Remove Automatic Component Bindings

The last couple of day I spend some time investigating the ‘Automatic Component Binding’ feature. A code review I did lately showed that about 40% of the jspx pages of one project (about 60 pages in total) had automatic component binding on. As each page thus have a bean defined where the ui components are bound to, the project also contains a lot of beans. The beans are generated automatically and in this case don’t do anything but eat memory.

So two questions came up:
1) Why where automatic component binding on in so many pages, as we don’t use this feature?
2) How to get rid of the bindings and the (for us) useless beans?

This blog entry answers the second question and at least gives one hint for the first one. Lets start with the second question.

Reading the documentation Oracle® Fusion Middleware Web User Interface Developer’s Guide for Oracle Application Development Framework shows how to turn on/off the automatic component binding via JDeveloper for a page or fragment

Automatic Component Binding On/Off

Automatic Component Binding On/Off

If you turn the automatic binding on you’ll notice a comment line in your jsxp file


This entry in the file triggers the automatic binding. Removing it has the same effect as turning the feature off in the above dialog.
So, as the doc stated, turning the automatic binding off only has an effect for components which are put onto the page in the future. If your page contains e.g. one or more forms, there are many components which are bound needlessly to a bean. It’s an error prone task to go through the source and remove all the bindings properties by hand.
JDeveloper allows us to use regular expressions in search and replace operations (even in search and replace in files). Looking to the source of the jspx page reveals

    <af:document id="d2" binding="#{backingBeanScope.ffff.d2}">
      <af:messages id="m2" binding="#{backingBeanScope.ffff.m2}"/>
      <af:form id="f2" binding="#{backingBeanScope.ffff.f2}">
        <af:panelStretchLayout topHeight="50px" id="psl2"

that the automatic bindings all are looking like ‘binding=”#{backingBeanScope.ffff.<id>’, so we only need a regular expression looking for this string and replace it with nothing.

Replace Dialog

Replace Dialog

Running the dialog above shows that the expression finds the desired targets
Running Replace

Running Replace

After all references to the bean have been deleted, we can simply delete the bean itself. This concludes the answer to the second question.

The answer to the first question is not that easy to give. First of all I found out, that if you once turned the automatic component binding on, it stays on for all other pages you put into the same task flow. It may stay on for all pages, but I couldn’t confirm this in all cases. At some time a developer turned this feature on in the dialog you see when you create a new page (or fragment) in the bounded task flow

Create Page Dialog

Create Page Dialog

You have to click the ‘+’ sign by ‘Page Implementation’ to see the option. The thing is, the next time you create a new page the ‘Page Implementation’ is disclosed and you have to open it to see the current state. As I mentioned before, the option keeps its setting in the task flow. This answers the question of how we end up with so many pages using this feature. A developer turned this on for some reason and all pages added to the task flow later on inherited the behavior.
One interesting thing to note is, that you don’t see the ‘Bindings’ property for components, if you have the automatic component binding turned on
Bindings visible - Automatic Component Binding Off

Bindings visible - Automatic Component Binding Off

Binding invisible - Automatic Component Bindings On

Binding invisible - Automatic Component Bindings On

A summery of this is that you should only use the ‘Automatic Component Binding’ feature if you really need it. If you turn it on, make sure to check its status often and turn it off when not needed.

2 thoughts on “Remove Automatic Component Bindings

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