Programs & Examples On #Linfu dynamicproxy

LinFu DynamicProxy is a library for generating proxies on the fly at runtime.

How do you cache an image in Javascript

I use a similar technique to lazyload images, but can't help but notice that Javascript doesn't access the browser cache on first loading.

My example:

I have a rotating banner on my homepage with 4 images the slider wait 2 seconds, than the javascript loads the next image, waits 2 seconds, etc.

These images have unique urls that change whenever I modify them, so they get caching headers that will cache in the browser for a year.

max-age: 31536000, public

Now when I open Chrome Devtools and make sure de 'Disable cache' option is not active and load the page for the first time (after clearing the cache) all images get fetch and have a 200 status. After a full cycle of all images in the banner the network requests stop and the cached images are used.

Now when I do a regular refresh or go to a subpage and click back, the images that are in the cache seems to be ignored. I would expect to see a grey message "from disk cache" in the Network tab of Chrome devtools. In instead I see the requests pass by every two seconds with a Green status circle instead of gray, I see data being transferred, so it I get the impression the cache is not accessed at all from javascript. It simply fetches the image each time the page gets loaded.

So each request to the homepage triggers 4 requests regardless of the caching policy of the image.

Considering the above together and the new http2 standard most webservers and browsers now support, I think it's better to stop using lazyloading since http2 will load all images nearly simultaneously.

If this is a bug in Chrome Devtools it really surprises my nobody noticed this yet. ;)

If this is true, using lazyloading only increases bandwith usage.

Please correct me if I'm wrong. :)

Create empty file using python

Of course there IS a way to create files without opening. It's as easy as calling os.mknod("newfile.txt"). The only drawback is that this call requires root privileges on OSX.

C++ Cout & Cin & System "Ambiguous"

This kind of thing doesn't just magically happen on its own; you changed something! In industry we use version control to make regular savepoints, so when something goes wrong we can trace back the specific changes we made that resulted in that problem.

Since you haven't done that here, we can only really guess. In Visual Studio, Intellisense (the technology that gives you auto-complete dropdowns and those squiggly red lines) works separately from the actual C++ compiler under the bonnet, and sometimes gets things a bit wrong.

In this case I'd ask why you're including both cstdlib and stdlib.h; you should only use one of them, and I recommend the former. They are basically the same header, a C header, but cstdlib puts them in the namespace std in order to "C++-ise" them. In theory, including both wouldn't conflict but, well, this is Microsoft we're talking about. Their C++ toolchain sometimes leaves something to be desired. Any time the Intellisense disagrees with the compiler has to be considered a bug, whichever way you look at it!

Anyway, your use of using namespace std (which I would recommend against, in future) means that std::system from cstdlib now conflicts with system from stdlib.h. I can't explain what's going on with std::cout and std::cin.

Try removing #include <stdlib.h> and see what happens.

If your program is building successfully then you don't need to worry too much about this, but I can imagine the false positives being annoying when you're working in your IDE.

How to clear browsing history using JavaScript?

Can you try using document.location.replace() it is used to clear the last entry in the history and replace it with the address of a new url. replace() removes the URL of the current document from the document history, meaning that it is not possible to use the "back" button to navigate back to the original document.

<script type="text/javascript">
    function Navigate(){   
         window.location.replace('your link');
        return false;


   <button onclick="Navigate()">Replace document</button>

AngularJS : When to use service instead of factory

Factory and Service are the most commonly used method. The only difference between them is that the Service method works better for objects that need inheritance hierarchy, while the Factory can produce JavaScript primitives and functions.

The Provider function is the core method and all the other ones are just syntactic sugar on it. You need it only if you are building a reusable piece of code that needs global configuration.

There are five methods to create services: Value, Factory, Service, Provider and Constant. You can learn more about this here angular service, this article explain all this methods with practical demo examples.


BAT file to map to network drive without running as admin

This .vbs code creates a .bat file with the current mapped network drives. Then, just put the created file into the machine which you want to re-create the mappings and double-click it. It will try to create all mappings using the same drive letters (errors can occur if any letter is in use). This method also can be used as a backup of the current mappings. Save the code bellow as a .vbs file (e.g. Mappings.vbs) and double-click it.

' ********** My Code **********
Set wshShell = CreateObject( "WScript.Shell" )

' ********** Get ComputerName
strComputer = wshShell.ExpandEnvironmentStrings( "%COMPUTERNAME%" )

' ********** Get Domain 
sUserDomain = createobject("").UserDomain

Set Connect = GetObject("winmgmts://"&strComputer)
Set WshNetwork = WScript.CreateObject("WScript.Network")
Set oDrives = WshNetwork.EnumNetworkDrives
Set oPrinters = WshNetwork.EnumPrinterConnections

' ********** Current Path
sCurrentPath = CreateObject("Scripting.FileSystemObject").GetParentFolderName(WScript.ScriptFullName)

' ********** Blank the report message
strMsg = ""

' ********** Set objects 
Set objWMIService = GetObject("winmgmts:" & "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
Set objWbem = GetObject("winmgmts:")
Set objRegistry = GetObject("winmgmts://" & strComputer & "/root/default:StdRegProv")

' ********** Get UserName
sUser = CreateObject("WScript.Network").UserName

' ********** Print user and computer
'strMsg = strMsg & "    User: " & sUser & VbCrLf
'strMsg = strMsg & "Computer: " & strComputer & VbCrLf & VbCrLf

strMsg = strMsg & "###  COPIED FROM " & strComputer & " ###" & VbCrLf& VbCrLf
strMsg = strMsg & "@echo off" & vbCrLf

For i = 0 to oDrives.Count - 1 Step 2
    strMsg = strMsg & "net use " & oDrives.Item(i) & " " & oDrives.Item(i+1) & " /user:" & sUserDomain & "\" & sUser & " /persistent:yes" & VbCrLf
strMsg = strMsg & ":exit" & VbCrLf
strMsg = strMsg & "@pause" & VbCrLf

' ********** write the file to disk.
strDirectory = sCurrentPath 
Set objFSO = CreateObject("Scripting.FileSystemObject")
If objFSO.FolderExists(strDirectory) Then
    ' Procede
    Set objFolder = objFSO.CreateFolder(strDirectory)
End if

' ********** Calculate date serial for filename **********
intMonth = month(now)
if intMonth < 10 then
    strThisMonth = "0" & intMonth
    strThisMonth = intMOnth
end if
intDay = Day(now)
if intDay < 10 then
    strThisDay = "0" & intDay
    strThisDay = intDay
end if
strFilenameDateSerial = year(now) & strThisMonth & strThisDay
    sFileName = strDirectory & "\" & strComputer & "_" & sUser & "_MappedDrives" & "_" & strFilenameDateSerial & ".bat"
    Set objFile = objFSO.CreateTextFile(sFileName,True) 
objFile.Write strMsg & vbCrLf

' ********** Ask to view file
strFinish = "End: A .bat was generated. " & VbCrLf & "Copy the generated file  (" & sFileName & ")  into the machine where you want to recreate the mappings and double-click it." & VbCrLf & VbCrLf 

GUI-based or Web-based JSON editor that works like property explorer

Update: In an effort to answer my own question, here is what I've been able to uncover so far. If anyone else out there has something, I'd still be interested to find out more.

Based on JSON Schema

Commercial (No endorsement intended or implied, may or may not meet requirement)



See Also

SELECT INTO Variable in MySQL DECLARE causes syntax error?

It is worth noting that despite the fact that you can SELECT INTO global variables like:


You can NOT use FETCH INTO global variables like:


Looks like it's not a bug. I hope it will be helpful to someone...

Pass variables to AngularJS controller, best practice?

You could use ng-init in an outer div:

<div ng-init="param='value';">
    <div ng-controller="BasketController" >
        <label>param: {{value}}</label>

The parameter will then be available in your controller's scope:

function BasketController($scope) {

Error :- java runtime environment JRE or java development kit must be available in order to run eclipse

This problem is because of the fact that eclipse is not able to find Java ,

Check the java directory cd /Library/Java/JavaVirtualMachines///Contents/Home/jre/bin

If thats not present down JDK from

Once JDK is installed change eclipse.ini file

On Mac: Right click on Eclipse icon and click "Show package Content"

Navigate to eclipse>Contents>Eclipse>eclipse.ini

Open the file and replace the java path after "-vm" with this


How to prevent a browser from storing passwords

At the time this was posted, neither of the previous answers worked for me.

This approach uses a visible password field to capture the password from the user and a hidden password field to pass the password to the server. The visible password field is blanked before the form is submitted, but not with a form submit event handler (see explanation on the next paragraph). This approach transfers the visible password field value to the hidden password field as soon as possible (without unnecessary overhead) and then wipes out the visible password field. If the user tabs back into the visible password field, the value is restored. It uses the placeholder to display ??? after the field was wiped out.

I tried clearing the visible password field on the form onsubmit event, but the browser seems to be inspecting the values before the event handler and prompts the user to save the password. Actually, if the alert at the end of passwordchange is uncommented, the browser still prompts to save the password.

function formsubmit(e) {
  document.getElementById('form_password').setAttribute('placeholder', 'password');

function userinputfocus(e) {
  //Just to make the browser mark the username field as required
  // like the password field does. =;

function passwordfocus(e) {'placeholder', 'password');'required', 'required'); = document.getElementById('password').value;

function passwordkeydown(e) {
  if (e.key === 'Enter') {

function passwordblur(e) {

  if (document.getElementById('password').value !== '') {
    var placeholder = '';
    for (i = 0; i < document.getElementById('password').value.length; i++) {
      placeholder = placeholder + '?';
    document.getElementById('form_password').setAttribute('placeholder', placeholder);
  } else {
    document.getElementById('form_password').setAttribute('placeholder', 'password');

function passwordchange(password) {
  if (password.getAttribute('placeholder') === 'password') {
    if (password.value === '') {
      password.setAttribute('required', 'required');
    } else {
      var placeholder = '';

      for (i = 0; i < password.value.length; i++) {
        placeholder = placeholder + '?';

    document.getElementById('password').value = password.value;
    password.value = '';

    //This alert will make the browser prompt for a password save
#form_password:not([placeholder='password'])::placeholder {
  color: red; /*change to black*/
  opacity: 1;
<form onsubmit="formsubmit(event)" action="/action_page.php">
<input type="hidden" id="password" name="password" />

<input type="text" id="username" name="username" required
  autocomplete="off" placeholder="username"
  onfocus="userinputfocus(event)" />
<input type="password" id="form_password" name="form_password" required
  autocomplete="off" placeholder="password"
<br />
<input type="submit"/>

Node.js getaddrinfo ENOTFOUND

I fixed this error with this

$ npm info express --verbose
# Error message: npm info retry will retry, error on last attempt: Error: getaddrinfo ENOTFOUND
$ nslookup

Non-authoritative answer:  canonical name =    canonical name =
$ sudo vim /etc/hosts 
# Add "` to hosts file
$ npm info express --verbose
# Works now!

Original source:

How do I lowercase a string in Python?

Use .lower() - For example:

s = "Kilometer"

The official 2.x documentation is here: str.lower()
The official 3.x documentation is here: str.lower()

How to get the selected item of a combo box to a string variable in c#

SelectedText = this.combobox.SelectionBoxItem.ToString();

How to import js-modules into TypeScript file?

You can import the whole module as follows:

import * as FriendCard from './../pages/FriendCard';

For more details please refer the modules section of Typescript official docs.

RESTful Authentication

I think restful authentication involves the passing of an authentication token as a parameter in the request. Examples are the use of apikeys by api's. I don't believe the use of cookies or http auth qualifies.

Domain Account keeping locking out with correct password every few minutes

I think this highlights a serious deficiency in Windows. We have a (techincal) user account that we use for our system consisting of a windows service and websites, with the app pools configured to run as this user.

Our company has a security policy that after 5 bad passwords, it locks the account out.

Now finding out what locks out the account is practically impossible in a enterprise. When the account is locked out, the AD server should log from what process and what server caused the lock out.

I've looked into it and it (lock out tools) and it doesnt do this. only possible thing is a tool but you have to run it on the server and wait to see if any process is doing it. But in a enterprise with 1000s of servers thats impossible, you have to guess. Its crazy.

What is resource-ref in web.xml used for?

You can always refer to resources in your application directly by their JNDI name as configured in the container, but if you do so, essentially you are wiring the container-specific name into your code. This has some disadvantages, for example, if you'll ever want to change the name later for some reason, you'll need to update all the references in all your applications, and then rebuild and redeploy them.

<resource-ref> introduces another layer of indirection: you specify the name you want to use in the web.xml, and, depending on the container, provide a binding in a container-specific configuration file.

So here's what happens: let's say you want to lookup the java:comp/env/jdbc/primaryDB name. The container finds that web.xml has a <resource-ref> element for jdbc/primaryDB, so it will look into the container-specific configuration, that contains something similar to the following:


Finally, it returns the object registered under the name of jdbc/PrimaryDBInTheContainer.

The idea is that specifying resources in the web.xml has the advantage of separating the developer role from the deployer role. In other words, as a developer, you don't have to know what your required resources are actually called in production, and as the guy deploying the application, you will have a nice list of names to map to real resources.

How to check if a file exists in a shell script

If you're using a NFS, "test" is a better solution, because you can add a timeout to it, in case your NFS is down:

time timeout 3 test -f 
real    0m3.004s <<== timeout is taken into account
user    0m0.001s
sys     0m0.004s
echo $?
124   <= 124 means the timeout has been reached

A "[ -e my_file ]" construct will freeze until the NFS is functional again:

if [ -e /nfs/my_nfs_is_currently_down ]; then echo "ok" else echo "ko" ; fi

<no answer from the system, my session is "frozen">

View content of H2 or HSQLDB in-memory database

With HSQLDB, you have several built-in options.

There are two GUI database managers and a command line interface to the database. The classes for these are:


You can start one of the above from your application and access the in-memory databases.

An example with JBoss is given here:

You can also start a server with your application, pointing it to an in-memory database.


Confused about __str__ on list in Python

print would work for you, although not that useful for you.

Your __str__ method will be more useful when you say want to print out a grid or struct representation as your program develops.

print self._grid.__str__()

def __str__(self):
    Return a string representation of the grid for debugging.
    grid_str = ""
    for row in range(self._rows):
        grid_str += str( self._grid[row] )
        grid_str += '\n'
    return grid_str

Use css gradient over background image

The accepted answer works well. Just for completeness (and since I like it's shortness), I wanted to share how to to it with compass (SCSS/SASS):

  $colorStart: rgba(0,0,0,0);
  $colorEnd: rgba(0,0,0,0.8);
  @include background-image(linear-gradient(to bottom, $colorStart, $colorEnd), url("bg.jpg"));

How to check if a JavaScript variable is NOT undefined?

var lastname = "Hi";

if(typeof lastname !== "undefined")
  alert("Hi. Variable is defined.");

Generating Random Number In Each Row In Oracle Query

Something like?

select t.*, round(dbms_random.value() * 8) + 1 from foo t;

Edit: David has pointed out this gives uneven distribution for 1 and 9.

