How to restrict the Backslash(\) character

In ActionScript, if you want to restrict the characters that can be entered into a TextField (or TextInput), you use the restrict property. Check here for documentation.

For example, input_txt.restrict = "A-Z";
This restricts the characters to upperspace characters and disallows everything else.

And input_txt.restrict = "^0-9";
The ^ symbol indicates that whatever comes after that is disallowed. Here, the numbers 0 to 9 are not allowed, everything else is allowed.

The interesting part is what if you want to restrict the Backslash(\) character?

Apparently, the right way to do it is:
input_txt.restrict = "^\\\\";

Explanation?

From the livedocs documentation:
"You can use a backslash to enter a ^ or - verbatim. The accepted backslash sequences are \-, \^ or \\. The backslash must be an actual character in the string, so when specified in ActionScript, a double backslash must be used. "

So, the first two backslashes are as required, when you add the third backslash, the flex compiler thinks that you are trying to escape the " character. Hence you need the fourth backslash in the string.

Very interesting!

Shutterfly Gallery

I have been working on the flash part of Shutterfly Gallery for the past few months. It went public today. Hence thought I'd promote it on my blog. The pictures were taken during my Seattle trip during 2008 New Year's. Head over here to see this photobook in more detail and for more such beautiful photobooks.

Click here to view this photo book.