Setting and Retrieving Control Values:
Sometimes it is necessary to set
or get the value of a control within an event such as the Before Show event
of the field or one of the events that occur after a record form is submitted.
For instance, if you have a Label control in a grid and want to alter the appearance
of its corresponding database value before it is displayed, you can use the
Retrieve Value for Control action within the Before Show event of the
Label field:
When you add a Retrieve Value
for Control action, you are required to specify three properties:
Control Name: The name of
the control whose value is to be set
Source Type: The method
to be used to set the control value
Source Name: The variable
or expression that contains the new value
In this example, we want to add some
text to the database value. As such, the Source Type property is set
to Expression. For the Source Name, we enter an expression containing
the text to be appended i.e. for ASP the Source Name property is set
to:
“Database Value is: ” & FormName.FieldName.Value
and for
PHP the Source Name property is set to:
“Database Value is:
” . $FormName->FieldName->GetValue();
In the above code, FormName and FieldName
should be replaced with the names of the form and field respectively.
The Retrieve Value for Control
action has a partner action called the Save Control Value which can be
used to extract the current value of a control. When you add a Save Control
Value action to an event such as the Before Show event of the field or one
of the events that occur after a record form is submitted, you are required
to specify the same three properties as was done with the Retrieve Value
for Control action. So for instance if we want to save the value of a control
into a variable called myVar, you would set the Source Type property to Variable
and the Source Name to myVar. The code
generated for the action would be:
‘ASP
myVar = FormName.FieldName.Value
‘PHP
global $FormName;
global $myVar;
$myVar
= $FormName->FieldName->GetValue();
Where FormName and FieldName
are the names of the form and field respectively.
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