I am building a RESTful services using web api. My client is a HTML5/Jquery application. The service and application works perfectly on IIS 5.1. But when i switch to IIS 7.5, i see the response contains a Transfer-Encoding: chunked header and my client doesn't understand/render UI elements(btw this HTML 5/JQuery stuff is done by a third party and i don't want to change their code. why should i ? after all, it was working fine till we moved to IIS 7.5). My questions are :
How/Where do i add a "Conetent-Length" http header in web api so that IIS doesn't "chunk" encode the response?
Is there a way to disable this encoding at the site/server level in IIS 7.5 ?
When i access the service from browser/fiddler i get the proper response(xml/json). I am using Json.net formatter.
Use
myHttpResponseMessage.Headers.TransferEncodingChunked = false;
to turn off chunked encoding.
This could be due to this bug which is fixed post-beta:
"DevDiv 388456 -- WebHost should not use Transfer-Encoding chunked when content length is known"
http://aspnetwebstack.codeplex.com/SourceControl/changeset/changes/06f52b894414#src%2fSystem.Web.Http.WebHost%2fHttpControllerHandler.cs
Setting response.Headers.TransferEncodingChunked = false; didn't work around this issue for me.
Also you are likely to apparently be getting different results in Fiddler due to having "Decode" button pressed at the top which automatically de-chunks the response and removes the transfer-encoding header from the response.
Related
The format that all browsers accept:
https://user:password#my-site.com:8080
Is not working in fiddler 4.5. I get a DNS Lookup Failed.
I have to muck with headers and what have you...? Fiddler can't "just do the magic" ?
"All browsers accept" isn't true; this won't work with IE, Edge, Safari, and older versions of Firefox. Use of userinfo credentials in HTTP urls was disallowed by browsers and standards (e.g. RFC7230) because they were primarily used for phishing.
Fiddler 4.6.0.2's Composer will now automatically convert a HTTP url's userinfo to an Authorization header. For now, you could write FiddlerScript to pull the credentials from the URL and put them where they belong, but why not just do that to start with?
I have used a proxy tool to capture a certain REST HttpRequest. The request is a HTTP PUT command followed by an extremely long REST link containing specific data that gets sent to the server.
In the proxy tool it looks something like this:
Header
PUT http://XXX.XXX.XXX.XXX:8080/rest/blah/blah/.../ HTTP/1.1
Host: XXX.XXX.XXX.XXX:8080
User-Agent: Mozilla/5.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-language: en-us, en:q=0.5
Proxy Connection:keep-alive
Content-Type:XMLHttpRequest
Referer: http://XXX.XXX.XXX.XXX:8080/plugins/blah/blah
Content-length: 11156
Cookie: JSESSIONID=<really long alpha numeric>
Body:
{"links":{"self":"/rest/plugins/1.0/blah/blah.....
...
... lots and lots of JSON text
}
}
So the proxy tool has been helpful in identifying what the request looks like.
But the only way to generate this request is by clicking a button on the webpage. I would like to send exact same request on my own (like creating a custom link that when clicked generates a similar request to the one shown above). How do I do this?
Also, anything I type in the web browser URL area automatically is a "GET". How do I force a PUT?
Cookie: JSESSIONID=
This clearly indicates that the API you want to use is not a REST API, because it violates the stateless constraint of REST.
How do I force a PUT?
Probably you don't have a way to do that. It depends on the security settings of the web API. If you want to do this with AJAX from the browser, and your domain is different from the APIs domain, then you need a CORS header from the API, which allows your domain to read cross origin responses. By PUT the browsers sends a preflight first, and if it cannot read the response, it will never send the real PUT. Security policy and other headers can block XSS in the browser, so you probably don't have a way to do this from browser.
You can do this from your server by copying the request details and catching the session id somehow.
If the API allows access to 3rd party clients, then I suggest you to contact with them. If not, then you 99% that you won't be able to do this.
