4D v16.3Custom Watch Pane |
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4D v16.3
Custom Watch Pane
Custom Watch Pane
Directly below the Call Chain Pane is the Custom Watch Pane. This pane is used to evaluate expressions. Any type of expression can be evaluated, including fields, variables, pointers, calculations, built-in functions, your own functions, and anything else that returns a value. You can evaluate any expression that can be shown in text form. This does not cover picture and BLOB fields or variables. On the other hand, the Debugger uses deployed hierarchical lists to let you display arrays and pointers. To display BLOB contents, you can use BLOB commands, such as BLOB to text. In the following example, you can see several of these items: two variables, a field pointer variable and the result of a built-in function, and a calculation. You can add an expression to be evaluated in the Custom Watch Pane in the following way:
To create a blank expression, double-click somewhere in the empty space of the Custom Watch pane. This adds an expression ` New expression and then goes into editing mode so you can edit it. You can enter any 4D formula that returns a result. After you have entered the formula, type Enter or Return (or click somewhere else in the pane) to evaluate the expression. To change the expression, click on it to select it, then click again (or press Enter — numeric key pad) to go into editing mode. If you no longer need an expression, click on it to select it, then press Backspace or Delete. Warning: Be careful when you evaluate a 4D expression modifying the value of one of the System Variables (for instance, the OK variable) because the execution of the rest of the method may be altered. To help you enter and edit an expression, the Custom Watch Pane’s context menu gives you access the 4D formula editor. In fact, the context menu also proposes additional options. To display this menu, click anywhere in the Custom Watch pane using the right mouse button
For more information about the Formula Editor, see the 4D Design Reference manual.
See also
Call Chain Pane
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PROPERTIES
Product: 4D
HISTORY
ARTICLE USAGE
4D Language Reference ( 4D v16) |