The GET Method
URL Encoding
- Besides allowing web browsers (or you
pretending to be one) to get documents from a web server, the
GET
method also implements a method for a web browser to send optional
search parameters as well (it was used with ISINDEX HTML files
originally).
- Search parameters were encoded in a
special way for processing by the web server.
- Here is how encoding works:
- The URL is differentiated from the first
search parameter by a question mark (?). In other words, a
URL
generically looks like the following:
http://www.domain.com/dir/file?search parameters
- Since you may want to have multiple
search parameters, the GET method specifies that parameters are
differentiated by placing an ampersand sign (&) between them.
Thus, the encoded URL above becomes something like the
following:
http://www.domain.com/dir/file?search1&search2&search3
- Next, search parameters themselves are
specified as "name/value pairs" separated by an equal sign (=)
such as in the following example that sets the variable "lname"
equal to "Sol" and the variable "fname" equal to
"Selena":
http://www.domain.com/dir/file?lname=Sol&fname=Selena
- Further, any spaces in the encoding
string are replaced by plus signs (+) as in the following
example:
http://www.domain.com/dir/file?name=Selena+Sol&age=28
- Finally, any non-alphanumeric characters
are replaced with their hexadecimal equivalents that are escaped
with the percent sign (%). For example, a single quote character
(') is encoded as %27 and a line break (which is a carriage
return plus a line feed) is encoded as %0D%0A. Thus, we might
see the following example that specifies that the variable
pageName is equal to "Selena Sol's Page":
http://www.domain.com/dir/file?pageName=Selena+Sol%27s+Page
Exercise One
Table of Contents
Problems With the GET Method
|
