chore(row-selection): WIP implement row plugin

Author: NullVoxPopuli

ember-headless-table/src/plugins/-private/base.ts

@@ -7,7 +7,7 @@ import type { Table } from '../../-private/table';
 import type { ColumnReordering } from '../column-reordering';
 import type { ColumnVisibility } from '../column-visibility';
 import type { Class, Constructor } from '[private-types]';
-import type { Column } from '[public-types]';
+import type { Column, Row } from '[public-types]';
 import type {
   ColumnMetaFor,
   ColumnOptionsFor,
@@ -19,6 +19,7 @@ import type {
 
 const TABLE_META = new Map<string, Map<Class<unknown>, any>>();
 const COLUMN_META = new WeakMap<Column, Map<Class<unknown>, any>>();
+const ROW_META = new WeakMap<Row, Map<Class<unknown>, any>>();
 
 type InstanceOf<T> = T extends Class<infer Instance> ? Instance : T;
 
@@ -250,6 +251,29 @@ export const meta = {
     });
   },
 
+  /**
+   * @public
+   *
+   * For a given row and plugin, return the meta / state bucket for the
+   * plugin<->row instance pair.
+   *
+   * Note that this requires the row instance to exist on the table.
+   */
+  forRow<P extends BasePlugin<any>, Data = unknown>(
+    row: Row<Data>,
+    klass: Class<P>,
+  ): RowMetaFor<SignatureFrom<P>> {
+    return getPluginInstance(ROW_META, row, klass, () => {
+      let plugin = row.table.pluginOf(klass);
+
+      assert(`[${klass.name}] cannot get plugin instance of unregistered plugin class`, plugin);
+      assert(`<#${plugin.name}> plugin does not have meta specified`, plugin.meta);
+      assert(`<#${plugin.name}> plugin does not specify row meta`, plugin.meta.row);
+
+      return new plugin.meta.row(row);
+    });
+  },
+
   /**
    * @public
    *
@@ -413,10 +437,10 @@ export const options = {
 /**
  * @private
  */
-function getPluginInstance<RootKey extends string | Column<any>, Instance>(
+function getPluginInstance<RootKey extends string | Column<any> | Row<any>, Instance>(
   map: RootKey extends string
     ? Map<string, Map<Class<Instance>, Instance>>
-    : WeakMap<Column, Map<Class<Instance>, Instance>>,
+    : WeakMap<Column | Row, Map<Class<Instance>, Instance>>,
   rootKey: RootKey,
   mapKey: Class<Instance>,
   factory: () => Instance

ember-headless-table/src/plugins/row-selection/helpers.ts

@@ -0,0 +1,6 @@
+import { meta } from '../-private/base';
+import { RowSelection } from './plugin';
+
+import type { Row } from '../../-private/row';
+
+export const isSelected = (row: Row) => meta.forRow(row, RowSelection).isSelected;

ember-headless-table/src/plugins/row-selection/index.ts

@@ -0,0 +1,7 @@
+// Public API
+export * from './helpers';
+export { RowSelection as Plugin } from './plugin';
+export { RowSelection } from './plugin';
+
+// Public types
+export type { Signature } from './plugin';

ember-headless-table/src/plugins/row-selection/plugin.ts

@@ -0,0 +1,50 @@
+import { tracked } from '@glimmer/tracking';
+
+import { BasePlugin } from '../-private/base';
+
+import type { Row, Table } from '[public-types]';
+import type { PluginSignature } from '#interfaces';
+
+type Identifier = string | number | symbol;
+
+export interface Signature<DataType> extends PluginSignature {
+  Meta: {
+    Row: RowMeta;
+  };
+  Options: {
+    Plugin: {
+      /**
+       * For a given row's data, how should the key be determined?
+       * this could be a remote id from a database, or some other attribute
+       */
+      key: (data: DataType) => Identifier;
+
+      onSelect: (row: Row) => void;
+      selected: Identifier;
+    };
+  };
+}
+
+/**
+ * This plugin provides a means of managing selection of a single row in a table.
+ *
+ * The state of what is actually selected is managed by you, but this plugin
+ * will wire up the click listeners as well as let you know which *data* is clicked.
+ */
+export class RowSelection<DataType> extends BasePlugin<Signature<DataType>> {
+  name = 'row-selection';
+
+  meta = {
+    row: RowMeta,
+  };
+
+  rowModifier = (element: HTMLElement, []: RowApi<Table<DataType>>) => {};
+}
+
+class RowMeta {
+  @tracked isSelected = false;
+
+  toggle = () => (this.isSelected = !this.isSelected);
+  select = () => (this.isSelected = true);
+  deselect = () => (this.isSelected = false);
+}