Event example from Polymer 3 devguide “Listener on outside elements” throws an exception










1















I've created example for the snippets from the Polymer 3 dev guide. This example doesn't compile as _myLocationListener is not defined and it is used in the constructor. The listener is also not defined inside the dev guide snippet.



How this._myLocationListener property should be initialized.



import html, PolymerElement from '@polymer/polymer/polymer-element.js';

/**
* @customElement
* @polymer
*/
class XcustomElementEventHandlingApp extends PolymerElement
static get template()
return html`
<style>
:host
display: block;
border: dotted;
background: aliceblue;

</style>
<h2>Hello [[prop1]]!</h2>
<button on-click="handleClick">Kick Me</button>
<div id="child-el-01">Please, check the logs in Console (dev tools).</div>
`;


static get properties()
return
prop1:
type: String,
value: 'xcustom-element-event-handling-app'

;


constructor()
super();

this._boundListener = this._myLocationListener.bind(this);


ready()
super.ready();
this.addEventListener('click', this._onClick);

const childElement = this.shadowRoot.getElementById('child-el-01');
childElement.addEventListener('click', this._onClick.bind(this));
childElement.addEventListener('mouseover', event => this._onHover(event));


console.log('(this, the) custom element added to DOM.');


handleClick()
console.log('Ow!');


_onClick(event)
this._makeCoffee();


_makeCoffee()
console.log('in _makeCoffee()')


_onHover(event)
console.log('_onHover(ev) called');
console.log(JSON.stringify(event));


connectedCallback()
super.connectedCallback();
window.addEventListener('hashchange', this._boundListener);


disconnectedCallback()
super.disconnectedCallback();
window.removeEventListener('hashchange', this._boundListener);



window.customElements.define('xcustom-element-event-handling-app', XcustomElementEventHandlingApp);


package.json:




"name": "xcustom-element-event-handling",
"description": "event handling demo. From dev guide.",
"dependencies":
"@polymer/polymer": "^3.0.0"
,
"devDependencies":
"@webcomponents/webcomponentsjs": "^2.0.0",
"wct-browser-legacy": "^1.0.0"




Following exception is thrown:



Uncaught TypeError: this._myLocationListener.bind is not a function
at new XcustomElementEventHandlingApp (xcustom-element-event-handling-app.js:36)









share|improve this question
























  • stackoverflow.com/help/how-to-ask

    – Eugene Mihaylin
    Nov 16 '18 at 9:01











  • Hope that latest edit did improve the question. I'm just started with Polymer 3 and am trying to run the dev. guide examples.

    – Tihomir
    Nov 16 '18 at 9:26











  • please add concrete code sample and error to the question body

    – Eugene Mihaylin
    Nov 16 '18 at 9:27












  • Thanks! Example code and link to snippet are added to question body.

    – Tihomir
    Nov 16 '18 at 14:34















1















I've created example for the snippets from the Polymer 3 dev guide. This example doesn't compile as _myLocationListener is not defined and it is used in the constructor. The listener is also not defined inside the dev guide snippet.



How this._myLocationListener property should be initialized.



import html, PolymerElement from '@polymer/polymer/polymer-element.js';

/**
* @customElement
* @polymer
*/
class XcustomElementEventHandlingApp extends PolymerElement
static get template()
return html`
<style>
:host
display: block;
border: dotted;
background: aliceblue;

</style>
<h2>Hello [[prop1]]!</h2>
<button on-click="handleClick">Kick Me</button>
<div id="child-el-01">Please, check the logs in Console (dev tools).</div>
`;


static get properties()
return
prop1:
type: String,
value: 'xcustom-element-event-handling-app'

;


constructor()
super();

this._boundListener = this._myLocationListener.bind(this);


ready()
super.ready();
this.addEventListener('click', this._onClick);

const childElement = this.shadowRoot.getElementById('child-el-01');
childElement.addEventListener('click', this._onClick.bind(this));
childElement.addEventListener('mouseover', event => this._onHover(event));


console.log('(this, the) custom element added to DOM.');


handleClick()
console.log('Ow!');


_onClick(event)
this._makeCoffee();


