I'm developing an app heavly based on HTTP GET request to retreive user' data and choice, so i've decided to use Volley.
I've created a common RequestQueue for all the whole application and when I need a request I add a stringRequest to that queue.
The problem of mine is that some requests will be sended but other will not, I think that I've reached a max number of request or something similar, beacuse the stringRequest's URL is correct and writing it in my browser URL's bar I get data I want.
How can I solve this situation?
Related
I am currently trying to build a go API using gin for a web and mobile application. I am new to the world of WebSockets and Go so I was wondering how I would go about triggering a GET request from the client after a relevant POST request was made ie: the POST request contained the user's ID so the clients who require information regarding that user are properly updated. Currently, I have the POST and GET requests which do what I need them, but I'm a little lost about how to make the entire flow realtime using WebSockets.
I believe this example of server-sent-events should address the question. Once a POST handler has been called, send a flag to the GET endpoint via a channel and then send an event through there.
I am developing a simple website using MEAN stack that gives a logged-in user a task to complete and sends a score to the backend corresponding to their performance on that task. User can skip to next task in which case no score is sent. Problem is: How can I differentiate between a user cheating and sending score via a POST request on POSTMAN (by changing POST values to increase score) and a POST request created by my frontend code. How to work around this problem?
Welcome to Stackoverflow, to check if the request is made by POSTMAN (so locally) or by your backend (called by your front end) you just have to check if the request IP is your server or not.
This is a WhiteList solution
MEAN Stack use NodeJS, so you can use :
request.connection.remoteAddress
EDIT :
You can put a special parameter in your header when send a request with your front OR your Postman, and you check it when you receive it
From the client side, I am making an Ajax request of type "delete" using jquery.On the server side, I am doing res.redirect(URL).But instead of redirecting, browser is again making a delete request with URL returned from server side for redirecting.
However, it is not happening for a post request.Everything is OK with post request.
Short version
Ajax is trying to follow the request to it's bitter end to get a successful response (2xx). If you want to delete a resource and send the user to a new web page, you will need to handle that after receiving a success response from your Ajax call.
Full explanation
While redirects are sometimes used after processing a request (such as a successful / failed login) it's not really what they're intended for. Generally you would only redirect the user to get them to the resource their looking for. For example, you might move an endpoint such as POST /blog-post to the new location of POST /blog-article. What you're saying to the requester here is that something used to be where it is, but now they need to make a request elsewhere to find what they're after. This is incredibly important when trying to prevent link rot.
The idea of accepting and processing a request, and then moving the user off to another page is more of a coincidence really. It just happens to work due to how a browser handles URL requests.
I expect your POST request is actually using a form, in this case the browser is following the redirect because it received something like a 301 and is attempting to see a request chain through. However when using Ajax a redirect is being handled by the Ajax call itself, not the entire browser. Ajax in this case is acting as if you'd expect if the endpoint had been moved. So for example, if you moved the endpoint on the server side, your application would still function as it would follow the redirect instruction.
What you really need to do is return a successful response to your Ajax call such as a 204 (No content) and then in your frontend move the user on to a new page.
This isn't as convenient I'll admit, but when you understand why the redirects actually exist it makes more sense. They're not a way of telling a user to move onto something else, they're a way of trying to prevent link rot and enable applications to continue working against an API which may have changed slightly.
I know how to use ajax for submitting a form and all. What I am concerned about is, what is actually happening in the background when a form is submitted via ajax.
How are the values transferred? Encrypted or not? And what is the
need of specifying submission type, I mean get or post, if the URL is
not showing the form fields?
Edit: Found this on w3schools:
GET requests can be cached
GET requests remain in the browser history
GET requests can be bookmarked
GET requests should never be used when dealing with sensitive data
GET requests have length restrictions
GET requests should be used only to retrieve data
POST requests are never cached
POST requests do not remain in the browser history
POST requests cannot be bookmarked
POST requests have no restrictions on data length
How do these apply to ajax form submission?
Basically, when you Ajax-submit a form, it is doing exact same thing as what would happen when you as a user GET or POST submit a form - except that it is done in an asynchronous thread by the browser - i.e. called XMLHttpRequest.
If you submit form as a GET request, all of the form values are stitched together as parameter strings and appended to the URL (form's ACTION URL) - prefixed by a ?. This means anyone who can intercept that communication can read the submitted form data even if request is sent to a HTTPS URL. The POST method sends form data as a separate block (from the URL) and if URL is HTTPS then form data gets encrypted.
It looks like you are just starting out in the world of web development - welcome to the world of programming. I would recommend reading up on some good web development/programming books (I don't want to promote any particular book here). Amazon may help suggest few good ones under "Web Development" kind of search terms.
Also, I suggest that you read up a little on GET vs. POST by googling for it (I can only include one or two links - google will show you hundreds).
For the clear understanding & behind the scene things please refer the links given below.
http://www.jabet.com/
How does AJAX work?
Actually ajax request is same as the normal requests at the server end.
GET or POST has their own use cases. for example: GET has a limit of data transfer depending on the browsers from 1KB to 10 KB. where POST has no such limits.
For a server both AJAX & normal request both are same. so it depends on server code which method you wish to support.
ajax requests are NOT encrypted.
http://www.w3schools.com/tags/ref_httpmethods.asp
It looks like you want a very detailed answer so you can find it yourself:
Google it and read thoroughly the pages (wikipedia for example)
Read http://www.w3.org/TR/XMLHttpRequest/
Inspect the packets between your browser and the server
i have the following problem:
i need to send some custom info with every request made by a WebBrowser control. For example one of the infos is the used app version.
Now i have already read here that it is impossible to set custom headers for a WebBrowser control.
I have already tried to intercept all requests and perform them on my own with a WebClient (or HttpWebRequest). It partially works but is very buggy and often throws errors.
Any other ideas how to send the custom infos with every request that is made by the WebBrowser control?
Is the web server you are interacting with your own? Could you just add a query string parameter for all the data you want? Something like
http://yourwebsite/YourPage.aspx?version=2
Then you'd be able to process it on the server, either during that request in the aspx page, or via the logfiles for the web server.
I suspect that as you can't modify the content that gets sent directly from the WebBrowser and that intercepting every call and acting as a proxy for every request, while still maintaining all browser functionality may be too cumbersome.
Instead I'd suggest sending an additional request with just the additional information you want to record every time you make a request.
That could lead to a lot of overhead so it might be easier to send this once and then pass a hash of it, or some other identifying key to the webpage (as a querystring parameter) on the first request so it can reconcile the 2 pieces of information. Assuming that you are in control of the web server you could then have the web server set that hash/key as a cookie so it would be passed again with subsequent request from the control.