Royal Tutorials

Javascript isArray

Björn Ali Göransson — Mon, 06 Feb 2012 23:16:53 +0000

To check wether a variable contains an Array in Javascript, use the following code:

var foo = [];

if(foo instanceof Array){
  alert("Foo is an array!");
}

Note: This does not work when accessing iframe contents.

PHP inline object

Björn Ali Göransson — Mon, 06 Feb 2012 04:55:52 +0000

To make a PHP object “inline” – that is to instantiate the object and populate its properties in one statement – use the following code:

$my_obj = (object) array("foo" => 1, "bar" => 2);

Also, this can be used when constructing JSON output, for example:

json_encode(
  array(
    my_array => array("foo", "bar"),
    my_obj => (object) array(
      "foo" => 1,
      "bar" => 2
    )
  )
);

WP_Filesystem init

Björn Ali Göransson — Mon, 23 Jan 2012 00:58:03 +0000

When working with some internal WordPress functions, sometimes you get a “fs_unavailable” “Could not access filesystem” error, and if you look at the source code, there is a comment that says: “Assumes that WP_Filesystem() has already been called and set up”, you might wonder how to call and setup the WP_Filesystem.

To do this, just do the following before you call your function:

WP_Filesystem();

//unzip_file etc …

ZWAMP Unable to allocate memory for pool

Björn Ali Göransson — Wed, 18 Jan 2012 16:59:19 +0000

When using ZWAMP and running a non-trivial PHP script, the said error might occur several times. This is because the APC (which is enabled by default in ZWAMP) runs out of space when caching.

To fix this, go to the folder vdrive\.sys\php\php.ini in your ZWAMP folder, and look for the following code:

apc.shm_size=4M

Change 4M to something like 12M.

ZWAMP Your PHP installation appears to be missing the MySQL extension which is required by WordPress

Björn Ali Göransson — Tue, 17 Jan 2012 20:05:13 +0000

To install WordPress on the ZWAMP portable server, you need to enable the native MySQL extension in PHP. By default, only the PDY MySQL extension is enabled.

To enable the native MySQL extension in PHP, go to the folder vdrive\.sys\php\php.ini in your ZWAMP folder, and look for the following code:

;extension=php_mysql.dll

Remove the semicolon, save the file, and restart the server.

PHP unCamelCase

Björn Ali Göransson — Tue, 13 Dec 2011 11:31:17 +0000

To convert a string from CamelCase to underscore_notation in PHP, use the following code:

$my_camel_case_string = "fooBar";

$resulting_string = strtolower(preg_replace("[A-Z]", "_\$1", $my_camel_case_string));

$my_un_camel_cased_string = $resulting_string;

The code can be made into a function like this:

function un_camel_case($string){
  return strtolower(preg_replace("[A-Z]", "_\$1", $string));
}

EPiServer change master language

Björn Ali Göransson — Sun, 27 Nov 2011 18:16:48 +0000

To change the default language for a website in EPiServer, add the language attribute to all your elements inside the , section inside EPiServerFramework.config.

The following code changes the default language to swedish:


  
    language="sv" />
    language="sv" />
    language="sv" />

No VirtualPathProvider is set to handler Page files or the virtualPath attribute is invalid.

Björn Ali Göransson — Sun, 27 Nov 2011 18:03:02 +0000

When configuring an EPiServer site (sometimes migrated from 4.62 with upload paths), you might encounter this error when experimenting with the new VPP section in EPiServer.config.

The problem is that the currently used element has a pageFolderVirtualPathProvider attribute that points to an (inside the , section) with a virtualPath attribute, for which no match is found.

To fix this, change the pageFolderVirtualPathProvider attribute to point to the virtualPath attribute of an existing element.

The following code contains such a fix:

…

Javascript popup onclose

Björn Ali Göransson — Sun, 20 Nov 2011 01:23:52 +0000

To make a callback function fire whenever your popup window is closed, use the following code:

var myWindow = … // create window popup
var callback = function(){
  alert("foo");
};

$(myWindow).unload(function(){
  if(this.location == "about:blank"){
    $(myWindow).unload(callback);
  } else {
    callback();
  }
});

Note: The fix for “about:blank” is needed for browsers who create popups with about:blank, then navigate to the specified URL. Also, this callback will fire whenever you navigate away from the initial popup page, not just closing.

Another solution is to continously poll for window closure. See the following code:

var myWindow = … // create window popup
var callback = function(){
  alert("foo");
};

function pollForWindowClosure(){
  if(myWindow.closed){
    callback();
    return;
  }

  setTimeout(pollForWindowClosure, 10);
}

pollForWindowClosure();

jQuery load CSS callback

Björn Ali Göransson — Sat, 19 Nov 2011 01:07:50 +0000

To load a CSS file asynchronously with jQuery while providing a callback function for when the file has been included, use the following code:

var stylesheet = "foo.css";
var callback = function(){
  alert("CSS is now included");
};

$.get(stylesheet, function(contents){
  $("").appendTo(document.head);
  callback();
});