286 lines
14 KiB
Plaintext
Generated
286 lines
14 KiB
Plaintext
Generated
<!DOCTYPE html>
|
|
<html>
|
|
<head>
|
|
<meta charset="utf-8">
|
|
<title>Go by Example: XML</title>
|
|
<link rel=stylesheet href="site.css">
|
|
</head>
|
|
<script>
|
|
onkeydown = (e) => {
|
|
|
|
if (e.key == "ArrowLeft") {
|
|
window.location.href = 'json';
|
|
}
|
|
|
|
|
|
if (e.key == "ArrowRight") {
|
|
window.location.href = 'time';
|
|
}
|
|
|
|
}
|
|
</script>
|
|
<body>
|
|
<div class="example" id="xml">
|
|
<h2><a href="./">Go by Example</a>: XML</h2>
|
|
|
|
<table>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>Go offers built-in support for XML and XML-like
|
|
formats with the <code>encoding.xml</code> package.</p>
|
|
|
|
</td>
|
|
<td class="code empty leading">
|
|
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
<a href="http://play.golang.org/p/qd9Ii_3AW0s">
|
|
<img title="Run code" class="run" src="data:image/png;base64,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" />
|
|
</a>
|
|
<div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre><span class="kn">import</span> <span class="p">(</span>
|
|
<span class="s">"encoding/xml"</span>
|
|
<span class="s">"fmt"</span>
|
|
<span class="p">)</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>This type will be mapped to XML. Similarly to the
|
|
JSON examples, field tags contain directives for the
|
|
encoder and decoder. Here we use some special features
|
|
of the XML package: the <code>XMLName</code> field name dictates
|
|
the name of the XML element representing this struct;
|
|
<code>id,attr</code> means that the <code>Id</code> field is an XML
|
|
<em>attribute</em> rather than a nested element.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre><span class="kd">type</span> <span class="nx">Plant</span> <span class="kd">struct</span> <span class="p">{</span>
|
|
<span class="nx">XMLName</span> <span class="nx">xml</span><span class="p">.</span><span class="nx">Name</span> <span class="s">`xml:"plant"`</span>
|
|
<span class="nx">Id</span> <span class="kt">int</span> <span class="s">`xml:"id,attr"`</span>
|
|
<span class="nx">Name</span> <span class="kt">string</span> <span class="s">`xml:"name"`</span>
|
|
<span class="nx">Origin</span> <span class="p">[]</span><span class="kt">string</span> <span class="s">`xml:"origin"`</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre><span class="kd">func</span> <span class="p">(</span><span class="nx">p</span> <span class="nx">Plant</span><span class="p">)</span> <span class="nx">String</span><span class="p">()</span> <span class="kt">string</span> <span class="p">{</span>
|
|
<span class="k">return</span> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Sprintf</span><span class="p">(</span><span class="s">"Plant id=%v, name=%v, origin=%v"</span><span class="p">,</span>
|
|
<span class="nx">p</span><span class="p">.</span><span class="nx">Id</span><span class="p">,</span> <span class="nx">p</span><span class="p">.</span><span class="nx">Name</span><span class="p">,</span> <span class="nx">p</span><span class="p">.</span><span class="nx">Origin</span><span class="p">)</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">main</span><span class="p">()</span> <span class="p">{</span>
|
|
<span class="nx">coffee</span> <span class="o">:=</span> <span class="o">&</span><span class="nx">Plant</span><span class="p">{</span><span class="nx">Id</span><span class="p">:</span> <span class="mi">27</span><span class="p">,</span> <span class="nx">Name</span><span class="p">:</span> <span class="s">"Coffee"</span><span class="p">}</span>
|
|
<span class="nx">coffee</span><span class="p">.</span><span class="nx">Origin</span> <span class="p">=</span> <span class="p">[]</span><span class="kt">string</span><span class="p">{</span><span class="s">"Ethiopia"</span><span class="p">,</span> <span class="s">"Brazil"</span><span class="p">}</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>Emit XML representing our plant; using
|
|
<code>MarshalIndent</code> to produce a more
|
|
human-readable output.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre> <span class="nx">out</span><span class="p">,</span> <span class="nx">_</span> <span class="o">:=</span> <span class="nx">xml</span><span class="p">.</span><span class="nx">MarshalIndent</span><span class="p">(</span><span class="nx">coffee</span><span class="p">,</span> <span class="s">" "</span><span class="p">,</span> <span class="s">" "</span><span class="p">)</span>
|
|
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nb">string</span><span class="p">(</span><span class="nx">out</span><span class="p">))</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>To add a generic XML header to the output, append
|
|
it explicitly.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">xml</span><span class="p">.</span><span class="nx">Header</span> <span class="o">+</span> <span class="nb">string</span><span class="p">(</span><span class="nx">out</span><span class="p">))</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>Use <code>Unmarhshal</code> to parse a stream of bytes with XML
|
|
into a data structure. If the XML is malformed or
|
