Programs & Examples On #Mergetool

Git: How configure KDiff3 as merge tool and diff tool

Just to extend the @Joseph's answer:

After applying these commands your global .gitconfig file will have the following lines (to speed up the process you can just copy them in the file):

[merge]
    tool = kdiff3
[mergetool "kdiff3"]
    path = C:/Program Files/KDiff3/kdiff3.exe
    trustExitCode = false
[diff]
    guitool = kdiff3
[difftool "kdiff3"]
    path = C:/Program Files/KDiff3/kdiff3.exe
    trustExitCode = false

Are there any disadvantages to always using nvarchar(MAX)?

The only problem I found was that we develop our applications on SQL Server 2005, and in one instance, we have to support SQL Server 2000. I just learned, the hard way that SQL Server 2000 doesn't like the MAX option for varchar or nvarchar.

Add image in pdf using jspdf

This worked for me in Angular 2:

var img = new Image()
img.src = 'assets/sample.png'
pdf.addImage(img, 'png', 10, 78, 12, 15)

jsPDF version 1.5.3

assets directory is in src directory of the Angular project root

Type definition in object literal in TypeScript

In TypeScript if we are declaring object then we'd use the following syntax:

[access modifier] variable name : { /* structure of object */ }

For example:

private Object:{ Key1: string, Key2: number }

When should static_cast, dynamic_cast, const_cast and reinterpret_cast be used?

Does this answer your question?

I have never used reinterpret_cast, and wonder whether running into a case that needs it isn't a smell of bad design. In the code base I work on dynamic_cast is used a lot. The difference with static_cast is that a dynamic_cast does runtime checking which may (safer) or may not (more overhead) be what you want (see msdn).

IIS URL Rewrite and Web.config

1) Your existing web.config: you have declared rewrite map .. but have not created any rules that will use it. RewriteMap on its' own does absolutely nothing.

2) Below is how you can do it (it does not utilise rewrite maps -- rules only, which is fine for small amount of rewrites/redirects):

This rule will do SINGLE EXACT rewrite (internal redirect) /page to /page.html. URL in browser will remain unchanged.

<system.webServer>
    <rewrite>
        <rules>
            <rule name="SpecificRewrite" stopProcessing="true">
                <match url="^page$" />
                <action type="Rewrite" url="/page.html" />
            </rule>
        </rules>
    </rewrite>
</system.webServer>

This rule #2 will do the same as above, but will do 301 redirect (Permanent Redirect) where URL will change in browser.

<system.webServer>
    <rewrite>
        <rules>
            <rule name="SpecificRedirect" stopProcessing="true">
                <match url="^page$" />
                <action type="Redirect" url="/page.html" />
            </rule>
        </rules>
    </rewrite>
</system.webServer>

Rule #3 will attempt to execute such rewrite for ANY URL if there are such file with .html extension (i.e. for /page it will check if /page.html exists, and if it does then rewrite occurs):

<system.webServer>
    <rewrite>
        <rules>
            <rule name="DynamicRewrite" stopProcessing="true">
                <match url="(.*)" />
                <conditions>
                    <add input="{REQUEST_FILENAME}\.html" matchType="IsFile" />
                </conditions>
                <action type="Rewrite" url="/{R:1}.html" />
            </rule>
        </rules>
    </rewrite>
</system.webServer>

Caused By: java.lang.NoClassDefFoundError: org/apache/log4j/Logger

Based on the stacktrace, an intuit class com.intuit.ipp.aggcat.util.SAML2AssertionGenerator needs a saml jar on the classpath.

A saml class org.opensaml.xml.XMLConfigurator needs on it's turn log4j, which is inside the WAR but cannot find it.

One explanation for this is that the class XMLConfigurator that needs log4j was found not inside the WAR but on a downstream classloader. could a saml jar be missing from the WAR?

The class XMLConfigurator that needs log4j cannot find it at the level of the classloader that loaded it, and the log4j version on the WAR is not visible on that particular classloader.

In order to troubleshoot this, a way is to add this before the oauth call:

System.out.println("all versions of log4j Logger: " + getClass().getClassLoader().getResources("org/apache/log4j/Logger.class") );

System.out.println("all versions of XMLConfigurator: " + getClass().getClassLoader().getResources("org/opensaml/xml/XMLConfigurator.class") );

System.out.println("all versions of XMLConfigurator visible from the classloader of the OAuthAuthorizer class: " + OAuthAuthorizer.class.getClassLoader().getResources("org/opensaml/xml/XMLConfigurator.class") );

System.out.println("all versions of log4j visible from the classloader of the OAuthAuthorizer class: " + OAuthAuthorizer.class.getClassloader().getResources("org/apache/log4j/Logger.class") );

Also if you are using Java 7, have a look at jHades, it's a tool I made to help troubleshooting these type of problems.

In order to see what is going on, could you post the results of the classpath queries above, for which container is this happening, tomcat, jetty? It would be better to put the full stacktrace with all the caused by's in pastebin, just in case.

C# Example of AES256 encryption using System.Security.Cryptography.Aes

public class AesCryptoService
{
    private static byte[] Key = Encoding.ASCII.GetBytes(@"qwr{@^h`h&_`50/ja9!'dcmh3!uw<&=?");
    private static byte[] IV = Encoding.ASCII.GetBytes(@"9/\~V).A,lY&=t2b");


    public static string EncryptStringToBytes_Aes(string plainText)
    {
        if (plainText == null || plainText.Length <= 0)
            throw new ArgumentNullException("plainText");
        if (Key == null || Key.Length <= 0)
            throw new ArgumentNullException("Key");
        if (IV == null || IV.Length <= 0)
            throw new ArgumentNullException("IV");
        byte[] encrypted;


        using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
        {
            aesAlg.Key = Key;
            aesAlg.IV = IV;
            aesAlg.Mode = CipherMode.CBC;
            aesAlg.Padding = PaddingMode.PKCS7;

            ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

            using (MemoryStream msEncrypt = new MemoryStream())
            {
                using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                {
                    using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                    {
                        swEncrypt.Write(plainText);
                    }
                    encrypted = msEncrypt.ToArray();
                }
            }
        }
        
        return Convert.ToBase64String(encrypted);
    }


    
    public static string DecryptStringFromBytes_Aes(string Text)
    {
        if (Text == null || Text.Length <= 0)
            throw new ArgumentNullException("cipherText");
        if (Key == null || Key.Length <= 0)
            throw new ArgumentNullException("Key");
        if (IV == null || IV.Length <= 0)
            throw new ArgumentNullException("IV");

        string plaintext = null;
        byte[] cipherText = Convert.FromBase64String(Text.Replace(' ', '+'));

        using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
        {
            aesAlg.Key = Key;
            aesAlg.IV = IV;
            aesAlg.Mode = CipherMode.CBC;
            aesAlg.Padding = PaddingMode.PKCS7;


            ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

            using (MemoryStream msDecrypt = new MemoryStream(cipherText))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {
                        plaintext = srDecrypt.ReadToEnd();
                    }
                }
            }

        }

        return plaintext;
    }
}

Two values from one input in python?

Two inputs separated by space:

x,y=input().split()

Execute Python script via crontab

Put your script in a file foo.py starting with

#!/usr/bin/python

Then give execute permission to that script using

chmod a+x foo.py

and use the full path of your foo.py file in your crontab.

See documentation of execve(2) which is handling the shebang.

How to remove a package from Laravel using composer?

Got it working... The steps to remove a package from Laravel are:

  1. Remove declaration from composer.json (in "require" section)
  2. Remove Service Provider from config/app.php (reference in "providers" array)
  3. Remove any Class Aliases from config/app.php
  4. Remove any references to the package from your code :-)
  5. Run composer update vendor/package-name. This will remove the package folder from the vendor folder and will rebuild the composer autoloading map.
  6. Manually delete the published files (read the comment by zwacky)

It will remove the package folder from Vendor folder

Git error: src refspec master does not match any error: failed to push some refs

One classic root cause for this message is:

  • when the repo has been initialized (git init lis4368/assignments),
  • but no commit has ever been made

Ie, if you don't have added and committed at least once, there won't be a local master branch to push to.

Try first to create a commit:

  • either by adding (git add .) then git commit -m "first commit"
    (assuming you have the right files in place to add to the index)
  • or by create a first empty commit: git commit --allow-empty -m "Initial empty commit"

And then try git push -u origin master again.

See "Why do I need to explicitly push a new branch?" for more.

Do checkbox inputs only post data if they're checked?

From HTML 4 spec, which should be consistent across almost all browsers:

http://www.w3.org/TR/html401/interact/forms.html#checkbox

Checkboxes (and radio buttons) are on/off switches that may be toggled by the user. A switch is "on" when the control element's checked attribute is set. When a form is submitted, only "on" checkbox controls can become successful.

Successful is defined as follows:

A successful control is "valid" for submission. Every successful control has its control name paired with its current value as part of the submitted form data set. A successful control must be defined within a FORM element and must have a control name.

Spring-boot default profile for integration tests

If you use maven, you can add this in pom.xml:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-failsafe-plugin</artifactId>
            <configuration>
                <argLine>-Dspring.profiles.active=test</argLine>
            </configuration>
        </plugin>
        ...

Then, maven should run your integration tests (*IT.java) using this arugument, and also IntelliJ will start with this profile activated - so you can then specify all properties inside

application-test.yml

and you should not need "-default" properties.

Java maximum memory on Windows XP

The JVM needs contiguous memory and depending on what else is running, what was running before, and how windows has managed memory you may be able to get up to 1.4GB of contiguous memory. I think 64bit Windows will allow larger heaps.

How to remove a virtualenv created by "pipenv run"

You can run the pipenv command with the --rm option as in:

pipenv --rm

This will remove the virtualenv created for you under ~/.virtualenvs

See https://pipenv.kennethreitz.org/en/latest/cli/#cmdoption-pipenv-rm

this in equals method

this refers to the current instance of the class (object) your equals-method belongs to. When you test this against an object, the testing method (which is equals(Object obj) in your case) will check wether or not the object is equal to the current instance (referred to as this).

An example:

Object obj = this; this.equals(obj); //true   Object obj = this; new Object().equals(obj); //false 

Determining Referer in PHP

Using $_SERVER['HTTP_REFERER']

The address of the page (if any) which referred the user agent to the current page. This is set by the user agent. Not all user agents will set this, and some provide the ability to modify HTTP_REFERER as a feature. In short, it cannot really be trusted.

if (!empty($_SERVER['HTTP_REFERER'])) {
    header("Location: " . $_SERVER['HTTP_REFERER']);
} else {
    header("Location: index.php");
}
exit;

.attr("disabled", "disabled") issue

Thank you all for your contribution! I found the problem:

ITS A FIREBUG BUG !!!

My code works. I have asked the PHP Dev to change the input types hidden in to input type text. The disabled feature works. But the firebug console does not update this status!

you can test out this firebug bug by your self here http://jsbin.com/uneti3/3#. Thx to aSeptik for the example page.

update: 2. June 2012: Firebug in FF11 still has this bug.

Sleep function in Windows, using C

MSDN: Header: Winbase.h (include Windows.h)

How to use the CancellationToken property?

You can use ThrowIfCancellationRequested without handling the exception!

The use of ThrowIfCancellationRequested is meant to be used from within a Task (not a Thread). When used within a Task, you do not have to handle the exception yourself (and get the Unhandled Exception error). It will result in leaving the Task, and the Task.IsCancelled property will be True. No exception handling needed.

In your specific case, change the Thread to a Task.

Task t = null;
try
{
    t = Task.Run(() => Work(cancelSource.Token), cancelSource.Token);
}

if (t.IsCancelled)
{
    Console.WriteLine("Canceled!");
}

Xcode - Warning: Implicit declaration of function is invalid in C99

should call the function properly; like- Fibonacci:input

Simplest JQuery validation rules example

$("#commentForm").validate({
    rules: {
     cname : { required : true, minlength: 2 }
    }
});

Should be something like that, I've just typed this up in the editor here so might be a syntax error or two, but you should be able to follow the pattern and the documentation

How to access pandas groupby dataframe by key

I was looking for a way to sample a few members of the GroupBy obj - had to address the posted question to get this done.

create groupby object based on some_key column

grouped = df.groupby('some_key')

pick N dataframes and grab their indices

sampled_df_i  = random.sample(grouped.indices, N)

grab the groups

df_list  = map(lambda df_i: grouped.get_group(df_i), sampled_df_i)

optionally - turn it all back into a single dataframe object

sampled_df = pd.concat(df_list, axis=0, join='outer')

Auto increment in phpmyadmin

@AmitKB, Your procedure is correct. Although this error

Query error: #1075 - Incorrect table definition; there can be only one auto column and it must be defined as a key

can be solved by first marking the field as key(using the key icon with label primary),unless you have other key then it may not work.

How can I install a package with go get?

First, we need GOPATH

The $GOPATH is a folder (or set of folders) specified by its environment variable. We must notice that this is not the $GOROOT directory where Go is installed.

export GOPATH=$HOME/gocode
export PATH=$PATH:$GOPATH/bin

We used ~/gocode path in our computer to store the source of our application and its dependencies. The GOPATH directory will also store the binaries of their packages.

Then check Go env

You system must have $GOPATH and $GOROOT, below is my Env:

GOARCH="amd64"
GOBIN=""
GOCHAR="6"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/elpsstu/gocode"
GORACE=""
GOROOT="/home/pravin/go"
GOTOOLDIR="/home/pravin/go/pkg/tool/linux_amd64"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0"
CXX="g++"
CGO_ENABLED="1"

Now, you run download go package:

go get [-d] [-f] [-fix] [-t] [-u] [build flags] [packages]

Get downloads and installs the packages named by the import paths, along with their dependencies. For more details you can look here.

How to create dynamic href in react render function?

In addition to Felix's answer,

href={`/posts/${posts.id}`}

would work well too. This is nice because it's all in one string.

How do I remove repeated elements from ArrayList?

If you want to preserve your Order then it is best to use LinkedHashSet. Because if you want to pass this List to an Insert Query by Iterating it, the order would be preserved.

Try this

LinkedHashSet link=new LinkedHashSet();
List listOfValues=new ArrayList();
listOfValues.add(link);

This conversion will be very helpful when you want to return a List but not a Set.

Oracle DB: How can I write query ignoring case?

Also don't forget the obvious, does the data in the tables need to have case? You could only insert rows already in lower case (or convert the existing DB rows to lower case) and be done with it right from the start.

How can I exit from a javascript function?

You should use return as in:

function refreshGrid(entity) {
  var store = window.localStorage;
  var partitionKey;
  if (exit) {
    return;
  }

WAMP Server ERROR "Forbidden You don't have permission to access /phpmyadmin/ on this server."

