Opt Instruction Expression

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Opt_Instruction_Expression
Project	Open Power Template 2
Type	Instruction
Author	Tomasz Jędrzejewski
Website	http://www.invenzzia.org/
License	New BSD License
Status	No information

The instruction adds the opt:expression tag. It allows you to write a group of OPT expressions without the curly brackets that will be executed one after another. The new line works as an expression separator.

Source code

Below you can find a source code of the instruction. You can install it either as a OPT plugin or manually.

<?php
/*
 * An extra instruction that adds the "opt:expression" tag to OPT.
 *
 * Author: Tomasz "Zyx" Jędrzejewski <http://www.invenzzia.org>
 * License: New BSD License <http://www.invenzzia.org/license/new-bsd>
 */
 
	class Opt_ExpressionInvalidContent_Exception extends Opt_Instruction_Exception
	{
		protected $_message = 'The opt:expression tag may contain only the text data.';
	} // end Opt_ExpressionInvalidContent_Exception;
 
	class Opt_Instruction_Expression extends Opt_Compiler_Processor
	{
		public function configure()
		{
			$this->_addInstructions(array('opt:expression'));
		} // end configure();
 
		public function processNode(Opt_Xml_Node $node)
		{
			if($node->countChildren() != 1 || ! $node->getLastChild() instanceof Opt_Xml_Text)
			{
				throw new Opt_ExpressionInvalidContent_Exception();
			}
			if($node->getLastChild()->countChildren() != 1 || ! $node->getLastChild()->getLastChild() instanceof Opt_Xml_Cdata)
			{
				throw new Opt_ExpressionInvalidContent_Exception();
			}
 
			// Extract the code
			$lines = explode("\n", (string)$node->getLastChild()->getLastChild());
			foreach($lines as $line)
			{
				$line = trim($line);
				if($line != '')
				{
					$expression = $this->_compiler->compileExpression(trim($line), true, Opt_Compiler_Class::ESCAPE_OFF);
					$node->addAfter(Opt_Xml_Buffer::TAG_SINGLE_AFTER, $expression[0].'; ');
				}
			}
 
			$node->set('single', true);
			$node->removeChildren();
		} // end processNode();
	} // end Opt_Instruction_Expression;

Installation instructions:

1. Copy the file somewhere.
2. Register the class in the autoloader: Opl_Loader::mapAbsolute('Opt_Instruction_Expression', './some/path');
3. Register the instruction in OPT: $tpl->register(Opt_Class::OPT_INSTRUCTION, 'Expression');

Plugin installation:

1. Save the code above as a file instruction.Expression.php in your OPT plugin directory.
2. Ensure that the plugin support is active in your script.
3. Enjoy.

Usage

The opt:expression tag may contain only the text data with the expressions. No other XML nodes are allowed:

<opt:expression>
  @hello is 'Hi universe'
 
  $a is $foo + $bar
  $text is spacify($text, '-')  
</opt:expression>
 
<p>{$a}, {$text}</p>

Every expression must be written in the new line. Blank lines are omitted and ignored.