line breaks in a textarea

问题

I know when saving a textarea you can use the nl2br() or str_replace to change the /n to br tags etc. However what im not sure about how to insert line breaks into a textarea. I cant seem to find much about putting the data back into a textarea with those line breaks.

For example I have a form where users can update fields. So the user may enter:

foo
bar
baz

When that is saved to the database it would be saved as:

foo<br />bar<br />baz<br />

Now when that user goes back to that form after a page refresh all the fields are automatically populated with their previous data by taking the data from the database.

However the textarea shows the br tags as text instead of adding in the line breaks. i also tried changing the br tags to /n hoping the textarea would interpret these as line breaks but no joy. As well as this I also tried escaping etc.

So my questions are can this be done? Or more importantly can it be done using HTML/PHP (im using smarty). If that isnt possible can it be done using javascript?

Examples would be appreciated.

thanks for reading

回答1:

Don't do nl2br when you save it to the database. Do nl2br when you're displaying the text in HTML. I can strongly recommend to not store any HTML formatting in the database (unless you're using a rich HTML editor as well, in which case it would be silly not to).

A newline \n will just become a newline in the textarea.

回答2:

You could use str_replace to replace the <br /> tags into end of line characters.

str_replace('<br />', PHP_EOL, $textarea);

Alternatively, you could save the data in the database without calling nl2br first. That way the line breaks would remain. When you display as HTML, call nl2br. An additional benefit of this approach is that it would require less storage space in your database as a line break is 1 character as opposed to "<br />" which is 6.

回答3:

Ahh, it is really simple

just add

white-space:pre-wrap;

to your displaying element css

I mean if you are showing result using <p> then your css should be

p{
   white-space:pre-wrap;
}

回答4:

You can use following code:

$course_description = nl2br($_POST["course_description"]);
$course_description = trim($course_description);

回答5:

Some wrong answers are posted here. instead of replacing \n to <br />, they are replacing <br /> to \n

So here is a good answer to store <br /> in your mysql when you entered in textarea:

str_replace("\n", '<br />',  $textarea);

回答6:

My recommendation is to save the data to database with Line breaks instead parsing it with nl2br. You should use nl2br in output not input.

For your question, you can use php or javascript:

PHP:

str_replace('<br />', "\n", $textarea);

jQuery:

$('#myTextArea').val($('#myTextArea').val().replace(@<br />@, "\N"));

回答7:

The simple way:

1. Use this to insert into mysql:

   $msg = $_GET['msgtextarea']; //or POST and my msg field format: text
   $msg = htmlspecialchars($msg, ENT_QUOTES);

2. And use this for output:

   echo nl2br($br['msg']);

回答8:

PHP Side: from Textarea string to PHP string

$newList = ereg_replace( "\n",'|', $_POST['theTextareaContents']);

PHP Side: PHP string back to TextArea string:

$list = str_replace('|', '
', $r['db_field_name']);

回答9:

This works on me.

 str_replace(array("\r", "\n"), '
', $textareavalue);

回答10:

From PHP using single quotes for the line break worked for me to support the line breaks when I pass that var to an HTML text area value attribute

PHP

foreach ($videoUrls as $key => $value) {
  $textAreaValue .= $value->video_url . '\n';
}

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

HTML/JS

$( document ).ready(function() {
    var text = "<?= htmlspecialchars($textAreaValue); ?>";
    document.getElementById("video_urls_textarea").value = text;
});

回答11:

What I found works in the form is str_replace('<br>', PHP_EOL, $textarea);

回答12:

I'm not sure this is possible but you should try <pre><textarea> ... </textarea></pre>

回答13:

<?php
$smarty = new Smarty;
$smarty->assign('test', "This is a \n Test");
$smarty->display('index.tpl');
?>

In index.tpl

{$test|nl2br}

In HTML

This is a<br />
test

来源：https://stackoverflow.com/questions/6480655/line-breaks-in-a-textarea