Passing PHP Values to Javascript

3 Posts

TheFoot Reply #1, 17 years, 2 months ago

Hi.

Just started with MODx.. and need a little help converting my existing template structure into MODx..

I have PHP objects that setup things like resource caching etc. Quite often in my existing template, I use JS code such as:

CLIENT_OBJECT.image_cache = <?php echo SERVER_OBJECT.getImagesArrayForCaching(); ?>;

.. to write PHP values and objects directly into Javascript objects.

I cannot figure out how to do this in MODx - Chunks cannot contain PHP and a snippet with the above code in simply doesn’t work.

Where am I going wrong? Are snippets and chunks even the mechanism that I need to use to achieve this?

TIA

TheFoot

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24,524 Posts

sottwell Reply #2, 17 years, 2 months ago

You can use a snippet in your javascript just as you would have used <?php ... > tags. If echo doesn’t do what you expect, try using return instead.

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46 Posts

Aikdo Reply #3, 17 years, 2 months ago

You would need to create a snipit say we call it

Caching - With the php code in it like :-

<?php echo SERVER_OBJECT.getImagesArrayForCaching(); ?>

Then in the page you would have the script

CLIENT_OBJECT.image_cache = [[Caching]];

though that is in evolution in revolution the snippet call would be different.

3 Posts

TheFoot Reply #4, 17 years, 2 months ago

Thanks for your posts...

I still cannot get it to work. The following is in a snippet called [[header]]:

<?php
session_start();
	include_once('assets/include/server/thefoot.php');		
	
	// Page initialisation
	$v_error_msg = "";
	$THEFOOT->init(); // This function populates a string property with a JSON array
?>

Here is the snippet that I use [[js-cache-images]], to get at the images array:

<?php
echo $THEFOOT->json_images;
?>

In my page template, the first line contains the header snippet call [[header]], then in the <HEAD> javascript section I have:

                // Prime the image cache 
		THEFOOT.o_cache_images = [[js-image-cache]];

Nothing is output from the snippet. I have tried return and echo. However, if I output a constant string such as:

<?php
echo "{\"images\": []}";
?>

.. then it works fine.

In the [[header]] snippet, I output (echo’d) the result of the $THEFOOT->json_images, and I know that the script executes and populates the array. It seems to get lost between the 2 snippet calls. Any ideas?

Thanks, TheFoot

5,888 Posts

Bruno17 Reply #5, 17 years, 2 months ago

you can try it with modx-placeholders:

<?php
session_start();
	include_once('assets/include/server/thefoot.php');		
	
	// Page initialisation
	$v_error_msg = "";
	$THEFOOT->init(); // This function populates a string property with a JSON array

        $modx->setPlaceholder('jsImageCache',$THEFOOT->json_images);

?>

                // Prime the image cache 
		THEFOOT.o_cache_images = [+jsImageCache+];

-------------------------------

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Thanks!

3 Posts

TheFoot Reply #6, 17 years, 2 months ago

Brilliant! grin

Works perfectly - thanks....