User:Pavithraes/Sandbox/Extension:Loops

The Loops extension provides parser functions for performing loops. Currently, version 1.0.0 is in development, that will feature extension registration, tracking categories for pages with too many loops, and parser tests to avoid regressions. The documentation below targets the latest stable release, v0.5.2.

performs a loop (i.e. it repeatedly parses a given wiki markup block statement) so long as the condition mark-up evaluates to non-whitespace.


 * Examples

The wiki markup:

produces the following:


 * 0
 * 1
 * 2
 * 3
 * 4

can also be used in a template to simulate a numbered array. If the page "Template:Loops Test" contains

then the wiki-markup

produces


 * zero
 * one
 * two
 * three
 * four

It's important to note that whitespace, including newlines, tabs, and spaces, is stripped from the beginning and end of all the arguments of these parser functions. If this is not desirable, adding any non-whitespace characters (including the HTML encoding for a whitespace character ) will prevent further stripping (hence the &lt;nowiki/&gt; tags in the above examples).

performs exactly like, with the exception that the block statement is guaranteed to be parsed and displayed (if it results in displayable text) at least once. This is done before the condition text is evaluated.

repeatedly parses and displays &lt;wiki markup> a number of times equal to the absolute value of &lt;number of loops to be performed>. &lt;Starting value> is placed in a variable (accessible by Variables extension's  parser function) using the name &lt;variable name>. After each loop, the variable is incremented by one if &lt;number of loops to be performed> is positive, or decremented by one if &lt;number of loops to be performed> is negative.

Note:  From all loop functions,  should have the best performance since there is no condition which has to be expanded and validated for each cycle.

The following code:
 * Examples

produces


 * This is round 4 and we have 3 more to go
 * This is round 5 and we have 2 more to go
 * This is round 6 and we have 1 more to go
 * This is round 7 and we have 0 more to go

(experimental)
is to be used in templates. It takes arguments that are passed to the template and puts them in variables accessible by Variables extension's  parser function.

This function iterates through each argument whose name begins with &lt;prefix>. With each iteration it puts the argument name minus &lt;prefix> into &lt;key> as if calling. It then takes the value of the argument and puts it into &lt;value> in a similar method. The block statement is then expanded. The block statement may contain  and   to access the stored arguments.

If the page "Template:Loops Test" contains
 * Example

then the wiki markup

produces


 * 1 = val1
 * 5 = val5
 * ument = value

(experimental)
performs similarly to  with two major differences:  It doesn't take a prefix argument, and it only works on numbered arguments whether they're explicitly numbered,

or implicitly numbered.

Mixing these methods in a single template call may cause values to get overwritten, so be careful.

If "Template:Loops Test" is edited to contain:
 * Examples

then

will result in


 * 1 = Apricot
 * 2 = Caramel slice
 * 5 = Eclair

Configuration
These configuration variables have to be set in the "LocalSettings.php" file after the inclusion of this extension.


 * : This parameter sets the maximum number of loops a page is allowed to perform (default ). Setting it to   lets the loops run within the limits of phps environment.  This parameter affects neither the   nor   parser functions.


 * : Configuration variable (array) to define which Loops functions should be enabled. By default, all functions are enabled if the Variables extension is installed as well. If the Variables extension is not installed,,   and   will be disabled since they do not work without it being installed. To enable the   and   functions only, one can use: