Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Change the guidelines about establishing base direction and mention ALM #136

Merged
merged 9 commits into from
Oct 17, 2024
Merged
Show file tree
Hide file tree
Changes from 3 commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Binary file added images/061C.png
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
12 changes: 6 additions & 6 deletions index.html
Original file line number Diff line number Diff line change
Expand Up @@ -875,13 +875,13 @@ <h4>Problems with control characters</h4>


<section id="rlmlrm">
<h4>RLM and LRM</h4>
<p>A word about the Unicode characters <span class="codepoint" translate="no"><img alt="RLM" src="images/200F.png"><code class="uname">U+200F RIGHT-TO-LEFT MARK</code></span> (RLM) and <span class="codepoint" translate="no"><img alt="LRM" src="images/200E.png"><code class="uname">U+200E LEFT-TO-RIGHT MARK</code></span> (LRM) is warranted at this point.</p>
<p>The first point to be clear about is that neither RLM nor LRM establish the base direction for a range of text.&nbsp; They are simply invisible characters with strong directional properties.</p>
<h4>Strong direction marks: RLM, LRM, and ALM</h4>
aphillips marked this conversation as resolved.
Show resolved Hide resolved
<p>A word about the Unicode characters <span class="codepoint" translate="no"><img alt="RLM" src="images/200F.png"><code class="uname">U+200F RIGHT-TO-LEFT MARK</code></span> (RLM), <span class="codepoint" translate="no"><img alt="LRM" src="images/200E.png"><code class="uname">U+200E LEFT-TO-RIGHT MARK</code></span> (LRM), and <span class="codepoint" translate="no"><img alt="ALM" src="images/061C.png"><code class="uname">U+061C ARABIC LETTER MARK</code></span> (ALM) is warranted at this point.</p>
<p>The first point to be clear about is that these three characters do not establish the base direction for a range of text.&nbsp; They are simply invisible characters with strong directional properties.</p>
aphillips marked this conversation as resolved.
Show resolved Hide resolved
<p>This means that you cannot use RLM for example, to make the text W3C appear to the left of the Hebrew text in the following example.</p>
<p>The title is "<span dir="rtl">פעילות הבינאום, W3C</span>".</p>
<p>For this you can only use metadata or the paired control characters.</p>
<p>Of course, if you are detecting base direction using first-strong heuristics then RLM and LRM can be useful for setting the base direction where the text in question begins with something that would otherwise give the wrong result, eg. </p>
<p>Of course, if you are detecting base direction using first-strong heuristics then RLM, ALM, and LRM can be useful for setting the base direction where the text in question begins with something that would otherwise give the wrong result, eg. </p>
<p>"<span dir="rtl">نشاط التدويل</span>" is how you say "i18n Activity" in Arabic.</p>
<p>Here an LRM could be placed at the start of the text, before the strong RTL Arabic characters, to prevent the algorithm from assuming that the text should be right-to-left. (Remember that if metadata is used to set the base direction, that character is ignored, unless the metadata specifically says that first-strong heuristics should be used.)</p>
</section>
Expand Down Expand Up @@ -964,7 +964,7 @@ <h4>Setting the default base direction</h4>
<h4>Establishing the base direction for paragraphs</h4>

<div class="req" id="bidi_block_change">
<p class="advisement">The content author must be able to indicate parts of the text where the base direction changes. At the block level, this should be achieved using attributes or metadata, and should not rely on Unicode control characters.</p>
<p class="advisement">The content author must be able to indicate parts of the text where the base direction changes. At the block level, this should be achieved using attributes or metadata, and should not require the content author to use Unicode control characters to control direction.</p>
</div>


Expand Down Expand Up @@ -1143,7 +1143,7 @@ <h3>Setting base direction for inline or substring text</h3>
</div>

<div class="req" id="bidi_inline_embed">
<p class="advisement">For markup, provide attributes that allow the user to (a) create an embedded base direction or (b) override the bidirectional algorithm altogether; the attribute should allow the user to set the direction to LTR or RTL or the aforementioned Auto in either of these two scenarios.</p>
<p class="advisement">For markup, provide attributes that allow the user to (a) create an isolated or embedded base direction or (b) override the bidirectional algorithm altogether. Such attributes should allow the user to set the direction to LTR, RTL, or Auto in either of these two scenarios.</p>
</div>
</section>

Expand Down