensorflow

Now you can check it by issuing the following python code and it will work fine.

import tensorflow

Convert datetime to Unix timestamp and convert it back in python

For working with UTC timezones:

time_stamp = calendar.timegm(dt.timetuple())

datetime.utcfromtimestamp(time_stamp)

Automatically enter SSH password with script

This is how I login to my servers.

ssp <server_ip>
  • alias ssp='/home/myuser/Documents/ssh_script.sh'
  • cat /home/myuser/Documents/ssh_script.sh

#!/bin/bash

sshpass -p mypassword ssh root@$1

And therefore...

ssp server_ip

java.net.ConnectException: failed to connect to /192.168.253.3 (port 2468): connect failed: ECONNREFUSED (Connection refused)

My problem was solved after turning Off Windows Firewall Defender in public network as I was connected with that network.

DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss") is returning AM time instead of PM time?

With C#6.0 you also have a new way of formatting date when using string interpolation e.g.

$"{DateTime.Now:yyyy-MM-dd HH:mm:ss}"

Can't say its any better, but it is slightly cleaner if including the formatted DateTime in a longer string.

More about string interpolation.

How to run a Python script in the background even after I logout SSH?

Try this:

nohup python -u <your file name>.py >> <your log file>.log &

You can run above command in screen and come out of screen.

Now you can tail logs of your python script by: tail -f <your log file>.log

To kill you script, you can use ps -aux and kill commands.

Bootstrap 3: Using img-circle, how to get circle from non-square image?

I use these two methods depending on the usage. FIDDLE

<div class="img-div">
<img src="http://placekitten.com/g/400/200" />
</div>
<div class="circle-image"></div>

div.img-div{
    height:200px;
    width:200px;
    overflow:hidden;
    border-radius:50%;
}

.img-div img{
    -webkit-transform:translate(-50%);
    margin-left:100px;
}

.circle-image{
    width:200px;
    height:200px;
    border-radius:50%;
    background-image:url("http://placekitten.com/g/200/400");
    display:block;
    background-position-y:25% 
}

Iterate all files in a directory using a 'for' loop

I would use vbscript (Windows Scripting Host), because in batch I'm sure you cannot tell that a name is a file or a directory.

In vbs, it can be something like this:

Dim fileSystemObject
Set fileSystemObject = CreateObject("Scripting.FileSystemObject")

Dim mainFolder
Set mainFolder = fileSystemObject.GetFolder(myFolder)

Dim files
Set files = mainFolder.Files

For Each file in files
...
Next

Dim subFolders
Set subFolders = mainFolder.SubFolders

For Each folder in subFolders
...
Next

Check FileSystemObject on MSDN.

Efficient way of having a function only execute once in a loop

I'm not sure that I understood your problem, but I think you can divide loop. On the part of the function and the part without it and save the two loops.

How to receive JSON as an MVC 5 action method parameter

You are sending a array of string

var usersRoles = [];
jQuery("#dualSelectRoles2 option").each(function () {
    usersRoles.push(jQuery(this).val());
});   

So change model type accordingly

 public ActionResult AddUser(List<string> model)
 {
 }

Close virtual keyboard on button press

InputMethodManager inputManager = (InputMethodManager)
                                  getSystemService(Context.INPUT_METHOD_SERVICE); 

inputManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(),
                                     InputMethodManager.HIDE_NOT_ALWAYS);

I put this right after the onClick(View v) event.

You need to import android.view.inputmethod.InputMethodManager;

The keyboard hides when you click the button.

How to get Current Timestamp from Carbon in Laravel 5

Laravel 5.2 <= 5.5

    use Carbon\Carbon; // You need to import Carbon
    $current_time = Carbon::now()->toDayDateTimeString(); // Wed, May 17, 2017 10:42 PM
    $current_timestamp = Carbon::now()->timestamp; // Unix timestamp 1495062127

In addition, this is how to change datetime format for given date & time, in blade:

{{\Carbon\Carbon::parse($dateTime)->format('D, d M \'y, H:i')}}

Laravel 5.6 <

$current_timestamp = now()->timestamp;

Bootstrap 3 truncate long text inside rows of a table in a responsive way

I did it this way (you need to add a class text to <td> and put the text between a <span>:

HTML

<td class="text"><span>looooooong teeeeeeeeext</span></td>

SASS

.table td.text {
    max-width: 177px;
    span {
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        display: inline-block;
        max-width: 100%;
    }
}

CSS equivalent

.table td.text {
    max-width: 177px;
}
.table td.text span {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    display: inline-block;
    max-width: 100%;
}

And it will still be mobile responsive (forget it with layout=fixed) and will keep the original behaviour.

PS: Of course 177px is a custom size (put whatever you need).

FutureWarning: elementwise comparison failed; returning scalar, but in the future will perform elementwise comparison

I had this code which was causing the error:

for t in dfObj['time']:
  if type(t) == str:
    the_date = dateutil.parser.parse(t)
    loc_dt_int = int(the_date.timestamp())
    dfObj.loc[t == dfObj.time, 'time'] = loc_dt_int

I changed it to this:

for t in dfObj['time']:
  try:
    the_date = dateutil.parser.parse(t)
    loc_dt_int = int(the_date.timestamp())
    dfObj.loc[t == dfObj.time, 'time'] = loc_dt_int
  except Exception as e:
    print(e)
    continue

to avoid the comparison, which is throwing the warning - as stated above. I only had to avoid the exception because of dfObj.loc in the for loop, maybe there is a way to tell it not to check the rows it has already changed.

Can linux cat command be used for writing text to file?

Here's another way -

cat > outfile.txt
>Enter text
>to save press ctrl-d

How can I correctly format currency using jquery?

I used to use the jquery format currency plugin, but it has been very buggy recently. I only need formatting for USD/CAD, so I wrote my own automatic formatting.

$(".currencyMask").change(function () {
            if (!$.isNumeric($(this).val()))
                $(this).val('0').trigger('change');

            $(this).val(parseFloat($(this).val(), 10).toFixed(2).replace(/(\d)(?=(\d{3})+\.)/g, "$1,").toString());
        });

Simply set the class of whatever input should be formatted as currency <input type="text" class="currencyMask" /> and it will format it perfectly in any browser.

How to print out the method name and line number and conditionally disable NSLog?

To complement the answers above, it can be quite useful to use a replacement for NSLog in certain situations, especially when debugging. For example, getting rid of all the date and process name/id information on each line can make output more readable and faster to boot.

The following link provides quite a bit of useful ammo for making simple logging much nicer.

http://cocoaheads.byu.edu/wiki/a-different-nslog

jQuery get text as number

If anyone came here trying to do this with a decimal like me:

myFloat = parseFloat(myString);

If you just need an Int, that's well covered in the other answers.

Float vs Decimal in ActiveRecord

In Rails 3.2.18, :decimal turns into :integer when using SQLServer, but it works fine in SQLite. Switching to :float solved this issue for us.

The lesson learned is "always use homogeneous development and deployment databases!"

How to get File Created Date and Modified Date

You can use this code to see the last modified date of a file.

DateTime dt = File.GetLastWriteTime(path);

And this code to see the creation time.

DateTime fileCreatedDate = File.GetCreationTime(@"C:\Example\MyTest.txt");

How do I align a number like this in C?

Looking at the edited question, you need to find the number of digits in the largest number to be presented, and then generate the printf() format using sprintf(), or using %*d with the number of digits being passed as an int for the * and then the value. Once you've got the biggest number (and you have to determine that in advance), you can determine the number of digits with an 'integer logarithm' algorithm (how many times can you divide by 10 before you get to zero), or by using snprintf() with the buffer length of zero, the format %d and null for the string; the return value tells you how many characters would have been formatted.

If you don't know and cannot determine the maximum number ahead of its appearance, you are snookered - there is nothing you can do.

Why is it bad style to `rescue Exception => e` in Ruby?

The real rule is: Don't throw away exceptions. The objectivity of the author of your quote is questionable, as evidenced by the fact that it ends with

or I will stab you

Of course, be aware that signals (by default) throw exceptions, and normally long-running processes are terminated through a signal, so catching Exception and not terminating on signal exceptions will make your program very hard to stop. So don't do this:

#! /usr/bin/ruby

while true do
  begin
    line = STDIN.gets
    # heavy processing
  rescue Exception => e
    puts "caught exception #{e}! ohnoes!"
  end
end

No, really, don't do it. Don't even run that to see if it works.

However, say you have a threaded server and you want all exceptions to not:

  1. be ignored (the default)
  2. stop the server (which happens if you say thread.abort_on_exception = true).

Then this is perfectly acceptable in your connection handling thread:

begin
  # do stuff
rescue Exception => e
  myLogger.error("uncaught #{e} exception while handling connection: #{e.message}")
    myLogger.error("Stack trace: #{backtrace.map {|l| "  #{l}\n"}.join}")
end

The above works out to a variation of Ruby's default exception handler, with the advantage that it doesn't also kill your program. Rails does this in its request handler.

Signal exceptions are raised in the main thread. Background threads won't get them, so there is no point in trying to catch them there.

This is particularly useful in a production environment, where you do not want your program to simply stop whenever something goes wrong. Then you can take the stack dumps in your logs and add to your code to deal with specific exception further down the call chain and in a more graceful manner.

Note also that there is another Ruby idiom which has much the same effect:

a = do_something rescue "something else"

In this line, if do_something raises an exception, it is caught by Ruby, thrown away, and a is assigned "something else".

Generally, don't do that, except in special cases where you know you don't need to worry. One example:

debugger rescue nil

The debugger function is a rather nice way to set a breakpoint in your code, but if running outside a debugger, and Rails, it raises an exception. Now theoretically you shouldn't be leaving debug code lying around in your program (pff! nobody does that!) but you might want to keep it there for a while for some reason, but not continually run your debugger.

