Replace Tags with Our Data - XML

Let’s play tag:

As you can see the XML document contains three main elements, header, body, and footer. With in each of those we have the basic three column page layout, and a few proprietary tags such as <!title> and <!logo>. These are going to be the elements that we’re going to replace with our own non-template data. So first things first, we need to figure out how to replace the tags with our data. I created the following function to do so.

function replace($load,$string,$mask='<!-tag->'){
        if(!is_array($load)){
            return $string;
        }else{
            if(!strpos($load,'-tag-')) $mask='<!-tag->';
            $masks=explode('-tag-',$mask);
            $tags=array_keys($load);
            foreach($tags as $tag){ 
                $newtags[]=$masks[0].$tag.$masks[1];
            }
            $loads=array_values($load);
            return str_replace($newtags,$loads,$string);
        }
    }

Before we go any farther, lets take a look at this function so you know exactly what it does.

First we define the function and all the parameters it will accept:

• $load is the array of tags we’re going to replace, the array should be set up like this array(‘tagname’=>”data to place where the tag is”)
  
• $string is the variable that holds the XML string that we’ll later get from simpleXML
  
• $mask is an optional variable that you can use incase you want to use a different tag style, such as <*tag> function replace($load,$string,$mask='<!-tag->'){

Then we make sure that $load is an array so that we don’t get any nasty unexpected errors. If it’s not an array the function will just return the XML string without processing it

if(!is_array($load)){
            return $string;
}

If $load is an array, we first make sure that there isn’t a tag in the $load named “-tag-“(1). Then we explode the $mask tag by “-tag-“ so that we have an array that has the opening and closing brackets for each tag, “<!” and  “>”(2). Now you might say “why all this stuff about the tags being explode to simply get the ‘<!’ and ’>’.” The reason behind that is so that you can change the tag style to something else like <*-tag-> if you want.

(1) if(!strpos($load,'-tag-')) $mask='<!-tag->';
(2) $masks=explode('-tag-',$mask);

Now we’re about to use a built-in PHP function that isn’t used too often but is very useful, array_keys(). array_keys() returns the keys of the input array as the values of the output array consider the following.

$array1 = array('key1'=>"value1",'key2'=>"value2");
$array2 = array_keys($array1);
print_r($array2);

This will output:

Array
(
    [0] => key1
    [1] => key2
)

Pretty cool and useful isn’t it.