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@MSCAU
Last active August 29, 2015 14:01
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Polling SVG TEXT and TSPAN width
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<style>
body {
font-family: sans-serif;
font-size: 0.7em;
}
pre {
position: absolute;
top: 0px;
left: 180px;
font-size: 1.3em;
}
svg {
shape-rendering: crispEdges;
border: 3px solid black;
}
table {
border-collapse: collapse;
}
th, td {
padding: 2px;
}
td:nth-child(3) {
text-align: right;
}
text {
font-size: 2em;
}
</style>
</head>
<body>
<svg width="150" height="150">
<text id="test1" y="50">test1</text>
<text id="test2" y="100">
<tspan id="test3">test3</tspan>
</text>
<tspan id="test4">test4</tspan>
</svg>
<pre>
&lt;svg width="150" height="150"&gt;
&lt;text id="test1" y="50"&gt;test1&lt;/text&gt;
&lt;text id="test2" y="100"&gt;
&lt;tspan id="test3"&gt;test3&lt;/tspan&gt;
&lt;/text&gt;
&lt;tspan id="test4"&gt;test4&lt;/tspan&gt;
&lt;/svg&gt;
</pre>
<p></p>
<table border="1">
<tr>
<th>id</th><th>Code</th><th>Result</th><th>Note</th>
</tr>
<tr>
<td>test1</td><td>document.getElementById("test1").getBBox().width</td><td id="result1a"></td><td>Integer in Chrome; Float in IE and Firefox.</td>
</tr>
<tr>
<td>test2</td><td>document.getElementById("test2").getBBox().width</td><td id="result2a"></td><td>Integer in Chrome; Float in IE and Firefox.</td>
</tr>
<tr>
<td>test3</td><td>document.getElementById("test3").getBBox().width</td><td id="result3a"></td><td>IE and Firefox can't get the BBox of a TSPAN and error out.</td>
</tr>
<tr>
<td>test4</td><td>document.getElementById("test4").getBBox().width</td><td id="result4a"></td><td>IE and Firefox can't get the BBox of a TSPAN whether it's inside a TEXT or not.</td>
</tr>
<tr><td colspan="4"></td></tr>
<tr>
<td>test1</td><td>document.getElementById("test1").getBoundingClientRect().width</td><td id="result1b"></td><td>Integer in IE, Chrome and Safari. Same width as "test2" in Chrome eventhough 1 is narrower than 2.</td>
</tr>
<tr>
<td>test2</td><td>document.getElementById("test2").getBoundingClientRect().width</td><td id="result2b"></td><td>Integer in IE, Chrome and Safari. Same width as "test1" in Chrome eventhough 2 is wider than 1.</td>
</tr>
<tr>
<td>test3</td><td>document.getElementById("test3").getBoundingClientRect().width</td><td id="result3b"></td><td>Integer in Chrome and Safari.</td>
</tr>
<tr>
<td>test4</td><td>document.getElementById("test4").getBoundingClientRect().width</td><td id="result4b"></td><td>Integer in Chrome and Safari.</td>
</tr>
<tr><td colspan="4"></td></tr>
<tr>
<td>test1</td><td>document.getElementById("test1").getComputedTextLength()</td><td id="result1c"></td><td>Integer in Chrome; Float in IE and Firefox.</td>
</tr>
<tr>
<td>test2</td><td>document.getElementById("test2").getComputedTextLength()</td><td id="result2c"></td><td>Integer in Chrome; Float in IE and Firefox.</td>
</tr>
<tr>
<td>test3</td><td>document.getElementById("test3").getComputedTextLength()</td><td id="result3c"></td><td>Integer in Chrome; Float in IE and Firefox.</td>
</tr>
<tr>
<td>test4</td><td>document.getElementById("test4").getComputedTextLength()</td><td id="result4c"></td><td>A TSPAN which is not in a TEXT has no width</td>
</tr>
</table>
<script>
document.body.onload = function () {
document.getElementById("result1a").innerHTML = document.getElementById("test1").getBBox().width;
document.getElementById("result2a").innerHTML = document.getElementById("test2").getBBox().width;
try {
document.getElementById("result3a").innerHTML = document.getElementById("test3").getBBox().width;
}
catch(e) {
document.getElementById("result3a").innerHTML = e.message;
}
try {
document.getElementById("result4a").innerHTML = document.getElementById("test4").getBBox().width;
}
catch(e) {
document.getElementById("result4a").innerHTML = e.message;
}
document.getElementById("result1b").innerHTML = document.getElementById("test1").getBoundingClientRect().width;
document.getElementById("result2b").innerHTML = document.getElementById("test2").getBoundingClientRect().width;
document.getElementById("result3b").innerHTML = document.getElementById("test3").getBoundingClientRect().width;
document.getElementById("result4b").innerHTML = document.getElementById("test4").getBoundingClientRect().width;
document.getElementById("result1c").innerHTML = document.getElementById("test1").getComputedTextLength();
document.getElementById("result2c").innerHTML = document.getElementById("test2").getComputedTextLength();
document.getElementById("result3c").innerHTML = document.getElementById("test3").getComputedTextLength();
document.getElementById("result4c").innerHTML = document.getElementById("test4").getComputedTextLength();
}
</script>
</body>
</html>
@MSCAU
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MSCAU commented May 10, 2014

Manipulating text in SVG is not easy, especially when you don't know the correct Javascript syntax. Text doesn't wrap natively in SVG so it's essentially to understand how to poll string widths to workaround this limitation.

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