Using FileMaker Pro Advanced > Using the Data Viewer (FileMaker Pro Advanced)
Using the Data Viewer (FileMaker Pro Advanced)
You can use the Data Viewer to monitor expressions like field values, local and global variables, and calculation formulas. You can monitor expressions while running scripts or while testing them in the Script Debugger. You can also monitor field values and variables in the database file.
The Current tab shows:
fields used by the currently running script whether they are referenced directly in the script or indirectly in calculations
local variables used by the currently running script
global variables independent of any script; global variables are displayed even if no scripts are currently running
The Watch tab monitors expressions. You can enter one expression per row in the Data Viewer. When you use the Data Viewer with the Script Debugger, the Watch tab displays expressions from paused scripts, letting you see how data changes as you step though a script.
To monitor fields and variables in the currently running script:
1. Choose Tools menu > Data Viewer, or click Open/Close data viewer button in the Script Debugger.
2. Click the Current tab.
To monitor expressions:
1. Click the Watch tab.
2. Click + or double-click an existing expression.
3. In the Edit Expression dialog box, enter an expression as in the Specify Calculation dialog box.
If your privileges don’t allow you to use the Data Viewer, click Lock button, then log in to an account that has full access privileges.
If you log in to edit restricted-access scripts in the Script Debugger, your access privileges also apply to the Data Viewer. If you log in from the Data Viewer, your access privileges also apply to the Script Debugger. In either case, your editing privileges last until you close the Script Debugger or the Data Viewer. See Debugging scripts (FileMaker Pro Advanced).
You can see global and local variables that are declared outside of scripts only if you have full access privileges to the file.
In the Edit Expression dialog box, Automatically evaluate updates the result as you type the expression. If an expression takes too long to evaluate automatically, deselect this option and click Evaluate to manually update the result.
In the Current tab:
If you double-click an expression, the Current Value dialog box opens to show the expression’s entire value, which you can copy. You can modify the values of variables, but not field values. Close the dialog box to commit the modified values.
Repeating fields are listed only if they contain values, like this: <fieldname>[<value>]. The first repetition is shown without brackets. If the repetitions are calculated, the values are not shown until the script step is reached in which the calculation is solved.
Related topics 
Working with formulas and functions
Defining calculation fields
Specify Calculation dialog box