_makeCoffee()
console.log('in _makeCoffee()')


_onHover(event)
console.log('_onHover(ev) called');
console.log(JSON.stringify(event));


connectedCallback()
super.connectedCallback();
window.addEventListener('hashchange', this._boundListener);


disconnectedCallback()
super.disconnectedCallback();
window.removeEventListener('hashchange', this._boundListener);



window.customElements.define('xcustom-element-event-handling-app', XcustomElementEventHandlingApp);


package.json:




"name": "xcustom-element-event-handling",
"description": "event handling demo. From dev guide.",
"dependencies":
"@polymer/polymer": "^3.0.0"
,
"devDependencies":
"@webcomponents/webcomponentsjs": "^2.0.0",
"wct-browser-legacy": "^1.0.0"




Following exception is thrown:



Uncaught TypeError: this._myLocationListener.bind is not a function
at new XcustomElementEventHandlingApp (xcustom-element-event-handling-app.js:36)









share|improve this question
























  • stackoverflow.com/help/how-to-ask

    – Eugene Mihaylin
    Nov 16 '18 at 9:01











  • Hope that latest edit did improve the question. I'm just started with Polymer 3 and am trying to run the dev. guide examples.

    – Tihomir
    Nov 16 '18 at 9:26











  • please add concrete code sample and error to the question body

    – Eugene Mihaylin
    Nov 16 '18 at 9:27












  • Thanks! Example code and link to snippet are added to question body.

    – Tihomir
    Nov 16 '18 at 14:34













1












1








1








I've created example for the snippets from the Polymer 3 dev guide. This example doesn't compile as _myLocationListener is not defined and it is used in the constructor. The listener is also not defined inside the dev guide snippet.



How this._myLocationListener property should be initialized.



import html, PolymerElement from '@polymer/polymer/polymer-element.js';

/**
* @customElement
* @polymer
*/
class XcustomElementEventHandlingApp extends PolymerElement
static get template()
return html`
<style>
:host
display: block;
border: dotted;
background: aliceblue;

</style>
<h2>Hello [[prop1]]!</h2>
<button on-click="handleClick">Kick Me</button>
<div id="child-el-01">Please, check the logs in Console (dev tools).</div>
`;


static get properties()
return
prop1:
type: String,
value: 'xcustom-element-event-handling-app'

;


constructor()
super();

this._boundListener = this._myLocationListener.bind(this);


ready()
super.ready();
this.addEventListener('click', this._onClick);

const childElement = this.shadowRoot.getElementById('child-el-01');
childElement.addEventListener('click', this._onClick.bind(this));
childElement.addEventListener('mouseover', event => this._onHover(event));


console.log('(this, the) custom element added to DOM.');


handleClick()
console.log('Ow!');


_onClick(event)
this._makeCoffee();


_makeCoffee()
console.log('in _makeCoffee()')


_onHover(event)
console.log('_onHover(ev) called');
console.log(JSON.stringify(event));


connectedCallback()
super.connectedCallback();
window.addEventListener('hashchange', this._boundListener);


disconnectedCallback()
super.disconnectedCallback();
window.removeEventListener('hashchange', this._boundListener);



window.customElements.define('xcustom-element-event-handling-app', XcustomElementEventHandlingApp);


package.json:




"name": "xcustom-element-event-handling",
"description": "event handling demo. From dev guide.",
"dependencies":
"@polymer/polymer": "^3.0.0"
,
"devDependencies":
"@webcomponents/webcomponentsjs": "^2.0.0",
"wct-browser-legacy": "^1.0.0"




Following exception is thrown:



Uncaught TypeError: this._myLocationListener.bind is not a function
at new XcustomElementEventHandlingApp (xcustom-element-event-handling-app.js:36)









share|improve this question
















I've created example for the snippets from the Polymer 3 dev guide. This example doesn't compile as _myLocationListener is not defined and it is used in the constructor. The listener is also not defined inside the dev guide snippet.



