I'm creating an iPhone app and I want the app to be able to send some information in the form of JSON string over a web server/app (I really don't know) and display it in a web page or save it to a file. I know how to send the request from the iPhone, the problem is I don't have a clue on how to implement the server side and integrate it with a web page that can respond to the HTTP post I'm trying to send to it. I don't need any specific details so if you could only point me to the right direction e.g. reading material, websites, key technologies for this.
Thank you for your help
The general term for using JSON and HTTP is RESTful (actually that's not quite true, as REST doesn't technically mean JSON [though often it does!] and REST also includes other things, but it's still a good search term).
Here's a general set of links about the right kind of areas.
For python:
http://www.freenet.org.nz/dojo/pyjson/
For C#:
http://www.techbubbles.com/wcf/rest-based-wcf-service-in-aspnet-35/
For Java:
http://www.oracle.com/technetwork/articles/javase/index-137171.html
That should be enough to get you started; googling based on the various terms will throw up more articles. If you find any really good ones do add to your own answer!
Related
I'm trying to figure out what the latest best practice is when it comes to REST APIs and finding an elegant way to "tell" the client what the response will look like. I'm no web expert. But I just recently joined a new team and I've noticed that in the client code, they have hardcoded URI to APIs... and anytime the schema of the return data changes, they have to patch their client code.
Trying to find a way to make things more dynamic by:
introducing patterns to "discover" API servers.
looking into HATEOAS.
More than anything else though, what I'm trying improve is having to change the client code each time the logic on the server changes as far as the body of a GET response.
I've been reading this:
https://www.programmableweb.com/news/rest-api-design-put-type-content-type/2011/11/18
And in particular, the following comments stood out to me: (under the WRML heading)
this media type communicates, directly to clients, distinct and
complementary bits of information regarding the content of a message.
The Web Resource Modeling Language (WRML, www.wrml.org) provides this
"pluggable" media type to give rich web applications direct access to
structural information and format serialization code. The media type's
self-descriptive and pluggable design reduces the need for information
to be communicated out-of-band and then hard-coded by client
developers
Questions
is WRML still a thing? this book that i'm reading is from 2011... and I'm assuming a lot has changed since then.
Can I cheaply build my own inhouse solution where we use the Content-Type or some other header to provide the clients with schema information?
can you point me to an example / sample code where someone is using custom values in Content-Type or other Headers to accomplish something similar?
Or if you have any other suggestions I'm all ears.
Thank you.
I don't know much about WRML, but I would look into:
HATEOAS formats like HAL/HAL Forms and Siren, which are self-describing.
JSON-Schema to describe responses and requests (and yes they can be linked from HATEOAS responses).
If you don't want to go the hypermedia route, OpenAPI and RAML
I've been developing Ketting for the last 5 years and HATEOAS has been nothing short of magic lately as all the tools have been falling into place.
I'm new to web services world. I have created a rest api in ERP software that creates sales order. How will anyone outside the world know what parameters to send to this and in what format ? From all the videos I have watched and all materials read they talk about no api documentation is needed as it is REST service, People just know what request payload to send. I m not sure if I understand how that is possible. Its like I give somebody the url and tell them go figure. I tried sending orders with different parameter list and it is creating errors. But, if I send it in the way it accepts then it is working fine. Not sure if I understand the concepts well. Should I be creating documentation of this api telling what the request payload should look like ?
I completely disagree with the answer given by Joessel, which just propagates a typical RPC take on it, which is NOT REST at all!
In regards to how a service utilizing the REST architecture style should inform clients about what properties a resource supports and stuff like that, just look at traditional HTML pages. How are Web server able to tell your Browser what input it expects?
