Load Olm from the global rather than requiring it.

This means that we can avoid confusing everybody in the world about how to
webpack js-sdk apps.

README.md

@@ -236,6 +236,24 @@ host the API reference from the source files like this:
 
 Then visit ``http://localhost:8005`` to see the API docs.
 
+End-to-end encryption support
+=============================
+
+The SDK supports end-to-end encryption via the Olm and Megolm protocols, using
+[libolm](http://matrix.org/git/olm). It is left up to the application to make
+libolm available, via the ``Olm`` global.
+
+To enable support in a browser application:
+
+ * download the transpiled libolm (either via ``npm install olm``, or from
+   https://matrix.org/packages/npm/olm/).
+ * load ``olm.js`` as a ``<script>`` *before* ``browser-matrix.js``.
+ 
+To enable support in a node.js application:
+
+ * ``npm install olm``
+ * ``require('olm');`` *before* ``matrix-js-sdk``.
+
 Contributing
 ============
 *This section is for people who want to modify the SDK. If you just

package.json

@@ -73,16 +73,9 @@
     "uglify-js": "^2.8.26",
     "watchify": "^3.2.1"
   },
-  "optionalDependencies": {
-    "olm": "https://matrix.org/packages/npm/olm/olm-2.2.1.tgz"
-  },
   "browserify": {
     "transform": [
-      "sourceify",
+      "sourceify"
-      "browserify-shim"
     ]
-  },
-  "browserify-shim": {
-    "olm": "global:Olm"
   }
 }

src/client.js

@@ -47,8 +47,7 @@ try {
     var Crypto = require("./crypto");
     CRYPTO_ENABLED = true;
 } catch (e) {
-    console.error("olm load error", e);
+    console.warn("Unable to load crypto module: crypto will be disabled: " + e);
-    // Olm not installed.
 }
 
 /**

src/crypto/OlmDevice.js

@@ -20,11 +20,9 @@ limitations under the License.
  *
  * @module crypto/OlmDevice
  */
-const Olm = require("olm");
+const Olm = global.Olm;
 if (!Olm) {
-    // this happens if we were loaded via browserify and the Olm module was not
+    throw new Error("global.Olm is not defined");
-    // loaded.
-    throw new Error("Olm is not defined");
 }
 const utils = require("../utils");