p:fileUpload allowTypes regex

Question

with this regex /(.|/)(xml|xml.p7m)$/ accept xxxxx.xml, xxxx.xml.p7m but don't understand why accept xxxxx.xsl

            <p:fileUpload id="invoiceFileUploadId" widgetVar="invoiceFileUpload" fileUploadListener="#{menuController.uploadInvoice}" multiple="true"
            allowTypes="/(\.|\/)(xml|xml\.p7m)$/" label="#{label['upload']}" auto="true" dragDropSupport="true" process="@this" update="@this"
            invalidFileMessage="#{label['msg.fileNotValid']}" onstart="blockUI();" oncomplete="onCompleteUpload();"/>

Answer 1

Maybe the question is a bit old, but since in Primefaces 6.1 the issue still exists, I just investigated that a bit.

You use the following value for allowTypes:

/(\.|\/)(xml|xml\.p7m)$/

I digged into the Primefaces JavaScript code to find the location where the type is actually checked, and found the following (formatted for better readability):

if (this.cfg.allowTypes 
    && !(
        this.cfg.allowTypes.test(a.type) 
        || this.cfg.allowTypes.test(a.name))) { 
    /* type not allowed */ 
}

Hint: a is a File, having the properties name containing the file name and - more interesting - type containing the MIME type of the file (e.g. 'application/pdf').

The above PF code snippet shows that a file is only rejected, if neither its name nor its MIME type match the RegExp specified in allowTypes.

For XSL-files, the MIME-type can very well be text/xml, which matches the RegExp. The regular expression is interpreted in two totally different semantic contexts.

Side note: I always wondered why Primefaces documentation have the (\.|\/) part in the regular expression. My findings give me the impression that the . is for file extension matching, and the / is for MIME type matching. Who am I to judge?

Update

As @kukeltje states in the comments: A regular expression like e.g. /\.(xml|xml\.p7m)$/ would fix the problem. Or let's say "avoid the problem", as the real cause of the problem is that the regular expression is interpreted in two totally different contexts.