cadorn / appengine

Google App Engine for Javascript

App Engine JavaScript SDK

Welcome to App Engine for JavaScript! With App Engine, you can build web applications using the JavaScript programming language, and take advantage of the many libraries, tools and frameworks for JavaScript that professional developers use to build world-class web applications. Your JavaScript application runs on Google's scalable infrastructure on top of Java and Rhino, and uses large-scale persistent storage and services.

This is a community project, not affiliated in any way with Google.

• Source & Download: http://github.com/gmosx/appengine/
• Status updates: http://twitter.com/appenginejs
• Homepage: http://appenginejs.org/
• Documentation: http://appenginejs.org
• Mailing list: http://groups.google.com/group/appenginejs
• Issue tracking: http://github.com/gmosx/appengine/issues
• IRC: #appenginejs on irc.freenode.net

This SDK is part of the Nitro ecosystem of Web Application development resources. The SDK tracks the latest developments in the CommonJS group.

Design and Implementation

The SDK is powered by Rhino on top of App Engine Java. However, the API is based on App Engine Python. In our view, the design of the Python API is closer to the JavaScript world.

As a result, a developer can consult the App Engine Python documentation to work effectively with the JavaScript SDK.

We use JavaScript coding conventions. Python names like 'this_is_a_name' are converted to JavaScript names like 'thisIsAName'. Moreover all delete() functions are renamed to .remove() functions to avoid collisions with the delete keyword (a DELETE() alias is also provided but it's uses is not recommended and may be deprecated in the future).

Datastore

The Python ext/db api is supported. The API is slightly different to better fit JavaScript.

var db = require("google/appengine/ext/db");

var Category = db.Model("Category", {
    label: new db.StringProperty(),
    category: new db.ReferenceProperty({referenceClass: Category})
});

var c = new Category({keyName: "news", label: News"});
c.put();
var key = ...
var c1 = Category.get(key);
var c2 = Category.getByKeyName("news");
var categories = Category.all().limit(3).fetch();

Blobstore

form:

var blobstore = require("google/appengine/api/blobstore");

exports.GET = function(env) {
    return {data: {
        uploadURL: blobstore.createUploadUrl("/test")
    }}
}

<form action="{uploadURL}" method="POST" enctype="multipart/form-data">
    <p>
        <input type="file" name="file" />
    </p>
    <p>       
        <button type="submit">Upload</button>
    </p>
</form>

upload:

var blobstore = require("google/appengine/api/blobstore");

exports.GET = function(env) {
    return {data: {
        uploadURL: blobstore.createUploadUrl("/save")
    }}
}

save:

var blobstore = require("google/appengine/api/blobstore");

exports.POST = function(env) {
    var blobs = blobstore.getUploadedBlobs(env);
    
    return {
        status : 303,
        headers : {
            "Location": "/serve?key=" + blobs.file.toString()
        }
    };     
}

serve:

var blobstore = require("google/appengine/api/blobstore");

exports.GET = function(env) {
    var params = new Request(env).GET();
    return blobstore.serve(params.key, env);
}

URL Fetch

var fetch = require("google/appengine/api/urlfetch").fetch;

var response = fetch("http://www.appenginejs.org"),
    html = response.content.decodeToString("UTF-8");

Images

var images = require("google/appengine/api/images");
var i = images.resize(params.image.data, 640, 480);

Email

var EmailMessage = require("google/appengine/api/mail").EmailMessage;

new EmailMessage({
    sender: "[email protected]",
    to: "[email protected]",
    subject: "My email",
    body: template.render(params)
}).send();

Memcache

var memcache = require("google/appengine/api/memcache");

var fragment = memcache.get("fragment");
if (!fragment) {
    ...
    memcache.set("fragment", fragment);
}

Users

var users = require("google/appengine/api/users");

var user = users.getCurrentUser();

if (users.isCurrentUserAdmin()) {
    ...
}

var url = user.createLoginURL();

Task Queue

var taskqueue = require("google/appengine/api/labs/taskqueue");

taskqueue.add({url: "/worker", method: "GET", params: {par1: "hello", par2: "world"}});  

var task = new Task({url: "/worker", method: "GET", params: {par1: "hello", par2: "world"}});
task.add("customqueue");

Forms

var Article = require("article").Article,
    ModelForm = require("google/appengine/ext/db/forms").ModelForm,
    ArticleForm = ModelForm(Article);

    ...
    
var form = new ArticleForm(params, {instance: article});
    ...
    form.save();

Example

For an example of the usage of this library have a look at the blog-gae example.

Component status

This library is under construction but usable. Substantial parts of the Python API are converted.

• google/appengine/api/memcache: 80% (usable)
• google/appengine/api/urlfetch: 80% (usable)
• google/appengine/api/mail: 60% (usable)
• google/appengine/api/images: 60% (usable)
• google/appengine/api/users: 80% (usable)
• google/appengine/api/labs/taskqueue: 80% (usable)
• google/appengine/ext/db: 80% (usable, expect minor API changes)
• google/appengine/ext/db/forms: 30% (expect API changes)
• google/appengine/ext/blobstore: 40% (usable)

Credits

• George Moschovitis, [email protected]
• Roberto Saccon [email protected]

Google App Engine

This is a community project, not affiliated in any way with Google.

Google App Engine is a service of Google, Inc. Copyright (c) 2009 Google, all rights reserved.

License

Copyright (c) 2009 George Moschovitis, http://gmosx.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.