Note:

The user interface has been simplified in Dreamweaver CC and later. As a result, you may not find some of the options described in this article in Dreamweaver CC and later. For more information, see this article.

About collecting information from users

You can use web forms or hypertext links to gather information from users, store that information in the server’s memory, and then use the information to create a dynamic response based on the user’s input. The most common tools for gathering user information are HTML forms and hypertext links.

HTML forms

Let you gather information from users and store it in the server’s memory. An HTML form can send the information either as form parameters or as URL parameters.

Hypertext links

Let you gather information from users and store it in the server’s memory. You specify a value (or values) to be submitted when a user clicks a link—a preference, for example—by appending the value to the URL specified in the anchor tag. When a user clicks the link, the browser sends the URL and the appended value to the server.

HTML form parameters

Form parameters are sent to the server by means of an HTML form using either the POST or GET method.

When using the POST method, parameters are sent to the web server as part of the document's header, and are not visible or accessible to anyone who's viewing the page using standard methods. The POST method should be used for values that affect database content (for example inserting, updating, or deleting records), or for values that are sent by email.

The GET method appends parameters to the requested URL. The parameters are in turn visible to anyone viewing the page. The GET method should be used for search forms.

You can use Dreamweaver to quickly design HTML forms that send form parameters to the server. Be aware of the method you use to transmit information from the browser to the server.

Form parameters take the names of their corresponding form objects. For example, if your form contains a text field named txtLastName, then the following form parameter is sent to the server when the user clicks the Submit button:

txtLastName=enteredvalue

In cases where a web application expects a precise parameter value (for example, when it performs an action based on one of several options), use a radio button, check box, or list/menu form object to control the values the user can submit. This prevents users from typing information incorrectly and causing an application error. The following example depicts a pop‑up menu form offering three choices:

Pop-up menu form
Pop-up menu form

Each menu choice corresponds to a hard-coded value that is submitted as a form parameter to the server. The List Values dialog box in the following example matches each list item to a value (Add, Update, or Delete):

List Values dialog box
List Values dialog box

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.

    URL parameters

You create URL parameters within an HTML link by using the href attribute of the HTML anchor tag. You can enter the URL parameters directly in the attribute in Code view (View > Code), or by appending the URL parameters at the end of the link URL in the Property inspector Link box.

In the following example, three links create a single URL parameter (action) with three possible values (Add, Update, and Delete). When the user clicks a link, a parameter value is sent to the server, and the requested action is performed.

<a href="http://www.mysite.com/index.cfm?action=Add">Add a record</a> 
<a href="http://www.mysite.com/index.cfm?action=Update">Update a record</a> 
<a href="http://www.mysite.com/index.cfm?action=Delete">Delete a record</a>

The Property inspector (Window > Properties) lets you create the same URL parameters by selecting the link and appending the URL parameter values at the end of the link URL in the Link box.

Property inspector
Property inspector

After a URL parameter is created, Dreamweaver can retrieve the value and use it in a web application. After defining the URL parameter in Dreamweaver, you can insert its value within a page.

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