Note:

  1. If you've run someone else's program that catches signal exceptions and ignores them, (say the code above) then:

    • in Linux, in a shell, type pgrep ruby, or ps | grep ruby, look for your offending program's PID, and then run kill -9 <PID>.
    • in Windows, use the Task Manager (CTRL-SHIFT-ESC), go to the "processes" tab, find your process, right click it and select "End process".
  2. If you are working with someone else's program which is, for whatever reason, peppered with these ignore-exception blocks, then putting this at the top of the mainline is one possible cop-out:

    %W/INT QUIT TERM/.each { |sig| trap sig,"SYSTEM_DEFAULT" }
    

    This causes the program to respond to the normal termination signals by immediately terminating, bypassing exception handlers, with no cleanup. So it could cause data loss or similar. Be careful!

  3. If you need to do this:

    begin
      do_something
    rescue Exception => e
      critical_cleanup
      raise
    end
    

    you can actually do this:

    begin
      do_something
    ensure
      critical_cleanup
    end
    

    In the second case, critical cleanup will be called every time, whether or not an exception is thrown.

"message failed to fetch from registry" while trying to install any module

You also need to install software-properties-common for add-apt-repository to work. so it will be

sudo apt-get purge nodejs npm
sudo apt-get install -y python-software-properties python g++ make software-properties-common
sudo add-apt-repository ppa:chris-lea/node.js
sudo apt-get update
sudo apt-get install nodejs

TINYTEXT, TEXT, MEDIUMTEXT, and LONGTEXT maximum storage sizes

This is nice but doesn't answer the question:

"A VARCHAR should always be used instead of TINYTEXT." Tinytext is useful if you have wide rows - since the data is stored off the record. There is a performance overhead, but it does have a use.

Where does Oracle SQL Developer store connections?

In some versions, it stores it under

<installed path>\system\oracle.jdeveloper.db.connection.11.1.1.0.11.42.44
\IDEConnections.xml

How to make external HTTP requests with Node.js

NodeJS supports http.request as a standard module: http://nodejs.org/docs/v0.4.11/api/http.html#http.request

var http = require('http');

var options = {
  host: 'example.com',
  port: 80,
  path: '/foo.html'
};

http.get(options, function(resp){
  resp.on('data', function(chunk){
    //do something with chunk
  });
}).on("error", function(e){
  console.log("Got error: " + e.message);
});

Compile c++14-code with g++

The -std=c++14 flag is not supported on GCC 4.8. If you want to use C++14 features you need to compile with -std=c++1y. Using godbolt.org it appears that the earilest version to support -std=c++14 is GCC 4.9.0 or Clang 3.5.0

Insert default value when parameter is null

The pattern I generally use is to create the row without the columns that have default constraints, then update the columns to replace the default values with supplied values (if not null).

Assuming col1 is the primary key and col4 and col5 have a default contraint

-- create initial row with default values
insert table1 (col1, col2, col3)
    values (@col1, @col2, @col3)

-- update default values, if supplied
update table1
    set col4 = isnull(@col4, col4),
        col5 = isnull(@col5, col5)
    where col1 = @col1

If you want the actual values defaulted into the table ...

-- create initial row with default values
insert table1 (col1, col2, col3)
    values (@col1, @col2, @col3)

-- create a container to hold the values actually inserted into the table
declare @inserted table (col4 datetime, col5 varchar(50))

-- update default values, if supplied
update table1
    set col4 = isnull(@col4, col4),
        col5 = isnull(@col5, col5)
    output inserted.col4, inserted.col5 into @inserted (col4, col5)
    where col1 = @col1

-- get the values defaulted into the table (optional)
select @col4 = col4, @col5 = col5 from @inserted

Cheers...

" app-release.apk" how to change this default generated apk name

You might get the error with the latest android gradle plugin (3.0):

Cannot set the value of read-only property 'outputFile'

According to the migration guide, we should use the following approach now:

applicationVariants.all { variant ->
    variant.outputs.all {
        outputFileName = "${applicationName}_${variant.buildType.name}_${defaultConfig.versionName}.apk"
    }
}

Note 2 main changes here:

  1. all is used now instead of each to iterate over the variant outputs.
  2. outputFileName property is used instead of mutating a file reference.

.htaccess redirect all pages to new domain

<IfModule mod_rewrite.c>
  RewriteEngine On
  RewriteCond %{HTTP_HOST} ^olddomain.com$ [OR]
  RewriteCond %{HTTP_HOST} ^www.olddomain.com$
  RewriteRule (.*)$ http://www.newdomain.com/$1 [R=301,L]
</IfModule>

This worked for me

How to make a page redirect using JavaScript?

You can append the values in the query string for the next page to see and process. You can wrap them inside the link tags:

<a href="your_page.php?var1=value1&var2=value2">

You separate each of those values with the & sign.

Or you can create this on a button click like this:

<input type="button" onclick="document.location.href = 'your_page.php?var1=value1&var2=value2';">

MySQL: View with Subquery in the FROM Clause Limitation

It appears to be a known issue.

http://dev.mysql.com/doc/refman/5.1/en/unnamed-views.html

http://bugs.mysql.com/bug.php?id=16757

Many IN queries can be re-written as (left outer) joins and an IS (NOT) NULL of some sort. for example

SELECT * FROM FOO WHERE ID IN (SELECT ID FROM FOO2)

can be re-written as

SELECT FOO.* FROM FOO JOIN FOO2 ON FOO.ID=FOO2.ID

or

SELECT * FROM FOO WHERE ID NOT IN (SELECT ID FROM FOO2)

can be

SELECT FOO.* FROM FOO 
LEFT OUTER JOIN FOO2 
ON FOO.ID=FOO2.ID WHERE FOO.ID IS NULL

Is it a bad practice to use an if-statement without curly braces?

Having the braces right from the first moment should help to prevent you from ever having to debug this:

if (statement)
     do this;
else
     do this;
     do that;

JsonParseException: Unrecognized token 'http': was expecting ('true', 'false' or 'null')

We have the following string which is a valid JSON ...

Clearly the JSON parser disagrees!

However, the exception says that the error is at "line 1: column 9", and there is no "http" token near the beginning of the JSON. So I suspect that the parser is trying to parse something different than this string when the error occurs.

You need to find what JSON is actually being parsed. Run the application within a debugger, set a breakpoint on the relevant constructor for JsonParseException ... then find out what is in the ByteArrayInputStream that it is attempting to parse.

How to refer to Excel objects in Access VBA?

Inside a module

Option Explicit
dim objExcelApp as Excel.Application
dim wb as Excel.Workbook

sub Initialize()
   set objExcelApp = new Excel.Application
end sub

sub ProcessDataWorkbook()
    dim ws as Worksheet
    set wb = objExcelApp.Workbooks.Open("path to my workbook")
    set ws = wb.Sheets(1)

    ws.Cells(1,1).Value = "Hello"
    ws.Cells(1,2).Value = "World"

    'Close the workbook
    wb.Close
    set wb = Nothing
end sub

sub Release()
   set objExcelApp = Nothing
end sub

Can you use @Autowired with static fields?

@Autowired can be used with setters so you could have a setter modifying an static field.

Just one final suggestion... DON'T

Excel VBA Run-time Error '32809' - Trying to Understand it

My solution ( may not work for you)

Open the application on a machine that is flagging the error. Change the VB code in some way. ( I added one comment line of code of no consequence into one of the macros)

Sheets(sheetName).Select 'comment of no consequence

and save it. This causes a recompile. Close and re-open - all fixed.

Hope this makes sense and helps

Grant

When should you use constexpr capability in C++11?

It can enable some new optimisations. const traditionally is a hint for the type system, and cannot be used for optimisation (e.g. a const member function can const_cast and modify the object anyway, legally, so const cannot be trusted for optimisation).

constexpr means the expression really is constant, provided the inputs to the function are const. Consider:

class MyInterface {
public:
    int GetNumber() const = 0;
};

If this is exposed in some other module, the compiler can't trust that GetNumber() won't return different values each time it's called - even consecutively with no non-const calls in between - because const could have been cast away in the implementation. (Obviously any programmer who did this ought to be shot, but the language permits it, therefore the compiler must abide by the rules.)

Adding constexpr:

class MyInterface {
public:
    constexpr int GetNumber() const = 0;
};

The compiler can now apply an optimisation where the return value of GetNumber() is cached and eliminate additional calls to GetNumber(), because constexpr is a stronger guarantee that the return value won't change.

How to format LocalDate to string?

A pretty nice way to do this is to use SimpleDateFormat I'll show you how:

SimpleDateFormat sdf = new SimpleDateFormat("d MMMM YYYY");
Date d = new Date();
sdf.format(d);

I see that you have the date in a variable:

sdf.format(variable_name);

Cheers.

EventListener Enter Key

Here is a version of the currently accepted answer (from @Trevor) with key instead of keyCode:

document.querySelector('#txtSearch').addEventListener('keypress', function (e) {
    if (e.key === 'Enter') {
      // code for enter
    }
});

Android Endless List

Just wanted to contribute a solution that I used for my app.

It is also based on the OnScrollListener interface, but I found it to have a much better scrolling performance on low-end devices, since none of the visible/total count calculations are carried out during the scroll operations.

  1. Let your ListFragment or ListActivity implement OnScrollListener
  2. Add the following methods to that class:

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem,
            int visibleItemCount, int totalItemCount) {
        //leave this empty
    }
    
    @Override
    public void onScrollStateChanged(AbsListView listView, int scrollState) {
        if (scrollState == SCROLL_STATE_IDLE) {
            if (listView.getLastVisiblePosition() >= listView.getCount() - 1 - threshold) {
                currentPage++;
                //load more list items:
                loadElements(currentPage);
            }
        }
    }
    

    where currentPage is the page of your datasource that should be added to your list, and threshold is the number of list items (counted from the end) that should, if visible, trigger the loading process. If you set threshold to 0, for instance, the user has to scroll to the very end of the list in order to load more items.

