How to make a general form in Flex to deal with Entity CRUD?

Question

I would like to create a general form so that it can deal with creation/read/update of an entity. When creating an entity, it may only contain a subset of all fields; when updating the entity, it may contain a different subset of fields; and when reading the entity, none of the fields are editable. Anyone with experience in designing such a form in Flex? Thanks in advance.

Answer 1

I was frustrated with the quality of the flex forms as well, especially managing the validation, so I wrote my own form control. It's a bit haphazard and buggy at times so it's not ready for sharing, but I'll cover the ideas:

1. Separated into a layout part and a data part, matched by keys. Both are basically combinations of AS3 Objects/Arrays containing the properties I need.
2. Describe all the possible visible elements in the layout, the validators needed, visual properties, labels ,etc... Every element in the layout is an Object in an Array. The primary array is ordered and displayed via a VBox. Any nested arrays are displayed in a nested HBox (e.g., useful for radio options).

3. The data part of the form is where you can set initial values, "editable" properties, "model" properties (for combo boxes), things like that. The data structure is an Object hash where the keys map to elements in the layout. If an entry from the layout does not exist in the data definition, it does not appear. This allows you to easily hide sections you don't want to show.

4. Has an errors sections where validation or server errors can be displayed.

5. Has a collect function that collects all the data into an object hash.

6. Has a validate function to control when the validators are triggered.

7. Non editable fields show up as labels.

8. Basically I've implemented my own "Form" control, and each entry in the layout (when displayed) becomes a custom "FormItem" control that will be whatever type the layout described. ("text","combo","heading",...)

Hard to describe without visual examples and some code, but that's the basic idea. You're on the right track thinking that you need your own control. There's too much hand-holding required for the generic forms, and lots of redundant code.