Carriage returns in text areas

How to recognize carriage returns received from a text area

[Solta]

Hi, I'm new to PHP and have a quick question

I have a form in an html document where users submit short articles in a text area to editors of a news-based site. I know how to set up the form to create an html/php document with the information submitted, but how do I get the carriage returns in the text area to transfer to <p></p> or <br> tags in html. For example, when submitting these posts here, the carriage returns are recognized.

Another question. Do I have to do anything special to the text area which would allow users to include html tags for formatting?

thanks,
-Solta

[daisho]

but how do I get the carriage returns in the text area to transfer to <p></p> or <br>

$html_str=str_replace("\n","<br>",$_REQUEST['textarea_field']);

Do I have to do anything special to the text area which would allow users to include html tags for formatting?

No. You have to do something special to make sure they can't :)

daisho.

[grahamstewart]

Try this little lot...

// Use \n for newline on all systems
$html = preg_replace("/(\r\n¦\n¦\r)/", "\n", $html);
 
// Only allow two newlines in a row.
$html = preg_replace("/\n\n+/", "\n\n", $html);
 
// Put <p>..</p> around paragraphs
$html = preg_replace('/\n?(.+?)(\n\n¦\z)/s', "<p>$1</p>", $html);
 
// Convert newlines not preceded by </p> to a <br /> tag
$html = preg_replace('¦(?<!</p>)\s*\n¦', "<br />", $html);

This will surround blocks of text (i.e. text seperated by a blank line) with <p> tags and will add <br> for other line breaks.

P.S. Change the broken vertical bars for the one on your keyboard (the forum changes it y'see).

[Solta]

Thanks a lot to both of you. Wow, what a fast response.

-Solta

[andreasfriedrich]

Have a look at these old posts Parsing double newlines into <p> tags using PHP - How to run a full Perl-style regular expression in PHP? [webmasterworld.com] and Newby help with MySQL / CGI / HTML - Newlines missing when parsing database data [webmasterworld.com] as well.

Andreas

[lorax]

You could also use nl2br() [php.net]

>> nl2br --  Inserts HTML line breaks before all newlines in a string

[daisho]

very cool lorax. Never knew about that one. cleaner than a str_replace :)

daisho.

[grahamstewart]

Ahh but nl2br() doesn't insert any <p> tags, only <br>.
Whereas those 4 little preg_replaces above will convert..

A paragraph that has a
line break in it.

And another paragraph.

into

<p>A paragraph that has a <br>
line break in it.</p>
<p>And another paragraph.</p>

which is much nicer markup IMHO. :)

[lorax]

That's very true grahamstewart. I'd use it combination with some code to evaluate for paragraphs (\n\n).

[andreasfriedrich]

>>those 4 little preg_replaces above

But why use 4 when 1 will suffice? ;-)

[grahamstewart]

But why use 4 when 1 will suffice? ;-)

Readability? :p

Plus the four preg_replaces also deal with inserting <br> tags where required, which the single line solution does not.

[jatar_k]

andreas is right, if 1 will do then 4 is a monstrous waste of time and processing power. ;)

[grahamstewart]

True, using one massive preg_replace might be a good couple of millionths of a second faster than using four simple ones. As PHP will spend longer analysing the regular expression but will only have to scan the text once. ;)

seriously tho, this might actually be important if you are converting megs and megs of text into html at a time.

But I think for the usual application (e.g. handling of user entered text from forms) the four preg_replace solution is the way to go. :)

[snappca]

Finally! I've been searching the web looking for someone that has had a similar problem to my own...since it seems like everyone else is not having my probs, maybe I could get a helping hand.

I've been trying to piece together a simple note taking app using a text area as the input form. The problem that I'm having though is that I don't want the data stored with html tags...I want the person to be able to go back and edit the note whenever they want, without having to remove the tags.

It seemed to me that the only way I could get the line breaks to be recognized by PHP was to escape the string in javascript first and pass that up. Since javascript escapes EVERYTHING I was a bit flustered at what I was passing. Also...my app hangs if I try to submit to long a string, so now I'm really confused since I didn't think there'd be a limit to what I could pass. This thing also doesn't allow for special characters like & # @ $ and things like that.....I'm still a newbie with PHP so I'd be real thankful if I could get some help.

Thanks

-Chris

[willybfriendly]

snappca -

trim($string);// trims white space from the beginning/end of string
striptags($string);// strips all html tags
htmlspecialchars($string);// converts special characters to html entities
addslashes($string);// escapes single quotes, double quotes and backslash characters

WBF