  3. (optional) As you can see, the "load-more check" is only called when the user stops scrolling. To improve usability, you may inflate and add a loading indicator to the end of the list via listView.addFooterView(yourFooterView). One example for such a footer view:

    <?xml version="1.0" encoding="utf-8"?>
    
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/footer_layout"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:padding="10dp" >
    
        <ProgressBar
            android:id="@+id/progressBar1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_gravity="center_vertical" />
    
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_toRightOf="@+id/progressBar1"
            android:padding="5dp"
            android:text="@string/loading_text" />
    
    </RelativeLayout>
    
  4. (optional) Finally, remove that loading indicator by calling listView.removeFooterView(yourFooterView) if there are no more items or pages.

PHP - Redirect and send data via POST

Yes, you can do this in PHP e.g. in

Silex or Symfony3

using subrequest

$postParams = array(
    'email' => $request->get('email'),
    'agree_terms' => $request->get('agree_terms'),
);

$subRequest = Request::create('/register', 'POST', $postParams);
return $app->handle($subRequest, HttpKernelInterface::SUB_REQUEST, false);

ASP.NET Core Identity - get current user

For context, I created a project using the ASP.NET Core 2 Web Application template. Then, select the Web Application (MVC) then hit the Change Authentication button and select Individual User accounts.

There is a lot of infrastructure built up for you from this template. Find the ManageController in the Controllers folder.

This ManageController class constructor requires this UserManager variable to populated:

private readonly UserManager<ApplicationUser> _userManager;

Then, take a look at the the [HttpPost] Index method in this class. They get the current user in this fashion:

var user = await _userManager.GetUserAsync(User);

As a bonus note, this is where you want to update any custom fields to the user Profile you've added to the AspNetUsers table. Add the fields to the view, then submit those values to the IndexViewModel which is then submitted to this Post method. I added this code after the default logic to set the email address and phone number:

user.FirstName = model.FirstName;
user.LastName = model.LastName;
user.Address1 = model.Address1;
user.Address2 = model.Address2;
user.City = model.City;
user.State = model.State;
user.Zip = model.Zip;
user.Company = model.Company;
user.Country = model.Country;
user.SetDisplayName();
user.SetProfileID();

_dbContext.Attach(user).State = EntityState.Modified;
_dbContext.SaveChanges();

How can I get a list of all values in select box?

Change:

x.length

to:

x.options.length

Link to fiddle

And I agree with Abraham - you might want to use text instead of value

Update
The reason your fiddle didn't work was because you chose the option: "onLoad" instead of: "No wrap - in "

What is trunk, branch and tag in Subversion?

To use Subversion in Visual Studio 2008, install TortoiseSVN and AnkhSVN.

TortoiseSVN is a really easy to use Revision control / version control / source control software for Windows. Since it's not an integration for a specific IDE you can use it with whatever development tools you like. TortoiseSVN is free to use. You don't need to get a loan or pay a full years salary to use it.

AnkhSVN is a Subversion SourceControl Provider for Visual Studio. The software allows you to perform the most common version control operations directly from inside the Microsoft Visual Studio IDE. With AnkhSVN you no longer need to leave your IDE to perform tasks like viewing the status of your source code, updating your Subversion working copy and committing changes. You can even browse your repository and you can plug-in your favorite diff tool.

How do you change the datatype of a column in SQL Server?

Don't forget nullability.

ALTER TABLE <schemaName>.<tableName>
ALTER COLUMN <columnName> nvarchar(200) [NULL|NOT NULL]

How to edit a text file in my terminal

Open the file again using vi. and then press " i " or press insert key ,

For save and quit

  Enter Esc    

and write the following command

  :wq

without save and quit

  :q!

Facebook Open Graph not clearing cache

Really easy solve. Tested and working. You just need to generate a new url when you update your meta tags. It's as simple as adding a "&cacheBuster=1" to your url. If you change the meta tags, just increment the "&cacheBuster=2"

Orginal URL

www.example.com

URL when og meta tags are updated:

www.example.com?cacheBuster=1

URL when og meta tags are updated again:

www.example.com?cacheBuster=2

Facebook will treat each like a new url and get fresh meta data.

MVC 4 @Scripts "does not exist"

I solve this problem in MvcMusicStore by add this part of code in _Layout.cshtml

@if (IsSectionDefined("scripts")) 
{
       @RenderSection("scripts", required: false)
}

and remove this code from Edit.cshtml

 @section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

Run the program inshallah will work with you.

Create a user with all privileges in Oracle

There are 2 differences:

2 methods creating a user and granting some privileges to him

create user userName identified by password;
grant connect to userName;

and

grant connect to userName identified by password;

do exactly the same. It creates a user and grants him the connect role.

different outcome

resource is a role in oracle, which gives you the right to create objects (tables, procedures, some more but no views!). ALL PRIVILEGES grants a lot more of system privileges.

To grant a user all privileges run you first snippet or

grant all privileges to userName identified by password;

java.sql.SQLException Parameter index out of range (1 > number of parameters, which is 0)

This is an issue with the jdbc Driver version. I had this issue when I was using mysql-connector-java-commercial-5.0.3-bin.jar but when I changed to a later driver version mysql-connector-java-5.1.22.jar, the issue was fixed.

How to embed an autoplaying YouTube video in an iframe?

This works in Chrome but not Firefox 3.6 (warning: RickRoll video):

<iframe width="420" height="345" src="http://www.youtube.com/embed/oHg5SJYRHA0?autoplay=1" frameborder="0" allowfullscreen></iframe>

The JavaScript API for iframe embeds exists, but is still posted as an experimental feature.

UPDATE: The iframe API is now fully supported and "Creating YT.Player objects - Example 2" shows how to set "autoplay" in JavaScript.

Calculate difference between two dates (number of days)?

For a and b as two DateTime types:

DateTime d = DateTime.Now;
DateTime c = DateTime.Now;
c = d.AddDays(145);
string cc;
Console.WriteLine(d);
Console.WriteLine(c);
var t = (c - d).Days;
Console.WriteLine(t);
cc = Console.ReadLine();

how to get program files x86 env variable?

IMHO, one point that is missing in this discussion is that whatever variable you use, it is guaranteed to always point at the appropriate folder. This becomes critical in the rare cases where Windows is installed on a drive other than C:\

Concatenating strings in C, which method is more efficient?

size_t lf = strlen(first);
size_t ls = strlen(second);

char *both = (char*) malloc((lf + ls + 2) * sizeof(char));

strcpy(both, first);

both[lf] = ' ';
strcpy(&both[lf+1], second);

What is SELF JOIN and when would you use it?

Well, one classic example is where you wanted to get a list of employees and their immediate managers:

select e.employee as employee, b.employee as boss
from emptable e, emptable b
where e.manager_id = b.empolyee_id
order by 1

It's basically used where there is any relationship between rows stored in the same table.

  • employees.
  • multi-level marketing.
  • machine parts.

And so on...

Android : How to set onClick event for Button in List item of ListView

In Adapter Class

public View getView(final int position, View convertView, ViewGroup parent) {
    LayoutInflater inflater = getLayoutInflater();
    View row = inflater.inflate(R.layout.vehicals_details_row, parent, false);
    Button deleteImageView = (Button) row.findViewById(R.id.DeleteImageView);
    deleteImageView.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            //...
        }
    });
}

But you can get an issue - listView row not clickable. Solution:

  • make ListView focusable android:focusable="true"
  • Button not focusable android:focusable="false"

Position buttons next to each other in the center of page

.wrapper{
  float: left;
  width: 100%;
  text-align: center;
  position: relative;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}
.button{
  display:inline-block;
}
<div class="wrapper">
  <button class="button">Button1</button>
  <button class="button">Button2</button>
</div>

Undefined variable: $_SESSION

Turned out there was some extra code in the AppModel that was messing things up:

in beforeFind and afterFind:

App::Import("Session");
$session = new CakeSession();
$sim_id = $session->read("Simulation.id");

I don't know why, but that was what the problem was. Removing those lines fixed the issue I was having.

How to get ASCII value of string in C#

Do you mean you only want the alphabetic characters and not the digits? So you want "quality" as a result? You can use Char.IsLetter or Char.IsDigit to filter them out one by one.

string s = "9quali52ty3";
StringBuilder result = new StringBuilder();
foreach(char c in s)
{
  if (Char.IsLetter(c))  
    result.Add(c);
}
Console.WriteLine(result);  // quality

AttributeError: 'numpy.ndarray' object has no attribute 'append'

I got this error after change a loop in my program, let`s see:

for ...
  for ... 
     x_batch.append(one_hot(int_word, vocab_size))
     y_batch.append(one_hot(int_nb, vocab_size, value))
  ...
  ...
  if ...
        x_batch = np.asarray(x_batch)
        y_batch = np.asarray(y_batch)
...

In fact, I was reusing the variable and forgot to reset them inside the external loop, like the comment of John Lyon:

for ...
  x_batch = []
  y_batch = []
  for ... 
     x_batch.append(one_hot(int_word, vocab_size))
     y_batch.append(one_hot(int_nb, vocab_size, value))
  ...
  ...
  if ...
        x_batch = np.asarray(x_batch)
        y_batch = np.asarray(y_batch)
...

Then, check if you are using np.asarray() or something like that.

How to hide Bootstrap modal with javascript?

I found the correct solution you can use this code

$('.close').click(); 

Why is Chrome showing a "Please Fill Out this Field" tooltip on empty fields?

Put novalidate="novalidate" on <form> tag.

<form novalidate="novalidate">
...
</form>

In XHTML, attribute minimization is forbidden, and the novalidate attribute must be defined as <form novalidate="novalidate">.

http://www.w3schools.com/tags/att_form_novalidate.asp

How do I check in SQLite whether a table exists?

Using a simple SELECT query is - in my opinion - quite reliable. Most of all it can check table existence in many different database types (SQLite / MySQL).

SELECT 1 FROM table;

It makes sense when you can use other reliable mechanism for determining if the query succeeded (for example, you query a database via QSqlQuery in Qt).

