Dynamic "match" / regex?

[Good Man]

Hi there

Ideally, I'd like to create one javascript function and pass the file
extension i'm looking for to see if its there:

<input type="file" onchange="check File('pdf',this )" />

and then have the function something like (w/ Prototype)


function checkFile(theEx tension,theFiel d) {
var field = $(theField);
var fieldName = field.name;
var fieldID = field.id;
var fieldValue = field.value;
var matchPattern = "/\."+theExtensio n+"$/im";
if (fieldValue.mat ch(matchPattern )) {
alert('Its a '+theExtension+ '!');
} else {
alert('no!');
}
}


The problem is, the line with "fieldValue.mat ch" is not using the "var
matchPattern" value (my RegEx expression)...

Can anyone make this work / must i use 'eval' to get the match to work
against the dynamic var I created?

[Good Man]

Re: Dynamic &quot;match&quo t; / regex?

Good Man <heyho@letsgo.c omwrote in news:Xns9962A25 2BF8F8sonicyout h@
216.196.97.131:

Hi there
>
Ideally, I'd like to create one javascript function and pass the file
extension i'm looking for to see if its there:
>
<input type="file" onchange="check File('pdf',this )" />

yes, the form field is properly made in real life:

<input type="file" id="myFile" name="myFile" onchange="check File
('pdf',this)" />

[RobG]

Re: Dynamic &quot;match&quo t; / regex?

On Jul 4, 5:56 am, Good Man <h...@letsgo.co mwrote:

Hi there
>
Ideally, I'd like to create one javascript function and pass the file
extension i'm looking for to see if its there:
>
<input type="file" onchange="check File('pdf',this )" />
>
and then have the function something like (w/ Prototype)
>
function checkFile(theEx tension,theFiel d) {
var field = $(theField);
var fieldName = field.name;
var fieldID = field.id;
var fieldValue = field.value;
var matchPattern = "/\."+theExtensio n+"$/im";

Try:

var matchPattern = new RegExp('\\.' + theExtension + '$','im');

When constructing a regular expression this way you must quote
backslashes, hence \\, so \b becomes \\b, \n becomes \\n, etc.

if (fieldValue.mat ch(matchPattern )) {

If all you are doing is matching the RegExp, use test:

if (matchPattern.t est(fieldValue) ) {


--
Rob

[Good Man]

Re: Dynamic &quot;match&quo t; / regex?

RobG <rgqld@iinet.ne t.auwrote in news:1183495647 .365626.100600
@j4g2000prf.goo glegroups.com:

> var matchPattern = "/\."+theExtensio n+"$/im";

>
Try:
>
var matchPattern = new RegExp('\\.' + theExtension + '$','im');
>
When constructing a regular expression this way you must quote
backslashes, hence \\, so \b becomes \\b, \n becomes \\n, etc.
>

> if (fieldValue.mat ch(matchPattern )) {

>
If all you are doing is matching the RegExp, use test:
>
if (matchPattern.t est(fieldValue) ) {

Many thanks RobG...