User Guide

642 Chapter 27: Building Dynamic Forms with cfform Tags
Specifying the tree item in the URL
When a user clicks on a tree item to link to a URL, the
cftreeItemKey variable, which identifies
the selected value, is appended to the URL in the following form:
http://myserver.com?CFTREEITEMKEY=selected_item_value_attribute
If the value attribute includes spaces, ColdFusion replaces the spaces with plus characters (+).
Automatically passing the name of the selected tree item as part of the URL makes it easy to
implement a basic “drill down” application that displays additional information based on the
selection. For example, if the specified URL is another ColdFusion page, it can access the selected
value as the variable
URL.CFTREEITEMKEY.
To disable this behavior, set the
appendkey attribute in the cftree tag to No.
Building drop-down list boxes
The drop-down list box that you can create in a cfform tag with a cfselect tag is similar to the
HTML
select tag. However, the cfselect tag gives you more control over user inputs, provides
error handling, and, most importantly, lets you automatically populate the selection list from a
query.
You can populate the drop-down list box from a query, or using lists of option elements created by
the
option tag. The syntax for the option tag with the cfselect tag is the same as for the
HTML
option tag.
When you populate a
cfselect tag with data from a query, you only need to specify the name of
the query that is supplying data for the
cfselect tag and the query column name for each list
element to display.
To populate a drop-down list box with query data using the cfselect tag:
1. Create a ColdFusion page with the following content:
<cfquery name="getNames"
datasource="cfdocexamples">
SELECT * FROM Employee
</cfquery>
<cfform name="Form1" action="submit.cfm">
<cfselect name="employees"
query="getNames"
value="Emp_ID"
display="FirstName"
required="Yes"
multiple="Yes"
size="8">
</cfselect>
<br><input type="Submit" value="Submit">
</cfform>