how can I use google app engine with an application in phonegap - google-app-engine

I have been developing a Phonegap client application, I need to create a web service that storage all the data that i will be sending through the app.
I want to use google app engine to create the database and the web service.
I have read a lot, but i don't find a concrete example of how to do it and how to call the web service then from the application with phonegap.
Anyone have an example of how to do this?

You can use Cloud Endpoints with your app:
Google Cloud Endpoints consists of tools, libraries and capabilities
that allow you to generate APIs and client libraries from an App
Engine application, referred to as an API backend, to simplify client
access to data from other applications. Endpoints makes it easier to
create a web backend for web clients and mobile clients such as
Android or Apple's iOS.
For mobile developers, Endpoints provides a simple way to develop a
shared web backend and also provides critical infrastructures, such as
OAuth 2.0 authentication, eliminating a great deal of work that would
otherwise be needed. Furthermore, because the API backend is an App
Engine app, the mobile developer can use all of the services and
features available in App Engine, such as Datastore, Google Cloud
Storage, Mail, Url Fetch, Task Queues, and so forth. And finally, by
using App Engine for the backend, developers are freed from system
admin work, load balancing, scaling, and server maintenance.
It is possible to create mobile clients for App Engine backends
without Endpoints. However, using Endpoints makes this process easier
because it frees you from having to write wrappers to handle
communication with App Engine. The client libraries generated by
Endpoints allow you to simply make direct API calls.
Available in Python | Java

we have done similar thing for our Cordova/ionic based application. Its very simple and straight forward using javascript client of google cloud endpoint.

Related

What are the advantages of using Google Cloud Endpoints, explained in non-technical terms with examples?

I have previously used
#app.route('/mypage/<int:myvariable>/')
to create rules for what should happen when users land on different urls on my website. I have done this on local machines that have been running on my own virtual servers.
Now I am learning to publish my first web app to Google App Engine. I have heard that I should be using Google Cloud Endpoints instead of the route decorator.
#endpoints...
I've read a few articles about endpoints and some of the benefits of endpoints that they list are:
Endpoints makes it easier to create a web backend for web clients and mobile clients
Endpoints free you from having to write wrappers to handle communication with App Engine
Even if I have read this I can't wrap my head around what this means. I don't understand it. Can you explain in non-technical terms with examples what the advantages of using #endpoints is compared to alternatives? The alternative that I am familiar with is #app.route.
Google Cloud Endpoints can be thought of as a subset of #app.route. They are intended to solve the API backend problem for mobile and javascript clients. They are not intended to serve web pages and other hypermedia. You can use the normal routing methods of your framework of choice to create a web service for your application but Google Cloud Endpoints takes care of a lot of boilerplate for you.
There are a lot of limitations with Google Cloud Endpointsso be sure to familiarize yourself with them before committing. For one, you cannot host Google Cloud Endpoints on a custom domain name. They are only accessible via <app_id>.appspot.com/_ah/api/*
Endpoints makes it easier to create a web backend for web clients and
mobile clients
What this means is that you can create one backend and then iOS, Android and Web-apps (via Javascript for example), can execute your API methods with specific client generated libraries.
This is convenient if you are building a backend that you want to be easily accessed via smartphones or through a web browser.
Endpoints free you from having to write wrappers to handle
communication with App Engine
With Endpoints you can generate client libraries (e.g. Android, iOS, Javascript) that you can then execute your API methods. You don't have to worry about writing a bunch of additional code to do that.
My Opinion:
I have never used Cloud Endpoints to make a web-app but it is very convenient if you are making a mobile app for iOS and Android because you can access your backend with both platforms.
One reason you might want to use Cloud Endpoints for a web-app instead of something else is because of Datastore. Datastore is the way Cloud Endpoints stores data. It is a NoSQL storage method which is kinda tricky to wrap your head around at first if you come from a relational database background, but once you get it, it makes a lot of sense.

