Documentation

HTTP Libraries

HTTP Libraries¶

Settings and Preferences
HTTP Libraries

Paw has the flexibility to send HTTP requests using different HTTP Libraries. This is mostly due to the limitations of Apple’s standard NSURLConnection library.

You can choose the HTTP library to use in menu Paw ‣ Preferences (⌘,), tab Network.

Paw HTTP Library¶

It’s the default library. It’s a custom HTTP library we built specifically for Paw, addressing the needs of a debugging tool. Built as an HTTP layer on top of GCDAsyncSocket (CocoaAsyncSocket), it allows Paw to show you exactly:

what will be sent to the server (in the Request Code Generator, Cmd+Shift+C to show/hide, then select HTTP)
what has been received from the server (in the Raw tab of the Response).

Warning: as the HTTP layer of this library is custom made for Paw, it hasn’t be as much tested over time than the 2 other ones. If you experience any problems, try to switch to another library it may fix it. However, please report any issue to the support, we want to hear from you and fix bugs asap!

Connection: close¶

To date, our custom HTTP layer does not support Keep-Alive connections. All connections are closed once the response is fully received. Also, the client sends a Connection: close header by default to make it explicit to the server.

Serialization & Parsing of the HTTP messages¶

To serialize (generate) and parse HTTP messages, it uses a custom made parser instead of the standard CFHTTPMessage.

ASIHTTPRequest¶

As its name suggests, it’s using ASIHTTPRequest which is a very well known HTTP library for iOS and OS X. Unfortunately, it’s now discontinued by the developer, which is one of the main reasons why it hasn’t been adopted as the default library for Paw.

Note that internally ASIHTTPRequest uses CFStream for the socket connection, and CFNetwork’s CFHTTPMessage to serialization and parse HTTP messages.

NSURLConnection¶

This is Apple’s default HTTP library.

Inaccurate Status Line¶

The main concern when using this library is that the HTTP Status Line returned by the server isn’t correct. This is a limitation of this library. Instead, Apple provides the standard status line matching the status code.

For example, if a server responds: HTTP/1.1 404 CANNOT FIND THIS PAGE, the status code shown will be 404 but the message will instead be NOT FOUND.

Comparison of the libraries¶

Default Headers¶

Header	Paw HTTP Library \| ASIHTTPRequest	NSURLConnection
Host	Set to the URL’s host. Port is added unless it’s 80 for HTTP or 443 for HTTPS. \| Set to match the URL	Set to match the URL
Connection	`close` \| Not documented	Not documented
User-Agent	`Paw 2.2 (Macintosh; Mac OS X 10.9.1; en_US)` \| `Paw 2.2 (Macintosh; Mac OS X 10.9.1; en_US)`	Not documented
Content-Length	Set to the length of what’s in the body \| Not documented	Not documented

For ASIHTTPRequest and NSURLConnection, some other headers may be sent.

Request Accuracy¶

Data	Paw HTTP Library	ASIHTTPRequest	NSURLConnection
URL	Accurate. Internationalized Domain Names and *URL Encode URL Paths option can change this behavior.*	Not documented	Not documented

Response Accuracy¶

Data	Paw HTTP Library	ASIHTTPRequest	NSURLConnection
HTTP Status Code	Accurate	Accurate	Accurate
HTTP Status Line	Accurate	Accurate	Does not match what your server sends. This shows the standard description matching the status code.
Headers with same name	Accurate: if multiple headers with the same name are sent, all are shown	Headers with same name are merged	Headers with same name are merged
Headers order	Accurate: order is maintained	Unknown order	Unknown order
Raw Response	Accurate	Artificially generated with other data	Artificially generated with other data