In your apache config file (../bin/apachex.y.z/cong/httpd.conf)

Just change

< Directory "c:/wamp/www/" > ...
...

"Require local" ===> "Require all granted"
< /Directory >

This allows other pc's to access (to read) your web folder.

Can't bind to 'ngIf' since it isn't a known property of 'div'

Instead of [ngIf] you should use *ngIf like this:

<div *ngIf="isAuth" id="sidebar">

Powershell: A positional parameter cannot be found that accepts argument "xxx"

In my case I had tried to make code more readable by putting:

"LONGTEXTSTRING " +
"LONGTEXTSTRING" +
"LONGTEXTSTRING"

Once I changed it to

LONGTEXTSTRING LONGTEXTSTRING LONGTEXTSTRING 

Then it worked

The source was not found, but some or all event logs could not be searched

If you are performing a new install of the SenseNet TaskManagement website on IIS (from source code, not WebPI), you will get this message, usually related to SignalR communication. As @nicole-caliniou points out, it is due to a key search in the Registry that fails.

To solve this for SenseNet TaskManagement v1.1.0, first find the registry key name in the web.config file. By default it is "SnTaskWeb".

 <appSettings>
   <add key="LogSourceName" value="SnTaskWeb" />

Open the registry editor, regedit.exe, and navigate to HKLM\SYSTEM\CurrentControlSet\Services\EventLog\SnTask. Right-click on SnTask and select New Key, and name the key SnTaskWeb for the configuration shown above. Then right-click on the SnTaskWeb element and select New Expandable String Value. The name should be EventMessageFile and the value data should be C:\Windows\Microsoft.NET\Framework\v4.0.30319\EventLogMessages.dll.

Keywords: signalr, sensenet, regedit, permissions

How to programmatically connect a client to a WCF service?

You can also do what the "Service Reference" generated code does

public class ServiceXClient : ClientBase<IServiceX>, IServiceX
{
    public ServiceXClient() { }

    public ServiceXClient(string endpointConfigurationName) :
        base(endpointConfigurationName) { }

    public ServiceXClient(string endpointConfigurationName, string remoteAddress) :
        base(endpointConfigurationName, remoteAddress) { }

    public ServiceXClient(string endpointConfigurationName, EndpointAddress remoteAddress) :
        base(endpointConfigurationName, remoteAddress) { }

    public ServiceXClient(Binding binding, EndpointAddress remoteAddress) :
        base(binding, remoteAddress) { }

    public bool ServiceXWork(string data, string otherParam)
    {
        return base.Channel.ServiceXWork(data, otherParam);
    }
}

Where IServiceX is your WCF Service Contract

Then your client code:

var client = new ServiceXClient(new WSHttpBinding(SecurityMode.None), new EndpointAddress("http://localhost:911"));
client.ServiceXWork("data param", "otherParam param");

MVC 4 Edit modal form using Bootstrap

You should use partial views. I use the following approach:

Use a view model so you're not passing your domain models to your views:

public class EditPersonViewModel
{
    public int Id { get; set; }   // this is only used to retrieve record from Db
    public string Name { get; set; }
    public string Age { get; set; }
}

In your PersonController:

[HttpGet] // this action result returns the partial containing the modal
public ActionResult EditPerson(int id)
{  
    var viewModel = new EditPersonViewModel();
    viewModel.Id = id;
    return PartialView("_EditPersonPartial", viewModel);
}

[HttpPost] // this action takes the viewModel from the modal
public ActionResult EditPerson(EditPersonViewModel viewModel)
{
    if (ModelState.IsValid)
    {
        var toUpdate = personRepo.Find(viewModel.Id);
        toUpdate.Name = viewModel.Name;
        toUpdate.Age = viewModel.Age;
        personRepo.InsertOrUpdate(toUpdate);
        personRepo.Save();
        return View("Index");
    }
}

Next create a partial view called _EditPersonPartial. This contains the modal header, body and footer. It also contains the Ajax form. It's strongly typed and takes in our view model.

@model Namespace.ViewModels.EditPersonViewModel
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
    <h3 id="myModalLabel">Edit group member</h3>
</div>
<div>
@using (Ajax.BeginForm("EditPerson", "Person", FormMethod.Post,
                    new AjaxOptions
                    {
                        InsertionMode = InsertionMode.Replace,
                        HttpMethod = "POST",
                        UpdateTargetId = "list-of-people"
                    }))
{
    @Html.ValidationSummary()
    @Html.AntiForgeryToken()
    <div class="modal-body">
        @Html.Bootstrap().ControlGroup().TextBoxFor(x => x.Name)
        @Html.Bootstrap().ControlGroup().TextBoxFor(x => x.Age)
    </div>
    <div class="modal-footer">
        <button class="btn btn-inverse" type="submit">Save</button>
    </div>
}

Now somewhere in your application, say another partial _peoplePartial.cshtml etc:

<div>
   @foreach(var person in Model.People)
    {
        <button class="btn btn-primary edit-person" data-id="@person.PersonId">Edit</button>
    }
</div>
// this is the modal definition
<div class="modal hide fade in" id="edit-person">
    <div id="edit-person-container"></div>
</div>

    <script type="text/javascript">
    $(document).ready(function () {
        $('.edit-person').click(function () {
            var url = "/Person/EditPerson"; // the url to the controller
            var id = $(this).attr('data-id'); // the id that's given to each button in the list
            $.get(url + '/' + id, function (data) {
                $('#edit-person-container').html(data);
                $('#edit-person').modal('show');
            });
        });
     });
   </script>

How to convert a full date to a short date in javascript?

var d = new Date("Wed Mar 25 2015 05:30:00 GMT+0530 (India Standard Time)"); 
document.getElementById("demo").innerHTML = d.toLocaleDateString();

How to run a command in the background on Windows?

I believe the command you are looking for is start /b *command*

For unix, nohup represents 'no hangup', which is slightly different than a background job (which would be *command* &. I believe that the above command should be similar to a background job for windows.

What are the proper permissions for an upload folder with PHP/Apache?

I will add that if you are using SELinux that you need to make sure the type context is tmp_t You can accomplish this by using the chcon utility

chcon -t tmp_t uploads

How to select the comparison of two columns as one column in Oracle

select column1, coulumn2, case when colum1=column2 then 'true' else 'false' end from table;

HTH

$.ajax( type: "POST" POST method to php

You need to use data: {title: title} to POST it correctly.

In the PHP code you need to echo the value instead of returning it.

Rearrange columns using cut

You can use Perl for that:

perl -ane 'print "$F[1] $F[0]\n"' < file.txt
  • -e option means execute the command after it
  • -n means read line by line (open the file, in this case STDOUT, and loop over lines)
  • -a means split such lines to a vector called @F ("F" - like Field). Perl indexes vectors starting from 0 unlike cut which indexes fields starting form 1.
  • You can add -F pattern (with no space between -F and pattern) to use pattern as a field separator when reading the file instead of the default whitespace

The advantage of running perl is that (if you know Perl) you can do much more computation on F than rearranging columns.

Regex to test if string begins with http:// or https://

(http|https)?:\/\/(\S+)

This works for me

Not a regex specialist, but i will try to explain the awnser.

(http|https) : Parenthesis indicates a capture group, "I" a OR statement.

\/\/ : "\" allows special characters, such as "/"

(\S+) : Anything that is not whitespace until the next whitespace

How do I fill arrays in Java?

Arrays.fill(). The method is overloaded for different data types, and there is even a variation that fills only a specified range of indices.

How to encode URL to avoid special characters in Java?

If you don't want to do it manually use Apache Commons - Codec library. The class you are looking at is: org.apache.commons.codec.net.URLCodec

String final url = "http://www.google.com?...."
String final urlSafe = org.apache.commons.codec.net.URLCodec.encode(url);

How do I create a master branch in a bare Git repository?

You don't need to use a second repository - you can do commands like git checkout and git commit on a bare repository, if only you supply a dummy work directory using the --work-tree option.

Prepare a dummy directory:

$ rm -rf /tmp/empty_directory
$ mkdir  /tmp/empty_directory

Create the master branch without a parent (works even on a completely empty repo):

$ cd your-bare-repository.git

$ git checkout --work-tree=/tmp/empty_directory --orphan master
Switched to a new branch 'master'                  <--- abort if "master" already exists

Create a commit (it can be a message-only, without adding any files, because what you need is simply having at least one commit):

$ git commit -m "Initial commit" --allow-empty --work-tree=/tmp/empty_directory 

$ git branch
* master

Clean up the directory, it is still empty.

$ rmdir  /tmp/empty_directory

Tested on git 1.9.1. (Specifically for OP, the posh-git is just a PowerShell wrapper for standard git.)

Where to put default parameter value in C++?

C++ places the default parameter logic in the calling side, this means that if the default value expression cannot be computed from the calling place, then the default value cannot be used.

Other compilation units normally just include the declaration so default value expressions placed in the definition can be used only in the defining compilation unit itself (and after the definition, i.e. after the compiler sees the default value expressions).

The most useful place is in the declaration (.h) so that all users will see it.

Some people like to add the default value expressions in the implementation too (as a comment):

void foo(int x = 42,
         int y = 21);

void foo(int x /* = 42 */,
         int y /* = 21 */)
{
   ...
}

However, this means duplication and will add the possibility of having the comment out of sync with the code (what's worse than uncommented code? code with misleading comments!).

Count number of objects in list

I spent ages trying to figure this out but it is simple! You can use length(·). length(mylist) will tell you the number of objects mylist contains.

... and just realised someone had already answered this- sorry!

Best way to get identity of inserted row?

I'm saying the same thing as the other guys, so everyone's correct, I'm just trying to make it more clear.

@@IDENTITY returns the id of the last thing that was inserted by your client's connection to the database.
Most of the time this works fine, but sometimes a trigger will go and insert a new row that you don't know about, and you'll get the ID from this new row, instead of the one you want

SCOPE_IDENTITY() solves this problem. It returns the id of the last thing that you inserted in the SQL code you sent to the database. If triggers go and create extra rows, they won't cause the wrong value to get returned. Hooray

IDENT_CURRENT returns the last ID that was inserted by anyone. If some other app happens to insert another row at an unforunate time, you'll get the ID of that row instead of your one.

If you want to play it safe, always use SCOPE_IDENTITY(). If you stick with @@IDENTITY and someone decides to add a trigger later on, all your code will break.

What is Bootstrap?

Bootstrap is the world’s most popular and widely used open-source framework for developing with HTML, CSS, and JS. It is a front end framework of HTML. Bootstrap helps in building responsive websites or web applications and a 12-column grid system that helps dynamically adjust the website to a suitable screen resolution. The current version of bootstrap is 4.3.1 and the bootstrap team has also officially announced Bootstrap 5 version and changes like removing jquery from bootstrap. Some of the crucial reasons why bootstrap framework is most preferable are

  • It is easy to use

  • Bootstrap has a big community support

  • Customizations can be done easily

  • It increases development speed

  • Responsiveness

    For more details, you can check the official website: https://getbootstrap.com/

Source: https://vmokshagroup.com/blog/bootstrap-advantages/

org.hibernate.MappingException: Unknown entity

use below line of code in the case of spring boot applications.

@EntityScan(basePackageClasses=YourClassName.class)

Current date without time

Try this:

   var mydtn = DateTime.Today;
   var myDt = mydtn.Date;return myDt.ToString("d", CultureInfo.GetCultureInfo("en-US"));

Can't open and lock privilege tables: Table 'mysql.user' doesn't exist

mysqld --initialize to initialize the data directory then mysqld &

If you had already launched mysqld& without mysqld --initialize you might have to delete all files in your data directory

You can also modify /etc/my.cnf to add a custom path to your data directory like this :

[mysqld]
...  
datadir=/path/to/directory

Convert integer to binary in C#

Your example has an integer expressed as a string. Let's say your integer was actually an integer, and you want to take the integer and convert it to a binary string.

int value = 8;
string binary = Convert.ToString(value, 2);

Which returns 1000.

CSS Box Shadow - Top and Bottom Only

So this is my first answer here, and because I needed something similar I did with pseudo elements for 2 inner shadows, and an extra DIV for an upper outer shadow. Don't know if this is the best solutions but maybe it will help someone.

HTML

<div class="shadow-block">
    <div class="shadow"></div>
    <div class="overlay">
        <div class="overlay-inner">
            content here
        </div>
    </div>
</div>

CSS

.overlay {
    background: #f7f7f4;
    height: 185px;
    overflow: hidden;
    position: relative;
    width: 100%; 
}

.overlay:before {
    border-radius: 50% 50% 50% 50%;
    box-shadow: 0 0 50px 2px rgba(1, 1, 1, 0.6);
    content: " ";
    display: block;
    margin: 0 auto;
    width: 80%;
}

.overlay:after {
    border-radius: 50% 50% 50% 50%;
    box-shadow: 0 0 70px 5px rgba(1, 1, 1, 0.5);
    content: "-";
    display: block;
    margin: 0 auto;
    position: absolute;
    bottom: -65px;
    left: -50%;
    right: -50%;
    width: 80%;
}

.shadow {
    position: relative;
    width:100%;
    height:8px;
    margin: 0 0 -22px 0;
    -webkit-box-shadow: 0px 0px 50px 3px rgba(1, 1, 1, 0.6);
    box-shadow: 0px 0px 50px 3px rgba(1, 1, 1, 0.6);
    border-radius: 50%;
}

The program can’t start because MSVCR71.dll is missing from your computer. Try reinstalling the program to fix this program

Based on this page:

  • Run regedit (remember to run it as the administrator)
  • Expand HKEY_LOCAL_MACHINE
  • Expand SOFTWARE
  • Expand Microsoft
  • Expand Windows
  • Expand CurrentVersion
  • Expand App Paths
  • At App Paths, add a new KEY called sqldeveloper.exe
  • Expand sqldeveloper.exe
  • Modify the (DEFAULT) value to the full pathway to the sqldeveloper executable (See example below step 11)
  • Create a new STRING VALUE called PATH and set it value to the sqldeveloper pathway + \jdk\jre\bin

C# Syntax - Example of a Lambda Expression - ForEach() over Generic List

The above could also be written with less code as:

new List<SomeType>(items).ForEach(
    i => Console.WriteLine(i)
);

This creates a generic list and populates it with the IEnumerable and then calls the list objects ForEach.

How to find files recursively by file type and copy them to a directory while in ssh?

Paul Dardeau answer is perfect, the only thing is, what if all the files inside those folders are not PDF files and you want to grab it all no matter the extension. Well just change it to

find . -name "*.*" -type f -exec cp {} ./pdfsfolder \;

Just to sum up!

