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Derek Jones	8ede1a2	2011-10-05 13:34:52 -0500	[diff] [blame]	1	#####################
				2	Template Parser Class
				3	#####################
				4
				5	The Template Parser Class enables you to parse pseudo-variables
				6	contained within your view files. It can parse simple variables or
				7	variable tag pairs. If you've never used a template engine,
				8	pseudo-variables look like this::
				9
Derek Jones	eb946d0	2011-10-05 15:47:43 -0500	[diff] [blame]	10	<html>
				11	<head>
				12	<title>{blog_title}</title>
				13	</head>
				14	<body>
				15
				16	<h3>{blog_heading}</h3>
				17
				18	{blog_entries}
				19	<h5>{title}</h5>
				20	<p>{body}</p>
				21	{/blog_entries}
				22	</body>
				23	</html>
Derek Jones	8ede1a2	2011-10-05 13:34:52 -0500	[diff] [blame]	24
				25	These variables are not actual PHP variables, but rather plain text
				26	representations that allow you to eliminate PHP from your templates
				27	(view files).
				28
				29	.. note:: CodeIgniter does not require you to use this class since
				30	using pure PHP in your view pages lets them run a little faster.
				31	However, some developers prefer to use a template engine if they work
				32	with designers who they feel would find some confusion working with PHP.
				33
				34	.. important:: The Template Parser Class is not a full-blown
				35	template parsing solution. We've kept it very lean on purpose in order
				36	to maintain maximum performance.
				37
				38	Initializing the Class
				39	======================
				40
				41	Like most other classes in CodeIgniter, the Parser class is initialized
				42	in your controller using the $this->load->library function::
				43
				44	$this->load->library('parser');
				45
				46	Once loaded, the Parser library object will be available using:
				47	$this->parser
				48
				49	The following functions are available in this library:
				50
				51	$this->parser->parse()
				52	======================
				53
				54	This method accepts a template name and data array as input, and it
				55	generates a parsed version. Example::
				56
Derek Jones	eb946d0	2011-10-05 15:47:43 -0500	[diff] [blame]	57	$this->load->library('parser');
				58
				59	$data = array(
				60	'blog_title' => 'My Blog Title',
				61	'blog_heading' => 'My Blog Heading'
				62	);
				63
				64	$this->parser->parse('blog_template', $data);
Derek Jones	8ede1a2	2011-10-05 13:34:52 -0500	[diff] [blame]	65
				66	The first parameter contains the name of the :doc:`view
				67	file <../general/views>` (in this example the file would be called
				68	blog_template.php), and the second parameter contains an associative
				69	array of data to be replaced in the template. In the above example, the
				70	template would contain two variables: {blog_title} and {blog_heading}
				71
				72	There is no need to "echo" or do something with the data returned by
				73	$this->parser->parse(). It is automatically passed to the output class
				74	to be sent to the browser. However, if you do want the data returned
				75	instead of sent to the output class you can pass TRUE (boolean) to the
				76	third parameter::
				77
				78	$string = $this->parser->parse('blog_template', $data, TRUE);
				79
				80	$this->parser->parse_string()
				81	==============================
				82
				83	This method works exactly like parse(), only accepts a string as the
				84	first parameter in place of a view file.
				85
				86	Variable Pairs
				87	==============
				88
				89	The above example code allows simple variables to be replaced. What if
				90	you would like an entire block of variables to be repeated, with each
				91	iteration containing new values? Consider the template example we showed
				92	at the top of the page::
				93
Derek Jones	eb946d0	2011-10-05 15:47:43 -0500	[diff] [blame]	94	<html>
				95	<head>
				96	<title>{blog_title}</title>
				97	</head>
				98	<body>
				99
				100	<h3>{blog_heading}</h3>
				101
				102	{blog_entries}
				103	<h5>{title}</h5>
				104	<p>{body}</p>
				105	{/blog_entries}
				106	</body>
				107	</html>
Derek Jones	8ede1a2	2011-10-05 13:34:52 -0500	[diff] [blame]	108
				109	In the above code you'll notice a pair of variables: {blog_entries}
				110	data... {/blog_entries}. In a case like this, the entire chunk of data
				111	between these pairs would be repeated multiple times, corresponding to
				112	the number of rows in a result.
				113
				114	Parsing variable pairs is done using the identical code shown above to
				115	parse single variables, except, you will add a multi-dimensional array
				116	corresponding to your variable pair data. Consider this example::
				117
Derek Jones	eb946d0	2011-10-05 15:47:43 -0500	[diff] [blame]	118	$this->load->library('parser');
				119
				120	$data = array(
				121	'blog_title' => 'My Blog Title',
				122	'blog_heading' => 'My Blog Heading',
				123	'blog_entries' => array(
				124	array('title' => 'Title 1', 'body' => 'Body 1'),
				125	array('title' => 'Title 2', 'body' => 'Body 2'),
				126	array('title' => 'Title 3', 'body' => 'Body 3'),
				127	array('title' => 'Title 4', 'body' => 'Body 4'),
				128	array('title' => 'Title 5', 'body' => 'Body 5')
				129	)
				130	);
				131
				132	$this->parser->parse('blog_template', $data);
Derek Jones	8ede1a2	2011-10-05 13:34:52 -0500	[diff] [blame]	133
				134	If your "pair" data is coming from a database result, which is already a
				135	multi-dimensional array, you can simply use the database result_array()
				136	function::
				137
Derek Jones	eb946d0	2011-10-05 15:47:43 -0500	[diff] [blame]	138	$query = $this->db->query("SELECT * FROM blog");
				139
				140	$this->load->library('parser');
				141
				142	$data = array(
				143	'blog_title' => 'My Blog Title',
				144	'blog_heading' => 'My Blog Heading',
				145	'blog_entries' => $query->result_array()
				146	);
				147
				148	$this->parser->parse('blog_template', $data);
Derek Jones	8ede1a2	2011-10-05 13:34:52 -0500	[diff] [blame]	149