Programs & Examples On #Jpl

A Java Interface to Prolog.

Saving binary data as file using JavaScript from a browser

This is possible if the browser supports the download property in anchor elements.

var sampleBytes = new Int8Array(4096);

var saveByteArray = (function () {
    var a = document.createElement("a");
    document.body.appendChild(a);
    a.style = "display: none";
    return function (data, name) {
        var blob = new Blob(data, {type: "octet/stream"}),
            url = window.URL.createObjectURL(blob);
        a.href = url;
        a.download = name;
        a.click();
        window.URL.revokeObjectURL(url);
    };
}());

saveByteArray([sampleBytes], 'example.txt');


JSFiddle: http://jsfiddle.net/VB59f/2

Using curl POST with variables defined in bash script functions

Curl can post binary data from a file so I have been using process substitution and taking advantage of file descriptors whenever I need to post something nasty with curl and still want access to the vars in the current shell. Something like:

curl "http://localhost:8080" \
-H "Accept: application/json" \
-H "Content-Type:application/json" \
--data @<(cat <<EOF
{
  "me": "$USER",
  "something": $(date +%s)
  }
EOF
)

This winds up looking like --data @/dev/fd/<some number> which just gets processed like a normal file. Anyway if you wanna see it work locally just run nc -l 8080 first and in a different shell fire off the above command. You will see something like:

POST / HTTP/1.1
Host: localhost:8080
User-Agent: curl/7.43.0
Accept: application/json
Content-Type:application/json
Content-Length: 43

{  "me": "username",  "something": 1465057519  }

As you can see you can call subshells and whatnot as well as reference vars in the heredoc. Happy hacking hope this helps with the '"'"'""""'''""''.

Excel VBA Code: Compile Error in x64 Version ('PtrSafe' attribute required)

I'm quite sure you won't get this 32Bit DLL working in Office 64Bit. The DLL needs to be updated by the author to be compatible with 64Bit versions of Office.

The code changes you have found and supplied in the question are used to convert calls to APIs that have already been rewritten for Office 64Bit. (Most Windows APIs have been updated.)

From: http://technet.microsoft.com/en-us/library/ee681792.aspx:

"ActiveX controls and add-in (COM) DLLs (dynamic link libraries) that were written for 32-bit Office will not work in a 64-bit process."

Edit: Further to your comment, I've tried the 64Bit DLL version on Win 8 64Bit with Office 2010 64Bit. Since you are using User Defined Functions called from the Excel worksheet you are not able to see the error thrown by Excel and just end up with the #VALUE returned.

If we create a custom procedure within VBA and try one of the DLL functions we see the exact error thrown. I tried a simple function of swe_day_of_week which just has a time as an input and I get the error Run-time error '48' File not found: swedll32.dll.

Now I have the 64Bit DLL you supplied in the correct locations so it should be found which suggests it has dependencies which cannot be located as per https://stackoverflow.com/a/8607250/1733206

I've got all the .NET frameworks installed which would be my first guess, so without further information from the author it might be difficult to find the problem.

Edit2: And after a bit more investigating it appears the 64Bit version you have supplied is actually a 32Bit version. Hence the error message on the 64Bit Office. You can check this by trying to access the '64Bit' version in Office 32Bit.

what does this mean ? image/png;base64?

They serve the actual image inside CSS so there will be less HTTP requests per page.

What does (function($) {})(jQuery); mean?

Firstly, a code block that looks like (function(){})() is merely a function that is executed in place. Let's break it down a little.

1. (
2.    function(){}
3. )
4. ()

Line 2 is a plain function, wrapped in parenthesis to tell the runtime to return the function to the parent scope, once it's returned the function is executed using line 4, maybe reading through these steps will help

1. function(){ .. }
2. (1)
3. 2()

You can see that 1 is the declaration, 2 is returning the function and 3 is just executing the function.

An example of how it would be used.

(function(doc){

   doc.location = '/';

})(document);//This is passed into the function above

As for the other questions about the plugins:

Type 1: This is not a actually a plugin, it's an object passed as a function, as plugins tend to be functions.

Type 2: This is again not a plugin as it does not extend the $.fn object. It's just an extenstion of the jQuery core, although the outcome is the same. This is if you want to add traversing functions such as toArray and so on.

Type 3: This is the best method to add a plugin, the extended prototype of jQuery takes an object holding your plugin name and function and adds it to the plugin library for you.

Content Security Policy "data" not working for base64 Images in Chrome 28

According to the grammar in the CSP spec, you need to specify schemes as scheme:, not just scheme. So, you need to change the image source directive to:

img-src 'self' data:;

Why won't bundler install JSON gem?

I installed the latest version of json:

gem install json

Then deleted the line json(1.8.1) from the Gemfile.lock and did a

bundle install

And then the Gemfile.lock file uses json(1.8.3) without erros

Spring Boot REST service exception handling

New answer (2016-04-20)

Using Spring Boot 1.3.1.RELEASE

New Step 1 - It is easy and less intrusive to add the following properties to the application.properties:

spring.mvc.throw-exception-if-no-handler-found=true
spring.resources.add-mappings=false

Much easier than modifying the existing DispatcherServlet instance (as below)! - JO'

If working with a full RESTful Application, it is very important to disable the automatic mapping of static resources since if you are using Spring Boot's default configuration for handling static resources then the resource handler will be handling the request (it's ordered last and mapped to /** which means that it picks up any requests that haven't been handled by any other handler in the application) so the dispatcher servlet doesn't get a chance to throw an exception.


New Answer (2015-12-04)

Using Spring Boot 1.2.7.RELEASE

New Step 1 - I found a much less intrusive way of setting the "throExceptionIfNoHandlerFound" flag. Replace the DispatcherServlet replacement code below (Step 1) with this in your application initialization class:

@ComponentScan()
@EnableAutoConfiguration
public class MyApplication extends SpringBootServletInitializer {
    private static Logger LOG = LoggerFactory.getLogger(MyApplication.class);
    public static void main(String[] args) {
        ApplicationContext ctx = SpringApplication.run(MyApplication.class, args);
        DispatcherServlet dispatcherServlet = (DispatcherServlet)ctx.getBean("dispatcherServlet");
        dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);
    }

In this case, we're setting the flag on the existing DispatcherServlet, which preserves any auto-configuration by the Spring Boot framework.

One more thing I've found - the @EnableWebMvc annotation is deadly to Spring Boot. Yes, that annotation enables things like being able to catch all the controller exceptions as described below, but it also kills a LOT of the helpful auto-configuration that Spring Boot would normally provide. Use that annotation with extreme caution when you use Spring Boot.


Original Answer:

After a lot more research and following up on the solutions posted here (thanks for the help!) and no small amount of runtime tracing into the Spring code, I finally found a configuration that will handle all Exceptions (not Errors, but read on) including 404s.

Step 1 - tell SpringBoot to stop using MVC for "handler not found" situations. We want Spring to throw an exception instead of returning to the client a view redirect to "/error". To do this, you need to have an entry in one of your configuration classes:

// NEW CODE ABOVE REPLACES THIS! (2015-12-04)
@Configuration
public class MyAppConfig {
    @Bean  // Magic entry 
    public DispatcherServlet dispatcherServlet() {
        DispatcherServlet ds = new DispatcherServlet();
        ds.setThrowExceptionIfNoHandlerFound(true);
        return ds;
    }
}

The downside of this is that it replaces the default dispatcher servlet. This hasn't been a problem for us yet, with no side effects or execution problems showing up. If you're going to do anything else with the dispatcher servlet for other reasons, this is the place to do them.

Step 2 - Now that spring boot will throw an exception when no handler is found, that exception can be handled with any others in a unified exception handler:

@EnableWebMvc
@ControllerAdvice
public class ServiceExceptionHandler extends ResponseEntityExceptionHandler {

    @ExceptionHandler(Throwable.class)
    @ResponseBody
    ResponseEntity<Object> handleControllerException(HttpServletRequest req, Throwable ex) {
        ErrorResponse errorResponse = new ErrorResponse(ex);
        if(ex instanceof ServiceException) {
            errorResponse.setDetails(((ServiceException)ex).getDetails());
        }
        if(ex instanceof ServiceHttpException) {
            return new ResponseEntity<Object>(errorResponse,((ServiceHttpException)ex).getStatus());
        } else {
            return new ResponseEntity<Object>(errorResponse,HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }

    @Override
    protected ResponseEntity<Object> handleNoHandlerFoundException(NoHandlerFoundException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
        Map<String,String> responseBody = new HashMap<>();
        responseBody.put("path",request.getContextPath());
        responseBody.put("message","The URL you have reached is not in service at this time (404).");
        return new ResponseEntity<Object>(responseBody,HttpStatus.NOT_FOUND);
    }
    ...
}

Keep in mind that I think the "@EnableWebMvc" annotation is significant here. It seems that none of this works without it. And that's it - your Spring boot app will now catch all exceptions, including 404s, in the above handler class and you may do with them as you please.

One last point - there doesn't seem to be a way to get this to catch thrown Errors. I have a wacky idea of using aspects to catch errors and turn them into Exceptions that the above code can then deal with, but I have not yet had time to actually try implementing that. Hope this helps someone.

Any comments/corrections/enhancements will be appreciated.

PHP Warning: PHP Startup: Unable to load dynamic library

In my case I got this error because I downloaded a thread-safe version of the dll (infixed with -ts-), but my php installation of php was a non-thread-safe (infixed with -nts-). Downloading the right version of the dll, exactly matching my php installation version fixed the issue.

Android DialogFragment vs Dialog

DialogFragment comes with the power of a dialog and a Fragment. Basically all the lifecycle events are managed very well with DialogFragment automatically, like change in screen configuration etc.

ASP.NET custom error page - Server.GetLastError() is null

This related to these 2 topics below, I want get both GetHtmlErrorMessage and Session on Error page.

Session is null after ResponseRewrite

Why is HttpContext.Session null when redirectMode = ResponseRewrite

I tried and see solution which no need Server.Transfer() or Response.Redirect()

First: remove ResponseRewrite in web.config

Web.config

<customErrors defaultRedirect="errorHandler.aspx" mode="On" />

Then Global.asax

    void Application_Error(object sender, EventArgs e)
    {
         if(Context.IsCustomErrorEnabled)
         {     
            Exception ex = Server.GetLastError();
            Application["TheException"] = ex; //store the error for later
         }
    }

Then errorHandler.aspx.cs

        protected void Page_Load(object sender, EventArgs e)
            {       
                string htmlErrorMessage = string.Empty ;
                Exception ex = (Exception)Application["TheException"];
                string yourSessionValue = HttpContext.Current.Session["YourSessionId"].ToString();

                //continue with ex to get htmlErrorMessage 
                if(ex.GetHtmlErrorMessage() != null){              
                    htmlErrorMessage = ex.GetHtmlErrorMessage();
                }   
                // continue your code
            }

For references

http://www.developer.com/net/asp/article.php/3299641/ServerTransfer-Vs-ResponseRedirect.htm

c#: getter/setter

These are called auto properties.

http://msdn.microsoft.com/en-us/library/bb384054.aspx

Functionally (and in terms of the compiled IL), they are the same as properties with backing fields.

JavaScript console.log causes error: "Synchronous XMLHttpRequest on the main thread is deprecated..."

For me, the problem was that in an OK request, I expected the ajax response to be a well formatted HTML string such as a table, but in this case, the server was experiencing a problem with the request, redirecting to an error page, and was therefore returning back the HTML code of the error page (which had a <script tag somewhere. I console logged the ajax response and that's when I realized it was not what I was expecting, then proceeded to do my debugging.

How to scroll to an element in jQuery?

For my problem this code worked, I had to navigate to an anchor tag on page load :

$(window).scrollTop($('a#captchaAnchor').position().top);

For that matter you can use this on any element, not just an anchor tag.

How to use unicode characters in Windows command line?

For a similar problem, (my problem was to show UTF-8 characters from MySQL on a command prompt),

I solved it like this:

  1. I changed the font of command prompt to Lucida Console. (This step must be irrelevant for your situation. It has to do only with what you see on the screen and not with what is really the character).

  2. I changed the codepage to Windows-1253. You do this on the command prompt by "chcp 1253". It worked for my case where I wanted to see UTF-8.

WCF Error "This could be due to the fact that the server certificate is not configured properly with HTTP.SYS in the HTTPS case"

After a lot of searching and taking the lord's name in vain i finally got it.I have installed TLS 1.2 on the Server where my wcf service is running.My client was configured correctly but the it was built on .NET 4.5.1 whereas the wcf was on .NET 4.6.1. Both client and server must be at the same .NET Version if you are using TLS 1.2. I hope it helps someone someday:-)

diff current working copy of a file with another branch's committed copy

To see local changes compare to your current branch

git diff .

To see local changed compare to any other existing branch

git diff <branch-name> .

To see changes of a particular file

git diff <branch-name> -- <file-path>

Make sure you run git fetch at the beginning.

Setting a WebRequest's body data

Update

See my other SO answer.


Original

var request = (HttpWebRequest)WebRequest.Create("https://example.com/endpoint");

string stringData = ""; // place body here
var data = Encoding.Default.GetBytes(stringData); // note: choose appropriate encoding

request.Method = "PUT";
request.ContentType = ""; // place MIME type here
request.ContentLength = data.Length;

var newStream = request.GetRequestStream(); // get a ref to the request body so it can be modified
newStream.Write(data, 0, data.Length);
newStream.Close();

Error: unmappable character for encoding UTF8 during maven compilation

I too faced a similar issue and my resolution was different. I went to the line of code mentioned and traversed to the character (For SpanishTest.java[31, 81], go to 31st line and 81th character including spaces). I observed an apostrophe in comment which was causing the issue. Though not a mistake, the maven compiler reports issue and in my case it was possible to remove maven's 'illegal' character.. lol.

Save and retrieve image (binary) from SQL Server using Entity Framework 6

Convert the image to a byte[] and store that in the database.