Insert ellipsis (...) into HTML tag if content too wide

Well, one simple solution, that doesn't quite add the "...", but does prevent the <h2> from breaking into two lines would be to add this bit of css:

h2 {
    height:some_height_in_px; /* this is the height of the line */
    overflow:hidden; /* so that the second (or third, fourth, etc.)
                        line is not visible */
}

I gave it some more thought, and I came up with this solution, you have to wrap the textual contents of your h2 tag with another tag (e.g. a span) (or alternatively wrap the h2s with something that has the given height) and then you can use this sort of javascript to filter out the unneeded words:

var elems = document.getElementById('conainter_of_h2s').
                     getElementsByTagName('h2');

    for ( var i = 0, l = elems.length; i < l; i++) {
        var span = elems.item(i).getElementsByTagName('span')[0];
        if ( span.offsetHeight > elems.item(i).offsetHeight ) {
            var text_arr = span.innerHTML.split(' ');
            for ( var j = text_arr.length - 1; j>0 ; j--) {
                delete text_arr[j];
                span.innerHTML = text_arr.join(' ') + '...';
                if ( span.offsetHeight <= 
                                        elems.item(i).offsetHeight ){
                    break;
                }
            }
        }
    }

Responsive Google Map?

in the iframe tag, you can easily add width='100%' instead of the preset value giving to you by the map

like this:

 <iframe src="https://www.google.com/maps/embed?anyLocation" width="100%" height="400" frameborder="0" style="border:0;" allowfullscreen=""></iframe>

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required?

I've searched and tried different things for hours.. To summarize, I had to take into consideration the following points:

  1. Use smtp.gmail.com instead of smtp.google.com
  2. Use port 587
  3. Set client.UseDefaultCredentials = false; before setting credentials
  4. Turn on the Access for less secure apps
  5. Set client.EnableSsl = true;

If these steps didn't help, check this answer.
Perhaps, you can find something useful on this System.Net.Mail FAQ too.

Vertical align middle with Bootstrap responsive grid

Add !important rule to display: table of your .v-center class.

.v-center {
    display:table !important;
    border:2px solid gray;
    height:300px;
}

Your display property is being overridden by bootstrap to display: block.

Example

"&" meaning after variable type

It means you're passing the variable by reference.

In fact, in a declaration of a type, it means reference, just like:

int x = 42;
int& y = x;

declares a reference to x, called y.

Apache: Restrict access to specific source IP inside virtual host

The mod_authz_host directives need to be inside a <Location> or <Directory> block but I've used the former within <VirtualHost> like so for Apache 2.2:

<VirtualHost *:8080>
    <Location />
    Order deny,allow
    Deny from all
    Allow from 127.0.0.1
    </Location>

    ...
</VirtualHost>

Reference: https://askubuntu.com/questions/262981/how-to-install-mod-authz-host-in-apache

get all keys set in memcached

Bash

To get list of keys in Bash, follow the these steps.

First, define the following wrapper function to make it simple to use (copy and paste into shell):

function memcmd() {
  exec {memcache}<>/dev/tcp/localhost/11211
  printf "%s\n%s\n" "$*" quit >&${memcache}
  cat <&${memcache}
}

Memcached 1.4.31 and above

You can use lru_crawler metadump all command to dump (most of) the metadata for (all of) the items in the cache.

As opposed to cachedump, it does not cause severe performance problems and has no limits on the amount of keys that can be dumped.

Example command by using the previously defined function:

memcmd lru_crawler metadump all

See: ReleaseNotes1431.


Memcached 1.4.30 and below

Get list of slabs by using items statistics command, e.g.:

memcmd stats items

For each slub class, you can get list of items by specifying slub id along with limit number (0 - unlimited):

memcmd stats cachedump 1 0
memcmd stats cachedump 2 0
memcmd stats cachedump 3 0
memcmd stats cachedump 4 0
...

Note: You need to do this for each memcached server.

To list all the keys from all stubs, here is the one-liner (per one server):

for id in $(memcmd stats items | grep -o ":[0-9]\+:" | tr -d : | sort -nu); do
    memcmd stats cachedump $id 0
done

Note: The above command could cause severe performance problems while accessing the items, so it's not advised to run on live.


Notes:

stats cachedump only dumps the HOT_LRU (IIRC?), which is managed by a background thread as activity happens. This means under a new enough version which the 2Q algo enabled, you'll get snapshot views of what's in just one of the LRU's.

If you want to view everything, lru_crawler metadump 1 (or lru_crawler metadump all) is the new mostly-officially-supported method that will asynchronously dump as many keys as you want. you'll get them out of order but it hits all LRU's, and unless you're deleting/replacing items multiple runs should yield the same results.

Source: GH-405.


Related:

Inserting into Oracle and retrieving the generated sequence ID

You can use the below statement to get the inserted Id to a variable-like thing.

INSERT INTO  YOUR_TABLE(ID) VALUES ('10') returning ID into :Inserted_Value;

Now you can retrieve the value using the below statement

SELECT :Inserted_Value FROM DUAL;

How do you find the current user in a Windows environment?

%USERNAME% will get you the username of the currently running process. Depending on how you are running your batch file, this is not necessarily the same as the name of the current user. For example, you might be running your batch file through a scheduled task, from a service, etc.

Here is a more sure way of getting the username of the currently logged on user by scraping the name of the user that started the explorer.exe task:

for /f "TOKENS=1,2,*" %%a in ('tasklist /FI "IMAGENAME eq explorer.exe" /FO LIST /V') do if /i "%%a %%b"=="User Name:" set _currdomain_user=%%c
for /f "TOKENS=1,2 DELIMS=\" %%a in ("%_currdomain_user%") do set _currdomain=%%a & set _curruser=%%b

select into in mysql

Use the CREATE TABLE SELECT syntax.

http://dev.mysql.com/doc/refman/5.0/en/create-table-select.html

CREATE TABLE new_tbl SELECT * FROM orig_tbl;

javax.persistence.PersistenceException: No Persistence provider for EntityManager named customerManager

If you are using Maven you may have both src/{main,test}/resources/META-INF/persistence.xml. This is a common setup: test your JPA code with h2 or Derby and deploy it with PostgreSQL or some other full DBMS. If you're using this pattern, do make sure the two files have different unit names, else some versions of the Persistence class will try to load BOTH (because of course your test-time CLASSPATH includes both classes and test-classes); this will cause conflicting definitions of the persistence unit, resulting in the dreaded annoying message that we all hate so much!

Worse: this may "work" with some older versions of e.g., Hibernate, but fail with current versions. Worth getting it right anyway...

PHP Create and Save a txt file to root directory

If you are running PHP on Apache then you can use the enviroment variable called DOCUMENT_ROOT. This means that the path is dynamic, and can be moved between servers without messing about with the code.

<?php
  $fileLocation = getenv("DOCUMENT_ROOT") . "/myfile.txt";
  $file = fopen($fileLocation,"w");
  $content = "Your text here";
  fwrite($file,$content);
  fclose($file);
?>

How to add a default include path for GCC in Linux?

A gcc spec file can do the job, however all users on the machine will be affected.

See here

Best way to convert list to comma separated string in java

From Apache Commons library:

import org.apache.commons.lang3.StringUtils

Use:

StringUtils.join(slist, ',');

Another similar question and answer here

Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified"

I was having this same issue this morning. When I checked my Device Manager, it showed COM4 properly, and when I checked in the Arduino IDE COM4 just wasn't an option. Only COM1 was listed.
I tried unplugging and plugging my Arduino in and out a couple more times and eventually COM4 showed up again in the IDE. I didn't have to change any settings.
Hopefully that helps somebody.

How do I get cURL to not show the progress bar?

In curl version 7.22.0 on Ubuntu and 7.24.0 on OSX the solution to not show progress but to show errors is to use both -s (--silent) and -S (--show-error) like so:

curl -sS http://google.com > temp.html

This works for both redirected output > /some/file, piped output | less and outputting directly to the terminal for me.

Update: Since curl 7.67.0 there is a new option --no-progress-meter which does precisely this and nothing else, see clonejo's answer for more details.

How to check if mod_rewrite is enabled in php?

Use this function:

function apache_module_exists($module)
{
    return in_array($module, apache_get_modules());
}

Get last field using awk substr

If you're open to a Perl solution, here one similar to fedorqui's awk solution:

perl -F/ -lane 'print $F[-1]' input

-F/ specifies / as the field separator
$F[-1] is the last element in the @F autosplit array

Angular2 If ngModel is used within a form tag, either the name attribute must be set or the form

Try this...

<input type="text" class="form-control" name="name" placeholder="Name" required minlength="4" #name="ngModel" ngModel>
<div *ngIf="name.errors && (name.dirty || name.touched)">
    <div [hidden]="!name.errors.required" class="alert alert-danger form-alert">
        Please enter a name.
    </div>
    <div [hidden]="!name.errors.minlength" class="alert alert-danger form-alert">
        Enter name greater than 4 characters.
    </div>
</div>

How to send a simple email from a Windows batch file?

Max is on he right track with the suggestion to use Windows Scripting for a way to do it without installing any additional executables on the machine. His code will work if you have the IIS SMTP service setup to forward outbound email using the "smart host" setting, or the machine also happens to be running Microsoft Exchange. Otherwise if this is not configured, you will find your emails just piling up in the message queue folder (\inetpub\mailroot\queue). So, unless you can configure this service, you also want to be able to specify the email server you want to use to send the message with. To do that, you can do something like this in your windows script file:

Set objMail = CreateObject("CDO.Message")
Set objConf = CreateObject("CDO.Configuration")
Set objFlds = objConf.Fields
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/sendusing") = 2 'cdoSendUsingPort
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/smtpserver") = "smtp.your-site-url.com" 'your smtp server domain or IP address goes here
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 25 'default port for email
'uncomment next three lines if you need to use SMTP Authorization
'objFlds.Item("http://schemas.microsoft.com/cdo/configuration/sendusername") = "your-username"
'objFlds.Item("http://schemas.microsoft.com/cdo/configuration/sendpassword") = "your-password"
'objFlds.Item("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = 1 'cdoBasic
objFlds.Update
objMail.Configuration = objConf
objMail.FromName = "Your Name"
objMail.From = "[email protected]"
objMail.To = "[email protected]"
objMail.Subject = "Email Subject Text"
objMail.TextBody = "The message of the email..."
objMail.Send
Set objFlds = Nothing
Set objConf = Nothing
Set objMail = Nothing

How to increment an iterator by 2?

Assuming list size may not be an even multiple of step you must guard against overflow:

static constexpr auto step = 2;

// Guard against invalid initial iterator.
if (!list.empty())
{
    for (auto it = list.begin(); /*nothing here*/; std::advance(it, step))
    {
        // do stuff...

        // Guard against advance past end of iterator.
        if (std::distance(it, list.end()) > step)
            break;
    }
}

Depending on the collection implementation, the distance computation may be very slow. Below is optimal and more readable. The closure could be changed to a utility template with the list end value passed by const reference:

const auto advance = [&](list_type::iterator& it, size_t step)
{
    for (size_t i = 0; it != list.end() && i < step; std::next(it), ++i);
};

static constexpr auto step = 2;

for (auto it = list.begin(); it != list.end(); advance(it, step))
{
    // do stuff...
}

If there is no looping:

static constexpr auto step = 2;
auto it = list.begin();

if (step <= list.size())
{
    std::advance(it, step);
}

How do I make a "div" button submit the form its sitting in?

Why does everyone have to complicate things. Just use jQuery!

<script type="text/javascript">
  $(document).ready(function() {
    $('#divID').click(function(){
      $('#formID').submit();
    )};
    $('#submitID').hide();
  )};
</script>

<form name="whatever" method="post" action="somefile.php" id="formID">
  <input type="hidden" name="test" value="somevalue" />
  <input type="submit" name="submit" value="Submit" id="submitID" />
</form>

<div id="divID">Click Me to Submit</div>

The div doesn't even have to be in the form to submit it. The only thing that is missing here is the include of jquery.js.

Also, there is a Submit button that is hidden by jQuery, so if a non compatible browser is used, the submit button will show and allow the user to submit the form.

How to check if a variable is null or empty string or all whitespace in JavaScript?

Try this out

/**
  * Checks the string if undefined, null, not typeof string, empty or space(s)
  * @param {any} str string to be evaluated
  * @returns {boolean} the evaluated result
*/
function isStringNullOrWhiteSpace(str) {
    return str === undefined || str === null
                             || typeof str !== 'string'
                             || str.match(/^ *$/) !== null;
}

You can use it like this

isStringNullOrWhiteSpace('Your String');

How to insert a new key value pair in array in php?

Try this:

foreach($array as $k => $obj) { 
    $obj->{'newKey'} = "value"; 
}

Can't install any package with node npm

The problem is with ssl

you should use sudo. Follow below method to resolve the issue.

if you are getting this issue enter sudo npm config set strict-ssl false password: Enter current username password

then now run all ur command wit sudo sudo npm npm install -g underscore password: Enter current username password

Even after if your getting error. Your proxy will be problem. few corporate proxy will be blocked, so you should use wifi or open network to fix this issue.

Stash just a single file

I think stash -p is probably the choice you want, but just in case you run into other even more tricky things in the future, remember that:

Stash is really just a very simple alternative to the only slightly more complex branch sets. Stash is very useful for moving things around quickly, but you can accomplish more complex things with branches without that much more headache and work.

# git checkout -b tmpbranch
# git add the_file
# git commit -m "stashing the_file"
# git checkout master

go about and do what you want, and then later simply rebase and/or merge the tmpbranch. It really isn't that much extra work when you need to do more careful tracking than stash will allow.

Default text which won't be shown in drop-down list

Kyle's solution worked perfectly fine for me so I made my research in order to avoid any Js and CSS, but just sticking with HTML. Adding a value of selected to the item we want to appear as a header forces it to show in the first place as a placeholder. Something like:

<option selected disabled>Choose here</option>

The complete markup should be along these lines:

<select>
    <option selected disabled>Choose here</option>
    <option value="1">One</option>
    <option value="2">Two</option>
    <option value="3">Three</option>
    <option value="4">Four</option>
    <option value="5">Five</option>
</select>

You can take a look at this fiddle, and here's the result:

enter image description here

If you do not want the sort of placeholder text to appear listed in the options once a user clicks on the select box just add the hidden attribute like so:

<select>
    <option selected disabled hidden>Choose here</option>
    <option value="1">One</option>
    <option value="2">Two</option>
    <option value="3">Three</option>
    <option value="4">Four</option>
    <option value="5">Five</option>
</select>

Check the fiddle here and the screenshot below.

enter image description here


Here is the solution:

<select>
    <option style="display:none;" selected>Select language</option>
    <option>Option 1</option>
    <option>Option 2</option>
</select>

Remove values from select list based on condition

A few caveats not covered in most answers:

  • Check against multiple items (some should be deleted, some should remain)
  • Skip the first option (-Select-) on some option lists

A take on these:

const eligibleOptions = ['800000002', '800000001'];
let optionsList = document.querySelector("select#edit-salutation");
for (let i = 1; i<optionsList.length; i++) {
    if(eligibleOptions.indexOf(optionsList.options[i].value) === -1) {
        cbxSal.remove(i);
        i--;
    }
}

git push rejected: error: failed to push some refs

git push -f if you have permission, but that will screw up anyone else who pulls from that repo, so be careful.

