Using a Template Processor Class in PHP 5 - Getting started using the “TemplateProcessor” class: a quick look at its definition
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Before I proceed to demonstrate how to use the “TemplateProcessor” class, I need to remind you of how it looks, so it can be fresh in your mind. That said, here’s the corresponding definition for the class, as I wrote it originally in the first article:
// define 'TemplateProcessor' class
class TemplateProcessor {
private $output='';// set default value for general class
output
private $rowTag='p';// set default value for database row tag
private $tags=array();// set default value for tags
private $templateFile='default_template.htm';// set default
value for template file
private $cacheFile='default_cache.txt';// set default value
for cache file
private $expiry=10;// set default value for cache expiration
public function __construct($tags=array()){
if(count($tags)<1){
throw new Exception('Invalid number of tags');
}
if($this->isCacheValid()){
// read data from cache file
$this->output=$this->readCache();
}
else{
$this->tags=$tags;
// read template file
$this->output=file_get_contents($this->templateFile);
// process template file
$this->processTemplate($this->tags);
// clean up empty tags
$this->output=preg_replace("/{w}|}/",'',$this-
>output);
// write compressed data to cache file
$this->writeCache();
}
// send gzip encoding http header
$this->sendEncodingHeader();
}
// check cache validity
private function isCacheValid(){
// determine if cache file is valid or not
if(file_exists($this->cacheFile)&&filemtime($this-
>cacheFile)>(time()-$this->expiry)){
return true;
}
return false;
}
// process template file
private function processTemplate($tags){
foreach($tags as $tag=>$data){
// if data is array, traverse recursive array of tags
if(is_array($data)){
$this->output=preg_replace("/{$tag/",'',$this-
>output);
$this->processTemplate($data);
}
// if data is a file, fetch processed file
elseif(file_exists($data)){
$data=$this->processFile($data);
}
// if data is a MySQL result set, obtain a formatted
list of database rows
elseif(@get_resource_type($data)=='mysql result'){
$rows='';
while($row=mysql_fetch_row($data)){
$cols='';
foreach($row as $col){
$cols.=' '.$col.' ';
}
$rows.='<'.$this-
>rowTag.'>'.$cols.'</'.$this->rowTag.'>';
}
$data=$rows;
}
// if data contains the '[code]' elimiter, parse data
as PHP code
elseif(substr($data,0,6)=='[code]'){
$data=eval(substr($data,6));
}
$this->output=str_replace('{'.$tag.'}',$data,$this-
>output);
}
}
// process input file
private function processFile($file){
ob_start();
include($file);
$contents=ob_get_contents();
ob_end_clean();
return $contents;
}
// write compressed data to cache file
private function writeCache(){
if(!$fp=fopen($this->cacheFile,'w')){
throw new Exception('Error writing data to cache
file');
}
fwrite($fp,$this->getCompressedHTML());
fclose($fp);
}
// read compressed data from cache file
private function readCache(){
if(!$cacheContents=file_get_contents($this->cacheFile)){
throw new Exception('Error reading data from cache
file');
}
return $cacheContents;
}
// return overall output
public function getHTML(){
return $this->output;
}
// return compressed output
private function getCompressedHTML(){
// check if browser supports gzip encoding
if(strstr($_SERVER['HTTP_ACCEPT_ENCODING'],'gzip')){
// start output buffer
ob_start();
// echo page contents to output buffer
echo $this->output;
// crunch (X)HTML content & compress it with gzip
$this->output=gzencode(preg_replace("/
(rn|n)/","",ob_get_contents()),9);
// clean up output buffer
ob_end_clean();
// return compressed (X)HTML content
return $this->output;
}
return false;
}
// send gzip encoding http header
public function sendEncodingHeader(){
header('Content-Encoding: gzip');
}
}
I suppose at this point, after listing the “TemplateProcessor” class, you’re ready to see an illustrative hands-on example, in order to learn how you can use it for parsing your template files. Want to learn how this will be achieved? Please, read the next few lines.
Next: Parsing template files: defining the input tags for the “TemplateProcessor” class >>
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