MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual

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Building drop-down list boxes 593
Reviewing the code
The following table describes the highlighted code and its function:
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_value
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
cfselect
is similar to the
HTML
select
tag. However,
cfselect
gives you more control over user inputs, provides error
handling, and, most importantly, allows you to 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
cfselect
is the same as for the HTML
option
tag.
When you populate a
cfselect
with data from a query, you only need to specify the name of the
query that is supplying data for the
cfselect
and the query column name for each list element to
display.
To populate a drop-down list box with query data using cfselect:
1
Create a ColdFusion page with the following content:
<cfquery name="getNames"
datasource="CompanyInfo">
SELECT * FROM Employee
</cfquery>
<cfform name="Form1" action="submit.cfm">
<cfselect name="employees"
query="getNames"
value="Emp_ID"
display="FirstName"
required="Yes"
multiple="Yes"
Code Description
href="http://
www.macromedia.com">
Makes the node of the tree a link.
href="http://
www.coldfusion.com">
Makes the node of the tree a link.
Although this example does not show it,
href
can refer to the name of
a column in a query if that query populates the tree item.