If that is denied, and you have access to the server, as canzar says below, you can allow this on the server with

git config receive.denyNonFastForwards false

Comparing double values in C#

double and Double are the same (double is an alias for Double) and can be used interchangeably.

The problem with comparing a double with another value is that doubles are approximate values, not exact values. So when you set x to 0.1 it may in reality be stored as 0.100000001 or something like that.

Instead of checking for equality, you should check that the difference is less than a defined minimum difference (tolerance). Something like:

if (Math.Abs(x - 0.1) < 0.0000001)
{
    ...
}

Parsing query strings on Android

You say "Java" but "not Java EE". Do you mean you are using JSP and/or servlets but not a full Java EE stack? If that's the case, then you should still have request.getParameter() available to you.

If you mean you are writing Java but you are not writing JSPs nor servlets, or that you're just using Java as your reference point but you're on some other platform that doesn't have built-in parameter parsing ... Wow, that just sounds like an unlikely question, but if so, the principle would be:

xparm=0
word=""
loop
  get next char
  if no char
    exit loop
  if char=='='
    param_name[xparm]=word
    word=""
  else if char=='&'
    param_value[xparm]=word
    word=""
    xparm=xparm+1
  else if char=='%'
    read next two chars
    word=word+interpret the chars as hex digits to make a byte
  else
    word=word+char

(I could write Java code but that would be pointless, because if you have Java available, you can just use request.getParameters.)

Which is best data type for phone number in MySQL and what should Java type mapping for it be?

Consider using the E.164 format. For full international support, you'd need a VARCHAR of 15 digits.

See Twilio's recommendation for more information on localization of phone numbers.

What is the shortcut in IntelliJ IDEA to find method / functions?

ctrl + F12 (cmd + F12 on macOS) will show all members of the current class in a popup window and let you pick up one. It works exactly like the ctrl + o shortcut in eclipse, much faster than ctrl + alt + shift + n

Finding and removing non ascii characters from an Oracle Varchar2

I wouldn't recommend it for production code, but it makes sense and seems to work:

SELECT REGEXP_REPLACE(COLUMN,'[^' || CHR(1) || '-' || CHR(127) || '],'')

Facebook API "This app is in development mode"

This problem occurs when we set our app as unavailable to the public. 

STEP 1

Open Facebook developer account

https://www.facebook.com/login/?next=https%3A%2F%2Fdevelopers.facebook.com%2Fdocs%2Ffacebook-login%2Fios

enter image description here

STEP 2

Select your application

enter image description here

STEP 3

Click the app Review tab.

enter image description here

Change switch value no to yes. See picture below.

enter image description here

After this your app is live.

checking for typeof error in JS

You can use the instanceof operator (but see caveat below!).

var myError = new Error('foo');
myError instanceof Error // true
var myString = "Whatever";
myString instanceof Error // false

The above won't work if the error was thrown in a different window/frame/iframe than where the check is happening. In that case, the instanceof Error check will return false, even for an Error object. In that case, the easiest approach is duck-typing.

if (myError && myError.stack && myError.message) {
  // it's an error, probably
}

However, duck-typing may produce false positives if you have non-error objects that contain stack and message properties.

AngularJS Folder Structure

enter image description here

Sort By Type

On the left we have the app organized by type. Not too bad for smaller apps, but even here you can start to see it gets more difficult to find what you are looking for. When I want to find a specific view and its controller, they are in different folders. It can be good to start here if you are not sure how else to organize the code as it is quite easy to shift to the technique on the right: structure by feature.

Sort By Feature (preferred)

On the right the project is organized by feature. All of the layout views and controllers go in the layout folder, the admin content goes in the admin folder, and the services that are used by all of the areas go in the services folder. The idea here is that when you are looking for the code that makes a feature work, it is located in one place. Services are a bit different as they “service” many features. I like this once my app starts to take shape as it becomes a lot easier to manage for me.

A well written blog post: http://www.johnpapa.net/angular-growth-structure/

Example App: https://github.com/angular-app/angular-app

addClass and removeClass in jQuery - not removing class

I think that the problem is in the nesting of the elements. Once you attach an event to the outer element the clicks on the inner elements are actually firing the same click event for the outer element. So, you actually never go to the second state. What you can do is to check the clicked element. And if it is the close button then to avoid the class changing. Here is my solution:

var element = $(".clickable");
var closeButton = element.find(".close_button");
var onElementClick = function(e) {
    if(e.target !== closeButton[0]) {
        element.removeClass("spot").addClass("grown");
        element.off("click");
        closeButton.on("click", onCloseClick);
    }
}
var onCloseClick = function() {
    element.removeClass("grown").addClass("spot");
    closeButton.off("click");
    element.on("click", onElementClick);
}
element.on("click", onElementClick);

In addition I'm adding and removing event handlers.

JSFiddle -> http://jsfiddle.net/zmw9E/1/

What is difference between cacerts and keystore?

cacerts is where Java stores public certificates of root CAs. Java uses cacerts to authenticate the servers.

Keystore is where Java stores the private keys of the clients so that it can share it to the server when the server requests client authentication.

Reading tab-delimited file with Pandas - works on Windows, but not on Mac

The biggest clue is the rows are all being returned on one line. This indicates line terminators are being ignored or are not present.

You can specify the line terminator for csv_reader. If you are on a mac the lines created will end with \rrather than the linux standard \n or better still the suspenders and belt approach of windows with \r\n.

pandas.read_csv(filename, sep='\t', lineterminator='\r')

You could also open all your data using the codecs package. This may increase robustness at the expense of document loading speed.

import codecs

doc = codecs.open('document','rU','UTF-16') #open for reading with "universal" type set

df = pandas.read_csv(doc, sep='\t')

How to write multiple line string using Bash with variables?

If you do not want variables to be replaced, you need to surround EOL with single quotes.

cat >/tmp/myconfig.conf <<'EOL'
line 1, ${kernel}
line 2, 
line 3, ${distro}
line 4 line
... 
EOL

Previous example:

$ cat /tmp/myconfig.conf 
line 1, ${kernel}
line 2, 
line 3, ${distro}
line 4 line
... 

CSS for the "down arrow" on a <select> element?

You would need to create your own dropdown using hidden divs and a hidden input element to record which option was "selected". My guess is that @Jan Hancic's link he posted is probably what you're looking for.

Instance member cannot be used on type

Sometimes Xcode when overrides methods adds class func instead of just func. Then in static method you can't see instance properties. It is very easy to overlook it. That was my case.

enter image description here

Reading in double values with scanf in c

Use this line of code when scanning the second value: scanf(" %lf", &b); also replace all %ld with %lf.

It's a problem related with input stream buffer. You can also use fflush(stdin); after the first scanning to clear the input buffer and then the second scanf will work as expected. An alternate way is place a getch(); or getchar(); function after the first scanf line.

Difference between "enqueue" and "dequeue"

A queue is a certain 2-sided data structure. You can add new elements on one side, and remove elements from the other side (as opposed to a stack that has only one side). Enqueue means to add an element, dequeue to remove an element. Please have a look here.

How to call a JavaScript function, declared in <head>, in the body when I want to call it

You can call it like that:

<!DOCTYPE html>
<html lang="en">
    <head>
        <script type="text/javascript">
            var person = { name: 'Joe Blow' };
            function myfunction() {
               document.write(person.name);
            }
        </script>
    </head>
    <body>
        <script type="text/javascript">
            myfunction();
        </script>
    </body>
</html>

The result should be page with the only content: Joe Blow

Look here: http://jsfiddle.net/HWreP/

Best regards!

Getting value of selected item in list box as string

If you want to retrieve the item selected from listbox, here is the code...

String SelectedItem = listBox1.SelectedItem.Value;

How to check if variable is array?... or something array-like

You can check instance of Traversable with a simple function. This would work for all this of Iterator because Iterator extends Traversable

function canLoop($mixed) {
    return is_array($mixed) || $mixed instanceof Traversable ? true : false;
}

2D cross-platform game engine for Android and iOS?

V-Play (v-play.net) is a cross-platform game engine based on Qt/QML with many useful V-Play QML game components for handling multiple display resolutions & aspect ratios, animations, particles, physics, multi-touch, gestures, path finding and more. API reference The engine core is written in native C++, combined with the custom renderer, the games reach a solid performance of 60fps across all devices.

V-Play also comes with ready-to-use game templates for the most successful game genres like tower defense, platform games or puzzle games.

If you are curious about games made with V-Play, here is a quick selection of them:

(Disclaimer: I'm one of the guys behind V-Play)

What does the PHP error message "Notice: Use of undefined constant" mean?

You should quote your array keys:

$department = mysql_real_escape_string($_POST['department']);
$name = mysql_real_escape_string($_POST['name']);
$email = mysql_real_escape_string($_POST['email']);
$message = mysql_real_escape_string($_POST['message']);

As is, it was looking for constants called department, name, email, message, etc. When it doesn't find such a constant, PHP (bizarrely) interprets it as a string ('department', etc). Obviously, this can easily break if you do defined such a constant later (though it's bad style to have lower-case constants).

Set width of a "Position: fixed" div relative to parent div

I´m not sure as to what the second problem is (based on your edit), but if you apply width:inherit to all inner divs, it works: http://jsfiddle.net/4bGqF/9/

You might want to look into a javascript solution for browsers that you need to support and that don´t support width:inherit

How to perform a sum of an int[] array

Here is an efficient way to solve this question using For loops in Java

 public static void main(String[] args) {

    int [] numbers = { 1, 2, 3, 4 };
    int size = numbers.length;

    int sum = 0;
    for (int i = 0; i < size; i++) {
        sum += numbers[i];
    }

    System.out.println(sum);
}

RSpec: how to test if a method was called?

To fully comply with RSpec ~> 3.1 syntax and rubocop-rspec's default option for rule RSpec/MessageSpies, here's what you can do with spy:

Message expectations put an example's expectation at the start, before you've invoked the code-under-test. Many developers prefer using an arrange-act-assert (or given-when-then) pattern for structuring tests. Spies are an alternate type of test double that support this pattern by allowing you to expect that a message has been received after the fact, using have_received.

# arrange.
invitation = spy('invitation')

# act.
invitation.deliver("[email protected]")

# assert.
expect(invitation).to have_received(:deliver).with("[email protected]")

If you don't use rubocop-rspec or using non-default option. You may, of course, use RSpec 3 default with expect.

dbl = double("Some Collaborator")
expect(dbl).to receive(:foo).with("[email protected]")

WELD-001408: Unsatisfied dependencies for type Customer with qualifiers @Default

To inject an Object, its class must be known to the CDI mechanism. Usualy adding the @Named annotation will do the trick.

What is the meaning of "POSIX"?

POSIX stands for Portable Operating System Interface, and is an IEEE standard designed to facilitate application portability. POSIX is an attempt by a consortium of vendors to create a single standard version of UNIX.

How to insert tab character when expandtab option is on in Vim

You can use <CTRL-V><Tab> in "insert mode". In insert mode, <CTRL-V> inserts a literal copy of your next character.

If you need to do this often, @Dee`Kej suggested (in the comments) setting Shift+Tab to insert a real tab with this mapping:

:inoremap <S-Tab> <C-V><Tab>

Also, as noted by @feedbackloop, on Windows you may need to press <CTRL-Q> rather than <CTRL-V>.

CSS: Truncate table cells, but fit as much as possible

I had the same issue, but I needed to display multiple lines (where text-overflow: ellipsis; fails). I solve it using a textarea inside a TD and then style it to behave like a table cell.

    textarea {
        margin: 0;
        padding: 0;
        width: 100%;
        border: none;
        resize: none;

        /* Remove blinking cursor (text caret) */
        color: transparent;
        display: inline-block;
        text-shadow: 0 0 0 black; /* text color is set to transparent so use text shadow to draw the text */
        &:focus {
            outline: none;
        }
    }

How can I resolve "Your requirements could not be resolved to an installable set of packages" error?

"config": {
  "platform": {
    "ext-pcntl": "7.2",
    "ext-posix": "7.2"
  }
}

If statement within Where clause

You can't use IF like that. You can do what you want with AND and OR:

SELECT t.first_name,
       t.last_name,
       t.employid,
       t.status
  FROM employeetable t
 WHERE ((status_flag = STATUS_ACTIVE   AND t.status = 'A')
     OR (status_flag = STATUS_INACTIVE AND t.status = 'T')
     OR (source_flag = SOURCE_FUNCTION AND t.business_unit = 'production')
     OR (source_flag = SOURCE_USER     AND t.business_unit = 'users'))
   AND t.first_name LIKE firstname
   AND t.last_name  LIKE lastname
   AND t.employid   LIKE employeeid;

How to generate Javadoc HTML files in Eclipse?

You can also do it from command line much easily.

  1. Open command line from the folder/package.
  2. From command line run:

    javadoc YourClassName.java

  3. To batch generate docs for multiple Class:

    javadoc *.java

How to parse JSON with VBA without external libraries?

I've found this script example useful (from http://www.mrexcel.com/forum/excel-questions/898899-json-api-excel.html#post4332075 ):

Sub getData()

    Dim Movie As Object
    Dim scriptControl As Object

    Set scriptControl = CreateObject("MSScriptControl.ScriptControl")
    scriptControl.Language = "JScript"

    With CreateObject("MSXML2.XMLHTTP")
        .Open "GET", "http://www.omdbapi.com/?t=frozen&y=&plot=short&r=json", False
        .send
        Set Movie = scriptControl.Eval("(" + .responsetext + ")")
        .abort
        With Sheets(2)
            .Cells(1, 1).Value = Movie.Title
            .Cells(1, 2).Value = Movie.Year
            .Cells(1, 3).Value = Movie.Rated
            .Cells(1, 4).Value = Movie.Released
            .Cells(1, 5).Value = Movie.Runtime
            .Cells(1, 6).Value = Movie.Director
            .Cells(1, 7).Value = Movie.Writer
            .Cells(1, 8).Value = Movie.Actors
            .Cells(1, 9).Value = Movie.Plot
            .Cells(1, 10).Value = Movie.Language
            .Cells(1, 11).Value = Movie.Country
            .Cells(1, 12).Value = Movie.imdbRating
        End With
    End With

End Sub

How can I get a list of Git branches, ordered by most recent commit?