As he points out, the following gives a better distribution:

select t.*, floor(dbms_random.value(1, 10)) from foo t;

PHP check file extension

  $original_str="this . is . to . find";
  echo "<br/> Position: ". $pos=strrpos($original_str, ".");
  if($pos >= 0)
    echo "<br/> Extension: ".   substr($original_str,$pos+1,$len-$pos) ;

Can't create a docker image for COPY failed: stat /var/lib/docker/tmp/docker-builder error

Another potential cause is that docker will not follow symbolic links by default (i.e don't use ln -s).

Find element in List<> that contains a value

Enumerable.First returns the element instead of an index. In both cases you will get an exception if no matching element appears in the list (your original code will throw an IndexOutOfBoundsException when you try to get the item at index -1, but First will throw an InvalidOperationException).

MyList.First(item => string.Equals("foo",

How to find out client ID of component for ajax update/render? Cannot find component with expression "foo" referenced from "bar"

Look in HTML output for actual client ID

You need to look in the generated HTML output to find out the right client ID. Open the page in browser, do a rightclick and View Source. Locate the HTML representation of the JSF component of interest and take its id as client ID. You can use it in an absolute or relative way depending on the current naming container. See following chapter.

Note: if it happens to contain iteration index like :0:, :1:, etc (because it's inside an iterating component), then you need to realize that updating a specific iteration round is not always supported. See bottom of answer for more detail on that.

Memorize NamingContainer components and always give them a fixed ID

If a component which you'd like to reference by ajax process/execute/update/render is inside the same NamingContainer parent, then just reference its own ID.

<h:form id="form">
    <p:commandLink update="result"> <!-- OK! -->
    <h:panelGroup id="result" />

If it's not inside the same NamingContainer, then you need to reference it using an absolute client ID. An absolute client ID starts with the NamingContainer separator character, which is by default :.

<h:form id="form">
    <p:commandLink update="result"> <!-- FAIL! -->
<h:panelGroup id="result" />
<h:form id="form">
    <p:commandLink update=":result"> <!-- OK! -->
<h:panelGroup id="result" />
<h:form id="form">
    <p:commandLink update=":result"> <!-- FAIL! -->
<h:form id="otherform">
    <h:panelGroup id="result" />
<h:form id="form">
    <p:commandLink update=":otherform:result"> <!-- OK! -->
<h:form id="otherform">
    <h:panelGroup id="result" />

NamingContainer components are for example <h:form>, <h:dataTable>, <p:tabView>, <cc:implementation> (thus, all composite components), etc. You recognize them easily by looking at the generated HTML output, their ID will be prepended to the generated client ID of all child components. Note that when they don't have a fixed ID, then JSF will use an autogenerated ID in j_idXXX format. You should absolutely avoid that by giving them a fixed ID. The OmniFaces NoAutoGeneratedIdViewHandler may be helpful in this during development.

If you know to find the javadoc of the UIComponent in question, then you can also just check in there whether it implements the NamingContainer interface or not. For example, the HtmlForm (the UIComponent behind <h:form> tag) shows it implements NamingContainer, but the HtmlPanelGroup (the UIComponent behind <h:panelGroup> tag) does not show it, so it does not implement NamingContainer. Here is the javadoc of all standard components and here is the javadoc of PrimeFaces.

Solving your problem

So in your case of:

<p:tabView id="tabs"><!-- This is a NamingContainer -->
    <p:tab id="search"><!-- This is NOT a NamingContainer -->
        <h:form id="insTable"><!-- This is a NamingContainer -->
            <p:dialog id="dlg"><!-- This is NOT a NamingContainer -->
                <h:panelGrid id="display">

The generated HTML output of <h:panelGrid id="display"> looks like this:

<table id="tabs:insTable:display">

You need to take exactly that id as client ID and then prefix with : for usage in update:

<p:commandLink update=":tabs:insTable:display">

Referencing outside include/tagfile/composite

If this command link is inside an include/tagfile, and the target is outside it, and thus you don't necessarily know the ID of the naming container parent of the current naming container, then you can dynamically reference it via UIComponent#getNamingContainer() like so:

<p:commandLink update=":#{component.namingContainer.parent.namingContainer.clientId}:display">

Or, if this command link is inside a composite component and the target is outside it:

<p:commandLink update=":#{cc.parent.namingContainer.clientId}:display">

Or, if both the command link and target are inside same composite component:

<p:commandLink update=":#{cc.clientId}:display">

See also Get id of parent naming container in template for in render / update attribute

How does it work under the covers

This all is specified as "search expression" in the UIComponent#findComponent() javadoc:

A search expression consists of either an identifier (which is matched exactly against the id property of a UIComponent, or a series of such identifiers linked by the UINamingContainer#getSeparatorChar character value. The search algorithm should operates as follows, though alternate alogrithms may be used as long as the end result is the same:

  • Identify the UIComponent that will be the base for searching, by stopping as soon as one of the following conditions is met:
    • If the search expression begins with the the separator character (called an "absolute" search expression), the base will be the root UIComponent of the component tree. The leading separator character will be stripped off, and the remainder of the search expression will be treated as a "relative" search expression as described below.
    • Otherwise, if this UIComponent is a NamingContainer it will serve as the basis.
    • Otherwise, search up the parents of this component. If a NamingContainer is encountered, it will be the base.
    • Otherwise (if no NamingContainer is encountered) the root UIComponent will be the base.
  • The search expression (possibly modified in the previous step) is now a "relative" search expression that will be used to locate the component (if any) that has an id that matches, within the scope of the base component. The match is performed as follows:
    • If the search expression is a simple identifier, this value is compared to the id property, and then recursively through the facets and children of the base UIComponent (except that if a descendant NamingContainer is found, its own facets and children are not searched).
    • If the search expression includes more than one identifier separated by the separator character, the first identifier is used to locate a NamingContainer by the rules in the previous bullet point. Then, the findComponent() method of this NamingContainer will be called, passing the remainder of the search expression.

Note that PrimeFaces also adheres the JSF spec, but RichFaces uses "some additional exceptions".

"reRender" uses UIComponent.findComponent() algorithm (with some additional exceptions) to find the component in the component tree.

Those additional exceptions are nowhere in detail described, but it's known that relative component IDs (i.e. those not starting with :) are not only searched in the context of the closest parent NamingContainer, but also in all other NamingContainer components in the same view (which is a relatively expensive job by the way).

Never use prependId="false"

If this all still doesn't work, then verify if you aren't using <h:form prependId="false">. This will fail during processing the ajax submit and render. See also this related question: UIForm with prependId="false" breaks <f:ajax render>.

Referencing specific iteration round of iterating components

It was for long time not possible to reference a specific iterated item in iterating components like <ui:repeat> and <h:dataTable> like so:

<h:form id="form">
    <ui:repeat id="list" value="#{['one','two','three']}" var="item">
        <h:outputText id="item" value="#{item}" /><br/>

    <h:commandButton value="Update second item">
        <f:ajax render=":form:list:1:item" />

However, since Mojarra 2.2.5 the <f:ajax> started to support it (it simply stopped validating it; thus you would never face the in the question mentioned exception anymore; another enhancement fix is planned for that later).

This only doesn't work yet in current MyFaces 2.2.7 and PrimeFaces 5.2 versions. The support might come in the future versions. In the meanwhile, your best bet is to update the iterating component itself, or a parent in case it doesn't render HTML, like <ui:repeat>.

When using PrimeFaces, consider Search Expressions or Selectors

PrimeFaces Search Expressions allows you to reference components via JSF component tree search expressions. JSF has several builtin:

  • @this: current component
  • @form: parent UIForm
  • @all: entire document
  • @none: nothing

PrimeFaces has enhanced this with new keywords and composite expression support:

  • @parent: parent component
  • @namingcontainer: parent UINamingContainer
  • @widgetVar(name): component as identified by given widgetVar

You can also mix those keywords in composite expressions such as @form:@parent, @this:@parent:@parent, etc.

PrimeFaces Selectors (PFS) as in @(.someclass) allows you to reference components via jQuery CSS selector syntax. E.g. referencing components having all a common style class in the HTML output. This is particularly helpful in case you need to reference "a lot of" components. This only prerequires that the target components have all a client ID in the HTML output (fixed or autogenerated, doesn't matter). See also How do PrimeFaces Selectors as in update="@(.myClass)" work?

Checking for a null object in C++

You can use a special designated object as the null object in case of references as follows:

class SomeClass

        int operator==(SomeClass &object)
            if(this == &object) 
                    return true;

            return false;

    static SomeClass NullObject;

SomeClass SomeClass::NullObject;

void print(SomeClass &val)
    if(val == SomeClass::NullObject)
        printf("\nNOT NULL");

How do I scroll the UIScrollView when the keyboard appears?

Apple's recommendation recoded in Swift + Using UIScrollView with Auto Layout in iOS (basing on these following links: link 1, link 2, link 3):

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet var t1: UITextField!
    @IBOutlet var t2: UITextField!
    @IBOutlet var t3: UITextField!
    @IBOutlet var t4: UITextField!

    @IBOutlet var srcScrollView: UIScrollView!

    @IBOutlet var contentView: UIView!

    var contentViewCoordinates: CGPoint!

    override func viewDidLoad() {

        // Do any additional setup after loading the view, typically from a nib.

        /* Constraints on content view */
        let leftConstraint = NSLayoutConstraint(item:self.contentView,

        let rightConstraint = NSLayoutConstraint(item:self.contentView,

        /* Tap gesture */
        let tapGesture: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "hideKeyboard")
        // prevents the scroll view from swallowing up the touch event of child buttons
        tapGesture.cancelsTouchesInView = false

        /* Save content view coordinates */
        contentViewCoordinates = contentView.frame.origin

    func hideKeyboard() {

    var activeField: UITextField?

    func textFieldDidBeginEditing(textField: UITextField) {
        activeField = textField

    func textFieldDidEndEditing(textField: UITextField) {
        activeField = nil

    override func viewWillAppear(animated: Bool) {
        let center = NSNotificationCenter.defaultCenter()
        center.addObserver(self, selector: "keyboardOnScreen:", name: UIKeyboardDidShowNotification, object: nil)
        center.addObserver(self, selector: "keyboardOffScreen:", name: UIKeyboardDidHideNotification, object: nil)

    func keyboardOnScreen(notification: NSNotification){
        // Retrieve the size and top margin (inset is the fancy word used by Apple) 
        // of the keyboard displayed.
        let info: NSDictionary  = notification.userInfo!
        let kbSize = info.valueForKey(UIKeyboardFrameEndUserInfoKey)?.CGRectValue().size
        let contentInsets: UIEdgeInsets  = UIEdgeInsetsMake(0.0, 0.0, kbSize!.height, 0.0)

        srcScrollView.contentInset = contentInsets
        srcScrollView.scrollIndicatorInsets = contentInsets

        var aRect: CGRect = self.view.frame
        aRect.size.height -= kbSize!.height
        //you may not need to scroll, see if the active field is already visible
        if (CGRectContainsPoint(aRect, activeField!.frame.origin) == false) {
            let scrollPoint:CGPoint = CGPointMake(0.0, activeField!.frame.origin.y - kbSize!.height)
            srcScrollView.setContentOffset(scrollPoint, animated: true)

//    func keyboardOnScreen(aNotification: NSNotification) {
//        let info: NSDictionary  = aNotification.userInfo!
//        let kbSize = info.valueForKey(UIKeyboardFrameEndUserInfoKey)?.CGRectValue().size
//        var bkgndRect: CGRect! = activeField?.superview?.frame
//        bkgndRect.size.height += kbSize!.height
//        activeField?.superview?.frame = bkgndRect
//        srcScrollView.setContentOffset(CGPointMake(0.0, activeField!.frame.origin.y - kbSize!.height), animated: true)
//    }

    func keyboardOffScreen(notification: NSNotification){
        let contentInsets:UIEdgeInsets = UIEdgeInsetsZero

        srcScrollView.contentInset = contentInsets
        srcScrollView.scrollIndicatorInsets = contentInsets

        self.srcScrollView.setContentOffset(CGPointMake(0, -self.view.frame.origin.y/2), animated: true)


Converting any object to a byte array in java

What you want to do is called "serialization". There are several ways of doing it, but if you don't need anything fancy I think using the standard Java object serialization would do just fine.

Perhaps you could use something like this?

package com.example;


public class Serializer {

    public static byte[] serialize(Object obj) throws IOException {
        try(ByteArrayOutputStream b = new ByteArrayOutputStream()){
            try(ObjectOutputStream o = new ObjectOutputStream(b)){
            return b.toByteArray();

    public static Object deserialize(byte[] bytes) throws IOException, ClassNotFoundException {
        try(ByteArrayInputStream b = new ByteArrayInputStream(bytes)){
            try(ObjectInputStream o = new ObjectInputStream(b)){
                return o.readObject();


There are several improvements to this that can be done. Not in the least the fact that you can only read/write one object per byte array, which might or might not be what you want.

Note that "Only objects that support the interface can be written to streams" (see

Since you might run into it, the continuous allocation and resizing of the might turn out to be quite the bottle neck. Depending on your threading model you might want to consider reusing some of the objects.

For serialization of objects that do not implement the Serializable interface you either need to write your own serializer, for example using the read*/write* methods of and the get*/put* methods of java.nio.ByteBuffer perhaps together with reflection, or pull in a third party dependency.

This site has a list and performance comparison of some serialization frameworks. Looking at the APIs it seems Kryo might fit what you need.

How to get back Lost phpMyAdmin Password, XAMPP

Unless you have changed your password the default setting dont require you to enter a password to connect to the MYSQL server, try:


if not then you can export your databases to a external file, just follow these instructions.

if you are unable to access phpMyAdmin then try,

Get all child elements

Yes, you can use find_elements_by_ to retrieve children elements into a list. See the python bindings here:

Example HTML:

<ul class="bar">

You can use the find_elements_by_ like so:

parentElement = driver.find_element_by_class_name("bar")
elementList = parentElement.find_elements_by_tag_name("li")

If you want help with a specific case, you can edit your post with the HTML you're looking to get parent and children elements from.