Missing Microsoft RDLC Report Designer in Visual Studio

If you did a custom installation you need to add Microsoft Sql Server Data Tools. After that you can add Reportviwer to your webform.

HTTPS setup in Amazon EC2

This answer is focused to someone that buy a domain in another site (as GoDaddy) and want to use the Amazon free certificate with Certificate Manager

This answer uses Amazon Classic Load Balancer (paid) see the pricing before using it


Step 1 - Request a certificate with Certificate Manager

Go to Certificate Manager > Request Certificate > Request a public certificate

On Domain name you will add myprojectdomainname.com and *.myprojectdomainname.com and go on Next

Chose Email validation and Confirm and Request

Open the email that you have received (on the email account that you have buyed the domain) and aprove the request

After this, check if the validation status of myprojectdomainname.com and *.myprojectdomainname.com is sucess, if is sucess you can continue to Step 2

Step 2 - Create a Security Group to a Load Balancer

On EC2 go to Security Groups > and Create a Security Group and add the http and https inbound

It will be something like: enter image description here

Step 3 - Create the Load Balancer

EC2 > Load Balancer > Create Load Balancer > Classic Load Balancer (Third option)

Create LB inside - the vpc of your project On Load Balancer Protocol add Http and Https enter image description here

Next > Select exiting security group

Choose the security group that you have create in the previous step

Next > Choose certificate from ACM

Select the certificate of the step 1

Next >

on Health check i've used the ping path / (one slash instead of /index.html)

Step 4 - Associate your instance with the security group of load balancer

EC2 > Instances > click on your project > Actions > Networking > Change Security Groups

Add the Security Group of your Load Balancer

Step 5

EC2 > Load Balancer > Click on the load balancer that you have created > copy the DNS Name (A Record), it will be something like myproject-2021611191.us-east-1.elb.amazonaws.com

Go to Route 53 > Routes Zones > click on the domain name > Go to Records Sets (If you are don't have your domain here, create a hosted zone with Domain Name: myprojectdomainname.com and Type: Public Hosted Zone)

Check if you have a record type A (probably not), create/edit record set with name empty, type A, alias Yes and Target the dns that you have copied

Create also a new Record Set of type A, name *.myprojectdomainname.com, alias Yes and Target your domain (myprojectdomainname.com). This will make possible access your site with www.myprojectdomainname.com and subsite.myprojectdomainname.com. Note: You will need to configure your reverse proxy (Nginx/Apache) to do so.

On NS copy the 4 Name Servers values to use on the next Step, it will be something like:

ns-362.awsdns-45.com ns-1558.awsdns-02.co.uk ns-737.awsdns-28.net ns-1522.awsdns-62.org

Go to EC2 > Instances > And copy the IPv4 Public IP too

Step 6

On the domain register site that you have buyed the domain (in my case GoDaddy)

Change the routing to http : <Your IPv4 Public IP Number> and select Forward with masking

Change the Name Servers (NS) to the 4 NS that you have copied, this can take 48 hours to make effect

Javascript window.print() in chrome, closing new window or tab instead of cancelling print leaves javascript blocked in parent window

Run this code It will open google print service popup.

function openPrint(x) {

   if (x > 0) { 
       openPrint(--x); print(x); openPrint(--x);
   }

}

Try it on console where x is integer .

openPrint(1);   // Will open Chrome Print Popup Once
openPrint(2);   // Will open Chrome Print Popup Twice after 1st close and so on

Thanks

python pandas convert index to datetime

I just give other option for this question - you need to use '.dt' in your code:

_x000D_
_x000D_
import pandas as pd_x000D_
_x000D_
df.index = pd.to_datetime(df.index)_x000D_
_x000D_
#for get year_x000D_
df.index.dt.year_x000D_
_x000D_
#for get month_x000D_
df.index.dt.month_x000D_
_x000D_
#for get day_x000D_
df.index.dt.day_x000D_
_x000D_
#for get hour_x000D_
df.index.dt.hour_x000D_
_x000D_
#for get minute_x000D_
df.index.dt.minute
_x000D_
_x000D_
_x000D_

Apache 2.4.6 on Ubuntu Server: Client denied by server configuration (PHP FPM) [While loading PHP file]

I recently ran into the same problem. I had to change my virtual hosts from:

<VirtualHost *:80>
  ServerName local.example.com

  DocumentRoot /home/example/public

  <Directory />
    Order allow,deny
    Allow from all
  </Directory>
</VirtualHost>

To:

<VirtualHost *:80>
  ServerName local.example.com

  DocumentRoot /home/example/public

  <Directory />
    Options All
    AllowOverride All
    Require all granted
  </Directory>
</VirtualHost>

Powershell: convert string to number

I demonstrate how to receive a string, for example "-484876800000" and tryparse the string to make sure it can be assigned to a long. I calculate the Date from universaltime and return a string. When you convert a string to a number, you must decide the numeric type and precision and test if the string data can be parse, otherwise, it will throw and error.

function universalToDate
{
 param (
    $paramValue
  )
    $retVal=""


    if ($paramValue)
    {
        $epoch=[datetime]'1/1/1970'
        [long]$returnedLong = 0
        [bool]$result = [long]::TryParse($paramValue,[ref]$returnedLong)
        if ($result -eq 1)
        {
            $val=$returnedLong/1000.0
            $retVal=$epoch.AddSeconds($val).ToString("yyyy-MM-dd")
        }
    }
    else
    {
        $retVal=$null
    }
    return($retVal)
 }

How to use UIPanGestureRecognizer to move object? iPhone/iPad

if ([recognizer state] == UIGestureRecognizerStateChanged)    
{
    CGPoint translation1 = [recognizer translationInView:main_view];
    img12.center=CGPointMake(img12.center.x+translation1.x, img12.center.y+ translation1.y);
    [recognizer setTranslation:CGPointMake(0, 0) inView:main_view];

    recognizer.view.center=CGPointMake(recognizer.view.center.x+translation1.x, recognizer.view.center.y+ translation1.y);
}

-(void)move:(UIPanGestureRecognizer*)recognizer
{
    if ([recognizer state] == UIGestureRecognizerStateChanged)    
    {
        CGPoint translation = [recognizer translationInView:self.view];
        recognizer.view.center=CGPointMake(recognizer.view.center.x+translation.x, recognizer.view.center.y+ translation.y);
        [recognizer setTranslation:CGPointMake(0, 0) inView:self.view];
    }
}

Bootstrap 3 - Responsive mp4-video

Simply add class="img-responsive" to the video tag. I'm doing this on a current project, and it works. It doesn't need to be wrapped in anything.

<video class="img-responsive" src="file.mp4" autoplay loop/>

Bootstrap with jQuery Validation Plugin

I used this for radio's:

    if (element.prop("type") === "checkbox" || element.prop("type") === "radio") {
        error.appendTo(element.parent().parent());
    }
    else if (element.parent(".input-group").length) {
        error.insertAfter(element.parent());
    }
    else {
        error.insertAfter(element);
    }

this way the error is displayed under last radio option.

How do I free memory in C?

You actually can't manually "free" memory in C, in the sense that the memory is released from the process back to the OS ... when you call malloc(), the underlying libc-runtime will request from the OS a memory region. On Linux, this may be done though a relatively "heavy" call like mmap(). Once this memory region is mapped to your program, there is a linked-list setup called the "free store" that manages this allocated memory region. When you call malloc(), it quickly looks though the free-store for a free block of memory at the size requested. It then adjusts the linked list to reflect that there has been a chunk of memory taken out of the originally allocated memory pool. When you call free() the memory block is placed back in the free-store as a linked-list node that indicates its an available chunk of memory.

If you request more memory than what is located in the free-store, the libc-runtime will again request more memory from the OS up to the limit of the OS's ability to allocate memory for running processes. When you free memory though, it's not returned back to the OS ... it's typically recycled back into the free-store where it can be used again by another call to malloc(). Thus, if you make a lot of calls to malloc() and free() with varying memory size requests, it could, in theory, cause a condition called "memory fragmentation", where there is enough space in the free-store to allocate your requested memory block, but not enough contiguous space for the size of the block you've requested. Thus the call to malloc() fails, and you're effectively "out-of-memory" even though there may be plenty of memory available as a total amount of bytes in the free-store.

onclick event pass <li> id or value

I prefer to use the HTML5 data API, check this documentation:

A example

_x000D_
_x000D_
$('#some-list li').click(function() {_x000D_
  var textLoaded = 'Loading element with id='_x000D_
         + $(this).data('id');_x000D_
   $('#loading-content').text(textLoaded);_x000D_
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<ul id='some-list'>_x000D_
  <li data-id='1'>One </li>_x000D_
  <li data-id='2'>Two </li>_x000D_
  <!-- ... more li -->_x000D_
  <li data-id='n'>Other</li>_x000D_
</ul>_x000D_
_x000D_
<h1 id='loading-content'></h1>
_x000D_
_x000D_
_x000D_

Step out of current function with GDB

You can use the finish command.

finish: Continue running until just after function in the selected stack frame returns. Print the returned value (if any). This command can be abbreviated as fin.

(See 5.2 Continuing and Stepping.)

linux shell script: split string, put them in an array then loop through them

Here's a variation on ashirazi's answer which doesn't rely on $IFS. It does have its own issues which I ouline below.

sentence="one;two;three"
sentence=${sentence//;/$'\n'}  # change the semicolons to white space
for word in $sentence
do
    echo "$word"
done

Here I've used a newline, but you could use a tab "\t" or a space. However, if any of those characters are in the text it will be split there, too. That's the advantage of $IFS - it can not only enable a separator, but disable the default ones. Just make sure you save its value before you change it - as others have suggested.

How do I determine file encoding in OS X?

Synalyze It! allows to compare text or bytes in all encodings the ICU library offers. Using that feature you usually see immediately which code page makes sense for your data.

