[thelist] javascript1.2 v mac regexp problem

[Andrew Clover]

Alex <alex at deltatraffic.co.uk> wrote:

>    var regexpress = new RegExp(/^[a-z]+$/i);

/^[a-z]+$/i is the literal syntax for RegExp objects; you don't need to 
pass one to the RegExp constructor, it's a RegExp already.

The RegExp constructor takes a string as parameter. If you pass in a 
RegExp instead there will be unspecified results; on Mac browsers it 
seems to convert the RegExp to the expected type String 
('/\/^[a-z]+$\//i', which when recompiled does not result in the pattern 
you want).

I personally prefer to construct RegExps from strings rather than using 
literal syntax, as it causes fewer syntax-error problems with eg. old 
Opera versions and some constructs between IE and Mozilla:

   var allLetters= new RegExp('^[a-z]+$', 'i');

(Also then you can dump the language="JavaScript1.2".)

> var testname=regexpress.test(forename);
> var testname2=regexpress.test(surname);

This name checker is rather unforgiving. Should someone be blessed with 
the names "Mary Jane O'Foo" or "Marie-Claude von Umläüt" they won't be 
able to use the form. A more liberal test like a simple 
is-not-blank-string or contains-at-least-one-letter might be less 
alienating.

 > var forename = document.FrmRegister.forename.value;

document.forms.FrmRegister.elements.forename.value for slightly more 
reliability.

-- 
Andrew Clover
mailto:and at doxdesk.com
http://www.doxdesk.com/