Is an API RESTful if it allows permanent requests (server push) - rest

I am writing a REST API providing CRUD operations on resources.
I'd like the users to be able to register to some resources changes and get the updates via server push. For the server push I will provide support for reverse ajax, hidden iframe and websockets. In order to be as REST as possible I created a Streaming resource which handles the registrations and the connection to the client:
Streaming resource:
URI uri : A GET against this URI refreshes the client representation of the resources accessible to this user.
bool WebSocket : Indicate if websocket is available on this server
bool ReverseXHR : Indicate if ReverseXHR is available on this server
bool HiddenIframe : Indicate if HiddenIframe is available on this server
Registration[] Registrations : The set of registration tasks.
OpenChannel : Open streaming channel from webserver to client. GET parameter type=(websocket|xhr|hiddeniframe)
CloseChannel : Close streaming channel from webserver to client. GET parameter type=(websocket|xhr|hiddeniframe)
A call of openchannel?type=websocket would open the websocket and start streaming the data of the registered values.
I've read many articles but I am still a bit confused. Can I still call my API REST after doing this? And if no (or yes) why?
Thank you for your help!

Firstly, always implement what makes sense to solve the problem you face. Conforming to a given architectural style provides specific benefits but this should not exclude pragmatic solutions to a given problem.
But having said that, it seems like you're using streaming of resource data as a way to "tunnel" information back & forth between the client and the server. I'm pretty new to this but it seems to me that the tunneling data goes against the uniform interface constraint in the REST architectural style. Tunneling over HTTP is one of criticism level against soap based services.

Related

Detect api changes flutter

Right now the app will need to detect whether a field from API got change or not
for example the api will return
{
successOrNot : false
}
when the field successOrNot become true, only then it will go to next page.
However the method that im doing right now is by using Timer.periodic, so it will call the api every 1 seconds, until the successOrNot become true then it will stop calling it. Is there another way on doing this since im afraid that it will affect the server because of api calling excessively.
You should use webSocket in this situation, sever will send message and client (flutter app) will listen to message from server, your current solution is ping the server by REST several times per minute, it maybe overloads the server in some case, e.g you have a lot of client but server resource is limited.
Link document about webSocket here: https://docs.flutter.dev/cookbook/networking/web-sockets
Beside websocket, you can also use SSE (Server Sent Events). But just like websockets, SSE require implementation on both server and client side. And depending on the situation both options may not be viable.

Listening to API changes in Flutter

assume I have an API that gives a JSON response that return an id and a name.
In a mobile application normally I would make an http GET response to get this data in a one time connection with the server and display the results in the app, however if the data changes over time and I want to keep listening to this data whenever it changes how is that possible ?
I have read about sockets and seen the socket_io_client and socket_io packages, but I did not get my head around it yet, is using sockets the only way to achieve this scenario ? or is it possible to do it in a normal http request ?
Thanks for your time
What you need is not an API but a Webhook:
An API can be used from an app to communicate with myapi.com. Through that communication, the API can List, Create, Edit or Delete items. The API needs to be given instructions, though.
Webhooks, on the other hand, are automated calls from myapi.com to an app. Those calls are triggered when a specific event happens on myapi.com. For example, if a new user signs up on myapi.com, the automated call may be configured to ask the app to add a new item to a list.
is using sockets the only way to achieve this scenario ? or is it possible to do it in a normal http request ?
Sockets is only one of the ways to achieve your goal. It is possible to do it using a normal http request. Here, for example, the docs explain how to update data over the internet using HTTP.
From the flutter docs:
In addition to normal HTTP requests, you can connect to servers using WebSockets. WebSockets allow for two-way communication with a server without polling.
You'll find what you need under the networking section.
You should also take a look at the Stream and StreamBuilder classes.

What is the purpose of having one endpoint for the whole app?

I'm building a web app with Laravel for scheduling emails and when I was checking out the competitors, I noticed that one of them is using only one endpoint for all the requests and sending different payload in the POST request.
I thought of building my app's API the same way but I really don't find the use of this point.
I noticed that one of them is using only one endpoint for all the requests and sending different payload in the POST request.
It's a common approach to use when you want transport agnostic messaging. See, for example, SOAP.

How to protect an API endpoint for reporting client-side JS errors against spam (if even necessary)?

