[Dashboard] [Embeddable] Add Ability to Defer Embeddable Loaded State

[ThomThomson]

Defer Embeddable Loading

This PR introduces a new opt-in method for embeddables to defer the completion of their loading state until after their output has been completely initialized.

Previously, all embeddables were expected to have their output initialized via the factory create method & the embeddable constructor. This meant that the container could immediately set each embeddable's finished state to true as soon as the constructor returned an embeddable. As part of Time to Visualize, some embeddables were simplified to initialize their output after the constructor, so that their input could be either by value or by reference.

This PR changes Lens and Maps embeddables to defer their loading state in this way.

Dashboard Index Patterns

In the initial setup for Time to Visualize, panels could be fully loaded before updating their index patterns. This meant that dashboard needed to check for new index patterns on every output update on every one of its children. By delaying the loaded state until the embeddable setup is complete, this is no longer necessary. In this PR the dashboard index pattern subscription only listens to output updates from the container itself.

Additionally, a new check has been added to cover the case where:

• no index patterns have been returned yet
• There is at least one child on the page
• There is at least one child loading

If this case is met, the default index pattern will not be loaded. This fixes #105182

The dashboard app has also been changed to no longer require an index pattern in order to render. This can speed up the initial rendering of the dashboard slightly. It will also introduce some mild layout shifting until #107041 is resolved.

Potential Followup

This change can be a major step towards removing the requirement for embeddable factories to have both create and createFromSavedObject methods.

Checklist

Delete any items that are not applicable to this PR.

• Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios

[ThomThomson]

@elasticmachine merge upstream master

[Dosant]

looks good, I am in favor of going with such approach and don't have any better alternatives in mind

[elasticmachine]

Pinging @elastic/kibana-presentation (Team:Presentation)

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServices)

[ThomThomson]

@elasticmachine merge upstream

[nreese]

maps changes LGTM

[Dosant]

Changes LGTM, I tested different combinations of lenses and tsvbs that have multiple index patterns, didn't notice any regressions in terms of how index patterns and filtering works on a dashboard.
tested that no more wrongly requested default index pattern 👍

[crob611]

Looks good to me 👍

[timroes]

Tested on Chrome Linux. It resolves the issue with requesting the default index pattern even if there is no visualization using it. Talked to Devon offline and suggested moving the parent check into the asbtract embeddable to make the usage in the embeddable a bit nicer to read, but so far everything looks fine for me.

[ThomThomson]

Great call @timroes , I've implemented a setInitializationFinished method on the abstract embeddable to make the implementation a little easier. Thanks again!

[nreese]

maps changes LGTM

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 043246c
• Storybooks Preview
• Documentation Changes

Metrics [docs]

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
dashboard	221.9KB	221.4KB	-457.0B
lens	1.7MB	1.7MB	+80.0B
maps	3.2MB	3.2MB	+94.0B
total			-283.0B

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
embeddable	182.6KB	183.0KB	+449.0B

Unknown metric groups

API count

id	before	after	diff
embeddable	460	467	+7
maps	213	214	+1
total			+8

API count missing comments

id	before	after	diff
embeddable	388	391	+3
maps	212	213	+1
total			+4

History

• 💔 Build #144904 failed f67455a
• 💚 Build #144158 succeeded cc06147
• 💚 Build #144102 succeeded e11ebc4
• 💚 Build #141943 succeeded c43fac9
• 💔 Build #141774 failed b578788

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@elasticmachine merge upstream