|
cannot be mapped onto Plant, a descriptive error
|
|
will be returned.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre> <span class="kd">var</span> <span class="nx">p</span> <span class="nx">Plant</span>
|
|
<span class="k">if</span> <span class="nx">err</span> <span class="o">:=</span> <span class="nx">xml</span><span class="p">.</span><span class="nx">Unmarshal</span><span class="p">(</span><span class="nx">out</span><span class="p">,</span> <span class="o">&</span><span class="nx">p</span><span class="p">);</span> <span class="nx">err</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
|
|
<span class="nb">panic</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
|
|
<span class="p">}</span>
|
|
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">p</span><span class="p">)</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre> <span class="nx">tomato</span> <span class="o">:=</span> <span class="o">&</span><span class="nx">Plant</span><span class="p">{</span><span class="nx">Id</span><span class="p">:</span> <span class="mi">81</span><span class="p">,</span> <span class="nx">Name</span><span class="p">:</span> <span class="s">"Tomato"</span><span class="p">}</span>
|
|
<span class="nx">tomato</span><span class="p">.</span><span class="nx">Origin</span> <span class="p">=</span> <span class="p">[]</span><span class="kt">string</span><span class="p">{</span><span class="s">"Mexico"</span><span class="p">,</span> <span class="s">"California"</span><span class="p">}</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>The <code>parent>child>plant</code> field tag tells the encoder
|
|
to nest all <code>plant</code>s under <code><parent><child>...</code></p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre> <span class="kd">type</span> <span class="nx">Nesting</span> <span class="kd">struct</span> <span class="p">{</span>
|
|
<span class="nx">XMLName</span> <span class="nx">xml</span><span class="p">.</span><span class="nx">Name</span> <span class="s">`xml:"nesting"`</span>
|
|
<span class="nx">Plants</span> <span class="p">[]</span><span class="o">*</span><span class="nx">Plant</span> <span class="s">`xml:"parent>child>plant"`</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre> <span class="nx">nesting</span> <span class="o">:=</span> <span class="o">&</span><span class="nx">Nesting</span><span class="p">{}</span>
|
|
<span class="nx">nesting</span><span class="p">.</span><span class="nx">Plants</span> <span class="p">=</span> <span class="p">[]</span><span class="o">*</span><span class="nx">Plant</span><span class="p">{</span><span class="nx">coffee</span><span class="p">,</span> <span class="nx">tomato</span><span class="p">}</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code">
|
|
|
|
<div class="highlight"><pre> <span class="nx">out</span><span class="p">,</span> <span class="nx">_</span> <span class="p">=</span> <span class="nx">xml</span><span class="p">.</span><span class="nx">MarshalIndent</span><span class="p">(</span><span class="nx">nesting</span><span class="p">,</span> <span class="s">" "</span><span class="p">,</span> <span class="s">" "</span><span class="p">)</span>
|
|
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nb">string</span><span class="p">(</span><span class="nx">out</span><span class="p">))</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
</table>
|
|
|
|
<table>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code">
|
|
|
|
<div class="highlight"><pre><span class="gp">$</span> go run xml.go
|
|
<span class="go"> <plant id="27"></span>
|
|
<span class="go"> <name>Coffee</name></span>
|
|
<span class="go"> <origin>Ethiopia</origin></span>
|
|
<span class="go"> <origin>Brazil</origin></span>
|
|
<span class="go"> </plant></span>
|
|
<span class="go"><?xml version="1.0" encoding="UTF-8"?></span>
|
|
<span class="go"> <plant id="27"></span>
|
|
<span class="go"> <name>Coffee</name></span>
|
|
<span class="go"> <origin>Ethiopia</origin></span>
|
|
<span class="go"> <origin>Brazil</origin></span>
|
|
<span class="go"> </plant></span>
|
|
<span class="go">Plant id=27, name=Coffee, origin=[Ethiopia Brazil]</span>
|
|
<span class="go"> <nesting></span>
|
|
<span class="go"> <parent></span>
|
|
<span class="go"> <child></span>
|
|
<span class="go"> <plant id="27"></span>
|
|
<span class="go"> <name>Coffee</name></span>
|
|
<span class="go"> <origin>Ethiopia</origin></span>
|
|
<span class="go"> <origin>Brazil</origin></span>
|
|
<span class="go"> </plant></span>
|
|
<span class="go"> <plant id="81"></span>
|
|
<span class="go"> <name>Tomato</name></span>
|
|
<span class="go"> <origin>Mexico</origin></span>
|
|
<span class="go"> <origin>California</origin></span>
|
|
<span class="go"> </plant></span>
|
|
<span class="go"> </child></span>
|
|
<span class="go"> </parent></span>
|
|
<span class="go"> </nesting></span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
</table>
|
|
|
|
|
|
<p class="next">
|
|
Next example: <a href="time">Time</a>.
|
|
</p>
|
|
|
|
<p class="footer">
|
|
by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/xml">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
|
|
</p>
|
|
</div>
|
|
</body>
|
|
</html>
|