MAX function in where clause mysql

The syntax you have used is incorrect. The query should be something like:

SELECT column_name(s) FROM tablename WHERE id = (SELECT MAX(id) FROM tablename)

How to delete node from XML file using C#

You can use Linq to XML to do this:

XDocument doc = XDocument.Load("input.xml");
var q = from node in doc.Descendants("Setting")
        let attr = node.Attribute("name")
        where attr != null && attr.Value == "File1"
        select node;
q.ToList().ForEach(x => x.Remove());
doc.Save("output.xml");

Can I write or modify data on an RFID tag?

Some RFID chips are read-write, the majority are read-only. You can find out if your chip is read-only by checking the datasheet.

Debugging Spring configuration

If you use Spring Boot, you can also enable a “debug” mode by starting your application with a --debug flag.

java -jar myapp.jar --debug

You can also specify debug=true in your application.properties.

When the debug mode is enabled, a selection of core loggers (embedded container, Hibernate, and Spring Boot) are configured to output more information. Enabling the debug mode does not configure your application to log all messages with DEBUG level.

Alternatively, you can enable a “trace” mode by starting your application with a --trace flag (or trace=true in your application.properties). Doing so enables trace logging for a selection of core loggers (embedded container, Hibernate schema generation, and the whole Spring portfolio).

https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-logging.html

Call function with setInterval in jQuery?

setInterval(function() {
    updatechat();
}, 2000);

function updatechat() {
    alert('hello world');
}

Spring 3 RequestMapping: Get path value

Yes the restOfTheUrl is not returning only required value but we can get the value by using UriTemplate matching.

I have solved the problem, so here the working solution for the problem:

@RequestMapping("/{id}/**")
public void foo(@PathVariable("id") int id, HttpServletRequest request) {
String restOfTheUrl = (String) request.getAttribute(
    HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);
    /*We can use UriTemplate to map the restOfTheUrl*/
    UriTemplate template = new UriTemplate("/{id}/{value}");        
    boolean isTemplateMatched = template.matches(restOfTheUrl);
    if(isTemplateMatched) {
        Map<String, String> matchTemplate = new HashMap<String, String>();
        matchTemplate = template.match(restOfTheUrl);
        String value = matchTemplate.get("value");
       /*variable `value` will contain the required detail.*/
    }
}

Flutter- wrapping text

The Flexible does the trick

new Container(
       child: Row(
         children: <Widget>[
            Flexible(
               child: new Text("A looooooooooooooooooong text"))
                ],
        ));

This is the official doc https://flutter.dev/docs/development/ui/layout#lay-out-multiple-widgets-vertically-and-horizontally on how to arrange widgets.

Remember that Flexible and also Expanded, should only be used within a Column, Row or Flex, because of the Incorrect use of ParentDataWidget.

The solution is not the mere Flexible

How to read integer value from the standard input in Java

Second answer above is the most simple one.

int n = Integer.parseInt(System.console().readLine());

The question is "How to read from standard input".

A console is a device typically associated to the keyboard and display from which a program is launched.

You may wish to test if no Java console device is available, e.g. Java VM not started from a command line or the standard input and output streams are redirected.

Console cons;
if ((cons = System.console()) == null) {
    System.err.println("Unable to obtain console");
    ...
}

Using console is a simple way to input numbers. Combined with parseInt()/Double() etc.

s = cons.readLine("Enter a int: ");
int i = Integer.parseInt(s);    

s = cons.readLine("Enter a double: ");
double d = Double.parseDouble(s);

How to auto-reload files in Node.js?

node-dev works great. npm install node-dev

It even gives a desktop notification when the server is reloaded and will give success or errors on the message.

start your app on command line with:

node-dev app.js

Run cron job only if it isn't already running

Consider using pgrep (if available) rather than ps piped through grep if you're going to go that route. Though, personally, I've got a lot of mileage out of scripts of the form

while(1){
  call script_that_must_run
  sleep 5
}

Though this can fail and cron jobs are often the best way for essential stuff. Just another alternative.

Getting the last revision number in SVN?

You can try the below command:

svn info -r 'HEAD' | grep Revision: | awk -F' ' '{print $2}'

ffprobe or avprobe not found. Please install one

  • Update your version of youtube-dl to the lastest as older version might not support.

     pip install --upgrade youtube_dl
    
  • Install 'ffmpeg' and 'ffprobe' module

     pip install ffmpeg
     pip install ffprobe
    
  • If you face the same issue, then download ffmpeg builds and put all the .exe files to Script folder($path: "Python\Python38-32\Scripts") (Windows OS only)

Convert python datetime to timestamp in milliseconds

In Python 3 this can be done in 2 steps:

  1. Convert timestring to datetime object
  2. Multiply the timestamp of the datetime object by 1000 to convert it to milliseconds.

For example like this:

from datetime import datetime

dt_obj = datetime.strptime('20.12.2016 09:38:42,76',
                           '%d.%m.%Y %H:%M:%S,%f')
millisec = dt_obj.timestamp() * 1000

print(millisec)

Output:

1482223122760.0

strptime accepts your timestring and a format string as input. The timestring (first argument) specifies what you actually want to convert to a datetime object. The format string (second argument) specifies the actual format of the string that you have passed.

Here is the explanation of the format specifiers from the official documentation:

  • %d - Day of the month as a zero-padded decimal number.
  • %m - Month as a zero-padded decimal number.
  • %Y - Year with century as a decimal number
  • %H - Hour (24-hour clock) as a zero-padded decimal number.
  • %M - Minute as a zero-padded decimal number.
  • %S - Second as a zero-padded decimal number.
  • %f - Microsecond as a decimal number, zero-padded on the left.

AngularJS - ng-if check string empty value

This is what may be happening, if the value of item.photo is undefined then item.photo != '' will always show as true. And if you think logically it actually makes sense, item.photo is not an empty string (so this condition comes true) since it is undefined.

Now for people who are trying to check if the value of input is empty or not in Angular 6, can go by this approach.

Lets say this is the input field -

_x000D_
_x000D_
<input type="number" id="myTextBox" name="myTextBox"_x000D_
 [(ngModel)]="response.myTextBox"_x000D_
            #myTextBox="ngModel">
_x000D_
_x000D_
_x000D_

To check if the field is empty or not this should be the script.

_x000D_
_x000D_
<div *ngIf="!myTextBox.value" style="color:red;">_x000D_
 Your field is empty_x000D_
</div>
_x000D_
_x000D_
_x000D_

Do note the subtle difference between the above answer and this answer. I have added an additional attribute .value after my input name myTextBox.
I don't know if the above answer worked for above version of Angular, but for Angular 6 this is how it should be done.

Convert String to System.IO.Stream

this is old but for help :

you can also use the stringReader stream

string str = "asasdkopaksdpoadks";
StringReader TheStream = new StringReader( str );

Comment out HTML and PHP together

I found the following solution pretty effective if you need to comment a lot of nested HTML + PHP code.

Wrap all the content in this:

<?php
    if(false){
?>

Here goes your PHP + HTML code

<?php
    }
?>

How to validate an e-mail address in swift?

As a String class extension

SWIFT 4

extension String {
    func isValidEmail() -> Bool {
        // here, `try!` will always succeed because the pattern is valid
        let regex = try! NSRegularExpression(pattern: "^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$", options: .caseInsensitive)
        return regex.firstMatch(in: self, options: [], range: NSRange(location: 0, length: count)) != nil
    }
}

Usage

if "rdfsdsfsdfsd".isValidEmail() {

}

How to know which version of Symfony I have?

Maybe the anwswers here are obsolete... in any case, for me running Symfony 4, it is easy Just type symfony -V from the command line.

enter image description here

No ConcurrentList<T> in .Net 4.0?

The reason why there is no ConcurrentList is because it fundamentally cannot be written. The reason why is that several important operations in IList rely on indices, and that just plain won't work. For example:

int catIndex = list.IndexOf("cat");
list.Insert(catIndex, "dog");

The effect that the author is going after is to insert "dog" before "cat", but in a multithreaded environment, anything can happen to the list between those two lines of code. For example, another thread might do list.RemoveAt(0), shifting the entire list to the left, but crucially, catIndex will not change. The impact here is that the Insert operation will actually put the "dog" after the cat, not before it.

The several implementations that you see offered as "answers" to this question are well-meaning, but as the above shows, they don't offer reliable results. If you really want list-like semantics in a multithreaded environment, you can't get there by putting locks inside the list implementation methods. You have to ensure that any index you use lives entirely inside the context of the lock. The upshot is that you can use a List in a multithreaded environment with the right locking, but the list itself cannot be made to exist in that world.

If you think you need a concurrent list, there are really just two possibilities:

  1. What you really need is a ConcurrentBag
  2. You need to create your own collection, perhaps implemented with a List and your own concurrency control.

If you have a ConcurrentBag and are in a position where you need to pass it as an IList, then you have a problem, because the method you're calling has specified that they might try to do something like I did above with the cat & dog. In most worlds, what that means is that the method you're calling is simply not built to work in a multi-threaded environment. That means you either refactor it so that it is or, if you can't, you're going to have to handle it very carefully. You you'll almost certainly be required to create your own collection with its own locks, and call the offending method within a lock.

Creating a file name as a timestamp in a batch job

used Martin's suggestion with a little tweak to add time stamp to the file name:

forfiles /p [foldername] /m rsync2.log /c "cmd /c ren @file %DATE:~6,4%%DATE:~3,2%%DATE:~0,2%_%time:~-11,2%-%time:~-8,2%-%time:~-5,2%-@file

For the 10:17:21 23/10/2019 The result is:

20191023_10-17-21-rsync2.log

How to POST JSON request using Apache HttpClient?

Apache HttpClient doesn't know anything about JSON, so you'll need to construct your JSON separately. To do so, I recommend checking out the simple JSON-java library from json.org. (If "JSON-java" doesn't suit you, json.org has a big list of libraries available in different languages.)

