FEATURE: Disable overwriting generated properties at transaction level

[rPraml]

We want to backup & restore some data by exporting it to JSON. For this use case we need to preserve

• whenCreated
• whoCreated
• whenModified
• whoModified

This PR allows to disable the update of these properties for a particular transaction

[rbygrave]

I like the feature.

When I first read it I expect the opposite meaning for overwriteGeneratedProperties = true ... which to me means I the developer get to override the generated properties. I want to set it to true to enable me the developer to override the values of the generated properties. Currently in the PR it has the opposite meaning.

I'll ponder this ...

[rPraml]

That depends on which side you look at it from:

• do the developer want to overwrite the generated propertes (and ebean shouldn't set them back)
• or should NOT ebean overwrite previously changed propertes.

I agree, after your comment, the name is not the best. I'm sure we'll find an other one

• noUpdateGenerated (butIfTheyAreNullSetThem) - also a point of view problem
• disableGeneratedUpdate
• ...

[jnehlmeier]

Is it allowed to toggle that switch on/off during the lifespan of the transaction or would that miserably cause problems? If it can be toggled on/off at any time then a setter name seems fine, e.g. setAutoUpdateGeneratedFields(boolean). If we can not toggle the setting at any time then just disableAutoUpdateGeneratedFields() to disable the default setting.

Side note: It would be so cool if that whole generated fields thing would be extendible/configurable. For example I like Who/WhenDeleted as well, because soft-deletion is not a modification of data.

[rPraml]

Generated properties are updated during save, so it is possible to modify it at nearly any time
(you might not change it in a persist callback or in an other thread).

setAutoUpdateGeneratedFields(boolean)

I like that name