Add this column to your model:

public byte[] Content { get; set; }

Then convert your image to a byte array and store that like you would any other data:

public byte[] ImageToByteArray(System.Drawing.Image imageIn)
{
    using(var ms = new MemoryStream())
    {
        imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);

        return ms.ToArray();
    }
}

public Image ByteArrayToImage(byte[] byteArrayIn)
{
     using(var ms = new MemoryStream(byteArrayIn))
     {
         var returnImage = Image.FromStream(ms);

         return returnImage;
     }
}

Source: Fastest way to convert Image to Byte array

var image = new ImageEntity()
{
   Content = ImageToByteArray(image)
};

_context.Images.Add(image);
_context.SaveChanges();

When you want to get the image back, get the byte array from the database and use the ByteArrayToImage and do what you wish with the Image

This stops working when the byte[] gets to big. It will work for files under 100Mb

Disabling Minimize & Maximize On WinForm?

you can simply disable maximize inside form constructor.

 public Form1(){
     InitializeComponent();
     MaximizeBox = false;
 }

to minimize when closing.

private void Form1_FormClosing(Object sender, FormClosingEventArgs e) {
    e.Cancel = true;
    WindowState = FormWindowState.Minimized;
}

Binding multiple events to a listener (without JQuery)?

I have a simpler solution for you:

window.onload = window.onresize = (event) => {
    //Your Code Here
}

I've tested this an it works great, on the plus side it's compact and uncomplicated like the other examples here.

How to convert an array into an object using stdClass()

One of the easiest solution is

$objectData = (object) $arrayData

Convert XmlDocument to String

" is shown as \" in the debugger, but the data is correct in the string, and you don't need to replace anything. Try to dump your string to a file and you will note that the string is correct.

The definitive guide to form-based website authentication

Definitive Article

Sending credentials

The only practical way to send credentials 100% securely is by using SSL. Using JavaScript to hash the password is not safe. Common pitfalls for client-side password hashing:

  • If the connection between the client and server is unencrypted, everything you do is vulnerable to man-in-the-middle attacks. An attacker could replace the incoming javascript to break the hashing or send all credentials to their server, they could listen to client responses and impersonate the users perfectly, etc. etc. SSL with trusted Certificate Authorities is designed to prevent MitM attacks.
  • The hashed password received by the server is less secure if you don't do additional, redundant work on the server.

There's another secure method called SRP, but it's patented (although it is freely licensed) and there are few good implementations available.

Storing passwords

Don't ever store passwords as plaintext in the database. Not even if you don't care about the security of your own site. Assume that some of your users will reuse the password of their online bank account. So, store the hashed password, and throw away the original. And make sure the password doesn't show up in access logs or application logs. OWASP recommends the use of Argon2 as your first choice for new applications. If this is not available, PBKDF2 or scrypt should be used instead. And finally if none of the above are available, use bcrypt.

Hashes by themselves are also insecure. For instance, identical passwords mean identical hashes--this makes hash lookup tables an effective way of cracking lots of passwords at once. Instead, store the salted hash. A salt is a string appended to the password prior to hashing - use a different (random) salt per user. The salt is a public value, so you can store them with the hash in the database. See here for more on this.

This means that you can't send the user their forgotten passwords (because you only have the hash). Don't reset the user's password unless you have authenticated the user (users must prove that they are able to read emails sent to the stored (and validated) email address.)

Security questions

Security questions are insecure - avoid using them. Why? Anything a security question does, a password does better. Read PART III: Using Secret Questions in @Jens Roland answer here in this wiki.

Session cookies

After the user logs in, the server sends the user a session cookie. The server can retrieve the username or id from the cookie, but nobody else can generate such a cookie (TODO explain mechanisms).

Cookies can be hijacked: they are only as secure as the rest of the client's machine and other communications. They can be read from disk, sniffed in network traffic, lifted by a cross-site scripting attack, phished from a poisoned DNS so the client sends their cookies to the wrong servers. Don't send persistent cookies. Cookies should expire at the end of the client session (browser close or leaving your domain).

If you want to autologin your users, you can set a persistent cookie, but it should be distinct from a full-session cookie. You can set an additional flag that the user has auto-logged in, and needs to log in for real for sensitive operations. This is popular with shopping sites that want to provide you with a seamless, personalized shopping experience but still protect your financial details. For example, when you return to visit Amazon, they show you a page that looks like you're logged in, but when you go to place an order (or change your shipping address, credit card etc.), they ask you to confirm your password.

Financial websites such as banks and credit cards, on the other hand, only have sensitive data and should not allow auto-login or a low-security mode.

List of external resources

How to specify an alternate location for the .m2 folder or settings.xml permanently?

Nobody suggested this, but you can use -Dmaven.repo.local command line argument to change where the repository is at. In addition, according to settings.xml documentation, you can set -Dmaven.home where it looks for the settings.xml file.

See: Settings.xml documentation

JavaScript/JQuery: $(window).resize how to fire AFTER the resize is completed?

Some of the previously mentioned solutions did not work for me, even though they are of more general usage. Alternatively I've found this one that did the job on window resize:

$(window).bind('resize', function(e){
    window.resizeEvt;
    $(window).resize(function(){
        clearTimeout(window.resizeEvt);
        window.resizeEvt = setTimeout(function(){
        //code to do after window is resized
        }, 250);
    });
});

TestNG ERROR Cannot find class in classpath

make sure your suite.xml should not have .java extension

ex :

<test name="Test C1">
    <classes>
        <class name="com.taxi.suiteC.TestCase_C1" ></class>  
    </classes>
</test>

What do the terms "CPU bound" and "I/O bound" mean?

An application is CPU-bound when the arithmetic/logical/floating-point (A/L/FP) performance during the execution is mostly near the theoretical peak-performance of the processor (data provided by the manufacturer and determined by the characteristics of the processor: number of cores, frequency, registers, ALUs, FPUs, etc.).

The peek performance is very difficult to be achieved in real-world applications, for not saying impossible. Most of the applications access memory in different parts of the execution and the processor is not doing A/L/FP operations during several cycles. This is called Von Neumann Limitation due to the distance that exists between the memory and the processor.

If you want to be near the CPU peak-performance a strategy could be to try to reuse most of the data in the cache memory in order to avoid requiring data from the main memory. An algorithm that exploits this feature is the matrix-matrix multiplication (if both matrices can be stored in the cache memory). This happens because if the matrices are size n x n then you need to do about 2 n^3 operations using only 2 n^2 FP numbers of data. On the other hand matrix addition, for example, is a less CPU-bound or a more memory-bound application than the matrix multiplication since it requires only n^2 FLOPs with the same data.

In the following figure the FLOPs obtained with a naive algorithms for the matrix addition and the matrix multiplication in an Intel i5-9300H, is shown:

FLOPs comparison between Matrix Addition and Matrix Multiplication

Note that as expected the performance of the matrix multiplication in bigger than the matrix addition. These results can be reproduced by running test/gemm and test/matadd available in this repository.

I suggest also to see the video given by J. Dongarra about this effect.

What static analysis tools are available for C#?

Code violation detection Tools:

  • Fxcop, excellent tool by Microsoft. Check compliance with .net framework guidelines.

    Edit October 2010: No longer available as a standalone download. It is now included in the Windows SDK and after installation can be found in Program Files\Microsoft SDKs\Windows\ [v7.1] \Bin\FXCop\FxCopSetup.exe

    Edit February 2018: This functionality has now been integrated into Visual Studio 2012 and later as Code Analysis

  • Clocksharp, based on code source analysis (to C# 2.0)

  • Mono.Gendarme, similar to Fxcop but with an opensource licence (based on Mono.Cecil)

  • Smokey, similar to Fxcop and Gendarme, based on Mono.Cecil. No longer on development, the main developer works with Gendarme team now.

  • Coverity Prevent™ for C#, commercial product

  • PRQA QA·C#, commercial product

  • PVS-Studio, commercial product

  • CAT.NET, visual studio addin that helps identification of security flaws Edit November 2019: Link is dead.

  • CodeIt.Right

  • Spec#

  • Pex

  • SonarQube, FOSS & Commercial options to support writing cleaner and safer code.

Quality Metric Tools:

  • NDepend, great visual tool. Useful for code metrics, rules, diff, coupling and dependency studies.
  • Nitriq, free, can easily write your own metrics/constraints, nice visualizations. Edit February 2018: download links now dead. Edit June 17, 2019: Links not dead.
  • RSM Squared, based on code source analysis
  • C# Metrics, using a full parse of C#
  • SourceMonitor, an old tool that occasionally gets updates
  • Code Metrics, a Reflector add-in
  • Vil, old tool that doesn't support .NET 2.0. Edit January 2018: Link now dead

Checking Style Tools:

  • StyleCop, Microsoft tool ( run from inside of Visual Studio or integrated into an MSBuild project). Also available as an extension for Visual Studio 2015 and C#6.0
  • Agent Smith, code style validation plugin for ReSharper

Duplication Detection:

  • Simian, based on source code. Works with plenty languages.
  • CloneDR, detects parameterized clones only on language boundaries (also handles many languages other than C#)
  • Clone Detective a Visual Studio plugin. (It uses ConQAT internally)
  • Atomiq, based on source code, plenty of languages, cool "wheel" visualization

General Refactoring tools

  • ReSharper - Majorly cool C# code analysis and refactoring features

CSS3 Continuous Rotate Animation (Just like a loading sundial)

You also might notice a little lag because 0deg and 360deg are the same spot, so it is going from spot 1 in a circle back to spot 1. It is really insignificant, but to fix it, all you have to do is change 360deg to 359deg

my jsfiddle illustrates your animation:

#myImg {
    -webkit-animation: rotation 2s infinite linear;
}

@-webkit-keyframes rotation {
    from {-webkit-transform: rotate(0deg);}
    to   {-webkit-transform: rotate(359deg);}
}

Also what might be more resemblant of the apple loading icon would be an animation that transitions the opacity/color of the stripes of gray instead of rotating the icon.

How do you count the elements of an array in java

Java doesn't have the concept of a "count" of the used elements in an array.

To get this, Java uses an ArrayList. The List is implemented on top of an array which gets resized whenever the JVM decides it's not big enough (or sometimes when it is too big).

To get the count, you use mylist.size() to ensure a capacity (the underlying array backing) you use mylist.ensureCapacity(20). To get rid of the extra capacity, you use mylist.trimToSize().

PHPExcel - set cell type before writing a value in it

I wanted the Number same as I get from database for example.

1) 00100.220000

2) 00123

3) 0000.0000100

So I modified the code as below

$objPHPExcel->getActiveSheet()
    ->setCellValue('A3', '00100.220000');
$objPHPExcel->getActiveSheet()
    ->getStyle('A3')
    ->getNumberFormat()
    ->setFormatCode('00000.000000');


$objPHPExcel->getActiveSheet()
    ->setCellValue('A4', '00123');
$objPHPExcel->getActiveSheet()
  ->getStyle('A4')
 ->getNumberFormat()
->setFormatCode('00000');


$objPHPExcel->getActiveSheet()
    ->setCellValue('A5', '0000.0000100');
$objPHPExcel->getActiveSheet()
  ->getStyle('A5')
 ->getNumberFormat()
->setFormatCode('0000.0000000');

How do I import a specific version of a package using go get?

The approach I've found workable is git's submodule system. Using that you can submodule in a given version of the code and upgrading/downgrading is explicit and recorded - never haphazard.

The folder structure I've taken with this is:

+ myproject
++ src
+++ myproject
+++ github.com
++++ submoduled_project of some kind.

Remove specific rows from a data frame

 X <- data.frame(Variable1=c(11,14,12,15),Variable2=c(2,3,1,4))
> X
  Variable1 Variable2
1        11         2
2        14         3
3        12         1
4        15         4
> X[X$Variable1!=11 & X$Variable1!=12, ]
  Variable1 Variable2
2        14         3
4        15         4
> X[ ! X$Variable1 %in% c(11,12), ]
  Variable1 Variable2
2        14         3
4        15         4

You can functionalize this however you like.

Disable pasting text into HTML form

Just got this, we can achieve it using onpaste:"return false", thanks to: http://sumtips.com/2011/11/prevent-copy-cut-paste-text-field.html

We have various other options available as listed below.

<input type="text" onselectstart="return false" onpaste="return false;" onCopy="return false" onCut="return false" onDrag="return false" onDrop="return false" autocomplete=off/><br>

How to send HTML-formatted email?

This works for me

msg.BodyFormat = MailFormat.Html;

and then you can use html in your body

msg.Body = "<em>It's great to use HTML in mail!!</em>"

What and where are the stack and heap?

The stack is the memory set aside as scratch space for a thread of execution. When a function is called, a block is reserved on the top of the stack for local variables and some bookkeeping data. When that function returns, the block becomes unused and can be used the next time a function is called. The stack is always reserved in a LIFO (last in first out) order; the most recently reserved block is always the next block to be freed. This makes it really simple to keep track of the stack; freeing a block from the stack is nothing more than adjusting one pointer.

The heap is memory set aside for dynamic allocation. Unlike the stack, there's no enforced pattern to the allocation and deallocation of blocks from the heap; you can allocate a block at any time and free it at any time. This makes it much more complex to keep track of which parts of the heap are allocated or free at any given time; there are many custom heap allocators available to tune heap performance for different usage patterns.

Each thread gets a stack, while there's typically only one heap for the application (although it isn't uncommon to have multiple heaps for different types of allocation).

To answer your questions directly:

To what extent are they controlled by the OS or language runtime?

The OS allocates the stack for each system-level thread when the thread is created. Typically the OS is called by the language runtime to allocate the heap for the application.

What is their scope?

The stack is attached to a thread, so when the thread exits the stack is reclaimed. The heap is typically allocated at application startup by the runtime, and is reclaimed when the application (technically process) exits.

What determines the size of each of them?

The size of the stack is set when a thread is created. The size of the heap is set on application startup, but can grow as space is needed (the allocator requests more memory from the operating system).

What makes one faster?

The stack is faster because the access pattern makes it trivial to allocate and deallocate memory from it (a pointer/integer is simply incremented or decremented), while the heap has much more complex bookkeeping involved in an allocation or deallocation. Also, each byte in the stack tends to be reused very frequently which means it tends to be mapped to the processor's cache, making it very fast. Another performance hit for the heap is that the heap, being mostly a global resource, typically has to be multi-threading safe, i.e. each allocation and deallocation needs to be - typically - synchronized with "all" other heap accesses in the program.

