Spanning Lines & Dynamic Pattern Matching

[Jamie Jackson]

Two fairly basic questions:

I need to supply a method with an array of strings, which will
eventually be used to pattern match against another array of strings.

1. Is there a good way to span multiple lines when creating an array
from a list of strings? (I want the most readable list I can get.)

// The following doesn't seem to work
urlExclusions = newArray(
"my.domain. com/dir1",
"another.domain .com/dir2",
"third.domain.c om/blah"
);

2. When I'm looping over the above array in a method, what's the best
way to use these as patterns to match? Does "new
RegExp(urlExclu sions[i], "i") do all the necessary escaping of
whatever literals might be in the urlExclusions[i] string? (All
characters in the above strings should be treated as a literals. I
don't intend for that list to be a place to put RegEx.)

Example: I want to do something like this with the list:

for (var i=0; i < urlExclusions.l ength; i++) {
pattern = new RegExp(urlExclu sions[i], 'i');
if (pattern.test(' http://my.domain.com/dir1')) {
document.write( "Matched");
} else {
document.write( "Didn't Match);
}
}

Any tips are appreciated... I'm a newbie.

Thanks,
Jamie

[Jamie Jackson]

Re: Spanning Lines &amp; Dynamic Pattern Matching

On Mon, 25 Oct 2004 12:23:19 -0400, Jamie Jackson
<mcsqueebagePle aseDontSpamMe@h otmail.com> wrote:
[color=blue]
>// The following doesn't seem to work
>urlExclusion s = newArray(
> "my.domain. com/dir1",
> "another.domain .com/dir2",
> "third.domain.c om/blah"
>);[/color]

Oops... Yes, the "newArray" typo existed in my code. I separated those
words, and the multi-line now syntax works.

Question #2 is still valid, though.

Thanks,
Jamie

[Grant Wagner]

Re: Spanning Lines &amp; Dynamic Pattern Matching

Jamie Jackson wrote:
[color=blue]
> 2. When I'm looping over the above array in a method, what's the best
> way to use these as patterns to match? Does "new
> RegExp(urlExclu sions[i], "i") do all the necessary escaping of
> whatever literals might be in the urlExclusions[i] string?[/color]

No. The first parameter of new RegExp() is a string, that string must
have any characters that have special meaning escaped.
[color=blue]
> (All
> characters in the above strings should be treated as a literals. I
> don't intend for that list to be a place to put RegEx.)
>
> Example: I want to do something like this with the list:
>
> for (var i=0; i < urlExclusions.l ength; i++) {
> pattern = new RegExp(urlExclu sions[i], 'i');
> if (pattern.test(' http://my.domain.com/dir1')) {
> document.write( "Matched");
> } else {
> document.write( "Didn't Match);
> }
> }
>
> Any tips are appreciated... I'm a newbie.[/color]

You're going to have to identify any characters that have special meaning
to regex and escape them before you can use the text in urlExclusions[i].
You can either do this manually when you populate urlExclusions (assuming
the patterns are in a static array defined by you) or do it at run-time
(if the patterns are retrieved from an untrusted source during script
execution).

--
Grant Wagner <gwagner@agrico reunited.com>
comp.lang.javas cript FAQ - http://jibbering.com/faq

[Jamie Jackson]

Re: Spanning Lines &amp; Dynamic Pattern Matching

On Mon, 25 Oct 2004 21:08:26 GMT, Grant Wagner
<gwagner@agrico reunited.com> wrote:
[color=blue]
>Jamie Jackson wrote:
>[color=green]
>> 2. When I'm looping over the above array in a method, what's the best
>> way to use these as patterns to match? Does "new
>> RegExp(urlExclu sions[i], "i") do all the necessary escaping of
>> whatever literals might be in the urlExclusions[i] string?[/color][/color]

<snip>
[color=blue]
>You're going to have to identify any characters that have special meaning
>to regex and escape them before you can use the text in urlExclusions[i].
>You can either do this manually when you populate urlExclusions (assuming
>the patterns are in a static array defined by you) or do it at run-time
>(if the patterns are retrieved from an untrusted source during script
>execution).[/color]

The "untrusted" source is the next developer to add something to the
exclusion list. ;-)

1. Is there anything built-in to escape special characters, or does
one have to roll his own?
2. Is there some other flavor of substring matching in JS that is
case-insensitive, but otherwise vanilla?

Thanks for the feedback,
Jamie

[Jc]

Re: Spanning Lines &amp; Dynamic Pattern Matching

2. Sure:

var bFound = (sText.toUpperC ase().indexOf(s ToLookFor.toUpp erCase()) !=
-1);

[Jamie Jackson]

Re: Spanning Lines &amp; Dynamic Pattern Matching

On 25 Oct 2004 20:23:04 -0700, "Jc" <google@weinric hs.com> wrote:
[color=blue]
>2. Sure:
>
>var bFound = (sText.toUpperC ase().indexOf(s ToLookFor.toUpp erCase()) !=
>-1);[/color]

Oh yeah, that'll do it. :)

Thanks,
Jamie