[Stack-cvs] stack-dev/lib/blocks BlockInterface.php,NONE,1.2.8.2

[Ben H. <bdv...@us...>]

Update of /cvsroot/stack/stack-dev/lib/blocks
In directory sfp-cvsdas-3.v30.ch3.sourceforge.com:/tmp/cvs-serv29766/lib/blocks

Added Files:
      Tag: question_reporting
	BlockInterface.php 
Log Message:
Merging from the current HEAD into question_reporting. Apologies in advance if this all goes horribly wrong.

--- NEW FILE: BlockInterface.php ---
<?php
/**
*
* Welcome to STACK.  A system for teaching and assessment using a
* computer algebra kernel.
*
* This file is licensed under the GPL License.
*
* A copy of the license is in your STACK distribution called
* license.txt.  If you are missing this file you can obtain
* it from:
* http://www.stack.bham.ac.uk/license.txt
*
*
* @author Matti Harjula
*
*/

require_once("../ui/BlockHandler.php");

/**
* Block class "interface". All blocks must implement this "interface". All blocks 
* must also be stored in /lib/blocks/active/ and named as *Block and placed in 
* files named *Block.php
*/
abstract class BlockInterface
{
	/**
	* Returns the possible identifiers of "pseudo-blocks" that should be 
	* ignored by the parser when inside this type of an block.
	*
	* This is used to define substructure for blocks using the same block-syntax
	* as with real blocks. The main example is the if-else-if:
	*  {% if something %}
	*  {% else %} <= That is not a start tag for an else-block it is just 
	*                internal structure of the if block and the parser should 
	*                ignore it. Naturally, should it exist somewhere where it is 
	*                not a direct child of an if-block it must be considered as  
	*                a syntax error.  
	*  {% end if %}
	*
	* Returns an empty array or false if no identifiers are needed.
	*
	* @return array of strings e.g. array("else") for the if-else-if block 
	*/
	abstract public function getSubBlockIdentifiers();

	/**
	* Returns the identifier of this block. If this is a "for"-block we return 
	* "for".
	*
	* @return string
	*/
	abstract public function getBlockIdentifier();


	/**
	* Processes the blocks contents. Then returns the processed contents.
	*
	* @param string $blockContent
	* @param array $blockVars Maxima strings of the evaluated variables 
	* @param object $casTextHandler can be used to evaluate the content of this 
	*        block if needed. May be needed when block needs to act on the 
	*        real contents of the block. For example when the contents of this 
	*        block are used as the source code for something it may be necessary 
	*        evaluate possible if and for blocks beforehand.  
	*         
	*
	*
	* @return string the processed string that replaces the original content 
	*         of this block
	*/
	abstract public function processBlock($blockContent,$blockVars,$casTextHandler);




}

?>