How does this module compare to http://drupal.org/project/dependent ?
Their aim seems to be similar :)
Also wondering the same...
Also posted at http://drupal.org/node/288912#comment-942181 - it might be beneficial to all if you joined forces?
I've tested Dependent Field: it's very similar to conditional fields, with less options. If you don't need multiple values and fieldgroup support, dependent fields may be better for you.
A little more detail ...
1. Conditional fields supports fieldsets (groups) which is nice if you have several fields that depend on the same option
2. Conditional fields displays all of the possible parent fields as select list with the values as the options instead of putting all fieldname / options in one list
So dependent is more consice, but conditional field is easier to look at
3. Dependent doesn't support groups so if all of the fields in a group are hidden you still see the empty group. That said, conditional fields doesn't let you put a field in a group if has a conditional parent. You have to unset the conditional parent before you can move the field. I can see either approach being advantageous based on the use case.
4. Dependent does pretty j-query sliding, Conditional Fields just instantly shows or hides the fields
5. I believe both allow multiple conditional parents, and there is a patch to make dependent support key|value options
And last but not least it appears that dependent is currently more active being developed.
When in doubt try both.
One is for Drupal 6.x and other is for Drupal 5.x.
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