Coding Considerations

Getting Results

Every time you use a CNS Barcode function, status text is returned back from the plug-in. This information can be very useful for letting you know if an error occurred. Consider the following code:

CNSBC_AddProfile ( "Scan Widget" )

The above code will add a profile named "Scan Widget". If it was successful, the plug-in will return:

Profile 'Scan Widget' Added.

However, if there was an error with the Profile Name (for example, it was blank), the plug-in will return something like:

ERROR: AddProfile: You must specify the Name for the new Profile ('ProfileName' parameter).

Curly Brackets

Curly brackets indicate that a parameter or parameters are optional. Take the CNSBC_ConfigureProfile function for example:

CNSBC_ConfigureProfile{( ProfileName )}

This function can be called without any parameters because the parameter section is surrounded by curly brackets indicating that is it optional. Using the function in this manner looks like:

CNSBC_ConfigureProfile

The above code would open the Profile Configuration Dialog and allow you to select any Profile for editing from a list. However, if you would like to only allow editing of a specific Profile, you can specify the name of that Profile in the optional "ProfileName" parameter:

CNSBC_ConfigureProfile( "Scan Widget" )

As shown above, make sure you remove the curly brackets or FileMaker will give you an error.

In more complex functions, there may be multiple optional parameters. Note that if there are optional parameters before one that you need to use, you must include any parameters before it. Consider the CNSBC_ScanWindow function:

CNSBC_ScanWindow( Action {; ProfileName {; Left {; Top {; WindowTitle }}}} )

If you want to specify the "WindowTitle" parameter, you must also specify the three optional parameters before it. Following is an incorrect example and a correct example:

INCORRECT: CNSBC_ScanWindow( "Show"; "Please scan a barcode" )
CORRECT: CNSBC_ScanWindow( "Show"; "Scan Widget"; "-1"; "-1"; "Please scan a barcode" )

FileMaker Version Considerations

When plug-ins were first introduced, the only place you really wanted to use a plug-in function was the Set Field script step. However, since FileMaker 4, many new advancements have taken place. Though the Set Field script step is still a very common place to use plug-in functions, there are now many places that can logically be used. For a list of a few of these places, see the next section titled "Places to use CNS Barcode Functions".

It is important to keep in mind what versions of FileMaker will be in use when using CNS Barcode and other plug-ins. For example, creating a variable using the Set Variable script step can be very convenient, however, that functionality only exists in FileMaker 8 and greater. If you or your users use FileMaker 7, then your script calls would fall on deaf ears if you used Set Variable script step. In addition, when using functions in a variable you will be less likely to see the results returned from the plug-in (such as error messages), because a variable cannot but put on a layout like a field.

Places to use CNS Barcode Functions

You can use CNS Barcode functions in any calculation engine dialog in FileMaker. Keep in mind that just because you can do something does not mean it is actually useful.

There are several places that fit very well depending on the situation:

Calculation field
Auto-Enter Calculated value
Validation by calculation
Set Field Script/Button step
Insert Calculated Result Script/Button step
Show Custom Dialog
Set Variable Script/Button Step
Custom Functions
and more...

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Coding Considerations

Integrating the plug-in >