[jbossseam-issues] [JBoss JIRA] Commented: (JBSEAM-3330) ICEfaces edit page in seam-gen application updates without save

[Dan Allen (JIRA)]

    [ https://jira.jboss.org/jira/browse/JBSEAM-3330?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12434263#action_12434263 ] 

Dan Allen commented on JBSEAM-3330:
-----------------------------------

The correct solution is to use manual flushing on the conversation. If you put the persistence context into manual flush mode, changes are not sent to the database until flush() is called on the EntityManager. All of the write operations (persist, update, delete) on the EntityHome class make a call to flush(), so there is no need for the developer to worry about this step.

To activate manual flush mode, simply add the flush-mode attribute to begin conversation directive in the *.page.xml file. I have made this change in Seam 2.1 for both the RichFaces and ICEfaces projects.

<begin-conversation flush-mode="MANUAL"/>

Using manual flush mode in seam-gen is very important for two reasons.

1) Any partial submit was causing the record to be updated (in edit mode), so even if you clicked cancel, the changes would have already taken affect.

2) Seam strongly advocates the use of manual flushing, almost to the point that not using it is incorrect. Since only Hibernate supports manual flushing, other JPA providers are broken in this regard.

You may wonder why the RichFaces example was working before without the use of manual flushing. The reason is that the <a:support> tag has the feature of short-circuiting the life cycle prior to the update model values phase, activated with the bypassUpdates="true" attribute. The partial submit in ICEfaces does not perform this short-circuit.

Technically, though, the behavior of ICEfaces is more semantically correct. Skipping the update model values phase has other shortcomings, such as the inability to do cross-field validation easily. Besides, when you navigate away from the form to select a parent entity, that triggers a full JSF life cycle, causing the changes to be sent to the database if you are not using manual flushing.

Here is the lesson. When using a conversation to manage an update operation (i.e., edit mode) you should be using manual flushing. End of story.

> ICEfaces edit page in seam-gen application updates without save
> ---------------------------------------------------------------
>
>                 Key: JBSEAM-3330
>                 URL: https://jira.jboss.org/jira/browse/JBSEAM-3330
>             Project: Seam
>          Issue Type: Feature Request
>          Components: ICE Faces Integration, Tools
>    Affects Versions: 2.0.3.CR1
>         Environment: ICEfaces
>            Reporter: Valerie Griffin
>            Assignee: judy guglielmin
>
> The generated code includes partial submit. Whenever a field is changed, the database is updated without requiring the Save button.
> I've reported this problem to ICEfaces. The fix they propose requires the use of manual flush, which I understand is not universally supported. (The fix is to use manual flush and to override update, persist, and remove to invoke the manual flush.)
> I'm changing my seam-gen files to use that fix but am not including them here because I don't think that's necessarily the best fix. 

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