Once you've generated your JSON, you can use something like the code below to POST it

StringRequestEntity requestEntity = new StringRequestEntity(
    JSON_STRING,
    "application/json",
    "UTF-8");

PostMethod postMethod = new PostMethod("http://example.com/action");
postMethod.setRequestEntity(requestEntity);

int statusCode = httpClient.executeMethod(postMethod);

Edit

Note - The above answer, as asked for in the question, applies to Apache HttpClient 3.1. However, to help anyone looking for an implementation against the latest Apache client:

StringEntity requestEntity = new StringEntity(
    JSON_STRING,
    ContentType.APPLICATION_JSON);

HttpPost postMethod = new HttpPost("http://example.com/action");
postMethod.setEntity(requestEntity);

HttpResponse rawResponse = httpclient.execute(postMethod);

Elegant way to report missing values in a data.frame

Another function that would help you look at missing data would be df_status from funModeling library

library(funModeling)

iris.2 is the iris dataset with some added NAs.You can replace this with your dataset.

df_status(iris.2)

This will give you the number and percentage of NAs in each column.

jQuery creating objects

Another way to make objects in Javascript using JQuery, getting data from the dom and pass it to the object Box and, for example, store them in an array of Boxes, could be:

var box = {}; // my object
var boxes =  []; // my array

$('div.test').each(function (index, value) {
    color = $('p', this).attr('color');
    box = {
        _color: color // being _color a property of `box`
    }
    boxes.push(box);
});

Hope it helps!

Set value of textbox using JQuery

1) you are calling it wrong way try:

$(input[name="searchBar"]).val('hi')

2) if it doesn't work call your .js file at the end of the page or trigger your function on document.ready event

$(document).ready(function() {
  $(input[name="searchBar"]).val('hi');
});

Configure nginx with multiple locations with different root folders on subdomain

A little more elaborate example.

Setup: You have a website at example.com and you have a web app at example.com/webapp

...
server {
  listen 443 ssl;
  server_name example.com;

  root   /usr/share/nginx/html/website_dir;
  index  index.html index.htm;
  try_files $uri $uri/ /index.html;

  location /webapp/ {
    alias  /usr/share/nginx/html/webapp_dir/;
    index  index.html index.htm;
    try_files $uri $uri/ /webapp/index.html;
  }
}
...

I've named webapp_dir and website_dir on purpose. If you have matching names and folders you can use the root directive.

This setup works and is tested with Docker.

NB!!! Be careful with the slashes. Put them exactly as in the example.

Get Date Object In UTC format in Java

You can subtract the time zone difference from now.

final Calendar calendar  = Calendar.getInstance();
final int      utcOffset = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET);
final long     tempDate  = new Date().getTime();

return new Date(tempDate - utcOffset);

Adjust UILabel height depending on the text

sizeWithFont constrainedToSize:lineBreakMode: is the method to use. An example of how to use it is below:

//Calculate the expected size based on the font and linebreak mode of your label
// FLT_MAX here simply means no constraint in height
CGSize maximumLabelSize = CGSizeMake(296, FLT_MAX);

CGSize expectedLabelSize = [yourString sizeWithFont:yourLabel.font constrainedToSize:maximumLabelSize lineBreakMode:yourLabel.lineBreakMode];   

//adjust the label the the new height.
CGRect newFrame = yourLabel.frame;
newFrame.size.height = expectedLabelSize.height;
yourLabel.frame = newFrame;

Plotting a 3d cube, a sphere and a vector in Matplotlib

For drawing just the arrow, there is an easier method:-

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
fig = plt.figure()
ax = fig.gca(projection='3d')
ax.set_aspect("equal")

#draw the arrow
ax.quiver(0,0,0,1,1,1,length=1.0)

plt.show()

quiver can actually be used to plot multiple vectors at one go. The usage is as follows:- [ from http://matplotlib.org/mpl_toolkits/mplot3d/tutorial.html?highlight=quiver#mpl_toolkits.mplot3d.Axes3D.quiver]

quiver(X, Y, Z, U, V, W, **kwargs)

Arguments:

X, Y, Z: The x, y and z coordinates of the arrow locations

U, V, W: The x, y and z components of the arrow vectors

The arguments could be array-like or scalars.

Keyword arguments:

length: [1.0 | float] The length of each quiver, default to 1.0, the unit is the same with the axes

arrow_length_ratio: [0.3 | float] The ratio of the arrow head with respect to the quiver, default to 0.3

pivot: [ ‘tail’ | ‘middle’ | ‘tip’ ] The part of the arrow that is at the grid point; the arrow rotates about this point, hence the name pivot. Default is ‘tail’

normalize: [False | True] When True, all of the arrows will be the same length. This defaults to False, where the arrows will be different lengths depending on the values of u,v,w.

How to read GET data from a URL using JavaScript?

try this way

var url_string = window.location;
var url = new URL(url_string);
var name = url.searchParams.get("name");
var tvid = url.searchParams.get("id");

Why I've got no crontab entry on OS X when using vim?

I've never had this problem, but I create a ~/.crontab file and edit that (which allows me to back it up, Time Machine or otherwise), then run

crontab ~/.crontab

Has worked for me for 20+ years across many flavors of unix.

Select current date by default in ASP.Net Calendar control

I have tried above with above code but not working ,Here is solution to set current date selected in asp.net calendar control

dtpStartDate.SelectedDate = Convert.ToDateTime(DateTime.Now.Date);
dtpStartDate.VisibleDate = Convert.ToDateTime(DateTime.Now.ToString());

VBA: Conditional - Is Nothing

Just becuase your class object has no variables does not mean that it is nothing. Declaring and object and creating an object are two different things. Look and see if you are setting/creating the object.

Take for instance the dictionary object - just because it contains no variables does not mean it has not been created.

Sub test()

Dim dict As Object
Set dict = CreateObject("scripting.dictionary")

If Not dict Is Nothing Then
    MsgBox "Dict is something!"  '<--- This shows
Else
    MsgBox "Dict is nothing!"
End If

End Sub

However if you declare an object but never create it, it's nothing.

Sub test()

Dim temp As Object

If Not temp Is Nothing Then
    MsgBox "Temp is something!"
Else
    MsgBox "Temp is nothing!" '<---- This shows
End If

End Sub

printf with std::string?

Please don't use printf("%s", your_string.c_str());

Use cout << your_string; instead. Short, simple and typesafe. In fact, when you're writing C++, you generally want to avoid printf entirely -- it's a leftover from C that's rarely needed or useful in C++.

As to why you should use cout instead of printf, the reasons are numerous. Here's a sampling of a few of the most obvious:

  1. As the question shows, printf isn't type-safe. If the type you pass differs from that given in the conversion specifier, printf will try to use whatever it finds on the stack as if it were the specified type, giving undefined behavior. Some compilers can warn about this under some circumstances, but some compilers can't/won't at all, and none can under all circumstances.
  2. printf isn't extensible. You can only pass primitive types to it. The set of conversion specifiers it understands is hard-coded in its implementation, and there's no way for you to add more/others. Most well-written C++ should use these types primarily to implement types oriented toward the problem being solved.
  3. It makes decent formatting much more difficult. For an obvious example, when you're printing numbers for people to read, you typically want to insert thousands separators every few digits. The exact number of digits and the characters used as separators varies, but cout has that covered as well. For example:

    std::locale loc("");
    std::cout.imbue(loc);
    
    std::cout << 123456.78;
    

    The nameless locale (the "") picks a locale based on the user's configuration. Therefore, on my machine (configured for US English) this prints out as 123,456.78. For somebody who has their computer configured for (say) Germany, it would print out something like 123.456,78. For somebody with it configured for India, it would print out as 1,23,456.78 (and of course there are many others). With printf I get exactly one result: 123456.78. It is consistent, but it's consistently wrong for everybody everywhere. Essentially the only way to work around it is to do the formatting separately, then pass the result as a string to printf, because printf itself simply will not do the job correctly.

  4. Although they're quite compact, printf format strings can be quite unreadable. Even among C programmers who use printf virtually every day, I'd guess at least 99% would need to look things up to be sure what the # in %#x means, and how that differs from what the # in %#f means (and yes, they mean entirely different things).

Twitter Bootstrap inline input with dropdown

Search for the "datalist" tag.

<input list="texto_pronto" name="input_normal">
<datalist id="texto_pronto">
    <option value="texto A">
    <option value="texto B">
</datalist>

The meaning of NoInitialContextException error

The javax.naming package comprises the JNDI API. Since it's just an API, rather than an implementation, you need to tell it which implementation of JNDI to use. The implementations are typically specific to the server you're trying to talk to.

To specify an implementation, you pass in a Properties object when you construct the InitialContext. These properties specify the implementation to use, as well as the location of the server. The default InitialContext constructor is only useful when there are system properties present, but the properties are the same as if you passed them in manually.

As to which properties you need to set, that depends on your server. You need to hunt those settings down and plug them in.

Resize height with Highcharts

You must set the height of the container explicitly

#container {
    height:100%;
    width:100%;
    position:absolute; 
}

See other Stackoverflow answer

Highcharts documentation

Kendo grid date column not formatting

As far as I'm aware in order to format a date value you have to handle it in parameterMap,

$('#listDiv').kendoGrid({
            dataSource: {
                type: 'json',
                serverPaging: true,
                pageSize: 10,
                transport: {
                    read: {
                        url: '@Url.Action("_ListMy", "Placement")',
                        data: refreshGridParams,
                        type: 'POST'
                    },
                    parameterMap: function (options, operation) {
                        if (operation != "read") {
                            var d = new Date(options.StartDate);
                            options.StartDate = kendo.toString(new Date(d), "dd/MM/yyyy");
                            return options;
                        }
                        else { return options; }

                    }
                },
                schema: {
                    model: {
                        id: 'Id',
                        fields: {
                            Id: { type: 'number' },
                            StartDate: { type: 'date', format: 'dd/MM/yyyy' },
                            Area: { type: 'string' },
                            Length: { type: 'string' },
                            Display: { type: 'string' },
                            Status: { type: 'string' },
                            Edit: { type: 'string' }
                        }
                    },
                    data: "Data",
                    total: "Count"
                }
            },
            scrollable: false,
            columns:
                [
                    {
                        field: 'StartDate',
                        title: 'Start Date',
                        format: '{0:dd/MM/yyyy}',
                        width: 100
                    },

If you follow the above example and just renames objects like 'StartDate' then it should work (ignore 'data: refreshGridParams,')

For further details check out below link or just search for kendo grid parameterMap ans see what others have done.

http://docs.kendoui.com/api/framework/datasource#configuration-transport.parameterMap

when do you need .ascx files and how would you use them?

