Nested gridfield

[maxime-rainville]

Description

Our friends at Creamarketing have developed a cool Nested GridField extension that allows users to manage a sub relation directly within a parent gridfield.

This is a pretty cool feature. Creamarketing has offered to contribute it back to this module.

User story

As a content author, I want a way to access nested relations in a GrdiField without having to drill down to individual records.

Acceptance criteria

• Nested relations can be displayed in a secondary GridField within a primary GridField.
• Nested GridField can work with Has_many and many_many relations.
• The solution can work in both ModelAdmin and GridFields in the edit form of a record.
• Developers have an API for exposing specific relations in a nested Gridfield.
• All GridField components in framework and this module can work with Nested GridField.
  • The Orderable gridfiled component works within a single nested gridfield.
• All permission checks on DataObjects are retained inside nested GridFields.
• Code base is targeted to the namespace of the symbiote/silverstripe-gridfieldextensions module.
• Solution is functional with the Silverstripe CMS native GridField state management solution.
• Solution includes comprehensive PHPUnit tests.
• All user facing string are localised and provide a default English translation.
• The nested gridfield state when navigating between pages is retained.
• Nested Gridfield can be nested inside other nested GridFields to at least 10 levels.
• A maximum nested Gridfield recursion limit can be configured and has a sensible default value.
• DataObject with relations to themselves (e.g.Hierarchy) can be rendered recursively in a nested GridField (this could be used to display a tree in nested GridField)
• The configuration for the nested GridField can be customised by a developer if needed.
• When a record doesn't have any nested relations, nested gridfield can be configured not to show.
  • (Default behaviour to run past the UX team)
• Nested GridField considers use case where a GridField is used to managed constructs that are not DataList/DataObjects. (Throwing meaningful exception is a valid solution for this AC)
• The GridField extensions developer docs are updated to explain how to use nested GridField.
• Developers have to op-in to using the feature.

Excludes

Silverstripe will handle:

• Behat test.
• Risk analysis.
• Adding a nested GridField to frameworktest
• Design review (Maybe not ... need to clear this point with design team)

Other:

• Creamarketing has an enhanced state management solution that works with the nested Gridfield module. This is a seperate concern that may be follow up on in a separate card.
• Creamarketing has a extension that allows rows to be dragged between nested gridfield. This may be look in a follow up card.
• Loading indicator.

PRs

• NEW Nested gridfield #384

[forsdahl]

Added an initial PR for the nested gridfield implementation #384

[GuySartorelli]

PR merged. This will be included in the October minor release.
I've opened #389 to add behat test coverage.

[michalkleiner]

Awesome work @forsdahl!