A clear demonstration:
Image source: vikashazrati.wordpress.com

How to make a dropdown readonly using jquery?

Here is a slight variation on the other answers that suggest using disabled. Since the "disabled" attribute can actually have any value and still disable, you can set it to readonly, like disabled="readonly". This will disable the control as usual, and will also allow you to easily style it differently than regular disabled controls, with CSS like:

select[disabled=readonly] {
    .... styles you like for read-only
}

If you want data to be included submit, use hidden fields or enable before submit, as detailed in the other answers.

Set LIMIT with doctrine 2?

Your setMaxResults($limit) needs to be set on the object.

e.g.

$query_ids = $this->getEntityManager()
  ->createQuery(
    "SELECT e_.id
    FROM MuzichCoreBundle:Element e_
    WHERE [...]
    GROUP BY e_.id")
;
$query_ids->setMaxResults($limit);

Not unique table/alias

Your query contains columns which could be present with the same name in more than one table you are referencing, hence the not unique error. It's best if you make the references explicit and/or use table aliases when joining.

Try

    SELECT pa.ProjectID, p.Project_Title, a.Account_ID, a.Username, a.Access_Type, c.First_Name, c.Last_Name
      FROM Project_Assigned pa
INNER JOIN Account a
        ON pa.AccountID = a.Account_ID
INNER JOIN Project p
        ON pa.ProjectID = p.Project_ID
INNER JOIN Clients c
        ON a.Account_ID = c.Account_ID
     WHERE a.Access_Type = 'Client';

What is the convention in JSON for empty vs. null?

There is the question whether we want to differentiate between cases:

  1. "phone" : "" = the value is empty

  2. "phone" : null = the value for "phone" was not set yet

If we want differentiate I would use null for this. Otherwise we would need to add a new field like "isAssigned" or so. This is an old Database issue.

Invariant Violation: Objects are not valid as a React child

My error was because of writing it this way:

props.allinfo.map((stuff, i)=>{
  return (<p key={i}> I am {stuff} </p>)
})



instead of:

props.allinfo.map((stuff, i)=>{
  return (<p key={i}> I am {stuff.name} </p>)
})

It meant I was trying to render object instead of the value within it.

edit: this is for react not native.

Where does Chrome store cookies?

On Windows the path is:

C:\Users\<current_user>\AppData\Local\Google\Chrome\User Data\<Profile 1>\Cookies(Type:File)

Chrome doesn't store each cookies in separate text file. It stores all of the cookies together in a single file in the profile folder. That file is not readable.

How do I center an SVG in a div?

make sure your css reads:

margin: 0 auto;

Even though you're saying you have the left and right set to auto, you may be placing an error. Of course we wouldn't know though because you did not show us any code.

Parsing JSON from URL

I use java 1.8 with com.fasterxml.jackson.databind.ObjectMapper

ObjectMapper mapper = new ObjectMapper();
Integer      value = mapper.readValue(new URL("your url here"), Integer.class);

Integer.class can be also a complex type. Just for example used.

Detect click outside element

There are already many answers to this question, and most of them are based on the similar custom directive idea. The problem with this approach is that one have to pass a method function to the directive, and cannot directly write code as in other events.

I created a new package vue-on-clickout that is different. Check it out at:

It allows one to write v-on:clickout just like any other events. For example, you can write

<div v-on:clickout="myField=value" v-on:click="myField=otherValue">...</div>

and it works.

Update

vue-on-clickout now supports Vue 3!

Update 2

vue-on-clickout is now replaced by a new package Clickout-Event which works for any front-end framework (or vanilla)!

How to retrieve a user environment variable in CMake (Windows)

You can also invoke itself to do this in a cross-platform way:

cmake -E env EnvironmentVariableName="Hello World" cmake ..

env [--unset=NAME]... [NAME=VALUE]... COMMAND [ARG]...

Run command in a modified environment.


Just be aware that this may only work the first time. If CMake re-configures with one of the consecutive builds (you just call e.g. make, one CMakeLists.txt was changed and CMake runs through the generation process again), the user defined environment variable may not be there anymore (in comparison to system wide environment variables).

So I transfer those user defined environment variables in my projects into a CMake cached variable:

cmake_minimum_required(VERSION 2.6)

project(PrintEnv NONE)

if (NOT "$ENV{EnvironmentVariableName}" STREQUAL "")
    set(EnvironmentVariableName "$ENV{EnvironmentVariableName}" CACHE INTERNAL "Copied from environment variable")
endif()

message("EnvironmentVariableName = ${EnvironmentVariableName}")

Reference

Check if a string contains an element from a list (of strings)

Based on your patterns one improvement would be to change to using StartsWith instead of Contains. StartsWith need only iterate through each string until it finds the first mismatch instead of having to restart the search at every character position when it finds one.

Also, based on your patterns, it looks like you may be able to extract the first part of the path for myString, then reverse the comparison -- looking for the starting path of myString in the list of strings rather than the other way around.

string[] pathComponents = myString.Split( Path.DirectorySeparatorChar );
string startPath = pathComponents[0] + Path.DirectorySeparatorChar;

return listOfStrings.Contains( startPath );

EDIT: This would be even faster using the HashSet idea @Marc Gravell mentions since you could change Contains to ContainsKey and the lookup would be O(1) instead of O(N). You would have to make sure that the paths match exactly. Note that this is not a general solution as is @Marc Gravell's but is tailored to your examples.

Sorry for the C# example. I haven't had enough coffee to translate to VB.

Create controller for partial view in ASP.NET MVC

If it were me, I would simply create a new Controller with a Single Action and then use RenderAction in place of Partial:

// Assuming the controller is named NewController
@{Html.RenderAction("ActionName", 
                     "New", 
                      new { routeValueOne = "SomeValue" });
}

How can I enable "URL Rewrite" Module in IIS 8.5 in Server 2012?

First, install the URL Rewrite from a download or from the Web Platform Installer. Second, restart IIS. And, finally, close IIS and open again. The last step worked for me.

C# IPAddress from string

You've probably miss-typed something above that bit of code or created your own class called IPAddress. If you're using the .net one, that function should be available.

Have you tried using System.Net.IPAddress just in case?

System.Net.IPAddress ipaddress = System.Net.IPAddress.Parse("127.0.0.1");  //127.0.0.1 as an example

The docs on Microsoft's site have a complete example which works fine on my machine.

PHP Unset Session Variable

I am including this answer in case someone comes to this page for the same reason I did. I just wasted an embarrassing amount of time trying to track the problem down. I was calling:

unset($_SESSION['myVar']);

from a logout script. Then navigating to a page that required login, and the server still thought I was logged in. The problem was that the logout script was not calling:

session_start();

Unsetting a session var DOES NOT WORK unless you start the session first.

How to send redirect to JSP page in Servlet

Please use the below code and let me know

try{

            Class.forName("com.mysql.jdbc.Driver").newInstance();
            con = DriverManager.getConnection(c, "root", "MyNewPass");
            System.out.println("connection done");


            PreparedStatement ps=con.prepareStatement(q);
            System.out.println(q);
            rs=ps.executeQuery();
            System.out.println("done2");
            while (rs.next()) {
               System.out.println(rs.getString(1));
               System.out.println(rs.getString(2));

            }

         response.sendRedirect("myfolder/welcome.jsp"); // wherever you wanna redirect this page.

        }
            catch (Exception e) {
                // TODO: handle exception
                System.out.println("Failed");
            }

myfolder/welcome.jsp is the relative path of your jsp page. So, change it as per your jsp page path.

Android EditText Hint

To complete Sunit's answer, you can use a selector, not to the text string but to the textColorHint. You must add this attribute on your editText:

android:textColorHint="@color/text_hint_selector"

And your text_hint_selector should be:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_focused="true" android:color="@android:color/transparent" />
    <item android:color="@color/hint_color" />
</selector>

Android ListView Text Color

Ok, here are some things that you should be clear about:

  1. The background color you are setting in your xml file is of the activity and not of the ListItems you are trying to define.
  2. Every list item has its own layout file which should be passed or inflated in case you are using complex layout for list item.

I'll try to explain this with a code sample:

****Lets start with ListItems layout** : save it in your res/layout folder of you Android project with say **list_black_text.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Definig a container for you List Item-->
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:gravity="center_vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <!-- Defining where should text be placed. You set you text color here-->
    <TextView
        android:id="@+id/list_content"
        android:textColor="#000000"
        android:gravity="center"
        android:text="sample"
        android:layout_margin="4dip"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
    />
</LinearLayout>

Well, a simple layout with a TextView to be precise. You must have an id assigned to TextView in order to use it.

Now coming to you screen/activity/chief layout, as I said you are defining background to your screen with android:background attribute. I see you have defined a TextView there as well and I suspect you are trying to define content/list item there, which is not at all needed.

Here's your edited layout:

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

    <ListView 
        android:id="@android:id/list" android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>
        <!-- REMOVED TEXT VIEW, AND KEEPING BACKGROUND WHITE -->
</LinearLayout>

And lastly, most importantly, set your adapter.

setListAdapter(new ArrayAdapter<String>(
            this, R.layout.list_black_text, R.id.list_content, listItems));

Notice the layout resource which we are passing to adapter R.layout.list_black_text, and R.id.list_content which is TextView ID we declared. I have also changed ArrayAdapter to String type since it's generic.

I hope this explains everything. Mark my answer accepted if you agree.

Messy but a good quick fix way
You can also do this with a quick fix if you do not want to go ahead with complex layout defining etc.

While instantiating the adapter declare an inner class to do this, here is the code sample:

    ArrayAdapter<String> adapter=new ArrayAdapter<String>(
            this, android.R.layout.simple_list_item_1, listItems){

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View view =super.getView(position, convertView, parent);

            TextView textView=(TextView) view.findViewById(android.R.id.text1);

            /*YOUR CHOICE OF COLOR*/
            textView.setTextColor(Color.BLUE);

            return view;
        }
    };

    /*SET THE ADAPTER TO LISTVIEW*/
    setListAdapter(adapter);

What does SQL clause "GROUP BY 1" mean?

It means to group by the first column regardless of what it's called. You can do the same with ORDER BY.

Redirect to Action in another controller

This should work

return RedirectToAction("actionName", "controllerName", null);

How do I show a message in the foreach loop?

You are looking to see if a single value is in an array. Use in_array.

However note that case is important, as are any leading or trailing spaces. Use var_dump to find out the length of the strings too, and see if they fit.

PowerShell array initialization

The solution I found was to use the New-Object cmdlet to initialize an array of the proper size.

$array = new-object object[] 5 
for($i=0; $i -lt $array.Length;$i++)
{
    $array[$i] = $FALSE
}

Get Application Directory

Just use this in your code

 context.getApplicationInfo().dataDir

Mail not sending with PHPMailer over SSL using SMTP

$mail->IsSMTP();
$mail->Host = "smtp.gmail.com";
$mail->SMTPAuth = true;
$mail->SMTPSecure = "ssl";
$mail->Username = "[email protected]";
$mail->Password = "**********";
$mail->Port = "465";

That is a working configuration.

try to replace what you have

Java - Best way to print 2D array?

I would prefer generally foreach when I don't need making arithmetic operations with their indices.

for (int[] x : array)
{
   for (int y : x)
   {
        System.out.print(y + " ");
   }
   System.out.println();
}

Increment counter with loop

You can use varStatus in your c:forEach loop

In your first example you can get the counter to work properly as follows...

<c:forEach var="tableEntity" items='${requestScope.tables}'>
   <c:forEach var="rowEntity" items='${tableEntity.rows}' varStatus="count">            
        my count is ${count.count}
    </c:forEach>
</c:forEach>

java.lang.UnsupportedClassVersionError: Unsupported major.minor version 51.0 (unable to load class frontend.listener.StartupListener)

What is your output when you do java -version? This will tell you what version the running JVM is.

The Unsupported major.minor version 51.0 error could mean:

  • Your server is running a lower Java version then the one used to compile your Servlet and vice versa

Either way, uninstall all JVM runtimes including JDK and download latest and re-install. That should fix any Unsupported major.minor error as you will have the lastest JRE and JDK (Maybe even newer then the one used to compile the Servlet)

See: http://www.java.com/en/download/manual.jsp (7 Update 25 )

and here: http://www.oracle.com/technetwork/java/javase/downloads/index.html (Java Platform (JDK) 7u25)

for the latest version of the JRE and JDK respectively.

EDIT:

Most likely your code was written in Java7 however maybe it was done using Java7update4 and your system is running Java7update3. Thus they both are effectively the same major version but the minor versions differ. Only the larger minor version is backward compatible with the lower minor version.

Edit 2 : If you have more than one jdk installed on your pc. you should check that Apache Tomcat is using the same one (jre) you are compiling your programs with. If you installed a new jdk after installing apache it normally won't select the new version.

Simple jQuery, PHP and JSONP example?

To make the server respond with a valid JSONP array, wrap the JSON in brackets () and preprend the callback:

echo $_GET['callback']."([{'fullname' : 'Jeff Hansen'}])";

Using json_encode() will convert a native PHP array into JSON:

$array = array(
    'fullname' => 'Jeff Hansen',
    'address' => 'somewhere no.3'
);
echo $_GET['callback']."(".json_encode($array).")";

What is difference between 'git reset --hard HEAD~1' and 'git reset --soft HEAD~1'?

Git reset has 5 main modes: soft, mixed, merged, hard, keep. The difference between them is to change or not change head, stage (index), working directory.

Git reset --hard will change head, index and working directory.
Git reset --soft will change head only. No change to index, working directory.

So in other words if you want to undo your commit, --soft should be good enough. But after that you still have the changes from bad commit in your index and working directory. You can modify the files, fix them, add them to index and commit again.

With the --hard, you completely get a clean slate in your project. As if there hasn't been any change from the last commit. If you are sure this is what you want then move forward. But once you do this, you'll lose your last commit completely. (Note: there are still ways to recover the lost commit).

