How can I use a multiline value for an HTML tag attribute? (i.e. how do I escape newline?)

Question

How do I include a newline in an HTML tag attribute?

For example:

<a href="somepage.html" onclick="javascript: foo('This is a multiline string.
This is the part after the newline.')">some link</a>

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Edit: Sorry, bad example, what if the tag happened to not be in javascript, say:

<sometag someattr="This is a multiline string.
This is the part after the newline." />

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Edit 2: Turns out the newline in the string wasn't my problem, it was the javascript function I was calling. FWIW, "
" can be used for newline in an HTML attribute.

Leucopenia

Answer 1

From what I remember about the HTML standard, character entities work in attributes, so this might work:

<sometag someattr="This is a multiline string.&#10;This is the part after the newline." />

I'm not sure if the "newline" you want ought to be 
 (\n) or 
 (\r\n), and I'm not sure if browsers will interpret it the way you want.

Why do you need it? What specific problem are you trying to solve by adding a newline in an HTML tag attribute?

Zhao

The XML standard for attribute normalization is: w3.org/TR/REC-xml/#AVNormalize You have a good memory :-) – Roslynrosmarin

It's not working in my case. Why? <input type="text" name="email" value="Enter email here" title="First line sentence.&#10;Second line sentence.><br /> – Shaeffer

@Baowen: you forgot to terminate your title attribute with a ". – Zhao

@MariusGedminas Hi thanks, that too. But even after adding the ", it's still not working. I am trying to display those texts in a tooltip via jQuery tooltip function. – Shaeffer

@Shaeffer newline in attributes aren't the same as newlines in the tool tip. A literally newline in HTML doesn't render as a newline – Pinfish

Great to find this here (and not at first there w3.org/TR/REC-xml/#AVNormalize). This is an important feature for MediaWiki extensions which often pipe arguments through attributes, for example <youtube description"first paragraph&#10;second paragraph">... – Shaunna

Answer 2

To include a multiline value, just continue the text of the html attribute on the next line in your editor e.g.

<input type="submit" value="hallo
hallo"> 

will put the second hallo under the first

Tantra

hmm... you're right. the specific problem i was encountering was with the newline inside the javascript, but i assumed it extended to any html attribute in general but i guess i was mistaken. :-/ – Leucopenia

What if there are some blank lines in the value? like <iframe srcdoc='....'>. I need put the whole html in the value string, I have to remove all the blank lines of it ? – Distance

Answer 3

As a general rule newlines in attributes are preserved so your second example would work fine. Did you try it? Can you give a specific example where you are having problems with it?

As test take a look at this:-

<a href="somepage3.html" onclick="javascript: alert(this.getAttribute('thing'))" thing="This is a multiline string.
This is the part after the newline.">some link</a>

The alert include the newline in the attribute.

Burnout

oops, turns out the problem was actually the javascript function i was calling, not the newline in the tag. – Leucopenia

Just to clarify, newlines in attribute values ARE preserved, – Phillis

Answer 4

<a href="somepage.html" onclick="javascript: foo('This is a multiline string. \
This is the part after the newline.')">some link</a>

Javascript needs a backslash at the end of the new line in a string.

Sprint

Answer 5

i'm not certain, but you can try \r or \n

javascript: foo('This is a multiline string.\rThis is the part after the newline.')

or

javascript: foo('This is a multiline string.\nThis is the part after the newline.')

Gottuard

What if it happened to not be within javascript? – Leucopenia

are my examples not what you're looking for? – Gottuard

Answer 6

Usually, line breaks in HTML source code display what you intended in the result.

(Depends on the editor of course)

Moia

Answer 7

Since it's in Javascript, you would use "\n" if inside double-quotes (not positive about single-quotes, I've been in PHP a lot lately.

Honestly, it's worth mentioning that you should use Events and a delegator instead of placing a javascript event directly on the element.

Orientate