Last piece of the pie! javascript no longer works after page.replace_html

Hi there,

I have one last remaining problem to solve before I'm code complete on an application I've been working on for a few months, and I need your help.

I have a page that contains a list of entries and a form at the top that uses form_remote_tag to allow users to add new entries via AJAX. When the user submits the form, the list of entries is updated from the controller using render :update and the same partial that was used to initially render the page. The entries in the list are draggable, at least they are BEFORE the entry list is updated as a result of AJAX call.

After the AJAX call is complete, the list entries are no longer draggable. I am using jQuery and Prototype, jQuery for the drag and drop. The javascript drag and drop code is in my application.js file. If i move the javascript in-line into the partial that generates the list of entries, after a form submit, the entries are still draggable, but that has its own set of problems and i don't want to do that.

Why would the drag and drop no longer work after the AJAX call when I'm using the same partial that was used to render the page when all the drag and drop javascript is in the application.js?

I tried as an alternate solution using :update as part of the form_remote_tag in the view but that didn't work either.

Any help solving this last problem would be greatly appreciated.

Regards, -A

Presumably when you load the page the first time round, some sort of initialisation occurs that marks the elements as draggable (ie installs various event handlers and what not). When you replace the list, you would need to do that initialisation on the new dom elements.

Fred

Good point. Right now, the jQuery drag and drop javascript code is not inside a function in application.js. I'm not all that experienced with Javascript. Would i need to wrap the drag and drop code inside a function that's called when the partial is displayed to re-initialize the event handlers etc? Can you give me an example of how to do that? I'm happy to post my drag-and-drop javascript code if that will help.

Thanks Fred, -A

Good point. Right now, the jQuery drag and drop javascript code is not inside a function in application.js. I'm not all that experienced with Javascript. Would i need to wrap the drag and drop code inside a function that's called when the partial is displayed to re-initialize the event handlers etc?

Something like that. Exactly what goes where is likely to depend on what your drag and drop code looks like.

Can you give me an example of how to do that? I'm happy to post my drag-and-drop javascript code if that will help.

form_remote_tag etc... take a bunch of options, in particular :success is a javascript fragment that is evaluated when the ajax call has succeeded. In this case it should probably do whatever initialization you need to make things work

Fred

Thanks Fred, here's what I got...

My application.js file looks like this (below is the drag and drop code)...

  jQuery(document).ready(function(){     jQuery(".block").draggable({     helper: 'clone',     revert: true});   jQuery(".drop").droppable({     accept: ".block",     tolerance: "pointer",     activeClass: 'droppable-active',     hoverClass: 'droppable-hover',     drop: function(ev, ui) {       var entryID = jQuery(ui.draggable).attr("id").replace('entry_','');       var dropCategoryID = jQuery(this).attr("id").replace('category_','');       var origCategoryID = jQuery('#current_category_' + entryID).attr("class");       var categoryColor = jQuery(this).attr("style").replace('background: ','');       var dropCatCount = jQuery('#category_' + dropCategoryID + ' span:first').html()       var origCatCount = jQuery('#category_' + origCategoryID + ' span:first').html()       if (dropCategoryID != origCategoryID) {         if (origCategoryID == 'none') {           dropCatCount++           jQuery('#category_' + dropCategoryID + ' span:first').html(dropCatCount)         }         else {           dropCatCount++           origCatCount--           jQuery('#category_' + dropCategoryID + ' span:first').html(dropCatCount)           jQuery('#category_' + origCategoryID + ' span:first').html(origCatCount)           jQuery('#current_category_' + entryID).removeClass(origCategoryID).addClass(dropCategoryID)           /* you need to update the origCategoryID */         }       }       /* this deals with FireFox */       var testHex = /[\#]/.test(categoryColor)       if (testHex == false) {         categoryColor = RGBToHex(categoryColor);       }       jQuery('#entry_cat_' + entryID).css("background-color", categoryColor);       jQuery.ajaxSetup({         data: { authenticity_token : AUTH_TOKEN }       })       jQuery.ajax({         type: "POST",         url: ("entries/entry_categorize?entry=" + entryID + "&category=" + dropCategoryID),         dataType: "script"       })     }     });   });

In my view, my form_remote_tag code looks like this...

  <% form_remote_tag(:url => {:id => current_user.id},                 :html => {:name => 'new_entry_form'},                 :update => 'user_entries',                 :complete => "reset('new_entry_form')"                 ) do %>

I tried wrapping the drag and drop code that i pasted above which lives in application.js inside a function named initiateDragDrop, but as I said, my javascript isn't strong, so I'm not sure that I did it correctly. I then added ":success => "initiateDragDrop()" to my form_remote_tag expecting that the drag and drop would work after I posted the form, but it didn't.

What am i doing wrong?

Thanks, -A