Spring 3 MVC accessing HttpRequest from controller

@RequestMapping(value="/") public String home(HttpServletRequest request){
    System.out.println("My Attribute :: "+request.getAttribute("YourAttributeName"));
    return "home"; 

Class has been compiled by a more recent version of the Java Environment

I had a similar issue from the console after building a Jar in Intellij. Using the Java configuration to update to a newer version (Windows -> Configure Java -> Update -> Update Now) didn't work and stuck at version 1.8 (Java 8).

To switch to a more recent version locally I had to install the Java 15 JDK from and add that to my Java runtime environment settings.

Java Runtime Environment Settings

laravel 5.3 new Auth::routes()

if you are in laravel 5.7 and above Auth::routes(['register' => false]); in web.php

more possible options are as:

  'register' => false, // Routes of Registration
  'reset' => false,    // Routes of Password Reset
  'verify' => false,   // Routes of Email Verification

Multiple line comment in Python

#Single line


multi-line comment

com.sun.jdi.InvocationException occurred invoking method

I had the same issue once. In my case toString() method was badly created. TO be precise a static final variable was included in the toString method when a developer form my team was assigned code cleaning task and to add toString(), hashCode() code and equals() methods to domain objects where ever possible. but in of the classes because of over looking at it, he included final static variable that caused the "com.sun.jdi.InvocationException" this exception was visible on debugging only when I hovered over the object which has the exception.

Get min and max value in PHP Array

$num = array (0 => array ('id' => '20110209172713', 'Date' => '2011-02-09', 'Weight' => '200'),
          1 => array ('id' => '20110209172747', 'Date' => '2011-02-09', 'Weight' => '180'),
          2 => array ('id' => '20110209172827', 'Date' => '2011-02-09', 'Weight' => '175'),
          3 => array ('id' => '20110211204433', 'Date' => '2011-02-11', 'Weight' => '195'));

    foreach($num as $key => $val)   
        $weight[] = $val['Weight'];

     echo max($weight);
     echo min($weight);

Java: Convert a String (representing an IP) to InetAddress

Simply call InetAddress.getByName(String host) passing in your textual IP address.

From the javadoc: The host name can either be a machine name, such as "", or a textual representation of its IP address.

InetAddress javadoc

angular2: Error: TypeError: Cannot read property '...' of undefined

That's because abc is undefined at the moment of the template rendering. You can use safe navigation operator (?) to "protect" template until HTTP call is completed:


You can read more about safe navigation operator here.


Safe navigation operator can't be used in arrays, you will have to take advantage of NgIf directive to overcome this problem:

<div *ngIf="arr && arr.length > 0">

Read more about NgIf directive here.

Eclipse error: indirectly referenced from required .class files?

When i use a new eclipse version and try to use the previous workspace which i used with old eclipse version, this error occured.

Here is how i solve the problem:

Right click my project on Package Explorer -> Properties -> Java Build Path -> Libraries -> I see an error(Cross Sign) on JRE System Library. Because the path cannot be found. -> Double click the JRE System Library -> Select the option "Workspace Default JRE" -> Finish -> OK. -> BUM IT IS WORKING


Creating a search form in PHP to search a database?

try this out let me know what happens.


<form action="form.php" method="post"> 
Search: <input type="text" name="term" /><br /> 
<input type="submit" value="Submit" /> 


$term = mysql_real_escape_string($_REQUEST['term']);    

$sql = "SELECT * FROM liam WHERE Description LIKE '%".$term."%'";
$r_query = mysql_query($sql);

while ($row = mysql_fetch_array($r_query)){ 
echo 'Primary key: ' .$row['PRIMARYKEY']; 
echo '<br /> Code: ' .$row['Code']; 
echo '<br /> Description: '.$row['Description']; 
echo '<br /> Category: '.$row['Category']; 
echo '<br /> Cut Size: '.$row['CutSize'];  

Edit: Cleaned it up a little more.

Final Cut (my test file):

$db_hostname = 'localhost';
$db_username = 'demo';
$db_password = 'demo';
$db_database = 'demo';

// Database Connection String
$con = mysql_connect($db_hostname,$db_username,$db_password);
if (!$con)
  die('Could not connect: ' . mysql_error());

mysql_select_db($db_database, $con);

<!DOCTYPE html>
<html lang="en">
        <meta charset="utf-8" />
<form action="" method="post">  
Search: <input type="text" name="term" /><br />  
<input type="submit" value="Submit" />  
if (!empty($_REQUEST['term'])) {

$term = mysql_real_escape_string($_REQUEST['term']);     

$sql = "SELECT * FROM liam WHERE Description LIKE '%".$term."%'"; 
$r_query = mysql_query($sql); 

while ($row = mysql_fetch_array($r_query)){  
echo 'Primary key: ' .$row['PRIMARYKEY'];  
echo '<br /> Code: ' .$row['Code'];  
echo '<br /> Description: '.$row['Description'];  
echo '<br /> Category: '.$row['Category'];  
echo '<br /> Cut Size: '.$row['CutSize'];   


How to add manifest permission to an application?

I am late but i want to complete the answer.

An permission is added in manifest.xml like

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

This is enough for standard permissions where no permission is prompted to the user. However, it is not enough to add permission only to manifest if it is a dangerous permission. See android doc. Like Camera, Storage permissions.

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

You will need to ask permission from user. I use RxPermission library that is widely used library for asking permission. Because it is long code which we have to write to ask permission.

RxPermissions rxPermissions = new RxPermissions(this); // where this is an Activity instance // Must be done during an initialization phase like onCreate
    .subscribe(granted -> {
        if (granted) { // Always true pre-M
           // I can control the camera now
        } else {
           // Oups permission denied

Add this library to your app

allprojects {
    repositories {
        maven { url '' }

dependencies {
    implementation 'com.github.tbruyelle:rxpermissions:0.10.1'
    implementation 'com.jakewharton.rxbinding2:rxbinding:2.1.1'

Check if string contains a value in array

I think that a faster way is to use preg_match.

$user_input = 'Something or other';
$owned_urls_array = array('', '', '');

if ( preg_match('('.implode('|',$owned_urls_array).')', $user_input)){
    echo "Match found"; 
    echo "Match not found";

How-to turn off all SSL checks for postman for a specific site

enter image description here

click here in settings, one pop up window will get open. There we have switcher to make SSL verification certificate (Off)

How to draw vectors (physical 2D/3D vectors) in MATLAB?

I'm not sure of a way to do this in 3D, but in 2D you can use the compass command.

How do Python's any and all functions work?

How do Python's any and all functions work?

any and all take iterables and return True if any and all (respectively) of the elements are True.

>>> any([0, 0.0, False, (), '0']), all([1, 0.0001, True, (False,)])
(True, True)            #   ^^^-- truthy non-empty string
>>> any([0, 0.0, False, (), '']), all([1, 0.0001, True, (False,), {}])
(False, False)                                                #   ^^-- falsey

If the iterables are empty, any returns False, and all returns True.

>>> any([]), all([])
(False, True)

I was demonstrating all and any for students in class today. They were mostly confused about the return values for empty iterables. Explaining it this way caused a lot of lightbulbs to turn on.

Shortcutting behavior

They, any and all, both look for a condition that allows them to stop evaluating. The first examples I gave required them to evaluate the boolean for each element in the entire list.

(Note that list literal is not itself lazily evaluated - you could get that with an Iterator - but this is just for illustrative purposes.)

Here's a Python implementation of any and all:

def any(iterable):
    for i in iterable:
        if i:
            return True
    return False # for an empty iterable, any returns False!

def all(iterable):
    for i in iterable:
        if not i:
            return False
    return True  # for an empty iterable, all returns True!

Of course, the real implementations are written in C and are much more performant, but you could substitute the above and get the same results for the code in this (or any other) answer.


all checks for elements to be False (so it can return False), then it returns True if none of them were False.

>>> all([1, 2, 3, 4])                 # has to test to the end!
>>> all([0, 1, 2, 3, 4])              # 0 is False in a boolean context!
False  # ^--stops here!
>>> all([])
True   # gets to end, so True!


The way any works is that it checks for elements to be True (so it can return True), then it returnsFalseif none of them wereTrue`.

>>> any([0, 0.0, '', (), [], {}])     # has to test to the end!
>>> any([1, 0, 0.0, '', (), [], {}])  # 1 is True in a boolean context!
True   # ^--stops here!
>>> any([])
False   # gets to end, so False!

I think if you keep in mind the short-cutting behavior, you will intuitively understand how they work without having to reference a Truth Table.

Evidence of all and any shortcutting:

First, create a noisy_iterator:

def noisy_iterator(iterable):
    for i in iterable:
        print('yielding ' + repr(i))
        yield i

and now let's just iterate over the lists noisily, using our examples:

>>> all(noisy_iterator([1, 2, 3, 4]))
yielding 1
yielding 2
yielding 3
yielding 4
>>> all(noisy_iterator([0, 1, 2, 3, 4]))
yielding 0

We can see all stops on the first False boolean check.

And any stops on the first True boolean check:

>>> any(noisy_iterator([0, 0.0, '', (), [], {}]))
yielding 0
yielding 0.0
yielding ''
yielding ()
yielding []
yielding {}
>>> any(noisy_iterator([1, 0, 0.0, '', (), [], {}]))
yielding 1

The source

Let's look at the source to confirm the above.

Here's the source for any:

static PyObject *
builtin_any(PyObject *module, PyObject *iterable)
    PyObject *it, *item;
    PyObject *(*iternext)(PyObject *);
    int cmp;

    it = PyObject_GetIter(iterable);
    if (it == NULL)
        return NULL;
    iternext = *Py_TYPE(it)->tp_iternext;

    for (;;) {
        item = iternext(it);
        if (item == NULL)
        cmp = PyObject_IsTrue(item);
        if (cmp < 0) {
            return NULL;
        if (cmp > 0) {
    if (PyErr_Occurred()) {
        if (PyErr_ExceptionMatches(PyExc_StopIteration))
            return NULL;

And here's the source for all:

static PyObject *
builtin_all(PyObject *module, PyObject *iterable)
    PyObject *it, *item;
    PyObject *(*iternext)(PyObject *);
    int cmp;

    it = PyObject_GetIter(iterable);
    if (it == NULL)
        return NULL;
    iternext = *Py_TYPE(it)->tp_iternext;

    for (;;) {
        item = iternext(it);
        if (item == NULL)
        cmp = PyObject_IsTrue(item);
        if (cmp < 0) {
            return NULL;
        if (cmp == 0) {
    if (PyErr_Occurred()) {
        if (PyErr_ExceptionMatches(PyExc_StopIteration))
            return NULL;

C# static class why use?

Making a class static just prevents people from trying to make an instance of it. If all your class has are static members it is a good practice to make the class itself static.

Extract regression coefficient values

A summary.lm object stores these values in a matrix called 'coefficients'. So the value you are after can be accessed with:

a2Pval <- summary(mg)$coefficients[2, 4]

Or, more generally/readably, coef(summary(mg))["a2","Pr(>|t|)"]. See here for why this method is preferred.

Select where count of one field is greater than one

You can also do this with a self-join:

SELECT t1.* FROM db.table t1
JOIN db.table t2 ON t1.someField = t2.someField AND !=

Test if string is URL encoded in PHP

@user187291 code works and only fails when + is not encoded.

I know this is very old post. But this worked to me.

$is_encoded = preg_match('~%[0-9A-F]{2}~i', $string);
if($is_encoded) {
 $string  = urlencode(urldecode(str_replace(['+','='], ['%2B','%3D'], $string)));
} else {
  $string = urlencode($string);

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". in a Maven Project



slf4j-log4j12 is the log4j binding for slf4j you dont need to add another log4j dependency.

Provide the log4j configuration in and add it to your class path. There are sample configurations here

or you can change your binding to


if you are configuring slf4j due to some dependencies requiring it.

Padding a table row

The trick is to give padding on the td elements, but make an exception for the first (yes, it's hacky, but sometimes you have to play by the browser's rules):

td {

td:first-child {

First-child is relatively well supported:

You can use the same reasoning for the horizontal padding by using tr:first-child td.

Alternatively, exclude the first column by using the not operator. Support for this is not as good right now, though.

td:not(:first-child) {

How can I reverse a list in Python?

for e in reversed(array):
  print e

How can I run a windows batch file but hide the command window?

This little VBScript from technet does the trick:


strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
    & "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
Set objStartup = objWMIService.Get("Win32_ProcessStartup")

Set objConfig = objStartup.SpawnInstance_
objConfig.ShowWindow = HIDDEN_WINDOW
Set objProcess = GetObject("winmgmts:root\cimv2:Win32_Process")
errReturn = objProcess.Create("mybatch.bat", null, objConfig, intProcessID)

Edit mybatch.bat to your bat file name, save as a vbs, run it.

Doc says it's not tested in Win7, but I just tested it, it works fine. Won't show any window for whatever process you run

How do I tell Spring Boot which main class to use for the executable jar?

I tried the following code in pom.xml and it worked for me


center a row using Bootstrap 3

I use text-align-center in a row like this

<div class="row tac">
    <h1>Centered content</h1>

 .tac { text-align: center}

ReferenceError: fetch is not defined

The fetch API is not implemented in Node.

You need to use an external module for that, like node-fetch.

Install it in your Node application like this

npm i node-fetch --save

then put the line below at the top of the files where you are using the fetch API:

const fetch = require("node-fetch");

Can I add a custom attribute to an HTML tag?

Yes, you can use data-* attribute. The data-* attribute is used to store custom data private to the page or application.

    <li data-pageNumber="1"> 1 </li>
    <li data-pageNumber="2"> 2 </li>  
    <li data-pageNumber="3"> 3 </li>  

How do I create directory if it doesn't exist to create a file?

An elegant way to move your file to an nonexistent directory is to create the following extension to native FileInfo class:

public static class FileInfoExtension
    //second parameter is need to avoid collision with native MoveTo
    public static void MoveTo(this FileInfo file, string destination, bool autoCreateDirectory) { 

        if (autoCreateDirectory)
            var destinationDirectory = new DirectoryInfo(Path.GetDirectoryName(destination));

            if (!destinationDirectory.Exists)


Then use brand new MoveTo extension:

 using <namespace of FileInfoExtension>;
 new FileInfo("some path")
     .MoveTo("target path",true);

Check Methods extension documentation.

Getting the class name from a static method in Java

A refactoring-safe, cut&paste-safe solution that avoids the definition of ad-hoc classes below.

Write a static method that recover the class name having care to include the class name in the method name:

private static String getMyClassName(){
  return MyClass.class.getName();

then recall it in your static method:

public static void myMethod(){
  Tracer.debug(getMyClassName(), "message");

Refactoring safety is given by avoiding the use of strings, cut&paste safety is granted because if you cut&paste the caller method you won't find the getMyClassName() in the target "MyClass2" class, so you will be forced to redefine and update it.

Composer killed while updating

The "Killed" message usually means your process consumed too much memory, so you may simply need to add more memory to your system if possible. At the time of writing this answer, I've had to increase my virtual machine's memory to at least 768MB in order to get composer update to work in some situations.

However, if you're doing this on a live server, you shouldn't be using composer update at all. What you should instead do is:

  1. Run composer update in a local environment (such as directly on your physical laptop/desktop, or a docker container/VM running on your laptop/desktop) where memory limitations shouldn't be as severe.
  2. Upload or git push the composer.lock file.
  3. Run composer install on the live server.

composer install will then read from the .lock file, fetching the exact same versions every time rather than finding the latest versions of every package. This makes your app less likely to break, and composer uses less memory.

Read more here:

Alternatively, you can upload the entire vendor directory to the server, bypassing the need to run composer install at all, but then you should run composer dump-autoload --optimize.

Format a BigDecimal as String with max 2 decimal digits, removing 0 on decimal part

The below code may help you.

protected String getLocalizedBigDecimalValue(BigDecimal input, Locale locale) {
    final NumberFormat numberFormat = NumberFormat.getNumberInstance(locale);
    return numberFormat.format(input);

How to get domain URL and application name?

The application name come from getContextPath.

I find this graphic from Agile Software Craftsmanship HttpServletRequest Path Decoding sorts out all the different methods that are available:

enter image description here

Fastest way to implode an associative array with keys

echo implode(",", array_keys($companies->toArray()));

$companies->toArray() -- this is just in case if your $variable is an object, otherwise just pass $companies.

That's it!

Differences between hard real-time, soft real-time, and firm real-time?

Hard real time systems uses preemptive version of priority scheduling, so that critical tasks get immediately scheduled, whereas soft real time systems uses non-preemptive version of the priority scheduling, which allows the present task to be finished before control is transferred to the higher priority task, causing additional delays. Thus the task deadlines are critically followed in Hard real time systems, whereas in soft real time systems they are handled not that seriously.

Make div stay at bottom of page's content all the time even when there are scrollbars

Just worked out for another solution as above example have bug( somewhere error ) for me. Variation from the selected answer.

html,body {
    height: 100%

#nonFooter {
    min-height: 100%;
    /* Firefox */
    min-height: -moz-calc(100% - 30px);
    /* WebKit */
    min-height: -webkit-calc(100% - 30px);
    /* Opera */
    min-height: -o-calc(100% - 30px);
    /* Standard */
    min-height: calc(100% - 30px);

#footer {
    margin: 0;
    clear: both;
    position: relative;

for html layout

    <div id="nonFooter">header,middle,left,right,etc</div>
    <div id="footer"></div>

Well this way don't support old browser however its acceptable for old browser to scrolldown 30px to view the footer

Onclick CSS button effect

JS provides the tools to do this the right way. Try the demo snippet.

enter image description here

var doc = document;_x000D_
var buttons = doc.getElementsByTagName('button');_x000D_
var button = buttons[0];_x000D_
button.addEventListener("mouseover", function(){_x000D_
button.addEventListener("mouseout", function(){_x000D_
button.addEventListener("mousedown", function(){_x000D_
button.addEventListener("mouseup", function(){_x000D_
  alert('Button Clicked!');_x000D_
//this is unrelated to button styling.  It centers the button._x000D_
var box = doc.getElementById('box');_x000D_
var boxHeight = window.innerHeight;_x000D_ = boxHeight + 'px'; 
  text-transform: uppercase;_x000D_
  background-color:rgba(66, 66, 66,0.3);_x000D_
  -webkit-box-shadow: 0px 10px 5px -4px rgba(0,0,0,0.33);_x000D_
  -moz-box-shadow: 0px 10px 5px -4px rgba(0,0,0,0.33);_x000D_
  box-shadow: 0px 10px 5px -4px rgba(0,0,0,0.33);_x000D_
button:focus {_x000D_
  background-color:rgba(66, 66, 66,0.34);_x000D_
  -webkit-box-shadow: 0px 6px 5px -4px rgba(0,0,0,0.52);_x000D_
  -moz-box-shadow: 0px 6px 5px -4px rgba(0,0,0,0.52);_x000D_
  box-shadow: 0px 6px 5px -4px rgba(0,0,0,0.52);                 _x000D_
/* unrelated to button styling */_x000D_
#box {_x000D_
  display: flex;_x000D_
  flex-flow: row nowrap ;_x000D_
  justify-content: center;_x000D_
  align-content: center;_x000D_
  align-items: center;_x000D_
button {_x000D_
  flex: 0 1 auto;_x000D_
  align-self: auto;_x000D_
  min-width: 0;_x000D_
  min-height: auto;_x000D_
}            _x000D_
<!DOCTYPE html>_x000D_
<html lang="en">_x000D_
    <meta charset=utf-8 />_x000D_
    <meta name="description" content="3d Button Configuration" />_x000D_
    <section id="box">_x000D_

Closing Excel Application Process in C# after Data Access

excelBook.Close(); excelApp.Quit(); add end of the code, it could be enough. it is working on my code

Android Studio does not show layout preview

Check again for SDK update because API 23: Android N (preview) is now available, download it properly OR select the API 23: Android 6.0 from the top right of the preview window. check the image

enter image description here .
It (Android Studio) automatically selects the latest one even if it not properly installed. So,

What you need to do is :

  1. install the new one properly


  2. click on the previous one.

Only Add Unique Item To List

If your requirements are to have no duplicates, you should be using a HashSet.

HashSet.Add will return false when the item already exists (if that even matters to you).

You can use the constructor that @pstrjds links to below (or here) to define the equality operator or you'll need to implement the equality methods in RemoteDevice (GetHashCode & Equals).

Changing background color of ListView items on Android

No one seemed to provide any examples of doing this solely using an adapter, so I thought I would post my code snippet for displaying ListViews where the "curSelected" item has a different background:

final ListView lv = (ListView)findViewById(;
lv.setAdapter(new BaseAdapter()
    public View getView(int position, View convertView, ViewGroup parent)
        if (convertView == null)
            convertView = new TextView(ListHighlightTestActivity.this);
            convertView.setPadding(10, 10, 10, 10);

        convertView.setBackgroundColor((position == curSelected) ? 
            Color.argb(0x80, 0x20, 0xa0, 0x40) : Color.argb(0, 0, 0, 0));

        return convertView;

    public long getItemId(int position)
        return position;

    public Object getItem(int position)
        return "item " + position;

    public int getCount()
        return 20;

This has always been a helpful approach for me for when appearance of list items needs to change dynamically.

Can't import Numpy in Python

I was trying to import numpy in python 3.2.1 on windows 7.

Followed suggestions in above answer for as below after unzipping it

cd numpy-1.6
python install

but got an error with a statement as below

unable to find vcvarsall.bat

For this error I found a related question here which suggested installing mingW. MingW was taking some time to install.

In the meanwhile tried to install numpy 1.6 again using the direct windows installer available at this link the file name is "numpy-1.6.1-win32-superpack-python3.2.exe"

Installation went smoothly and now I am able to import numpy without using mingW.

Long story short try using windows installer for numpy, if one is available.

Copy files from one directory into an existing directory

If you want to copy something from one directory into the current directory, do this:

cp dir1/* .

This assumes you're not trying to copy hidden files.

Powershell folder size of folders without listing Subdirectories

from with du.exe or du64.exe -l 1 . or 2 levels down: **du -l 2 c:**

Much shorter than Linux though ;)

Java sending and receiving file (byte[]) over sockets

Rookie, if you want to write a file to server by socket, how about using fileoutputstream instead of dataoutputstream? dataoutputstream is more fit for protocol-level read-write. it is not very reasonable for your code in bytes reading and writing. loop to read and write is necessary in java io. and also, you use a buffer way. flush is necessary. here is a code sample:

How to get ALL child controls of a Windows Forms form of a specific type (Button/Textbox)?

A clean and easy solution (C#):

static class Utilities {
    public static List<T> GetAllControls<T>(this Control container) where T : Control {
        List<T> controls = new List<T>();
        if (container.Controls.Count > 0) {
            foreach (Control c in container.Controls) {

        return controls;

Get all textboxes:

List<TextBox> textboxes = myControl.GetAllControls<TextBox>();

How do I remove background-image in css?

If your div rule is just div {...}, then #a {...} will be sufficient. If it is more complicated, you need a "more specific" selector, as defined by the CSS specification on specificity. (#a being more specific than div is just single aspect in the algorithm.)

How to pass an array within a query string?

You can use http_build_query to generate a URL-encoded querystring from an array in PHP. Whilst the resulting querystring will be expanded, you can decide on a unique separator you want as a parameter to the http_build_query method, so when it comes to decoding, you can check what separator was used. If it was the unique one you chose, then that would be the array querystring otherwise it would be the normal querystrings.

How to flush route table in windows?

In Microsoft Windows, you can go through by route -f command to delete your current Gateway, check route / ? for more advance option, like add / delete etc and also can write a batch to add route on specific time as well but if you need to delete IP cache, then you have the option to use arp command.

Random float number generation

If you are using C++ and not C, then remember that in technical report 1 (TR1) and in the C++0x draft they have added facilities for a random number generator in the header file, I believe it is identical to the Boost.Random library and definitely more flexible and "modern" than the C library function, rand.

This syntax offers the ability to choose a generator (like the mersenne twister mt19937) and then choose a distribution (normal, bernoulli, binomial etc.).

Syntax is as follows (shameless borrowed from this site):

  #include <iostream>
  #include <random>


  std::tr1::mt19937 eng;  // a core engine class 
  std::tr1::normal_distribution<float> dist;     

  for (int i = 0; i < 10; ++i)        
      std::cout << dist(eng) << std::endl;

LabelEncoder: TypeError: '>' not supported between instances of 'float' and 'str'

As string data types have variable length, it is by default stored as object type. I faced this problem after treating missing values too. Converting all those columns to type 'category' before label encoding worked in my case.


And then check df.dtypes and perform label encoding.

ERROR 1130 (HY000): Host '' is not allowed to connect to this MySQL server

Go to PhpMyAdmin, click on desired database, go to Privilages tab and create new user "remote", and give him all privilages and in host field set "Any host" option(%).

How to check if a column exists in Pandas

Just to suggest another way without using if statements, you can use the get() method for DataFrames. For performing the sum based on the question:

df['sum'] = df.get('A', df['B']) + df['C']

The DataFrame get method has similar behavior as python dictionaries.

HTML Upload MAX_FILE_SIZE does not appear to work

MAX_FILE_SIZE is in KB not bytes. You were right, it is in bytes. So, for a limit of 4MB convert 4MB in bytes {1024 * (1024 * 4)} try:

<input type="hidden" name="MAX_FILE_SIZE" value="4194304" /> 

enter image description here

Update 1

As explained by others, you will never get a warning for this. It's there just to impose a soft limit on server side.

Update 2

To answer your sub-question. Yes, there is a difference, you NEVER trust the user input. If you want to always impose a limit, you always must check its size. Don't trust what MAX_FILE_SIZE does, because it can be changed by a user. So, yes, you should check to make sure it's always up to or above the size you want it to be.

The difference is that if you have imposed a MAX_FILE_SIZE of 2MB and the user tries to upload a 4MB file, once they reach roughly the first 2MB of upload, the transfer will terminate and the PHP will stop accepting more data for that file. It will report the error on the files array.

Dependency Walker reports IESHIMS.DLL and WER.DLL missing?

1· Do I need these DLL's?

It depends since Dependency Walker is a little bit out of date and may report the wrong dependency.

  1. Where can I get them?

most dlls can be found at

I believe they are supposed to located in C:\Windows\System32\Wer.dll and C:\Program Files\Internet Explorer\Ieshims.dll

For me leshims.dll can be placed at C:\Windows\System32\. Context: windows 7 64bit.

Laravel view not found exception

If your path to view is true first try to config:cache and route:cache if nothing changed check your resource path permission are true.

example: your can do it in ubuntu with :

sudo chgrp -R www-data resources/views
sudo usermod -a -G www-data $USER

How to center a component in Material-UI and make it responsive?

Another option is:

<Grid container justify = "center">
  <Your centered component/>

Can you delete data from influxdb?

The accepted answer (DROP SERIES) will work for many cases, but will not work if the records you need to delete are distributed among many time ranges and tag sets.

A more general purpose approach (albeit a slower one) is to issue the delete queries one-by-one, with the use of another programming language.

  1. Query for all the records you need to delete (or use some filtering logic in your script)
  2. For each of the records you want to delete:

    1. Extract the time and the tag set (ignore the fields)
    2. Format this into a query, e.g.

      DELETE FROM "things" WHERE time=123123123 AND tag1='val' AND tag2='val'

      Send each of the queries one at a time

How to add a local repo and treat it as a remote repo

You have your arguments to the remote add command reversed:

git remote add <NAME> <PATH>


git remote add bak /home/sas/dev/apps/smx/repo/bak/ontologybackend/.git

See git remote --help for more information.

Selenium: WebDriverException:Chrome failed to start: crashed as google-chrome is no longer running so ChromeDriver is assuming that Chrome has crashed

i faced the same problem but i solved it by moving the chromedriver to this path '/opt/google/chrome/'

and this code works correctly

from selenium.webdriver import Chrome
driver = Chrome('/opt/google/chrome/chromedrive')

force browsers to get latest js and css files in application

Starting from the above answer I modified a little bit the code to make the helper work with CSS files too and add a version every time when you do some change in the files and not only when you do the build

public static class HtmlHelperExtensions
    public static MvcHtmlString IncludeVersionedJs(this HtmlHelper helper, string filename)
        string version = GetVersion(helper, filename);
        return MvcHtmlString.Create("<script type='text/javascript' src='" + filename + version + "'></script>");

    public static MvcHtmlString IncludeVersionedCss(this HtmlHelper helper, string filename)
        string version = GetVersion(helper, filename);
        return MvcHtmlString.Create("<link href='" + filename + version + "' type ='text/css' rel='stylesheet'/>");

    private static string GetVersion(this HtmlHelper helper, string filename)
        var context = helper.ViewContext.RequestContext.HttpContext;
        var physicalPath = context.Server.MapPath(filename);
        var version = "?v=" +
        new System.IO.FileInfo(physicalPath).LastWriteTime
        context.Cache.Add(physicalPath, version, null,
          DateTime.Now.AddMinutes(1), TimeSpan.Zero,
          CacheItemPriority.Normal, null);

        if (context.Cache[filename] == null)
            context.Cache[filename] = version;
            return version;
            if (version != context.Cache[filename].ToString())
                context.Cache[filename] = version;
                return version;
            return context.Cache[filename] as string;

How do I execute code AFTER a form has loaded?

First time it WILL NOT start "AfterLoading",
It will just register it to start NEXT Load.

private void Main_Load(object sender, System.EventArgs e)
    //Register it to Start in Load 
    //Starting from the Next time.
    this.Activated += AfterLoading;

private void AfterLoading(object sender, EventArgs e)
    this.Activated -= AfterLoading;
    //Write your code here.

What's the difference between 'r+' and 'a+' when open file in python?

If you have used them in C, then they are almost same as were in C.

From the manpage of fopen() function : -

  • r+ : - Open for reading and writing. The stream is positioned at the beginning of the file.

  • a+ : - Open for reading and writing. The file is created if it does not exist. The stream is positioned at the end of the file. Subse- quent writes to the file will always end up at the then current end of file, irrespective of any intervening fseek(3) or similar.

How to redirect a url in NGINX

This is the top hit on Google for "nginx redirect". If you got here just wanting to redirect a single location:

location = /content/unique-page-name {
  return 301 /new-name/unique-page-name;

anaconda - path environment variable in windows

You could also just re-install Anaconda, and tick the option add variable to Path.. This will prevent you from making mistakes when editing environment variables. If you make mistakes here, your operating system could start malfunctioning.

Eloquent ->first() if ->exists()

(ps - I couldn't comment) I think your best bet is something like you've done, or similar to:

$user = User::where('mobile', Input::get('mobile'));
$user->exists() and $user = $user->first();

Oh, also: count() instead if exists but this could be something used after get.

How to show and update echo on same line

Well I did not read correctly the man echo page for this.

echo had 2 options that could do this if I added a 3rd escape character.

The 2 options are -n and -e.

-n will not output the trailing newline. So that saves me from going to a new line each time I echo something.

-e will allow me to interpret backslash escape symbols.

Guess what escape symbol I want to use for this: \r. Yes, carriage return would send me back to the start and it will visually look like I am updating on the same line.

So the echo line would look like this:

echo -ne "Movie $movies - $dir ADDED!"\\r

I had to escape the escape symbol so Bash would not kill it. that is why you see 2 \ symbols in there.

As mentioned by William, printf can also do similar (and even more extensive) tasks like this.

What is the difference between 'my' and 'our' in Perl?

my is used for local variables, whereas our is used for global variables.

More reading over at Variable Scoping in Perl: the basics.

Anaconda Navigator won't launch (windows 10)

I am not sure why but the command below worked for me.

pip install pyqt5

Of course I updated Anaconda and Navigator before running this command.

An unhandled exception occurred during the execution of the current web request. ASP.NET

  1. If you are facing this problem (Enter windows + R) an delete temp(%temp%)and windows temp.
  2. Some file is not deleted that time stop IIS(Internet information service) and delete that all remaining files .

Check your problem is solved.

How to rotate x-axis tick labels in Pandas barplot

The question is clear but the title is not as precise as it could be. My answer is for those who came looking to change the axis label, as opposed to the tick labels, which is what the accepted answer is about. (The title has now been corrected).

for ax in plt.gcf().axes:
    plt.xlabel(ax.get_xlabel(), rotation=90)

Docker compose port mapping

If you want to bind to the redis port from your nodejs container you will have to expose that port in the redis container:

version: '2'
      context: .
      dockerfile: DockerFile
      - "4000:4000"
      - redis

      context: .
      dockerfile: Dockerfile-redis
      - "6379"

The expose tag will let you expose ports without publishing them to the host machine, but they will be exposed to the containers networks.

The ports tag will be mapping the host port with the container port HOST:CONTAINER

Create or update mapping in elasticsearch

In later Elasticsearch versions (7.x), types were removed. Updating a mapping can becomes:

curl -XPUT "http://localhost:9200/test/_mapping" -H 'Content-Type: application/json' -d'{
  "properties": {
    "new_geo_field": {
      "type": "geo_point"

As others have pointed out, if the field exists, you typically have to reindex. There are exceptions, such as adding a new sub-field or changing analysis settings.

You can't "create a mapping", as the mapping is created with the index. Typically, you'd define the mapping when creating the index (or via index templates):

curl -XPUT "http://localhost:9200/test" -H 'Content-Type: application/json' -d'{
  "mappings": {
    "properties": {
      "foo_field": {
        "type": "text"

That's because, in production at least, you'd want to avoid letting Elasticsearch "guess" new fields. Which is what generated this question: geo data was read as an array of long values.

Checking for a null int value from a Java ResultSet

You can call this method using the resultSet and the column name having Number type. It will either return the Integer value, or null. There will be no zeros returned for empty value in the database

private Integer getIntWithNullCheck(ResultSet rset, String columnName) {
    try {
        Integer value = rset.getInt(columnName);
        return rset.wasNull() ? null : value;
    } catch (Exception e) {
        return null;

How to get the first non-null value in Java?

How about using suppliers when you want to avoid evaluating some expensive method?

Like this:

public static <T> T coalesce(Supplier<T>... items) {
for (Supplier<T> item : items) {
    T value = item.get();
    if (value != null) {
        return value;
    return null;

And then using it like this:

Double amount = coalesce(order::firstAmount, order::secondAmount, order::thirdAmount)

You can also use overloaded methods for the calls with two, three or four arguments.

In addition, you could also use streams with something like this:

public static <T> T coalesce2(Supplier<T>... s) {

SQL Server JOIN missing NULL values

Try using additional condition in join:

SELECT Table1.Col1, Table1.Col2, Table1.Col3, Table2.Col4
FROM Table1 
ON (Table1.Col1 = Table2.Col1 
    OR (Table1.Col1 IS NULL AND Table2.Col1 IS NULL)

Maximum length of HTTP GET request

The limit is dependent on both the server and the client used (and if applicable, also the proxy the server or the client is using).

Most web servers have a limit of 8192 bytes (8 KB), which is usually configurable somewhere in the server configuration. As to the client side matter, the HTTP 1.1 specification even warns about this. Here's an extract of chapter 3.2.1:

Note: Servers ought to be cautious about depending on URI lengths above 255 bytes, because some older client or proxy implementations might not properly support these lengths.

The limit in Internet Explorer and Safari is about 2 KB, in Opera about 4 KB and in Firefox about 8 KB. We may thus assume that 8 KB is the maximum possible length and that 2 KB is a more affordable length to rely on at the server side and that 255 bytes is the safest length to assume that the entire URL will come in.

If the limit is exceeded in either the browser or the server, most will just truncate the characters outside the limit without any warning. Some servers however may send an HTTP 414 error.

If you need to send large data, then better use POST instead of GET. Its limit is much higher, but more dependent on the server used than the client. Usually up to around 2 GB is allowed by the average web server.

This is also configurable somewhere in the server settings. The average server will display a server-specific error/exception when the POST limit is exceeded, usually as an HTTP 500 error.

How to use Apple's new San Francisco font on a webpage

Apple is abstracting the system fonts going forward. This facility uses new generic family name -apple-system. So something like below should get you what you want.

  font-family: -apple-system, "Helvetica Neue", "Lucida Grande";

Printing Batch file results to a text file

For Print Result to text file

we can follow

echo "test data" > test.txt

This will create test.txt file and written "test data"

If you want to append then

echo "test data" >> test.txt

In Java, how to append a string more efficiently?

You should use the StringBuilder class.

StringBuilder stringBuilder = new StringBuilder();

stringBuilder.append("Some text");
stringBuilder.append("Some text");
stringBuilder.append("Some text");

String finalString = stringBuilder.toString();

In addition, please visit:

Cropping images in the browser BEFORE the upload

The Pixastic library does exactly what you want. However, it will only work on browsers that have canvas support. For those older browsers, you'll either need to:

  1. supply a server-side fallback, or
  2. tell the user that you're very sorry, but he'll need to get a more modern browser.

Of course, option #2 isn't very user-friendly. However, if your intent is to provide a pure client-only tool and/or you can't support a fallback back-end cropper (e.g. maybe you're writing a browser extension or offline Chrome app, or maybe you can't afford a decent hosting provider that provides image manipulation libraries), then it's probably fair to limit your user base to modern browsers.

EDIT: If you don't want to learn Pixastic, I have added a very simple cropper on jsFiddle here. It should be possible to modify and integrate and use the drawCroppedImage function with Jcrop.

Jquery each - Stop loop and return object

Because when you use a return statement inside an each loop, a "non-false" value will act as a continue, whereas false will act as a break. You will need to return false from the each function. Something like this:

function findXX(word) {
    var toReturn; 
    $.each(someArray, function(i) {
        $('body').append('-> '+i+'<br />');
        if(someArray[i] == word) {
            toReturn = someArray[i];
            return false;
    return toReturn; 

From the docs:

We can break the $.each() loop at a particular iteration by making the callback function return false. Returning non-false is the same as a continue statement in a for loop; it will skip immediately to the next iteration.

Implement specialization in ER diagram

So I assume your permissions table has a foreign key reference to admin_accounts table. If so because of referential integrity you will only be able to add permissions for account ids exsiting in the admin accounts table. Which also means that you wont be able to enter a user_account_id [assuming there are no duplicates!]

Error resolving template "index", template might not exist or might not be accessible by any of the configured Template Resolvers

It May be due to some exceptions like (Parsing NUMERIC to String or vise versa).

Please verify cell values either are null or do handle Exception and see.

Best, Shahid

CSS rotate property in IE

Usefull Link for IE transform

This tool converts CSS3 Transform properties (which almost all modern browsers use) to the equivalent CSS using Microsoft's proprietary Visual Filters technology.

How to know if two arrays have the same values

If you only want to test for primitive values, you can try:

if(JSON.stringify(arr1.sort()) !== JSON.stringify(arr2.sort())) {

Print execution time of a shell command

If I'm starting a long-running process like a copy or hash and I want to know later how long it took, I just do this:

$ date; sha1sum reallybigfile.txt; date

Which will result in the following output:

Tue Jun  2 21:16:03 PDT 2015
5089a8e475cc41b2672982f690e5221469390bc0  reallybigfile.txt
Tue Jun  2 21:33:54 PDT 2015

Granted, as implemented here it isn't very precise and doesn't calculate the elapsed time. But it's dirt simple and sometimes all you need.

Use '=' or LIKE to compare strings in SQL?

LIKE and the equality operator have different purposes, they don't do the same thing:
= is much faster, whereas LIKE can interpret wildcards. Use = wherever you can and LIKE wherever you must.

SELECT * FROM user WHERE login LIKE 'Test%';

Sample matches:


Difference between numeric, float and decimal in SQL Server

They Differ in Data Type Precedence

Decimal and Numeric are the same functionally but there is still data type precedence, which can be crucial in some cases.


The resulting data type is numeric because it takes data type precedence.

Exhaustive list of data types by precedence:

Reference link

What is a raw type and why shouldn't we use it?

I found this page after doing some sample exercises and having the exact same puzzlement.

============== I went from this code as provide by the sample ===============

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

    Map wordMap = new HashMap();
    if (args.length > 0) {
        for (int i = 0; i < args.length; i++) {
            countWord(wordMap, args[i]);
    } else {
        getWordFrequency(, wordMap);
    for (Iterator i = wordMap.entrySet().iterator(); i.hasNext();) {
        Map.Entry entry = (Map.Entry);
        System.out.println(entry.getKey() + " :\t" + entry.getValue());

====================== To This code ========================

public static void main(String[] args) throws IOException {
    // replace with TreeMap to get them sorted by name
    Map<String, Integer> wordMap = new HashMap<String, Integer>();
    if (args.length > 0) {
        for (int i = 0; i < args.length; i++) {
            countWord(wordMap, args[i]);
    } else {
        getWordFrequency(, wordMap);
    for (Iterator<Entry<String, Integer>> i = wordMap.entrySet().iterator(); i.hasNext();) {
        Entry<String, Integer> entry =;
        System.out.println(entry.getKey() + " :\t" + entry.getValue());



It may be safer but took 4 hours to demuddle the philosophy...

How do I "Add Existing Item" an entire directory structure in Visual Studio?

Drag the files / folders from Windows Explorer into the Solution Explorer. It will add them all. Note this doesn't work if Visual Studio is in Administrator Mode, because Windows Explorer is a User Mode process.

How can I select all children of an element except the last child?

There is a:not selector in css3. Use :not() with :last-child inside to select all children except last one. For example, to select all li in ul except last li, use following code.

ul li:not(:last-child){   }

jQuery - Getting form values for ajax POST

var username = $('#username').val();
var email= $('#email').val();
var password= $('#password').val();

Regular Expression to reformat a US phone number in Javascript

Almost all of these have issues when the user tries to backspace over the delimiters, particularly from the middle of the string.

Here's a jquery solution that handles that, and also makes sure the cursor stays in the right place as you edit:

//format text input as phone number (nnn) nnn-nnnn
$('.myPhoneField').on('input', function (e){
    var $phoneField =;
    var cursorPosition = $phoneField.selectionStart;
    var numericString = $phoneField.value.replace(/\D/g, '').substring(0, 10);

    // let user backspace over the '-'
    if (cursorPosition === 9 && numericString.length > 6) return;

    // let user backspace over the ') '
    if (cursorPosition === 5 && numericString.length > 3) return;
    if (cursorPosition === 4 && numericString.length > 3) return;

    var match = numericString.match(/^(\d{1,3})(\d{0,3})(\d{0,4})$/);
    if (match) {
        var newVal = '(' + match[1];
        newVal += match[2] ? ') ' + match[2] : '';
        newVal += match[3] ? '-' + match[3] : '';

        // to help us put the cursor back in the right place
        var delta = newVal.length - Math.min($phoneField.value.length, 14);      
        $phoneField.value = newVal;
        $phoneField.selectionEnd = cursorPosition + delta;
    } else {
        $phoneField.value = '';        

JSON.stringify output to div in pretty print way

Full disclosure I am the author of this package but another way to output JSON or JavaScript objects in a readable way complete with being able skip parts, collapse them, etc. is nodedump,

Plugin is too old, please update to a more recent version, or set ANDROID_DAILY_OVERRIDE environment variable to

This issue occurs because of the Gradle version changes, since your application uses old version of gradle, you need to update to new version.

This changes needs to be done in build.gradle file, have look at this link to know how to update the gradle and detailed steps are provided. there.


Plot a bar using matplotlib using a dictionary

The best way to implement it using, height, tick_label) where the range provides scalar values for the positioning of the corresponding bar in the graph. tick_label does the same work as xticks(). One can replace it with an integer also and use multiple, height, tick_label). For detailed information please refer the documentation.

import matplotlib.pyplot as plt

data = {'apple': 67, 'mango': 60, 'lichi': 58}
names = list(data.keys())
values = list(data.values())

#tick_label does the some work as plt.xticks(),values,tick_label=names)

enter image description here

Additionally the same plot can be generated without using range(). But the problem encountered was that tick_label just worked for the last call. Hence xticks() was used for labelling:

data = {'apple': 67, 'mango': 60, 'lichi': 58}
names = list(data.keys())
values = list(data.values()),values[0],tick_label=names[0]),values[1],tick_label=names[1]),values[2],tick_label=names[2])

enter image description here

Create excel ranges using column numbers in vba?

I really like stackPusher's ConvertToLetter function as a solution. However, in working with it I noticed several errors occurring at very specific inputs due to some flaws in the math. For example, inputting 392 returns 'N\', 418 returns 'O\', 444 returns 'P\', etc.

I reworked the function and the result produces the correct output for all input up to 703 (which is the first triple-letter column index, AAA).

Function ConvertToLetter2(iCol As Integer) As String
    Dim First As Integer
    Dim Second As Integer
    Dim FirstChar As String
    Dim SecondChar As String

    First = Int(iCol / 26)
    If First = iCol / 26 Then
        First = First - 1
    End If
    If First = 0 Then
        FirstChar = ""
        FirstChar = Chr(First + 64)
    End If

    Second = iCol Mod 26
    If Second = 0 Then
        SecondChar = Chr(26 + 64)
        SecondChar = Chr(Second + 64)
    End If

    ConvertToLetter2 = FirstChar & SecondChar

End Function

Format price in the current locale and currency

try this:

<?php echo Mage::app()->getLocale()->currency(Mage::app()->getStore()->getCurrentCurrencyCode())->getSymbol(); ?>

Multiple separate IF conditions in SQL Server

To avoid syntax errors, be sure to always put BEGIN and END after an IF clause, eg:

IF (@A!= @SA)
   --do stuff
IF (@C!= @SC)
   --do stuff

... and so on. This should work as expected. Imagine BEGIN and END keyword as the opening and closing bracket, respectively.

How to set gradle home while importing existing project in Android studio

I am using Lubuntu, I ended up finding it in :


File Upload ASP.NET MVC 3.0

How i do mine is pretty much as above ill show you my code and how to use it with a MYSSQL DB...

Document table in DB -

int Id ( PK ), string Url, string Description, CreatedBy, TenancyId DateUploaded

The above code ID, being the Primary key, URL being the name of the file ( with file type on the end ), file description to ouput on documents view, CreatedBy being who uploaded the file, tenancyId, dateUploaded

inside the view you must define the enctype or it will not work correctly.

@using (Html.BeginForm("Upload", "Document", FormMethod.Post, new { enctype = "multipart/form-data" }))
<div class="input-group">
    <label for="file">Upload a document:</label>
    <input type="file" name="file" id="file" />

The above code will give you the browse button, then inside my project I have a class basically called IsValidImage which just checks the filesize is under your specified max size, checks if its an IMG file, this is all in a class bool function. So if true returns true.

public static bool IsValidImage(HttpPostedFileBase file, double maxFileSize, ModelState ms )
    // make sur the file isnt null.
    if( file == null )
        return false;

// the param I normally set maxFileSize is 10MB  10 * 1024 * 1024 = 10485760 bytes converted is 10mb
var max = maxFileSize * 1024 * 1024;

// check if the filesize is above our defined MAX size.
if( file.ContentLength > max )
    return false;

    // define our allowed image formats
    var allowedFormats = new[] { ImageFormat.Jpeg, ImageFormat.Png, ImageFormat.Gif, ImageFormat.Bmp };

    // Creates an Image from the specified data stream.      
    using (var img = Image.FromStream(file.InputStream))
        // Return true if the image format is allowed
        return allowedFormats.Contains(img.RawFormat);
catch( Exception ex )
    ms.AddModelError( "", ex.Message );                 
return false;   

So in the controller:

if (!Code.Picture.IsValidUpload(model.File, 10, true))
    return View(model);

// Set the file name up... Being random guid, and then todays time in ticks. Then add the file extension
// to the end of the file name
var dbPath = Guid.NewGuid().ToString() + DateTime.UtcNow.Ticks + Path.GetExtension(model.File.FileName);

// Combine the two paths together being the location on the server to store it
// then the actual file name and extension.
var path = Path.Combine(Server.MapPath("~/Uploads/Documents/"), dbPath);

// set variable as Parent directory I do this to make sure the path exists if not
// I will create the directory.
var directoryInfo = new FileInfo(path).Directory;

if (directoryInfo != null)

// save the document in the combined path.

// then add the data to the database
_db.Documents.Add(new Document
    TenancyId = model.SelectedTenancy,
    FileUrl = dbPath,
    FileDescription = model.Description,
    CreatedBy = loggedInAs,
    CreatedDate = DateTime.UtcNow,
    UpdatedDate = null,
    CanTenantView = true

model.Successfull = true;

How can I get useful error messages in PHP?

If the error is in PHP code, you can use error_reporting() function within your code to set to the report all.

However, this does not handle the situation when PHP crashes. Information about that is only available in server logs. Maybe you don't have access to those, but many hosting providers I've worked with have some way to let you access it. For example, the approach I like best is that it creates the error_log file in the current directory where .php resides. Try searching there or contact your hosting provider about this.

Writing a pandas DataFrame to CSV file

When you are storing a DataFrame object into a csv file using the to_csv method, you probably wont be needing to store the preceding indices of each row of the DataFrame object.

You can avoid that by passing a False boolean value to index parameter.

Somewhat like:

df.to_csv(file_name, encoding='utf-8', index=False)

So if your DataFrame object is something like:

  Color  Number
0   red     22
1  blue     10

The csv file will store:


instead of (the case when the default value True was passed)


Difference between application/x-javascript and text/javascript content types

mime-types starting with x- are not standardized. In case of javascript it's kind of outdated. Additional the second code snippet

<?Header('Content-Type: text/javascript');?>

requires short_open_tags to be enabled. you should avoid it.

<?php Header('Content-Type: text/javascript');?>

However, the completely correct mime-type for javascript is


Getting time elapsed in Objective-C

For percise time measurements (like GetTickCount), also take a look at mach_absolute_time and this Apple Q&A:

Extract Data from PDF and Add to Worksheet

I know this is an old issue but I just had to do this for a project at work, and I am very surprised that nobody has thought of this solution yet: Just open the .pdf with Microsoft word.

The code is a lot easier to work with when you are trying to extract data from a .docx because it opens in Microsoft Word. Excel and Word play well together because they are both Microsoft programs. In my case, the file of question had to be a .pdf file. Here's the solution I came up with:

  1. Choose the default program to open .pdf files to be Microsoft Word
  2. The first time you open a .pdf file with word, a dialogue box pops up claiming word will need to convert the .pdf into a .docx file. Click the check box in the bottom left stating "do not show this message again" and then click OK.
  3. Create a macro that extracts data from a .docx file. I used MikeD's Code as a resource for this.
  4. Tinker around with the MoveDown, MoveRight, and Find.Execute methods to fit the need of your task.

Yes you could just convert the .pdf file to a .docx file but this is a much simpler solution in my opinion.

Generate random string/characters in JavaScript

This is for firefox chrome code (addons and the like)

It can save you a few hours of research.

function randomBytes( amount )
    let bytes = Cc[ ';1' ]

        .getService         ( Ci.nsIRandomGenerator )
        .generateRandomBytes( amount, ''            )

    return bytes.reduce( bytes2Number )

    function bytes2Number( previousValue, currentValue, index, array )
      return Math.pow( 256, index ) * currentValue + previousValue

Use it as:

let   strlen   = 5
    , radix    = 36
    , filename = randomBytes( strlen ).toString( radix ).splice( - strlen )

Decimal values in SQL for dividing results

just convert denominator to decimal before division e.g

select col1 / CONVERT(decimal(4,2), col2) from tbl1

Android runOnUiThread explanation

This should work for you

 public class MyActivity extends Activity {

    protected ProgressDialog mProgressDialog;
    /** Called when the activity is first created. */
    public void onCreate(Bundle savedInstanceState) {

    private void populateTable() {
        mProgressDialog =, "Please wait","Long operation starts...", true);
        new Thread() {
            public void run() {

                try {

                    // code runs in a thread
                    runOnUiThread(new Runnable() {
                        public void run() {
                } catch (final Exception ex) {
                    Log.i("---","Exception in thread");


    /** fake operation for testing purpose */
    protected void doLongOperation() {
        try {
        } catch (InterruptedException e) {


WPF - add static items to a combo box

Like this:

<ComboBox Text="MyCombo">
<ComboBoxItem  Name="cbi1">Item1</ComboBoxItem>
<ComboBoxItem  Name="cbi2">Item2</ComboBoxItem>
<ComboBoxItem  Name="cbi3">Item3</ComboBoxItem>

How do I convert hh:mm:ss.000 to milliseconds in Excel?

try this:


Maybe you need to change semi-colon by coma...

MySQL vs MongoDB 1000 reads

Here is a little research that explored RDBMS vs NoSQL using MySQL vs Mongo, the conclusions were inline with @Sean Reilly's response. In short, the benefit comes from the design, not some raw speed difference. Conclusion on page 35-36:

RDBMS vs NoSQL: Performance and Scaling Comparison

The project tested, analysed and compared the performance and scalability of the two database types. The experiments done included running different numbers and types of queries, some more complex than others, in order to analyse how the databases scaled with increased load. The most important factor in this case was the query type used as MongoDB could handle more complex queries faster due mainly to its simpler schema at the sacrifice of data duplication meaning that a NoSQL database may contain large amounts of data duplicates. Although a schema directly migrated from the RDBMS could be used this would eliminate the advantage of MongoDB’s underlying data representation of subdocuments which allowed the use of less queries towards the database as tables were combined. Despite the performance gain which MongoDB had over MySQL in these complex queries, when the benchmark modelled the MySQL query similarly to the MongoDB complex query by using nested SELECTs MySQL performed best although at higher numbers of connections the two behaved similarly. The last type of query benchmarked which was the complex query containing two JOINS and and a subquery showed the advantage MongoDB has over MySQL due to its use of subdocuments. This advantage comes at the cost of data duplication which causes an increase in the database size. If such queries are typical in an application then it is important to consider NoSQL databases as alternatives while taking in account the cost in storage and memory size resulting from the larger database size.

no match for ‘operator<<’ in ‘std::operator

Obviously, the standard library provided operator does not know what to do with your user defined type mystruct. It only works for predefined data types. To be able to use it for your own data type, You need to overload operator << to take your user defined data type.

Play/pause HTML 5 video using JQuery

<video style="min-width: 100%; min-height: 100%; " id="vid" width="auto" height="auto" controls autoplay="true" loop="loop" preload="auto" muted="muted">
<source src="video/sample.mp4" type="video/mp4">
<source src="video/sample.ogg" type="video/ogg">
document.getElementById('vid').play(); });

Get value from SimpleXMLElement Object

If you know that the value of the XML element is a float number (latitude, longitude, distance), you can use (float)

$value = (float) $xml->code[0]->lat;

Also, (int) for integer number:

$value = (int) $xml->code[0]->distance;

Remove tracking branches no longer on remote

git remote prune origin prunes tracking branches not on the remote.

git branch --merged lists branches that have been merged into the current branch.

xargs git branch -d deletes branches listed on standard input.

Be careful deleting branches listed by git branch --merged. The list could include master or other branches you'd prefer not to delete.

To give yourself the opportunity to edit the list before deleting branches, you could do the following in one line:

git branch --merged >/tmp/merged-branches && \
  vi /tmp/merged-branches && xargs git branch -d </tmp/merged-branches

How to permanently add a private key with ssh-add on Ubuntu?

This worked for me.

ssh-agent /bin/sh
ssh-add /path/to/your/key

Catching an exception while using a Python 'with' statement

The best "Pythonic" way to do this, exploiting the with statement, is listed as Example #6 in PEP 343, which gives the background of the statement.

def opened_w_error(filename, mode="r"):
        f = open(filename, mode)
    except IOError, err:
        yield None, err
            yield f, None

Used as follows:

with opened_w_error("/etc/passwd", "a") as (f, err):
    if err:
        print "IOError:", err

Using Linq to group a list of objects into a new grouped list of list of objects

var groupedCustomerList = userList
    .GroupBy(u => u.GroupID)
    .Select(grp => grp.ToList())

jQuery - checkbox enable/disable

<form name="frmChkForm" id="frmChkForm">
<input type="checkbox" name="chkcc9" id="chkAll">Check Me
<input type="checkbox" name="chk9[120]" class="chkGroup">
<input type="checkbox" name="chk9[140]" class="chkGroup">
<input type="checkbox" name="chk9[150]" class="chkGroup">

$("#chkAll").click(function() {
   $(".chkGroup").attr("checked", this.checked);

With added functionality to ensure the check all checkbox gets checked/dechecked if all individual checkboxes are checked:

$(".chkGroup").click(function() {
  $("#chkAll")[0].checked = $(".chkGroup:checked").length == $(".chkGroup").length;

App.Config file in console application C#

use this


Removing nan values from an array

Doing the above :

x = x[~numpy.isnan(x)]


x = x[numpy.logical_not(numpy.isnan(x))]

I found that resetting to the same variable (x) did not remove the actual nan values and had to use a different variable. Setting it to a different variable removed the nans. e.g.

y = x[~numpy.isnan(x)]

Certificate has either expired or has been revoked

For those who cannot find "view details" button at Account > Team > View Details, here is how I solved this on Xcode 10:

  1. Delete all provisioning profiles at ~/Library/MobileDevice/Provisioning\ Profiles/
  2. Clean the project by holding Shift(?)+Command(?)+K or selecting Product > Clean (it might be labelled "Clean Build Folder")
  3. Restart Xcode

and try again.

Calling a JavaScript function named in a variable

I'd avoid eval.

To solve this problem, you should know these things about JavaScript.

  1. Functions are first-class objects, so they can be properties of an object (in which case they are called methods) or even elements of arrays.
  2. If you aren't choosing the object a function belongs to, it belongs to the global scope. In the browser, that means you're hanging it on the object named "window," which is where globals live.
  3. Arrays and objects are intimately related. (Rumor is they might even be the result of incest!) You can often substitute using a dot . rather than square brackets [], or vice versa.

Your problem is a result of considering the dot manner of reference rather than the square bracket manner.

So, why not something like,


That's assuming your function lives in the global space. If you've namespaced, then:


Avoid eval, and avoid passing a string in to setTimeout and setInterval. I write a lot of JS, and I NEVER need eval. "Needing" eval comes from not knowing the language deeply enough. You need to learn about scoping, context, and syntax. If you're ever stuck with an eval, just ask--you'll learn quickly.

Conditional statement in a one line lambda function in python?

The right way to do this is simple:

def rate(T):
    if (T > 200):
        return 200*exp(-T)
        return 400*exp(-T)

There is absolutely no advantage to using lambda here. The only thing lambda is good for is allowing you to create anonymous functions and use them in an expression (as opposed to a statement). If you immediately assign the lambda to a variable, it's no longer anonymous, and it's used in a statement, so you're just making your code less readable for no reason.

The rate function defined this way can be stored in an array, passed around, called, etc. in exactly the same way a lambda function could. It'll be exactly the same (except a bit easier to debug, introspect, etc.).

From a comment:

Well the function needed to fit in one line, which i didn't think you could do with a named function?

I can't imagine any good reason why the function would ever need to fit in one line. But sure, you can do that with a named function. Try this in your interpreter:

>>> def foo(x): return x + 1

Also these functions are stored as strings which are then evaluated using "eval" which i wasn't sure how to do with regular functions.

Again, while it's hard to be 100% sure without any clue as to why why you're doing this, I'm at least 99% sure that you have no reason or a bad reason for this. Almost any time you think you want to pass Python functions around as strings and call eval so you can use them, you actually just want to pass Python functions around as functions and use them as functions.

But on the off chance that this really is what you need here: Just use exec instead of eval.

You didn't mention which version of Python you're using. In 3.x, the exec function has the exact same signature as the eval function:

exec(my_function_string, my_globals, my_locals)

In 2.7, exec is a statement, not a function—but you can still write it in the same syntax as in 3.x (as long as you don't try to assign the return value to anything) and it works.

In earlier 2.x (before 2.6, I think?) you have to do it like this instead:

exec my_function_string in my_globals, my_locals

How to create a static library with g++?

Create a .o file:

g++ -c header.cpp

add this file to a library, creating library if necessary:

ar rvs header.a header.o

use library:

g++ main.cpp header.a

Removing NA in dplyr pipe

I don't think desc takes an na.rm argument... I'm actually surprised it doesn't throw an error when you give it one. If you just want to remove NAs, use na.omit (base) or tidyr::drop_na:

outcome.df %>%
  na.omit() %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%

outcome.df %>%
  drop_na() %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%

If you only want to remove NAs from the HeartAttackDeath column, filter with, or use tidyr::drop_na:

outcome.df %>%
  filter(! %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%

outcome.df %>%
  drop_na(HeartAttackDeath) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%

As pointed out at the dupe, complete.cases can also be used, but it's a bit trickier to put in a chain because it takes a data frame as an argument but returns an index vector. So you could use it like this:

outcome.df %>%
  filter(complete.cases(.)) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%

plot different color for different categorical levels using matplotlib

Here's a succinct and generic solution to use a seaborn color palette.

First find a color palette you like and optionally visualize it:

sns.palplot(sns.color_palette("Set2", 8))

Then you can use it with matplotlib doing this:

# Unique category labels: 'D', 'F', 'G', ...
color_labels = df['color'].unique()

# List of RGB triplets
rgb_values = sns.color_palette("Set2", 8)

# Map label to RGB
color_map = dict(zip(color_labels, rgb_values))

# Finally use the mapped values
plt.scatter(df['carat'], df['price'], c=df['color'].map(color_map))

How can I make a float top with CSS?

Hugogi Raudel has came up with an interesting way to to achieve this by CSS. suppose here is our HTML markup:


You can achieve a 3-row column using this CSS code:

  margin: 120px 0 0 -110px;

li:nth-child(3n+3) {
  margin: 230px 0 0 -110px;

And here is the end result:
enter image description here
What we are doing here is adding a appropriate margin for each item in the row. This approach limitation is that you have to determine the column row count. it's not going to be dynamic. I'm sure it has use cases so I included this solution here.

Getting "type or namespace name could not be found" but everything seems ok?

In my case I went into the solution properties and made sure "Build" was checked in the Configuration for both projects. My main project didn't have it checked.

enter image description here

Python: Assign Value if None Exists

Here is the easiest way I use, hope works for you,

var1 = var1 or 4

This assigns 4 to var1 only if var1 is None , False or 0

Display calendar to pick a date in java

Another easy method in Netbeans is also avaiable here, There are libraries inside Netbeans itself,where the solutions for this type of situations are available.Select the relevant one as well.It is much easier.After doing the prescribed steps in the link,please restart Netbeans.

Step1:- Select Tools->Palette->Swing/AWT Components
Step2:- Click 'Add from JAR'in Palette Manager
Step3:- Browse to [NETBEANS HOME]\ide\modules\ext and select swingx-0.9.5.jar
Step4:- This will bring up a list of all the components available for the palette.  Lots of goodies here!  Select JXDatePicker.
Step5:- Select Swing Controls & click finish
Step6:- Restart NetBeans IDE and see the magic :)

How to send a html email with the bash command "sendmail"?

It's simpler to use, the -a option :

cat ~/campaigns/release-status.html | mail -s "Release Status [Green]" -a "Content-Type: text/html" [email protected]

How to pass an array into a function, and return the results with an array


$waffles = foo($waffles);

Or pass the array by reference, like suggested in the other answers.

In addition, you can add new elements to an array without writing the index, e.g.

$waffles = array(1,2,3); // filling on initialization


$waffles = array();
$waffles[] = 1;
$waffles[] = 2;
$waffles[] = 3;

On a sidenote, if you want to sum all values in an array, use array_sum()

CodeIgniter Active Record - Get number of returned rows

function getCount(){
    return $this->db->get('table_name')->num_rows();

Writing html form data to a txt file without the use of a webserver

You can use JavaScript:

<script type ="text/javascript">
 function WriteToFile(passForm) {

    set fso = CreateObject("Scripting.FileSystemObject");  
    set s = fso.CreateTextFile("C:\test.txt", True);

If this does not work, an alternative is the ActiveX object:

<script type = "text/javascript">
function WriteToFile(passForm)
var fso = new ActiveXObject("Scripting.FileSystemObject");
var s = fso.CreateTextFile("C:\\Test.txt", true);

Unfortunately, the ActiveX object, to my knowledge, is only supported in IE.

Android: Create spinner programmatically from array

ArrayAdapter<String> should work.


Spinner spinner = new Spinner(this);
ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>
            (this, android.R.layout.simple_spinner_item,
           spinnerArray); //selected item will look like a spinner set from XML

Excel select a value from a cell having row number calculated

You could use the INDIRECT function. This takes a string and converts it into a range

More info here


But it's preferable to use INDEX as it is less volatile.


This returns a value or the reference to a value from within a table or range

More info here

Put either function into cell B2 and fill down.

http://localhost:8080/ Access Error: 404 -- Not Found Cannot locate document: /

A tip for others: if you have NI applications installed, the NI Application Web Server also uses the port 8080.

Access Database opens as read only

alos check the level of access to the shared drive. if the access to the shared drive is read only the file will open in read only format.

Why does git perform fast-forward merges by default?

Let me expand a bit on a VonC's very comprehensive answer:

First, if I remember it correctly, the fact that Git by default doesn't create merge commits in the fast-forward case has come from considering single-branch "equal repositories", where mutual pull is used to sync those two repositories (a workflow you can find as first example in most user's documentation, including "The Git User's Manual" and "Version Control by Example"). In this case you don't use pull to merge fully realized branch, you use it to keep up with other work. You don't want to have ephemeral and unimportant fact when you happen to do a sync saved and stored in repository, saved for the future.

Note that usefulness of feature branches and of having multiple branches in single repository came only later, with more widespread usage of VCS with good merging support, and with trying various merge-based workflows. That is why for example Mercurial originally supported only one branch per repository (plus anonymous tips for tracking remote branches), as seen in older revisions of "Mercurial: The Definitive Guide".

Second, when following best practices of using feature branches, namely that feature branches should all start from stable version (usually from last release), to be able to cherry-pick and select which features to include by selecting which feature branches to merge, you are usually not in fast-forward situation... which makes this issue moot. You need to worry about creating a true merge and not fast-forward when merging a very first branch (assuming that you don't put single-commit changes directly on 'master'); all other later merges are of course in non fast-forward situation.


How to use .htaccess in WAMP Server?

Click on Wamp icon and open Apache/httpd.conf and search "#LoadModule rewrite_module modules/". Remove # as below and save it

LoadModule rewrite_module modules/

and restart all service.

Webpack - webpack-dev-server: command not found

I had the same issue but the below steps helped me to get out of it.

  1. Installing the 'webpack-dev-server' locally (In the project directory as it was not picking from the global installation)

    npm install --save webpack-dev-server

Can verify whether 'webpack-dev-server' folder exists inside node_modules.

  1. Running using npx for running directly

npx webpack-dev-server --mode development --config ./

npm run start also works fine where your entry in package.json scripts should be like the above like without npx.

LINK : fatal error LNK1561: entry point must be defined ERROR IN VC++

I've had this happen on VS after I changed the file's line endings. Changing them back to Windows CR LF fixed the issue.

Can scrapy be used to scrape dynamic content from websites that are using AJAX?

Another solution would be to implement a download handler or download handler middleware. (see scrapy docs for more information on downloader middleware) The following is an example class using selenium with headless phantomjs webdriver:

1) Define class within the script.

from selenium import webdriver
from scrapy.http import HtmlResponse

class JsDownload(object):

    def process_request(self, request, spider):
        driver = webdriver.PhantomJS(executable_path='D:\phantomjs.exe')
        return HtmlResponse(request.url, encoding='utf-8', body=driver.page_source.encode('utf-8'))

2) Add JsDownload() class to variable DOWNLOADER_MIDDLEWARE within

DOWNLOADER_MIDDLEWARES = {'MyProj.middleware.MiddleWareModule.MiddleWareClass': 500}

3) Integrate the HTMLResponse within Decoding the response body will get you the desired output.

class Spider(CrawlSpider):
    # define unique name of spider
    name = "spider"

    start_urls = [""] 

    def parse(self, response):
        # initialize items
        item = CrawlerItem()

        # store data as items
        item["js_enabled"] = response.body.decode("utf-8") 

Optional Addon:
I wanted the ability to tell different spiders which middleware to use so I implemented this wrapper:

def check_spider_middleware(method):
def wrapper(self, request, spider):
    msg = '%%s %s middleware step' % (self.__class__.__name__,)
    if self.__class__ in spider.middleware:
        spider.log(msg % 'executing', level=log.DEBUG)
        return method(self, request, spider)
        spider.log(msg % 'skipping', level=log.DEBUG)
        return None

return wrapper

for wrapper to work all spiders must have at minimum:

middleware = set([])

to include a middleware:

middleware = set([MyProj.middleware.ModuleName.ClassName])

The main advantage to implementing it this way rather than in the spider is that you only end up making one request. In A T's solution for example: The download handler processes the request and then hands off the response to the spider. The spider then makes a brand new request in it's parse_page function -- That's two requests for the same content.

Safe width in pixels for printing web pages?

I doubt there is one... It depends on browser, on printer (physical max dpi) and its driver, on paper size as you point out (and I might want to print on B5 paper too...), on settings (landscape or portrait?), plus you often can change the scale (percentage), etc.
Let the users tweak their settings...

Oracle 10g: Extract data (select) from XML (CLOB Type)

In case the XML store in the CLOB field in the database table. E.g for this XML:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

This is the Extract Query:

    xmltype (T.CLOB_COLUMN_NAME),
    AS Customs_office_code

Convert to Datetime MM/dd/yyyy HH:mm:ss in Sql Server

Declare @month as char(2)
Declare @date as char(2)
Declare @year as char(4)
declare @time as char(8)
declare @customdate as varchar(20)

set @month = MONTH(GetDate());
set @date = Day(GetDate());
set @year = year(GetDate());

set @customdate= @month+'/'+@date+'/'+@year+' '+ CONVERT(varchar(8), GETDATE(),108);

Django Forms: if not valid, show form with error message

@AamirAdnan's answer missing field.label; the other way to show the errors in few lines.

{% if form.errors %}
    <!-- Error messaging -->
    <div id="errors">
        <div class="inner">
            <p>There were some errors in the information you entered. Please correct the following:</p>
                {% for field in form %}
                    {% if field.errors %}<li>{{ field.label }}: {{ field.errors|striptags }}</li>{% endif %}
                {% endfor %}
    <!-- /Error messaging -->
{% endif %}

"OverflowError: Python int too large to convert to C long" on windows but not mac

Could anyone help explain why

In Python 2 a python "int" was equivalent to a C long. In Python 3 an "int" is an arbitrary precision type but numpy still uses "int" it to represent the C type "long" when creating arrays.

The size of a C long is platform dependent. On windows it is always 32-bit. On unix-like systems it is normally 32 bit on 32 bit systems and 64 bit on 64 bit systems.

or give a solution for the code on windows? Thanks so much!

Choose a data type whose size is not platform dependent. You can find the list at the most sensible choice would probably be np.int64

Checking for #N/A in Excel cell from VBA code

First check for an error (N/A value) and then try the comparisation against cvErr(). You are comparing two different things, a value and an error. This may work, but not always. Simply casting the expression to an error may result in similar problems because it is not a real error only the value of an error which depends on the expression.

If IsError(ActiveWorkbook.Sheets("Publish").Range("G4").offset(offsetCount, 0).Value) Then
  If (ActiveWorkbook.Sheets("Publish").Range("G4").offset(offsetCount, 0).Value <> CVErr(xlErrNA)) Then
    'do something
  End If
End If

How to add text to a WPF Label in code?

I believe you want to set the Content property. This has more information on what is available to a label.

Content Type text/xml; charset=utf-8 was not supported by service

For anyone who lands here by searching:

content type 'application/json; charset=utf-8' was not the expected type 'text/xml; charset=utf-8

or some subset of that error:

A similar error was caused in my case by building and running a service without proper attributes. I got this error message when I tried to update the service reference in my client application. It was resolved when I correctly applied [DataContract] and [DataMember] attributes to my custom classes.

This would most likely be applicable if your service was set up and working and then it broke after you edited it.

What is the maximum number of characters that nvarchar(MAX) will hold?

Max. capacity is 2 gigabytes of space - so you're looking at just over 1 billion 2-byte characters that will fit into a NVARCHAR(MAX) field.

Using the other answer's more detailed numbers, you should be able to store

(2 ^ 31 - 1 - 2) / 2 = 1'073'741'822 double-byte characters

1 billion, 73 million, 741 thousand and 822 characters to be precise

in your NVARCHAR(MAX) column (unfortunately, that last half character is wasted...)

Update: as @MartinMulder pointed out: any variable length character column also has a 2 byte overhead for storing the actual length - so I needed to subtract two more bytes from the 2 ^ 31 - 1 length I had previously stipulated - thus you can store 1 Unicode character less than I had claimed before.

Why is vertical-align:text-top; not working in CSS

You can use contextual selectors and move the vertical-align there. This would work with the p tag, then. Take this snippet below as an example. Any p tags within your class will respect the vertical-align control:

#header_selecttxt {
    font-family: Arial;
    font-size: 12px;
    font-weight: bold;

#header_selecttxt p {
    vertical-align: text-top;

You could also keep the vertical-align in both sections so that other, inline elements would use this.

What precisely does 'Run as administrator' do?

Things like "elevates the privileges", "restricted access token", "Administrator privilege" ... what the heck is administrator privilege anyway? are nonsense.

Here is an ACCESS_TOKEN for a process normally run from a user belonging to Administrators group.

0: kd> !process 0 1 test.exe
PROCESS 87065030  SessionId: 1  Cid: 0d60    Peb: 7ffdf000  ParentCid: 0618
    DirBase: 2f22e1e0  ObjectTable: a0c8a088  HandleCount:   6.
    Image: test.exe
    VadRoot 8720ef50 Vads 18 Clone 0 Private 83. Modified 0. Locked 0.
    DeviceMap 8936e560
    Token                             935c98e0
0: kd> !token -n 935c98e0
_TOKEN 935c98e0
TS Session ID: 0x1
User: S-1-5-21-2452432034-249115698-1235866470-1000 (no name mapped)
User Groups: 
 00 S-1-5-21-2452432034-249115698-1235866470-513 (no name mapped)
    Attributes - Mandatory Default Enabled 
 01 S-1-1-0 (Well Known Group: localhost\Everyone)
    Attributes - Mandatory Default Enabled 
 02 S-1-5-32-544 (Alias: BUILTIN\Administrators)
    Attributes - Mandatory Default Enabled Owner 
 03 S-1-5-32-545 (Alias: BUILTIN\Users)
    Attributes - Mandatory Default Enabled 
 04 S-1-5-4 (Well Known Group: NT AUTHORITY\INTERACTIVE)
    Attributes - Mandatory Default Enabled 
 05 S-1-2-1 (Well Known Group: localhost\CONSOLE LOGON)
    Attributes - Mandatory Default Enabled 
 06 S-1-5-11 (Well Known Group: NT AUTHORITY\Authenticated Users)
    Attributes - Mandatory Default Enabled 
 07 S-1-5-15 (Well Known Group: NT AUTHORITY\This Organization)
    Attributes - Mandatory Default Enabled 
 08 S-1-5-5-0-85516 (no name mapped)
    Attributes - Mandatory Default Enabled LogonId 
 09 S-1-2-0 (Well Known Group: localhost\LOCAL)
    Attributes - Mandatory Default Enabled 
 10 S-1-5-64-10 (Well Known Group: NT AUTHORITY\NTLM Authentication)
    Attributes - Mandatory Default Enabled 
 11 S-1-16-12288 (Label: Mandatory Label\High Mandatory Level)
    Attributes - GroupIntegrity GroupIntegrityEnabled 
Primary Group: S-1-5-21-2452432034-249115698-1235866470-513 (no name mapped)
 05 0x000000005 SeIncreaseQuotaPrivilege          Attributes - 
 08 0x000000008 SeSecurityPrivilege               Attributes - 
 09 0x000000009 SeTakeOwnershipPrivilege          Attributes - 
 10 0x00000000a SeLoadDriverPrivilege             Attributes - 
 11 0x00000000b SeSystemProfilePrivilege          Attributes - 
 12 0x00000000c SeSystemtimePrivilege             Attributes - 
 13 0x00000000d SeProfileSingleProcessPrivilege   Attributes - 
 14 0x00000000e SeIncreaseBasePriorityPrivilege   Attributes - 
 15 0x00000000f SeCreatePagefilePrivilege         Attributes - 
 17 0x000000011 SeBackupPrivilege                 Attributes - 
 18 0x000000012 SeRestorePrivilege                Attributes - 
 19 0x000000013 SeShutdownPrivilege               Attributes - 
 20 0x000000014 SeDebugPrivilege                  Attributes - 
 22 0x000000016 SeSystemEnvironmentPrivilege      Attributes - 
 23 0x000000017 SeChangeNotifyPrivilege           Attributes - Enabled Default 
 24 0x000000018 SeRemoteShutdownPrivilege         Attributes - 
 25 0x000000019 SeUndockPrivilege                 Attributes - 
 28 0x00000001c SeManageVolumePrivilege           Attributes - 
 29 0x00000001d SeImpersonatePrivilege            Attributes - Enabled Default 
 30 0x00000001e SeCreateGlobalPrivilege           Attributes - Enabled Default 
 33 0x000000021 SeIncreaseWorkingSetPrivilege     Attributes - 
 34 0x000000022 SeTimeZonePrivilege               Attributes - 
 35 0x000000023 SeCreateSymbolicLinkPrivilege     Attributes - 
Authentication ID:         (0,14e4c)
Impersonation Level:       Anonymous
TokenType:                 Primary
Source: User32             TokenFlags: 0x2000 ( Token in use )
Token ID: d166b            ParentToken ID: 0
Modified ID:               (0, d052f)
RestrictedSidCount: 0      RestrictedSids: 00000000
OriginatingLogonSession: 3e7

... and here is an ACCESS_TOKEN for a process normally run by the same user with "Run as administrator".

TS Session ID: 0x1
User: S-1-5-21-2452432034-249115698-1235866470-1000 (no name mapped)
User Groups: 
 00 S-1-5-21-2452432034-249115698-1235866470-513 (no name mapped)
    Attributes - Mandatory Default Enabled 
 01 S-1-1-0 (Well Known Group: localhost\Everyone)
    Attributes - Mandatory Default Enabled 
 02 S-1-5-32-544 (Alias: BUILTIN\Administrators)
    Attributes - Mandatory Default Enabled Owner 
 03 S-1-5-32-545 (Alias: BUILTIN\Users)
    Attributes - Mandatory Default Enabled 
 04 S-1-5-4 (Well Known Group: NT AUTHORITY\INTERACTIVE)
    Attributes - Mandatory Default Enabled 
 05 S-1-2-1 (Well Known Group: localhost\CONSOLE LOGON)
    Attributes - Mandatory Default Enabled 
 06 S-1-5-11 (Well Known Group: NT AUTHORITY\Authenticated Users)
    Attributes - Mandatory Default Enabled 
 07 S-1-5-15 (Well Known Group: NT AUTHORITY\This Organization)
    Attributes - Mandatory Default Enabled 
 08 S-1-5-5-0-85516 (no name mapped)
    Attributes - Mandatory Default Enabled LogonId 
 09 S-1-2-0 (Well Known Group: localhost\LOCAL)
    Attributes - Mandatory Default Enabled 
 10 S-1-5-64-10 (Well Known Group: NT AUTHORITY\NTLM Authentication)
    Attributes - Mandatory Default Enabled 
 11 S-1-16-12288 (Label: Mandatory Label\High Mandatory Level)
    Attributes - GroupIntegrity GroupIntegrityEnabled 
Primary Group: S-1-5-21-2452432034-249115698-1235866470-513 (no name mapped)
 05 0x000000005 SeIncreaseQuotaPrivilege          Attributes - 
 08 0x000000008 SeSecurityPrivilege               Attributes - 
 09 0x000000009 SeTakeOwnershipPrivilege          Attributes - 
 10 0x00000000a SeLoadDriverPrivilege             Attributes - 
 11 0x00000000b SeSystemProfilePrivilege          Attributes - 
 12 0x00000000c SeSystemtimePrivilege             Attributes - 
 13 0x00000000d SeProfileSingleProcessPrivilege   Attributes - 
 14 0x00000000e SeIncreaseBasePriorityPrivilege   Attributes - 
 15 0x00000000f SeCreatePagefilePrivilege         Attributes - 
 17 0x000000011 SeBackupPrivilege                 Attributes - 
 18 0x000000012 SeRestorePrivilege                Attributes - 
 19 0x000000013 SeShutdownPrivilege               Attributes - 
 20 0x000000014 SeDebugPrivilege                  Attributes - 
 22 0x000000016 SeSystemEnvironmentPrivilege      Attributes - 
 23 0x000000017 SeChangeNotifyPrivilege           Attributes - Enabled Default 
 24 0x000000018 SeRemoteShutdownPrivilege         Attributes - 
 25 0x000000019 SeUndockPrivilege                 Attributes - 
 28 0x00000001c SeManageVolumePrivilege           Attributes - 
 29 0x00000001d SeImpersonatePrivilege            Attributes - Enabled Default 
 30 0x00000001e SeCreateGlobalPrivilege           Attributes - Enabled Default 
 33 0x000000021 SeIncreaseWorkingSetPrivilege     Attributes - 
 34 0x000000022 SeTimeZonePrivilege               Attributes - 
 35 0x000000023 SeCreateSymbolicLinkPrivilege     Attributes - 
Authentication ID:         (0,14e4c)
Impersonation Level:       Anonymous
TokenType:                 Primary
Source: User32             TokenFlags: 0x2000 ( Token in use )
Token ID: ce282            ParentToken ID: 0
Modified ID:               (0, cddbd)
RestrictedSidCount: 0      RestrictedSids: 00000000
OriginatingLogonSession: 3e7

As you see, the only difference is the token ID:

Token ID: d166b            ParentToken ID: 0
Modified ID:               (0, d052f)


Token ID: ce282            ParentToken ID: 0
Modified ID:               (0, cddbd)

Sorry, I can't add much light into this yet, but I am still digging.

How to switch text case in visual studio code

To have in Visual Studio Code what you can do in Sublime Text ( CTRL+K CTRL+U and CTRL+K CTRL+L ) you could do this:

  • Open "Keyboard Shortcuts" with click on "File -> Preferences -> Keyboard Shortcuts"
  • Click on "keybindings.json" link which appears under "Search keybindings" field
  • Between the [] brackets add:

        "key": "ctrl+k ctrl+u",
        "command": "editor.action.transformToUppercase",
        "when": "editorTextFocus"
        "key": "ctrl+k ctrl+l",
        "command": "editor.action.transformToLowercase",
        "when": "editorTextFocus"
  • Save and close "keybindings.json"

Another way:
Microsoft released "Sublime Text Keymap and Settings Importer", an extension which imports keybindings and settings from Sublime Text to VS Code. -

Excel VBA - Pass a Row of Cell Values to an Array and then Paste that Array to a Relative Reference of Cells

No need for array. Just use something like this:


    Dim Rng As Range
    Dim Number_of_Sims As Long
    Dim i As Long
    Number_of_Sims = 10

    Set Rng = Range("C4:G4")
    For i = 1 To Number_of_Sims
       Rng.Offset(i, 0).Value = Rng.Value
       Worksheets("Sheetname").Calculate   'replacing Sheetname with name of your sheet

End Sub

How to create empty constructor for data class in Kotlin Android

I'd suggest to modify the primary constructor and add a default value to each parameter:

data class Activity(
    var updated_on: String = "",
    var tags: List<String> = emptyList(),
    var description: String = "",
    var user_id: List<Int> = emptyList(),
    var status_id: Int = -1,
    var title: String = "",
    var created_at: String = "",
    var data: HashMap<*, *> = hashMapOf<Any, Any>(),
    var id: Int = -1,
    var counts: LinkedTreeMap<*, *> = LinkedTreeMap<Any, Any>()

You can also make values nullable by adding ? and then you can assing null:

data class Activity(
    var updated_on: String? = null,
    var tags: List<String>? = null,
    var description: String? = null,
    var user_id: List<Int>? = null,
    var status_id: Int? = null,
    var title: String? = null,
    var created_at: String? = null,
    var data: HashMap<*, *>? = null,
    var id: Int? = null,
    var counts: LinkedTreeMap<*, *>? = null

In general, it is a good practice to avoid nullable objects - write the code in the way that we don't need to use them. Non-nullable objects are one of the advantages of Kotlin compared to Java. Therefore, the first option above is preferable.

Both options will give you the desired result:

val activity = Activity()
activity.title = "New Computer"

iPhone/iOS JSON parsing tutorial

As of iOS 5.0 Apple provides the NSJSONSerialization class "to convert JSON to Foundation objects and convert Foundation objects to JSON". No external frameworks to incorporate and according to benchmarks its performance is quite good, significantly better than SBJSON.

500.21 Bad module "ManagedPipelineHandler" in its module list

This is because IIS 7 uses http handlers from both <system.web><httpHandlers> and <system.webServer><handlers>. if you need CloudConnectHandler in your application, you should add <httpHandlers> section with this handler to the <system.web>:

    <add verb="*" path="CloudConnect.aspx" type="CloudConnectHandler" />

and also add preCondition attribute to the handler in <system.webServer>:

  <add name="CloudConnectHandler" verb="*" path="CloudConnect.aspx" type="CloudConnectHandler" preCondition="integratedMode" />

Hope it helps

Select all from table with Laravel and Eloquent

There are 3 ways that one can do that.


$entireTable = TableModelName::all();


$posts = Posts::get(); 
  1. put this line before the class in the controller

    use Illuminate\Support\Facades\DB; // this will import the DB facade into your controller class

Now in the class

$posts = DB::table('posts')->get(); // it will get the entire table
  1. put this line before the class in the controller

    Same import the DB facade like method 2

Now in the controller

$posts = DB::select('SELECT * FROM posts');

SDK Location not found Android Studio + Gradle

I found the solution here:

Just create a file and add a line with sdk.dir=SDK_LOCATION

Unable to use Intellij with a generated sources folder

I had the same issue with Eclipse a couple of months ago when importing my project. Now I had the same with intelliJ. Here is how someone helped me to solve this in IntelliJ:

Menu => View => Tools windows => Maven Project In the spring_user value => Run Configuration, choose clean install. This should do a clean install and after this you should be able to see the classes enter image description here

jQuery: Performing synchronous AJAX requests

how remote is that url ? is it from the same domain ? the code looks okay

try this

$.get(remote_url, function(data) { remote = data; });
// or
remote = $.get(remote_url).responseText;