Subversion Repositories SmartDukaan

<?php

/**
 * A meta tag generation library for CodeIgniter.
 * 
 * Copyright (c) 2009 Per Sikker Hansen
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 * 
 * Usage example:
 * -------------------
 * $config['doctype'] = 'xhtml';
 * $this->load->library('meta_tags');
 * $this->meta_tags->initialize($config);
 * $this->meta_tags->set_meta_tag('author', 'Per Sikker Hansen');
 * $this->meta_tags->add_robots_rule('NOINDEX');
 * $this->meta_tags->add_keyword('php');
 * echo $this->meta_tags->generate_meta_tags();
 * -------------------
 * Optionally you can store a default configuration array in config.php with this prototype:
 * $config['meta_tags']['doctype'] = 'xhtml';
 * $config['meta_tags']['tags'] = array('tagname'=>'tagcontent', 'another tag'=>'some other content');
 * $config['meta_tags']['robots'] = array('NOINDEX', 'FOLLOW', 'NOARCHIVE');
 * $config['meta_tags']['keywords'] = array('great', 'php', 'framework');
 * 
 * @author Per Sikker Hansen <per@sikker-hansen.dk>
 */
class Meta_tags {
    
    var $CI;
    var $doctype;
    var $tags;
    var $keywords;
    var $robots;
    
    /**
     * Class constructor with optional parameter, which calls the initialize() method
     * @param $config array optional array containing configuration
     */
    function Meta_tags($config = array())
    {
        $this->CI =& get_instance();
        $this->initialize($config);
    }
    
    /**
     * Initializes the library with the configuration given either in a parameter or in config.php
     * @param $config array optional array containing configuration and global default meta tags
     */
    function initialize($config = array())
    {
        if(empty($config))
        {
            $config = $this->CI->config->item('meta_tags');
            if(!$config)
                $config = array();
        }

        if(isset($config['doctype']))
        {
            $this->doctype = $config['doctype'];
        }
        else
        {
            $this->doctype = 'xhtml'; //if no doctype is given, default to XHTML
        }      

        if(isset($config['tags']))
            $this->tags = $config['tags'];
        
        if(isset($config['keywords']))
            $this->keywords = $config['keywords'];
            
        if(isset($config['robots']))
            $this->robots = $config['robots'];
    }

    /**
     * Sets the doctype for which the tags will be generated
     * @param $doctype string choices are 'xhtml' and 'html'
     */
    function set_doctype($doctype)
    {
        $this->doctype = $doctype;
    }
    
    /**
     * Sets a meta tag with name and content
     * @param $name string
     * @param $content string
     */
    function set_meta_tag($name, $content)
    {
        $this->tags->$name = $content;
    }
    
    /**
     * Removes a meta tag
     * @param $name string name of the tag
     */
    function unset_meta_tag($name)
    {
        unset($this->tags->$name);
    }
    
    /**
     * Adds a unit to the keyword array
     * @param $keyword string
     */
    function add_keyword($keyword)
    {
        $this->remove_keyword($keyword);
        $this->keywords[] = $keyword;
    }
    
    /**
     * Searches the keywords array and removes the given keyword
     * @param $keyword string
     */
    function remove_keyword($keyword)
    {
        $this->_search_and_remove($keyword, $this->tags);
    }
    
    /**
     * Adds a rule to the robots array
     * @param $rule string
     */
    function add_robots_rule($rule)
    {
        $this->remove_robots_rule($rule);
        $this->robots[] = $rule;
    }
    
    /**
     * Searches the robots array and removes the given rule
     * @param $rule string
     */
    function remove_robots_rule($rule)
    {
        $this->_search_and_remove($rule, $this->robots);
    }
    
    /**
     * Library-only function for searching and removing
     * @param $needle string
     * @param $haystack array
     */
    function _search_and_remove($needle, $haystack)
    {
        $key = array_search($needle, $haystack);
        if($key)
        {
            unset($haystack[$key]);
        }
    }
    
    /**
     * Passes the contained data to private functions for processing
     * @return string the compiled meta tags for insertion into your view
     */
    function generate_meta_tags()
    {
        switch(strtolower($this->doctype))
        {
            case 'xhtml':
                $output = $this->_generate_xhtml_meta_tags();
                break;
            case 'html':
                $output = $this->_generate_html_meta_tags();
                break;
        }
        return $output;
    }
    
    /**
     * Generates meta tags following the XHTML conventions
     * @return string the compiled meta tags for insertion into your view
     */
    function _generate_xhtml_meta_tags()
    {
        $output = "\n";
        
        if(!empty($this->tags))
        {
            foreach($this->tags as $name=>$content)
            {
                $output .= '&lt;meta name="'.$name.'" content="'.$content.'" /&gt;'."\n";
            }
        }
        
        if(!empty($this->keywords))
            $output .= '&lt;meta name="keywords" content="'.implode(',', $this-&gt;keywords).'" />'."\n";
        
        if(!empty($this->robots))
            $output .= '&lt;meta name="robots" content="'.implode(',', $this-&gt;robots).'" />'."\n";
        
        return $output;
    }
    
    /**
     * Generates meta tags following the HTML conventions
     * @return string the compiled meta tags for insertion into your view
     */    
    function _generate_html_meta_tags()
    {
        $output = "\n";
        
        if(!empty($this->tags))
        {
            foreach($this->tags as $name=>$content)
            {
                $output .= '&lt;META NAME="'.$name.'" CONTENT="'.$content.'"&gt;'."\n";
            }
        }
        
        if(!empty($this->keywords))
            $output .= '&lt;META NAME="keywords" CONTENT="'.implode(',', $this-&gt;keywords).'">'."\n";
        
        if(!empty($this->robots))
            $output .= '&lt;META NAME="robots" CONTENT="'.implode(',', $this-&gt;robots).'">'."\n";
        
        return $output;
    }
    
}

/* End of file meta_tags.php */
/* Location: ./system/application/libraries/meta_tags.php */