Flash Forms
Flash Forms to the Rescue
The checkbox issue
Apr. 17, 2006 04:15 PM
Digg This!
Six months ago I was anxious to get the chance to upgrade our Web servers to Adobe ColdFusion MX 7 Enterprise Edition. During a product re-design, I realized how advantageous it would be for our customers to start using the new Flash Forms feature versus the standard HTML tables they had been using for years. The sorting and scrolling capabilities alone would be a hit.
Initially I thought that the Flash Forms would function like other HTML forms, but, as it turned out, there were some definite quirks to be dealt with. Fortunately I was able to resolve all the issues except one, which kept me stumped. I read up as much as possible online, using sites such as ASFusion.
The Problem
Our Web application had tables of data throughout the site. The first column of each table was always a checkbox so the user could check off whatever record he wanted to modify. The checkbox contained the primary key value for each of the records.
The issue with moving to Flash Forms was that there was no apparent checkbox-type functionality built-in. What needed to be done, to ASFusion's credit, was to introduce a new Bit column into the database table and show the column in the Flash Form as editable.
Here is some sample code that works well with Microsoft SQL Server.
Before:
SELECT *
FROM tblCustomers
<cfgridcolumn name='custID' display='no' />
<cfgridcolumn name='customerCode' header='Code' select='no' width='65' />
<cfgridcolumn name='username' header='Username' select='no' width='65' />
After:
SELECT *, checked=''
FROM tblCustomers
<cfgridcolumn name='checked' header="" type="boolean" width='25' />
<cfgridcolumn name='custID' display='no' />
<cfgridcolumn name='customerCode' header='Code' select='no' width='65' />
<cfgridcolumn name='username' header='Username' select='no' width='65' />
As you can see, cust ID is the hidden primary key column, and I added a cfgrid column called "checked" to reflect the new database column. By default none of the columns are checked since the SQL value for each column is empty. You'll also notice that none of the columns are selectable except the "checked" cfgrid column. That means the column can be checked on and off by the user just like the checkboxes before.
And I thought I was done.
The Problem (Continued)
What I found was that I could easily check off the record I wanted and get the custID to show on the other end. However, there was a problem. In HTML you can check and uncheck checkboxes and it returns a value only when the item is checked. In Flash Forms, when the item is essentially "touched," it becomes on. In other words, I would check a box, uncheck it, and submit the form, and it would show the custID of the one I checked and unchecked because Flash Forms thinks this record was "edited". This was going to be a problem. How was I to determine which item was "truly checked" versus which record was just "touched"?
The Solution
After checking around, I found myself alone in trying to find a solution. In essence what I needed was a piece of code that would parse through the submitted form fields and return the Primary Keys necessary for me to go about my work.
Here's a breakdown of the custom tag I developed to help resolve this issue. Note: This tag is in beta and will undergo some additional cleanup and should be posted on my blog soon.
The Custom Tag <!---
Problem: Flash Form Grids with CheckBoxes, when submitted, return all items that were checked AND unchecked, i.e. Edited.
Solution: getIDSelectedFromFlashFormGrid.cfm, with the user-specified hidden ID column name that's passed over via Flash Forms grid, cleans up the returned form scope, returning only IDs of the items that were truly selected.
Note: In Progress, works as is, Copyright Sami Hoda (c) 2005-06
Usage: <cf_getIDSelectedFromFlashFormGrid ID="**Primary Key Column Name **">
Output: variable listSelected, list of Primary Keys selected
--->
<CFSETTING ENABLECFOUTPUTONLY="YES">
<CFPARAM NAME="Attributes.ID" default="" type="string">
<!--- Checks to see how many checkboxes were 'touched' assuming checkboxes were named checked --->
<cfset numEdited = ArrayLen(GRID.checked)>
<!--- Clean form values by getting only values for 'GRID.*' and make a query of those values without the 'GRID.' prefix --->
<cfset newQ = queryNew("name,value")>
<cfloop collection="#form#" item="i" >
<cfif left(i,5) EQ "GRID." and left(i,13) NEQ "GRID.ORIGINAL" AND left(i,14) NEQ "GRID.ROWSTATUS">
<cfset temp = queryAddRow(newQ)>
<cfset wOutGrid = right(i, len(i) - 5)>
<cfset temp = QuerySetCell(newQ, "name", "#wOutGrid#")>
<cfset temp = QuerySetCell(newQ, "value", "#Evaluate(i)#")>
</cfif>
</cfloop>
<!--- Loops through the array values dependent on the number 'touched' and create a new proper query with simple values --->
<cfif numEdited GT 0>
<cfset newQQ = queryNew("ID")>
<cfset temp = queryAddRow(newQQ,numEdited)>
<cfloop index="z" from="1" to="#numEdited#" >
<cfset temp = QuerySetCell(newQQ, "ID", z,z)>
<cfset count = 1>
<cfloop query="newQ">
<cftry><cfset temp = queryAddColumn(newQQ, #newQ.name#, arrayNew(1))><cfcatch
type="any"></cfcatch></cftry>
<cfset foo = newQ.value[count]>
<cfset fooboo = foo[z]>
<cfset temp = QuerySetCell(newQQ,newQ.name, fooboo,z)>
<cfset count = count + 1>
</cfloop>
</cfloop>
</cfif>
<!--- Now, from the clean query, get only those who were truly selected, not just 'touched' --->
<cfquery dbtype="query" name="getSelected">
SELECT *
FROM newQQ
WHERE checked != 'false'
</cfquery>
<cfset myList = "">
<cfoutput query="getSelected">
<cfset myList = ListAppend(myList,#evaluate(Attributes.ID)#)>
</cfoutput>
<cfset caller.listSelected = myList>
<CFSETTING ENABLECFOUTPUTONLY="NO">
So, on my target page, I can write code like this:
<cfset numEdited = ArrayLen(GRID.checked)>
<cfif numEdited EQ 0>
<cflocation url="#errorURL#">
</cfif>
<cf_getIDSelectedFromFlashFormGrid ID="custID">
And now a variable called "listSelected" gives me a clean list of custIDs to use.
Some of the changes I have planned for the Custom Tag include:
- Naming the return variable
- Renaming variables for consistency
- Enhanced comments inside the code
- Enhanced error checking
- Speed enhancements
So I hope this shows how you can effectively use checkboxes inside Flash Form grids now.
About Sami HodaSami Hoda is an 11-year IT and Web development veteran with degrees in Computer Information Systems and Management & Human Resources. You'll find him reading profusely and passionate about best practices.