v3: static query dependency tree

[ahdinosaur]

had a radical idea for a new way to do queries, which eliminates the stupid query() + shouldQueryAgain() madness.

[iainkirkpatrick]

on it 🏀

[ahdinosaur]

picking this back up

[ahdinosaur]

published 3.0.0-pre.0 as prerelease

(with npm publish --tag prerelease so as not to publish as latest when you npm install feathers-action-react)

[ahdinosaur]

upgraded:

• dogstack-example: https://github.com/root-systems/dogstack-example/tree/far3
• dogstack-agents: https://github.com/root-systems/dogstack-agents/tree/far3

have yet to do anything complex, like dependent queries

[ahdinosaur]

ready for review @iainkirkpatrick @gregorykan!

[ahdinosaur]

notice a bug when navigating to the same container with different route params, the container thinks all the queries have already happened, so doesn't re-query. need a way to invalidate the entire query set, like match: selector so match: getCurrentThingId.

[ahdinosaur]

open question: should a query's selectors (id and/or params) be resolved before the dependencies are ready?

example:

      {
        name: 'childTaskWorks',
        service: 'taskWorks',
        dependencies: [
          'childTaskPlans',
        ],
        params: createSelector(
          getCurrentTaskPlan,
          pipe(
            prop('childTaskPlans'),
            map(prop('id')),
            (childTaskPlanIds) => ({
              query: {
                taskPlanId: {
                  $in: childTaskPlanIds
                }
              }
            })
          )
        )
      }

on the one hand, selectors should probably be defensive anyways, so they should work no matter the data. on the other hand, we could handle this case to be helpful and friendly.

[ahdinosaur]

patch to fix the dependent query selectors:

diff --git a/index.js b/index.js
index 2349cf9..ab0d871 100644
--- a/index.js
+++ b/index.js
@@ -270,19 +270,23 @@ const getQuerys = createSelector(
       const hasReadyDependencies = hasReadyDependenciesByQuery[query.name]
 
       const isStarted = not(isNil(cid))
-      // TODO clean up
-      const id = resolveQueryArg('id')(null)(query)(state, ownProps)
-      // need to clone params because feathers mutates the params during a request.
-      const params = clone(resolveQueryArg('params')({})(query)(state, ownProps))
-      var prevArgs
-      if (isStarted) {
-        prevArgs = {
+      var prevArgs = isStarted
+        ? {
           // TODO clean up
           id: isNil(args.id) ? null: args.id,
           params: isNil(args.params) ? {}: args.params
         }
-      } else {
-        prevArgs = null
+        : {
+          id: null,
+          params: null
+        }
+      var id, params
+      // don't resolve id or params until dependencies are ready
+      if (hasReadyDependencies) {
+        // TODO clean up
+        id = resolveQueryArg('id')(null)(query)(state, ownProps)
+        // need to clone params because feathers mutates the params during a request.
+        params = clone(resolveQueryArg('params')({})(query)(state, ownProps))
       }
       const nextArgs = { id, params }
       const isSameArgs = deepEqual(prevArgs, nextArgs)

[ahdinosaur]

and how to make selector more defensive:

      {
        name: 'childTaskWorks',
        service: 'taskWorks',
        dependencies: [
          'childTaskPlans',
        ],
        params: createSelector(
          getCurrentTaskPlan,
          ifElse(
            isNil,
            () => null,
            pipe(
              prop('childTaskPlans'),
              map(prop('id')),
              (childTaskPlanIds) => ({
                query: {
                  taskPlanId: {
                    $in: childTaskPlanIds
                  }
                }
              })
            )
          )
        )
      }

[ahdinosaur]

one idea: what if you could depend on a query in a parent component? we could register each query by name in the global react context, rather than local react state.