My restler 3 api works fine on local test server and works fine on production server if calls from that same server, but if I make the call remotely then it fails.
Using the same rest client with the luracast online examples it works fine with remote call so must be something in my configuration (either my api or my production server).
I found mention of need to send headers and so tried adding these headers to index.php file:
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: POST, GET, OPTIONS, PUT, PATCH, DELETE');
header('Access-Control-Max-Age: 1000');
header('Access-Control-Allow-Headers: *');
But that didn't help. Using RESTClient addon in firefox, I can see that those headers are sent, and the browser will show the data both locally and remotely, whether I use those header commands or not.
Here's a sample call:
https://api.masterpiecesolutions.org/v1/artists/?key=A4oxMOYEUSF9lwyeFuleug==
My index.php for that call uses this, with 2nd param to map to root level
$r->addAPIClass('Artists', '');
Don't know if that is relevant.
Also, the production server is Amazon EC2, so perhaps has something to do with security policy?
Or, maybe it's some other header issue? In google chrome, using Advanced Rest Client extension, it gives status of 403 Forbidden and Content-Type is text/plain (whether using local or remote server) so it won't work at all, unlike the firefox addon.
I also see use of $_SERVER['HTTP_ORIGIN'] in Restler.php, and this doesn't appear to be supported everywhere yet?
* is not a valid value for the Access-Control-Allow-Headers response header. You need to list out every non-simple request header. For example:
header('Access-Control-Allow-Headers: Content-Type');
Also consider putting a single origin value or just * for the Access-Control-Allow-Origin header. I just visited your sample url and there are multiple values in that header. Although this should work according to the CORS spec, it is not very widely adopted yet.
Lastly I noticed that the server was setting Access-Control-Allow-Credentials: true. If you set this to true, then you also need to do two other things:
The value of the Access-Control-Allow-Origin header must be the value of the Origin (e.g. http://localhost, it can not be *).
You will need to set xhr.withCredentials = true; in your JavaScript client code.
If you are just testing, you should try to get things working without setting the Access-Control-Allow-Credentials header. It will make things easier to debug.
The problem, for me at least, was using SSL and the restclient class didn't accommodate that.
So I added (to my RestClient.class.php from phpclasses.org)
curl_setopt($this->curl, CURLOPT_SSL_VERIFYPEER, false); // for SSL
and now it works.
Also required was setting
public static $crossOriginResourceSharing = true;
in Defaults.php for Restler 3.
I'm looking into a restful design and would like to use the HTTP methods (POST, GET, ...) and HTTP headers as much as possible. I already found out that the HTTP methods PUT and DELETE are not supported from the browser.
Now I'm looking to get different representations of the same resource and would like to do this by changing the Accept header of the request. Depending on this Accept header, the server can serve a different view on the same resource.
Problem is that I didn't find a way to tell my browser to change this header.
The <a..> tag has a type attribute, that can have a mime type, looked like a good candidate but the header was still the browser default (in Firefox it can be changed in about:config with the network.http.accept.default key).
I would partially disagree with Milan's suggestion of embedding the requested representation in the URI.
If anyhow possible, URIs should only be used for addressing resources and not for tunneling HTTP methods/verbs. Eventually, specific business action (edit, lock, etc.) could be embedded in the URI if create (POST) or update (PUT) alone do not serve the purpose:
POST http://shonzilla.com/orders/08/165;edit
In the case of requesting a particular representation in URI you would need to disrupt your URI design eventually making it uglier, mixing two distinct REST concepts in the same place (i.e. URI) and making it harder to generically process requests on the server-side. What Milan is suggesting and many are doing the same, incl. Flickr, is exactly this.
Instead, a more RESTful approach would be using a separate place to encode preferred representation by using Accept HTTP header which is used for content negotiation where client tells to the server which content types it can handle/process and server tries to fulfill client's request. This approach is a part of HTTP 1.1 standard, software compliant and supported by web browsers as well.
