[visualize] Fix agg param race (#13429)

* [visualize/aggConfig] do not rely on the view to reset params

* [vis/editor/aggParams] check for agg and type before accessing

src/ui/public/vis/agg_config.js

@@ -19,12 +19,16 @@ export function VisAggConfigProvider(Private) {
     self._opts = opts = (opts || {});
     self.enabled = typeof opts.enabled === 'boolean' ? opts.enabled : true;
 
+    // start with empty params so that checks in type/schema setters don't freak
+    // because self.params is undefined
+    self.params = {};
+
     // setters
     self.type = opts.type;
     self.schema = opts.schema;
 
-    // resolve the params
-    self.fillDefaults(opts.params);
+    // set the params to the values from opts, or just to the defaults
+    self.setParams(opts.params || {});
   }
 
   /**
@@ -82,6 +86,15 @@ export function VisAggConfigProvider(Private) {
         }
 
         this.__type = type;
+
+        // clear out the previous params except for a few special ones
+        this.setParams({
+          // split row/columns is "outside" of the agg, so don't reset it
+          row: this.params.row,
+
+          // almost every agg has fields, so we try to persist that when type changes
+          field: _.get(this.getFieldOptions(), ['byName', this.getField()])
+        });
       }
     },
     schema: {
@@ -105,7 +118,7 @@ export function VisAggConfigProvider(Private) {
    *                         used when initializing
    * @return {undefined}
    */
-  AggConfig.prototype.fillDefaults = function (from) {
+  AggConfig.prototype.setParams = function (from) {
     const self = this;
     from = from || self.params || {};
     const to = self.params = {};
@@ -143,22 +156,6 @@ export function VisAggConfigProvider(Private) {
     });
   };
 
-  /**
-   * Clear the parameters for this aggConfig
-   *
-   * @return {object} the new params object
-   */
-  AggConfig.prototype.resetParams = function () {
-    let field;
-    const fieldOptions = this.getFieldOptions();
-
-    if (fieldOptions) {
-      field = fieldOptions.byName[this.fieldName()] || null;
-    }
-
-    return this.fillDefaults({ row: this.params.row, field: field });
-  };
-
   AggConfig.prototype.write = function () {
     return this.type.params.write(this);
   };

src/ui/public/vis/editors/default/agg_params.js

@@ -52,7 +52,7 @@ uiModules
       let $aggParamEditors; //  container for agg type param editors
       let $aggParamEditorsScope;
 
-      function updateAggParamEditor(newType, oldType) {
+      function updateAggParamEditor() {
         if ($aggParamEditors) {
           $aggParamEditors.remove();
           $aggParamEditors = null;
@@ -64,33 +64,23 @@ uiModules
           $aggParamEditorsScope = null;
         }
 
+        if (!$scope.agg || !$scope.agg.type) {
+          return;
+        }
+
         // create child scope, used in the editors
         $aggParamEditorsScope = $scope.$new();
         $aggParamEditorsScope.indexedFields = $scope.agg.getFieldOptions();
-
-        const agg = $scope.agg;
-        if (!agg) return;
-
-        const type = $scope.agg.type;
-
-        if (newType !== oldType) {
-          // don't reset on initial load, the
-          // saved params should persist
-          agg.resetParams();
-        }
-
-        if (!type) return;
-
         const aggParamHTML = {
           basic: [],
           advanced: []
         };
 
         // build collection of agg params html
-        type.params.forEach(function (param, i) {
+        $scope.agg.type.params.forEach(function (param, i) {
           let aggParam;
           let fields;
-          if (agg.schema.hideCustomLabel && param.name === 'customLabel') {
+          if ($scope.agg.schema.hideCustomLabel && param.name === 'customLabel') {
             return;
           }
           // if field param exists, compute allowed fields