AJAX from PhoneGap - Cross-Domain Concerns? - ajax

I want to communicate via AJAX calls with a back-end server from a PhoneGap application.
Is there a way to associate the PhoneGap application with a domain that I own so that the requests don't all have to use CORS or JSONP?
If not, is it preferable to use CORS or JSONP for these AJAX requests from PhoneGap?

You do not need to be concerned about cross domain requests from a mobile device. They somehow don't matter. Your device can make requests to any site's JSON service just fine. If, however, you want to test locally on your PC prior to building and deploying to a device, you will need to use JSONP. I always use JSONP for that reason.

Related

How to deploy a js web app that fetches data from an api

How can I deploy a js web application that uses an API.
I have hosted it on netlify but it doesn't fetch the data.
Everything works fine on localhost.
Link: hiuhu-theatre.netlify.app
In firefox you can see the request the function getMovies made was blocked, the console shows the reason, it links to this URL.
Basically you're trying to use http protocol for that request when you're over https in your website.
To fix that simply change your "http://www.omdbapi.com/” to start with "https://" instead.
Also, if you can, do not add API key to client side code, if you do so anyone can steal it and use it themselves (and that might make you pay more for the service or reach the limit you have really quick), instead do a request to your back-end server so it fetches the data while hiding the API key.
It works in local because you're using http in local aswell.
I've overrided the getMovies function in my browser to use https and it worked nicely

Hosting two websites on same domain

I have two apps named opentripplanner-webapp and opentripplanner-api-webapp. I had successfully deployed them on local tomcat server. Apps has url as http://localhost:8080/opentripplanner-webapp and http://localhost:8080/opentripplanner-api-webapp. When i deployed apps on appfog , they give me different domains for both apps. The problems is that my apps use ajax request and responses which does not work on cross domains. I am searching for two days to find any solution but didn't find any suitable solution. Kindly guide me.
Thankss
Here's a couple of options for you:
Use JSONP (JSON with Padding). You would have to write your api so it supports this protocol, but it shouldn't prove too difficult.
Create both opentripplanner-webapp and opentripplanner-api-webapp so they support Cross Origin Resource Sharing. This means that your webapp sends an Origin header in the request, and the server responds with an Access-Control-Allow-Origin header, and if they match, the browser accepts the request. This is however not supported by all browsers, although most modern browsers do.
Use a proxy servlet in your opentripplanner-webapp that proxy requests to your API. You can "mount" this servlet at e.g. /api in the webapp, and it will forward all requests to opentripplanner-api-webapp internally. So you would send your AJAX requests to http://webappserver/api instead of http://apiserver. For the browser, this will look like an ordinary same origin request. This will work in all browsers, but might require some more setup.

What User-Agent to give my WebApi Requests?

I am using an api and I noticed that when I use RestSharp and do a call from my asp.net web api project my request fails.
I turned on fiddler and for whatever reason the api I am requesting thinks I am a mobile device and thus is redirecting me to the mobile site that does not support api calls.
I then did a request in fiddler and I can access the api. I changed my user-agent to fiddler through restsharp and now my requests go through when using my web api.
I don't want to leave it fiddler though. What should I use instead?
You are in-effect creating your own user-agent, so invent your own identifier. E.g. choboAgent/1.0

Deploying web app on HTTPS automatically makes my AJAX calls HTTPS too?

My application will be deployed on HTTPS (currently it is in development and running on HTTP).
Will deploying the web app on HTTPS automatically make my AJAX calls HTTPS as well? I am using relative URLs in the AJAX calls, so i am thinking that when the absolute URL is constructed, HTTPS will be appended automatically.
please let me know. thanks for your response
If you are using relative URLs, then yes.
However, it is really important to test this before running live, as certain browsers(at least IE6) will display a really alarming warning if you try to load resources like images using a non-https connection.

Accessing Web Services via AJAX?

Is it possible to directly access third party web services using Ajax? Mostly I've seen that the website I'm visiting handles it on its server and then transfers the processed/unprocessed data to client browser. Is this always the case?
(yes, almost always)
Typically, when you're trying to accomplish accessing third party web services a proxy server is used to access those services. You can't reach external third party web services because they exist on separate domains and you run into the "Same Origin Policy"
Now.... there are methods for doing cross-domain ajax, but the service you are accessing must support it (there are restrictions on what kinds of data can be returned and how the requests are formatted due to the way cross domain ajax works)
A simple way to do this is indeed by using some sort of server-side proxy for your request. It works like this. You do the Ajax request to your own domain, lets say proxy.php. proxy.php handles your request, forwards it to the 3rd party service and returns te results. This way you don't get the cross-domain errors. You can find multiple examples of these simple proxy's by using the magic Google.

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