Regular Expression to lower case

Im trying to make strings matched by a regular expression, convert to lower case

eg: <TABLE> to <table> and <B> to <b>

why doesnt the regexp below work?

$dic= preg_replace("/<([A-Z]*)>/",strtolower("$1"),$dic);

Thanks
THT

 

You need to tell preg_replace that the replacement string is PHP code not a string, so use the "e" modifier, and enclose the strtolower bit in quotes.

$dic= preg_replace("/<([A-Z]*)>/e","strtolower('$1')",$dic);

Code (markup):

cheers

John

 

cheers john,

just one last question:


How do i handle this:

<IMG
ALT="" SRC="http://cache.lexico.com/dictionary/graphics/AHD4/GIF/abreve.gif" height="15" width="7" ALIGN="BOTTOM">

Code (markup):

cos of the newline?

 

The newline is not a problem per se, its just treated like any other character, so the "ALT=..." etc will also cause problems. If you only want to lowercase the HTML tags, and not the attribute names also, you could use something like

$dic=  preg_replace("/<\/?([A-Z]+)[^>]*>/Ue", "strtolower('$1')",$dic);

Code (markup):

The "\/?" should cope with the closing tags too, and the U flag tells it not to be greedy - i.e. only get the first closing >

Haven't ahd chance to test it but I think it should be OK

 

thanks john

I know i said last question, but....

Ive added a line abve as i need diferent behaviour for a tag:

$dic= preg_replace("/<img(.*)>/ei","strtolower('<img'.\"$1\".' />')",$dic);

Code (markup):

should take

<img blah blah blah>

and make it

<img blah blah blah />

but it doesnt..... help?

 

Two possibilities that I can think of. Either the escaped and unescaped quotes are confusing it ( they confused me ), or it is the greediness again - matching the last > that it finds instead of the first.
try

$dic= preg_replace("/<img(.*)>/eiU","strtolower('<img$1' />')",$dic);

Code (markup):

 

John, you are wonderful!

one last one (honest this time!)

I wan to find image tags that dont have alt tags and add a blank alt tags (alt="")

Whats the best way to do this?

 

Don't know how to match negative patterns, but you could hack it by writing a function to check using strpos. Something along the lines of

function checkForAltTag ( $imageString ) {
if ( strpos( $imageString, "alt=" ) === false ) {
    return str_replace("<img", "<img alt=\"\"", $imageString);
} else {
    return $imageString;
}
} // end checkForAltTag

$dic= preg_replace("/(<img.*>)/eiU","checkForAltTag($1)",$dic);

Code (markup):

I'm sure that there's a more elegant way of doing this, but I can't think of it right now

hope it helps

John