I have an external SVG file which contains the following SVG definition:
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 150" ><path class="st0" fill="#FFFFFF" d="M50,145.5C40.6,131.6,2.5,73.4,2.5,50C2.5,23.8,23.8,2.5,50,2.5S97.5,23.8,97.5,50C97.5,73.4,59.4,131.6,50,145.5z"/><path class="st1" fill="#000000" d="m50 5c24.8 0 45 20.2 45 45 0 19.5-29.4 67.7-45 91.1-15.6-23.4-45-71.6-45-91.1 0-24.8 20.2-45 45-45m0-5c-27.6 0-50 22.4-50 50s50 100 50 100 50-72.4 50-100-22.4-50-50-50z"/><circle fill="#ffbf00" cx="50" cy="50" r="27.5"/><path d="m50 25c13.8 0 25 11.2 25 25s-11.2 25-25 25-25-11.2-25-25 11.2-25 25-25m0-5c-16.6 0-30 13.4-30 30s13.4 30 30 30 30-13.4 30-30-13.4-30-30-30z"/></svg>
The SVG has multiple paths, so for me to be able to change colours of individual paths I need to be able to load the SVG file contents into a Javascript variable like this:
var svgSource = '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 150" ><path class="st0" fill="#FFFFFF" d="M50,145.5C40.6,131.6,2.5,73.4,2.5,50C2.5,23.8,23.8,2.5,50,2.5S97.5,23.8,97.5,50C97.5,73.4,59.4,131.6,50,145.5z"/><path class="st1" fill="#000000" d="m50 5c24.8 0 45 20.2 45 45 0 19.5-29.4 67.7-45 91.1-15.6-23.4-45-71.6-45-91.1 0-24.8 20.2-45 45-45m0-5c-27.6 0-50 22.4-50 50s50 100 50 100 50-72.4 50-100-22.4-50-50-50z"/><circle fill="#ffbf00" cx="50" cy="50" r="27.5"/><path d="m50 25c13.8 0 25 11.2 25 25s-11.2 25-25 25-25-11.2-25-25 11.2-25 25-25m0-5c-16.6 0-30 13.4-30 30s13.4 30 30 30 30-13.4 30-30-13.4-30-30-30z"/></svg>';
Then I can use conditional statements to alter the colours e.g.
switch(centerId) {
case 1:
svgSource = svgSource.replace("#ffbf00", "#005D00");
break;
case 2:
svgSource = svgSource.replace("#ffbf00", "#A20000");
break;
case 3:
svgSource = svgSource.replace("#ffbf00", "#ffbf00");
break;
}
I could define and use the inline SVG code hard coded into the Javascript as shown, but for maintenance and continuity it would be much better to use existing, centralised, external SVG files.
How can I load the contents of the SVG file into a javascript variable/object?
One solution is to load the svg image by setting the innerHTML property of an arbitrary container to your svg string.
This then gives you two options: firstly, for heavy changes, you have access to each path as part of the DOM and can maniulate them using javascript. This simply requires making a reference to container.children[0]; Alternatively, for simple changes such as colour changes, it makes each element directly targetable by style rules where you can specify colours in the usual way.
The snippet illustrates adding the svg to the dom using your string, and resets some colours with simple style rules. Making a reference for changes using javascript is shown commented at the foot of the code.
let svgSource = '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 150" ><path class="st0" fill="#FFFFFF" d="M50,145.5C40.6,131.6,2.5,73.4,2.5,50C2.5,23.8,23.8,2.5,50,2.5S97.5,23.8,97.5,50C97.5,73.4,59.4,131.6,50,145.5z"/><path class="st1" fill="#000000" d="m50 5c24.8 0 45 20.2 45 45 0 19.5-29.4 67.7-45 91.1-15.6-23.4-45-71.6-45-91.1 0-24.8 20.2-45 45-45m0-5c-27.6 0-50 22.4-50 50s50 100 50 100 50-72.4 50-100-22.4-50-50-50z"/><circle fill="#ffbf00" cx="50" cy="50" r="27.5"/><path d="m50 25c13.8 0 25 11.2 25 25s-11.2 25-25 25-25-11.2-25-25 11.2-25 25-25m0-5c-16.6 0-30 13.4-30 30s13.4 30 30 30 30-13.4 30-30-13.4-30-30-30z"/></svg>';
const container = document.getElementsByTagName('div')[0];
container.innerHTML = svgSource;
// for js manipulation:
// svgObject = container.children[0];div {
width: 50%;
}
.st0 {
fill: red;
}
.st1 {
fill: yellow;
}
circle {
fill: green;
}<div>
</div>CSS Styling
Try using CSS to style the paths instead of replacing parts of source code.
Concept code example, using the style attribute of svg elements to apply some CSS:
"use strict";
const svg = document.querySelector("svg");
const paths = svg.querySelectorAll("path");
paths[0].style = "fill: #FF0000;"
svg.querySelector("circle").style = "fill: rebeccapurple";svg {
height: 150px;
width: 100px;
}<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 150" ><path class="st0" fill="#FFFFFF" d="M50,145.5C40.6,131.6,2.5,73.4,2.5,50C2.5,23.8,23.8,2.5,50,2.5S97.5,23.8,97.5,50C97.5,73.4,59.4,131.6,50,145.5z"/><path class="st1" fill="#000000" d="m50 5c24.8 0 45 20.2 45 45 0 19.5-29.4 67.7-45 91.1-15.6-23.4-45-71.6-45-91.1 0-24.8 20.2-45 45-45m0-5c-27.6 0-50 22.4-50 50s50 100 50 100 50-72.4 50-100-22.4-50-50-50z"/><circle fill="#ffbf00" cx="50" cy="50" r="27.5"/><path d="m50 25c13.8 0 25 11.2 25 25s-11.2 25-25 25-25-11.2-25-25 11.2-25 25-25m0-5c-16.6 0-30 13.4-30 30s13.4 30 30 30 30-13.4 30-30-13.4-30-30-30z"/></svg>Potentially you could improve on this by writing svg source that expects to be styled by CSS instead of being over-ridden by style attribute values.
See also: How to use external SVG in HTML?
Getting the source of an external SVG file
An external svg file can be included in HTML using a pair of <object> tags. For example if "svg-file.svg" is in the same directory as the HTML file:
<object type="image/svg+xml" id="mySVG"
data="svg-file.svg"
width="100"
height="150"
></object>
Subject to security policies: the svg file must be from the same domain and served from a network or localhost server - due to blanket security restriction placed on local files, the source of svg files loaded using the file:// protocol. can't be accessed.
Picking up the svg source is a bit obscure. This worked for me after page load, using the above HTML:
window.onload = ()=> {
console.log("loaded");
const svgObject = document.querySelector("#mySVG");
const svg = svgObject.getSVGDocument().documentElement;
const svgSource = svg.outerHTML;
console.log("svgElement, tag name '%s' ", svg.tagName, svg);
console.log("svgSource: ", svgSource);
console.log("path.st0: ", svg.querySelector('.st0'));
};