all repos — h3rald @ 19f3724b35edc7f6b5e2f1a91e2062c8531cc51d

The sources of https://h3rald.com

content/glyph/book/extending/macro_def.html

 1
 2
 3
 4
 5
 6
 7
 8
 9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
<!DOCTYPE html>
<html lang="en">
	<head>
    <title>Defining Custom Macros - H3RALD</title>
		<link href='https://fonts.googleapis.com/css?family=Crimson+Text:400,400italic,600,600italic,700,700italic' rel='stylesheet' type='text/css'>
		
		
		
		<meta charset="utf-8" />
		<meta name="author" content="Fabio Cevasco" />
		<meta name="robots" content="all, follow" />
		<meta name="Revisit-After" content="2 Days" />
		<meta name="description" content="H3RALD - Fabio Cevasco's Web Site" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
		
		<meta name="keywords" content="h3rald, fabio cevasco, glyph, ruby" />
		<link rel="shortcut icon" href="/favicon.png" type="image/png" /> 
		<meta content="44.388041;9.073248" name="ICBM" />

		<link rel="stylesheet" type="text/css" href="/styles/bootstrap.css" />
		<link rel="stylesheet" type="text/css" href="/styles/github.css" />
		<link rel="stylesheet" type="text/css" href="/styles/style.css" />
    <!--[if lt IE 9]>
    <script src="https://html5shiv.googlecode.com/svn/trunk/html5.js"></script>
    <![endif]-->
    <script src="https://www.google.com/jsapi?key=ABQIAAAAr6RY1Z6dchG_sX9WDLSy3xRlq2n1sm52B5HDRR5tm6o8XM18FhR56xHNNH6CsX86uN5VoTrglpyOyQ" type="text/javascript"></script>
    <script src="/js/sevenup.js" type="text/javascript"></script>
    <script src="/js/sevenup_black.js" type="text/javascript"></script>
    <script src="https://code.jquery.com/jquery-latest.js" type="text/javascript"></script>
    <script src="/js/jquery-timeago.js" type="text/javascript"></script>
    <script src="/js/date.js" type="text/javascript"></script>
    <script src="/js/hyphenator.js" type="text/javascript"></script>
    <script src="/js/init.js" type="text/javascript"></script>
    <script src="/js/search.js" type="text/javascript"></script>
    <script src="/js/highlight.js" type="text/javascript"></script>
		<script src="/js/bootstrap.js" type="text/javascript"></script>
	</head>
	<body>
			
				<div class="container">
  <div class="row" id="header-row">
    <div class="col-md-6 main-title">
      <h1>
        
        <a href="/"><img src="/img/h3rald.png" alt="H3RALD" /></a>
      
      </h1>
    </div>
    <div class="col-md-4 col-md-offset-2">
      <div class="gcse-searchbox" data-enableAutoComplete="true"></div>
    </div>
  </div>
  <div id="search_results">
    <div class="gcse-searchresults" data-linkTarget="_top"></div>
  </div> 
  <div id="main-navbar" class="navbar navbar-inverse" role="navigation">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
    </div>
    <div class="navbar-collapse collapse">
      <ul class="nav navbar-nav">
        <li><a href="/"><i class="fa fa-home"></i> HOME</a></li>
        <li><a href="/projects/"><i class="fa fa-briefcase"></i> PROJECTS</a></li>
        <li><a href="/tags/"><i class="fa fa-tags"></i> TAGS</a></li>
        <li><a href="/archives/"><i class="fa fa-archive"></i> ARCHIVES</a></li>
        <li><a href="/about/"><i class="fa fa-question-circle"></i> ABOUT</a></li>
        <li><a href="/contact/"><i class="fa fa-envelope"></i> CONTACT</a></li>
      </ul>
    </div>
  </div>
</div>
        <div class="container">
				<article class="page">
			  <header class="row">
        <hgroup class="col-md-9">
      <h1>Defining Custom Macros</h1>
      <h2>Glyph</h2>
      </hgroup>
      </header>
      <section id="body-text" class="hyphenate">

