PHP function to compact javascript code?

[Matt Kruse]

I am far from a PHP expert, and I've been struggling to create a function
which will take a javascript .js file and "compact" it as much as possible.
Meaning, remove all comments and unnecessary whitespace. "Obfuscatio n" is
not necessary. Obviously, the compacted javascript should run identically to
the original javascript.

Can anyone point me to an existing function that does this?

Thanks!

--
Matt Kruse
http://www.JavascriptToolbox.com
http://www.AjaxToolbox.com

[Colin McKinnon]

Matt Kruse wrote:

I am far from a PHP expert, and I've been struggling to create a function
which will take a javascript .js file and "compact" it as much as
possible. Meaning, remove all comments and unnecessary whitespace.
"Obfuscatio n" is not necessary. Obviously, the compacted javascript should
run identically to the original javascript.

Can anyone point me to an existing function that does this?

No, but if you're the Matt Kruse I'm thinking of, you know how to program in
Javascript. Given the similarity in syntax, you may find the PHP5 function
php_strip_white space() meets your requirements. If not (or if you're
running an earlier version) then...

Regular expressions can be used for all of this in PHP, although I'd
probably use str_replce for most of the whitespace stuff:

$js=str_replace ("\t", ' ', $js); // tab chars
$js=str_replace ("\r", '', $js); // strip CR
$js=str_replace ("\n\n", "\n", $js); // double NL
$js=str_replace (' ', ' ', $js); // double space -> single space

I'd also strip a space following an operator/bracket/quote but
that needs something smarter - hence regexes - these need a bit
more thought put into them. ISR the question about stripping comments
coming up in the PHP newsroups several times before - try Google.

HTH

C.

[JDS]

On Sun, 14 Aug 2005 13:52:01 -0500, Matt Kruse wrote:

Can anyone point me to an existing function that does this?

I can't. But a beter question is, why bother? Is your javascript stuff
really so huge that taking out the whitespace will matter that much?

--
JDS | je*****@go.away .com
| http://www.newtnotes.com
DJMBS | http://newtnotes.com/doctor-jeff-master-brainsurgeon/

[RobG]

Matt Kruse wrote:

I am far from a PHP expert, and I've been struggling to create a function
which will take a javascript .js file and "compact" it as much as possible.
Meaning, remove all comments and unnecessary whitespace. "Obfuscatio n" is
not necessary. Obviously, the compacted javascript should run identically to
the original javascript.

Can anyone point me to an existing function that does this?

Thanks!

<URL:http://www.crockford.c om/javascript/jsmin.html>
" JSMin is a filter which removes comments and unnecessary whitespace
from JavaScript files. It typically reduces filesize by half, resulting
in faster downloads. It also encourages a more expressive programming
style because it eliminates the download cost of clean, literate
self-documentation. "

Obfuscation is not performed, uglification is. ;-)


--
Rob

[Matt Kruse]

JDS wrote:

I can't. But a beter question is, why bother? Is your javascript
stuff really so huge that taking out the whitespace will matter that
much?

Whitespace reduction often isn't as dramatic as comment removal, but with
both combined - yes.

If comments are used liberally and documentation for a library is included
within the source file itself, a js file could be, say, 50k or more.

When compacted, the same file could be 25k or even less. Since it has the
same functionality, there's no reason _not_ to compact it and save some
bandwidth and download time.

--
Matt Kruse
http://www.JavascriptToolbox.com
http://www.AjaxToolbox.com

[Matt Kruse]

RobG wrote:

URL:http://www.crockford.com/javascript/jsmin.html

1) It ain't PHP. I want PHP :)

2) I've actually messed with jsmin before and found that it didn't handle
some code correctly. I forget the code that I tested it with, but it
included closures and some "shortcut" coding styles, and it made the
resulting code generate syntax errors.

3) Uglification is not desireable :)

--
Matt Kruse
http://www.JavascriptToolbox.com
http://www.AjaxToolbox.com

[Tim Roberts]

Colin McKinnon <co************ **********@ntlw orld.deletemeun lessURaBot.com>
wrote:

Matt Kruse wrote:

I am far from a PHP expert, and I've been struggling to create a function
which will take a javascript .js file and "compact" it as much as
possible. Meaning, remove all comments and unnecessary whitespace.
"Obfuscatio n" is not necessary. Obviously, the compacted javascript should
run identically to the original javascript.

Can anyone point me to an existing function that does this?

...
Regular expressions can be used for all of this in PHP, although I'd
probably use str_replce for most of the whitespace stuff:

$js=str_replac e("\t", ' ', $js); // tab chars
$js=str_replac e("\r", '', $js); // strip CR
$js=str_replac e("\n\n", "\n", $js); // double NL
$js=str_replac e(' ', ' ', $js); // double space -> single space

It isn't that easy. This won't strip // type comments, and it will screw
up all of the string constants. It isn't rocket science, but you basically
need to implement a miniature Javascript parser to make this work reliably.
--
- Tim Roberts, ti**@probo.com
Providenza & Boekelheide, Inc.

[ASM]

Matt Kruse wrote:

RobG wrote:

URL:http://www.crockford.com/javascript/jsmin.html

No version for Mac ? :-(
1) It ain't PHP. I want PHP :)

I do not know PHP but I heard something about gzip ...

if your server has the good library
and if you accept files *.php

<?php ob_start('ob_gz handler'); ?>
<!DOCTYPE HTML PUBLIC
blah blah and rest of page
</html>

would compress file on fly via gzip
(I've seen gain : up to 90% if no image)

You can aslo compress your files at home with gZip (*.gz)
and then upload them on your server

Every browser (even NC3)
can decompress this datas on fly in few mili-seconds


--
Stephane Moriaux et son [moins] vieux Mac

[Martin Bialasinski]

"Matt Kruse" <ne********@mat tkruse.com> wrote:

RobG wrote:

URL:http://www.crockford.com/javascript/jsmin.html

1) It ain't PHP. I want PHP :)

Convert it from C to PHP :-)

But if you can compile C on your server, I would not bother and just
use system() to call it.

http://jscompact.sourceforge.net/ is an alternative for jsmin that
uses spidermonkey. Using a real JS engine, it should be even
better.
Bye,
Martin

[Randy Webb]

Matt Kruse said the following on 8/14/2005 10:32 PM:

JDS wrote:

I can't. But a beter question is, why bother? Is your javascript
stuff really so huge that taking out the whitespace will matter that
much?

Whitespace reduction often isn't as dramatic as comment removal, but with
both combined - yes.

If comments are used liberally and documentation for a library is included
within the source file itself, a js file could be, say, 50k or more.

When compacted, the same file could be 25k or even less. Since it has the
same functionality, there's no reason _not_ to compact it and save some
bandwidth and download time.

Read the file in with PHP.
Split it on line boundaries (if it doesn't already) so that you end up
with an array that is the same length as the number of lines of code.

Loop through the array and remove any empty entries (blank lines in the
code), entries that start with \\.

Then you would have to write a loop that would find comments that start
with \* and find the next entry that ended in *\ and remove them.

Should remove all the comments (unless they are inline comments :) )

var k = "My mama"; //This var keeps track of my Mama

Sounds like fun to try to write it but it's been a while for PHP, might
give me a good reason to freshen up on it. If not, write it in JS and
let you convert it to PHP :)

--
Randy
comp.lang.javas cript FAQ - http://jibbering.com/faq & newsgroup weekly