Location of the mongodb database on mac

Thanks @Mark, I keep forgetting this again and again. After installing MongoDB with Homebrew:

  • The databases are stored in the /usr/local/var/mongodb/ directory
  • The mongod.conf file is here: /usr/local/etc/mongod.conf
  • The mongo logs can be found at /usr/local/var/log/mongodb/
  • The mongo binaries are here: /usr/local/Cellar/mongodb/[version]/bin

Attempt to set a non-property-list object as an NSUserDefaults

https://developer.apple.com/reference/foundation/userdefaults

A default object must be a property list—that is, an instance of (or for collections, a combination of instances of): NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary.

If you want to store any other type of object, you should typically archive it to create an instance of NSData. For more details, see Preferences and Settings Programming Guide.

What does "export" do in shell programming?

it makes the assignment visible to subprocesses.

$ foo=bar
$ bash -c 'echo $foo'

$ export foo
$ bash -c 'echo $foo'
bar

I got error "The DELETE statement conflicted with the REFERENCE constraint"

The error means that you have data in other tables that references the data you are trying to delete.

You would need to either drop and recreate the constraints or delete the data that the Foreign Key references.

Suppose you have the following tables

dbo.Students
(
StudentId
StudentName
StudentTypeId
)


dbo.StudentTypes
(
StudentTypeId
StudentType
)

Suppose a Foreign Key constraint exists between the StudentTypeId column in StudentTypes and the StudentTypeId column in Students

If you try to delete all the data in StudentTypes an error will occur as the StudentTypeId column in Students reference the data in the StudentTypes table.

EDIT:

DELETE and TRUNCATE essentially do the same thing. The only difference is that TRUNCATE does not save the changes in to the Log file. Also you can't use a WHERE clause with TRUNCATE

AS to why you can run this in SSMS but not via your Application. I really can't see this happening. The FK constraint would still throw an error regardless of where the transaction originated from.

How to fix/convert space indentation in Sublime Text?

I also followed Josh Frankel's advice and created a Sublime Macro + added key binding. The difference is that this script ensures that spacing is first set to tabs and set to a tab size of 2. The macro won't work if that's not the starting point.

Here's a gist of the macro: https://gist.github.com/drivelous/aa8dc907de34efa3e462c65a96e05f09

In Mac, to use the macro + key binding:

  1. Create a file called spaces2to4.sublime-macro and copy/paste the code from the gist. For me this is located at:

/Library/Application\ Support/Sublime\ Text\ 3/Packages/User/spaces2to4.sublime-macro

  1. Select Sublime Text > Preferences > Key Bindings
  2. Add this command to the User specified sublime-keymap (it's in an array -- it may be empty):
{
    "keys": ["super+shift+o"],
    "command": "run_macro_file",
    "args": {
        "file":"Packages/User/spaces2to4.sublime-macro"
    }
}

Now ? + shift + o now automatically converts each file from 2 space indentation to 4 (but will keep indenting if you run it further)

How to fix homebrew permissions?

Command from top-voted answer not work for me.

It got output:

chown: /usr/{my_username}dmin: illegal user name

This command works fine (group for /usr/local was admin already):

sudo chown -R $USER /usr/local

Cannot read property 'getContext' of null, using canvas

I guess the problem is your js runs before the html is loaded.

If you are using jquery, you can use the document ready function to wrap your code:

$(function() {
    var Grid = function(width, height) {
        // codes...
    }
});

Or simply put your js after the <canvas>.

How to detect when WIFI Connection has been established in Android?

The best that worked for me:

AndroidManifest

<receiver android:name="com.AEDesign.communication.WifiReceiver" >
   <intent-filter android:priority="100">
      <action android:name="android.net.wifi.STATE_CHANGE" />
   </intent-filter>
</receiver>

BroadcastReceiver class

public class WifiReceiver extends BroadcastReceiver {

   @Override
   public void onReceive(Context context, Intent intent) {

      NetworkInfo info = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
      if(info != null && info.isConnected()) {
        // Do your work. 

        // e.g. To check the Network Name or other info:
        WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);
        WifiInfo wifiInfo = wifiManager.getConnectionInfo();
        String ssid = wifiInfo.getSSID();
      }
   }
}

Permissions

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

What is w3wp.exe?

An Internet Information Services (IIS) worker process is a windows process (w3wp.exe) which runs Web applications, and is responsible for handling requests sent to a Web Server for a specific application pool.

It is the worker process for IIS. Each application pool creates at least one instance of w3wp.exe and that is what actually processes requests in your application. It is not dangerous to attach to this, that is just a standard windows message.

Is it ok to scrape data from Google results?

Google will eventually block your IP when you exceed a certain amount of requests.

What is Node.js' Connect, Express and "middleware"?

middleware as the name suggests actually middleware is sit between middle.. middle of what? middle of request and response..how request,response,express server sit in express app in this picture you can see requests are coming from client then the express server server serves those requests.. then lets dig deeper.. actually we can divide this whole express server's whole task in to small seperate tasks like in this way. how middleware sit between request and response small chunk of server parts doing some particular task and passed request to next one.. finally doing all the tasks response has been made.. all middle ware can access request object,response object and next function of request response cycle..

this is good example for explaining middleware in express youtube video for middleware

Heroku + node.js error (Web process failed to bind to $PORT within 60 seconds of launch)

Even if I'm too late but this might help someone who will get stuck too in the coming days. I faced the same issue but my problem was running many commands with npm start. I was running create tables and insert data before start the app and make 10 sec exceeds before running. So I removed those commands and problem solved.

Thanks

How do I get a file's directory using the File object?

File API File.getParent or File.getParentFile should return you Directory of file.

Your code should be like :

    File file = new File("c:\\temp\\java\\testfile");
    if(!file.exists()){
        file = file.getParentFile();
    }

You can additionally check your parent file is directory using File.isDirectory API

if(file.isDirectory()){
    System.out.println("file is directory ");
}

How do I remove the last comma from a string using PHP?

Solutions to apply during a loop:

//1 - Using conditional:

$source = array (1,2,3);
$total = count($source);
    
$str = null;
    
for($i=0; $i <= $total; $i++){ 
        
    if($i < $total) {
        $str .= $i.',';
    }
    else {
        $str .= $i;
    }
}
    
echo $str; //0,1,2,3

//2 - Using rtrim:

$source = array (1,2,3);
$total = count($source);

$str = null;

for($i=0; $i <= $total; $i++){ 
    
        $str .= $i.',';
}

$str = substr($str,0,strlen($str)-1);
echo $str; //0,1,2,3

Can't connect Nexus 4 to adb: unauthorized

Simply re-plugging did the trick for me.... The permissions-dialog didn't show up the first time I plugged in the device, the second time it did and everything is fine now.

Submit form using <a> tag

you can do it like this with raw javascript

<html>
    <body>
        <form id="my_form" method="post" action="mailto://[email protected]">
            <a href="javascript:{}" onclick="document.getElementById('my_form').submit();">submit</a>
        </form>
    </body>
</html>

For those asking why I have a href element in my anchor tag, its because it's a compulsory part of an anchor tag, it may well work without but it's not to spec. So if you want to guarantee rendering etc you must give the engine a fully formed tag. So the above achieves this. You will see href="#" used sometimes but this is not always wanted as the browser will change the page position.

How to get exit code when using Python subprocess communicate method?

You should first make sure that the process has completed running and the return code has been read out using the .wait method. This will return the code. If you want access to it later, it's stored as .returncode in the Popen object.

How can I quickly and easily convert spreadsheet data to JSON?

Assuming you really mean easiest and are not necessarily looking for a way to do this programmatically, you can do this:

  1. Add, if not already there, a row of "column Musicians" to the spreadsheet. That is, if you have data in columns such as:

    Rory Gallagher      Guitar
    Gerry McAvoy        Bass
    Rod de'Ath          Drums
    Lou Martin          Keyboards
    Donkey Kong Sioux   Self-Appointed Semi-official Stomper
    

    Note: you might want to add "Musician" and "Instrument" in row 0 (you might have to insert a row there)

  2. Save the file as a CSV file.

  3. Copy the contents of the CSV file to the clipboard

  4. Go to http://www.convertcsv.com/csv-to-json.htm

  5. Verify that the "First row is column names" checkbox is checked

  6. Paste the CSV data into the content area

  7. Mash the "Convert CSV to JSON" button

    With the data shown above, you will now have:

    [
      {
        "MUSICIAN":"Rory Gallagher",
        "INSTRUMENT":"Guitar"
      },
      {
        "MUSICIAN":"Gerry McAvoy",
        "INSTRUMENT":"Bass"
      },
      {
        "MUSICIAN":"Rod D'Ath",
        "INSTRUMENT":"Drums"
      },
      {
        "MUSICIAN":"Lou Martin",
        "INSTRUMENT":"Keyboards"
      }
      {
        "MUSICIAN":"Donkey Kong Sioux",
        "INSTRUMENT":"Self-Appointed Semi-Official Stomper"
      }
    ]
    

    With this simple/minimalistic data, it's probably not required, but with large sets of data, it can save you time and headache in the proverbial long run by checking this data for aberrations and abnormalcy.

  8. Go here: http://jsonlint.com/

  9. Paste the JSON into the content area

  10. Pres the "Validate" button.

If the JSON is good, you will see a "Valid JSON" remark in the Results section below; if not, it will tell you where the problem[s] lie so that you can fix it/them.

Python: list of lists

First, I strongly recommend that you rename your variable list to something else. list is the name of the built-in list constructor, and you're hiding its normal function. I will rename list to a in the following.

Python names are references that are bound to objects. That means that unless you create more than one list, whenever you use a it's referring to the same actual list object as last time. So when you call

listoflists.append((a, a[0]))

you can later change a and it changes what the first element of that tuple points to. This does not happen with a[0] because the object (which is an integer) pointed to by a[0] doesn't change (although a[0] points to different objects over the run of your code).

You can create a copy of the whole list a using the list constructor:

listoflists.append((list(a), a[0]))

Or, you can use the slice notation to make a copy:

listoflists.append((a[:], a[0]))

The type or namespace name 'Objects' does not exist in the namespace 'System.Data'

You need to add a reference to the .NET assembly System.Data.Entity.dll.

Fastest way to convert string to integer in PHP

$int = settype("100", "integer"); //convert the numeric string to int

What is the parameter "next" used for in Express?

Next is used to pass control to the next middleware function. If not the request will be left hanging or open.

How to allow only integers in a textbox?

Try This :

<input type="text"  onkeypress = "return isDigit(event,this.value);"/>

function isDigit(evt, txt) {
        var charCode = (evt.which) ? evt.which : event.keyCode

        var c = String.fromCharCode(charCode);

        if (txt.indexOf(c) > 0 && charCode == 46) {
            return false;
        }
        else if (charCode != 46 && charCode > 31 && (charCode < 48 || charCode > 57)) {
            return false;
        }

        return true;
    }

Call this function from input textbox on onkeypress event

Encrypt & Decrypt using PyCrypto AES 256

It's little late but i think this will be very helpful. No one mention about use scheme like PKCS#7 padding. You can use it instead the previous functions to pad(when do encryption) and unpad(when do decryption).i will provide the full Source Code below.

import base64
import hashlib
from Crypto import Random
from Crypto.Cipher import AES
import pkcs7
class Encryption:

    def __init__(self):
        pass

    def Encrypt(self, PlainText, SecurePassword):
        pw_encode = SecurePassword.encode('utf-8')
        text_encode = PlainText.encode('utf-8')

        key = hashlib.sha256(pw_encode).digest()
        iv = Random.new().read(AES.block_size)

        cipher = AES.new(key, AES.MODE_CBC, iv)
        pad_text = pkcs7.encode(text_encode)
        msg = iv + cipher.encrypt(pad_text)

        EncodeMsg = base64.b64encode(msg)
        return EncodeMsg

    def Decrypt(self, Encrypted, SecurePassword):
        decodbase64 = base64.b64decode(Encrypted.decode("utf-8"))
        pw_encode = SecurePassword.decode('utf-8')

        iv = decodbase64[:AES.block_size]
        key = hashlib.sha256(pw_encode).digest()

        cipher = AES.new(key, AES.MODE_CBC, iv)
        msg = cipher.decrypt(decodbase64[AES.block_size:])
        pad_text = pkcs7.decode(msg)

        decryptedString = pad_text.decode('utf-8')
        return decryptedString

import StringIO
import binascii


def decode(text, k=16):
    nl = len(text)
    val = int(binascii.hexlify(text[-1]), 16)
    if val > k:
        raise ValueError('Input is not padded or padding is corrupt')

    l = nl - val
    return text[:l]


def encode(text, k=16):
    l = len(text)
    output = StringIO.StringIO()
    val = k - (l % k)
    for _ in xrange(val):
        output.write('%02x' % val)
    return text + binascii.unhexlify(output.getvalue())

Converting RGB to grayscale/intensity

These values vary from person to person, especially for people who are colorblind.

Copying from one text file to another using Python

Just a slightly cleaned up way of doing this. This is no more or less performant than ATOzTOA's answer, but there's no reason to do two separate with statements.

with open(path_1, 'a') as file_1, open(path_2, 'r') as file_2:
    for line in file_2:
        if 'tests/file/myword' in line:
            file_1.write(line)

How can I send an email through the UNIX mailx command?

If you want to send more than two person or DL :

echo "Message Body" | mailx -s "Message Title" -r [email protected] [email protected],[email protected]

here:

  • -s = subject or mail title
  • -r = sender mail or DL

Define css class in django Forms

You can try this..

class SampleClass(forms.Form):
  name = forms.CharField(max_length=30)
  name.widget.attrs.update({'class': 'your-class'})
...

You can see more information in: Django Widgets

How can I detect if Flash is installed and if not, display a hidden div that informs the user?

I used Adobe's detection kit, originally suggested by justpassinby. Their system is nice because it detects the version number and compares it for you against your 'required version'

One bad thing is it does an alert showing the detected version of flash, which isn't very user friendly. All of a sudden a box pops up with some seemingly random numbers.

