1 files changed, 154 insertions, 0 deletions
diff --git a/components/jetpack/sdk/ui/frame/model.js b/components/jetpack/sdk/ui/frame/model.js
new file mode 100644
index 000000000..627310874
--- /dev/null
+++ b/components/jetpack/sdk/ui/frame/model.js
@@ -0,0 +1,154 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+module.metadata = {
+  "stability": "experimental",
+  "engines": {
+    "Firefox": "> 28"
+  }
+};
+
+const { Class } = require("../../core/heritage");
+const { EventTarget } = require("../../event/target");
+const { emit, off, setListeners } = require("../../event/core");
+const { Reactor, foldp, send, merges } = require("../../event/utils");
+const { Disposable } = require("../../core/disposable");
+const { OutputPort } = require("../../output/system");
+const { InputPort } = require("../../input/system");
+const { identify } = require("../id");
+const { pairs, object, map, each } = require("../../util/sequence");
+const { patch, diff } = require("diffpatcher/index");
+const { isLocalURL } = require("../../url");
+const { compose } = require("../../lang/functional");
+const { contract } = require("../../util/contract");
+const { id: addonID, data: { url: resolve }} = require("../../self");
+const { Frames } = require("../../input/frame");
+
+
+const output = new OutputPort({ id: "frame-change" });
+const mailbox = new OutputPort({ id: "frame-mailbox" });
+const input = Frames;
+
+
+const makeID = url =>
+  ("frame-" + addonID + "-" + url).
+    split("/").join("-").
+    split(".").join("-").
+    replace(/[^A-Za-z0-9_\-]/g, "");
+
+const validate = contract({
+  name: {
+    is: ["string", "undefined"],
+    ok: x => /^[a-z][a-z0-9-_]+$/i.test(x),
+    msg: "The `option.name` must be a valid alphanumeric string (hyphens and " +
+         "underscores are allowed) starting with letter."
+  },
+  url: {
+    map: x => x.toString(),
+    is: ["string"],
+    ok: x => isLocalURL(x),
+    msg: "The `options.url` must be a valid local URI."
+  }
+});
+
+const Source = function({id, ownerID}) {
+  this.id = id;
+  this.ownerID = ownerID;
+};
+Source.postMessage = ({id, ownerID}, data, origin) => {
+  send(mailbox, object([id, {
+    inbox: {
+      target: {id: id, ownerID: ownerID},
+      timeStamp: Date.now(),
+      data: data,
+      origin: origin
+    }
+  }]));
+};
+Source.prototype.postMessage = function(data, origin) {
+  Source.postMessage(this, data, origin);
+};
+
+const Message = function({type, data, source, origin, timeStamp}) {
+  this.type = type;
+  this.data = data;
+  this.origin = origin;
+  this.timeStamp = timeStamp;
+  this.source = new Source(source);
+};
+
+
+const frames = new Map();
+const sources = new Map();
+
+const Frame = Class({
+  extends: EventTarget,
+  implements: [Disposable, Source],
+  initialize: function(params={}) {
+    const options = validate(params);
+    const id = makeID(options.name || options.url);
+
+    if (frames.has(id))
+      throw Error("Frame with this id already exists: " + id);
+
+    const initial = { id: id, url: resolve(options.url) };
+    this.id = id;
+
+    setListeners(this, params);
+
+    frames.set(this.id, this);
+
+    send(output, object([id, initial]));
+  },
+  get url() {
+    const state = reactor.value[this.id];
+    return state && state.url;
+  },
+  destroy: function() {
+    send(output, object([this.id, null]));
+    frames.delete(this.id);
+    off(this);
+  },
+  // `JSON.stringify` serializes objects based of the return
+  // value of this method. For convinienc we provide this method
+  // to serialize actual state data.
+  toJSON: function() {
+    return { id: this.id, url: this.url };
+  }
+});
+identify.define(Frame, frame => frame.id);
+
+exports.Frame = Frame;
+
+const reactor = new Reactor({
+  onStep: (present, past) => {
+    const delta = diff(past, present);
+
+    each(([id, update]) => {
+      const frame = frames.get(id);
+      if (update) {
+        if (!past[id])
+          emit(frame, "register");
+
+        if (update.outbox)
+          emit(frame, "message", new Message(present[id].outbox));
+
+        each(([ownerID, state]) => {
+          const readyState = state ? state.readyState : "detach";
+          const type = readyState === "loading" ? "attach" :
+                       readyState === "interactive" ? "ready" :
+                       readyState === "complete" ? "load" :
+                       readyState;
+
+          // TODO: Cache `Source` instances somewhere to preserve
+          // identity.
+          emit(frame, type, {type: type,
+                             source: new Source({id: id, ownerID: ownerID})});
+        }, pairs(update.owners));
+      }
+    }, pairs(delta));
+  }
+});
+reactor.run(input);