I know that there are two methods of submitting a form: 'GET' and 'POST'. We can also use request method for accessing the content of the submitted.
I want to know whether there is any other method of submitting the form. As far as my knowledge there are only two methods. But some one asked me this question in a interview that there are 5 method of submitting the form.
If any one has any idea about this please tell me.
The question was probably about HTTP request methods. There 9 request methods:
HTTP defines nine methods (sometimes referred to as "verbs")
indicating the desired action to be performed on the identified
resource. What this resource represents, whether pre-existing data or
data that is generated dynamically, depends on the implementation of
the server. Often, the resource corresponds to a file or the output of
an executable residing on the server.
HEAD: Asks for the response identical to the one that would
correspond to a GET request, but without the response body. This is
useful for retrieving meta-information written in response headers,
without having to transport the entire content.
GET: Requests a representation of the specified resource. Requests
using GET (and a few other HTTP methods) "SHOULD NOT have the
significance of taking an action other than retrieval". The W3C has
published guidance principles on this distinction, saying, "Web
application design should be informed by the above principles, but
also by the relevant limitations." See safe methods below.
POST: Submits data to be processed (e.g., from an HTML form) to
the identified resource. The data is included in the body of the
request. This may result in the creation of a new resource or the
updates of existing resources or both.
PUT: Uploads a representation of the specified resource.
DELETE: Deletes the specified resource.
TRACE: Echoes back the received request, so that a client can see
what (if any) changes or additions have been made by intermediate
servers.
OPTIONS: Returns the HTTP methods that the server supports for
specified URL. This can be used to check the functionality of a web
server by requesting '*' instead of a specific resource.
CONNECT: Converts the request connection to a transparent TCP/IP
tunnel, usually to facilitate SSL-encrypted communication (HTTPS)
through an unencrypted HTTP proxy.
PATCH: Is used to apply partial modifications to a resource.
HTTP servers are required to implement at least the GET and HEAD
methods
The HTML form element's method only accepts two parameters, GET and POST. Evidenced by this entry on the W3 Standards site:
method (GET|POST) GET -- HTTP method used to submit the form--
They may have been asking you about ways to submit the data. In which case there are many more, like AJAX, Flash, P2P types, etc.
However if they specifically said FORM, as in the HTML FORM element -- then no. POST and GET.
Addendum: Here is a StackOverflow question asked on a similar topic. In that the answerer highlights other methods which can be submitted via AJAX. Again, though, note that these are down through AJAX and not strictly through the FORM element.
Related
I'm creating a TODO list app with nodejs and I need an option to delete a todo record. So I've created an HTML form that contains a delete button but I can only use POST as the method. actually my code is working fine but are there any problems with using POST to DELETE records?
No there isn't. Apart from GET and POST requests, most of the other HTTP method serve only semantic purposes. Except for some notable examples such as OPTIONS which is use to communicate supported methods. Using correct HTTP verbs will make your application / API easier to understand.
The same goes for HTTP status code. Functionality-wise, it doesn't really matter if you send a 200 (OK), 201(Created), or 202 (Accepted) for a successful request. However, sending the correct status code can avoid necessary confusion.
As far as I know, no. There're no hazards of using HTTP post method instead of DELETE. You can see how it's used in deletion here
One difference is that users might be tricked into making the POST request and inadvertently deleting an entry, if they are lured onto a malicious web page that contains an auto-submitting HTML form
<form method="POST" action="<your deletion endpoint>">
(Whether that is possible depends on the content type that your deletion endpoint expects.)
A DELETE request, however, cannot be forged in such a way. A malicious web page could create a DELETE request only with fetch or XMLHttpRequest, and because of the CORS protocol the browser would refuse to carry that out (unless your server explicitly allows it through a suitable CORS preflight response).
I am trying to work with a service that its creators describe as "restful"
To make a request to this service I have to post some Json e.g.
{
"#type" : "Something"
"$value" : 1
}
This is posted to a URL similar to this;
https://someSite.com/api/query/execute
No matter what the nature of the request, whether I am retrieving info, adding or updating it I must always use this URL (along with some header values to verify my credentials). The effects of posting to this service are determined by the JSON I send.
Depending on the nature of the call I will receive some JSON very similar to the sample above. This JSON never includes another URL (or part of one). It is always a "data object" i.e. a set of properties and their values. Sometimes I receive an empty response but know that the request has had an effect because I can view those effects through a website provided by the service provider
I have particular issues with ENUM values that I must send because I have no idea of the allowed values (they are always passed as strings)
No documentation has been provided for this service.
I am relatively new to RESTful services and JSON and would like to know whether this is truly a restful service, and if not why not?