							<nav class="navigation"><a href="/glyph/book/extending/internals.html">← A quick look at Glyph's internals</a> | <a href="/glyph/book/index.html">Contents</a> | <a href="/glyph/book/extending/params_attrs.html">Parameters and Attributes →</a></nav>
							  <p>Glyph was created wih extensibility in mind. You can freely extend Glyph Language by creating or overriding macros, to do whatever you like. Macro definitions are written in pure Ruby code and placed in <code>.rb</code> files within the <code>lib/macros/</code> folder of your project.</p>
<aside class="box">
<div class="box-title">Alternative Ways to Define Macros</div>
<p>You can also define macros:</p>
<ul>
	<li>inside your document, using the <a href="/glyph/book/macros/macros_core.html#m_macro_"><code>macro:</code></a> macro.</li>
	<li>Using the <a href="/glyph/book/macros/macros_core.html#m_include"><code>include</code></a> macro specifying the path to an <code>.rb</code> file containing macro definitions stored in the <code>lib/</code> directory (useful especially when <a href="/glyph/book/compiling/lite_mode.html#lite_mode">compiling single Glyph files</a>).</li>
</ul>
</aside>
<p>This is the source code of a fairly simple macro used to format a note:</p>
  <div class="CodeRay">
  <div class="code"><pre><span class="line-numbers"><a href="#n1" name="n1">1</a></span>macro <span class="symbol">:note</span> <span class="keyword">do</span>
<span class="line-numbers"><a href="#n2" name="n2">2</a></span>  <span class="string"><span class="delimiter">%{</span><span class="content">&lt;div class=&quot;</span><span class="inline"><span class="inline-delimiter">#{</span><span class="instance-variable">@name</span><span class="inline-delimiter">}</span></span><span class="content">&quot;&gt;&lt;span class=&quot;note-title&quot;&gt;</span><span class="inline"><span class="inline-delimiter">#{</span><span class="instance-variable">@name</span>.to_s.capitalize<span class="inline-delimiter">}</span></span><span class="content">&lt;/span&gt;</span></span>
<span class="line-numbers"><a href="#n3" name="n3">3</a></span><span class="string"><span class="content">    </span><span class="inline"><span class="inline-delimiter">#{</span><span class="instance-variable">@value</span><span class="inline-delimiter">}</span></span><span class="content"></span></span>
<span class="line-numbers"><a href="#n4" name="n4">4</a></span><span class="string"><span class="content"></span></span>
<span class="line-numbers"><a href="#n5" name="n5">5</a></span><span class="string"><span class="content">    &lt;/div&gt;</span><span class="delimiter">}</span></span>
<span class="line-numbers"><a href="#n6" name="n6">6</a></span><span class="keyword">end</span></pre></div>
</div>

