PHP：模拟函数内未知变量的全局行为

Question

To include raw JavaScript files into my pages, i've ended up using:

function include_js($jsfile, $basepath = JSPATH){
    echo '<script type="text/javascript">';
    include($basepath . $jsfile);
    echo '</script>';
}

Works fine, and the PHP code inside these JS files is still executing fine, no problem here. But here is some pseudo code of what i used before:

<script>
    var hello = '<?php echo $id; ?>';
</script>

So, here's the problem:

• Before, the PHP code used inside my JavaScript files was executed in the same context as the page's one.
• Now, it's executed in the context of the include_js() function.

Thus, i don't have access to any of my page's variables anymore. I could fix it with a global $id;, but that was pseudo-code.

Actually, i have NO idea what variables i'll need to have access to.

Any idea how to solve that problem? If you have a better solution than what i'm actually doing inside include_js() to achieve the same goal without the problem i'm talking about, that would be as much appreciated!

Answer 1

You could import all global variables (but Superglobals) into the local scope of the function where you do the include. I don't think it's really a good solution (as it's a hammer) but as you write in your question you don't know which variables are used, so you could localize them like:

$varname = $GLOBALS['varname'];

As an alternative you could inspect the JS file and/or provide the list of variables for a file and add it to the include function as an array. See another answer for some code example.

You could also first pre-include (and throw away) the js file, gather the warnings about undefined variables, import them and then include for real. Some more include/discard/return/variable related chunks of code.