[Maps] data load event handlers

[nreese]

fixes #49236

This PR adds eventHandlers parameter to MapEmbeddableFactory.createFromState allowing consumers to register callbacks for onDataLoad, onDataLoadEnd, onDataLoadError.

const eventHandlers = {
  onDataLoad: (layerId: string, dataId: string) => {
    // take action on data load
  },
  onDataLoadEnd: (layerId: string, dataId: string, featuresCount: number) => {
    // take action on data load end
  },
  onDataLoadError: (layerId: string, dataId: string, errorMessage: string) => {
    // take action on data load error
  },
}

const mapEmbeddable = await factory.createFromState(state, input, parent, renderTooltipContent, eventHandlers);

[elasticmachine]

Pinging @elastic/kibana-gis (Team:Geo)

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 017183f

[spong]

@elasticmachine merge upstream

[spong]

Here's a draft PR using this new API: #49589

To meet our use case I created a useMapLayers hook that provides both a global isLoading flag and an array of layer state. Having a global loading flag makes things a bit easier to digest on our end.

Anyway, implementation was pretty seamless (thank-you! 🙂) , only two pieces of feedback:

• The root layer is included within onDataLoad but not onDataLoadEnd. I was able to filter it out to get the desired behavior, but I'm thinking it either shouldn't be there, or also be included in onDataLoadEnd. Thoughts?
• Small naming discrepancy in the API description above for the onDataLoadEnd props -- featureCount (desc) vs featuresCount (as named in code).

Other than that everything looks 👍 Thanks for the added functionality and quick turn-around on this!

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: a24b826

[nreese]

Small naming discrepancy in the API description above for the onDataLoadEnd props -- featureCount (desc) vs featuresCount (as named in code).

Thanks, fixed

The root layer is included within onDataLoad but not onDataLoadEnd. I was able to filter it out to get the desired behavior, but I'm thinking it either shouldn't be there, or also be included in onDataLoadEnd. Thoughts?

There was an uncaught error "Uncaught (in promise) TypeError: Cannot read property 'length' of undefined" resulting in onDataLoadEnd not getting called for that layer. That issue has been resolved.

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: bb95598

[spong]

Updated #49589 against the latest from this PR and no longer seeing an error in the console and onDataLoadEnd now gets called for the EMS layer. LGTM -- thanks @nreese! 👍

[thomasneirynck]

Awesome. One small piece of feedback:

I would wrap the 3rd argument of the callback, featuresCount, into an object. The contents of this argument depend on the layer-type (e.g. tile-layer could have different "completion"-arguments than a heatmap-layer than a vector-layer). featuresCount only applies to vector-layer.

wrt @spong

Having a global loading flag makes things a bit easier to digest on our end.

I'd agree with that, but I'd hesitate to put this global-flag into a first pass at this. It's hard to create a global data-load flag and have it work reliably in Maps. It's not just the data-loading itself, but detecting map-movements, tile-loading, ... those would all have to be wrapped up into this.

[nreese]

@thomasneirynck @spong featuresCount is now wrapped in resultMeta object so different layer types can return different results. featuresCount is only provided for vector layers

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: a529911

[spong]

Updated #49589 against the latest that introduces the resultMeta object and all is good -- LGTM 👍