Sunday, April 8, 2012

JQuery Templates - too much recursion



I am using jquery templates to generate a tree structure to later display as a treeview of sections and items.





The structure of data looks like this, where each section has items and sections and each item can have more sections:







section

items

item

sections

item

sections

sections

section

sections

items



...and so on







My templates then recursively call each other:







<script id="my-item-tmpl" type="text/x-jquery-tmpl">

<li>

<span>${text}</span>

<ul>

{{each sections}}

{{tmpl($value) "sectionTmpl"}}

{{/each}}

</ul>

</li>

</script>



<script id="my-section-tmpl" type="text/x-jquery-tmpl">

<li>

<span>${text}</span>

<ul>

{{each items}}

{{tmpl($value) "itemTmpl"}}

{{/each}}



{{each sections}}

{{tmpl($value) "sectionTmpl"}}

{{/each}}

</ul>

</li>

</script>









$("#my-item-tmpl").template('itemTmpl');

$("#my-section-tmpl").template('sectionTmpl');





$.tmpl('sectionTmpl', { section }).appendTo(this);







I am finding however with around 4 levels into the structure I receive a "too much recursion " error in my console.





Is this just a limitation of the jQuery Template engine?





Edit:





I've resolved this by removing the {{each}} and replacing it with a {{tmpl}} call. The {{each}} was not needed. I have also wrapped each {{tmpl}} call in an {{if}} to ensure the collection exists.



Source: Tips4all

1 comment:

  1. Javascript has a recursion limit of about 1000 levels; with the structure you're using you probably shouldn't be hitting that, though.

    "My templates then recursively call each other"

    The markup makes my head hurt, so I'm having some difficulty reading the code (my problem, not yours), but any time I've hit the stack limit on recursion for anything, it has either been because I'm intentionally stressing something with deep recursion, or because I've got a circular reference somewhere so that my recursion never terminates.

    So, in general: make sure there's a way for your function to complete, instead of creating new instances of itself forever.

    ReplyDelete