Feature: Add a dropdown options setter (#8833)

* Feature: Add a setOptions method to field_dropdown

* add test for changing droopdown options

* split out setOptions tests into their own test suite

* Add additional tests

* auto format files

Author: RoboErikG

core/field_dropdown.ts

@@ -136,26 +136,11 @@ export class FieldDropdown extends Field<string> {
     // If we pass SKIP_SETUP, don't do *anything* with the menu generator.
     if (menuGenerator === Field.SKIP_SETUP) return;
 
-    if (Array.isArray(menuGenerator)) {
-      this.validateOptions(menuGenerator);
-      const trimmed = this.trimOptions(menuGenerator);
-      this.menuGenerator_ = trimmed.options;
-      this.prefixField = trimmed.prefix || null;
-      this.suffixField = trimmed.suffix || null;
-    } else {
-      this.menuGenerator_ = menuGenerator;
-    }
-
-    /**
-     * The currently selected option. The field is initialized with the
-     * first option selected.
-     */
-    this.selectedOption = this.getOptions(false)[0];
+    this.setOptions(menuGenerator);
 
     if (config) {
       this.configure_(config);
     }
-    this.setValue(this.selectedOption[1]);
     if (validator) {
       this.setValidator(validator);
     }
@@ -414,6 +399,28 @@ export class FieldDropdown extends Field<string> {
     return this.generatedOptions;
   }
 
+  /**
+   * Update the options on this dropdown. This will reset the selected item to
+   * the first item in the list.
+   *
+   * @param menuGenerator The array of options or a generator function.
+   */
+  setOptions(menuGenerator: MenuGenerator) {
+    if (Array.isArray(menuGenerator)) {
+      this.validateOptions(menuGenerator);
+      const trimmed = this.trimOptions(menuGenerator);
+      this.menuGenerator_ = trimmed.options;
+      this.prefixField = trimmed.prefix || null;
+      this.suffixField = trimmed.suffix || null;
+    } else {
+      this.menuGenerator_ = menuGenerator;
+    }
+    // The currently selected option. The field is initialized with the
+    // first option selected.
+    this.selectedOption = this.getOptions(false)[0];
+    this.setValue(this.selectedOption[1]);
+  }
+
   /**
    * Ensure that the input value is a valid language-neutral option.
    *

tests/mocha/field_dropdown_test.js

@@ -195,6 +195,52 @@ suite('Dropdown Fields', function () {
       assertFieldValue(this.field, 'B', 'b');
     });
   });
+  suite('setOptions', function () {
+    setup(function () {
+      this.field = new Blockly.FieldDropdown([
+        ['a', 'A'],
+        ['b', 'B'],
+        ['c', 'C'],
+      ]);
+    });
+    test('With array updates options', function () {
+      this.field.setOptions([
+        ['d', 'D'],
+        ['e', 'E'],
+        ['f', 'F'],
+      ]);
+      assertFieldValue(this.field, 'D', 'd');
+    });
+    test('With generator updates options', function () {
+      this.field.setOptions(function () {
+        return [
+          ['d', 'D'],
+          ['e', 'E'],
+          ['f', 'F'],
+        ];
+      });
+      assertFieldValue(this.field, 'D', 'd');
+    });
+    test('With trimmable options gets trimmed', function () {
+      this.field.setOptions([
+        ['a d b', 'D'],
+        ['a e b', 'E'],
+        ['a f b', 'F'],
+      ]);
+      assert.deepEqual(this.field.prefixField, 'a');
+      assert.deepEqual(this.field.suffixField, 'b');
+      assert.deepEqual(this.field.getOptions(), [
+        ['d', 'D'],
+        ['e', 'E'],
+        ['f', 'F'],
+      ]);
+    });
+    test('With an empty array of options throws', function () {
+      assert.throws(function () {
+        this.field.setOptions([]);
+      });
+    });
+  });
 
   suite('Validators', function () {
     setup(function () {