So far all the guides i have looked at involve communicating with a frontend client via Graphql, I wonder does it have any usage for something purely backend, such as communicating among microservices?
You can certainly make a request to the API from another server as well. Just as you can make a call to any REST endpoint from anywhere, you can perform server to server communication with GraphQL APIs as well.
For example, at Scaphold, we use Lambda for many webhooks and scheduled tasks. And from our microservice, we use the request library to make POST requests to the Scaphold server's GraphQL API.
Here's an example of a create mutation that you can use from a Node server.
Hope this helps!
Currently i working on Creating WCF service in order to communicate xamarin forms (Android) with sqlserver. For that i have tried some examples from the following link https://developer.xamarin.com/guides/xamarin-forms/web-services/consuming/wcf/ but it was not working also it throws error(SystemError).
My goal : i have to retrieve data from sqlserver using WCF service . Kindly provide ideas to solve this issues.
Thanks.
krupa
i think you want to create web-service, you can learn how to make wcf from here
webservices is same like an other client-server architecture where you send request to server and get response.
now make one hello world webservices base on above example
Request - in request you have to send data you can use xml or json
in method of webservice you have to process your data [calculate/store in DB/etc]
in response you send response data back
*to test a webservice use postman extension in chrome browser
This is really basic.I want to implement a RESTful web API.
Now I know you can write custom applications and scripts to integrate with the API.
What I need to know:
In what languages can you write this API? C#, Java, php?
When building/programming a program that implements this API, is this the client and the software that issued the API the server? (eg. Dropbox would be the server and the custom app that integrates with the Dropbox API is the Client?
Thank you.
A REST API can be built in any programming language that allows you to handle HTTP requests (or can be attached to a Web server as a handler for requests). The two methods I've been using:
Stand-alone Windows service implementing a REST service using WCF
WEB server Apache + PHP
You are correct about the terminology. A program consuming a service is called the client, a program providing a service is called the server (while actually in the PHP approach, Apache would be the server as it is taking the request and having the script handle it).
Additional nitpicking: JQuery is not a language, but a framework to help you use some JavaScript features more easily.
On your comment Recap:
Close :-) The Client transfers JSON/XML/whatever to a server using HTTP requests. The Client can be written in any language that can perform HTTP requests.
On the server side, there needs to be some application that handles the HTTP requests (service), also written in any language, as long as it "speaks" HTTP.
The API is the definition of which operations are possible, for example, adding user accounts, getting the current time, etc. (this is what you define - what do you want your service to do?).
The JSON/XML/whatever that you transfer is the workload, the parameters for the API call. For example, if you want to add a new user to your system, the workload could be the new user name, the real name, the eMail address and some other details about the user. If the API call returns the current server time, you might not need any parameters at all, but you get back JSON/XML/whatever from the service.
The actual call being made is determined by the URL you call. For example, the URL for adding a user could be http://localhost/myrestservice/adduser and you'd perform a POST request against that URL with the required workload. For the time example, the URL could be http://localhost/myrestservice/getservertime and you'd perform a GET request against that URL.
I suggest that you read about how REST services actually work before you start, as I see some question marks on your face ;-)
Short:
API = available operations (=> URLs)
Parameters to API calls = JSON/XML/Plain Text/whatever
Client = calls the service through HTTP
Service = handles the calls, replies to client in response to HTTP requests
If you are a php programmer and familiar with Codeigniter framework then go here : Working with RESTful Services in CodeIgniter.
visit also : Rest Tutorial
First of all, you should begin with learning what is a RESTful API.
http://en.wikipedia.org/wiki/Representational_state_transfer
http://www.restapitutorial.com/
http://rest.elkstein.org/
In what languages can you write this API? C#, Java, php, jQuery?
You can write an API in any language. What can help is the framework you'd be using. JQuery is not a language, but a framework for integrating Javascript application in every web browser, so it won't help.
I'd advice you to use a microframework to write your first RESTful API, because they usually are easy to use and help focus on the important (bottle/flask in python, express in javascript, silex in php, spark in java or nina in C#)
When building/programming a program that implements this API, is this the client and the software that issued the API the server? (eg. Dropbox would be the server and the custom app that integrates with the Dropbox API is the Client?
You're right, the server is providing you the service, hence the API. The client is user to that API, and implementing it into something useful.
As most of the people stated already, you can do this in just about any language.
Might I suggest that you look into NodeJS? If so, check out Restify: http://mcavage.github.io/node-restify/
There's a nice community behind NodeJS and I think it's quite open to newcomers. Just try not to pick up bad habits from JavaScript pitfalls. If you're new to programming, I'd suggest reading some intro book.
good luck!
First off I'm not too familiar with restlets , just starting out. I wanted to implement a broadcast chatroom where a client sending a message would have the message broadcast to all other clients.
My attempt was to use a resource on the server side where the client would send the message(as a String) using POST. The other clients would constantly have to poll this resource to receive the message. I know this method must be horribly ineffective.
I was wondering if there was a better method where a change on the server side(in this case the sending of the string message) would result in the server alerting the clients of this update.
Some things will come in version 2.1 with the new nio connector. Within web page, you might consider using technologies like Comet or HTML5 web sockets.
See the specification page from the developer wiki of Restlet: http://wiki.restlet.org/developers/172-restlet/g3/354-restlet.html
Thierry
Is this possible? I'm about to start into a project which requires a call from an SAP instance to a remotely hosted service using XML over HTTPS. Does anyone have sample ABAP code?
There is a SDN article titled "Real Web Services with REST and ICF". This covers the server side (providing a REST service) only, but maybe this could help you getting started. There's also the (arguably rather concise) documentation on client side ICF development. However, it looks like you'll have to parse the body on your own, using nothing but the XML support SAP provides you with. That's the drawback of REST...
This can be done using cl_http_client.
Check the SAP help documentation for the code.
For making HTTPS calls, you also need to import the certificate of your service provider into the system. This can be done using the transaction "STRUST". This step is compulsory; without it, you`ll get communication errors.