Compare this:
GET /orders/08/165.xml HTTP/1.1
or
GET /orders/08/165&format=xml HTTP/1.1
to this:
GET /orders/08/165 HTTP/1.1
Accept: application/xml
From a web browser you can request any content type by using setRequestHeader method of XMLHttpRequest object. For example:
function getOrder(year, yearlyOrderId, contentType) {
var client = new XMLHttpRequest();
client.open("GET", "/order/" + year + "/" + yearlyOrderId);
client.setRequestHeader("Accept", contentType);
client.send(orderDetails);
}
To sum it up: the address, i.e. the URI of a resource should be independent of its representation and XMLHttpRequest.setRequestHeader method allows you to request any representation using the Accept HTTP header.
Cheers!
Shonzilla
I was looking to do exactly the same thing (RESTful web service), and I stumbled upon this firefox addon, which lets you modify the accept headers (actually, any request headers) for requests. It works perfectly.
https://addons.mozilla.org/en-US/firefox/addon/967/
I don't think it's possible to do it in the way you are trying to do it.
Indication of the accepted data format is usually done through adding the extension to the resource name. So, if you have resource like
/resources/resource
and GET /resources/resource returns its HTML representation, to indicate that you want its XML representation instead, you can use following pattern:
/resources/resource.xml
You have to do the accepted content type determination magic on the server side, then.
Or use Javascript as James suggests.
ModHeader extension for Google Chrome, is also a good option. You can just set the Headers you want and just enter the URL in the browser, it will automatically take the headers from the extension when you hit the url. Only thing is, it will send headers for each and every URL you will hit so you have to disable or delete it after use.
Use some javascript!
xmlhttp=new XMLHttpRequest();
xmlhttp.open('PUT',http://www.mydomain.org/documents/standards/browsers/supportlist)
xmlhttp.send("page content goes here");
Why does using Fiddler break my site sometimes on page transitions.
After a server side redirect -- in the http response (as found in Fiddler) I get this:
Object moved
Object moved to here.
The site is an ASP.NET 1.1 / VB.NET 1.1 [sic] site.
Why doesnt Fiddler just go there for me? i dont get it.
I'm fine with this issue when developing but I'm worried that other proxy servers might cause this issue for 'real customers'. Im not even clear exactly what is going on.
That's actually what Response.Redirect does. It sends a 302 - Object moved response to the user-agent. The user-agent then automatically goes to the URL specified in the 302 response. If you need a real server-side redirect without round-tripping to the client, try Server.Transfer.
If you merely constructed the request using the request builder, you're not going to see Fiddler automatically follow the returned redirect.
In contrast, if you are using IE or another browser, it will generally check the redirect header and follow it.
For IE specifically, I believe there's a timing corner case where the browser will fail to follow the redirect in obscure situations. You can often fix this by clicking Tools / Fiddler Options, and enabling both the "Server" and "Client" socket reuse settings.
Thanks user15310, it works with Server.Transfer
Server.Transfer("newpage.aspx", true);
Firstly, transferring to another page using Server.Transfer conserves server resources. Instead of telling the browser to redirect, it simply changes the "focus" on the Web server and transfers the request. This means you don't get quite as many HTTP requests coming through, which therefore eases the pressure on your Web server and makes your applications run faster.
But watch out: because the "transfer" process can work on only those sites running on the server, you can't use Server.Transfer to send the user to an external site. Only Response.Redirect can do that.
Secondly, Server.Transfer maintains the original URL in the browser. This can really help streamline data entry techniques, although it may make for confusion when debugging.
That's not all: The Server.Transfer method also has a second parameter—"preserveForm". If you set this to True, using a statement such as Server.Transfer("WebForm2.aspx", True), the existing query string and any form variables will still be available to the page you are transferring to.
Read more here:
http://www.developer.com/net/asp/article.php/3299641/ServerTransfer-Vs-ResponseRedirect.htm