Can you use a POST to GET data? - javascript

A company is asking me to do an Angular assignment. They provide the following instructions, but the API URL doesn't work:
Create a single page angular application and use the following API to retrieve sports results and sort into a table of results that are displayed. Each sport result contains several data and always includes the publication time.
Method: POST
Content-Type: application/json
Url: https://ancient-wood-1161.getsandbox.com:443/results
Tasks:
-Display the sports results in reverse chronological order on the page.
-Add a filter to the page to display only certain types or events (e.g. f1Results)
-How can you confirm the code works?
-Bonus: Implement the rest call asynchronously
You can click the URL https://ancient-wood-1161.getsandbox.com:443/results right now and see that it doesn't work - it returns {"errors":[{"message":"Error processing request"}]} and in Angular it gives me a standard CORS error.
I asked the company to please send a working URL and/or update the API to accept requests from everywhere. Their response was:
*guy's name* confirmed it worked. It is a post and the content type is json.
Can you use a POST request to GET data?

Absolutely. Take for example your avg Login Request that returns an access token for instance. It is going to be a POST as POST also has a bit more security than GET given that the payload is in the body rather than the URL string.
As for their excuse of it not working, try it in postman and see if the same issue still occurs. If it still does then ask them where did they test their API as if it is on prem then no duh the CORS would work. It is most likely not a company you would want to work for.

Yes, you can. On some cases it may be necessary, since GET doesn't take a body while POST does. So it can get you around things like URL length limits.

Related

I'm trying to send a JSON object from client to server and receive a response but all the approaches I find are either inadequate or overkill

I'm in a situation where I'm not sure what is the correct way of doing this. I'm trying to take a large json file, send it to the server, process and reorder it, and then send it back to the client. I don't want to store any data in a database. I know there's the HTTP GET verb, but the amount of data I would be inputting would be longer than the max length URI. I also read that you shouldn't try to do this with a HTTP POST either.
I looked into WebSockets as well but to me it appears to be overkill. I would only need the socket for the time that it takes to do the computations, then I would close it. Also I want to share the data with only the client who sent it to me.
Does any one have recommendations as for what to do. Maybe just a push in the right direction with a few links I can read. I'm really looking for something that runs down the middle of these two methods.
Why don't you just use a HTTP POST request? Taken from an info box on
https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST
> Request has body Yes
> Successful response has body Yes
> Safe No
> Idempotent No
> Cacheable Only if freshness information is included
> Allowed in HTML forms Yes
As you see, a HTTP POST request is used for sending data to the server, and if the POST request was successful, the server sends data back to the client. Perfect for your situation, I think.
A POST request doesn't have to be used within a HTML form; you could use XHR, AJAX, the fetch API, or any other way you can find to send the server a POST request. And yes, you could send JSON data with it.
If you need more convincing:
When the POST request is sent via a method other than an HTML form — like via an XMLHttpRequest — the body can take any type. As described in the HTTP 1.1 specification, POST is designed to allow a uniform method to cover the following functions:
Annotation of existing resources
Posting a message to a bulletin board, newsgroup, mailing list, or similar group of articles;
Adding a new user through a signup modal;
Providing a block of data, such as the result of submitting a form, to a data-handling process;
Extending a database through an append operation.
Notice that there, it said that a POST request can be used to provide a block of data to a data-handling process.
Hope this helps you. :)

How to use requests in Python 3 to fetch data from website that utilizes JavaScript and jQuery

