Some time ago I started working on the screen widget thread safety.
There were many places in code where widget models were being modified
during rendering - resulting in unpredictable behavior, and in some
cases it resulted in users having access to data they shouldn't be able
to see.
While doing that work, I was overwhelmed by the quantity of source code.
The screen widget library was built using a lot of copy-and-paste -
instead of extracting and reusing common things. Scott started working
on reusing widget code, but that was just a small beginning.
In a recent commit, I continued his work and made some more things reusable.
Next, I would like to reorganize the source code folder structure. Here
is what I have pictured:
org/ofbiz/widget
artifact (Artifact Info classes)
cache (Widget cache classes)
model (Widget models)
renderer (Widget renderers)
macro
html
xml
I think the simplified folder structure makes more sense and it will
make it easier to locate classes.
After that, I would like to add error checking code to the widget models
- similar to what I did in Mini-Language. Right now, errors in widget
XML are (sometimes) logged and widget parsing continues. If a developer
does something wrong, they will not know it unless they check the logs.
I would like to change the behavior so widget XML errors throw an
exception with a detailed error message that includes the XML file name
and line number where the error occurred. I believe this will benefit
developers by making it clear when they have done something wrong.
Finally, I would like to extract list functionality from the form widget
and create a new grid widget. So, instead of a form widget representing
a single data entry form OR a list, it will ONLY represent a single
form. If you want a list, you use the grid widget. Initially, this
change will be backwards-compatible - the XML parser will accept a
<form> element for both types and it will create the correct model based
on the type attribute.
Overall, my goal is to make screen widgets more developer-friendly, and
also to make it easier to innovate in the screen widget component.
After all of this work is completed, I would like to backport it to the
R14 branch.
Comments are welcome.
--
Adrian Crum
Sandglass Software
www.sandglass-software.com