Some modifications you might want to consider:

  • remove the alert
  • change it so it returns an object (or array) --- first element is boolean true/false for "was the required version found on user's machine" --- second element is the actual version number found on user's machine

On Selenium WebDriver how to get Text from Span Tag

You need to locate the element and use getText() method to extract the text.

WebElement element = driver.findElement(By.id("customSelect_3"));
System.out.println(element.getText());

Clearing an input text field in Angular2

1. First Method

you have to assign null or empty string here

this.searchValue = null;
//or
this.searchValue = ' ';

Working Plunker

because no event is being fired from angular change detection. so you have to assign some value either null or string with space

2. Second Method

  • use of [(ngModel)] it should work with ngModel.

why ?

because as you did binding with value attribute which is only property binding not event binding. so angular doesn't run change detection because no event relevant to Angular is fired. If you bind to an event then Angular runs change detection and the binding works and value should be changes.

see working example of same with ngModel

Working Example with ngModel

Convert Unix timestamp to a date string

Slight correction to dabest1's answer above. Specify the timezone as UTC, not GMT:

$ date -d '1970-01-01 1416275583 sec GMT'
Tue Nov 18 00:53:03 GMT 2014
$ date -d '1970-01-01 1416275583 sec UTC'
Tue Nov 18 01:53:03 GMT 2014

The second one is correct. I think the reason is that in the UK, daylight saving was in force continually from 1968 to 1971.

The following sections have been defined but have not been rendered for the layout page "~/Views/Shared/_Layout.cshtml": "Scripts"

I'm not sure why the accepted answer was accepted if the suggested solution did not and does not solve the issue. There can actually be two related issues related to this topic.

Issue #1

The master page (e.g. _Layout.cshtml) has a section defined and it is required but the inheriting views did not implement it. For example,

The Layout Template

<body>
    @* Visible only to admin users *@
    <div id="option_box"> 
        @* this section is required due to the absence of the second parameter *@
        @RenderSection("OptionBox") 
    </div>
</body>

The Inheriting View

No need to show any code, just consider that there is no implementation of @section OptionBox {} on the view.

The Error for Issue #1

Section not defined: "OptionBox ".

Issue #2

The master page (e.g. _Layout.cshtml) has a section defined and it is required AND the inheriting view did implement it. However, the implementing view have additional script sections that are not defined on (any of) its master page(s).

The Layout Template

same as above

The Inheriting View

<div>
  <p>Looks like the Lakers can still make it to the playoffs</p>
</div>
@section OptionBox {
<a href"">Go and reserve playoff tickets now</a>
}
@section StatsBox {
<ul>
    <li>1. San Antonio</li>
    <li>8. L. A. Lakers</li>
</ul>
}

The Error for Issue #2

The following sections have been defined but have not been rendered for the layout page "~/Views/Shared/_Layout.cshtml": "StatsBox"

The OP's issue is similar to Issue #2 and the accepted answer is for Issue #1.

Ajax Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource

Place below line at the top of the file which you are calling through AJAX.

header("Access-Control-Allow-Origin: *");

symfony 2 No route found for "GET /"

Using symfony 2.3 with php 5.5 and using the built in server with

app/console server:run

which should output something like:

Server running on http://127.0.0.1:8000
Quit the server with CONTROL-C.

then go to http://127.0.0.1:8000/app_dev.php/app/example

this should give you the default, which you can also find the default route by viewing src/AppBundle/Controller/DefaultController.php

Override devise registrations controller

A better and more organized way of overriding Devise controllers and views using namespaces:

Create the following folders:

app/controllers/my_devise
app/views/my_devise

Put all controllers that you want to override into app/controllers/my_devise and add MyDevise namespace to controller class names. Registrations example:

# app/controllers/my_devise/registrations_controller.rb
class MyDevise::RegistrationsController < Devise::RegistrationsController

  ...

  def create
    # add custom create logic here
  end

  ...    

end 

Change your routes accordingly:

devise_for :users,
           :controllers  => {
             :registrations => 'my_devise/registrations',
             # ...
           }

Copy all required views into app/views/my_devise from Devise gem folder or use rails generate devise:views, delete the views you are not overriding and rename devise folder to my_devise.

This way you will have everything neatly organized in two folders.

How do I find what Java version Tomcat6 is using?

Or you could use the Probe application and just look at its System Info page. Much easier than writing code, and once you start using it you'll never go back to Tomcat Manager.

How do I make a checkbox required on an ASP.NET form?

If you want a true validator that does not rely on jquery and handles server side validation as well ( and you should. server side validation is the most important part) then here is a control

public class RequiredCheckBoxValidator : System.Web.UI.WebControls.BaseValidator
{
    private System.Web.UI.WebControls.CheckBox _ctrlToValidate = null;
    protected System.Web.UI.WebControls.CheckBox CheckBoxToValidate
    {
        get
        {
            if (_ctrlToValidate == null)
                _ctrlToValidate = FindControl(this.ControlToValidate) as System.Web.UI.WebControls.CheckBox;

            return _ctrlToValidate;
        }
    }

    protected override bool ControlPropertiesValid()
    {
        if (this.ControlToValidate.Length == 0)
            throw new System.Web.HttpException(string.Format("The ControlToValidate property of '{0}' is required.", this.ID));

        if (this.CheckBoxToValidate == null)
            throw new System.Web.HttpException(string.Format("This control can only validate CheckBox."));

        return true;
    }

    protected override bool EvaluateIsValid()
    {
        return CheckBoxToValidate.Checked;
    }

    protected override void OnPreRender(EventArgs e)
    {
        base.OnPreRender(e);

        if (this.Visible && this.Enabled)
        {
            System.Web.UI.ClientScriptManager cs = this.Page.ClientScript;
            if (this.DetermineRenderUplevel() && this.EnableClientScript)
            {
                cs.RegisterExpandoAttribute(this.ClientID, "evaluationfunction", "cb_verify", false);
            }
            if (!this.Page.ClientScript.IsClientScriptBlockRegistered(this.GetType().FullName))
            {
                cs.RegisterClientScriptBlock(this.GetType(), this.GetType().FullName, GetClientSideScript());
            } 
        }
    }

    private string GetClientSideScript()
    {
        return @"<script language=""javascript"">function cb_verify(sender) {var cntrl = document.getElementById(sender.controltovalidate);return cntrl.checked;}</script>";
    }
}

Checking if a textbox is empty in Javascript

function valid(id)
    {
        var textVal=document.getElementById(id).value;
        if (!textVal.match("Tryit") 
        {
            alert("Field says Tryit");
            return false;
        } 
        else 
        {
            return true;
        }
     }

Use this for expressing things

Seaborn plots not showing up

Plots created using seaborn need to be displayed like ordinary matplotlib plots. This can be done using the

plt.show()

function from matplotlib.

Originally I posted the solution to use the already imported matplotlib object from seaborn (sns.plt.show()) however this is considered to be a bad practice. Therefore, simply directly import the matplotlib.pyplot module and show your plots with

import matplotlib.pyplot as plt
plt.show()

If the IPython notebook is used the inline backend can be invoked to remove the necessity of calling show after each plot. The respective magic is

%matplotlib inline

Splitting a Java String by the pipe symbol using split("|")

Use this code:

public static void main(String[] args) {
    String test = "A|B|C||D";

    String[] result = test.split("\\|");

    for (String s : result) {
        System.out.println(">" + s + "<");
    }
}

ASP.NET file download from server

Making changes as below and redeploying on server content type as

Response.ContentType = "application/octet-stream";

This worked for me.

Response.Clear(); 
Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name); 
Response.AddHeader("Content-Length", file.Length.ToString()); 
Response.ContentType = "application/octet-stream"; 
Response.WriteFile(file.FullName); 
Response.End();

How to define a List bean in Spring?

I think you may be looking for org.springframework.beans.factory.config.ListFactoryBean.

You declare a ListFactoryBean instance, providing the list to be instantiated as a property withe a <list> element as its value, and give the bean an id attribute. Then, each time you use the declared id as a ref or similar in some other bean declaration, a new copy of the list is instantiated. You can also specify the List class to be used.

How to read file with space separated values in pandas

add delim_whitespace=True argument, it's faster than regex.

How to continue the code on the next line in VBA

In VBA (and VB.NET) the line terminator (carriage return) is used to signal the end of a statement. To break long statements into several lines, you need to

Use the line-continuation character, which is an underscore (_), at the point at which you want the line to break. The underscore must be immediately preceded by a space and immediately followed by a line terminator (carriage return).

(From How to: Break and Combine Statements in Code)

In other words: Whenever the interpreter encounters the sequence <space>_<line terminator>, it is ignored and parsing continues on the next line. Note, that even when ignored, the line continuation still acts as a token separator, so it cannot be used in the middle of a variable name, for example. You also cannot continue a comment by using a line-continuation character.

To break the statement in your question into several lines you could do the following:

U_matrix(i, j, n + 1) = _
     k * b_xyt(xi, yi, tn) / (4 * hx * hy) * U_matrix(i + 1, j + 1, n) + _
     (k * (a_xyt(xi, yi, tn) / hx ^ 2 + d_xyt(xi, yi, tn) / (2 * hx)))

(Leading whitespaces are ignored.)

Make a negative number positive

I needed the absolute value of a long , and looked deeply into Math.abs and found that if my argument is less than LONG.MIN_VAL which is -9223372036854775808l, then the abs function would not return an absolute value but only the minimum value. Inthis case if your code is using this abs value further then there might be an issue.

How to use orderby with 2 fields in linq?

MyList.OrderBy(x => x.StartDate).ThenByDescending(x => x.EndDate);

Note that you can use as well the Descending keyword in the OrderBy (in case you need). So another possible answer is:

MyList.OrderByDescending(x => x.StartDate).ThenByDescending(x => x.EndDate);

How do I get current scope dom-element in AngularJS controller?

In controller:

function innerItem($scope, $element){
    var jQueryInnerItem = $($element); 
}

How can I create my own comparator for a map?

Yes, the 3rd template parameter on map specifies the comparator, which is a binary predicate. Example:

struct ByLength : public std::binary_function<string, string, bool>
{
    bool operator()(const string& lhs, const string& rhs) const
    {
        return lhs.length() < rhs.length();
    }
};

int main()
{
    typedef map<string, string, ByLength> lenmap;
    lenmap mymap;

    mymap["one"] = "one";
    mymap["a"] = "a";
    mymap["fewbahr"] = "foobar";

    for( lenmap::const_iterator it = mymap.begin(), end = mymap.end(); it != end; ++it )
        cout << it->first << "\n";
}

Best C++ Code Formatter/Beautifier

AStyle can be customized in great detail for C++ and Java (and others too)

This is a source code formatting tool.


clang-format is a powerful command line tool bundled with the clang compiler which handles even the most obscure language constructs in a coherent way.

It can be integrated with Visual Studio, Emacs, Vim (and others) and can format just the selected lines (or with git/svn to format some diff).

It can be configured with a variety of options listed here.

When using config files (named .clang-format) styles can be per directory - the closest such file in parent directories shall be used for a particular file.

Styles can be inherited from a preset (say LLVM or Google) and can later override different options

It is used by Google and others and is production ready.


Also look at the project UniversalIndentGUI. You can experiment with several indenters using it: AStyle, Uncrustify, GreatCode, ... and select the best for you. Any of them can be run later from a command line.


Uncrustify has a lot of configurable options. You'll probably need Universal Indent GUI (in Konstantin's reply) as well to configure it.

What's the safest way to iterate through the keys of a Perl hash?

The place where each can cause you problems is that it's a true, non-scoped iterator. By way of example:

while ( my ($key,$val) = each %a_hash ) {
    print "$key => $val\n";
    last if $val; #exits loop when $val is true
}

# but "each" hasn't reset!!
while ( my ($key,$val) = each %a_hash ) {
    # continues where the last loop left off
    print "$key => $val\n";
}

If you need to be sure that each gets all the keys and values, you need to make sure you use keys or values first (as that resets the iterator). See the documentation for each.

Create a Path from String in Java7

You can just use the Paths class:

Path path = Paths.get(textPath);

... assuming you want to use the default file system, of course.

How can I get CMake to find my alternative Boost installation?

I also encountered the same problem, but trying the hints here didn't help, unfortunately.

The only thing that helped was to download the newest version from the Boost page, compile and install it as described in Installing Boost 1.50 on Ubuntu 12.10.

In my case I worked with Boost 1.53.

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

Quoted from monsur,

The Access-Control-Allow-Headers header does not allow wildcards. It must be an exact match: http://www.w3.org/TR/cors/#access-control-allow-headers-response-header.

So here is my php solution.

if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
  $headers=getallheaders();
  @$ACRH=$headers["Access-Control-Request-Headers"];
  header("Access-Control-Allow-Headers: $ACRH");
}

How to float 3 divs side by side using CSS?

Float all three divs to the left. Like here:

.first-div {
  width:370px;
  height:150px;
  float:left;
  background-color:pink;
}

.second-div {
  width:370px;
  height:150px;
  float:left;
  background-color:blue;
}

.third-div {
  width:370px;
  height:150px;
  float:left;
  background-color:purple;
}

right click context menu for datagridview

Use the CellMouseDown event on the DataGridView. From the event handler arguments you can determine which cell was clicked. Using the PointToClient() method on the DataGridView you can determine the relative position of the pointer to the DataGridView, so you can pop up the menu in the correct location.

(The DataGridViewCellMouseEvent parameter just gives you the X and Y relative to the cell you clicked, which isn't as easy to use to pop up the context menu.)

