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I would like some technique/pattern advice on retaining each single bean I bind to my Composite Components.

I am adding composite components to a form pragmatically based on user actions, and when the user is finished I want to harvest the single bean behind each composite component they added. Ex: If user selects & adds 4 composite components, that's one bean for each, so when the user is finished I want the 4 beans with the user's entered values.

This seems a bit hairy in the JSF world, but I continue to dig through stackoverflow and experiment. I'm relatively new to JSF details, but having fun.

I've got the composite components loading, each being given a bean to be used as "cc.attrs.bean" and it properly adds the control to the form. Here is what I am currently doing and what I expected:

  1. Load Composite Component
  2. Instantiate its Bean
  3. Save Bean reference in a separate list in a ViewScoped bean (my hook to the bean for later)
  4. Give Bean to Composite Component (as an attribute)
  5. Add Composite Component to form
  6. ...User interacts with form and Composite Components adding/editing values...
  7. User finally pushes "Done" (now I need the modified beans).
  8. Thought I could get all the user's values from the "separate list in a ViewScoped bean" from #3 above.

My preliminary experiments tell me that if I instantiate the bean, save the bean reference in a separate ViewScoped list then give the bean to the Composite Component, the bean I saved won't have the Composite Component's values. Between all the build/render phases it seems to lose the connection between the bean I saved and the bean the Composite Component is bound to.

I don't know if I should be following this path, or if I should use a FacesComponent event technique to intercept the bean attribute being passed along, or if I should be using filters, or maybe even magical pixie dust etc...

This seemed promising: I already wrap each of my user selectable Composite Components in a single common Wrapper Composite Component (lets me put a nice PrimeFaces collapsible panel frame around them). For example, I put "Composite Component A" into "Wrapper", then I add "Wrapper" to the form. If I passed the single bean as an attribute to both those Composite Components, I was hoping that the FacesComponent event "init" technique on the Wrapper could nicely capture the "real bound bean" in my separate list in the ViewScoped bean. In my attempts on this today I'm having trouble finding the right event type and getting access to the bean... and getting lots of strange errors (probably due to my lack of detailed understanding of the lifecycle).

Stack: Eclipse Mars, JSF 2.2, Mojarra 2.2, Tomcat 8.0

AAron
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  • The question is long winded, but I believe this Q&A duplicates your question http://stackoverflow.com/questions/29032046/how-can-i-cache-data-inside-a-composite-component/ As to "programmatically adding components", this is definitely fishy. You should instead programmatically add a new item to a collection in the model and have the view dynamically iterate over it. Food for read: http://stackoverflow.com/questions/14911158/how-does-the-binding-attribute-work-in-jsf-when-and-how-should-it-be-used – BalusC Sep 16 '15 at 18:59
  • Yup, long winded. I'll own that. – AAron Sep 17 '15 at 01:34
  • I may have misspoke in some of my text. I'm not using binding attributes (just EL on `value`s), and I'm making Composite Components (with a custom bean) be my "plug-in" architecture. How they list in the form doesn't matter (Early on I tried iterating over includes.. yuck). I'm reading what you suggested... Also are you suggesting a collection of my Composite Control `UIComponent`s, with attributes set (ex: my custom bean as `cc.attrs.bean`), and then the view loops over it... how does the loop render / invoke / tie-in each UIComponent? Thanks. – AAron Sep 17 '15 at 01:44
  • Oops! I forgot to mention the user could choose to add **duplicates** to the form. Ex: multiple of "Composite Component A", so I ignored the hide/show approach. – AAron Sep 17 '15 at 02:37

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