Improve <SvgIcon> to make it output svg node and optimize performance (#23570)

Before, the Vue `<SvgIcon>` always outputs DOM nodes like: 

```html
<span class="outer-class">
    <svg class="class-name-defined" ...></svg>
</span>
```

The `span` is redundant and I guess such layout and the inconsistent
`class/class-name` attributes would cause bugs sooner or later.

This PR makes the `<SvgIcon>` clear, and it's faster than before,
because it doesn't need to parse the whole SVG string.

Before: 

<details>

![image](https://user-images.githubusercontent.com/2114189/226156474-ce2c57cd-b869-486a-b75b-1eebdac8cdf7.png)

</details>

After:

![image](https://user-images.githubusercontent.com/2114189/226155774-108f49ed-7512-40c3-94a2-a6e8da18063d.png)

---------

Co-authored-by: silverwind <me@silverwind.io>
This commit is contained in:
wxiaoguang 2023-03-23 11:24:16 +08:00 committed by GitHub
parent 1d35fa0e78
commit 389e83f7eb
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9 changed files with 77 additions and 24 deletions

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@ -105,13 +105,32 @@ export function svg(name, size = 16, className = '') {
const document = parser.parseFromString(svgs[name], 'image/svg+xml');
const svgNode = document.firstChild;
if (size !== 16) svgNode.setAttribute('width', String(size));
if (size !== 16) svgNode.setAttribute('height', String(size));
// filter array to remove empty string
if (size !== 16) {
svgNode.setAttribute('width', String(size));
svgNode.setAttribute('height', String(size));
}
if (className) svgNode.classList.add(...className.split(/\s+/).filter(Boolean));
return serializer.serializeToString(svgNode);
}
export function svgParseOuterInner(name) {
const svgStr = svgs[name];
if (!svgStr) throw new Error(`Unknown SVG icon: ${name}`);
// parse the SVG string to 2 parts
// * svgInnerHtml: the inner part of the SVG, will be used as the content of the <svg> VNode
// * svgOuter: the outer part of the SVG, including attributes
// the builtin SVG contents are clean, so it's safe to use `indexOf` to split the content:
// eg: <svg outer-attributes>${svgInnerHtml}</svg>
const p1 = svgStr.indexOf('>'), p2 = svgStr.lastIndexOf('<');
if (p1 === -1 || p2 === -1) throw new Error(`Invalid SVG icon: ${name}`);
const svgInnerHtml = svgStr.slice(p1 + 1, p2);
const svgOuterHtml = svgStr.slice(0, p1 + 1) + svgStr.slice(p2);
const svgDoc = parser.parseFromString(svgOuterHtml, 'image/svg+xml');
const svgOuter = svgDoc.firstChild;
return {svgOuter, svgInnerHtml};
}
export const SvgIcon = {
name: 'SvgIcon',
props: {
@ -120,6 +139,32 @@ export const SvgIcon = {
className: {type: String, default: ''},
},
render() {
return h('span', {innerHTML: svg(this.name, this.size, this.className)});
const {svgOuter, svgInnerHtml} = svgParseOuterInner(this.name);
// https://vuejs.org/guide/extras/render-function.html#creating-vnodes
// the `^` is used for attr, set SVG attributes like 'width', `aria-hidden`, `viewBox`, etc
const attrs = {};
for (const attr of svgOuter.attributes) {
if (attr.name === 'class') continue;
attrs[`^${attr.name}`] = attr.value;
}
attrs[`^width`] = this.size;
attrs[`^height`] = this.size;
// make the <SvgIcon class="foo" class-name="bar"> classes work together
const classes = [];
for (const cls of svgOuter.classList) {
classes.push(cls);
}
// TODO: drop the `className/class-name` prop in the future, only use "class" prop
if (this.className) {
classes.push(...this.className.split(/\s+/).filter(Boolean));
}
// create VNode
return h('svg', {
...attrs,
class: classes,
innerHTML: svgInnerHtml,
});
},
};