Propose UI for Replication Filters

Here is a rough draft of a scope of work for exposing replication filters to the user:

• ReplicationTaskInterface is the input we want to expose to the user for replication (Note: these inputs are inspired by CouchDB's replication settings: http://docs.couchdb.org/en/1.6.1/json-structure.html#replication-settings)
• Modify the form for creating/editing Workspaces to include inputs for the replication settings defined in the ReplicationTaskInterface
• Any UI that triggers execution of ReplicatorInterface::replicate should include the replication settings defined on the Workspace, passing those inputs to ::replicate as a ReplicationTaskInterface.

Here are example implementations:

• Deploy: each deployment created would derive the replication settings from the Workspace (this may be better than having to set the replication settings for each deployment, which may be cumbersome/overwhelming for the user)
• Relaxed: when a Workspace is configured to choose a remote as the upstream it would also be configured with the replication settings appropriate for that remote (this gives more granular control than configuring replication settings on each remote)
• Workspace (via Workbench Moderation): when a Workspace is published it would derive the replication settings from the Workspace (having to set the replication settings each time a Workspace is published may be cumbersome/overwhelming to the user)

Edit: completely revised proposal to assume replication settings are on Workspace.

Changing the description and title to explain this ticket is for defining how modules should interact with replication module. Implementation will be completed in tickets on each module utilizing the replication module.

Yes, choosing UUIDs for replication is a case for replication settings.

I think we should optimize where the location of replication settings based on convenience to the user, which I suspect will be a function largely based on frequency of modification and the context in which they are desired to be modified.

The #2 proposal is for having the replication settings on each Workspace. I think it is a decent starting point, but it doesn't address cases that I imagine would occur:

• Deploy: configuring settings per-deployment, e.g. "I only want to deploy this one piece of content"
• Relaxed: configuring settings per-endpoint, e.g. "I want to guarantee only published articles are replicated to prod"
• Workspace (via WBM): configuring settings per-publish, e.g. "I want to curate all my edits in this workspace to only deploy what I want"

As such, I think we should implement replication settings on the Workspace in a fashion that allows any module to move the replication settings inputs where desired.

Here is an initial set of work:

• Replication changes: https://github.com/relaxedws/drupal-replication/pull/12
• Workspace changes: https://github.com/timmillwood/drupal-workspace/pull/7

I still need to write tests and pass a parameters to filters, i.e. support configurable filters. Attached is a screenshot of the UI.

This solution assumes you are creating "Replication Settings" config entities in code which then get exposed to the UI.

One potential follow up will be to look into exposing a UI for creating / editing "Replication Settings".

I have submitted a patch to expose a UI for replication filters: https://www.drupal.org/node/2749167#comment-11491867

I've attached a screenshot of what configuring a Workspace currently looks like to the user.