Regarding to a static link on a web page, the browser will issue GET or POST request to the web site, depending on whether a form of parameters attached.
However, I want the browser to issue a PUT request for that link, how can I do that? I know that Ajax could do it, but I don't want to use Ajax.
I want the browser to issue a PUT request for that link
it seems that PUT and DELETE are currently unsupported in html forms, according to this submission to the w3.
I know that Ajax could do it
Not always true. Because PUT and DELETE are at times unsupported by some browsers, ajax cannot consume them without making a dummy param to trigger a real PUT or DELETE server side, which gives the illusion of full HTTP support by ajax.
Related
I'm trying to manipulate a .net ASP form on a site that's using AJAX Control Toolkit. The site is only accessible to valid logins, and I do have a valid account. It consists of a search page with a form. Each time a submit button is clicked on the form, the server is updated using the values of some text fields on the form, and then the VIEWSTATE and EVENTVALIDATION tokens will be updated based on the response from the server, ready for the next request.
I'm using HttpClient in Java to do this. I suspect there's something I'm not doing correctly with regard to interacting with ASPX forms in general.
When I hit the main search page for the first time (cookies are validating my login with the server), I get the HTML for the search page back. I extract the VIEWSTATE and EVENTVALIDATION tokens for the next request. I've examined the exact form fields and their values that need to be sent to the server in a POST by looking at the Chrome debugger utility after making a request on the site manually. I've replicated them exactly as they should be, inserting the VIEWSTATE and EVENTVALIDATION appropriately.
But the response I get back from the server is not what it should be. What I get back is just the same HTML for the main search page that I get the first time I hit the webpage. The form data I'm using looks like this:
ctl00$ScriptManager1:ctl00$ContentPlaceHolder1$UpdatePanel1|ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$acceptButton
ctl00_ContentPlaceHolder1_TabContainer1_ClientState:{"ActiveTabIndex":0,"TabState":[true,true]}
__EVENTTARGET:
__EVENTARGUMENT:
__LASTFOCUS:
__VIEWSTATE:<token extracted from first page hit>
__VIEWSTATEENCRYPTED:
__EVENTVALIDATION:<token extracted from first page hit>
ctl00$ContentPlaceHolder1$LabelFee:0
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$RadioButtonList1:Person
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$snameText:aSurname
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$HiddenField1:
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$fnameText:aFirstname
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$dayFromTextBox:01
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$monthFromTextBox:January
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$yearFromTextBox:2001
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$dayToTextBox:01
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$monthToTextBox:January
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$yearToTextBox:2008
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$DropDownList1:aCity
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$PropText:
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel2$RefText:
__ASYNCPOST:true
ctl00$ContentPlaceHolder1$TabContainer1$TabPanel1$acceptButton:Accept
I've also tried replicating the headers that the Chrome debugger shows, so my request is including the same Content-Type, Host, Origin, Referer, User-Agent (for my browser) and every other header, including this header X-MicrosoftAjax: Delta=true.
I know there's a lot of moving parts here, but I intentionally haven't mentioned how I'm actually making the POST request with the HttpClient lib because I'd don't want to complicate the question anymore or alienate anyone who doesn't know Java but knows ASP. I'd like to know if there's an ASP issue I'm not addressing, but I can post the Java code is necessary.
Edit:
I've checked the debugging info that HttpClient is outputting just before sending the request, and the form data is being added properly as multi-part form data. The headers are all there too.
This answer is a long shot, but I've seen weirder things.
You mention this header:
X-MicrosoftAjax: Delta=true
I did some deep googling and found that this is often shown as all lower case in dumps of Ajax and UpdatePanel POST requests:
x-microsoftajax: Delta=true
See here and here.
Could it be as simple as not casing the header correctly?
I eventually got this working. The problem was not specific to ASP in general, it was actually a problem with how Java (specifically HttpClient) was sending the request. I was using HttpClient to compile the request using multi-part form, but after using Fiddler to analyse and compare the requests (see the edited part of this question for more details on that) sent from both my application and the actual webpage, my app request was structured very differently.
The real website request had the form options embedded in the request body in what looked like a URL encoded query string. My request was a series of entries in the request body where each option was wrapped in the Content-Type and Content-Disposition headers. The requests succeeded after changing the POST to add the parameters like:
request.setEntity(new UrlEncodedFormEntity(paramList));
Regarding this question and also many documents have stated that sending a PUT request directly via form in browser is impossible due to security reason.
