I have a svg in a string, like this:
const svgString = (color) => `<svg height="150" width="500">
<ellipse cx="240" cy="100" rx="220" ry="30" style="fill:${color}" />
<ellipse cx="220" cy="70" rx="190" ry="20" style="fill:lime" />
<ellipse cx="210" cy="45" rx="170" ry="15" style="fill:yellow" />
</svg>`;
Please consider that's an example svg, the real one is a little bit larger and more complex, so do not pay a lot of attentiton to that example.
What I want is to draw that SVG string in a canvas. I have tried something like this:
const canvas = document.createElement('canvas');
canvas.width = 18;
canvas.height = 25;
const ctx = canvas.getContext('2d');
const path = new Path2D(svgString('red'));
ctx.drawImage(path, 0, 0, 18, 25);
But that fails with the following error:
"<a class='gotoLine' href='#52:5'>52:5</a> Uncaught TypeError: Failed to execute 'drawImage' on 'CanvasRenderingContext2D': The provided value is not of type '(CSSImageValue or HTMLCanvasElement or HTMLImageElement or HTMLVideoElement or ImageBitmap or OffscreenCanvas or SVGImageElement or VideoFrame)'."
Any idea how to solve this?
const svgString = (color) => `<svg height="150" width="500">
<ellipse cx="240" cy="100" rx="220" ry="30" style="fill:${color}" />
<ellipse cx="220" cy="70" rx="190" ry="20" style="fill:lime" />
<ellipse cx="210" cy="45" rx="170" ry="15" style="fill:yellow" />
</svg>`;
const canvas = document.createElement('canvas');
canvas.width = 18;
canvas.height = 25;
const ctx = canvas.getContext('2d');
const path = new Path2D(svgString('red'));
ctx.drawImage(path, 0, 0, 18, 25);
CodePudding user response:
Here you have two examples. In both examples I added the SVG namespace to the string, be cause it is a separate XML/SVG document and not haft of the HTML.
In the first example I just create a data URL and insert that as the source of an image object. Here you need to set the width and the height.
In the second example I used Blob and the function URL.createObjectURL().
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
const svgString = (color) => `<svg xmlns="http://www.w3.org/2000/svg" height="150" width="500">
<ellipse cx="240" cy="100" rx="220" ry="30" style="fill:${color}" />
<ellipse cx="220" cy="70" rx="190" ry="20" style="fill:lime" />
<ellipse cx="210" cy="45" rx="170" ry="15" style="fill:yellow" />
</svg>`;
var img = new Image();
img.width = 500;
img.height = 150;
img.addEventListener('load', e => {
ctx.drawImage(e.target, 0, 0);
});
img.src = `data:image/svg xml,${svgString('red')}`;
<canvas width="500" height="150" id="canvas"></canvas>
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
const svgString = (color) => `<svg xmlns="http://www.w3.org/2000/svg" height="150" width="500">
<ellipse cx="240" cy="100" rx="220" ry="30" style="fill:${color}" />
<ellipse cx="220" cy="70" rx="190" ry="20" style="fill:lime" />
<ellipse cx="210" cy="45" rx="170" ry="15" style="fill:yellow" />
</svg>`;
var svg = new Blob([svgString('red')], {
type: "image/svg xml;charset=utf-8"
});
var url = URL.createObjectURL(svg);
var img = new Image();
img.addEventListener('load', e => {
ctx.drawImage(e.target, 0, 0);
URL.revokeObjectURL(url);
});
img.src = url;
<canvas width="500" height="150" id="canvas"></canvas>