In my previous article, I was saying that you can even use a response dialog to modify variables, or control flow, at runtime. If you've got a function that you need to wring out thoroughly, set it up so that you can input values dynamically via a response dialog.
You can even enter code into the response dialog at runtime. Here's an example showing how:
x = 5;y = 8;str = app.response("Enter some code.");func = new
Function(str);app.alert( func() );
If you run this code and (when the dialog comes up) enter "return x * y", an alert will
appear with the value "40" displayed. If you had entered "return x/y", the alert would come
up with "0.625" showing.
What's happening is that the response dialog (the line of code beginning with str =,
above) is giving you a chance to type some JavaScript in ordinary ASCII. Whatever you type
is captured into a string, str. The trick is to get this string to execute now, while
your Form is up and running. It turns out we can do that, if we take the string stored in
str and submit it as the argument to the Function constructor.
Let's back up and talk about declaring functions in JavaScript. You're probably familiar
with the following way of declaring a function:
function myFunc( x, y) { (some code here) }
The keyword 'new'
This is fine for setting up a function whose content is known prior to runtime. Most of
the functions you'll write will be set up this way. But there is another way to declare a
function: namely, using the Function constructor. This implies using the new keyword.
The constructor takes, as an argument, a string containing whatever code statements you want
to put in the function. The constructor returns a Function object, as in:
theFunction = new Function(str)
Here, theFunction is our new Function object. To call it, we just use the
parentheses operator in the normal way:
theFunction();
If the function returns a value, then just capture the value in a variable as you
normally would.
Note carefully what we've been able to do. We've found a way to turn a string into
a function (using the Function constructor). Since strings can be captured at runtime
(via dialogs, form fields, and so on), this means we can actually create new
functions at runtime, from strings entered at runtime. We can actually insert new
code into already-running code, using a response dialog... and run the new code!
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.