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From bows...@apache.org
Subject [2/2] docs commit: First draft of the guide
Date Mon, 16 Jul 2012 21:15:17 GMT
First draft of the guide


Project: http://git-wip-us.apache.org/repos/asf/incubator-cordova-docs/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-cordova-docs/commit/1385e8e2
Tree: http://git-wip-us.apache.org/repos/asf/incubator-cordova-docs/tree/1385e8e2
Diff: http://git-wip-us.apache.org/repos/asf/incubator-cordova-docs/diff/1385e8e2

Branch: refs/heads/master
Commit: 1385e8e200c1bf8cd0e384a2cc31f39e020e3a82
Parents: 3638335
Author: Joe Bowser <bowserj@apache.org>
Authored: Mon Jul 16 14:14:06 2012 -0700
Committer: Joe Bowser <bowserj@apache.org>
Committed: Mon Jul 16 14:14:06 2012 -0700

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 docs/en/edge/guide/android/index.md |  114 ++++++++++++++++++++++++++++++
 1 files changed, 114 insertions(+), 0 deletions(-)
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http://git-wip-us.apache.org/repos/asf/incubator-cordova-docs/blob/1385e8e2/docs/en/edge/guide/android/index.md
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diff --git a/docs/en/edge/guide/android/index.md b/docs/en/edge/guide/android/index.md
new file mode 100644
index 0000000..108c5ee
--- /dev/null
+++ b/docs/en/edge/guide/android/index.md
@@ -0,0 +1,114 @@
+---
+license: Licensed to the Apache Software Foundation (ASF) under one
+         or more contributor license agreements.  See the NOTICE file
+         distributed with this work for additional information
+         regarding copyright ownership.  The ASF licenses this file
+         to you under the Apache License, Version 2.0 (the
+         "License"); you may not use this file except in compliance
+         with the License.  You may obtain a copy of the License at
+
+           http://www.apache.org/licenses/LICENSE-2.0
+
+         Unless required by applicable law or agreed to in writing,
+         software distributed under the License is distributed on an
+         "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+         KIND, either express or implied.  See the License for the
+         specific language governing permissions and limitations
+         under the License.
+---
+
+Writing an Cordova-Android Plugin
+==================================
+
+Writing a plugin requires an understanding of the architecture of Cordova-Android.  Cordova
consists
+of a WebView with hooks attached to it.  These plugins are represented as sub-classes in
the config.xml
+file.
+
+A plugin will consist of at least a single Java class that extends the Plugin object.  This
object MUST
+have a method called execute that must return a pluginresult.  In addition to this, there
is a best practice that
+the plugin should handle pause and resume events, and should handle message passing between
plugins.
+
+Writing the Java portion:
+--------------------------------
+Assuming that you know how Javascript plugins work, you must use the exec method as follows:
+
+{{
+exec(<successFunction>, <failFunction>, <service>, <action>, [<args>]);
+}}
+
+
+This will send the message to Java to start work on your plugin.  Then you must handle what
+comes into the plugin in the execute command.  Most execute commands look like the following:
+
+{{
+    public PluginResult execute(String action, JSONArray args, String callbackId) {
+        PluginResult.Status status = PluginResult.Status.OK;
+        String result = "";
+
+        try {
+            if (action.equals("beep")) {
+                this.beep(args.getLong(0));
+            }
+            else if (action.equals("vibrate")) {
+                this.vibrate(args.getLong(0));
+            }
+            else if (action.equals("alert")) {
+                this.alert(args.getString(0), args.getString(1), args.getString(2), callbackId);
+                PluginResult r = new PluginResult(PluginResult.Status.NO_RESULT);
+                r.setKeepCallback(true);
+                return r;
+            }
+            else if (action.equals("confirm")) {
+                this.confirm(args.getString(0), args.getString(1), args.getString(2), callbackId);
+                PluginResult r = new PluginResult(PluginResult.Status.NO_RESULT);
+                r.setKeepCallback(true);
+                return r;
+            }
+            else if (action.equals("activityStart")) {
+                this.activityStart(args.getString(0), args.getString(1));
+            }
+            else if (action.equals("activityStop")) {
+                this.activityStop();
+            }
+            else if (action.equals("progressStart")) {
+                this.progressStart(args.getString(0), args.getString(1));
+            }
+            else if (action.equals("progressValue")) {
+                this.progressValue(args.getInt(0));
+            }
+            else if (action.equals("progressStop")) {
+                this.progressStop();
+            }
+            return new PluginResult(status, result);
+        } catch (JSONException e) {
+            return new PluginResult(PluginResult.Status.JSON_EXCEPTION);
+        }
+    }
+}}
+
+When catching exceptions and returning errors, it's important that the error we return to
Javascript match the Java exception as much as possible, otherwise the developer won't know
what
+is going on with the device.
+
+Adding your plugin to a project:
+---------------------------------
+Whether you distribute your plugin as Java file, or whether it's in a JAR of its own, the
plugin must be added with this XML:
+{{
+    <plugin name="<service_name>" value="<full_name_including_namespace>"/>
+}}
+
+The service name will be what you use in exec to call the plugin, and the value will be the
full name of the Java class including the namespace.  Withotu this added, the plugin may compile
but 
+will not be reachable by Cordova.
+
+Debugging Plugins
+-----------------------
+Eclipse can be used to debug an Android project, and the plugins can be debugged if the Java
source is included in the project.  Only the latest version of the Android Dev Tools is known
to allow source code attachment to JAR dependencies, this is not fully supported at this time.
+
+Common Pitfalls:
+-------------------------------
+* Plugins have access to a CordovaInterface object.  This object has access to the activity
that is running the application, which of course, is the context required to launch
+a new intent.  The CordovaInterface allows plugins to  start an activity for a result, and
to set the callback plugin for when the intent comes back to the application.  This is important,
since the
+intents system is how Android communicates between processes.
+
+* Plugins do not have direct access to the Context as they have in the past.  ctx id deprecated,
and will be removed six months after 2.0 is released.  All the methods that ctx have exist
on the context, so both getContext() and getActivity() are capable of returning the proper
object required.
+
+* Avoid calling Javascript using webView.loadUrl().  The reason we have a callback server
is to allow Javascript execution to be thread-safe, and loadUrl explicitly interrupts the
UI thread, and can affect the usability of your plugin.


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