Here is a simple command that lists all branches with latest commits:

git branch -v

To order by most recent commit, use

git branch -v --sort=committerdate

Source: http://git-scm.com/book/en/Git-Branching-Branch-Management

dropdownlist set selected value in MVC3 Razor

I want to put the correct answer in here, just in case others are having this problem like I was. If you hate the ViewBag, fine don't use it, but the real problem with the code in the question is that the same name is being used for both the model property and the selectlist as was pointed out by @RickAndMSFT

Simply changing the name of the DropDownList control should resolve the issue, like so:

@Html.DropDownList("NewsCategoriesSelection", (SelectList)ViewBag.NewsCategoriesID)

It doesn't really have anything to do with using the ViewBag or not using the ViewBag as you can have a name collision with the control regardless.

Pure CSS animation visibility with delay

You can play with delay prop of animation, just set visibility:visible after a delay, demo:

_x000D_
_x000D_
@keyframes delayedShow {_x000D_
  to {_x000D_
    visibility: visible;_x000D_
  }_x000D_
}_x000D_
_x000D_
.delayedShow{_x000D_
  visibility: hidden;_x000D_
  animation: 0s linear 2.3s forwards delayedShow ;_x000D_
}
_x000D_
So, Where are you?_x000D_
_x000D_
<div class="delayedShow">_x000D_
  Hey, I'm here!_x000D_
</div>
_x000D_
_x000D_
_x000D_

Converting list to *args when calling function

You can use the * operator before an iterable to expand it within the function call. For example:

timeseries_list = [timeseries1 timeseries2 ...]
r = scikits.timeseries.lib.reportlib.Report(*timeseries_list)

(notice the * before timeseries_list)

From the python documentation:

If the syntax *expression appears in the function call, expression must evaluate to an iterable. Elements from this iterable are treated as if they were additional positional arguments; if there are positional arguments x1, ..., xN, and expression evaluates to a sequence y1, ..., yM, this is equivalent to a call with M+N positional arguments x1, ..., xN, y1, ..., yM.

This is also covered in the python tutorial, in a section titled Unpacking argument lists, where it also shows how to do a similar thing with dictionaries for keyword arguments with the ** operator.

Raise an error manually in T-SQL to jump to BEGIN CATCH block

SQL has an error raising mechanism

RAISERROR ( { msg_id | msg_str | @local_variable }
{ ,severity ,state }
[ ,argument [ ,...n ] ] )
[ WITH option [ ,...n ] ]

Just look up Raiserror in the Books Online. But.. you have to generate an error of the appropriate severity, an error at severity 0 thru 10 do not cause you to jump to the catch block.

javascript: using a condition in switch case

Notice that we don't pass score to the switch but true. The value we give to the switch is used as the basis to compare against.

The below example shows how we can add conditions in the case: without any if statements.

function getGrade(score) {
    let grade;
    // Write your code here
    switch(true) {
        case score >= 0 && score <= 5:
        grade = 'F';
        break;
        case score > 5 && score <= 10:
        grade = 'E';
        break;
        case score > 10 && score <= 15:
        grade = 'D';
        break;
        case score > 15 && score <= 20:
        grade = 'C';
        break;
        case score > 20 && score <= 25:
        grade = 'B';
        break;
        case score > 25 && score <= 30:
        grade = 'A';
        break;
    }

    return grade;
}

catch forEach last iteration

The 2018 ES6+ ANSWER IS:

    const arr = [1, 2, 3];

    arr.forEach((val, key, arr) => {
      if (Object.is(arr.length - 1, key)) {
        // execute last item logic
        console.log(`Last callback call at index ${key} with value ${val}` ); 
      }
    });

How to match "anything up until this sequence of characters" in a regular expression?

On python:

.+?(?=abc) works for the single line case.

[^]+?(?=abc) does not work, since python doesn't recognize [^] as valid regex. To make multiline matching work, you'll need to use the re.DOTALL option, for example:

re.findall('.+?(?=abc)', data, re.DOTALL)

REST API Login Pattern

Principled Design of the Modern Web Architecture by Roy T. Fielding and Richard N. Taylor, i.e. sequence of works from all REST terminology came from, contains definition of client-server interaction:

All REST interactions are stateless. That is, each request contains all of the information necessary for a connector to understand the request, independent of any requests that may have preceded it.

This restriction accomplishes four functions, 1st and 3rd are important in this particular case:

  • 1st: it removes any need for the connectors to retain application state between requests, thus reducing consumption of physical resources and improving scalability;
  • 3rd: it allows an intermediary to view and understand a request in isolation, which may be necessary when services are dynamically rearranged;

And now lets go back to your security case. Every single request should contains all required information, and authorization/authentication is not an exception. How to achieve this? Literally send all required information over wires with every request.

One of examples how to archeive this is hash-based message authentication code or HMAC. In practice this means adding a hash code of current message to every request. Hash code calculated by cryptographic hash function in combination with a secret cryptographic key. Cryptographic hash function is either predefined or part of code-on-demand REST conception (for example JavaScript). Secret cryptographic key should be provided by server to client as resource, and client uses it to calculate hash code for every request.

There are a lot of examples of HMAC implementations, but I'd like you to pay attention to the following three:

How it works in practice

If client knows the secret key, then it's ready to operate with resources. Otherwise he will be temporarily redirected (status code 307 Temporary Redirect) to authorize and to get secret key, and then redirected back to the original resource. In this case there is no need to know beforehand (i.e. hardcode somewhere) what the URL to authorize the client is, and it possible to adjust this schema with time.

Hope this will helps you to find the proper solution!

max value of integer

It is actually really simple to understand, you can even compute it with the google calculator: you have 32 bits for an int and computers are binary, therefore you can have 2 values per bit (spot). if you compute 2^32 you will get the 4,294,967,296. so if you divide this number by 2, (because half of them are negative integers and the other half are positive), then you get 2,147,483,648. and this number is the biggest int that can be represented by 32 bits, although if you pay attention you will notice that 2,147,483,648 is greater than 2,147,483,647 by 1, this is because one of the numbers represents 0 which is right in the middle unfortunately 2^32 is not an odd number therefore you dont have only one number in the middle, so the possitive integers have one less cipher while the negatives get the complete half 2,147,483,648.

And thats it. It depends on the machine not on the language.

Unexpected token < in first line of HTML

I had this problem in an ASP.NET application, specifically a Web Forms.

I was forcing a redirect in Global.asax, but I forgot to check if the request was for resources like css, javascript, etc. I just had to add the following checks:

VB.NET

If Not Response.IsRequestBeingRedirected _
    And Not Request.Url.AbsoluteUri.Contains(".WebResource") _
    And Not Request.Url.AbsoluteUri.Contains(".css") _
    And Not Request.Url.AbsoluteUri.Contains(".js") _
    And Not Request.Url.AbsoluteUri.Contains("images/") _
    And Not Request.Url.AbsoluteUri.Contains("favicon") Then
        Response.Redirect("~/change-password.aspx")
End If

I was forcing logged users which hadn't change their passwords for a long time, to be redirected to the change-password.aspx page. I believe there is a better way to check this, but for now, this worked. Should I find a better solution, I edit my answer.

Identifier is undefined

You may also be missing using namespace std;

Choose Git merge strategy for specific files ("ours", "mine", "theirs")

For each conflicted file you get, you can specify

git checkout --ours -- <paths>
# or
git checkout --theirs -- <paths>

From the git checkout docs

git checkout [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>...

--ours
--theirs
When checking out paths from the index, check out stage #2 (ours) or #3 (theirs) for unmerged paths.

The index may contain unmerged entries because of a previous failed merge. By default, if you try to check out such an entry from the index, the checkout operation will fail and nothing will be checked out. Using -f will ignore these unmerged entries. The contents from a specific side of the merge can be checked out of the index by using --ours or --theirs. With -m, changes made to the working tree file can be discarded to re-create the original conflicted merge result.

Xcode doesn't see my iOS device but iTunes does

I just barely tried every solution suggested above. The only thing that worked and resolved my issue was to go into xcode's "Organizer", right click on my iPhone, click on "Remove from organizer" and then wait about 10 seconds while xcode automatically re-added the device.

I previously plugged in my phone and itunes recognized it fine and synced with it, etc, but all xcode said in the organizer was "Device is not currently connected", which it was most definitely connected if itunes was syncing with it and not syncing over wi-fi.

Why xcode needed me to delete and re-add the phone is beyond me, but it works great now that I did this.

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

The way your question is phrased makes it sound like you think you have to physically resort the data in the table in order to get it back in the order you want. If so, this is not the case, the ORDER BY clause exists for this purpose. The physical order in which the records are stored remains unchanged when using ORDER BY. The records are sorted in memory (or in temporary disk space) before they are returned.

Note that the order that records get returned is not guaranteed without using an ORDER BY clause. So, while any of the the suggestions here may work, there is no reason to think they will continue to work, nor can you prove that they work in all cases with your current database. This is by design - I am assuming it is to give the database engine the freedom do as it will with the records in order to obtain best performance in the case where there is no explicit order specified.

Assuming you wanted the last 5 records sorted by the field Name in ascending order, you could do something like this, which should work in either SQL 2000 or 2005:

select Name 
from (
    select top 5 Name 
    from MyTable 
    order by Name desc
) a 
order by Name asc

How do I find an element that contains specific text in Selenium WebDriver (Python)?

You can also use it with Page Object Pattern, e.g:

Try this code:

@FindBy(xpath = "//*[contains(text(), 'Best Choice')]")
WebElement buttonBestChoice;

What HTTP status response code should I use if the request is missing a required parameter?

You can send a 400 Bad Request code. It's one of the more general-purpose 4xx status codes, so you can use it to mean what you intend: the client is sending a request that's missing information/parameters that your application requires in order to process it correctly.

How can I create basic timestamps or dates? (Python 3.4)

Ultimately you want to review the datetime documentation and become familiar with the formatting variables, but here are some examples to get you started:

import datetime

print('Timestamp: {:%Y-%m-%d %H:%M:%S}'.format(datetime.datetime.now()))
print('Timestamp: {:%Y-%b-%d %H:%M:%S}'.format(datetime.datetime.now()))
print('Date now: %s' % datetime.datetime.now())
print('Date today: %s' % datetime.date.today())

today = datetime.date.today()
print("Today's date is {:%b, %d %Y}".format(today))

schedule = '{:%b, %d %Y}'.format(today) + ' - 6 PM to 10 PM Pacific'
schedule2 = '{:%B, %d %Y}'.format(today) + ' - 1 PM to 6 PM Central'
print('Maintenance: %s' % schedule)
print('Maintenance: %s' % schedule2)

The output:

Timestamp: 2014-10-18 21:31:12

Timestamp: 2014-Oct-18 21:31:12

Date now: 2014-10-18 21:31:12.318340

Date today: 2014-10-18

Today's date is Oct, 18 2014

Maintenance: Oct, 18 2014 - 6 PM to 10 PM Pacific

Maintenance: October, 18 2014 - 1 PM to 6 PM Central

Reference link: https://docs.python.org/3.4/library/datetime.html#strftime-strptime-behavior

What and When to use Tuple?

A tuple allows you to combine multiple values of possibly different types into a single object without having to create a custom class. This can be useful if you want to write a method that for example returns three related values but you don't want to create a new class.

Usually though you should create a class as this allows you to give useful names to each property. Code that extensively uses tuples will quickly become unreadable because the properties are called Item1, Item2, Item3, etc..

Conditional operator in Python?

simple is the best and works in every version.

if a>10: 
    value="b"
else: 
    value="c"

run program in Python shell

If you want to avoid writing all of this everytime, you can define a function :

def run(filename):
    exec(open(filename).read())

and then call it

run('filename.py')

How can I check if a single character appears in a string?

To check if something does not exist in a string, you at least need to look at each character in a string. So even if you don't explicitly use a loop, it'll have the same efficiency. That being said, you can try using str.contains(""+char).

Get $_POST from multiple checkboxes

Edit To reflect what @Marc said in the comment below.

You can do a loop through all the posted values.

HTML:

<input type="checkbox" name="check_list[]" value="<?=$rowid?>" />
<input type="checkbox" name="check_list[]" value="<?=$rowid?>" />
<input type="checkbox" name="check_list[]" value="<?=$rowid?>" />

PHP:

foreach($_POST['check_list'] as $item){
  // query to delete where item = $item
}

Bootstrap 3: how to make head of dropdown link clickable in navbar

i know its too late but anyone who came here for help now you can see this post .There are two options either use css/ JavaScript and if you use css it will be applicable to devices greater that 769px width for clickable top menu, that will be work perfectly f

See here for article

How to use jQuery to get the current value of a file input field

In Chrome 8 the path is always 'C:\fakepath\' with the correct file name.

MD5 is 128 bits but why is it 32 characters?

A hex "character" (nibble) is different from a "character"

To be clear on the bits vs byte, vs characters.

  • 1 byte is 8 bits (for our purposes)
  • 8 bits provides 2**8 possible combinations: 256 combinations

When you look at a hex character,

  • 16 combinations of [0-9] + [a-f]: the full range of 0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f
  • 16 is less than 256, so one one hex character does not store a byte.
  • 16 is 2**4: that means one hex character can store 4 bits in a byte (half a byte).
  • Therefore, two hex characters, can store 8 bits, 2**8 combinations.
  • A byte represented as a hex character is [0-9a-f][0-9a-f] and that represents both halfs of a byte (we call a half-byte a nibble).

When you look at a regular single-byte character, (we're totally going to skip multi-byte and wide-characters here)

  • It can store far more than 16 combinations.
  • The capabilities of the character are determined by the encoding. For instance, the ISO 8859-1 that stores an entire byte, stores all this stuff
  • All that stuff takes the entire 2**8 range.
  • If a hex-character in an md5() could store all that, you'd see all the lowercase letters, all the uppercase letters, all the punctuation and things like ¡°ÀÐàð, whitespace like (newlines, and tabs), and control characters (which you can't even see and many of which aren't in use).

So they're clearly different and I hope that provides the best break down of the differences.

Get value of input field inside an iframe

Yes it should be possible, even if the site is from another domain.

For example, in an HTML page on my site I have an iFrame whose contents are sourced from another website. The iFrame content is a single select field.

I need to be able to read the selected value on my site. In other words, I need to use the select list from another domain inside my own application. I do not have control over any server settings.

