[FX.php List] Editing Checkboxes

[Derrick Fogle]

FYI, I get proper de-selection of checkboxes in an FM database  
without doing anything special in the PHP code. Here's how it works  
for me:

For any single-item checkbox in FM, I always use a number field, and  
the value is always either a 1 or nothing/null. Then I do an:

$instance -> AddDBParam('checkboxfield',$submittedcheckbox);

...in my PHP code for a record update. If the checkbox was previously  
checked and the user un-checked the box on the web form, it is true  
that the $submittedcheckbox variable does not even exist. But,  
setting the FM field to a non-existent variable really does set the  
field to nothing/null, rather than leaving the previous value.

It's only when I have a multi-value checkbox (which I usually stay  
away from) that the code becomes more difficult, but I've still never  
had to explicitly set a un-checked checkbox value to 0 or null to  
submit it to FM. Instead, just assemble the checked values into a  
return (\r) -delimited variable, and set the FM field to that  
variable. That should completely replace any existing values, not  
simply add to or change them.

I also recommend making sure any fields used for data input from PHP  
should not have any formatting (checkboxes, popup lists, etc.) at  
all. They should all be plain entry fields. You shouldn't need them  
because you're already using another interface (web form) to limit  
data input the same way as an FM checkbox or popup would.

Derrick Fogle
derrick at fogles.net