However, What I am seeing in Backbone is that it could still send a direct PUT request via browser without a workaround like adding a hidden form field.
And they're confusing to me. Is there anything that I'm missing here?
A form can only send a GET or a POST request, as set in the method attribute.
However, Backbone delegates its requests to jQuery.ajax by default (or whatever you want via Backbone.ajax) which itself wraps XMLHttpRequest, an object that can send PUT/DELETE/PATCH requests.
From https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest
XMLHttpRequest is a JavaScript object that was designed by Microsoft
and adopted by Mozilla, Apple, and Google. It's now being standardized
in the W3C. It provides an easy way to retrieve data from a URL
without having to do a full page refresh. A Web page can update just a
part of the page without disrupting what the user is doing.
XMLHttpRequest is used heavily in AJAX programming.
many documents have stated that sending a PUT request directly via browser is impossible due to security reason
Citation please.
Backbone sends a PUT just like it sends any other request, with jQuery,
Backbone.ajax({
type: 'PUT'
...
});
It is just some server side langauges,like PHP, that have problems with receiving a PUT request.
The hidden form field is used when posting from a <form>. Backbone uses javascript.
I have a standard html registration page that targets an external .asp page on submit.
What happens is that currently the .asp (which I don't have access to)returns an entire html page.
Instead I would like to somehow parse the returned html and populate the existing form with either
a) validation errors if incorrect
or
B) some sort of success message if all validated
Can anyone tell me if this is possible and or help with some pseudo code?
This is doable in JavaScript using ajax, but it requires that the ASP page (presumably on a different domain) sends appropriate CORS HTTP headers. Even if you don't have access to the actual ASP page, you may be able to get someone to setup the headers in IIS on their server.
Otherwise, you're stuck moving everything server-side, i.e. simulating the POST on your own webserver, and scraping the HTML to get the status back. That looks something like:
Postback the page to your own page (or use Ajax)
On your server, initiate a web request post of the data to the ASP page
Parse the results in your server code
Return an appropriate response to the browser client
The best you can do, assuming I'm interpreting your question correctly, is "scrape" the HTML returned from the asp page and make proper assumptions about the location and meaning of the text within the markup. I, personally, would strongly advise against developing anything of any kind of robustness based on what amounts to screen scraping, especially considering you don't have access to the .asp file itself. If I've misunderstood your problem, my apologies.
I want to silently check for Session existence without Posting back page by using AJAX Timer and AsyncPostBack Trigger.
Now, I would like to know is there anyway to silently check whether ASP.NET C# if (Session["email"] = null) { Response.Redirect("Logout.aspx"); } something of this kind to check for every 10 seconds without Posting Back Page and without using AJAX by using something like jQuery or any other technology that is supported by .NET?
The server can push to a loaded page if you use an asynchronous controller with a partial view which is loading every set amount of time.
http://msdn.microsoft.com/en-us/library/ee728598.aspx
there is only one way to get to the server. send a request. that can be a "standard" request where the browser will refresh the screen when a response is sent. the other type of request is a ajax request. the difference is an ajax request contains a header to inform the server it's an ajax request. when the browser receives the response it will allow the developer to decide what to do with the response. either way a full request/response exchange takes place the only difference is how the browser handles the request.
jquery is a javascript library that includes functionality to make ajax request easier to setup.
to answer you question no, there is no way around making a request.
In my asp.net application I have a some client side scripting that alters the page events and do different things. One problem I am having is when I post back to the server after all of the validation is done on the client side, I have a couple more validation checks on the server side (c#), and I want to show the proper error, but the page refreshes. I just would like to do some server side coding and if i need to go back to the page, go there as lasted viewed, with the error in the label, and changes i made on server side. Thanks for any help.
I think you must post it in ajaxy fashion.
I mean use ajax to post..
Evaluate the results on client side using JS.
Then if everything is fine do a redirect.
if errors exist you are still on that and can modify the html .
Do your server side validations in an AJAX call instead of a normal page post back. Because, you are making a background server call, your page does not refresh and on validation failure, you can retain the browser side UI. If validation is successful then you can do your regular post-back for actual processing.
From implementation perspective, you can use Page Methods (or JSON WCF services) in ASP.NET AJAX for the same: see this tutorial to get started with Page Methods: http://www.singingeels.com/Articles/Using_Page_Methods_in_ASPNET_AJAX.aspx