This is the code I used to get the mouse position, then adjust for the position of the DataGridView:

var relativeMousePosition = DataGridView1.PointToClient(Cursor.Position);
this.ContextMenuStrip1.Show(DataGridView1, relativeMousePosition);

The entire event handler looks like this:

private void DataGridView1_CellMouseDown(object sender, DataGridViewCellMouseEventArgs e)
{
    // Ignore if a column or row header is clicked
    if (e.RowIndex != -1 && e.ColumnIndex != -1)
    {
        if (e.Button == MouseButtons.Right)
        {
            DataGridViewCell clickedCell = (sender as DataGridView).Rows[e.RowIndex].Cells[e.ColumnIndex];

            // Here you can do whatever you want with the cell
            this.DataGridView1.CurrentCell = clickedCell;  // Select the clicked cell, for instance

            // Get mouse position relative to the vehicles grid
            var relativeMousePosition = DataGridView1.PointToClient(Cursor.Position);

            // Show the context menu
            this.ContextMenuStrip1.Show(DataGridView1, relativeMousePosition);
        }
    }
}

Selecting an element in iFrame jQuery

here is simple JQuery to do this to make div draggable with in only container :

$("#containerdiv div").draggable( {containment: "#containerdiv ", scroll: false} );

How to check if current thread is not main thread

Allow me to preface this with: I acknowledged this post has the 'Android' tag, however, my search had nothing to do with 'Android' and this was my top result. To that end, for the non-Android SO Java users landing here, don't forget about:

public static void main(String[] args{
    Thread.currentThread().setName("SomeNameIChoose");
    /*...the rest of main...*/
}

After setting this, elsewhere in your code, you can easily check if you're about to execute on the main thread with:

if(Thread.currentThread().getName().equals("SomeNameIChoose"))
{
    //do something on main thread
}

A bit embarrassed I had searched before remembering this, but hopefully it will help someone else!

Android: how to make keyboard enter button say "Search" and handle its click?

This answer is for TextInputEditText :

In the layout XML file set your input method options to your required type. for example done.

<com.google.android.material.textfield.TextInputLayout
        android:id="@+id/textInputLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <com.google.android.material.textfield.TextInputEditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:imeOptions="actionGo"/>

</com.google.android.material.textfield.TextInputLayout>

Similarly, you can also set imeOptions to actionSubmit, actionSearch, etc

In the java add the editor action listener.

TextInputLayout textInputLayout = findViewById(R.id.textInputLayout);

textInputLayout.getEditText().setOnEditorActionListener(new 

    TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            if (actionId == EditorInfo.IME_ACTION_GO) {
                performYourAction();
                return true;
            }
            return false;
        }
    });

If you're using kotlin :

textInputLayout.editText.setOnEditorActionListener { _, actionId, _ ->
    if (actionId == EditorInfo.IME_ACTION_GO) {
        performYourAction()
    }
    true
}

Access blocked by CORS policy: Response to preflight request doesn't pass access control check

You have to set the http header at the http response of your resource. So it needs to be set serverside, you can remove the "HTTP_OPTIONS"-header from your angular HTTP-Post request.

OpenCV Python rotate image by X degrees around specific point

Quick tweak to @alex-rodrigues answer... deals with shape including the number of channels.

import cv2
import numpy as np

def rotateImage(image, angle):
    center=tuple(np.array(image.shape[0:2])/2)
    rot_mat = cv2.getRotationMatrix2D(center,angle,1.0)
    return cv2.warpAffine(image, rot_mat, image.shape[0:2],flags=cv2.INTER_LINEAR)

Open an html page in default browser with VBA?

You can use the Windows API function ShellExecute to do so:

Option Explicit

Private Declare Function ShellExecute _
  Lib "shell32.dll" Alias "ShellExecuteA" ( _
  ByVal hWnd As Long, _
  ByVal Operation As String, _
  ByVal Filename As String, _
  Optional ByVal Parameters As String, _
  Optional ByVal Directory As String, _
  Optional ByVal WindowStyle As Long = vbMinimizedFocus _
  ) As Long

Public Sub OpenUrl()

    Dim lSuccess As Long
    lSuccess = ShellExecute(0, "Open", "www.google.com")

End Sub

Just a short remark concerning security: If the URL comes from user input make sure to strictly validate that input as ShellExecute would execute any command with the user's permissions, also a format c: would be executed if the user is an administrator.

How to extract public key using OpenSSL?

If your looking how to copy an Amazon AWS .pem keypair into a different region do the following:

openssl rsa -in .ssh/amazon-aws.pem -pubout > .ssh/amazon-aws.pub

Then

aws ec2 import-key-pair --key-name amazon-aws --public-key-material '$(cat .ssh/amazon-aws.pub)' --region us-west-2

Decode Hex String in Python 3

Something like:

>>> bytes.fromhex('4a4b4c').decode('utf-8')
'JKL'

Just put the actual encoding you are using.

Find a class somewhere inside dozens of JAR files?

grep -l "classname" *.jar

gives you the name of the jar

find . -name "*.jar" -exec jar -t -f {} \; | grep  "classname"

gives you the package of the class

Relative frequencies / proportions with dplyr

Here is a base R answer using aggregate and ave :

df1 <- with(mtcars, aggregate(list(n = mpg), list(am = am, gear = gear), length))
df1$prop <- with(df1, n/ave(n, am, FUN = sum))
#Also with prop.table
#df1$prop <- with(df1, ave(n, am, FUN = prop.table))
df1

#  am gear  n      prop
#1  0    3 15 0.7894737
#2  0    4  4 0.2105263
#3  1    4  8 0.6153846
#4  1    5  5 0.3846154 

We can also use prop.table but the output displays differently.

prop.table(table(mtcars$am, mtcars$gear), 1)
   
#            3         4         5
#  0 0.7894737 0.2105263 0.0000000
#  1 0.0000000 0.6153846 0.3846154

How do I define the name of image built with docker-compose

Depending on your use case, you can use an image which has already been created and specify it's name in docker-compose.

We have a production use case where our CI server builds a named Docker image. (docker build -t <specific_image_name> .). Once the named image is specified, our docker-compose always builds off of the specific image. This allows a couple of different possibilities:

1- You can ensure that where ever you run your docker-compose from, you will always be using the latest version of that specific image.

2- You can specify multiple named images in your docker-compose file and let them be auto-wired through the previous build step.

So, if your image is already built, you can name the image with docker-compose. Remove build and specify image:

wildfly:
  image: my_custom_wildfly_image
  container_name: wildfly_server
  ports:
   - 9990:9990
   - 80:8080
  environment:
   - MYSQL_HOST=mysql_server
   - MONGO_HOST=mongo_server
   - ELASTIC_HOST=elasticsearch_server
  volumes:
   - /Volumes/CaseSensitive/development/wildfly/deployments/:/opt/jboss/wildfly/standalone/deployments/
  links:
   - mysql:mysql_server
   - mongo:mongo_server
   - elasticsearch:elasticsearch_server

How do I center a Bootstrap div with a 'spanX' class?

If anyone wants the true solution for centering BOTH images and text within a span using bootstrap row-fluid, here it is (how to implement this and explanation follows my example):

css

div.row-fluid [class*="span"] .center-in-span { 
   float: none; 
   margin: 0 auto; 
   text-align: center; 
   display: block; 
   width: auto; 
   height: auto;
}

html

<div class="row-fluid">
   <div class="span12">
      <img class="center-in-span" alt="MyExample" src="/path/to/example.jpg"/>
   </div>
</div>

<div class="row-fluid">
   <div class="span12">
      <p class="center-in-span">this is text</p>
   </div>
</div>

USAGE: To use this css to center an image within a span, simply apply the .center-in-span class to the img element, as shown above.

To use this css to center text within a span, simply apply the .center-in-span class to the p element, as shown above.

EXPLANATION: This css works because we are overriding specific bootstrap styling. The notable differences from the other answers that were posted are that the width and height are set to auto, so you don't have to used a fixed with (good for a dynamic webpage). also, the combination of setting the margin to auto, text-align:center and display:block, takes care of both images and paragraphs.

Let me know if this is thorough enough for easy implementation.

How to check if a folder exists

There is no need to separately call the exists() method, as isDirectory() implicitly checks whether the directory exists or not.

Iterate over object attributes in python

For all the pythonian zealots out there I'm sure Johan Cleeze would approve of your dogmatism ;). I'm leaving this answer keep demeriting it It actually makes me more confidant. Leave a comment you chickens!

For python 3.6

class SomeClass:

    def attr_list1(self, should_print=False):

        for k in self.__dict__.keys():
            v = self.__dict__.__getitem__(k)
            if should_print:
                print(f"attr: {k}    value: {v}")

    def attr_list(self, should_print=False):

        b = [(k, v) for k, v in self.__dict__.items()]
        if should_print:
            [print(f"attr: {a[0]}    value: {a[1]}") for a in b]
        return b

How to place two divs next to each other?

My approach:

<div class="left">Left</div>
<div class="right">Right</div>

CSS:

.left {
    float: left;
    width: calc(100% - 200px);
    background: green;
}

.right {
    float: right;
    width: 200px;
    background: yellow;
}

Replace deprecated preg_replace /e with preg_replace_callback

You can use an anonymous function to pass the matches to your function:

$result = preg_replace_callback(
    "/\{([<>])([a-zA-Z0-9_]*)(\?{0,1})([a-zA-Z0-9_]*)\}(.*)\{\\1\/\\2\}/isU",
    function($m) { return CallFunction($m[1], $m[2], $m[3], $m[4], $m[5]); },
    $result
);

Apart from being faster, this will also properly handle double quotes in your string. Your current code using /e would convert a double quote " into \".

How do I do a case-insensitive string comparison?

Assuming ASCII strings:

string1 = 'Hello'
string2 = 'hello'

if string1.lower() == string2.lower():
    print("The strings are the same (case insensitive)")
else:
    print("The strings are NOT the same (case insensitive)")

how to set auto increment column with sql developer

If you want to make your PK auto increment, you need to set the ID column property for that primary key.

  1. Right click on the table and select "Edit".
  2. In "Edit" Table window, select "columns", and then select your PK column.
  3. Go to ID Column tab and select Column Sequence as Type. This will create a trigger and a sequence, and associate the sequence to primary key.

See the picture below for better understanding.

enter image description here

// My source is: http://techatplay.wordpress.com/2013/11/22/oracle-sql-developer-create-auto-incrementing-primary-key/

How to retrieve the dimensions of a view?

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

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

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

Getting error "The package appears to be corrupt" while installing apk file

After searching a lot I found a solution:

Go to Build-> Build Apk(s).

After creating apk you will see a dialog as below.

enter image description here

Click on locate and install it in your phone

Enjoy

Select records from NOW() -1 Day

You're almost there: it's NOW() - INTERVAL 1 DAY

How do you remove Subversion control for a folder?

On Windows 7 one can just open the project folder and do a search for ".svn" if hidden files are enabled and delete all found .svn folders.

Explanation of the UML arrows

Aggregations and compositions are a little bit confusing. However, think like compositions are a stronger version of aggregation. What does that mean? Let's take an example: (Aggregation) 1. Take a classroom and students: In this case, we try to analyze the relationship between them. A classroom has a relationship with students. That means classroom comprises of one or many students. Even if we remove the Classroom class, the Students class does not need to destroy, which means we can use Student class independently.

(Composition) 2. Take a look at pages and Book Class. In this case, pages is a book, which means collections of pages makes the book. If we remove the book class, the whole Page class will be destroyed. That means we cannot use the class of the page independently.

If you are still unclear about this topic, watch out this short wonderful video, which has explained the aggregation more clearly.

https://www.youtube.com/watch?v=d5ecYmyFZW0

Using Spring MVC Test to unit test multipart POST request

Since MockMvcRequestBuilders#fileUpload is deprecated, you'll want to use MockMvcRequestBuilders#multipart(String, Object...) which returns a MockMultipartHttpServletRequestBuilder. Then chain a bunch of file(MockMultipartFile) calls.

Here's a working example. Given a @Controller

@Controller
public class NewController {

    @RequestMapping(value = "/upload", method = RequestMethod.POST)
    @ResponseBody
    public String saveAuto(
            @RequestPart(value = "json") JsonPojo pojo,
            @RequestParam(value = "some-random") String random,
            @RequestParam(value = "data", required = false) List<MultipartFile> files) {
        System.out.println(random);
        System.out.println(pojo.getJson());
        for (MultipartFile file : files) {
            System.out.println(file.getOriginalFilename());
        }
        return "success";
    }

    static class JsonPojo {
        private String json;

        public String getJson() {
            return json;
        }

        public void setJson(String json) {
            this.json = json;
        }

    }
}

and a unit test

@WebAppConfiguration
@ContextConfiguration(classes = WebConfig.class)
@RunWith(SpringJUnit4ClassRunner.class)
public class Example {

    @Autowired
    private WebApplicationContext webApplicationContext;

    @Test
    public void test() throws Exception {

        MockMultipartFile firstFile = new MockMultipartFile("data", "filename.txt", "text/plain", "some xml".getBytes());
        MockMultipartFile secondFile = new MockMultipartFile("data", "other-file-name.data", "text/plain", "some other type".getBytes());
        MockMultipartFile jsonFile = new MockMultipartFile("json", "", "application/json", "{\"json\": \"someValue\"}".getBytes());

        MockMvc mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build();
        mockMvc.perform(MockMvcRequestBuilders.multipart("/upload")
                        .file(firstFile)
                        .file(secondFile)
                        .file(jsonFile)
                        .param("some-random", "4"))
                    .andExpect(status().is(200))
                    .andExpect(content().string("success"));
    }
}

And the @Configuration class

@Configuration
@ComponentScan({ "test.controllers" })
@EnableWebMvc
public class WebConfig extends WebMvcConfigurationSupport {
    @Bean
    public MultipartResolver multipartResolver() {
        CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver();
        return multipartResolver;
    }
}

The test should pass and give you output of

4 // from param
someValue // from json file
filename.txt // from first file
other-file-name.data // from second file

The thing to note is that you are sending the JSON just like any other multipart file, except with a different content type.

How to fix curl: (60) SSL certificate: Invalid certificate chain

Another cause of this can be duplicate keys in your KeyChain. I've seen this problem on two macs where there were duplicate "DigiCert High Assurance EV Root CA". One was in the login keychain, the other in the system one. Removing the certificate from the login keychain solved the problem.

This affected Safari browser as well as git on the command line.

Check if a file exists in jenkins pipeline

You need to use brackets when using the fileExists step in an if condition or assign the returned value to a variable

Using variable:

def exists = fileExists 'file'

if (exists) {
    echo 'Yes'
} else {
    echo 'No'
}

Using brackets:

if (fileExists('file')) {
    echo 'Yes'
} else {
    echo 'No'
}

unix diff side-to-side results?

