Angular + SVG：如何从字符串动态加载模板

Question

In Angular, it's possible to use SVG as component template. I wonder if there is a way to convert a SVG content (string loaded from server) into a component template, including the possibility to bind some properties to it (ie, <tspan [attr.color]="textColor"...>{{myText}}</tspan> ).

I've made some tests and all that I got was to load and render the SVG content, but the binds are not working. Instead, they are rendered as strings.

I know that if put the SVG content in a file and reference it in component's templateUrl setting, it works. For example:

...
@Component({
   templateUrl: './content.svg'
})
export class MyComponent {
   ...
}
...

I've already tested it. However, I need to load the SVG from a server (it cannot be a static file or hard coded in source-code).

Can anyone help me?

Update

Just to clarify a little bit...

Consider the following component:

@Component({
    selector: 'my-component',
    template: `<div [innerHtml]="mySvg"></div>`
})
export class MyComponent {
    textColor: string;
    myText: string;
    mySvg: string;

    constructor() {
        this.textColor = '#ff0000';
        this.myText = 'Just testing';
    }

    loadSvg() {
        // here goes some logic to request the SVG string from server
        // ...
       this.mySvg = response;
    }
}

Now, consider that the server returned the following string:

<svg>
    <tspan [attr.color]="textColor">{{myText}}</tspan>
</svg>

I would like the SVG to be rendered and the interpolations to work as well (making it possible to change the text and color).

Is it possible?

Answer 1

If you stick to native standard Javascript template literal notation: ${x}

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals

 `string ${property} string string ${property} string` 

You can create a tagged template function that does all the replacing of property values for you

Here the template string is the innerHTML , properties as attributes

When you make up your own template syntax (or use 3rd party) You will have to add a lot more boilerplate code or libraries to parse that String

 <svg-from-template cx="30" cy="30"> <rect x='0' y='0' width='100%' height='100%' fill='${bgcolor}'></rect> <circle cx='${cx}' cy='${cy}' r='10%' fill='${fill}'></circle> </svg-from-template> <svg-from-template bgcolor="lightgreen" cx="70" cy="70" fill="green"> <rect x='0' y='0' width='100%' height='100%' fill='${bgcolor}'></rect> <circle cx='${cx}' cy='${cy}' r='20%' fill='${fill}'></circle> </svg-from-template> <script> customElements.define( "svg-from-template", class extends HTMLElement { connectedCallback() { function parseTemplate(templateString, templateData = {}) { return new Function( // create Function AND return the executed function result "templateProps", [ "let f = ( " + Object.keys(templateData).join(",") + " ) =>", "`" + templateString + "`", "return f(...Object.values(templateProps))", ].join("\n") )(templateData); // execute tagged template function } setTimeout(() => { // wait till all innerHTML is parsed by the Browser let templateData = [...this.attributes].reduce((acc, attr) => { acc[attr.name] = attr.value; // copy element attributes to {} object return acc; }, { /*default object*/ bgcolor: 'pink', fill: 'red' }); let templateString = this.innerHTML; // OR read from file/server/universe this.innerHTML = "<svg mlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'>" + parseTemplate(templateString, templateData) + "</svg>"; }); } } ); </script> <style> svg { width: 180px; /* SO snippet window height */ } </style>