do not hard-wire column names in annotations (#785)

* enforce column name uniqueness for obs and var

* parameterize the column name containing obs and var user-readable names

* use the new annotation index value from schema

* update f/e unit tests

* PR review suggestions

* lint

client/src/util/stateManager/controlsHelpers.js

@@ -56,13 +56,14 @@ function topNCategories(summary) {
 
 export function createCategoricalSelection(maxCategoryItems, world) {
   const res = {};
+  const obsIndexName = world.schema.annotations.obs.index;
   _.forEach(world.obsAnnotations.colIndex.keys(), key => {
     const summary = world.obsAnnotations.col(key).summarize();
     if (summary.categories) {
       const isColorField = key.includes("color") || key.includes("Color");
       const isSelectableCategory =
         !isColorField &&
-        key !== "name" &&
+        key !== obsIndexName &&
         summary.categories.length < maxCategoryItems;
       if (isSelectableCategory) {
         const [categoryValues, categoryValueCounts] = topNCategories(summary);

client/src/util/stateManager/universe.js

@@ -124,7 +124,7 @@ function reconcileSchemaCategoriesWithSummary(universe) {
   cases, add a 'categories' field to the schema so it is accessible.
   */
 
-  universe.schema.annotations.obs.forEach(s => {
+  universe.schema.annotations.obs.columns.forEach(s => {
     if (
       s.type === "string" ||
       s.type === "boolean" ||
@@ -179,10 +179,10 @@ export function createUniverseFromResponse(
 
   /* Index schema for ease of use */
   universe.schema.annotations.obsByName = fromEntries(
-    universe.schema.annotations.obs.map(v => [v.name, v])
+    universe.schema.annotations.obs.columns.map(v => [v.name, v])
   );
   universe.schema.annotations.varByName = fromEntries(
-    universe.schema.annotations.var.map(v => [v.name, v])
+    universe.schema.annotations.var.columns.map(v => [v.name, v])
   );
   universe.schema.layout.obsByName = fromEntries(
     universe.schema.layout.obs.map(v => [v.name, v])
@@ -213,8 +213,9 @@ export function convertDataFBStoObject(universe, arrayBuffer) {
     throw new Error("Unexpected non-floating point response from server.");
   }
 
+  const varIndexName = universe.schema.annotations.var.index;
   for (let c = 0; c < colIdx.length; c += 1) {
-    const varName = universe.varAnnotations.at(colIdx[c], "name");
+    const varName = universe.varAnnotations.at(colIdx[c], varIndexName);
     result[varName] = columns[c];
   }
   return result;

client/src/util/stateManager/world.js

@@ -263,10 +263,14 @@ function deduceDimensionType(attributes, fieldName) {
 export function createObsDimensions(crossfilter, world, XYdimNames) {
   /*
   create and return a crossfilter with a dimension for every obs annotation
-  for which we have a supported type, *except* 'name'
+  for which we have a supported type, *except* for the index column, indicated
+  by schema.annotations.obs.index.
   */
   const { schema, obsLayout, obsAnnotations } = world;
-  const annoList = schema.annotations.obs.filter(anno => anno.name !== "name");
+  const indexName = schema.annotations.obs.index;
+  const annoList = schema.annotations.obs.columns.filter(
+    anno => anno.name !== indexName
+  );
   crossfilter = annoList.reduce((xfltr, anno) => {
     const dimType = deduceDimensionType(anno, anno.name);
     const colData = obsAnnotations.col(anno.name).asArray();