Use the -y option:

diff -y file1 file2

DateDiff to output hours and minutes

I would make your final select as:

SELECT    EmplID
        , EmplName
        , InTime
        , [TimeOut]
        , [DateVisited]
        , CONVERT(varchar(3),DATEDIFF(minute,InTime, TimeOut)/60) + ':' +
          RIGHT('0' + CONVERT(varchar(2),DATEDIFF(minute,InTime,TimeOut)%60),2)
          as TotalHours
from times
Order By EmplID, DateVisited 

Any solution trying to use DATEDIFF(hour,... is bound to be complicated (if it's correct) because DATEDIFF counts transitions - DATEDIFF(hour,...09:59',...10:01') will return 1 because of the transition of the hour from 9 to 10. So I'm just using DATEDIFF on minutes.

The above can still be subtly wrong if seconds are involved (it can slightly overcount because its counting minute transitions) so if you need second or millisecond accuracy you need to adjust the DATEDIFF to use those units and then apply suitable division constants (as per the hours one above) to just return hours and minutes.

How to identify object types in java

You can compare class tokens to each other, so you could use value.getClass() == Integer.class. However, the simpler and more canonical way is to use instanceof :

    if (value instanceof Integer) {
        System.out.println("This is an Integer");
    } else if(value instanceof String) {
        System.out.println("This is a String");
    } else if(value instanceof Float) {
        System.out.println("This is a Float");
    }

Notes:

  • the only difference between the two is that comparing class tokens detects exact matches only, while instanceof C matches for subclasses of C too. However, in this case all the classes listed are final, so they have no subclasses. Thus instanceof is probably fine here.
  • as JB Nizet stated, such checks are not OO design. You may be able to solve this problem in a more OO way, e.g.

    System.out.println("This is a(n) " + value.getClass().getSimpleName());
    

package javax.servlet.http does not exist

If you are using Ant and trying to build then you need to :

  1. Specify tomcat location by <property name="tomcat-home" value="C:\xampp\tomcat" />

  2. Add tomcat libs to your already defined path for jars by

    <path id="libs"> <fileset includes="*.jar" dir="${WEB-INF}/lib" /> <fileset includes="*.jar" dir="${tomcat-home}/bin" /> <fileset includes="*.jar" dir="${tomcat-home}/lib" /> </path>

Python regex findall

you can replace your pattern with

regex = ur"\[P\]([\w\s]+)\[\/P\]"

Can you delete data from influxdb?

I am adding this commands as reference for altering retention inside of InfluxDB container in kubernetes k8s. wget is used so as container doesn't have curl and influx CLI

wget 'localhost:8086/query?pretty=true' --post-data="db=k8s;q=ALTER RETENTION POLICY \"default\" on \"k8s\" duration 5h shard duration 4h default" -O-

Verification

wget 'localhost:8086/query?pretty=true' --post-data="db=k8s;q=SHOW RETENTION POLICIES" -O-

How to remove all callbacks from a Handler?

In my experience calling this worked great!

handler.removeCallbacksAndMessages(null);

In the docs for removeCallbacksAndMessages it says...

Remove any pending posts of callbacks and sent messages whose obj is token. If token is null, all callbacks and messages will be removed.

How to find the path of Flutter SDK

If you suppose unzipped the flutter zip file in folder called "Flutter". Your Flutter SDK Path will be <path_of_unzipped_file>\Flutter\flutter

HAX kernel module is not installed

Recently, I have faced this issue. And fixed it by changing CPU/ABI from Intel Atom (x86) to ARM(armeabi-v7a).

  • Select the Virtual Device. Click on Edit
  • Click on CPU/ABI option
  • Change it to ARM(armeabi-v7a) from intel. Click OK

Job done.

Pyspark: display a spark data frame in a table format

Let's say we have the following Spark DataFrame:

df = sqlContext.createDataFrame(
    [
        (1, "Mark", "Brown"), 
        (2, "Tom", "Anderson"), 
        (3, "Joshua", "Peterson")
    ], 
    ('id', 'firstName', 'lastName')
)

There are typically three different ways you can use to print the content of the dataframe:

Print Spark DataFrame

The most common way is to use show() function:

>>> df.show()
+---+---------+--------+
| id|firstName|lastName|
+---+---------+--------+
|  1|     Mark|   Brown|
|  2|      Tom|Anderson|
|  3|   Joshua|Peterson|
+---+---------+--------+

Print Spark DataFrame vertically

Say that you have a fairly large number of columns and your dataframe doesn't fit in the screen. You can print the rows vertically - For example, the following command will print the top two rows, vertically, without any truncation.

>>> df.show(n=2, truncate=False, vertical=True)
-RECORD 0-------------
 id        | 1        
 firstName | Mark     
 lastName  | Brown    
-RECORD 1-------------
 id        | 2        
 firstName | Tom      
 lastName  | Anderson 
only showing top 2 rows

Convert to Pandas and print Pandas DataFrame

Alternatively, you can convert your Spark DataFrame into a Pandas DataFrame using .toPandas() and finally print() it.

>>> df_pd = df.toPandas()
>>> print(df_pd)
   id firstName  lastName
0   1      Mark     Brown
1   2       Tom  Anderson
2   3    Joshua  Peterson

Note that this is not recommended when you have to deal with fairly large dataframes, as Pandas needs to load all the data into memory. If this is the case, the following configuration will help when converting a large spark dataframe to a pandas one:

spark.conf.set("spark.sql.execution.arrow.pyspark.enabled", "true")

For more details you can refer to my blog post Speeding up the conversion between PySpark and Pandas DataFrames

How to get a value from the last inserted row?

See the API docs for java.sql.Statement.

Basically, when you call executeUpdate() or executeQuery(), use the Statement.RETURN_GENERATED_KEYS constant. You can then call getGeneratedKeys to get the auto-generated keys of all rows created by that execution. (Assuming your JDBC driver provides it.)

It goes something along the lines of this:

Statement stmt = conn.createStatement();
stmt.execute(sql, Statement.RETURN_GENERATED_KEYS);
ResultSet keyset = stmt.getGeneratedKeys();

Error - is not marked as serializable

You need to add a Serializable attribute to the class which you want to serialize.

[Serializable]
public class OrgPermission

How do I change the default port (9000) that Play uses when I execute the "run" command?

With the commit introduced today (Nov 25), you can now specify a port number right after the run or start sbt commands.

For instance

play run 8080 or play start 8080

Play defaults to port 9000

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.

How to catch a click event on a button?

Just declare a method,e.g:if ur button id is button1 then,

button1.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Toast.makeText(Context, "Hello", Toast.LENGTH_SHORT).show();
        }
    });

If you want to make the imageview1 visible then in that method write:

imageview1.setVisibility(ImageView.VISIBLE);

Loop and get key/value pair for JSON array using jQuery

The best and perfect solution for this issue:

I tried the jQuery with the Ajax success responses, but it doesn't work so I invented my own and finally it works!

Click here to see the full solution

var rs = '{"test" : "Got it perfect!","message" : "Got it!"}';
eval("var toObject = "+ rs + ";");
alert(toObject.message);

Parse an URL in JavaScript

function parse_url(str, component) {
  //       discuss at: http://phpjs.org/functions/parse_url/
  //      original by: Steven Levithan (http://blog.stevenlevithan.com)
  // reimplemented by: Brett Zamir (http://brett-zamir.me)
  //         input by: Lorenzo Pisani
  //         input by: Tony
  //      improved by: Brett Zamir (http://brett-zamir.me)
  //             note: original by http://stevenlevithan.com/demo/parseuri/js/assets/parseuri.js
  //             note: blog post at http://blog.stevenlevithan.com/archives/parseuri
  //             note: demo at http://stevenlevithan.com/demo/parseuri/js/assets/parseuri.js
  //             note: Does not replace invalid characters with '_' as in PHP, nor does it return false with
  //             note: a seriously malformed URL.
  //             note: Besides function name, is essentially the same as parseUri as well as our allowing
  //             note: an extra slash after the scheme/protocol (to allow file:/// as in PHP)
  //        example 1: parse_url('http://username:password@hostname/path?arg=value#anchor');
  //        returns 1: {scheme: 'http', host: 'hostname', user: 'username', pass: 'password', path: '/path', query: 'arg=value', fragment: 'anchor'}

  var query, key = ['source', 'scheme', 'authority', 'userInfo', 'user', 'pass', 'host', 'port',
      'relative', 'path', 'directory', 'file', 'query', 'fragment'
    ],
    ini = (this.php_js && this.php_js.ini) || {},
    mode = (ini['phpjs.parse_url.mode'] &&
      ini['phpjs.parse_url.mode'].local_value) || 'php',
    parser = {
      php: /^(?:([^:\/?#]+):)?(?:\/\/()(?:(?:()(?:([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?))?()(?:(()(?:(?:[^?#\/]*\/)*)()(?:[^?#]*))(?:\?([^#]*))?(?:#(.*))?)/,
      strict: /^(?:([^:\/?#]+):)?(?:\/\/((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?))?((((?:[^?#\/]*\/)*)([^?#]*))(?:\?([^#]*))?(?:#(.*))?)/,
      loose: /^(?:(?![^:@]+:[^:@\/]*@)([^:\/?#.]+):)?(?:\/\/\/?)?((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?)(((\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?([^?#\/]*))(?:\?([^#]*))?(?:#(.*))?)/ // Added one optional slash to post-scheme to catch file:/// (should restrict this)
    };

  var m = parser[mode].exec(str),
    uri = {},
    i = 14;
  while (i--) {
    if (m[i]) {
      uri[key[i]] = m[i];
    }
  }

  if (component) {
    return uri[component.replace('PHP_URL_', '')
      .toLowerCase()];
  }
  if (mode !== 'php') {
    var name = (ini['phpjs.parse_url.queryKey'] &&
      ini['phpjs.parse_url.queryKey'].local_value) || 'queryKey';
    parser = /(?:^|&)([^&=]*)=?([^&]*)/g;
    uri[name] = {};
    query = uri[key[12]] || '';
    query.replace(parser, function($0, $1, $2) {
      if ($1) {
        uri[name][$1] = $2;
      }
    });
  }
  delete uri.source;
  return uri;
}

reference

How to parse a CSV file using PHP

Handy one liner to parse a CSV file into an array

$csv = array_map('str_getcsv', file('data.csv'));

Set NA to 0 in R

Why not try this

  na.zero <- function (x) {
        x[is.na(x)] <- 0
        return(x)
    }
    na.zero(df)

chart.js load totally new data

ChartJS 2.6 supports data reference replacement (see Note in update(config) documentation). So when you have your Chart, you could basically just do this:

myChart.data.labels = ['1am', '2am', '3am', '4am'];
myChart.data.datasets[0].data = [0, 12, 35, 36];
myChart.update();

It doesn't do the animation you'd get from adding points, but existing points on the graph will be animated.

How do I check out a specific version of a submodule using 'git submodule'?

Step 1: Add the submodule

   git submodule add git://some_repository.git some_repository

Step 2: Fix the submodule to a particular commit

By default the new submodule will be tracking HEAD of the master branch, but it will NOT be updated as you update your primary repository. In order to change the submodule to track a particular commit or different branch, change directory to the submodule folder and switch branches just like you would in a normal repository.

   git checkout -b some_branch origin/some_branch

Now the submodule is fixed on the development branch instead of HEAD of master.

From Two Guys Arguing — Tie Git Submodules to a Particular Commit or Branch .

How do I set up cron to run a file just once at a specific time?

Your comment suggests you're trying to call this from a programming language. If that's the case, can your program fork a child process that calls sleep then does the work?

What about having your program calculate the number of seconds until the desired runtime, and have it call shell_exec("sleep ${secondsToWait) ; myCommandToRun");

Sorting arrays in javascript by object key value

here's an example with the accepted answer:

 a = [{name:"alex"},{name:"clex"},{name:"blex"}];

For Ascending :

a.sort((a,b)=> (a.name > b.name ? 1 : -1))

output : [{name: "alex"}, {name: "blex"},{name: "clex"} ]

For Decending :

a.sort((a,b)=> (a.name < b.name ? 1 : -1))

output : [{name: "clex"}, {name: "blex"}, {name: "alex"}]

How to make a simple collection view with Swift

This project has been tested with Xcode 10 and Swift 4.2.

Create a new project

It can be just a Single View App.

Add the code

Create a new Cocoa Touch Class file (File > New > File... > iOS > Cocoa Touch Class). Name it MyCollectionViewCell. This class will hold the outlets for the views that you add to your cell in the storyboard.

import UIKit
class MyCollectionViewCell: UICollectionViewCell {
    
    @IBOutlet weak var myLabel: UILabel!
}

We will connect this outlet later.

Open ViewController.swift and make sure you have the following content:

import UIKit
class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {
    
    let reuseIdentifier = "cell" // also enter this string as the cell identifier in the storyboard
    var items = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35", "36", "37", "38", "39", "40", "41", "42", "43", "44", "45", "46", "47", "48"]
    
    
    // MARK: - UICollectionViewDataSource protocol
    
    // tell the collection view how many cells to make
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return self.items.count
    }
    
    // make a cell for each cell index path
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        
        // get a reference to our storyboard cell
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath as IndexPath) as! MyCollectionViewCell
        
        // Use the outlet in our custom class to get a reference to the UILabel in the cell
        cell.myLabel.text = self.items[indexPath.row] // The row value is the same as the index of the desired text within the array.
        cell.backgroundColor = UIColor.cyan // make cell more visible in our example project
        
        return cell
    }
    
    // MARK: - UICollectionViewDelegate protocol
    
    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        // handle tap events
        print("You selected cell #\(indexPath.item)!")
    }
}

Notes

  • UICollectionViewDataSource and UICollectionViewDelegate are the protocols that the collection view follows. You could also add the UICollectionViewFlowLayout protocol to change the size of the views programmatically, but it isn't necessary.
  • We are just putting simple strings in our grid, but you could certainly do images later.