ASCX files are server-side Web application framework designed for Web development to produce dynamic Web pages.They like DLL codes but you can use there's TAGS You can write them once and use them in any places in your ASP pages.If you have a file named "Controll.ascx" then its code will named "Controll.ascx.cs". You can embed it in a ASP page to use it:

Hiding an Excel worksheet with VBA

To hide from the UI, use Format > Sheet > Hide

To hide programatically, use the Visible property of the Worksheet object. If you do it programatically, you can set the sheet as "very hidden", which means it cannot be unhidden through the UI.

ActiveWorkbook.Sheets("Name").Visible = xlSheetVeryHidden 
' or xlSheetHidden or xlSheetVisible

You can also set the Visible property through the properties pane for the worksheet in the VBA IDE (ALT+F11).

How do I POST a x-www-form-urlencoded request using Fetch?

Just did this and UrlSearchParams did the trick Here is my code if it helps someone

import 'url-search-params-polyfill';
const userLogsInOptions = (username, password) => {



// const formData = new FormData();
  const formData = new URLSearchParams();
  formData.append('grant_type', 'password');
  formData.append('client_id', 'entrance-app');
  formData.append('username', username);
  formData.append('password', password);
  return (
    {
      method: 'POST',
      headers: {
        // "Content-Type": "application/json; charset=utf-8",
        "Content-Type": "application/x-www-form-urlencoded",
    },
      body: formData.toString(),
    json: true,
  }
  );
};


const getUserUnlockToken = async (username, password) => {
  const userLoginUri = `${scheme}://${host}/auth/realms/${realm}/protocol/openid-connect/token`;
  const response = await fetch(
    userLoginUri,
    userLogsInOptions(username, password),
  );
  const responseJson = await response.json();
  console.log('acces_token ', responseJson.access_token);
  if (responseJson.error) {
    console.error('error ', responseJson.error);
  }
  console.log('json ', responseJson);
  return responseJson.access_token;
};

What is the difference between Select and Project Operations

PROJECT eliminates columns while SELECT eliminates rows.

Using PHP with Socket.io

If you really want to use PHP as your backend for socket.io ,here are what I found. Two socket.io php server side alternative.

https://github.com/walkor/phpsocket.io

https://github.com/RickySu/phpsocket.io

Exmaple codes for the first repository like this.

use PHPSocketIO\SocketIO;

// listen port 2021 for socket.io client
$io = new SocketIO(2021);
$io->on('connection', function($socket)use($io){
  $socket->on('chat message', function($msg)use($io){
    $io->emit('chat message', $msg);
  });
});

Cycles in family tree software

I guess that you have some value that uniquely identifies a person on which you can base your checks.

This is a tricky one. Assuming you want to keep the structure a tree, I suggest this:

Assume this: A has kids with his own daughter.

A adds himself to the program as A and as B. Once in the role of father, let's call it boyfriend.

Add a is_same_for_out() function which tells the output generating part of your program that all links going to B internally should be going to A on presentation of data.

This will make some extra work for the user, but I guess IT would be relatively easy to implement and maintain.

Building from that, you could work on code synching A and B to avoid inconsistencies.

This solution is surely not perfect, but is a first approach.

Java keytool easy way to add server cert from url/port

Just expose dnozay's answer to a function so that we can import multiple certificates at the same time.

#!/usr/bin/env sh

KEYSTORE_FILE=/path/to/keystore.jks
KEYSTORE_PASS=changeit


import_cert() {
  local HOST=$1
  local PORT=$2

  # get the SSL certificate
  openssl s_client -connect ${HOST}:${PORT} </dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > ${HOST}.cert

  # delete the old alias and then import the new one
  keytool -delete -keystore ${KEYSTORE_FILE} -storepass ${KEYSTORE_PASS} -alias ${HOST} &> /dev/null

  # create a keystore and import certificate
  keytool -import -noprompt -trustcacerts \
      -alias ${HOST} -file ${HOST}.cert \
      -keystore ${KEYSTORE_FILE} -storepass ${KEYSTORE_PASS}

  rm ${HOST}.cert
}

import_cert stackoverflow.com 443
import_cert www.google.com 443
import_cert 172.217.194.104 443 # google

Rotate image with javascript

No need for jQuery and lot's of CSS anymore (Note that some browsers need extra CSS)

Kind of what @Abinthaha posted, but pure JS, without the need of jQuery.

_x000D_
_x000D_
let rotateAngle = 90;_x000D_
_x000D_
function rotate(image) {_x000D_
  image.setAttribute("style", "transform: rotate(" + rotateAngle + "deg)");_x000D_
  rotateAngle = rotateAngle + 90;_x000D_
}
_x000D_
#rotater {_x000D_
  transition: all 0.3s ease;_x000D_
  border: 0.0625em solid black;_x000D_
  border-radius: 3.75em;_x000D_
}
_x000D_
<img id="rotater" onclick="rotate(this)" src="https://upload.wikimedia.org/wikipedia/en/e/e0/Iron_Man_bleeding_edge.jpg"/>
_x000D_
_x000D_
_x000D_

The module was expected to contain an assembly manifest

Check if the manifest is a valid xml file. I had the same problem by doing a DOS copy command at the end of the build, and it turns out that for some reason I can not understand "copy" was adding a strange character (->) at the end of the manifest files. The problem was solved by adding "/b" switch to force binary copy.

Standard Android menu icons, for example refresh

You can get the icons from the android sdk they are in this folder

$android-sdk\platforms\android-xx\data\res

How to fix/convert space indentation in Sublime Text?

Recently I faced a similar problem. I was using the sublime editor. it's not an issue with the code but with the editor.

Below change in the preference settings worked for me.

Sublime Text menu -> Preferences -> Settings: Syntax-Specific:

{
    "tab_size": 4,
    "translate_tabs_to_spaces": true
}

How do I create a round cornered UILabel on the iPhone?

Depending on what exactly you are doing you could make an image and set it as the background programatically.

ActiveXObject in Firefox or Chrome (not IE!)

ActiveX is only supported by IE - the other browsers use a plugin architecture called NPAPI. However, there's a cross-browser plugin framework called Firebreath that you might find useful.

Angular ui-grid dynamically calculate height of the grid

I like Tony approach. It works, but I decided to implement in different way. Here my comments:

1) I did some tests and when using ng-style, Angular evaluates ng-style content, I mean getTableHeight() function more than once. I put a breakpoint into getTableHeight() function to analyze this.

By the way, ui-if was removed. Now you have ng-if build-in.

2) I prefer to write a service like this:

angular.module('angularStart.services').factory('uiGridService', function ($http, $rootScope) {

var factory = {};

factory.getGridHeight = function(gridOptions) {

    var length = gridOptions.data.length;
    var rowHeight = 30; // your row height
    var headerHeight = 40; // your header height
    var filterHeight = 40; // your filter height

    return length * rowHeight + headerHeight + filterHeight + "px";
}
factory.removeUnit = function(value, unit) {

    return value.replace(unit, '');
}
return factory;

});

And then in the controller write the following:

  angular.module('app',['ui.grid']).controller('AppController', ['uiGridConstants', function(uiGridConstants) {

  ...

  // Execute this when you have $scope.gridData loaded...
  $scope.gridHeight = uiGridService.getGridHeight($scope.gridData);

And at the HTML file:

  <div id="grid1" ui-grid="gridData" class="grid" ui-grid-auto-resize style="height: {{gridHeight}}"></div>

When angular applies the style, it only has to look in the $scope.gridHeight variable and not to evaluate a complete function.

3) If you want to calculate dynamically the height of an expandable grid, it is more complicated. In this case, you can set expandableRowHeight property. This fixes the reserved height for each subgrid.

    $scope.gridData = {
        enableSorting: true,
        multiSelect: false,  
        enableRowSelection: true,
        showFooter: false,
        enableFiltering: true,    
        enableSelectAll: false,
        enableRowHeaderSelection: false, 
        enableGridMenu: true,
        noUnselect: true,
        expandableRowTemplate: 'subGrid.html',
        expandableRowHeight: 380,   // 10 rows * 30px + 40px (header) + 40px (filters)
        onRegisterApi: function(gridApi) {

            gridApi.expandable.on.rowExpandedStateChanged($scope, function(row){
                var height = parseInt(uiGridService.removeUnit($scope.jdeNewUserConflictsGridHeight,'px'));
                var changedRowHeight = parseInt(uiGridService.getGridHeight(row.entity.subGridNewUserConflictsGrid, true));

                if (row.isExpanded)
                {
                    height += changedRowHeight;                    
                }
                else
                {
                    height -= changedRowHeight;                    
                }

                $scope.jdeNewUserConflictsGridHeight = height + 'px';
            });
        },
        columnDefs :  [
                { field: 'GridField1', name: 'GridField1', enableFiltering: true }
        ]
    }

How to show particular image as thumbnail while implementing share on Facebook?

Sharing on Facebook: How to Improve Your Results by Customizing the Image, Title, and Text

From the link above. For the best possible share, you'll want to suggest 3 pieces of data in your HTML:

  • Title
  • Short description
  • Image

This accomplished by the following, placed inside the 'head' tag of your HTML:

  • Title: <title>INSERT POST TITLE</title>
  • Image: <meta property=og:image content="http://site.com/YOUR_IMAGE.jpg"/>
  • Description: <meta name=description content="INSERT YOUR SUMMARY TEXT"/>

If you website is static HTML, you'll have to do this for every page using your HTML editor.

