Re: Regular Expressions

m_j_mather@yahoo.com.au (Mark) writes:


> I just can't seem to figure out how to invent a regular expression
> that will strip all HTML tags (except TABLE tags) out of a string
> and leave the rest of the text. When a TABLE tag is encountered i
> need to strip everything under it.


If your HTML happens to be well-formed XML, then you could do this
very easily with an XSLT [1] stylesheet:


    <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                                    version="1.0">
        <xsl:output method="text"/>
        <xsl:template select="table"/>
    </xsl:stylesheet>


The default behavior of XSLT is pretty much just to strip tags; here,
you're adding a template that says "when you find a table, do
nothing", including not recursing into children to print text.


> But how do I make it also strip entire TABLE elements?


Assuming you don't have nested tables, you could replace


    <((table>.*?</table)|(.{1-4})|(tabl[^e])|(table[^>]+))>


with the empty string (using Perl regexp syntax, so that .*? is a
"non-greedy" match-everything). If you could have tables within your
table cells, the problem is equivalent to the paren-matching problem
and a regexp isn't powerful enough.


    --dzm


[1] http://www.w3.org/TR/xslt

Return to the comp.compilers page.
Search the comp.compilers archives again.