Set up the storyboard

Drag a Collection View to the View Controller in your storyboard. You can add constraints to make it fill the parent view if you like.

enter image description here

Make sure that your defaults in the Attribute Inspector are also

  • Items: 1
  • Layout: Flow

The little box in the top left of the Collection View is a Collection View Cell. We will use it as our prototype cell. Drag a Label into the cell and center it. You can resize the cell borders and add constraints to center the Label if you like.

enter image description here

Write "cell" (without quotes) in the Identifier box of the Attributes Inspector for the Collection View Cell. Note that this is the same value as let reuseIdentifier = "cell" in ViewController.swift.

enter image description here

And in the Identity Inspector for the cell, set the class name to MyCollectionViewCell, our custom class that we made.

enter image description here

Hook up the outlets

  • Hook the Label in the collection cell to myLabel in the MyCollectionViewCell class. (You can Control-drag.)
  • Hook the Collection View delegate and dataSource to the View Controller. (Right click Collection View in the Document Outline. Then click and drag the plus arrow up to the View Controller.)

enter image description here

Finished

Here is what it looks like after adding constraints to center the Label in the cell and pinning the Collection View to the walls of the parent.

enter image description here

Making Improvements

The example above works but it is rather ugly. Here are a few things you can play with:

Background color

In the Interface Builder, go to your Collection View > Attributes Inspector > View > Background.

Cell spacing

Changing the minimum spacing between cells to a smaller value makes it look better. In the Interface Builder, go to your Collection View > Size Inspector > Min Spacing and make the values smaller. "For cells" is the horizontal distance and "For lines" is the vertical distance.

Cell shape

If you want rounded corners, a border, and the like, you can play around with the cell layer. Here is some sample code. You would put it directly after cell.backgroundColor = UIColor.cyan in code above.

cell.layer.borderColor = UIColor.black.cgColor
cell.layer.borderWidth = 1
cell.layer.cornerRadius = 8

See this answer for other things you can do with the layer (shadow, for example).

Changing the color when tapped

It makes for a better user experience when the cells respond visually to taps. One way to achieve this is to change the background color while the cell is being touched. To do that, add the following two methods to your ViewController class:

// change background color when user touches cell
func collectionView(_ collectionView: UICollectionView, didHighlightItemAt indexPath: IndexPath) {
    let cell = collectionView.cellForItem(at: indexPath)
    cell?.backgroundColor = UIColor.red
}

// change background color back when user releases touch
func collectionView(_ collectionView: UICollectionView, didUnhighlightItemAt indexPath: IndexPath) {
    let cell = collectionView.cellForItem(at: indexPath)
    cell?.backgroundColor = UIColor.cyan
}

Here is the updated look:

enter image description here

Further study

UITableView version of this Q&A

Unzip All Files In A Directory

If by 'current directory' you mean the directory in which the zip file is, then I would use this command:

find . -name '*.zip' -execdir unzip {} \; 

excerpt from find's man page

-execdir command ;
-execdir command {} +

Like -exec, but the specified command is run from the subdirectory containing the matched file, which is not normally the directory in which you started find. This a much more secure method for invoking commands, as it avoids race conditions during resolution of the paths to the matched files. As with the -exec option, the '+' form of -execdir will build a command line to process more than one matched file, but any given invocation of command will only list files that exist in the same subdirectory. If you use this option, you must ensure that your $PATH environment variable does not reference the current directory; otherwise, an attacker can run any commands they like by leaving an appropriately-named file in a directory in which you will run -execdir.

How to concatenate strings in django templates?

extends has no facility for this. Either put the entire template path in a context variable and use that, or copy the exist template tag and modify it appropriately.

Javascript get the text value of a column from a particular row of an html table

in case if your table has tbody

let tbl = document.getElementById("tbl").getElementsByTagName('tbody')[0];
console.log(tbl.rows[0].cells[0].innerHTML)

Convert pandas Series to DataFrame

to_frame():

Starting with the following Series, df:

email
[email protected]    A
[email protected]    B
[email protected]    C
dtype: int64

I use to_frame to convert the series to DataFrame:

df = df.to_frame().reset_index()

    email               0
0   [email protected]    A
1   [email protected]    B
2   [email protected]    C
3   [email protected]    D

Now all you need is to rename the column name and name the index column:

df = df.rename(columns= {0: 'list'})
df.index.name = 'index'

Your DataFrame is ready for further analysis.

Update: I just came across this link where the answers are surprisingly similar to mine here.

Angular.js How to change an elements css class on click and to remove all others

have you tried with a condition in ng-class like here : http://jsfiddle.net/DotDotDot/zvLvg/ ?

    <span id='1' ng-class='{"myclass":tog==1}' ng-click='tog=1'>span 1</span>
    <span id='2' ng-class='{"myclass":tog==2}' ng-click='tog=2'>span 2</span>

UnicodeEncodeError: 'ascii' codec can't encode character u'\u2013' in position 3 2: ordinal not in range(128)

I had the same problem. This work fine for me:

str(objdata).encode('utf-8')

Conditional Logic on Pandas DataFrame

In this specific example, where the DataFrame is only one column, you can write this elegantly as:

df['desired_output'] = df.le(2.5)

le tests whether elements are less than or equal 2.5, similarly lt for less than, gt and ge.

How to remove new line characters from data rows in mysql?

UPDATE mytable SET title=TRIM(REPLACE(REPLACE(title, "\n", ""), "\t", ""));

How to reset Android Studio

If you are using Windows and Android Studio 4 and above, the location to the directory is C:\Users(your name)\AppData\Roaming\Google\

Simple delete the Google folder to reset all settings. Open Android Studio and do not import settings when asked

What is the difference between Sprint and Iteration in Scrum and length of each Sprint?

Iteration is synonymous with sprint, sprint is just the Scrum terminology.

On the question about sprint length, the only caution I would note is that in Scrum you are using the past sprints to gain a level of predictability on your teams ability to deliver on their commitments for the sprint. They do this by developing a velocity over a number of sprints. A change in the team members or the length of the sprint are factors that will affect the velocity for a sprint, over past sprints.

Just as background, velocity is the sum of estimation points assigned to the backlog items, or stories, that were completely finished during that sprint. Most Agile proponents (Mike Cohn, Ken Schwaber and Jeff Sutherland for instance), recommend that teams use "the recent weather" to base their future estimations on how much they think they can commit to in a sprint. This means using the average from the last few sprints as the basis for an estimate in the upcoming sprint planning session.

Once again, varying the sprint length reduces your teams ability to provide that velocity statistic which the team uses for sprint planning, and the product owner uses for release planning (i.e. predicting when the project will end or what will be in the project at the end).

I recommend Mike Cohn's book on Agile Estimating and Planning to provide an overview of the way sprints, estimation and planning all can fit together.

MATLAB, Filling in the area between two sets of data, lines in one figure

Personally, I find it both elegant and convenient to wrap the fill function. To fill between two equally sized row vectors Y1 and Y2 that share the support X (and color C):

fill_between_lines = @(X,Y1,Y2,C) fill( [X fliplr(X)],  [Y1 fliplr(Y2)], C );

What's the difference between lists enclosed by square brackets and parentheses in Python?

The first is a list, the second is a tuple. Lists are mutable, tuples are not.

Take a look at the Data Structures section of the tutorial, and the Sequence Types section of the documentation.

How can I find last row that contains data in a specific column?

I would like to add one more reliable way using UsedRange to find the last used row:

lastRow = Sheet1.UsedRange.Row + Sheet1.UsedRange.Rows.Count - 1

Similarly to find the last used column you can see this

enter image description here

Result in Immediate Window:

?Sheet1.UsedRange.Row+Sheet1.UsedRange.Rows.Count-1
 21 

Pointers in C: when to use the ampersand and the asterisk?

Ok, looks like your post got editted...

double foo[4];
double *bar_1 = &foo[0];

See how you can use the & to get the address of the beginning of the array structure? The following

Foo_1(double *bar, int size){ return bar[size-1]; }
Foo_2(double bar[], int size){ return bar[size-1]; }

will do the same thing.

What exactly does the Access-Control-Allow-Credentials header do?

By default, CORS does not include cookies on cross-origin requests. This is different from other cross-origin techniques such as JSON-P. JSON-P always includes cookies with the request, and this behavior can lead to a class of vulnerabilities called cross-site request forgery, or CSRF.

In order to reduce the chance of CSRF vulnerabilities in CORS, CORS requires both the server and the client to acknowledge that it is ok to include cookies on requests. Doing this makes cookies an active decision, rather than something that happens passively without any control.

The client code must set the withCredentials property on the XMLHttpRequest to true in order to give permission.

However, this header alone is not enough. The server must respond with the Access-Control-Allow-Credentials header. Responding with this header to true means that the server allows cookies (or other user credentials) to be included on cross-origin requests.

You also need to make sure your browser isn't blocking third-party cookies if you want cross-origin credentialed requests to work.

Note that regardless of whether you are making same-origin or cross-origin requests, you need to protect your site from CSRF (especially if your request includes cookies).

convert array into DataFrame in Python

You can add parameter columns or use dict with key which is converted to column name:

np.random.seed(123)
e = np.random.normal(size=10)  
dataframe=pd.DataFrame(e, columns=['a']) 
print (dataframe)
          a
0 -1.085631
1  0.997345
2  0.282978
3 -1.506295
4 -0.578600
5  1.651437
6 -2.426679
7 -0.428913
8  1.265936
9 -0.866740

e_dataframe=pd.DataFrame({'a':e}) 
print (e_dataframe)
          a
0 -1.085631
1  0.997345
2  0.282978
3 -1.506295
4 -0.578600
5  1.651437
6 -2.426679
7 -0.428913
8  1.265936
9 -0.866740

Import and insert sql.gz file into database with putty

For an oneliner, on linux or cygwin, you need to do public key authentication on the host, otherwise ssh will be asking for password.


gunzip -c numbers.sql.gz | ssh user@host mysql --user=user_name --password=your_password db_name

Or do port forwarding and connect to the remote mysql using a "local" connection:

ssh -L some_port:host:local_mysql_port user@host

then do the mysql connection on your local machine to localhost:some_port.

The port forwarding will work from putty too, with the similar -L option or you can configure it from the settings panel, somewhere down on the tree.

Rendering a template variable as HTML

No need to use the filter or tag in template. Just use format_html() to translate variable to html and Django will automatically turn escape off for you variable.

format_html("<h1>Hello</h1>")

Check out here https://docs.djangoproject.com/en/3.0/ref/utils/#django.utils.html.format_html

In Excel, how do I extract last four letters of a ten letter string?

No need to use a macro. Supposing your first string is in A1.

=RIGHT(A1, 4)

Drag this down and you will get your four last characters.

Edit: To be sure, if you ever have sequences like 'ABC DEF' and want the last four LETTERS and not CHARACTERS you might want to use trimspaces()

=RIGHT(TRIMSPACES(A1), 4)

Edit: As per brettdj's suggestion, you may want to check that your string is actually 4-character long or more:

=IF(TRIMSPACES(A1)>=4, RIGHT(TRIMSPACES(A1), 4), TRIMSPACES(A1))

Datatable vs Dataset

One feature of the DataSet is that if you can call multiple select statements in your stored procedures, the DataSet will have one DataTable for each.

adding comment in .properties files

According to the documentation of the PropertyFile task, you can append the generated properties to an existing file. You could have a properties file with just the comment line, and have the Ant task append the generated properties.

Consistency of hashCode() on a Java string

I found something about JDK 1.0 and 1.1 and >= 1.2:

In JDK 1.0.x and 1.1.x the hashCode function for long Strings worked by sampling every nth character. This pretty well guaranteed you would have many Strings hashing to the same value, thus slowing down Hashtable lookup. In JDK 1.2 the function has been improved to multiply the result so far by 31 then add the next character in sequence. This is a little slower, but is much better at avoiding collisions. Source: http://mindprod.com/jgloss/hashcode.html

Something different, because you seem to need a number: How about using CRC32 or MD5 instead of hashcode and you are good to go - no discussions and no worries at all...

How to calculate number of days between two dates

Try:

//Difference in days

var diff =  Math.floor(( start - end ) / 86400000);
alert(diff);

ORACLE convert number to string

This should solve your problem:

select replace(to_char(a, '90D90'),'.00','')
from
(
select 50 a from dual
union
select 50.57 from dual
union
select 5.57 from dual
union
select 0.35 from dual
union
select 0.4 from dual
);

Give a look also as this SQL Fiddle for test.

Why won't my PHP app send a 404 error?

That is correct behaviour, it's up to you to create the contents for the 404 page.
The 404 header is used by spiders and download-managers to determine if the file exists.
(A page with a 404 header won't be indexed by google or other search-engines)

Normal users however don't look at http-headers and use the page as a normal page.

Parse JSON response using jQuery

Original question was to parse a list of topics, however starting with the original example to have a function return a single value may also useful. To that end, here is an example of (one way) to do that:

<script type='text/javascript'>
    function getSingleValueUsingJQuery() {
      var value = "";
      var url = "rest/endpointName/" + document.getElementById('someJSPFieldName').value;
      jQuery.ajax({
        type: 'GET',
        url: url,
        async: false,
        contentType: "application/json",
        dataType: 'json',
        success: function(json) {
          console.log(json.value);   // needs to match the payload (i.e. json must have {value: "foo"}
          value = json.value;
        },
        error: function(e) {
          console.log("jQuery error message = "+e.message);
        }
      });
      return value;
    }
    </script>
    

Why can't I use a list as a dict key in python?

A Dictionary is a HashMap it stores map of your keys, value converted to a hashed new key and value mapping.

something like (psuedo code):

{key : val}  
hash(key) = val

If you are wondering which are available options that can be used as key for your dictionary. Then

anything which is hashable(can be converted to hash, and hold static value i.e immutable so as to make a hashed key as stated above) is eligible but as list or set objects can be vary on the go so hash(key) should also needs to vary just to be in sync with your list or set.

You can try :

hash(<your key here>)

If it works fine it can be used as key for your dictionary or else convert it to something hashable.


Inshort :

  1. Convert that list to tuple(<your list>).
  2. Convert that list to str(<your list>).

Webdriver and proxy server for firefox

Preferences -> Advanced -> Network -> Connection (Configure how Firefox connects to the Internet)