  <p>The <code>macro</code> method takes a single <code>Symbol</code> or <code>String</code> parameter, corresponding to the name of the macro. In this case, the entire block (or <em>body</em> of the macro) is a <code>String</code> corresponding to what we want the macro to evaluate to: a <code>&lt;div&gt;</code> tag containing a note.</p>
<p>The body of the macro is evaluated in the context of the <a href="http://rubydoc.info/gems/glyph/Glyph/Macro"><code>Glyph::Macro</code></a> class, therefore its instance variables (like <code>@name</code> or <code>@value</code>) can be used directly.</p>
<aside class="box">
<div class="box-title">Why using <code>@name</code> instead of just &#8220;note&#8221;?</div>
<p>For the <code>note</code> macro, it absolutely makes no difference. However, by using <code>@name</code> it is possible to re-use the same code for the <code>tip</code>, <code>important</code> and <code>caution</code> macros as well, which are in fact only aliases of the <code>note</code> macro.</p>
</aside>
<p>The following table lists all the instance variables that can be used inside macros:</p>
  <table>
    <tr>
      <th>Variable</th>
      <th>Description</th>
    </tr>
    <tr>
      <td>
<code>@node</code>
</td>
      <td>
        <p>A <a href="http://rubydoc.info/gems/glyph/Glyph/MacroNode"><code>Glyph::MacroNode</code></a> containing information about the macro. Useful for accessing parent and child macros, and the current <a href="http://rubydoc.info/gems/glyph/Glyph/Document"><code>Glyph::Document</code></a>. Normally, instances of the <code>MacroNode</code> class contain the following keys:</p>
<ul>
	<li><code>:name</code>, the name of the macro.</li>
	<li><code>:source</code>, a <code>String</code> identifying the source of the macro (a file, a snippet, etc.)</li>
	<li><code>:value</code>, the value of the macro (populated after the document has been parsed and analyzed).</li>
	<li><code>:escape</code>, whether the macro is a <a href="/glyph/book/text_editing/esc_quot.html#esc_quot">quoting macro</a> or not.</li>
	<li><code>:document</code>, the instance of <code>Document</code> the macro is contained in (populated after the document has been parsed and analyzed).</li>
</ul>
<p>Note that the first two keys can also be accessed via instance variables.</p>
      </td>
    </tr>
    <tr>
      <td>
<code>@name</code>
</td>
      <td>The name of the macro.</td>
    </tr>
    <tr>
      <td>
<code>@source_name</code>
</td>
      <td>A <code>String</code> identifying the source of the macro (a file, a snippet, etc.).</td>
    </tr>
    <tr>
      <td>
<code>@source_topic</code>
</td>
      <td>A <code>String</code> identifying the source topic of the macro.</td>
    </tr>
    <tr>
      <td>
<code>@source_file</code>
</td>
      <td>A <code>String</code> identifying the source file of the macro.</td>
    </tr>
  </table>
  <section class="section">
<header><h1 id="h_85" class="toc">Representations</h1></header>
<p>There&#8217;s a small problem with the code used to define the <code>note</code> macro in the previous section: what if I want to format notes using HTML5 instead of <span class="caps">HTML</span>, or another output format?</p>
<p>Glyph supports different output formats, therefore macros must be format-independent! In fact, this is the actual source of the <code>note</code> macro:</p>
    <div class="CodeRay">
  <div class="code"><pre><span class="line-numbers"><a href="#n1" name="n1">1</a></span>macro <span class="symbol">:note</span> <span class="keyword">do</span>
<span class="line-numbers"><a href="#n2" name="n2">2</a></span>  <span class="instance-variable">@data</span>[<span class="symbol">:name</span>] = <span class="instance-variable">@name</span>
<span class="line-numbers"><a href="#n3" name="n3">3</a></span>  <span class="instance-variable">@data</span>[<span class="symbol">:text</span>] = value
<span class="line-numbers"><a href="#n4" name="n4">4</a></span>  render
<span class="line-numbers"><a href="#n5" name="n5">5</a></span><span class="keyword">end</span></pre></div>
</div>

    <p>The <span class="caps">HTML</span> representation of the note macro is defined in the <code>macros/reps/html.rb</code> file as follows:</p>
    <div class="CodeRay">
  <div class="code"><pre><span class="line-numbers"><a href="#n1" name="n1">1</a></span>rep <span class="symbol">:note</span> <span class="keyword">do</span> |data|
<span class="line-numbers"><a href="#n2" name="n2">2</a></span>  css_class = data[<span class="symbol">:name</span>].to_s.match(<span class="regexp"><span class="delimiter">/</span><span class="content">[a-z0-9_-]</span><span class="delimiter">/</span><span class="modifier">i</span></span>) ? data[<span class="symbol">:name</span>] : <span class="string"><span class="delimiter">&quot;</span><span class="content">note</span><span class="delimiter">&quot;</span></span>
<span class="line-numbers"><a href="#n3" name="n3">3</a></span>  <span class="string"><span class="delimiter">%{</span><span class="content">&lt;div class=&quot;</span><span class="inline"><span class="inline-delimiter">#{</span>css_class<span class="inline-delimiter">}</span></span><span class="content">&quot;&gt;</span></span>
<span class="line-numbers"><a href="#n4" name="n4">4</a></span><span class="string"><span class="content">&lt;span class=&quot;note-title&quot;&gt;</span><span class="inline"><span class="inline-delimiter">#{</span>data[<span class="symbol">:name</span>].to_s.capitalize<span class="inline-delimiter">}</span></span><span class="content">&lt;/span&gt;</span><span class="inline"><span class="inline-delimiter">#{</span>data[<span class="symbol">:text</span>]<span class="inline-delimiter">}</span></span><span class="content"></span></span>
<span class="line-numbers"><a href="#n5" name="n5">5</a></span><span class="string"><span class="content"></span></span>
<span class="line-numbers"><a href="#n6" name="n6">6</a></span><span class="string"><span class="content">&lt;/div&gt;</span><span class="delimiter">}</span></span>
<span class="line-numbers"><a href="#n7" name="n7">7</a></span><span class="keyword">end</span></pre></div>
</div>