If you're using a CMS like Drupal, you can automate a lot of it (see above link). If you use wordpress, you can probably implement something similar using the Drupal example as a guideline. I hope you found these useful.

Finally, you can always manually edit your share posts. See this example with illustrations.

How to programmatically turn off WiFi on Android device?

You need the following permissions in your manifest file:

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

Then you can use the following in your activity class:

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

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

boolean wifiEnabled = wifiManager.isWifiEnabled()

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

Javascript Drag and drop for touch devices

For anyone looking to use this and keep the 'click' functionality (as John Landheer mentions in his comment), you can do it with just a couple of modifications:

Add a couple of globals:

var clickms = 100;
var lastTouchDown = -1;

Then modify the switch statement from the original to this:

var d = new Date();
switch(event.type)
{
    case "touchstart": type = "mousedown"; lastTouchDown = d.getTime(); break;
    case "touchmove": type="mousemove"; lastTouchDown = -1; break;        
    case "touchend": if(lastTouchDown > -1 && (d.getTime() - lastTouchDown) < clickms){lastTouchDown = -1; type="click"; break;} type="mouseup"; break;
    default: return;
}

You may want to adjust 'clickms' to your tastes. Basically it's just watching for a 'touchstart' followed quickly by a 'touchend' to simulate a click.

can't multiply sequence by non-int of type 'float'

In this line:

fund = fund * (1 + 0.01 * growthRates) + depositPerYear

growthRates is a sequence ([3,4,5,0,3]). You can't multiply that sequence by a float (0.1). It looks like what you wanted to put there was i.

Incidentally, i is not a great name for that variable. Consider something more descriptive, like growthRate or rate.

Run Stored Procedure in SQL Developer?

None of these other answers worked for me. Here's what I had to do to run a procedure in SQL Developer 3.2.20.10:

SET serveroutput on;
DECLARE
  testvar varchar(100);
BEGIN
  testvar := 'dude';
  schema.MY_PROC(testvar);
  dbms_output.enable;
  dbms_output.put_line(testvar);
END;

And then you'd have to go check the table for whatever your proc was supposed to do with that passed-in variable -- the output will just confirm that the variable received the value (and theoretically, passed it to the proc).

NOTE (differences with mine vs. others):

  • No : prior to the variable name
  • No putting .package. or .packages. between the schema name and the procedure name
  • No having to put an & in the variable's value.
  • No using print anywhere
  • No using var to declare the variable

All of these problems left me scratching my head for the longest and these answers that have these egregious errors out to be taken out and tarred and feathered.

How to use jQuery in AngularJS

You have to do binding in a directive. Look at this:

angular.module('ng', []).
directive('sliderRange', function($parse, $timeout){
    return {
        restrict: 'A',
        replace: true,
        transclude: false,
        compile: function(element, attrs) {            
            var html = '<div class="slider-range"></div>';
            var slider = $(html);
            element.replaceWith(slider);
            var getterLeft = $parse(attrs.ngModelLeft), setterLeft = getterLeft.assign;
            var getterRight = $parse(attrs.ngModelRight), setterRight = getterRight.assign;

            return function (scope, slider, attrs, controller) {
                var vsLeft = getterLeft(scope), vsRight = getterRight(scope), f = vsLeft || 0, t = vsRight || 10;                        

                var processChange = function() {
                    var vs = slider.slider("values"), f = vs[0], t = vs[1];                                        
                    setterLeft(scope, f);
                    setterRight(scope, t);                    
                }                 
                slider.slider({
                    range: true,
                    min: 0,
                    max: 10,
                    step: 1,
                    change: function() { setTimeout(function () { scope.$apply(processChange); }, 1) }
                }).slider("values", [f, t]);                    
            };            
        }
    };
});

This shows you an example of a slider range, done with jQuery UI. Example usage:

<div slider-range ng-model-left="question.properties.range_from" ng-model-right="question.properties.range_to"></div>

How to edit default dark theme for Visual Studio Code?

Any color theme can be changed in this settings section on VS Code version 1.12 or higher:

 // Overrides colors from the currently selected color theme.
  "workbench.colorCustomizations": {}

See https://code.visualstudio.com/docs/getstarted/themes#_customize-a-color-theme

Available values to edit: https://code.visualstudio.com/docs/getstarted/theme-color-reference

EDIT: To change syntax colors, see here: https://code.visualstudio.com/docs/extensions/themes-snippets-colorizers#_syntax-highlighting-colors and here: https://www.sublimetext.com/docs/3/scope_naming.html

How do I reference tables in Excel using VBA?

In addition to the above, you can do this (where "YourListObjectName" is the name of your table):

Dim LO As ListObject
Set LO = ActiveSheet.ListObjects("YourListObjectName")

But I think that only works if you want to reference a list object that's on the active sheet.

I found your question because I wanted to refer to a list object (a table) on one worksheet that a pivot table on a different worksheet refers to. Since list objects are part of the Worksheets collection, you have to know the name of the worksheet that list object is on in order to refer to it. So to get the name of the worksheet that the list object is on, I got the name of the pivot table's source list object (again, a table) and looped through the worksheets and their list objects until I found the worksheet that contained the list object I was looking for.

Public Sub GetListObjectWorksheet()
' Get the name of the worksheet that contains the data
' that is the pivot table's source data.

    Dim WB As Workbook
    Set WB = ActiveWorkbook

    ' Create a PivotTable object and set it to be
    ' the pivot table in the active cell:
    Dim PT As PivotTable
    Set PT = ActiveCell.PivotTable

    Dim LO As ListObject
    Dim LOWS As Worksheet

    ' Loop through the worksheets and each worksheet's list objects
    ' to find the name of the worksheet that contains the list object
    ' that the pivot table uses as its source data:
    Dim WS As Worksheet
    For Each WS In WB.Worksheets
        ' Loop through the ListObjects in each workshet:
        For Each LO In WS.ListObjects
            ' If the ListObject's name is the name of the pivot table's soure data,
            ' set the LOWS to be the worksheet that contains the list object:
            If LO.Name = PT.SourceData Then
                Set LOWS = WB.Worksheets(LO.Parent.Name)
            End If
        Next LO
    Next WS

    Debug.Print LOWS.Name

End Sub

Maybe someone knows a more direct way.

Comparing mongoose _id and strings

ObjectIDs are objects so if you just compare them with == you're comparing their references. If you want to compare their values you need to use the ObjectID.equals method:

if (results.userId.equals(AnotherMongoDocument._id)) {
    ...
}

Java Long primitive type maximum limit

Long.MAX_VALUE is 9,223,372,036,854,775,807.

If you were executing your function once per nanosecond, it would still take over 292 years to encounter this situation according to this source.

When that happens, it'll just wrap around to Long.MIN_VALUE, or -9,223,372,036,854,775,808 as others have said.

How do I use $rootScope in Angular to store variables?

http://astutejs.blogspot.in/2015/07/angularjs-what-is-rootscope.html

 app.controller('AppCtrl2', function ($scope, $rootScope) {
     $scope.msg = 'SCOPE';
     $rootScope.name = 'ROOT SCOPE';
 });

Warning: A non-numeric value encountered

That's happen usually when you con-cat strings with + sign. In PHP you can make concatenation using dot sign (.) So sometimes I accidentally put + sign between two strings in PHP, and it show me this error, since you can use + sign in numbers only.

HTML5 form required attribute. Set custom validation message?

Okay, oninvalid works well but it shows error even if user entered valid data. So I have used below to tackle it, hope it will work for you as well,

oninvalid="this.setCustomValidity('Your custom message.')" onkeyup="setCustomValidity('')"

Caching a jquery ajax response in javascript/browser

Old question, but my solution is a bit different.

I was writing a single page web app that was constantly making ajax calls triggered by the user, and to make it even more difficult it required libraries that used methods other than jquery (like dojo, native xhr, etc). I wrote a plugin for one of my own libraries to cache ajax requests as efficiently as possible in a way that would work in all major browsers, regardless of which libraries were being used to make the ajax call.

The solution uses jSQL (written by me - a client-side persistent SQL implementation written in javascript which uses indexeddb and other dom storage methods), and is bundled with another library called XHRCreep (written by me) which is a complete re-write of the native XHR object.

To implement all you need to do is include the plugin in your page, which is here.

There are two options:

jSQL.xhrCache.max_time = 60;

Set the maximum age in minutes. any cached responses that are older than this are re-requested. Default is 1 hour.

jSQL.xhrCache.logging = true;

When set to true, mock XHR calls will be shown in the console for debugging.

You can clear the cache on any given page via

jSQL.tables = {}; jSQL.persist();

Better way to cast object to int

Maybe Convert.ToInt32.

Watch out for exception, in both cases.

SQL Server: Make all UPPER case to Proper Case/Title Case

A slight modification to @Galwegian's answer - which turns e.g. St Elizabeth's into St Elizabeth'S.

This modification keeps apostrophe-s as lowercase where the s comes at the end of the string provided or the s is followed by a space (and only in those circumstances).

create function properCase(@text as varchar(8000))
returns varchar(8000)
as
begin
    declare @reset int;
    declare @ret varchar(8000);
    declare @i int;
    declare @c char(1);
    declare @d char(1);

    if @text is null
    return null;

    select @reset = 1, @i = 1, @ret = '';

    while (@i <= len(@text))
    select
        @c = substring(@text, @i, 1),
        @d = substring(@text, @i+1, 1),
        @ret = @ret + case when @reset = 1 or (@reset=-1 and @c!='s') or (@reset=-1 and @c='s' and @d!=' ') then upper(@c) else lower(@c) end,
        @reset = case when @c like '[a-za-z]' then 0 when @c='''' then -1 else 1 end,
        @i = @i + 1
    return @ret
end

It turns:

  • st elizabeth's into St Elizabeth's
  • o'keefe into O'Keefe
  • o'sullivan into O'Sullivan

Others' comments that different solutions are preferable for non-English input remain the case.