Initially therefore we might be tempted to do something like this (simplified):

HTML in my site:

<iframe name='select_frame' src='http://www.othersite.com/select.php?initial_name=jim'></iframe>
<input type='button' name='save' value='SAVE'>

HTML contents of iFrame (loaded from select.php on another domain):

<select id='select_name'>
    <option value='john'>John</option>
    <option value='jim' selected>Jim</option>
</select>

jQuery:

$('input:button[name=save]').click(function() {
    var name = $('iframe[name=select_frame]').contents().find('#select_name').val();
});

However, I receive this javascript error when I attempt to read the value:

Blocked a frame with origin "http://www.myownsite.com" from accessing a frame with origin "http://www.othersite.com". Protocols, domains, and ports must match.

To get around this problem, it seems that you can indirectly source the iFrame from a script in your own site, and have that script read the contents from the other site using a method like file_get_contents() or curl etc.

So, create a script (for example: select_local.php in the current directory) on your own site with contents similar to this:

PHP content of select_local.php:

<?php
    $url = "http://www.othersite.com/select.php?" . $_SERVER['QUERY_STRING'];
    $html_select = file_get_contents($url);
    echo $html_select;
?>

Also modify the HTML to call this local (instead of the remote) script:

<iframe name='select_frame' src='select_local.php?initial_name=jim'></iframe>
<input type='button' name='save' value='SAVE'>

Now your browser should think that it is loading the iFrame content from the same domain.

add/remove active class for ul list with jquery?

I used this:

$('.nav-list li.active').removeClass('active');
$(this).parent().addClass('active');

Since the active class is in the <li> element and what is clicked is the <a> element, the first line removes .active from all <li> and the second one (again, $(this) represents <a> which is the clicked element) adds .active to the direct parent, which is <li>.

How do I resize a Google Map with JavaScript after it has loaded?

This is best it will do the Job done. It will re-size your Map. No need to inspect element anymore to re-size your Map. What it does it will automatically trigger re-size event .

    google.maps.event.addListener(map, "idle", function()
        {
            google.maps.event.trigger(map, 'resize');
        });

        map_array[Next].setZoom( map.getZoom() - 1 );
    map_array[Next].setZoom( map.getZoom() + 1 );

Code Sign error: The identity 'iPhone Developer' doesn't match any valid certificate/private key pair in the default keychain

if your certificate is not valid, it will have a red "x" and state the reason why. Generally the reason is "This certificate has expired" or "This certificate was signed by an unknown authority.

to solve this you need to do the following step.

  1. If your certificate has expired, renew it at the iPhone Portal, download it, and double-click it to add it to your Keychain.
  2. If it's "signed by an unknown authority", download the "Apple Worldwide Developer Relations" certificate from the Certificates section of the iPhone Developer portal and double-click it to add it to your Keychain.
  3. If your certificate was revoked, delete the certificate from your Keychain, then follow the "Obtaining your iPhone Development Certificate" or "Obtaining your iPhone Distribution Certificate" section in the iPhone Developer Program Portal User Guide to generate a new certificate.
  4. Make sure you create a backup of your private key. The steps for doing this are described in the iPhone Developer Program Portal User Guide, under "Saving your Private Key and Transferring to other Systems".
  5. If you have the iPhone Developer (or iPhone Distribution) certificate and its associated private key, the Apple WWDR Intermediate certificate is installed, and your certificate is valid, confirm that Online Certificate Status Protocol (OCSP) and Certificate Revocation List (CRL) are set to "Off" in Keychain Access > Preferences > Certificates.
  6. if you still getting problem then contact support apple community.

Wait until a process ends

You could use wait for exit or you can catch the HasExited property and update your UI to keep the user "informed" (expectation management):

System.Diagnostics.Process process = System.Diagnostics.Process.Start("cmd.exe");
while (!process.HasExited)
{
    //update UI
}
//done

Parser Error: '_Default' is not allowed here because it does not extend class 'System.Web.UI.Page' & MasterType declaration

For me I had all of the namespaces on the pages and none of the solutions above fixed it. My problem was in:

<%@ Page Language="C#" 
AutoEventWireup="true" 
CodeBehind="xxx.aspx.cs" 
Inherits="xxx.xxx.xxx" 
MasterPageFile="~masterurl/default.master" %>

Then in my aspx.cs file the namespace did not match the Inherits tag. So it needed

namespace xxx.xxx.xxx

In the .cs to match the Inherits.

How to indent/format a selection of code in Visual Studio Code with Ctrl + Shift + F

F1 → open Keyboard Shortcuts → search for 'Indent Line', and change keybinding to Tab.

Right click > "Change when expression" to editorHasSelection && editorTextFocus && !editorReadonly

It will allow you to indent line when something in that line is selected (multiple lines still work).

Which comment style should I use in batch files?

James K, I'm sorry I was wrong in a fair portion of what I said. The test I did was the following:

@ECHO OFF
(
  :: But
   : neither
  :: does
   : this
  :: also.
)

This meets your description of alternating but fails with a ") was unexpected at this time." error message.

I did some farther testing today and found that alternating isn't the key but it appears the key is having an even number of lines, not having any two lines in a row starting with double colons (::) and not ending in double colons. Consider the following:

@ECHO OFF
(
   : But
   : neither
   : does
   : this
   : cause
   : problems.
)

This works!

But also consider this:

@ECHO OFF
(
   : Test1
   : Test2
   : Test3
   : Test4
   : Test5
   ECHO.
)

The rule of having an even number of comments doesn't seems to apply when ending in a command.

Unfortunately this is just squirrelly enough that I'm not sure I want to use it.

Really, the best solution, and the safest that I can think of, is if a program like Notepad++ would read REM as double colons and then would write double colons back as REM statements when the file is saved. But I'm not aware of such a program and I'm not aware of any plugins for Notepad++ that does that either.

How exactly does binary code get converted into letters?

http://www.roubaixinteractive.com/PlayGround/Binary_Conversion/The_Characters.asp it just looks here... (not HERE but it has a table).

There are 8 bits in a byte. One byte can be one symbol. One bit is either on or off.

android listview get selected item

final ListView lv = (ListView) findViewById(R.id.ListView01);

lv.setOnItemClickListener(new OnItemClickListener() {
      public void onItemClick(AdapterView<?> myAdapter, View myView, int myItemInt, long mylng) {
        String selectedFromList =(String) (lv.getItemAtPosition(myItemInt));

      }                 
});

I hope this fixes your problem.

Difference between a script and a program?

I take a different view.

A "script" is code that acts upon some system in an external or independent manner and can be removed or disabled without disabling the system itself.

A "program" is code that constitutes a system. The program's code may be written in a modular manner, with good separation of concerns, but the code is fundamentally internal to, and a dependency of, the system itself.

Scripts are often interpreted, but not always. Programs are often compiled, but not always.

socket connect() vs bind()

From Wikipedia http://en.wikipedia.org/wiki/Berkeley_sockets#bind.28.29

connect():

The connect() system call connects a socket, identified by its file descriptor, to a remote host specified by that host's address in the argument list.

Certain types of sockets are connectionless, most commonly user datagram protocol sockets. For these sockets, connect takes on a special meaning: the default target for sending and receiving data gets set to the given address, allowing the use of functions such as send() and recv() on connectionless sockets.

connect() returns an integer representing the error code: 0 represents success, while -1 represents an error.

bind():

bind() assigns a socket to an address. When a socket is created using socket(), it is only given a protocol family, but not assigned an address. This association with an address must be performed with the bind() system call before the socket can accept connections to other hosts. bind() takes three arguments:

sockfd, a descriptor representing the socket to perform the bind on. my_addr, a pointer to a sockaddr structure representing the address to bind to. addrlen, a socklen_t field specifying the size of the sockaddr structure. Bind() returns 0 on success and -1 if an error occurs.

Examples: 1.)Using Connect

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>

int main(){
  int clientSocket;
  char buffer[1024];
  struct sockaddr_in serverAddr;
  socklen_t addr_size;

  /*---- Create the socket. The three arguments are: ----*/
  /* 1) Internet domain 2) Stream socket 3) Default protocol (TCP in this case) */
  clientSocket = socket(PF_INET, SOCK_STREAM, 0);

  /*---- Configure settings of the server address struct ----*/
  /* Address family = Internet */
  serverAddr.sin_family = AF_INET;
  /* Set port number, using htons function to use proper byte order */
  serverAddr.sin_port = htons(7891);
  /* Set the IP address to desired host to connect to */
  serverAddr.sin_addr.s_addr = inet_addr("192.168.1.17");
  /* Set all bits of the padding field to 0 */
  memset(serverAddr.sin_zero, '\0', sizeof serverAddr.sin_zero);  

  /*---- Connect the socket to the server using the address struct ----*/
  addr_size = sizeof serverAddr;
  connect(clientSocket, (struct sockaddr *) &serverAddr, addr_size);

  /*---- Read the message from the server into the buffer ----*/
  recv(clientSocket, buffer, 1024, 0);

  /*---- Print the received message ----*/
  printf("Data received: %s",buffer);   

  return 0;
}

2.)Bind Example:

int main()
{
    struct sockaddr_in source, destination = {};  //two sockets declared as previously
    int sock = 0;
    int datalen = 0;
    int pkt = 0;

    uint8_t *send_buffer, *recv_buffer;

    struct sockaddr_storage fromAddr;   // same as the previous entity struct sockaddr_storage serverStorage;
    unsigned int addrlen;  //in the previous example socklen_t addr_size;
    struct timeval tv;
    tv.tv_sec = 3;  /* 3 Seconds Time-out */
    tv.tv_usec = 0;

    /* creating the socket */         
    if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) 
        printf("Failed to create socket\n");

    /*set the socket options*/
    setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv, sizeof(struct timeval));

    /*Inititalize source to zero*/
    memset(&source, 0, sizeof(source));       //source is an instance of sockaddr_in. Initialization to zero
    /*Inititalize destinaton to zero*/
    memset(&destination, 0, sizeof(destination));


    /*---- Configure settings of the source address struct, WHERE THE PACKET IS COMING FROM ----*/
    /* Address family = Internet */
    source.sin_family = AF_INET;    
    /* Set IP address to localhost */   
    source.sin_addr.s_addr = INADDR_ANY;  //INADDR_ANY = 0.0.0.0
    /* Set port number, using htons function to use proper byte order */
    source.sin_port = htons(7005); 
    /* Set all bits of the padding field to 0 */
    memset(source.sin_zero, '\0', sizeof source.sin_zero); //optional


    /*bind socket to the source WHERE THE PACKET IS COMING FROM*/
    if (bind(sock, (struct sockaddr *) &source, sizeof(source)) < 0) 
        printf("Failed to bind socket");

    /* setting the destination, i.e our OWN IP ADDRESS AND PORT */
    destination.sin_family = AF_INET;                 
    destination.sin_addr.s_addr = inet_addr("127.0.0.1");  
    destination.sin_port = htons(7005); 

    //Creating a Buffer;
    send_buffer=(uint8_t *) malloc(350);
    recv_buffer=(uint8_t *) malloc(250);

    addrlen=sizeof(fromAddr);

    memset((void *) recv_buffer, 0, 250);
    memset((void *) send_buffer, 0, 350);

    sendto(sock, send_buffer, 20, 0,(struct sockaddr *) &destination, sizeof(destination));

    pkt=recvfrom(sock, recv_buffer, 98,0,(struct sockaddr *)&destination, &addrlen);
    if(pkt > 0)
        printf("%u bytes received\n", pkt);
    }

I hope that clarifies the difference

Please note that the socket type that you declare will depend on what you require, this is extremely important

How to revert to origin's master branch's version of file

I've faced same problem and came across to this thread but my problem was with upstream. Below git command worked for me.

Syntax

git checkout {remoteName}/{branch} -- {../path/file.js}

Example

git checkout upstream/develop -- public/js/index.js

C# Clear Session

In ASP.NET, when should I use Session.Clear() rather than Session.Abandon()?

Session.Abandon() destroys the session and the Session_OnEnd event is triggered.

Session.Clear() just removes all values (content) from the Object. The session with the same key is still alive.

So, if you use Session.Abandon(), you lose that specific session and the user will get a new session key. You could use it for example when the user logs out.

Use Session.Clear(), if you want that the user remaining in the same session (if you don't want him to relogin for example) and reset all his session specific data.

What is the difference between Session.Abandon() and Session.Clear()

Clear - Removes all keys and values from the session-state collection.

Abandon - removes all the objects stored in a Session. If you do not call the Abandon method explicitly, the server removes these objects and destroys the session when the session times out. It also raises events like Session_End.

Session.Clear can be compared to removing all books from the shelf, while Session.Abandon is more like throwing away the whole shelf.

...

Generally, in most cases you need to use Session.Clear. You can use Session.Abandon if you are sure the user is going to leave your site.

So back to the differences:

  • Abandon raises Session_End request.
  • Clear removes items immediately, Abandon does not.
  • Abandon releases the SessionState object and its items so it can garbage collected.
  • Clear keeps SessionState and resources associated with it.

Session.Clear() or Session.Abandon() ?

You use Session.Clear() when you don't want to end the session but rather just clear all the keys in the session and reinitialize the session.

Session.Clear() will not cause the Session_End eventhandler in your Global.asax file to execute.

But on the other hand Session.Abandon() will remove the session altogether and will execute Session_End eventhandler.

Session.Clear() is like removing books from the bookshelf

Session.Abandon() is like throwing the bookshelf itself.

Question

I check on some sessions if not equal null in the page load. if one of them equal null i wanna to clear all the sessions and redirect to the login page?

Answer

If you want the user to login again, use Session.Abandon.

