category-driven dependent selects

[Nick S.]

I have a custom Article content type. I would like to use the built-in
categorization in FarCry as a way to apply a Category and sub-category
to the content. Is there a way to implement a dependent select so that
the user must first a Category from a drop-down and then a separate
list box will be populated with the sub-categories to select from?

I'm currently using form tools and I'm not sure how to further
customize the form to allow for this type of interaction. Let me know
if this is a possibility, I can't seem to find this functionality
either in the wiki or mailing list.

Thanks in advance,

[Blair McKenzie]

What version of FarCry are you using?

[nicholas sollecito]

5.1

[Blair McKenzie]

You can have the first item by using ftType="category", ftAlias="parentcategoryalias" and ftRenderType="dropdown" (I think).

For the second one, you will probably need to write a custom formtool code.

Two approaches.

ONCE OFF CUSTOMISATION
1) Add a function named like ftEditYourSecondaryProperty to the custom type. Open up core/packages/formtools/category.cfc and copy the arguments and code from the edit function into yours.
2) Look for where ftAlias is param'd / used, and change the code so that the value of the primary property is used instead
3) In the cfproperty definition, add ftWatch="primarypropertyname". This will add ajax to the form that updates the field when the primary property changes.

REUSABLE SUB-CATEGORISATION
1) Extend formtools/category.cfc in your project to secondarycategory.cfc (or whatever)
2) Copy the edit function from category.cfc to your formtool
3) Param another metadata attribute ftPrimaryCategory. Set ftAlias to the value of that attribute.
4) In the cfproperty definition, set ftType="secondarycategory"
5) Add ftWatch="primarypropertyname". This will add ajax to the form that updates the field when the primary property changes.

[nicholas sollecito]

Ok, so I've followed most of your directions, but I think I'm still missing something. Here's what I've done so far...

I've set up the cfproperty for the primary category select as instructed. 

For the secondary category, I've taken the "reusable sub-categorisation" approach. I've successfully created the secondaryCategory.cfc which extends farcry.core.packages.formtools.category. I've copied the edit() method and was able to verify through cfdebugging that this is being used for rendering the secondary category property.

Now, here's where I'm confused. First, I've added the ftPrimaryCategory key to the param'd metadata. 

Next, when you say "Set ftAlias to the value of that attribute" I'm not sure exactly where you are referring to. By ftAlias, do you mean the other metadata params in the edit method (as in arguments.metadata.ftAlias)? Or, is this the ftAlias attribute in the cfproperty for the secondary category definition? I've added ftWatch to the cfproperty with the name of the primary dropdown property.

Also, this may or may not have anything to do with anything, but...

I've been digging through the formtools code as well as the wiki to try and figure this out on my own, but I don't seem to really be getting anywhere... It looks like the ajax dependency selects is implemented via farcry.core.packages.formtools.field.addWatch(). So, I searched all the files to see where addWatch() is being called. Other than a recursive call in the method itself, it looks like it's being called only from the object.cfm formtools tag. I set up a trace to see how this was being called from my custom type and it doesn't appear anywhere. I checked some other types and see that it is being called (except from News, which my type is based upon). Wonder if this could be one reason why I'm having problems?

Also, I'm looking to just grab just one level of categories. Currently, based on the structure below, if I set ftAlias="content" the dropdown contains all categories below it. I would like to just get the items at the first level beneath "Content". Once a primary is selected, my secondary category dropdown would then be populated with the level 3 categories.

root

- Content

-- Magazine Title 1 (primary)

--- Column 1 (secondary)

--- Column 2

...

-- Magazine Title 2

--- Column 3

--- Column 4

...

Anyway, I hope this is clear. Thank you so much for helping with this, I'm pretty new to FarCry but so far I'm very impressed with the potential

-Nick

[Blair McKenzie]

ftAlias is used by category.cfc (and your own formtool) to specify which category branch to use. It looks for the specified alias (obviously). This part of the edit function needs to be changed so that instead of looking for the branch named with ftAlias, it looks for the branch specified in arguments.stObject[arguments.stMetadata.ftPrimaryCategory] (I think) which will be the uuid of the parent category.

It looks like you will have to create a primarycategory formtool as well if you want a single level list. To retrieve a single level inside the formtool use
application.factory.oTree.getChildren(objectid=parentid)
instead of the original
oCategory.getCategoryBranchAsList(lCategoryIDs=rootID)
This will return a query of objectid,objectname instead of a list of objectid.

The default ajax stuff is added with the ft:object tag. It basically adds events to the watched fields. If those other fields change, the dependent field is ajax'd in. Basically the edit function gets called with the new watched values passed in. You can see an example of this at work with the country and state formtools. Neither of them mention ajax, and both work without it. But if you add ftWatch="countryproperty" to the state property the state list starts automagically switching when the country is changed.

[Tomek Kott]

hot-damn! This is making me want to push up my schedule for switching to 5.1 from 5.0! Didn't realize changes like this had made it in. Great work!

I have one question about implementation possibility:

If I have a drop down list for choices (say profession) where I have some general options, but want an "other". If someone chooses other, I'd like a text field to appear (say its generally a hidden property in the form tool). Is this functionality extendible in a similar way you described above to change ftType from hidden to text?

Thanks!

Tomek

[nicholas sollecito]

Ok, I think I'm finally getting somewhere with this. No matter what I tried, I couldn't get any of the Ajax functions for the dependent selects to be generated in my Edit form. 

So, using the sample cfproperty definitions for Country/State from the wiki, I created a dummy custom type to get an idea of what mine was missing. I noticed the javascript listener was being generated for Country/State, but not for my custom type. I realized the reason for this is that I have a mult-step wizard, so the tag library being used to do the formtools magic is in farcry/core/tags/wizard. So, instead of ft:object being called where addWatch() is executed, wiz:object was being called, where there is no reference to addWatch and therefore, none of the Ajax goodness was included. 

I simply copied the addWatch call from farcry/core/tags/formtools/object.cfm (line @452) to farcry/core/tags/wizard/object.cfm (line @387) and I'm now getting the proper javascript listeners as well as dynamic select functionality added in. Still need to refine to grab the level of categories I need, but this MAJOR piece of the puzzle is now in place to help me finish this up..

Now, this has resulted in me having to make a change to the actual core farcry tag files which I understand is not ideal... How do I ensure that this change makes it into the core source (or, if there is a reason it's not there already, how do I maintain my version of it?).

Thanks again for your help. 

[Blair McKenzie]

@Tomek Yes, you could do that. Its simple to create a formtool edit handler that outputs different html depending on the values in arguments.stObject. ftWatch is basically just a way of AJAXifying that dependency.

@nicholas No, no - thank you! I completely forgot to add it to the wizard version. I think there's a ticket for that issue now - could you attach your updated file to the ticket so we can include it in the 5.1 release?

[nicholas sollecito]

Hi Blaire,

Is this the ticket you're referring to? http://bugs.farcrycms.org/browse/FC-1737

Looks like it has been resolved already... wouldn't you know, the very day I downloaded the 5.1 install :-P

Thanks again,

-Nick

[Blair McKenzie]

Haha. That's the one.