CODEWITHSUNDEEP
htmlweb-standards
rajakvk
rajakvk

Reputation: 10123

What is practical purpose for bidirectional override "bdo"?

Before coming here, I tried myself by googling. After I read these two links

http://www.w3schools.com/tags/tag_bdo.asp

http://www.w3schools.com/tags/tryit.asp?filename=tryhtml_bdo

I still don't understand clearly what is the practical purpose?

Thanks in advance for those who shed some light on this.

Upvotes: 0

Views: 3970

Answers (3)

Noam Ashbell
Noam Ashbell

Reputation: 219

Try this:

<!DOCTYPE html><html><body><p dir="rtl"><bdo>This is a right to left English text</bdo></p><p dir="ltr"><bdo>זהו טקסט עברי משמאל לימין</bdo></p></body></html>

Upvotes: 0

Davi Herold
Davi Herold

Reputation: 1

I tried the code bellow, and noticed that it is apparently obsolete for Hebrew, at least:

<!DOCTYPE html>
<html>
<body>

<p>If your browser supports bi-directional override (bdo), the next line will be written from right to left (rtl):</p>

<p>חדשות, ידיעות מהארץ והעולם - עיתון הארץ</p>
<bdo dir="rtl">חדשות, ידיעות מהארץ והעולם - עיתון הארץ</bdo>

</body>
</html>

Both seemed to output the same line, which confused me, but prompted a search that lead me to the following article:

The bidirectional ordering of text in AbiWord is done automatically, closely following the Unicode Bidirectional Algorithm (UBA; see the Unicode Consortium website). The Unicode character set assigns each character certain directional properties which are then used by the UBA to order text. Thus, Hebrew or Arabic characters will automatically be treated as right-to-left, and English characters as left-to-right. There are some characters that are directionally ambiguous, and how they are treated by the UBA depends on what characters are found in their vicinity (this includes all white space and punctuation characters).

http://fantasai.tripod.com/qref/HTML4/structure/bdo.html

Hope it helps

Upvotes: 0

Trevor Tippins
Trevor Tippins

Reputation: 2847

Pretty striaghtforward. If you're writing a web page using a default language, such as English, that is rendered left-to-right, and you want to include a island of text in another language, such as a quote in Hebrew, that is rendered right-to-left you can use this tag to override the base direction in which the text is written onto the page in case the bi-directional algorithm is getting it wrong. You need to make sure that the font you're using supports the appropriate character set too, of course.

http://www.w3.org/TR/html40/struct/dirlang.html

Upvotes: 2

Related Questions