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diff --git a/user_guide_src/source/libraries/parser.rst b/user_guide_src/source/libraries/parser.rst new file mode 100644 index 000000000..0b77ae4b9 --- /dev/null +++ b/user_guide_src/source/libraries/parser.rst @@ -0,0 +1,149 @@ +##################### +Template Parser Class +##################### + +The Template Parser Class enables you to parse pseudo-variables +contained within your view files. It can parse simple variables or +variable tag pairs. If you've never used a template engine, +pseudo-variables look like this:: + + <html> + <head> + <title>{blog_title}</title> + </head> + <body> + + <h3>{blog_heading}</h3> + + {blog_entries} + <h5>{title}</h5> + <p>{body}</p> + {/blog_entries} + </body> + </html> + +These variables are not actual PHP variables, but rather plain text +representations that allow you to eliminate PHP from your templates +(view files). + +.. note:: CodeIgniter does **not** require you to use this class since + using pure PHP in your view pages lets them run a little faster. + However, some developers prefer to use a template engine if they work + with designers who they feel would find some confusion working with PHP. + +.. important:: The Template Parser Class is **not** a full-blown + template parsing solution. We've kept it very lean on purpose in order + to maintain maximum performance. + +Initializing the Class +====================== + +Like most other classes in CodeIgniter, the Parser class is initialized +in your controller using the $this->load->library function:: + + $this->load->library('parser'); + +Once loaded, the Parser library object will be available using: +$this->parser + +The following functions are available in this library: + +$this->parser->parse() +====================== + +This method accepts a template name and data array as input, and it +generates a parsed version. Example:: + + $this->load->library('parser'); + + $data = array( + 'blog_title' => 'My Blog Title', + 'blog_heading' => 'My Blog Heading' + ); + + $this->parser->parse('blog_template', $data); + +The first parameter contains the name of the :doc:`view +file <../general/views>` (in this example the file would be called +blog_template.php), and the second parameter contains an associative +array of data to be replaced in the template. In the above example, the +template would contain two variables: {blog_title} and {blog_heading} + +There is no need to "echo" or do something with the data returned by +$this->parser->parse(). It is automatically passed to the output class +to be sent to the browser. However, if you do want the data returned +instead of sent to the output class you can pass TRUE (boolean) to the +third parameter:: + + $string = $this->parser->parse('blog_template', $data, TRUE); + +$this->parser->parse_string() +============================== + +This method works exactly like parse(), only accepts a string as the +first parameter in place of a view file. + +Variable Pairs +============== + +The above example code allows simple variables to be replaced. What if +you would like an entire block of variables to be repeated, with each +iteration containing new values? Consider the template example we showed +at the top of the page:: + + <html> + <head> + <title>{blog_title}</title> + </head> + <body> + + <h3>{blog_heading}</h3> + + {blog_entries} + <h5>{title}</h5> + <p>{body}</p> + {/blog_entries} + </body> + </html> + +In the above code you'll notice a pair of variables: {blog_entries} +data... {/blog_entries}. In a case like this, the entire chunk of data +between these pairs would be repeated multiple times, corresponding to +the number of rows in a result. + +Parsing variable pairs is done using the identical code shown above to +parse single variables, except, you will add a multi-dimensional array +corresponding to your variable pair data. Consider this example:: + + $this->load->library('parser'); + + $data = array( + 'blog_title' => 'My Blog Title', + 'blog_heading' => 'My Blog Heading', + 'blog_entries' => array( + array('title' => 'Title 1', 'body' => 'Body 1'), + array('title' => 'Title 2', 'body' => 'Body 2'), + array('title' => 'Title 3', 'body' => 'Body 3'), + array('title' => 'Title 4', 'body' => 'Body 4'), + array('title' => 'Title 5', 'body' => 'Body 5') + ) + ); + + $this->parser->parse('blog_template', $data); + +If your "pair" data is coming from a database result, which is already a +multi-dimensional array, you can simply use the database result_array() +function:: + + $query = $this->db->query("SELECT * FROM blog"); + + $this->load->library('parser'); + + $data = array( + 'blog_title' => 'My Blog Title', + 'blog_heading' => 'My Blog Heading', + 'blog_entries' => $query->result_array() + ); + + $this->parser->parse('blog_template', $data); + |