using PHP in external JS

Question

I have a big validation JS script. I want to put this script to be external JS.

Everything works fine with this, but in the JS i use cookie to handle the my user form junctions.

And besides, i use PHP in this JS.

If the JS in the html, then works. But if i put it to external, then no.

For example:

External JS:

$(document).ready(function() {

     var test = $.cookie('tet');
     $.cookie('tet','8'); 

    <?php
     if (isset($_SESSION['main_check_a'])) {
     echo "$.cookie('tet','1');";
    ?>
}}

}

How can i pass this PHP code to my external JS?

Pekka · Accepted Answer · 2010-10-05T09:35:30.253

5

You need to either

Have the JS file parsed by PHP, by naming it filename.js.php or by changing the server's configuration for PHP to parse .js files. This is not optimal however, because a resource-intensive PHP instance will be started for every script request.
Alternatively, much better IMO, do the necessary checks in a <script> tag in the embedding document, and store the results in JS variables that the embedded external scripts can query. This way, your script files can stay static.

In your case, this would mean something like this. In the main document:
```
<script> 
<?php 
   echo "main_check_a = "; 
   echo (isset($_SESSION['main_check_a']) ? "true" : "false"); 
 ?>
</script>


.... now, include external JS files ....
```
this will give you the JavaScript variable main_check_a that you can use in your external scripts.

edited Oct 05 '10 at 09:35

answered Oct 05 '10 at 09:20

Pekka

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You could also do it the other way round: include but do not run the external code yet. Then instantiate/execute with the needed code from a local script block. That would be DI instead of using globals ;) But in any way, separating the PHP from the external JS is the best way. – Gordon Oct 05 '10 at 09:40
now..i try your 2nd suggested..but...at now..i dont really understand:) – holian Oct 05 '10 at 09:45
@holian the basic idea is to do all the dynamic stuff (everything PHP needs to run for) in the document, as shown in the code snippet above. The snippet stores the PHP action's result in a Javascript variable that you can use in your external JS. It's hard to give more detail than that :) What @Gordon (correctly) suggests is an even more advanced and cleaner way to do the same thing, but that is very advanced and may need some rewriting of your code. If you're struggling to get it to work at all, I'd focus on making it work using variables first. – Pekka Oct 05 '10 at 09:52
ok..after the page load, i see the source, and main_check_a variable is get the value...its ok..but in the JS something wrong, 'coz never get inside to the condition (the value is true, im sure) if (main_check_a == "true") { $.cookie('tet','1'); alert('inside'); }; – holian Oct 05 '10 at 10:01
@holian that is really a debugging question. In your case, you probably need to drop the quotes around the "true" - look closely at the code that gets generated – Pekka Oct 05 '10 at 10:11
Second alternative for the win. – erlando Oct 05 '10 at 13:19

score 3 · Answer 2 · answered Oct 05 '10 at 09:20

3

You have to setup the server to parse this file. Ususally you would give it the extension *.php

To avoid particular problems you should send a correct header inside this script:

header('Content-Type:text/javascript');

If you cannot change the extension, you can e.g. use Apache's AddType-Directive to setup the server to parse *.js-Files(but i would'nt recommend it)

answered Oct 05 '10 at 09:20

Dr.Molle

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same as Matt's: kills caching – Gordon Oct 05 '10 at 09:44
1

That's right. It would be better to provide the needed serverside variable inside the document and only use non-dynamic JS as external ressource. Or if the dynamic part of the script contains more than just a variable, it's better to split them into dynamic and static parts. – Dr.Molle Oct 05 '10 at 09:51

score 2 · Answer 3 · answered Oct 05 '10 at 09:44

If you're experimenting with php/js codegeneration, stop right now. It's what I'd call a 'high risk' practise as it blurs the line between business and view logic. Furthermore you end up with a hard to maintain code soup and browser cache headaches.

Code generation should be avoided at all times unless there's a good reason for it and I wouldn't call cookie handling a good reason. With a bit more thought, you can come up with a better more maintainable solution.

Deal with business logic cookies along the lines of 'can I' and 'May I'. In other words; if there's a reason to write a cookie with PHP, keep it in PHP and only read cookies with JavaScript.

Also, you want your JavaScript files to remain static files, or it won't do what you expect it to do due to browser caching and you have to employ more hacks to prevent the browser from caching the files.

In the end, it was less work to do it the right way all along.

score 2 · Answer 4 · answered Oct 05 '10 at 09:45

Keep in mind that your visitors will have to download the generated JavaScript everytime they visit your site, as browsers won't cache it.

If I were you I would consider redesigning the whole thing so that you don't need a PHP generated JavaScript in the first place.

score 1 · Answer 5 · answered Oct 05 '10 at 09:19

1

Either configure PHP to parse .js files, or name your external JavaScript file /yourjavascriptfile.js.php

answered Oct 05 '10 at 09:19

Matt

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it should be noted that this also means the file will no longer be cached without additional measures. – Gordon Oct 05 '10 at 09:43

using PHP in external JS

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