I have been playing around with the requests library in Python 3 for quite some time now, and have decided to create a test program. For this program, I'm using the website https://ytmp3.cc/ as an example. But it turns out that a lot is going on, on the client-side it seems.
Some keys and other stuff are being generated, and I have been using Firefox's built-in network monitor, to figure out in which requests this is being made, but without luck.
As far as I know, the requests-library can't keep a "page" open and modify the DOM and content, by making more requests.
Anyone whom could take a look, and give a qualified guess on how the special keys are generated, and how I could possibly get these for my own requests.
Fx when loading the webpage, the first request made is for the root, and the response contains the webpage HTML. What I noticed is that at the bottom, there's an url containing some key and number.
<script id="cs" src="js/converter-1.0.js?o=7_1a-a&=_1519520467"></script>
id 7_1a-a
number _1519520467`
This is used for making the next request, but then a lot of following requests are being made, and some other keys are made as well. But I can't find where these come from since they are not returned by a request.
I know that when inserting a Youtube link, a request will be made to an url, as seen below.
https://d.ymcdn.cc/check.php?callback=jQuery33107639361236859977_1519520481166&v=eVD9j36Ke94&f=mp3&k=7_1a-a&_=1519520481168
This returns the following:
jQuery33107639361236859977_1519520481166({"sid":"21","hash":"2a6b2475b059101480f7f16f2dde67ac","title":"M\u00d8 - Kamikaze (Official Video)","ce":1,"error":""})
From this I can construct the download url, using the hash from above:
https://yyd.ymcdn.cc/ + 2a6b2475b059101480f7f16f2dde67ac (hash) + /eVD9j36Ke94 (youtube video id)
But how do I get
jQuery33107639361236859977_1519520481166&v=eVD9j36Ke94 and 1519520481168
Which I need to create the request?
You can probably save yourself and the operator of that website a lot of headache by just using youtube-dl, specifically with the --extract-audio --audio-format mp3 options. It's probably what that website itself uses.
youtube-dl is written in Python and can easily be used programatically.
If you insist on sending requests to that website for whatever reason, here's how I'd do it:
callback=jQuery33107639361236859977_1519520481166 specifies the name of the callback for the JSONP request. Any name you provide will be printed back out. For example, passing callback=foo will result in the following response:
foo({...})
You can omit it entirely and the server will serve just a JSON response in this case, which is nice.
_=1519520481168 is just to prevent the response being cached. It's randomly generated, just like the above parameter. The website checks for existence, however, so you have to at least pass something in.
The website, like many, checks for a valid Referer header.
Here's a minimal cURL command line to make a request to that website:
curl 'https://d.ymcdn.cc/check.php?v=eVD9j36Ke94&f=mp3&k=aZa4__&_=1' -H 'Referer: https://ytmp3.cc/'

Ajax query for JSON data not returning data

I'm trying to use World Bank's API to obtain some data. This is how to query their database. Basically to query a country's information, I would need to go to this url:
http://api.worldbank.org/countries/"alpha2Code of the country"
In my code here (Link to CodePen code.) I use use the alpha2Code from a previous query to add to the World Bank query's URL. Here's the method:
getDetails(alpha2Code) {
this.load('http://api.worldbank.org/countries/'+alpha2Code)
.then((countryDetails) => {
this.generateOverlay(countryDetails);
});
},
the load() method is defined here:
load(url, type = 'json') {
return $.ajax({
dataType: type,
url: url,
});
},
According to World Bank's basic calling format, I would need to add
format=json
in order to receive response in JSON. Somehow I don't think it's actually obtaining anything from WorldBank.
The query to World Bank is suppose to give me details to put into the overlay that covers the country flags after a click.
Thank you in advance for the help!
One issue with the CodePen you shared that may or may not be the problem with your site is that the CodePen demo is loaded over HTTPS, but you're requesting an insecure resource (HTTP). Browsers don't like this and will usually block it.
Unfortunately, you can't just change the request to be HTTPS since the WorldBank API doesn't have its certificates sorted out, so those requests are blocked by the browser as well. One solution would be to load your site over HTTP; however, this is obviously not advisable if your page contains any user-sensitive information.
The better way is to use your own back-end server as a proxy. You can setup your own API on your server that queries the WorldBank API over HTTP and can then respond to your request over HTTPS. Of course, this assumes you have control over your backend which is not always the case.
You need to pass the desired result format in the query. For example, to query INDIA, you would need to change the url to :
http://api.worldbank.org/countries/IN?format=json
The resulting data received is like:
[{"page":1,"pages":1,"per_page":"50","total":1},[{"id":"IND","iso2Code":"IN","name":"India","region":{"id":"SAS","value":"South Asia"},"adminregion":{"id":"SAS","value":"South Asia"},"incomeLevel":{"id":"LMC","value":"Lower middle income"},"lendingType":{"id":"IBD","value":"IBRD"},"capitalCity":"New Delhi","longitude":"77.225","latitude":"28.6353"}]]
The default output is in XML format. Hence your code may not be working.

HTML form seems to be submitting *both* POST and GET?

