Lesson 1: Understanding forms CHAPTER 7 315■■Received The quantity of bytes transferred
■■Taken The time taken for the request
■■Initiator The trigger of the request
■■Timings A sequential timing chart that conveys a timeline of the requests
When the user types http://gjtt.com to navigate to this site, the first entry shows that the
result code of the request is 302, which is an indicator of a redirect. In this case, the redirect
was to http://www.gjtt.com/Pages/default.aspx. There are many HTTP return codes, which are
divided into categories based on the first of the three digits in the return code. The following
describes the categories of return status codes.
■■1xx Informational message
■■2xx Success
■■3xx Redirect
■■4xx Client error
■■5xx Server error
The second request is for the http://www.gjtt.com/Pages/default.aspx page, which returns a
result code of 200, indicating success. When the resulting HTML is returned from this request,
the HTML contains links to style sheets, which are consequently requested by the browser.
The HTML also contains images that are requested.Understanding the HTTP method
The HTTP method, which is also known as the HTTP verb, represents the command being sent
to the server. In Figure 7-3, all requests to the server used the GET method, which is used to
request a resource. The following is a list of the valid method values.
■■OPTIONS A request for information about the communication options available. This
method enables the browser to determine the options and requirements associated
with a resource without retrieving it.
■■GET equest to retrieve a resource such as an HTML file or an image file.A r
■■HEAD Operates like the GET method except that the server does not return a mes-
sage body in the response. The HEAD method retrieves metadata about a resource.
■■POST Request for the server to accept the data being sent from the client to modify
existing server data.
■■PUT Request for the server to accept the data being sent from the client to insert
new server data.
■■DELETE equest for the server to delete a specific resource.R
■■TRACE Invokes a remote, application-layer loopback of the request message, which
enables the client to see what the server is receiving. This is typically used for testing or
diagnostic information.Key
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