[newforms-admin] prepopulated_fields results in javascript error (None is not defined)

[forest@…]

I get this in Firefox 2:

Error: None is not defined
Source File: http://localhost:8080/admin/page/section/add/
Line: 142

The javascript source is as follows:

<script type="text/javascript">

    document.getElementById("id_slug").onchange = function() { this._changed = true; };
    
    document.getElementById("id_title").onkeyup = function() {
        var e = document.getElementById("id_slug");
        if (!e._changed) { e.value = URLify(document.getElementById("id_title").value, None); }
    }
    

</script>

-Forest

[Brian Rosner <brosner@…>]

I came across this problem as well. I spent a little bit of time looking through the source to find the root of this problem.

In django/contrib/admin/templates/admin/change_form.html the line that causes the problem is (line 87 as of r5499):

if (!e._changed) { e.value = URLify({% for innerdep in field.dependencies %}document.getElementById("{{ innerdep.auto_id }}").value{% if not forloop.last %} + ' ' + {% endif %}{% endfor %}, {{ field.field.field.max_length }}); }

The call to {{ field.field.field.max_length }} results in None. This is due to maxlength from the model not being push through to the formfield created by the model Field class. This may also be be field independent, but since pre_populated uses CharFields, it would be more specific to that.

I guess the real question is, should maxlength be pushed over to the form field? I would it should, but perhaps some people will confuse that with an enforcement of that number in the actual form field. I don't know. ;) If it is as simple to move it over, I'd be up for writing a patch to fix that.

[Brian Rosner <brosner@…>]

I stand corrected. My comments above should really be disregraded. I looked at this a little more in depth and it turns out this is a problem with the SlugField field implmentation. It subclasses Field and doesn't have a formfield method which Field's formfield method does not push over maxlength. If you subclass SlugField with CharField the problem is solved.

[Brian Rosner <brosner@…>]

patch to fix #4174

[anonymous]

Works fine for me, thanks for the patch.

[Brian Rosner <brosner@…>]

I believe this has been fixed as of r5926 in newforms-admin. Russell can you comment on this? If so, this ticket can be closed.

[Brian Rosner <brosner@…>]

Err, ignore my comment above, this is the wrong ticket ;)

[nirvdrum]

I can also verify that the patch does work.

[Adrian Holovaty]

Fixed formatting in description.

[jkocherhans]

Doh! Sorry, I fixed this earlier tonight, completely forgot to look at the discussion here, and came to the same conclusions. That would have saved a few minutes of my life :) Fixed in [6056]

[Brian Rosner <brosner@…>]

Hey, thanks for the credit ;) It looks like this ticket should be a duplicate of #3557. r6065 looks like to solve both.