Adobe Dreamweaver CC 2015 - Manual (Page 613)

606
Dynamic sites, pages and web forms
Last updated 6/3/2015
After a form parameter is created, Dreamweaver can retrieve the value and use it in a web application. After defining
the form parameter in Dreamweaver, you can insert its value within a page.
URL parameters
URL parameters let you pass user-supplied information from the browser to the server. When a server receives a
request and parameters are appended to the URL of the request, the server gives the requested page access to the
parameters before serving that page to the browser.
A URL parameter is a name-value pair appended to a URL. The parameter begins with a question mark (?) and takes
the form name=value. If more than one URL parameter exists, each parameter is separated by an ampersand (&). The
following example shows a URL parameter with two name-value pairs:
http://server/path/document?name1=value1&name2=value2
In this example workflow, the application is a web-based storefront. Because the developers of the site want to reach the
widest possible audience, the site is designed to support foreign currencies. When users log in to the site, they can select
the currency in which to view the prices of the available items.
1 The browser requests the report.cfm page from the server. The request includes the URL parameter
Currency="euro". The Currency="euro" variable specifies that all monetary amounts retrieved be displayed as the
European Union euro.
2 The server temporarily stores the URL parameter in memory.
3 The report.cfm page uses the parameter to retrieve the cost of items in euros. These monetary amounts can either
be stored in a database table of different currencies, or converted from a single currency associated with each item
(any currency supported by the application).
4 The server sends the report.cfm page to the browser and displays the value of items in the requested currency. When
this user ends the session, the server clears the value of the URL parameter, freeing server memory to hold new user
requests.
URL parameters are also created when the HTTP GET method is used in conjunction with an HTML form. The
GET method specifies that the parameter value be appended to the URL request when the form is submitted.
Typical uses of URL parameters include personalizing websites based on user preferences. For example, a URL
parameter consisting of a user name and password can be used to authenticate a user, displaying only information
that user has subscribed to. Common examples of this include financial websites that display individual stock prices
based on stock market symbols the user has previously chosen. Web application developers commonly use URL
parameters to pass values to variables within applications. For example, you could pass search terms to SQL
variables in a web application to generate search results.