Pattern Execution

The following diagram summarizes the execution flow of a pattern. Next sections detail each of the phases.

Main function: patterns_start_engine()

Once a pattern has been parsed after being enabled or run, the function patterns_start_engine() goes into action. This function receives a Pattern object, the execution mode (php or batch) and a set of extra parameters if needed. The diagram below summarizes the main steps involved before calling the proper (PHP or batch) function:

• As an example, a simple Pattern object generated after running the node.yaml example has the following structure:

  $pattern	stdClass	
  	CLASSNAME	stdClass	
  	pid	1	
  	name	node.yaml	
  	format	yaml	
  	status	1	
  	public	0	
  	file	sites/all/modules/custom/patterns/patterns_examples/patterns//node.yaml	
  	updated	1348051211	
  	enabled	1348479432	
  	title	Example Article creation	
  	description	Creates an example article node	
  	pattern	Array [2]	
  		info	Array [7]	
  			title	Example Article creation	
  			description	Creates an example article node	
  			author	QSCience	
  			version	1.0	
  			category	Content	
  			core	7.x	
  			author_website	http://qlectives.eu/	
  		actions	Array [1]	
  			0	Array [1]	
  				create	Array [4]	
  					tag	node	
  					type	article	
  					title	Test Article	
  					body	lorem ipsum ...	
  

• Using the same example, the $parameters array has this structure:
  

  $params	Array [10]	
  	pid	1	
  	execution	extend	
  	mode	php	
  	run-subpatterns	never	
  	confirm	1	
  	submit	Confirm	
  	form_build_id	form-uEtwhgIz5faBmzn7DBL-AGDkqUE0E3YaDj5yHdO8tpI	
  	form_token	zTBMxkjkiecd-A26XPB47LqaVap1qUsA-smXtsC37Q0	
  	form_id	patterns_enable_pattern	
  	op	Confirm	
  

• The Pattern object is passed afterwards to an auxiliary parsing function called patterns_parser_get_pattern_details() (includes/parser.inc). Internally, this function carries out a scanning and results validation process in the same way as it is detailed in the previous subsection “Enabling a pattern" by the functions patterns_enable_pattern() and patterns_enable_pattern_submit()”.
• But the result is an array whose index is the Pattern ID. Following the same example we have used previously and being 1 the PID, the result of our execution would be:

  $patterns_details	Array [1]	
  	1	Array [3]	
  		info	Array [7]	
  			title	Example Article creation	
  			description	Creates an example article node	
  			author	QSCience	
  			version	1.0	
  			category	Content	
  			core	7.x	
  			author_website	http://qlectives.eu/	
  		sections	Array [1]	
  			actions	Array [1]	
  				0	Array [1]	
  					create	Array [4]	
  		modules	Array [0]
  

• Afterwards, this array is decomposed into the PID and the different parts that compose the pattern ($info, $modules and $sections) (in the future it will be able to process several patterns from the same file).
• The function later calls patterns_install_modules() (includes/modules.inc), that will enable all the required modules to run that pattern.
• Then another temporal variable called $actions_map is build. This variable will be passed also to the proper execution function. This variable is obsolete (comes from the re-writting process from Patterns v.6) and it will be removed in future versions. Following our example, the $actions_map variable looks like:

  $actions_map	Array [2]	
  	patterns	Array [1]	
  		1	Array [7]	
  			title	Example Article creation	
  			description	Creates an example article node	
  			author	QSCience	
  			version	1.0	
  			category	Content	
  			core	7.x	
  			author_website	http://qlectives.eu/	
  	map	<Uninitialized>	
  

• Finally, depending on the running mode (batch or php) a different function will be called: patterns_execute_pattern_php() or patterns_execute_pattern_batch().