    <p>The HTML5 representation of the note macro, on the other hand, is defined in the <code>macros/reps/html5.rb</code> file as follows:</p>
    <div class="CodeRay">
  <div class="code"><pre><span class="line-numbers"><a href="#n1" name="n1">1</a></span>rep <span class="symbol">:note</span> <span class="keyword">do</span> |data|
<span class="line-numbers"><a href="#n2" name="n2">2</a></span>  css_class = data[<span class="symbol">:name</span>].to_s.match(<span class="regexp"><span class="delimiter">/</span><span class="content">[a-z0-9_-]</span><span class="delimiter">/</span><span class="modifier">i</span></span>) ? data[<span class="symbol">:name</span>] : <span class="string"><span class="delimiter">&quot;</span><span class="content">note</span><span class="delimiter">&quot;</span></span>
<span class="line-numbers"><a href="#n3" name="n3">3</a></span>  <span class="string"><span class="delimiter">%{</span><span class="content">&lt;aside class=&quot;</span><span class="inline"><span class="inline-delimiter">#{</span>css_class<span class="inline-delimiter">}</span></span><span class="content">&quot;&gt;</span></span>
<span class="line-numbers"><a href="#n4" name="n4">4</a></span><span class="string"><span class="content">&lt;span class=&quot;note-title&quot;&gt;</span><span class="inline"><span class="inline-delimiter">#{</span>data[<span class="symbol">:name</span>].to_s.capitalize<span class="inline-delimiter">}</span></span><span class="content">&lt;/span&gt;</span><span class="inline"><span class="inline-delimiter">#{</span>data[<span class="symbol">:text</span>]<span class="inline-delimiter">}</span></span><span class="content"></span></span>
<span class="line-numbers"><a href="#n5" name="n5">5</a></span><span class="string"><span class="content"></span></span>
<span class="line-numbers"><a href="#n6" name="n6">6</a></span><span class="string"><span class="content">&lt;/aside&gt;</span><span class="delimiter">}</span></span>
<span class="line-numbers"><a href="#n7" name="n7">7</a></span><span class="keyword">end</span></pre></div>
</div>

Note the different tags used to render the note.

</section>
							<nav class="navigation"><a href="/glyph/book/extending/internals.html">← A quick look at Glyph's internals</a> | <a href="/glyph/book/index.html">Contents</a> | <a href="/glyph/book/extending/params_attrs.html">Parameters and Attributes →</a></nav>

      </section>
      </article>
    </div>

			
			<footer>
				<section>
          <p>H3RALD Web Site v8.4 &copy; 2004 &mdash; 2014 <em>Fabio Cevasco</em></p>
				</section>
			</footer>
		
    <script type="text/javascript">
        var disqus_shortname = 'h3rald'; 

        (function() {
            var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true;
            dsq.src = '//' + disqus_shortname + '.disqus.com/embed.js';
            (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
        })();
    </script>
    <noscript>Please enable JavaScript to view the <a href="http://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript>
    <a href="http://disqus.com" class="dsq-brlink">comments powered by <span class="logo-disqus">Disqus</span></a>
    
		
    <script>
      hljs.tabReplace = '  ';
      hljs.initHighlightingOnLoad();
    </script>
 <!-- Start Google Analytics --> 
 <script type="text/javascript">
  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', 'UA-18587377-1']);
  _gaq.push(['_trackPageview']);

  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();
 </script> 
 <!-- End Google Analytics --> 
	</body>
</html>