This is not a duplicate of questions such as this, but rather the opposite: I have a form that I'm submitting via jQuery
$('<form>', {
action : 'service',
method : 'post',
target : '_blank'
}).append(
$('<input>', {
type : 'hidden',
name : 'payload',
value : JSON.stringify(payload)
})
).appendTo('body').submit().remove();
This is done so that I can open a different page with HTML.
Since I need to submit quite a lot of complex information, what I actually do is serialize them all into a big JSON string, then create a form with only one field ("payload") and submit that.
The receiving end has a filter that goes like this:
if the method is POST,
and there is only one submitted variable,
and the name of that one variable is "payload",
then JSON-decode its value and use it to create fake GET data.
So when the GET data grows too much I can switch methods without modifying the actual script, which notices no changes at all.
It always worked until today.
What should happen
The server should receive a single POST submission, and open the appropriate response in a popup window.
What actually happens instead
The server does receive the correct POST submission...
...apparently ignores it...
...and immediately after that, the browser issues a GET with no parameters, and it is the result of that parameterless GET that gets (pardon the pun) displayed in the popup window.
Quite unsurprisingly, this is always a "You did not submit any parameters" error. Duh.
What I already did
verified that this method works, and has always worked for the last couple of years with different forms and different service endpoints
tried replacing the form with a hardcoded <FORM> in HTML, without any jQuery whatsoever. Same results. So, this is not a jQuery problem.
tried with different browsers (it would not have helped if it only worked on some browsers: I need to support most modern browsers. However, I checked. Luckily, this failure reproduces in all of them, even on iPhones).
tried sending few data (just "{ test: 0 }").
tried halting the endpoint script as soon as it receives anything.
checked Stack Overflow. I found what seems to be the same problem, in various flavours, but it's of little comfort. This one has an interesting gotcha but no, it does not help.
checked firewalls, proxies, adblockers and plugins (I'm now using plain vanilla Firefox).
called the IT guys and asked pointed questions about recent SVN commits. There were none.
What I did not yet do
Check the HTTPS conversation at low level (I don't have sufficient access).
Compared the configuration, step by step, of a server where this works and the new server where it does not.
Quite clearly, put my thinking hat on. There must be something obvious that I'm missing and I'm setting myself up for a sizeable facepalm.
Use a tool like hurl.it or Postman to manually send a request to the server. The tools will nicely display the response from the server including all HTTP headers. I suspect the server responds with a redirect (Status code 30X) which leads to a GET request being issued after the POST completes.
Update: HTTP redirects
HTTP redirects do not necessarily use the same HTTP method or even the same data to issue a request to the redirect target. Especially for non-idempotent requests this could be a security issue (you don't generally want your form submission to be automatically re-submitted to another address). However, HTTP gives you both options:
[...] For this reason, HTTP/1.1 (RFC 2616) added the new status codes 303 and 307 [...], with 303 mandating the change of request type to GET, and 307 preserving the request type as originally sent. Despite the greater clarity provided by this disambiguation, the 302 code is still employed in web frameworks to preserve compatibility with browsers that do not implement the HTTP/1.1 specification.
[from Wikipedia: HTTP 302]
Also for 301s:
If the 301 status code is received in response to a request of any type other than GET or HEAD, the client must ask the user before redirecting.
[from Wikipedia: HTTP 301]

How to map a custom URL to a REST resource in an SPA?

I have a design issue with my SPA, and hope someone can give me some direction. A user profile page is rendered like this:
The browser fetches /some-username.
The server checks to see if the request was a XMLHTTPRequest or not. It is not, and so it simply returns the bundled javascript app to the browser to execute.
The javascript bundle is executed in the browser, it sees the current URL and makes an AJAX request, again to /some-username.
The server sees the XMLHTTPRequest header, looks up the user who has the custom URL "/some-username" and returns the JSON data about the user back to the javascript to render.
This feels wrong. The app should be making RESTful requests to /users/:id to fetch the user data. But how can it know the id that corresponds to the user with the URL /some-username?
It is worth adding an extra HTTP request just to look up the resource identifier? Something like /get_user_id?url=/some-username.
Are you flexible about your API? If so you may change /some-username to /user-id or if you want to include username /user-id/username but ignore username.
As alternative it is also common to make requests in a filter form. Like /users?username=peter
And feel free to use /users/peter if your username identifies the user. Becuase it's actualy the id (that doesn't have to be integer) and then your url is exactly /users/:id
There is nothing "unRESTful" about /some-username. It's just another resource. The response - I hope - contains the canonical URL /user/id anyway, either as a header or as some kind of "self" link.
That's also how you could achieve your goal. Embed the URL in the page either as JavaScript or as a header equivalent (unfortunately you cannot read the headers of the page request with JavaScript):
//header. Can also use a custom header like X-User-Location
<meta http-eqiv="Location" content="/user/id">
//JavaScript
<script>
var userURL = '/user/id
</script>
I recommend keeping your current approach.

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