CSS Hyphens Not Working in Firefox?

问题

I am attempting to use CSS Hyphens. They work in IE 11 and Safari but does not work in Firefox properly and I am unsure why. Here is an example:

.container{
    width: 16.6667%;
    background:#ccc;
}
h3{
    font-size: 0.95rem;
    font-weight: 600;
    -moz-hyphens: auto;
    -webkit-hyphens: auto;
    -ms-hyphens: auto;
    hyphens: auto;
}

<div class="container">
<h3>DIAGNOSEVERFAHREN</h3>
</div>

When you run the snippet in Firefox the word DIAGNOSEVERFAHREN overflows the container and does not break. In Safari and IE it breaks like I expect. Why doesn't this work in Firefox?

Edit

As noted by Marat Tanalin's answer one must include the lang attribute for the hyphens to work correctly. I have this as my <html> tag:

<html class="no-js" lang="de">

回答1:

For some strange reason it seems to be because the word is in capital letters. I assume it has something to do with Firefox not thinking that it is a word when it searches the hyphenation dictionary.

I couldn't find any bug reports on it but @MaratTanalin thinks that it has been fixed in Firefox v38.

p {
    width: 55px;
    border: 1px solid black;
    -moz-hyphens: auto;
    hyphens: auto;
}

<div>
    <h4>English</h4>
    <p lang="en" class="auto">DIAGNOSEVERFAHREN</p>
    <p lang="en" class="auto">Diagnoseverfahren</p>
    <p lang="en" class="auto">diagnoseverfahren</p>
</div>
<div>
    <h4>German</h4>
    <p lang="de" class="auto">DIAGNOSEVERFAHREN</p>
    <p lang="de" class="auto">Diagnoseverfahren</p>
</div>

Edit: It affects all capitalized and uppercase words. Apparently this is by design in Firefox and it won't be fixed anytime soon. Only German language supports the feature of hyphenating capitalized (not uppercase) words. https://bugzilla.mozilla.org/show_bug.cgi?id=656879

回答2:

Make sure the element or some of its parents has an appropriate lang attribute. It is crucial for CSS hyphens to work.

In general, at least the HTML element should have the attribute:

<html lang="en">

For uppercasing characters, use CSS instead of hardcoded uppercased text in HTML:

.example {text-transform: uppercase; }

Uppercased german text is not hyphenated in Firefox 37 and older due to the bug 1105644 fixed in Firefox 38.

回答3:

I got this type of issue on ios safari , there are multiple hyphens on that page few of those were not working while remaining works . but i am not supposed to use text-transform:uppercase, so increased the font size to 1px and it worked for me.

回答4:

Inorder to demonstrate the concept of hyphenation, you need to give the lang attribute is set to en on the parent element.

来源：https://stackoverflow.com/questions/28976543/css-hyphens-not-working-in-firefox

标签

css

firefox

hyphenation

css-hyphens