SImple regex not working?

[cmschofield]

I have a simple regular expression that validates a middle name:
<cfset valid = REFind("^[A-Za-z' ]*$",FORM.middlename)>

I want the middle name to be optional, but when I try a blank entry in the form, the REFind returns 0. I though the star (*) would solve the problem but I can't seem to get it to work.

Any help would be greatly appreciated.

[Kronin555]

Read the quickdocs (especially the first comment).

http://livedocs.macromedia.com/coldfusion/6.1/htmldocs/functa63.htm#wp1111015

Basically, if you do an REFind("^$",FORM.middlename) it will return 0 whether or not the string is blank.

[cmschofield]

Theoretically, I've made the expression optional by adding the (*) for zero or many occurances of the character set [A-Za-z' ]. Have I got this wrong?

[Newsgroup_User]

On Wed, 27 Sep 2006 15:45:09 +0000 (UTC), cmschofield wrote:

> I have a simple regular expression that validates a middle name:
> <cfset valid = REFind("^[A-Za-z' ]*$",FORM.middlename)>
>
> I want the middle name to be optional, but when I try a blank entry in the
> form, the REFind returns 0.

Right. REFind() returns the character position at which the match starts,
right? So which character position would the match start at in a
zero-length string?

The problem here is there's no way of distinguishing between "no match" and
"match at position zero".

--
Adam

[Newsgroup_User · Accepted solution]

Java is a bit more clever than CF. See this example:

<cfset s = "">
<cfset sRegex = "^[A-Za-z']*$">

<cfset i = reFind(sRegex, s)>
<cfoutput>#i#</cfoutput><br />

<cfset b = s.matches(sRegex)>
<cfoutput>#b#</cfoutput><br />

--
Adam

[cmschofield]

Thanks Adam. I'll just use the Java method. The more I learn about the CF regular expression methods, the more I hate them.

Thank you.

[Newsgroup_User]

> Thanks Adam. I'll just use the Java method. The more I learn about the CF regular expression methods, the more I hate them.

I think they're fine (and much better in CFMX than in older versions).
REFIND() does exactly what it claims it does, and indeed was giving you the
correct answer, remember ;-)

CF and Java obviously use the same regex processor, so they have the same
shortcomings as far as what regex "grammar" they understand. For example
Perl's regexes do a whole bunch of stuff that neither Java nor CF can do,
and I presume PHP is the same.

I guess there are probably third-party Java classes out there that cover
more options, having said that (I've never had need to investigate yet).


I'd probably approach your situation in two steps:

<cfif not len(x) or reFind(regex,s)>

It's clearer in intend, for one thing.

--
Adam