How to get two or more commands together into a batch file

You can use the following command. The SET will set the input from the user console to the variable comment and then you can use that variable using %comment%

SET /P comment=Comment: 
echo %comment%
pause

Curl and PHP - how can I pass a json through curl by PUT,POST,GET

You can use this small library: https://github.com/ledfusion/php-rest-curl

Making a call is as simple as:

// GET
$result = RestCurl::get($URL, array('id' => 12345678));

// POST
$result = RestCurl::post($URL, array('name' => 'John'));

// PUT
$result = RestCurl::put($URL, array('$set' => array('lastName' => "Smith")));

// DELETE
$result = RestCurl::delete($URL); 

And for the $result variable:

  • $result['status'] is the HTTP response code
  • $result['data'] an array with the JSON response parsed
  • $result['header'] a string with the response headers

Hope it helps

Loading cross-domain endpoint with AJAX

I'm posting this in case someone faces the same problem I am facing right now. I've got a Zebra thermal printer, equipped with the ZebraNet print server, which offers a HTML-based user interface for editing multiple settings, seeing the printer's current status, etc. I need to get the status of the printer, which is displayed in one of those html pages, offered by the ZebraNet server and, for example, alert() a message to the user in the browser. This means that I have to get that html page in Javascript first. Although the printer is within the LAN of the user's PC, that Same Origin Policy is still staying firmly in my way. I tried JSONP, but the server returns html and I haven't found a way to modify its functionality (if I could, I would have already set the magic header Access-control-allow-origin: *). So I decided to write a small console app in C#. It has to be run as Admin to work properly, otherwise it trolls :D an exception. Here is some code:

// Create a listener.
        HttpListener listener = new HttpListener();
        // Add the prefixes.
        //foreach (string s in prefixes)
        //{
        //    listener.Prefixes.Add(s);
        //}
        listener.Prefixes.Add("http://*:1234/"); // accept connections from everywhere,
        //because the printer is accessible only within the LAN (no portforwarding)
        listener.Start();
        Console.WriteLine("Listening...");
        // Note: The GetContext method blocks while waiting for a request. 
        HttpListenerContext context;
        string urlForRequest = "";

        HttpWebRequest requestForPage = null;
        HttpWebResponse responseForPage = null;
        string responseForPageAsString = "";

        while (true)
        {
            context = listener.GetContext();
            HttpListenerRequest request = context.Request;
            urlForRequest = request.RawUrl.Substring(1, request.RawUrl.Length - 1); // remove the slash, which separates the portNumber from the arg sent
            Console.WriteLine(urlForRequest);

            //Request for the html page:
            requestForPage = (HttpWebRequest)WebRequest.Create(urlForRequest);
            responseForPage = (HttpWebResponse)requestForPage.GetResponse();
            responseForPageAsString = new StreamReader(responseForPage.GetResponseStream()).ReadToEnd();

            // Obtain a response object.
            HttpListenerResponse response = context.Response;
            // Send back the response.
            byte[] buffer = System.Text.Encoding.UTF8.GetBytes(responseForPageAsString);
            // Get a response stream and write the response to it.
            response.ContentLength64 = buffer.Length;
            response.AddHeader("Access-Control-Allow-Origin", "*"); // the magic header in action ;-D
            System.IO.Stream output = response.OutputStream;
            output.Write(buffer, 0, buffer.Length);
            // You must close the output stream.
            output.Close();
            //listener.Stop();

All the user needs to do is run that console app as Admin. I know it is way too ... frustrating and complicated, but it is sort of a workaround to the Domain Policy problem in case you cannot modify the server in any way.

edit: from js I make a simple ajax call:

$.ajax({
                type: 'POST',
                url: 'http://LAN_IP:1234/http://google.com',
                success: function (data) {
                    console.log("Success: " + data);
                },
                error: function (e) {
                    alert("Error: " + e);
                    console.log("Error: " + e);
                }
            });

The html of the requested page is returned and stored in the data variable.

Split (explode) pandas dataframe string entry to separate rows

I came up with a solution for dataframes with arbitrary numbers of columns (while still only separating one column's entries at a time).

def splitDataFrameList(df,target_column,separator):
    ''' df = dataframe to split,
    target_column = the column containing the values to split
    separator = the symbol used to perform the split

    returns: a dataframe with each entry for the target column separated, with each element moved into a new row. 
    The values in the other columns are duplicated across the newly divided rows.
    '''
    def splitListToRows(row,row_accumulator,target_column,separator):
        split_row = row[target_column].split(separator)
        for s in split_row:
            new_row = row.to_dict()
            new_row[target_column] = s
            row_accumulator.append(new_row)
    new_rows = []
    df.apply(splitListToRows,axis=1,args = (new_rows,target_column,separator))
    new_df = pandas.DataFrame(new_rows)
    return new_df

"Cannot allocate an object of abstract type" error

In C++ a class with at least one pure virtual function is called abstract class. You can not create objects of that class, but may only have pointers or references to it.

If you are deriving from an abstract class, then make sure you override and define all pure virtual functions for your class.

From your snippet Your class AliceUniversity seems to be an abstract class. It needs to override and define all the pure virtual functions of the classes Graduate and UniversityGraduate.

Pure virtual functions are the ones with = 0; at the end of declaration.

Example: virtual void doSomething() = 0;

For a specific answer, you will need to post the definition of the class for which you get the error and the classes from which that class is deriving.

Oracle SQL - DATE greater than statement

As your query string is a literal, and assuming your dates are properly stored as DATE you should use date literals:

SELECT * FROM OrderArchive
WHERE OrderDate <= DATE '2015-12-31'

If you want to use TO_DATE (because, for example, your query value is not a literal), I suggest you to explicitly set the NLS_DATE_LANGUAGE parameter as you are using US abbreviated month names. That way, it won't break on some localized Oracle Installation:

SELECT * FROM OrderArchive
WHERE OrderDate <= to_date('31 Dec 2014', 'DD MON YYYY',
                           'NLS_DATE_LANGUAGE = American');

MySQL - Meaning of "PRIMARY KEY", "UNIQUE KEY" and "KEY" when used together while creating a table

A key is just a normal index. A way over simplification is to think of it like a card catalog at a library. It points MySQL in the right direction.

A unique key is also used for improved searching speed, but it has the constraint that there can be no duplicated items (there are no two x and y where x is not y and x == y).

The manual explains it as follows:

A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an existing row. This constraint does not apply to NULL values except for the BDB storage engine. For other engines, a UNIQUE index permits multiple NULL values for columns that can contain NULL. If you specify a prefix value for a column in a UNIQUE index, the column values must be unique within the prefix.

A primary key is a 'special' unique key. It basically is a unique key, except that it's used to identify something.

The manual explains how indexes are used in general: here.

In MSSQL, the concepts are similar. There are indexes, unique constraints and primary keys.

Untested, but I believe the MSSQL equivalent is:

CREATE TABLE tmp (
  id int NOT NULL PRIMARY KEY IDENTITY,
  uid varchar(255) NOT NULL CONSTRAINT uid_unique UNIQUE,
  name varchar(255) NOT NULL,
  tag int NOT NULL DEFAULT 0,
  description varchar(255),
);

CREATE INDEX idx_name ON tmp (name);
CREATE INDEX idx_tag ON tmp (tag);

Edit: the code above is tested to be correct; however, I suspect that there's a much better syntax for doing it. Been a while since I've used SQL server, and apparently I've forgotten quite a bit :).

How can I reduce the waiting (ttfb) time

If you are using PHP, try using <?php flush(); ?> after </head> and before </body> or whatever section you want to output quickly (like the header or content). It will output the actually code without waiting for php to end. Don't use this function all the time, or the speed increase won't be noticable.

More info

Read Excel sheet in Powershell

There is the possibility of making something really more cool!

# Powershell 
$xl = new-object -ComObject excell.application
$doc=$xl.workbooks.open("Filepath")
$doc.Sheets.item(1).rows |
% { ($_.value2 | Select-Object -first 3 | Select-Object -last 2) -join "," }

Change the default base url for axios

  1. Create .env.development, .env.production files if not exists and add there your API endpoint, for example: VUE_APP_API_ENDPOINT ='http://localtest.me:8000'
  2. In main.js file, add this line after imports: axios.defaults.baseURL = process.env.VUE_APP_API_ENDPOINT

And that's it. Axios default base Url is replaced with build mode specific API endpoint. If you need specific baseURL for specific request, do it like this:

this.$axios({ url: 'items', baseURL: 'http://new-url.com' })

Getting activity from context in android

This method should be helpful..!

public Activity getActivityByContext(Context context){

if(context == null){
    return null;
    }

else if((context instanceof ContextWrapper) && (context instanceof Activity)){
        return (Activity) context;
    }

else if(context instanceof ContextWrapper){
        return getActivity(((ContextWrapper) context).getBaseContext());
    }

return null;

    }

I hope this helps.. Merry coding!

Conditionally formatting if multiple cells are blank (no numerics throughout spreadsheet )

enter image description here

How about just > Format only cells that contain - in the drop down box select Blanks

Generating HTML email body in C#

You can use the MailDefinition class.

This is how you use it:

MailDefinition md = new MailDefinition();
md.From = "[email protected]";
md.IsBodyHtml = true;
md.Subject = "Test of MailDefinition";

ListDictionary replacements = new ListDictionary();
replacements.Add("{name}", "Martin");
replacements.Add("{country}", "Denmark");

string body = "<div>Hello {name} You're from {country}.</div>";

MailMessage msg = md.CreateMailMessage("[email protected]", replacements, body, new System.Web.UI.Control());

Also, I've written a blog post on how to generate HTML e-mail body in C# using templates using the MailDefinition class.

How to override equals method in Java

Item 10: Obey the general contract when overriding equals

According to Effective Java, Overriding the equals method seems simple, but there are many ways to get it wrong, and consequences can be dire. The easiest way to avoid problems is not to override the equals method, in which case each instance of the class is equal only to itself. This is the right thing to do if any of the following conditions apply:

  • Each instance of the class is inherently unique. This is true for classes such as Thread that represent active entities rather than values. The equals implementation provided by Object has exactly the right behavior for these classes.

  • There is no need for the class to provide a “logical equality” test. For example, java.util.regex.Pattern could have overridden equals to check whether two Pattern instances represented exactly the same regular expression, but the designers didn’t think that clients would need or want this functionality. Under these circumstances, the equals implementation inherited from Object is ideal.

  • A superclass has already overridden equals, and the superclass behavior is appropriate for this class. For example, most Set implementations inherit their equals implementation from AbstractSet, List implementations from AbstractList, and Map implementations from AbstractMap.

  • The class is private or package-private, and you are certain that its equals method will never be invoked. If you are extremely risk-averse, you can override the equals method to ensure that it isn’t invoked accidentally:

The equals method implements an equivalence relation. It has these properties:

  • Reflexive: For any non-null reference value x, x.equals(x) must return true.

  • Symmetric: For any non-null reference values x and y, x.equals(y) must return true if and only if y.equals(x) returns true.

  • Transitive: For any non-null reference values x, y, z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) must return true.

  • Consistent: For any non-null reference values x and y, multiple invocations of x.equals(y) must consistently return true or consistently return false, provided no information used in equals comparisons is modified.

  • For any non-null reference value x, x.equals(null) must return false.

Here’s a recipe for a high-quality equals method:

  1. Use the == operator to check if the argument is a reference to this object. If so, return true. This is just a performance optimization but one that is worth doing if the comparison is potentially expensive.

  2. Use the instanceof operator to check if the argument has the correct type. If not, return false. Typically, the correct type is the class in which the method occurs. Occasionally, it is some interface implemented by this class. Use an interface if the class implements an interface that refines the equals contract to permit comparisons across classes that implement the interface. Collection interfaces such as Set, List, Map, and Map.Entry have this property.

  3. Cast the argument to the correct type. Because this cast was preceded by an instanceof test, it is guaranteed to succeed.

  4. For each “significant” field in the class, check if that field of the argument matches the corresponding field of this object. If all these tests succeed, return true; otherwise, return false. If the type in Step 2 is an interface, you must access the argument’s fields via interface methods; if the type is a class, you may be able to access the fields directly, depending on their accessibility.

  5. For primitive fields whose type is not float or double, use the == operator for comparisons; for object reference fields, call the equals method recursively; for float fields, use the static Float.compare(float, float) method; and for double fields, use Double.compare(double, double). The special treatment of float and double fields is made necessary by the existence of Float.NaN, -0.0f and the analogous double values; While you could compare float and double fields with the static methods Float.equals and Double.equals, this would entail autoboxing on every comparison, which would have poor performance. For array fields, apply these guidelines to each element. If every element in an array field is significant, use one of the Arrays.equals methods.

  6. Some object reference fields may legitimately contain null. To avoid the possibility of a NullPointerException, check such fields for equality using the static method Objects.equals(Object, Object).

    // Class with a typical equals method
    
    public final class PhoneNumber {
    
        private final short areaCode, prefix, lineNum;
    
        public PhoneNumber(int areaCode, int prefix, int lineNum) {
    
            this.areaCode = rangeCheck(areaCode,  999, "area code");
    
            this.prefix   = rangeCheck(prefix,    999, "prefix");
    
            this.lineNum  = rangeCheck(lineNum,  9999, "line num");
    
        }
    
        private static short rangeCheck(int val, int max, String arg) {
    
            if (val < 0 || val > max)
    
               throw new IllegalArgumentException(arg + ": " + val);
    
            return (short) val;
    
        }
    
        @Override public boolean equals(Object o) {
            if (o == this)
                return true;
            if (!(o instanceof PhoneNumber))
                return false;
            PhoneNumber pn = (PhoneNumber)o;
            return pn.lineNum == lineNum && pn.prefix == prefix
                    && pn.areaCode == areaCode;
        }
        ... // Remainder omitted
    
    }
    

Placeholder in IE9

I know I'm late but I found a solution inserting in the head the tag:

_x000D_
_x000D_
<meta http-equiv="X-UA-Compatible" content="IE=edge"/> <!--FIX jQuery INTERNET EXPLORER-->
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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.

Printing an int list in a single line python3

# Print In One Line Python

print('Enter Value')

n = int(input())

print(*range(1, n+1), sep="")

DISTINCT clause with WHERE

select t1.*
from YourTable as t1
  inner join
    (select email
     from YourTable
     group by email
     having count(email) = 1 ) as t2
    on t1.email = t2.email   

String concatenation in Ruby

Concatenation you say? How about #concat method then?

a = 'foo'
a.object_id #=> some number
a.concat 'bar' #=> foobar
a.object_id #=> same as before -- string a remains the same object

In all fairness, concat is aliased as <<.

MySQL FULL JOIN?

SELECT  p.LastName, p.FirstName, o.OrderNo
FROM    persons AS p
LEFT JOIN
        orders AS o
ON      o.orderNo = p.p_id
UNION ALL
SELECT  NULL, NULL, orderNo
FROM    orders
WHERE   orderNo NOT IN
        (
        SELECT  p_id
        FROM    persons
        )

smtpclient " failure sending mail"

Five years later (I hope this developer isn't still waiting for a fix to this..)

I had the same issue, caused by the same error: I was declaring the SmtpClient inside the loop.

The fix is simple - declare it once, outside the loop...

MailAddress mail = null;
SmtpClient client = new SmtpClient();
client.Port = 25;
client.EnableSsl = false;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.UseDefaultCredentials = true;
client.Host = smtpAddress;       //  Enter your company's email server here!

for(int i = 0; i < number ; i++)
{
    mail = new MailMessage(iMail.from, iMail.to);
    mail.Subject = iMail.sub;
    mail.Body = iMail.body;
    mail.IsBodyHtml = true;
    mail.Priority = MailPriority.Normal;
    mail.Sender = from;
    client.Send(mail);
}
mail.Dispose();
client.Dispose();

Compile Views in ASP.NET MVC

Next release of ASP.NET MVC (available in January or so) should have MSBuild task that compiles views, so you might want to wait.