Due to my lack of experience in this area I may have omitted some important information that would be required to properly answer this question. I will watch the comments closely and try to provide any additional clarification requested
know whether this is truly a restful service, and if not why not?
It isn't.
One of the main principles of REST is that "things" are identified by URLs. Having a single URL for all interaction with the API violates that principle.
I am trying to stick to the Restful design pattern for both JSON and HTML. My issue is the design for creating a new resource (amongst others, but this is the gist of the issue). IE:
JSON – POST to /resource creates a new resource.
JSON – GET to /resource returns a list of resources.
JSON – GET to /resource/{id} returns a resource.
HTML – POST to /resource creates a new resource.
HTML – GET to /resource returns a list of resources.
HTML – GET to /resource/{id} returns a resource.
All good so far – but I need a HTML form to actually create the data to send to the HTML POST. Obviously POST and GET already do things. I could use one of the below to return the HTML form:
HTML – GET to /resource?CREATE
HTML - GET to /resource?action=CREATE
HTML – GET to /resources/CREATE
But they seem like a kludge and not that intuitive.
Any thoughts or ideas?
EDIT - See my answer to my question below. At present this is (I consider) the best option.
I would indeed use something like /resources/create. If you want to allow for non-numeric identifiers, then this will not work. In that case you can identify a resource with a prefix, such as /resources/resource-{id} and then you can still use /resources/create.
I found this blog post really helpful to make URI scheme decisions: http://blog.2partsmagic.com/restful-uri-design/
In fact, you should leverage content negotiation (CONNEG) when you want to handle several formats within RESTful services.
I mean:
Set the Content-Type header to specify the type of sent data
Set the Accept header to specify the type of data you want to receive
The server resources should leverage these hints to make the appropriate data conversion.
In the case of JSON, the content type would be obviously application/json. For HTML form, you should leverage the content type application/x-www-form-urlencoded (or multipart/form-data if you want to upload files as well). See the specification for more details.
Otherwise, you shouldn't use action in URL since it's not really RESTful. The HTTP verb should determine the action to do on the resource. I mean, to create a resource, the POST method should be used. The GET method aims to retrieve the state of a resource.
For more details, you could have a look at this blog post:
Designing a Web API (i.e. RESTful service).
I have an answer. I'll use standard RESTful POST from a HTML page, but when I have no form parameters sent and my accept header is text/html, I'll send a HTML form to the requestor. Keeps RESTful URI design and allows a clean HTML form + process (2 step).
HTML - POST - /resources (with no form attributes) generates a HTML form
HTML - POST - /resources (with form attributes) adds a resource
JSON - POST - /resources (with form attributes) adds a resource
OK, it's not "strictly" RESTful as I'm POSTing but not creating a new resource so in theory I should use a GET for that, but it's the best of a mismatched design.
If anyone can provide a better solution, I'm still all ears :-)
I'd rather add and endpoint called /templates/ that returns a template/form/whatever you need for given action. It also seems that the server should be unaware of such form existence. It can accept or reject a request and it's client job to submit it in an appropriate format.
I guess that you mix processing the view with preparing RESTful endpoints. The backend site should be completely unaware of the fact that some sort of view/form is required. It's client job to prepare such form.
I know differences and advantages of each command, my question is could I replace POST requests with GET everywhere? And which these commands calls by default while sending request from html form?
could I replace POST requests with GET everywhere
No (and it would be a terrible idea to try).
Things that a form can do with POST that you can't do with GET include:
Sending lots of data
Sending files
There are other things that would simply be stupid to do with GET.
From http://www.w3.org/TR/html5/forms.html#attr-fs-method :
The method and formmethod content attributes are enumerated attributes
with the following keywords and states:
The keyword get, mapping to the state GET, indicating the HTTP GET
method. The keyword post, mapping to the state POST, indicating the
HTTP POST method. The invalid value default for these attributes is
the GET state. (There is no missing value default.)
When using GET to transfer data from the client to the server, the data is added to the URL, there is not BODY of the request. There is usually a limit on how long a URL can be, in the old days this was 1024 characters but that really depends on the server software and server middleware and even the browser.
This means if you want to transfer loads or data or upload a file to the server, you can not do it with GET.
In regards to this Haacked blog, I'm hesitant to implement the proposed anti-JSON GET hijacking solutions since
The recommended solutions to mitigating JSON hijacking involve non-REST-full JSON POSTs to GET data
The alternate solution (object wrapping) causes problems with 3rd party controls I don't have source-code access to.
I can't find a community-vetted implementation that implements the Alternative Solution (listed below) on how to compose the security token, or securely deliver it within the webpage. I also won't claim to be enough of an expert to roll my own implementation.