how to connect Google App Engine PaaS to DaaS

I want to connect my GAE Java project (Paas) to third party Cloud SQL (DaaS), I just want to know is it possible or not!
Details:
With my basic fundamental knowledge on J2EE I'm doing some hacks onGoogle App Engine (Java) PaaS, since Google cloud-sql for GAE is paid I want connect the GAE to any third party cloud SQL service (DaaS) like nuvola which offers free service for limited time period. Developers pain point is Google Cloud storage/ sql doesn't allow free space for developers unlike other platforms like Parse, kinvey etc will do.
update: URL Fetch API we can do that, I'm not sure it's the right way or not! also URL Fetch API Calls are Outgoing Bandwidth are billable!!
If you want to connect to external systems, the recommended way to integrate with them would be via Web Services.
You have 2 options:
Look out for a Web Service (typical REST with JSON/XML data) for your chosen data service provider in the cloud. You can then integrate your GAE app via URL Fetch API.
There is also a likelihood that your data provider also provides client libraries (Java, Python, etc) which you can easily integrate into your application. That would ease the integration.
App Engine also supports Sockets, but they are currently in Preview and available only for Paid Applications.

Google App Engine Backends not associated to any Frontend

I'm developing a Java app in GAE, which offers an API through Google Cloud Endpoints.
Basically it receives requests in the endpoints and uses a number of web services from different providers, stores some data and returns some data through the endpoints...
I understand that my app is conceptually a backend, because it doesn't provide any web page, but only the endpoints, don't you think so?
But there's no way to create only a backend, without being associated to any frontend app, is there? At least Google Plugin for Eclipse only allow you to "Generate App Engine Backend", from an existing app, and moreover this app must be an Android project...
I'm using it as a frontend and there's no problem, but apart from the conceptual issue, I've read that backends are kind of optimized to be backends, with more memory and CPU...
I think you're just confused because the Cloud Endpoints documentation uses the word 'backend' to refer to the entire cloud-hosted server implementation. It doesn't specifically refer to the use of GAE backend instances. Endpoint requests can be served by frontend or backend instances, based on how you set them up and the url being accessed.
From the App Ending docs:
"When an application is called to serve a web request, it must issue a response within 60 seconds"
"App Engine Backends are instances of your application that are exempt from request deadlines and have access to more memory (up to 1GB) and CPU (up to 4.8GHz) than normal instances."
So unless you're requests are doing something crazy, you don't need to use a backend. In the google-plugin-for-eclipse, "generate appengine backend" is talking about creating a backend for your android app... a server for your android app to contact (in this case your android app is the frontend and you're appengine app is the backend). In the example app you can remove the web side (index.html) to the appengine application and you'll have no web frontend. Index.html is using the gapi javascript library to make endpoints calls to your appengine service.

How to develop around Google API in GWT hosted mode?

I've been developing a GWT project which uses Google APIs authorized by the App Identity API. This way, I can authorize my application backend to exploit the APIs needing authorization (e.g. Calendar, Mail, etc). I want to keep control of the data, I don't want users to need their authorization for the personal data.
It is very useful to use the hosted mode to develop GWT apps. But as far as I know, you won’t be able to hit the real calendar API using OAuth while running in hosted mode because the GAE dev server doesn’t simulate the Application Identity API.
But how about the other APIs? Has anyone used this approach? Can I simply create a mock for the Identity API and work with Calendar Java API in hosted mode?
It is unclear to me how to work around this problem. Any help would be greatly appreciated.
How about you create a Calendar Stub class.
In case you are running in the production environment,
the Stub class calls the Google API using the App Identity API.
In case you are running in the developer environment,
the Stub class calls a secret handler in your production app,
which then calls the Google API using the App Identity API.
All you basically need to create is a proxy handler in your production app.
You can have a shared secret between the dev and the prod environment
and use https to communicate.

Does Google App Engine Support JAVA Proxy API's?

I have a question surrounding the REST service. I have an application written in C# , i want to put this application onto the cloud. I have a small problem, My Application has a built in C# API. I want to interact with my application and Google app engine. I want to develop a JAVA PROXY on top of GAE so that it can interact with my application using REST protocol and performs CRUD operations on Cloud and returns back data to my application.
Is it possible to do this ? to what i know is that SANDBOX feature doesn't allow us to directly interact with the App Engine.
Any suggestion on this.........
Thanks Heaps
Suraj
You don't need Java Proxy API in order to make http requests to another server (I guess you did not have java's Proxy class in mind?).
Yes, AppEngine can make HTTP/REST requests to other servers via URL Fetch java API.

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