HTML is a media type that specifies the syntax to use as well as the semantics of each of the elements and attributes wich are admissible in a HTML document. I.e. HTML Forms enables a server to inform a client on the respective properties a resource support. In addition to that, a server also teaches a client on the respective target URI to send the request to, the HTTP operation to use upon sending the request as well as the media type to use for marshalling the request to a respective representation format. This is why you DON'T NEED any other documentation to interact with Web pages. Most arbitrary Web clients support HTML documents by default and therefore you don't need to reimplement the wheel to process such documents.
For non-HTML resources it is also just a matter of whether your client supports the respective media type or not. I.e. PNG files also follow a certain standard which allows arbitrary clients to show images instead of the actual bytes on your screen.
Most of those so called "REST APIs", which are truely RPC ones, just use custom JSON based message structures. JSON itself just defines the basic syntax but no semantics for any elements, attributes or other properties. It doesn't even add support for links. JSON Hyper-Schema is an extension which at least triest o add support for it, though it already requires to use an other media type than application/json. Though, if such formats are not well-defined and standardized, widespread adoption will not be possible on the long run. Hence creating a common media type is of importance to increase interoperability for such media types. I.e. for JSON based formats, HAL+JSON, HAL Forms, ION, and others provide definitions for basic JSON based message structures, with support for links and other features like form-support and other things.
So, if you take a closer look at the Web, you will find many concepts that you can reuse for a truely RESTful design. After all, REST just takes the ideas used on the Web for decades and attempts to offer the benefits resulting from these concepts to applications rather than humans alone. As such, it is always a good idea to first design the interaction flow as if one would interact with a traditional Web page and then take the concepts used in that design and apply it onto your application domain model.
As you don't need external documentation to interact with Web pages, so you don't need external documentation to interact with well defined message formats that follow a common media type as well. Through content-type negotiation both server and client will communicate with representation formats both support. So, the more (different) media types you support, the more likely you will be in the end to interact with different parties in that environment and if all of the supported media types are standardized you might not need any external documentation at all.
If you follow the academic definition of REST defined by Dr Fielding in his dissertation, it is true that such a service doesn't need any documentation. Hovewer, the chance are high that your service is not RESTful by his definition and that you need a documention to help your consumers. You can find an informative discussion about why a REST api doesn't need a documentation here.
That being said, you will probably need a documentation in most case. Depending on your needs and consumers of your api, a simple text file could be enough; maybe a markdown that you can easily share with other developers. Just remember to add all information needed to understand each route (verb, path, query, body, response...), and you can even throw some example code to make it easy to start.
And if you need something more robust, I can only advise you to follow the open api specification. One of the easiest way to get started is to use the swagger editor . You will even be able to publish your documentation in a nice way using one of the many tools out there (ex: redoc).
Writing a documention is never fun but nobody will use a product that they cannot understand, however great the product is.
Good luck,
Edit:
I rewrote the introduction as it was misleading, thanks to #Roman Vottner for pointing it out. THe previous intro was:
I don't know who told you that a documentation is not needed for a REST Api but I find this highly misleading for newcomers... A documentation is (super) important, especially if you are not the sole consumer of your API, and in that case I would say it's mandatory.
I am trying to create a RESTful web service that accepts JSON arguments and gives out a JSON response.
What I want is to accept HTTP requests made to my URL endpoint.
Something like,
POST /the/endpoint HTTP/1.1
Host: mywebsite.com
{"name":"yourname", "department":"your_department"}
Do a DB read at the backend and give relevant parameters like, say Manager name, salary etc as a JSON object, as the response.
What's the best way to go about it? I was thinking of using Java servlets for this? Is there a better way?
PS - I am just getting started so detailed answers or links to tutorials as to how to implement it would be much appreciated.
Thanks.
Yes you can easily do this with Servlets and some Json Libs for Marshalling /unmarshalling the Json Object to Java Object.
