Add client-side User class derived from @dougal/user.

Adds methods to communicate with the backend.

lib/www/client/source/src/lib/user/User.js

@@ -0,0 +1,97 @@
+
+import { User as BaseUser } from '@dougal/user';
+
+class User extends BaseUser {
+
+  api // Instance of Vuex api method
+  dirty // Whether the values have changed since last saved
+
+  constructor (data, client) {
+    super (data);
+
+    if (client) {
+      this.api = client;
+    } else if (data instanceof User) {
+      this.api = data.api;
+    }
+
+    this.dirty = false;
+    this.on("changed", () => this.dirty = true);
+  }
+
+  static async fromAPI (api, id) {
+    if (id) {
+      const url = `/user/${id}`;
+      const res = await api([url]);
+      return new User(res, api);
+    } else {
+      const url = `/user`;
+      const res = await api([url]);
+      return res?.map( row => new User(row, api) );
+    }
+  }
+
+  /** Save this user to the server
+   *
+   * If this is a new user, the `api` parameter must be
+   * supplied and this will result in a `POST` request.
+   * For an existing user coming from the database,
+   * `this.api` will be used for a `PUT` request.
+   */
+  async save (api) {
+    if (this.api) {
+      const url = `/user/${this.id}`;
+      const init = {
+        headers: {
+          "Content-Type": "application/json"
+        },
+        method: "PUT",
+        body: this.toJSON()
+      };
+      const res = await this.api([url, init]);
+      if (res) {
+        this.dirty = false;
+        return new User(res, this.api);
+      } else {
+        // Something has gone wrong
+        console.log("Something has gone wrong (PUT)");
+      }
+    } else if (api) {
+      const url = `/user`;
+      const init = {
+        headers: {
+          "Content-Type": "application/json"
+        },
+        method: "POST",
+        body: this.toJSON()
+      }
+      const res = await api([url, init]);
+      if (res) {
+        return new User(res, api);
+      } else {
+        // Something has gone wrong
+        console.log("Something has gone wrong (POST)");
+      }
+    } else {
+        throw new Error("Don't know how to save this user");
+    }
+  }
+
+  /** Delete this user from the server
+   */
+  async remove () {
+      const url = `/user/${this.id}`;
+      const init = {
+        headers: {
+          "Content-Type": "application/json"
+        },
+        method: "PUT",
+        body: this.toJSON()
+      };
+      const res = await this.api([url, init]);
+      console.log("remove RES", res);
+  }
+
+}
+
+export default User;