Referrer headers can't be relied upon
Background
This blog describes a CSRF issue regarding JSON Hijacking and recommends using JSON POSTs to GET data. Since using a HTTP POST to GET data isn't very REST-full, I'd looking for a more RESTfull solution that enables REST actions per session, or per page.
Another mitigation technique is to wrap JSON data in an object as described here. I'm afraid this may just delay the issue, until another technique is found.
Alternative Implementation
To me, it seems natural to extend the use ASP.NET MVC's AntiForgeryToken with jQuery HTTP GETs for my JSON.
For example if I GET some sensitive data, according to the Haacked link above, the following code is vulnerable:
$.getJSON('[url]', { [parameters] }, function(json) {
// callback function code
});
I agree that it isn't RESTfull to GET data using the recommended POST workaround. My thought is to send a validation token in the URL. That way the CSRF-style attacker won't know the complete URL. Cached, or not cached, they won't be able to get the data.
Below are two examples of how a JSON GET query could be done. I'm not sure what implementation is most effective, but may guess that the first one is safer from errant proxies caching this data, thus making it vulnerable to an attacker.
http://localhost:54607/Home/AdminBalances/ENCODEDTOKEN-TOKEN-HERE
or
http://localhost:54607/Home/AdminBalances?ENCODEDTOKEN-TOKEN-HERE
... which might as well be MVC3's AntiForgeryToken, or a variant (see swt) thereof. This token would be set as an inline value on whatever URL format is chosen above.
Sample questions that prevent me from rolling my own solution
What URL format (above) would you use to validate the JSON GET (slash, questionmark, etc) Will a proxy respond to http://localhost:54607/Home/AdminBalances with http://localhost:54607/Home/AdminBalances?ENCODEDTOKEN-TOKEN-HERE data?
How would you deliver that encoded token to the webpage? Inline, or as a page variable?
How would you compose the token? Built in AntiforgeryToken, or by some other means?
The AntiForgeryToken uses a cookie. Would a backing cookie be used/needed in this case? HTTP Only? What about SSL in conjunction with HTTP Only?
How would you set your cache headers? Anything special for the Google Web Accelerator (for example)
What are the implications of just making the JSON request SSL?
Should the returned JSON array still be wrapped in an object just for safety's sake?
How will this solution interop with Microsoft's proposed templating and databinding features
The questions above are the reasons I'm not forging ahead and doing this myself. Not to mention there likely more questions I haven't thought of, and yet are a risk.
The Asp.net MVC AntiForgeryToken won't work through HTTP GET, because it relies on cookies which rely on HTTP POST (it uses the "Double Submit Cookies" technique described in the OWASP XSRF Prevention Cheat Sheet). You can also additionally protect the cookies sent to the client by setting the as httponly, so they cannot be spoofed via a script.
In this document you can find various techniques that can be used to prevent XSRF. It seems the you described would fall into the Approach 1. But we have a problem on how to retrieve the session on the server when using Ajax HTTP GET request since the cookies are not sent with the request. So you would also have to add a session identifier to you action's URL (aka. cookieless sessions, which are easier to hijack). So in order to perform an attack the attacker would only need to know the correct URL to perform the GET request.
Perhaps a good solution would be to store the session data using some key from the users SSL certificate (for example the certs thumb-print). This way only the owner of the SSL certificate could access his session. This way you don't need to use cookies and you don't need to send session identifiers via query string parameters.
Anyway, you will need to roll out your own XSRF protection if you don't want to use HTTP POST in Asp.net MVC.
I came to this problem and the solution was not so trivial however there is a fantastic blog to get you started this can be used with get and post ajax.
http://johan.driessen.se/posts/Updated-Anti-XSRF-Validation-for-ASP.NET-MVC-4-RC
If you place the following in the global name space all your post/gets can take advantage having an anti forgery token and you don't have to modify your ajax calls. Create an input element in a common page.
<form id="__AjaxAntiForgeryForm" action="#" method="post">#Html.AntiForgeryToken()</form>
The following javascript will read the anti forgery tokken and add it to the request header.
// Wire up the global jQuery ajaxSend event handler.
$(document).ajaxSend(namespace.ajax.globalSendHandler);
// <summary>
// Global handler for all ajax send events.
// </summary>
namespace.ajax.globalSendHandler = function (event, xhr, ajaxOptions) {
// Add the anti forgery token
xhr.setRequestHeader('__RequestVerificationToken', $("#__AjaxAntiForgeryForm input[name=__RequestVerificationToken]").val());
};
I think it is legitimate to use AntiforgeryToken (AFT) within an ajax http GET request provided that it is embedded in a form that already provides the AFT and associated cookie. The ajax handler can then do the validate on the server just how it would in a normal form post.