You can make use of Json libs like
Jackson ,
Gson etc
But you must know that REST application doesnt end with just handling the request and response , but it needs to take care of other non-functional requirements like
Authentication
Authorization
Security etc
Building this from a scratch from a Servlet is overkill and waste of time when there are ready made frameworks that these things for you
My favorite is Spring MVC 3.0
Check their project site for more details
Just to show you how easy to set up one in Spring MVC , check this below tutorial
Spring 3 REST Tutorial
Pls rate the post if it helps , Cheers.
If you want to go with Java, I suggest that you take a look at JAX-RS... And since REST is a complex topic, here is a url with tons of informations on it. http://code.google.com/p/implementing-rest/
As a complete beginner, I believe the best way to implement a (nearly) RESTful API without having to read a lot is simply to implement the API just using HTML pages and HTML forms with the back-end processing to handle them.
The rules are:
Use <a> tags to provide links to related resources. (navigation)
Use <form> tags to initiate any kind of processing operation on the server. (actions)
You can then make it properly RESTful by using progressive enhancement to add Javascript AJAX requests that perform PUT, PATCH, and DELETE instead of using POST for those three (of course, keeping POST for creating resources where the client doesn't know the resultant URI).
You can then click around and test the API in a web browser! Tools like Selenium can automate this.
If you need to provide JSON, this can be added after the API has been designed and tested, although libraries exist to process HTML or XHTML responses too, so JSON isn't necessarily required for machine readability.
if you are using php with symfony try:https://github.com/FriendsOfSymfony/FOSRestBundle this lets you create a real REST full servicer very quick.
Vogella made my day very easy when i started Web services with an super example here with eclipse screen shots ..Have a look here.
I have a web app, that also has an iPhone and Android app using the same API. It hasn't yet been made publicly available, so I wanted to look to convert from SOAP to REST.
I was only able to find a few tutorials that go into thorough explanations of how to code a REST web service, and of those I only found the MSDN one useful. The problem is I got really confused when they started using URI data types inside the object.
My question is, if you are converting SOAP to REST, do you have to recreate all the objects to add the URI? Am I not able to just have a REST entry point, then call one of the classes that retrieve the data?
Once the REST service is made it will only be used by my mobile apps, but not the website (since that can directly access the classes), which makes me not want to change the objects to add a URI. Is that a correct assumption to make, or should the web services also be called by the website?
Sorry if these are newbie questions, but I am struggling to get my head around REST, and I haven't had much experience creating the architecture of potentially high user base apps.
If anyone is able to point me to an actual code set, that would be helpful.
Edit: I am using VS2010, coding in C# and .Net 4.
Thanks a lot,
Andy
Im doing a very similar thing right now :). Rest via wcf isnt too hard, you do have to sometimes add your endpoints in the web config and give it the [webget]/[webinvoce] attributes in the refrence.cs of the web refrence when consuming though c# which is annoying.
Here is a code set i used when getting started. There are a few more on code project too.
I'm working on an iPhone project that needs to receive data from a PHP script during execution. My first thought was to use sockets/streams on either end to connect the two, but I am having trouble finding information on how to do this from the iPhone side.
Has anyone been down this path that could point me towards some useful resources or offer some advice? The official documentation seems to be geared more towards desktop apps and uses code that doesn't seem to be supported on the iPhone (namely NSHost).
Update: The intended use of this app is to receive log messages from an executing script, so I can't use a simple HTTP request with JSON or XML. Many cases will involve the page being loaded by another client, where the script would relay/push log messages to the iPhone.
Polling is evil. You'll chew through batteries doing that.
You might consider running an HTTP server on the iPhone. Check out this blog post; it has an implementation of an HTTP server in Cocoa as well as example code for using it for two-way communication.
The PHP CURL library (can't link it because the site doesn't trust me yet, just search php.net for it) is a (relatively) simple, easy way to make http requests with a PHP script.
Why don't you just use HTTP? Create an ad-hoc protocol with XML or JSON, use POST for upstream data transmission. I'm a fan of JSON for this sort of thing, personally. The PHP, instead of returning a webpage in HTML for rendering, should just return your data in a JSON format.