See announcement

Position an element relative to its container

You are right that CSS positioning is the way to go. Here's a quick run down:

position: relative will layout an element relative to itself. In other words, the elements is laid out in normal flow, then it is removed from normal flow and offset by whatever values you have specified (top, right, bottom, left). It's important to note that because it's removed from flow, other elements around it will not shift with it (use negative margins instead if you want this behaviour).

However, you're most likely interested in position: absolute which will position an element relative to a container. By default, the container is the browser window, but if a parent element either has position: relative or position: absolute set on it, then it will act as the parent for positioning coordinates for its children.

To demonstrate:

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#container {_x000D_
  position: relative;_x000D_
  border: 1px solid red;_x000D_
  height: 100px;_x000D_
}_x000D_
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#box {_x000D_
  position: absolute;_x000D_
  top: 50px;_x000D_
  left: 20px;_x000D_
}
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<div id="container">_x000D_
  <div id="box">absolute</div>_x000D_
</div>
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In that example, the top left corner of #box would be 100px down and 50px left of the top left corner of #container. If #container did not have position: relative set, the coordinates of #box would be relative to the top left corner of the browser view port.

Efficiently updating database using SQLAlchemy ORM

If it is because of the overhead in terms of creating objects, then it probably can't be sped up at all with SA.

If it is because it is loading up related objects, then you might be able to do something with lazy loading. Are there lots of objects being created due to references? (IE, getting a Company object also gets all of the related People objects).

SQL Server Format Date DD.MM.YYYY HH:MM:SS

CONVERT(VARCHAR,GETDATE(),120)

How to check whether a str(variable) is empty or not?

Empty strings are False by default:

>>> if not "":
...     print("empty")
...
empty

How to apply multiple transforms in CSS?

Just start from there that in CSS, if you repeat 2 values or more, always last one gets applied, unless using !important tag, but at the same time avoid using !important as much as you can, so in your case that's the problem, so the second transform override the first one in this case...

So how you can do what you want then?...

Don't worry, transform accepts multiple values at the same time... So this code below will work:

li:nth-child(2) {
  transform: rotate(15deg) translate(-20px, 0px); //multiple
}

If you like to play around with transform run the iframe from MDN below:

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<iframe src="https://interactive-examples.mdn.mozilla.net/pages/css/transform.html" class="interactive  " width="100%" frameborder="0" height="250"></iframe>
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Look at the link below for more info:

<< CSS transform >>

How to secure an ASP.NET Web API

I would suggest starting with the most straightforward solutions first - maybe simple HTTP Basic Authentication + HTTPS is enough in your scenario.

If not (for example you cannot use https, or need more complex key management), you may have a look at HMAC-based solutions as suggested by others. A good example of such API would be Amazon S3 (http://s3.amazonaws.com/doc/s3-developer-guide/RESTAuthentication.html)

I wrote a blog post about HMAC based authentication in ASP.NET Web API. It discusses both Web API service and Web API client and the code is available on bitbucket. http://www.piotrwalat.net/hmac-authentication-in-asp-net-web-api/

Here is a post about Basic Authentication in Web API: http://www.piotrwalat.net/basic-http-authentication-in-asp-net-web-api-using-message-handlers/

Remember that if you are going to provide an API to 3rd parties, you will also most likely be responsible for delivering client libraries. Basic authentication has a significant advantage here as it is supported on most programming platforms out of the box. HMAC, on the other hand, is not that standardized and will require custom implementation. These should be relatively straightforward but still require work.

PS. There is also an option to use HTTPS + certificates. http://www.piotrwalat.net/client-certificate-authentication-in-asp-net-web-api-and-windows-store-apps/

MySQL Trigger after update only if row has changed

In here if there any row affect with new insertion Then it will update on different table in the database.

DELIMITER $$

CREATE TRIGGER "give trigger name" AFTER INSERT ON "table name" 
FOR EACH ROW
BEGIN
    INSERT INTO "give table name you want to add the new insertion on previously given table" (id,name,age) VALUES (10,"sumith",24);
END;
$$
DELIMITER ;

Email & Phone Validation in Swift

Swift 4 & Swift 5:

func isValidPhone(phone: String) -> Bool {
        let phoneRegex = "^[0-9+]{0,1}+[0-9]{5,16}$"
        let phoneTest = NSPredicate(format: "SELF MATCHES %@", phoneRegex)
        return phoneTest.evaluate(with: phone)
    }

func isValidEmail(email: String) -> Bool {
        let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
        let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
        return emailTest.evaluate(with: email)
    }

How to set IntelliJ IDEA Project SDK

For IntelliJ IDEA 2017.2 I did the following to fix this issue: Go to your project structure enter image description here Now go to SDKs under platform settings and click the green add button. Add your JDK path. In my case it was this path C:\Program Files\Java\jdk1.8.0_144 enter image description here Now Just go Project under Project settings and select the project SDK. enter image description here

How to display JavaScript variables in a HTML page without document.write

innerHTML is fine and still valid. Use it all the time on projects big and small. I just flipped to an open tab in my IDE and there was one right there.

 document.getElementById("data-progress").innerHTML = "<img src='../images/loading.gif'/>";

Not much has changed in js + dom manipulation since 2005, other than the addition of more libraries. You can easily set other properties such as

   uploadElement.style.width = "100%";

Using Python's os.path, how do I go up one directory?

Personally, I'd go for the function approach

def get_parent_dir(directory):
    import os
    return os.path.dirname(directory)

current_dirs_parent = get_parent_dir(os.getcwd())

How to get the focused element with jQuery?

I've tested two ways in Firefox, Chrome, IE9 and Safari.

(1). $(document.activeElement) works as expected in Firefox, Chrome and Safari.

(2). $(':focus') works as expected in Firefox and Safari.

I moved into the mouse to input 'name' and pressed Enter on keyboard, then I tried to get the focused element.

(1). $(document.activeElement) returns the input:text:name as expected in Firefox, Chrome and Safari, but it returns input:submit:addPassword in IE9

(2). $(':focus') returns input:text:name as expected in Firefox and Safari, but nothing in IE

<form action="">
    <div id="block-1" class="border">
        <h4>block-1</h4>
        <input type="text" value="enter name here" name="name"/>            
        <input type="button" value="Add name" name="addName"/>
    </div>
    <div id="block-2" class="border">
        <h4>block-2</h4>
        <input type="text" value="enter password here" name="password"/>            
        <input type="submit" value="Add password" name="addPassword"/>
    </div>
</form>

Compiled vs. Interpreted Languages

A compiler and an interpreter do the same job: translating a programming language to another pgoramming language, usually closer to the hardware, often direct executable machine code.

Traditionally, "compiled" means that this translation happens all in one go, is done by a developer, and the resulting executable is distributed to users. Pure example: C++. Compilation usually takes pretty long and tries to do lots of expensive optmization so that the resulting executable runs faster. End users don't have the tools and knowledge to compile stuff themselves, and the executable often has to run on a variety of hardware, so you can't do many hardware-specific optimizations. During development, the separate compilation step means a longer feedback cycle.

Traditionally, "interpreted" means that the translation happens "on the fly", when the user wants to run the program. Pure example: vanilla PHP. A naive interpreter has to parse and translate every piece of code every time it runs, which makes it very slow. It can't do complex, costly optimizations because they'd take longer than the time saved in execution. But it can fully use the capabilities of the hardware it runs on. The lack of a separrate compilation step reduces feedback time during development.

But nowadays "compiled vs. interpreted" is not a black-or-white issue, there are shades in between. Naive, simple interpreters are pretty much extinct. Many languages use a two-step process where the high-level code is translated to a platform-independant bytecode (which is much faster to interpret). Then you have "just in time compilers" which compile code at most once per program run, sometimes cache results, and even intelligently decide to interpret code that's run rarely, and do powerful optimizations for code that runs a lot. During development, debuggers are capable of switching code inside a running program even for traditionally compiled languages.

How does Git handle symbolic links?

You can find out what Git does with a file by seeing what it does when you add it to the index. The index is like a pre-commit. With the index committed, you can use git checkout to bring everything that was in the index back into the working directory. So, what does Git do when you add a symbolic link to the index?

To find out, first, make a symbolic link:

$ ln -s /path/referenced/by/symlink symlink

Git doesn't know about this file yet. git ls-files lets you inspect your index (-s prints stat-like output):

$ git ls-files -s ./symlink
[nothing]

Now, add the contents of the symbolic link to the Git object store by adding it to the index. When you add a file to the index, Git stores its contents in the Git object store.

$ git add ./symlink

So, what was added?

$ git ls-files -s ./symlink
120000 1596f9db1b9610f238b78dd168ae33faa2dec15c 0       symlink

The hash is a reference to the packed object that was created in the Git object store. You can examine this object if you look in .git/objects/15/96f9db1b9610f238b78dd168ae33faa2dec15c in the root of your repository. This is the file that Git stores in the repository, that you can later check out. If you examine this file, you'll see it is very small. It does not store the contents of the linked file. To confirm this, print the contents of the packed repository object with git cat-file:

$ git cat-file -p 1596f9db1b9610f238b78dd168ae33faa2dec15c
/path/referenced/by/symlink

(Note 120000 is the mode listed in ls-files output. It would be something like 100644 for a regular file.)

But what does Git do with this object when you check it out from the repository and into your filesystem? It depends on the core.symlinks config. From man git-config:

core.symlinks

If false, symbolic links are checked out as small plain files that contain the link text.

So, with a symbolic link in the repository, upon checkout you either get a text file with a reference to a full filesystem path, or a proper symbolic link, depending on the value of the core.symlinks config.

Either way, the data referenced by the symlink is not stored in the repository.

Carry Flag, Auxiliary Flag and Overflow Flag in Assembly

Carry Flag is a flag set when:

a) two unsigned numbers were added and the result is larger than "capacity" of register where it is saved. Ex: we wanna add two 8 bit numbers and save result in 8 bit register. In your example: 255 + 9 = 264 which is more that 8 bit register can store. So the value "8" will be saved there (264 & 255 = 8) and CF flag will be set.

b) two unsigned numbers were subtracted and we subtracted the bigger one from the smaller one. Ex: 1-2 will give you 255 in result and CF flag will be set.

Auxiliary Flag is used as CF but when working with BCD. So AF will be set when we have overflow or underflow on in BCD calculations. For example: considering 8 bit ALU unit, Auxiliary flag is set when there is carry from 3rd bit to 4th bit i.e. carry from lower nibble to higher nibble. (Wiki link)

Overflow Flag is used as CF but when we work on signed numbers. Ex we wanna add two 8 bit signed numbers: 127 + 2. the result is 129 but it is too much for 8bit signed number, so OF will be set. Similar when the result is too small like -128 - 1 = -129 which is out of scope for 8 bit signed numbers.

You can read more about flags on wikipedia

PDF Parsing Using Python - extracting formatted and plain texts

You can also take a look at PDFMiner (or for older versions of Python see PDFMiner and PDFMiner).

A particular feature of interest in PDFMiner is that you can control how it regroups text parts when extracting them. You do this by specifying the space between lines, words, characters, etc. So, maybe by tweaking this you can achieve what you want (that depends of the variability of your documents). PDFMiner can also give you the location of the text in the page, it can extract data by Object ID and other stuff. So dig in PDFMiner and be creative!

But your problem is really not an easy one to solve because, in a PDF, the text is not continuous, but made from a lot of small groups of characters positioned absolutely in the page. The focus of PDF is to keep the layout intact. It's not content oriented but presentation oriented.

PHP parse/syntax errors; and how to solve them

Unexpected T_IS_EQUAL
Unexpected T_IS_GREATER_OR_EQUAL
Unexpected T_IS_IDENTICAL
Unexpected T_IS_NOT_EQUAL
Unexpected T_IS_NOT_IDENTICAL
Unexpected T_IS_SMALLER_OR_EQUAL
Unexpected <
Unexpected >

Comparison operators such as ==, >=, ===, !=, <>, !== and <= or < and > mostly should be used just in expressions, such as if expressions. If the parser complains about them, then it often means incorrect paring or mismatched ( ) parens around them.

  1. Parens grouping

    In particular for if statements with multiple comparisons you must take care to correctly count opening and closing parenthesis:

                            ?
    if (($foo < 7) && $bar) > 5 || $baz < 9) { ... }
                          ?
    

    Here the if condition here was already terminated by the )

    Once your comparisons become sufficiently complex it often helps to split it up into multiple and nested if constructs rather.

  2. isset() mashed with comparing

    A common newcomer is pitfal is trying to combine isset() or empty() with comparisons:

                            ?
    if (empty($_POST["var"] == 1)) {
    

    Or even:

                        ?
    if (isset($variable !== "value")) {
    

    This doesn't make sense to PHP, because isset and empty are language constructs that only accept variable names. It doesn't make sense to compare the result either, because the output is only/already a boolean.

  3. Confusing >= greater-or-equal with => array operator

    Both operators look somewhat similar, so they sometimes get mixed up:

             ?
    if ($var => 5) { ... }
    

    You only need to remember that this comparison operator is called "greater than or equal" to get it right.

    See also: If statement structure in PHP

  4. Nothing to compare against

    You also can't combine two comparisons if they pertain the same variable name:

                     ?
    if ($xyz > 5 and < 100)
    

    PHP can't deduce that you meant to compare the initial variable again. Expressions are usually paired according to operator precedence, so by the time the < is seen, there'd be only a boolean result left from the original variable.

    See also: unexpected T_IS_SMALLER_OR_EQUAL

  5. Comparison chains

    You can't compare against a variable with a row of operators:

                      ?
     $reult = (5 < $x < 10);
    

    This has to be broken up into two comparisons, each against $x.

    This is actually more a case of blacklisted expressions (due to equivalent operator associativity). It's syntactically valid in a few C-style languages, but PHP wouldn't interpret it as expected comparison chain either.

  6. Unexpected >
    Unexpected <

    The greater than > or less than < operators don't have a custom T_XXX tokenizer name. And while they can be misplaced like all they others, you more often see the parser complain about them for misquoted strings and mashed HTML:

                            ?
    print "<a href='z">Hello</a>";
                     ?
    

    This amounts to a string "<a href='z" being compared > to a literal constant Hello and then another < comparison. Or that's at least how PHP sees it. The actual cause and syntax mistake was the premature string " termination.

    It's also not possible to nest PHP start tags:

    <?php echo <?php my_func(); ?>
               ?
    

See also: