dyaml/doc/html/api/dyaml.representer.html
2011-10-29 20:43:30 +02:00

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<h1>dyaml.representer</h1>
<!-- Generated by Ddoc from dyaml/representer.d -->
<p>YAML node representer. Prepares YAML nodes for output. A tutorial can be
found <a href="../tutorials/custom_types.html">here</a>.
</p>
<p>Code based on <a href="http://www.pyyaml.org">PyYAML</a>.</p>
<dl><dt class="d_decl">class <a name="RepresenterException"></a><span class="ddoc_psymbol">RepresenterException</span>: dyaml.exception.YAMLException;
</dt>
<dd><p>Exception thrown on Representer errors.</p>
</dd>
<dt class="d_decl">class <a name="Representer"></a><span class="ddoc_psymbol">Representer</span>;
</dt>
<dd><p>Represents YAML nodes of various data types as scalar, sequence and mapping nodes ready for output.
</p>
<p>This class is used to add support for dumping of custom data types.
<br>
It can also override default node formatting styles for output.</p>
<dl><dt class="d_decl">this(bool <b>useDefaultRepresenters</b> = true);
</dt>
<dd><p>Construct a Representer.
</p>
<b>Parameters:</b><div class="pbr"><table class=parms><tr><td valign=top>bool <b>useDefaultRepresenters</b></td>
<td valign=top>Use default representer functions
for default YAML types? This can be
disabled to use custom representer
functions for default types.</td></tr>
</table></div>
</dd>
<dt class="d_decl">@property void <a name="defaultScalarStyle"></a><span class="ddoc_psymbol">defaultScalarStyle</span>(ScalarStyle <b>style</b>);
</dt>
<dd><p>Set default style for scalars. Invalid means the style is chosen automatically.</p>
</dd>
<dt class="d_decl">@property void <a name="defaultCollectionStyle"></a><span class="ddoc_psymbol">defaultCollectionStyle</span>(CollectionStyle <b>style</b>);
</dt>
<dd><p>Set default style for collections. Invalid means the style is chosen automatically. </p>
</dd>
<dt class="d_decl">void <a name="addRepresenter"></a><span class="ddoc_psymbol">addRepresenter</span>(T)(Node function(ref Node, Representer) <b>representer</b>);
</dt>
<dd><p>Add a function to represent nodes with a specific data type.
</p>
<p>The representer function takes references to a Node storing the data
type and to the Representer. It returns the represented node and may
throw a RepresenterException. See the example for more information.
<br>
Only one function may be specified for one data type. Default data
types already have representer functions unless disabled in the
Representer constructor.
</p>
<b>Parameters:</b><div class="pbr"><table class=parms><tr><td valign=top>representer</td>
<td valign=top>Representer function to add.</td></tr>
</table></div>
<b>Examples:</b><div class="pbr">Representing a simple struct:
<pre class="d_code"> <span class="d_keyword">import</span> std.string;
<span class="d_keyword">import</span> yaml;
<span class="d_keyword">struct</span> MyStruct
{
<span class="d_keyword">int</span> x, y, z;
}
Node representMyStruct(<span class="d_keyword">ref</span> Node node, Representer representer)
{
<span class="d_comment">//The node is guaranteed to be MyStruct as we add representer for MyStruct.
</span> <span class="d_keyword">auto</span> value = node.as!MyStruct;
<span class="d_comment">//Using custom scalar format, x:y:z.
</span> <span class="d_keyword">auto</span> scalar = format(value.x, <span class="d_string">":"</span>, value.y, <span class="d_string">":"</span>, value.z);
<span class="d_comment">//Representing as a scalar, with custom tag to specify this data type.
</span> <span class="d_keyword">return</span> representer.representScalar(<span class="d_string">"!mystruct.tag"</span>, scalar);
}
<span class="d_keyword">void</span> main()
{
<span class="d_keyword">auto</span> dumper = Dumper(<span class="d_string">"file.yaml"</span>);
<span class="d_keyword">auto</span> representer = <span class="d_keyword">new</span> Representer;
representer.<span class="d_psymbol">addRepresenter</span>!MyStruct(&amp;representMyStruct);
dumper.representer = representer;
dumper.dump(Node(MyStruct(1,2,3)));
}
</pre>
Representing a class:
<pre class="d_code"> <span class="d_keyword">import</span> std.string;
<span class="d_keyword">import</span> yaml;
<span class="d_keyword">class</span> MyClass
{
<span class="d_keyword">int</span> x, y, z;
<span class="d_keyword">this</span>(<span class="d_keyword">int</span> x, <span class="d_keyword">int</span> y, <span class="d_keyword">int</span> z)
{
<span class="d_keyword">this</span>.x = x;
<span class="d_keyword">this</span>.y = y;
<span class="d_keyword">this</span>.z = z;
}
<span class="d_comment">///We need custom opEquals for node equality, as default opEquals compares references.
</span> <span class="d_keyword">override</span> <span class="d_keyword">bool</span> opEquals(Object rhs)
{
<span class="d_keyword">if</span>(<span class="d_keyword">typeid</span>(rhs) != <span class="d_keyword">typeid</span>(MyClass)){<span class="d_keyword">return</span> <span class="d_keyword">false</span>;}
<span class="d_keyword">auto</span> t = <span class="d_keyword">cast</span>(MyClass)rhs;
<span class="d_keyword">return</span> x == t.x &amp;&amp; y == t.y &amp;&amp; z == t.z;
}
<span class="d_comment">///Useful for Node.as!string .
</span> <span class="d_keyword">override</span> string toString()
{
<span class="d_keyword">return</span> format(<span class="d_string">"MyClass("), x, <span class="d_string">", "</span>, y, <span class="d_string">", "</span>, z, <span class="d_string">"</span>"</span>);
}
}
<span class="d_comment">//Same as representMyStruct.
</span> Node representMyClass(<span class="d_keyword">ref</span> Node node, Representer representer)
{
<span class="d_comment">//The node is guaranteed to be MyClass as we add representer for MyClass.
</span> <span class="d_keyword">auto</span> value = node.as!MyClass;
<span class="d_comment">//Using custom scalar format, x:y:z.
</span> <span class="d_keyword">auto</span> scalar = format(value.x, <span class="d_string">":"</span>, value.y, <span class="d_string">":"</span>, value.z);
<span class="d_comment">//Representing as a scalar, with custom tag to specify this data type.
</span> <span class="d_keyword">return</span> representer.representScalar(<span class="d_string">"!myclass.tag"</span>, scalar);
}
<span class="d_keyword">void</span> main()
{
<span class="d_keyword">auto</span> dumper = Dumper(<span class="d_string">"file.yaml"</span>);
<span class="d_keyword">auto</span> representer = <span class="d_keyword">new</span> Representer;
representer.<span class="d_psymbol">addRepresenter</span>!MyClass(&amp;representMyClass);
dumper.representer = representer;
dumper.dump(Node(<span class="d_keyword">new</span> MyClass(1,2,3)));
}
</pre>
</div>
</dd>
<dt class="d_decl">Node <a name="representScalar"></a><span class="ddoc_psymbol">representScalar</span>(in string <b>tag</b>, string <b>scalar</b>, ScalarStyle <b>style</b> = (ScalarStyle).Invalid);
</dt>
<dd><p>Represent a scalar with specified tag.
</p>
<p>This is used by representer functions that produce scalars.
</p>
<b>Parameters:</b><div class="pbr"><table class=parms><tr><td valign=top>string <b>tag</b></td>
<td valign=top>Tag of the scalar.</td></tr>
<tr><td valign=top>string <b>scalar</b></td>
<td valign=top>Scalar value.</td></tr>
<tr><td valign=top>ScalarStyle <b>style</b></td>
<td valign=top>Style of the scalar. If invalid, default style will be used.
If the node was loaded before, previous style will always be used.</td></tr>
</table></div>
<b>Returns:</b><div class="pbr">The represented node.
</div>
<p><b>Example:</b><br>
<pre class="d_code"> <span class="d_keyword">struct</span> MyStruct
{
<span class="d_keyword">int</span> x, y, z;
}
Node representMyStruct(<span class="d_keyword">ref</span> Node node, Representer representer)
{
<span class="d_keyword">auto</span> value = node.as!MyStruct;
<span class="d_keyword">auto</span> <span class="d_param">scalar</span> = format(value.x, <span class="d_string">":"</span>, value.y, <span class="d_string">":"</span>, value.z);
<span class="d_keyword">return</span> representer.<span class="d_psymbol">representScalar</span>(<span class="d_string">"!mystruct.tag"</span>, <span class="d_param">scalar</span>);
}
</pre>
</p>
</dd>
<dt class="d_decl">Node <a name="representSequence"></a><span class="ddoc_psymbol">representSequence</span>(in string <b>tag</b>, Node[] <b>sequence</b>, CollectionStyle <b>style</b> = (CollectionStyle).Invalid);
</dt>
<dd><p>Represent a sequence with specified tag, representing children first.
</p>
<p>This is used by representer functions that produce sequences.
</p>
<b>Parameters:</b><div class="pbr"><table class=parms><tr><td valign=top>string <b>tag</b></td>
<td valign=top>Tag of the <b>sequence</b>.</td></tr>
<tr><td valign=top>Node[] <b>sequence</b></td>
<td valign=top>Sequence of nodes.</td></tr>
<tr><td valign=top>CollectionStyle <b>style</b></td>
<td valign=top>Style of the sequence. If invalid, default style will be used.
If the node was loaded before, previous style will always be used.</td></tr>
</table></div>
<b>Returns:</b><div class="pbr">The represented node.
</div>
<b>Throws:</b><div class="pbr">RepresenterException if a child could not be represented.
</div>
<p><b>Example:</b><br>
<pre class="d_code"> <span class="d_keyword">struct</span> MyStruct
{
<span class="d_keyword">int</span> x, y, z;
}
Node representMyStruct(<span class="d_keyword">ref</span> Node node, Representer representer)
{
<span class="d_keyword">auto</span> value = node.as!MyStruct;
<span class="d_keyword">auto</span> nodes = [Node(value.x), Node(value.y), Node(value.z)];
<span class="d_comment">//use flow style
</span> <span class="d_keyword">return</span> representer.<span class="d_psymbol">representSequence</span>(<span class="d_string">"!mystruct.tag"</span>, nodes,
CollectionStyle.Flow);
}
</pre>
</p>
</dd>
<dt class="d_decl">Node <a name="representMapping"></a><span class="ddoc_psymbol">representMapping</span>(in string <b>tag</b>, Pair[] <b>pairs</b>, CollectionStyle <b>style</b> = (CollectionStyle).Invalid);
</dt>
<dd><p>Represent a mapping with specified tag, representing children first.
</p>
<p>This is used by representer functions that produce mappings.
</p>
<b>Parameters:</b><div class="pbr"><table class=parms><tr><td valign=top>string <b>tag</b></td>
<td valign=top>Tag of the mapping.</td></tr>
<tr><td valign=top>Pair[] <b>pairs</b></td>
<td valign=top>Key-value pairs of the mapping.</td></tr>
<tr><td valign=top>CollectionStyle <b>style</b></td>
<td valign=top>Style of the mapping. If invalid, default style will be used.
If the node was loaded before, previous style will always be used.</td></tr>
</table></div>
<b>Returns:</b><div class="pbr">The represented node.
</div>
<b>Throws:</b><div class="pbr">RepresenterException if a child could not be represented.
</div>
<p><b>Example:</b><br>
<pre class="d_code"> <span class="d_keyword">struct</span> MyStruct
{
<span class="d_keyword">int</span> x, y, z;
}
Node representMyStruct(<span class="d_keyword">ref</span> Node node, Representer representer)
{
<span class="d_keyword">auto</span> value = node.as!MyStruct;
<span class="d_keyword">auto</span> <span class="d_param">pairs</span> = [Node.Pair(<span class="d_string">"x"</span>, value.x),
Node.Pair(<span class="d_string">"y"</span>, value.y),
Node.Pair(<span class="d_string">"z"</span>, value.z)];
<span class="d_keyword">return</span> representer.<span class="d_psymbol">representMapping</span>(<span class="d_string">"!mystruct.tag"</span>, <span class="d_param">pairs</span>);
}
</pre>
</p>
</dd>
</dl>
</dd>
<dt class="d_decl">Node <a name="representNull"></a><span class="ddoc_psymbol">representNull</span>(ref Node <b>node</b>, Representer <b>representer</b>);
</dt>
<dd><p>Represent a null node as a null YAML value.</p>
</dd>
<dt class="d_decl">Node <a name="representString"></a><span class="ddoc_psymbol">representString</span>(ref Node <b>node</b>, Representer <b>representer</b>);
</dt>
<dd><p>Represent a string node as a string scalar.</p>
</dd>
<dt class="d_decl">Node <a name="representBytes"></a><span class="ddoc_psymbol">representBytes</span>(ref Node <b>node</b>, Representer <b>representer</b>);
</dt>
<dd><p>Represent a bytes node as a binary scalar.</p>
</dd>
<dt class="d_decl">Node <a name="representBool"></a><span class="ddoc_psymbol">representBool</span>(ref Node <b>node</b>, Representer <b>representer</b>);
</dt>
<dd><p>Represent a bool node as a bool scalar.</p>
</dd>
<dt class="d_decl">Node <a name="representLong"></a><span class="ddoc_psymbol">representLong</span>(ref Node <b>node</b>, Representer <b>representer</b>);
</dt>
<dd><p>Represent a long node as an integer scalar.</p>
</dd>
<dt class="d_decl">Node <a name="representReal"></a><span class="ddoc_psymbol">representReal</span>(ref Node <b>node</b>, Representer <b>representer</b>);
</dt>
<dd><p>Represent a real node as a floating point scalar.</p>
</dd>
<dt class="d_decl">Node <a name="representSysTime"></a><span class="ddoc_psymbol">representSysTime</span>(ref Node <b>node</b>, Representer <b>representer</b>);
</dt>
<dd><p>Represent a SysTime node as a timestamp.</p>
</dd>
<dt class="d_decl">Node <a name="representNodes"></a><span class="ddoc_psymbol">representNodes</span>(ref Node <b>node</b>, Representer <b>representer</b>);
</dt>
<dd><p>Represent a sequence node as sequence/set.</p>
</dd>
<dt class="d_decl">Node <a name="representPairs"></a><span class="ddoc_psymbol">representPairs</span>(ref Node <b>node</b>, Representer <b>representer</b>);
</dt>
<dd><p>Represent a mapping node as map/ordered map/pairs.</p>
</dd>
</dl>
</div>
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Copyright &copy; Ferdinand Majerech 2011. Based on <a href="http://www.pyyaml.org">PyYAML</a> by Kirill Simonov. |
Page generated by Autodoc and <a href="http://www.digitalmars.com/d/2.0/ddoc.html">Ddoc</a>.
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