custom middleware to update cell selection

src/middleware/updateCellSelectionMiddleware.js

@@ -0,0 +1,96 @@
+import uri from "urijs";
+import * as globals from "../globals";
+
+/*
+  https://medium.com/@jacobp100/you-arent-using-redux-middleware-enough-94ffe991e6
+  storeInstance => functionToCallWithAnActionThatWillSendItToTheNextMiddleware => actionThatDispatchWasCalledWith => valueToUseAsTheReturnValueOfTheDispatchCall
+*/
+
+const updateCellSelectionMiddleware = (store) => {
+  return (next) => {
+    return (action) => {
+      const s = store.getState();
+
+      /* this is a hardcoded map of the things we need to keep an eye on and update global cell selection in response to */
+      const filterJustChanged =
+        action.type === "continuous selection using parallel coords brushing" ||
+        action.type === "graph brush selection change" ||
+        action.type === "graph brush deselect"
+        ;
+
+      if (
+        !filterJustChanged ||
+        !s.controls.allCellsOnClient
+        /* graphMap is set at the same time as allCells, so we assume it exists */
+      ) {
+        return next(action); /* if the cells haven't loaded or the action wasn't a filter, bail */
+      }
+
+
+      // metadata has cellname, and that's all we ever need (is a key to graphMap)
+      let newSelection = s.controls.allCellsOnClient.metadata.slice(0);
+
+      /*
+         in plain language...
+
+         (a) once the cells have loaded.
+         (b) each time a user changes ANY control we need to update currentCellSelection
+         there are two states:
+
+         1. control state we already know about (state.foo)
+         2. control states that override states we already know about (action.foo applied instead of state.foo)
+
+      */
+
+      if ( /* is there a 2d graph brush selection ? */
+        action.type === "graph brush selection change" ||
+        s.controls.graphBrushSelection
+      ) {
+
+        const graphBrushSelection = /* it exists, so is it new or old */
+          action.type === "graph brush selection change" ? action.brushCoords :
+          s.controls.graphBrushSelection
+
+        _.each(newSelection, (cell, i) => {
+
+          if (!s.controls.graphMap[cell["CellName"]]) { return } /* this means the cells for which we do not have a graph location will be ALWAYS SELECTED */
+
+          const coords = s.controls.graphMap[cell["CellName"]]; // [0.08005009151334168, 0.6907652173913044]
+
+          const pointIsInsideBrushBounds = (
+            globals.graphXScale(coords[0]) >= graphBrushSelection.northwestX &&
+            globals.graphXScale(coords[0]) <= graphBrushSelection.southeastX &&
+            globals.graphYScale(coords[1]) >= graphBrushSelection.northwestY &&
+            globals.graphYScale(coords[1]) <= graphBrushSelection.southeastY
+          );
+
+          if (!pointIsInsideBrushBounds) {
+            newSelection[i]["__selected__"] = false;
+          } else {
+            newSelection[i]["__selected__"] = true;
+          }
+        })
+      }
+      // if (
+      //   action.type === "continuous selection using parallel coords brushing"
+      // ) {
+      //   newSelection = newSelection.filter((d) => {
+      //     /* this is iterating over the enter dataset */
+      //     if (action.data.every((active) => {
+      //         var dim = active.dimension;
+      //         // test if point is within extents for each active brush
+      //         return dim.type.within(d[dim.key], active.extent, dim);
+      //       })) {
+      //       return true;
+      //     }
+      //   });
+      // }
+
+      let modifiedAction = Object.assign({}, action, {newSelection})
+
+      return next(modifiedAction);
+    }
+  }
+};
+
+export default updateCellSelectionMiddleware;