I am developing a web application with Spring Boot and a React.js SPA, but my question is not specific to those libraries/frameworks, as i assume reporting client-side JS errors to the server (for logging and analyzing) must be a common operation for many modern web applications.
So, suppose we have a JS client application that catches an error and a REST endpoint /errors that takes a JSON object holding the relevant information about what happened. The client app sends the data to the server, it gets stored in a database (or whatever) and everyone's happy, right?
Now I am not, really. Because now I have an open (as in allowing unauthenticated create/write operations) API endpoint everyone with just a little knowledge could easily spam.
I might validate the structure of JSON data the endpoint accepts, but that doesn't really solve the problem.
In questions like "Open REST API attached to a database- what stops a bad actor spamming my db?" or "Secure Rest-Service before user authentification", there are suggestions such as:
access quotas (but I don't want to save IPs or anything to identify clients)
Captchas (useless for error reporting, obviously)
e-mail verification (same, just imagine that)
So my questions are:
Is there an elegant, commonly used strategy to secure such an endpoint?
Would a lightweight solution like validating the structure of the data be enough in practice?
Is all this even necessary? After all I won't advertise my error handling API endpoint with a banner in the app...
I’ve seen it done three different ways…
Assuming you are using OAuth 2 to secure your API. Stand up two
error endpoints.
For a logged in user, if an errors occurs you would
hit the /error endpoint, and would authenticate using the existing
user auth token.
For a visitor, you can expose a /clientError (or
named in a way that makes sense to you) endpoint that takes the
client_credentials token for the client app.
Secure the /error endpoint using an api key that would be scope for
access to the error endpoint only.
This key would be specific to the
client and would be pass in the header.
Use a 3rd party tool such as Raygun.io, or any APM tool, such as New Relic.

CORS , REST, XMLHTTP and HTTP

REST and CORS.. how are they different? is it even correct to compare them? because I have seen a seemingly REST API use custom X- headers to make a pre-flighted request(Docebo LMS API). This means that maybe CORS and REST are used for different purposes.. But on the surface, it seems that both are designed to give access to resources stored on a different server. Also, Simple XMLHTTP requests seem to work like HTTP.(The headers sent and received by the browser are through HTTP).. So, are XMLHTTP objects translated into HTTP by the browser? I am really taking in a ton of information right now and I cant seem to make any real progress in understanding these things... Any help is appreciated.
CORS - Cross Origin Resource Sharing. A concept and set of techniques that enables sharing of resource/data across domains. Example, from your page /yourDomain.net you try to make an ajax call to myDomain.net to post some data. Read this Wikipedia and MDN articles.
REST - REpresentational State Transfer. A set of standards & guidelines that defines a specific way for systems to talk to each other. It follows state-less http like standards where URIs reprsent resource and client can work on them using http verbs. e.g. GET weatherApp.com/weather/rome. Refer this.
HTTP - Hyper Text Transfer Protocol. THE standard protocol to transfer data to/from web servers. Check this W3 specifications and Wikipedia page.
XMLHttp - A type of request generally used to make ajax calls from client (mainly html, javascript) applications to web servers. It works on http standards. Not bound to XML though. Read this and this.
Now, all of REST, XMLHttp, CORS work on HTTP is some way, meaning they all use the http infrastructure.
And any/all of them might be used to create a fully functional modern application. For example, a web application might use XMLHttp request to make REST service call to get some data. It can also utilize CORS to get/post data to another domain. Need not say, the whole system relies on http!
They are totally different things. Rest is a specifical approach to prrforming data calls. Basically is characterized by a systen where the state is not stored on the server but rather passed in calls. You can read more here
Cors is a technique for enabling javascript to perform data ervice calls to domains otheir than the server donain that they came from. Normally web browsers prevent javascript and other web technologies from doing cross origin or cross domain calls. These are calls where a js script came from google.com lets say, and now it wats to call microsoft.com. well the browser would stop that call because google.com and microsoft.com are different domains.
That example is obvious, so lets try a less obvious one. Your script on blogs.yoursite.com tries to call a service at shopping.yoursite.com. now these sires are both yoursite.com but they could still be considered cross domain and usually are. CORS allows you(on the html developer side) to say i trust these domains. And by trusting them, now you can call their webservices even if they would have been a cross domain call.