Can't extend from custom element

[admosity]

I am trying to extend a simple custom element using version 1.5.9:

xtag.register('x-span', {
  mixins: ['dataPoint', 'dataSource'],
  content: '<span></span>',
  methods: {
    render() {
      // some render logic...
    },
  },
});

xtag.register('x-money-span', {
  extends: 'x-span',
  methods: {
    render() {
      const span = xtag.queryChildren(this, 'span')[0];
      let data = this.data;
      let currency = this.getAttribute('currency');
      if (currency) {
        span.textContent = `${SomeDataService.getData('currency')[currency].symbol}${this.data}`;
      }
    },
  },
});

However, I am getting the following error:

Uncaught NotSupportedError: Failed to execute 'registerElement' on 'Document': Registration failed for type 'x-money-span'. The tag name specified in 'extends' is a custom element name. Use inheritance instead.

😢

[csuwildcat]

That's not an X-Tag thing, it's how the standard Custom Elements API works.
Is there a reason you can't inherent from the previous custom element's
prototype using standard means?
On May 23, 2016 2:40 PM, "admosity" notifications@github.com wrote:

I am trying to extend a simple custom element using version 1.5.9:

xtag.register('x-span', {
mixins: ['dataPoint', 'dataSource'],
content: '',
methods: {
render() {
// some render logic...
},
},
});

xtag.register('x-money-span', {
extends: 'x-span',
methods: {
render() {
const span = xtag.queryChildren(this, 'span')[0];
let data = this.data;
let currency = this.getAttribute('currency');
if (currency) {
span.textContent = ${SomeDataService.getData('currency')[currency].symbol}${this.data};
}
},
},
});

However, I am getting the following error:

Uncaught NotSupportedError: Failed to execute 'registerElement' on 'Document': Registration failed for type 'x-money-span'. The tag name specified in 'extends' is a custom element name. Use inheritance instead.

😢

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#156

[admosity]

Thanks for the quick reply!

I am fairly new to the library and to the Custom Elements API in general... What would be the correct way of referencing a registered tag?

I tried doing:

  xtag.register('x-money-span', {
  prototype: xtag.tags['x-span'].compiled.prototype,
  methods: {
    render() {
      const span = xtag.queryChildren(this, 'span')[0];
      let data = this.data;
      let currency = this.getAttribute('currency');
      if (currency) {
        span.textContent = `${SomeDataService.getData('currency')[currency].symbol}${this.data}`;
      }
    },
  },
});

But that doesn't seem to be working.

[admosity]

It's not pretty, but this works:

import SomeDataService from '../core/SomeDataService';

let proto = Object.create(xtag.tags['x-span'].compiled.prototype);
let originalRender = proto.render.value;
proto.render = {
  enumberable: true,
  value: function () {
    originalRender.call(this);
    const span = xtag.queryChildren(this, 'span')[0];
    let data = this.data;
    let currency = this.getAttribute('currency');
    if (currency) {
      span.textContent = `${SomeDataService.getData(`currency.${currency}.symbol`)}${this.data}`;
    }
  },
};
xtag.register('x-money-span', {
  mixins: ['dataPoint', 'dataSource'],
  prototype: proto,
});

Is there a better way of doing this?

[csuwildcat]

The code below should work, but I haven't tested it. Let me know, I want to make sure we are doing the most we can for your use-case.

var xSpan = xtag.register('x-span', {
  mixins: ['dataPoint', 'dataSource'],
  content: '<span></span>',
  methods: {
    render() {
      // some render logic
    },
  },
});

xtag.register('x-money-span', {
  prototype: xSpan.prototype,
  methods: {
    render: function() {
        xSpan.prototype.render.call(this, ARGS_HERE);
        // x-money-span render logic
    },
  }
});

[admosity]

Ah, I did exactly that. Except for some reason the mixins and content don't propagate through and I have to redefine them. Here's my code:

import XSpan from './Span';
import SomeDataService from '../core/SomeDataService';

xtag.register('x-money-span', {
  mixins: ['dataPoint', 'dataSource'],
  prototype: XSpan.prototype,
  content: '<span></span>',
  methods: {
    render() {
      XSpan.prototype.render.call(this)
      const span = xtag.queryChildren(this, 'span')[0];
      let data = this.data;
      let currency = this.getAttribute('currency');
      if (currency) {
        span.textContent = `${SomeDataService.getData(`currency.${currency}.symbol`)}${this.data}`;
      }
    }
  }
});

[csuwildcat]

I will setup a test case for this to figure out what's going on. I
definitely want to make sure the mixins and content carry over.
On May 23, 2016 6:26 PM, "admosity" notifications@github.com wrote:

Ah, I did exactly that. Except for some reason the mixins and content
don't propagate through and I have to redefine them. Here's my code:

import XSpan from './Span';import SomeDataService from '../core/SomeDataService';
xtag.register('x-money-span', {
mixins: ['dataPoint', 'dataSource'],
prototype: XSpan.prototype,
content: '',
methods: {
render() {
XSpan.prototype.render.call(this)
const span = xtag.queryChildren(this, 'span')[0];
let data = this.data;
let currency = this.getAttribute('currency');
if (currency) {
span.textContent = ${SomeDataService.getData(currency.${currency}.symbol)}${this.data};
}
}
}
});

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#156 (comment)

[admosity]

Added test cases in #157

[csuwildcat]

@admosity can you create a live test case using JSBin or something that shows your breaking example?

[admosity]

@csuwildcat I actually just replicated the issue. The lifecycle hooks were not triggering from the mixins. I have added a new test case to the PR #157

[csuwildcat]

@admosity I confirmed your issue, and am actively working on this.

[csuwildcat]

@admosity I have a brand new build up on master that I have not pushed out to release yet. I believe it accounts for all forms of composition and inheritance, including mixins. Can you please test it and let me know?

[admosity]

@csuwildcat sorry, been swamped with work and have not gotten around to this. I will let you know when I do. Thanks for getting it covered!

[csuwildcat]

I am closing this out for now given the changes seem to be working well for everyone - please reopen if you have any further issues with this.

[armartinez]

I'm extending a custom element by using the prototype property specified by csuwildcat (would be nice if extends also worked for custom elements).
I noticed that when calling an overwritten method the base and the overwritten methods are called in order, is this the expected behaviour ? I would expect that only the latter gets called.