ikiwiki/doc/todo/color_plugin.mdwn

216 lines
7.6 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

Recently I've wanted to colour some piece of text on my Ikiwiki page.
It seems that Markdown can do it only using HTML tags, so I used
`<span class="color">foo bar baz</span>`.
However, in my opinion mixing Markdown syntax and HTML tags is rather ugly,
so maybe we should create a new color plugin to add more color to Ikiwiki ;)
I know that another Wikis have similar plugin, for example
[WikiDot](http://www.wikidot.com/).
I've noticed that htmlscrubber plugin strips `style` attribute, because of
security, so probably we need to use `class` attribute of HTML. But then
we have to customize our `local.css` file to add all color we want to use.
It's not as easy in usage like color name or definition as plugin argument,
but I don't have a better idea right now.
What do you think about it? --[[Paweł|ptecza]]
> Making a plugin preserve style attributes can be done, it just has to add
> them after the sanitize step, which strips them. The general method is
> adding placeholders first, and replacing them with the real html later.
>
> The hard thing to me seems to be finding a syntax that is better than a
> `<span>`. A preprocessor directive is not really any less ugly than html
> tags, though at least it could play nicely with nested markdown: --[[Joey]]
>
> \[[!color red,green """
> Xmas-colored markdown here
> """]]
>> I'm glad you like that idea. In my opinion your syntax looks good.
>> Out of curiosity, why did you used 2 colors in your example? What is HTML
>> result for it? ;)
>>> I was thinking one would be foreground, the other background. Don't
>>> know if setting the background makes sense or not.
>> I can try to create that plugin, if you are too busy now. I'm not Perl
>> hacker, but I wrote a lot of Perl scripts in my life and color plugin
>> doesn't seem to be very hard task. --[[Paweł|ptecza]]
>> Yes, it's a good intro plugin, have at it! --[[Joey]]
---
This is a RC1 of my `color` plugin. It works for me well, but all your
comments are very welcome. --[[Paweł|ptecza]]
> Sure, I have a couple.
>> Great! Thank you very much! --[[Paweł|ptecza]]
> The preprocess function is passed named parameters. The hack you have of
> hardcoding use of `$_[0]` and `$_[2]` can fail at any time.
>> But the problem is that arguments of my plugin don't have a name.
>> How can I identify them in `params` hash?
>> Similar hardcoded method I've found in `img` plugin :) But only one
>> argument is not named there (image path).
>>> I think I hadn't realized what you were doing there. The order
>>> for unnamed parameters can in fact be relied on.
>>>
>>> --[[Joey]]
>> Maybe I shouldn't use so simple plugin syntax? For following syntax
>> I wouldn't have that problem:
>> \[[!color fg=white bg=red text="White text on red background"]]
> `replace_preserved_style` is passed a single parameter, so its prototype
> should be `($)`, not `(@)`. Ditt `preserve_style`, it should have
> `($$)`.
>> OK, it will be fixed.
> The sanitize hook is always passed `$params{content}`, so there should be
> no reason to check that it exists. Also, it shouldn't be done in a
> sanitize hook, since html sanitization could run _after_ that santize
> hook. It should use a format hook.
>> Probably you're right. It was rather paranoid checking ;) Thanks for
>> the hook hint!
> The preprocess hook needs to call `IkiWiki::preprocess` on the content
> passed into it if you want to support nesting other preprocessor
> directives inside the color directive. See `preprocess_toggleable` in the
> toggle plugin, for example.
>
> I'm not a big fan of the dummy text `COLORS { ... } SROLOC;TEXT { ... TXET }`
> The method used by toggle of using two real `<div>`s seems slightly
> better. --[[Joey]]
>> I don't like that too, but I didn't have better idea :) Thank you for
>> the hint! I'll take a look at `toggle` plugin.
---
And here is RC2 of that plugin. I've changed a plugin syntax, because the old
seems to be too enigmatic and it was hard to me to handle unnamed parameters
in not hardcoded way. I hope that my changes are acceptable for you.
Of course, I'm open for discussion or exchange of ideas :) --[[Paweł|ptecza]]
> One question, why the 2px padding for span.color? --[[Joey]]
--- /dev/null 2008-06-21 02:02:15.000000000 +0200
+++ color.pm 2008-07-27 14:58:12.000000000 +0200
@@ -0,0 +1,69 @@
+#!/usr/bin/perl
+# Ikiwiki text colouring plugin
+# Paweł Tęcza <ptecza@net.icm.edu.pl>
+package IkiWiki::Plugin::color;
+
+use warnings;
+use strict;
+use IkiWiki 2.00;
+
+sub import { #{{{
+ hook(type => "preprocess", id => "color", call => \&preprocess);
+ hook(type => "format", id => "color", call => \&format);
+} #}}}
+
+sub preserve_style($$$) { #{{{
+ my $foreground = shift;
+ my $background = shift;
+ my $text = shift;
+
+ $foreground = defined $foreground ? lc($foreground) : '';
+ $background = defined $background ? lc($background) : '';
+ $text = '' unless (defined $text);
+
+ # Validate colors. Only color name or color code are valid.
+ $foreground = '' unless ($foreground &&
+ ($foreground =~ /^[a-z]+$/ || $foreground =~ /^#[0-9a-f]{3,6}$/));
+ $background = '' unless ($background &&
+ ($background =~ /^[a-z]+$/ || $background =~ /^#[0-9a-f]{3,6}$/));
+
+ my $preserved = '';
+ $preserved .= '<span class="color">';
+ $preserved .= 'color: '.$foreground if ($foreground);
+ $preserved .= '; ' if ($foreground && $background);
+ $preserved .= 'background-color: '.$background if ($background);
+ $preserved .= '</span>';
+ $preserved .= '<span class="colorend">'.$text.'</span>';
+
+ return $preserved;
+
+} #}}}
+
+sub replace_preserved_style($) { #{{{
+ my $content = shift;
+
+ $content =~ s!<span class="color">((color: ([a-z]+|\#[0-9a-f]{3,6})?)?((; )?(background-color: ([a-z]+|\#[0-9a-f]{3,6})?)?)?)</span>!<span class="color" style="$1">!g;
+ $content =~ s!<span class="colorend">!!g;
+
+ return $content;
+} #}}}
+
+sub preprocess(@) { #{{{
+ my %params = @_;
+
+ # Preprocess the text to expand any preprocessor directives
+ # embedded inside it.
+ $params{text} = IkiWiki::preprocess($params{page}, $params{destpage},
+ IkiWiki::filter($params{page}, $params{destpage}, $params{text}));
+
+ return preserve_style($params{foreground}, $params{background}, $params{text});
+} #}}}
+
+sub format(@) { #{{{
+ my %params = @_;
+
+ $params{content} = replace_preserved_style($params{content});
+ return $params{content};
+} #}}}
+
+1
--- /dev/null 2008-06-21 02:02:15.000000000 +0200
+++ color.mdwn 2008-07-27 15:04:42.000000000 +0200
@@ -0,0 +1,25 @@
+\[[!template id=plugin name=color core=0 author="[[ptecza]]"]]
+
+This plugin can be used to color a piece of text on Ikiwiki page.
+It's possible setting foreground and/or background color of the text.
+
+You can use name (e.g. `white`) or HTML code of colors (e.g. `#ffffff`)
+to define colors.
+
+Below are a few examples:
+
+ \[[!color foreground=white background=#ff0000 text="White text on red background"]]
+
+Foreground color is defined as a word, background color is defined as HTML
+color code.
+
+ \[[!color foreground=white text="White text on default color background"]]
+
+Background color is missing, so the text is displayed on default background.
+
+ \[[!color background=#ff0000 text="Default color text on red background"]]
+
+Foreground is missing, so the text has default color.
+
+This plugin is not enabled by default. You can do that in [[ikiwiki.setup]]
+file (hint: `add_plugins` variable).
--- style.css-orig 2008-07-27 15:12:39.000000000 +0200
+++ style.css 2008-07-27 15:15:06.000000000 +0200
@@ -333,3 +333,7 @@
background: #eee;
color: black !important;
}
+
+span.color {
+ padding: 2px;
+}