About HTTP and CSP

HTTP is a protocol used mostly for transferring web page content and XML between a server and a client. CSP is a platform-independent protocol based on the open standard of HTTP 1.1 that defines the syntax of communication between the portal and remote servers.

HTTP communication is made up of Requests and Responses. Requests and Responses are essentially lists of name-value pairs of metadata in headers, along with an optional body. The body is the data that is being transferred (an HTML page or XML file). The metadata in the headers is information about the Request or Response itself (what language the content is in, or how long the browser should cache it). The Request and Response each contain specific information, outlined next. For more detailed information on HTTP, see RFC 2616 (http://www.faqs.org/rfcs/rfc2616.html).

The client sends the server an HTTP Request, asking for content. The Request body is used only for requests that transfer data to the server, such as POST and PUT.

HTTP Request Format:

[METHOD] [REQUEST-URI] HTTP/[VERSION]
[fieldname1]: [field-value1]
[fieldname2]: [field-value2]
[request body, if any]

HTTP Request Example:

GET /index.html HTTP/1.1 
Host: www.plumtree.com 
User-Agent: Mozilla/3.0 (compatible; Opera/3.0; Windows 95/NT4) 
Accept: */* 
Cookie: username=JoeSmith

The server sends back an HTTP Response that contains page content and important details, such as the content type, when the document was last modified, and the server type. The Response contains an error message if the requested content is not found.

HTTP Response Format:

HTTP/[VERSION] [CODE] [TEXT] 
[fieldname1]: [field-value1] 
[fieldname2]: [field-value2] 
[response body, if any (document content here)]

HTTP Response Example:

HTTP/1.0 200 Found 
Last-modified: Thursday, 20-Nov-97 10:44:53 
Content-length: 6372 
Content-type: text/html 
<!DOCTYPE HTML PUBLIC '-//W3C//DTD HTML 3.2 Final// EN'><HTML> 
...followed by document content...

Custom HTTP headers can be configured to include specialized information.

Note: Header size limits are controlled by the server that hosts the code. The standard limit for IIS/ASP is 60K. Java Application Servers range from 2K to 10K. These limits are generally configurable; see your server documentation for details.

Services can also access standard HTTP headers, such as the Set-Cookie header or HTTP 1.1 basic authentication header. If you want to investigate HTTP further, you can view all the headers being passed back and forth between your browser and web server using a tunnel tool. HTTP is used in conjunction with SSL to serve up secure content. Single Sign-On (SSO) also uses HTTP headers for basic authentication.

CSP

CSP extends HTTP and defines proprietary headers to pass settings between the portal and remote server. CSP outlines how ALI services use HTTP to communicate and modify settings.

The current version is CSP 1.4, which includes backward compatibility with previous versions. CSP 1.2 is used in portal version 5.x. CSP 1.1 is used in portal version 4.5. Versions 4.x and below use CSP 1.0. For links to the latest versions of the CSP specification, see Additional Development References.

The IDK provides simplified, stable interfaces that allow you to write code that communicates using CSP.

ALI HeadersAquaLogic Interaction (ALI) portal uses a group of custom headers to communicate system and user configuration variables. These headers include information that can be used by services.
About SOAPSOAP is a text-based protocol to wrap XML data for any type of transport, providing an efficient way to communicate structured data.

Parent topic: About the ALUI Development Environment

AquaLogic User Interaction Development Guide

About HTTP and CSP

CSP