How this._myLocationListener property should be initialized.



import html, PolymerElement from '@polymer/polymer/polymer-element.js';

/**
* @customElement
* @polymer
*/
class XcustomElementEventHandlingApp extends PolymerElement
static get template()
return html`
<style>
:host
display: block;
border: dotted;
background: aliceblue;

</style>
<h2>Hello [[prop1]]!</h2>
<button on-click="handleClick">Kick Me</button>
<div id="child-el-01">Please, check the logs in Console (dev tools).</div>
`;


static get properties()
return
prop1:
type: String,
value: 'xcustom-element-event-handling-app'

;


constructor()
super();

this._boundListener = this._myLocationListener.bind(this);


ready()
super.ready();
this.addEventListener('click', this._onClick);

const childElement = this.shadowRoot.getElementById('child-el-01');
childElement.addEventListener('click', this._onClick.bind(this));
childElement.addEventListener('mouseover', event => this._onHover(event));


console.log('(this, the) custom element added to DOM.');


handleClick()
console.log('Ow!');


_onClick(event)
this._makeCoffee();


_makeCoffee()
console.log('in _makeCoffee()')


_onHover(event)
console.log('_onHover(ev) called');
console.log(JSON.stringify(event));


connectedCallback()
super.connectedCallback();
window.addEventListener('hashchange', this._boundListener);


disconnectedCallback()
super.disconnectedCallback();
window.removeEventListener('hashchange', this._boundListener);



window.customElements.define('xcustom-element-event-handling-app', XcustomElementEventHandlingApp);


package.json:




"name": "xcustom-element-event-handling",
"description": "event handling demo. From dev guide.",
"dependencies":
"@polymer/polymer": "^3.0.0"
,
"devDependencies":
"@webcomponents/webcomponentsjs": "^2.0.0",
"wct-browser-legacy": "^1.0.0"




Following exception is thrown:



Uncaught TypeError: this._myLocationListener.bind is not a function
at new XcustomElementEventHandlingApp (xcustom-element-event-handling-app.js:36)






javascript web-component polymer-3.x






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 16 '18 at 13:33







Tihomir

















asked Nov 16 '18 at 8:47









TihomirTihomir

748




748












  • stackoverflow.com/help/how-to-ask

    – Eugene Mihaylin
    Nov 16 '18 at 9:01











  • Hope that latest edit did improve the question. I'm just started with Polymer 3 and am trying to run the dev. guide examples.

    – Tihomir
    Nov 16 '18 at 9:26











  • please add concrete code sample and error to the question body

    – Eugene Mihaylin
    Nov 16 '18 at 9:27












  • Thanks! Example code and link to snippet are added to question body.

    – Tihomir
    Nov 16 '18 at 14:34

















  • stackoverflow.com/help/how-to-ask

    – Eugene Mihaylin
    Nov 16 '18 at 9:01











  • Hope that latest edit did improve the question. I'm just started with Polymer 3 and am trying to run the dev. guide examples.

    – Tihomir
    Nov 16 '18 at 9:26











  • please add concrete code sample and error to the question body

    – Eugene Mihaylin
    Nov 16 '18 at 9:27












  • Thanks! Example code and link to snippet are added to question body.

    – Tihomir
    Nov 16 '18 at 14:34
















stackoverflow.com/help/how-to-ask

– Eugene Mihaylin
Nov 16 '18 at 9:01





stackoverflow.com/help/how-to-ask

– Eugene Mihaylin
Nov 16 '18 at 9:01













Hope that latest edit did improve the question. I'm just started with Polymer 3 and am trying to run the dev. guide examples.

– Tihomir
Nov 16 '18 at 9:26





Hope that latest edit did improve the question. I'm just started with Polymer 3 and am trying to run the dev. guide examples.

– Tihomir
Nov 16 '18 at 9:26













please add concrete code sample and error to the question body

– Eugene Mihaylin
Nov 16 '18 at 9:27






please add concrete code sample and error to the question body

– Eugene Mihaylin
Nov 16 '18 at 9:27














Thanks! Example code and link to snippet are added to question body.

– Tihomir
Nov 16 '18 at 14:34





Thanks! Example code and link to snippet are added to question body.

– Tihomir
Nov 16 '18 at 14:34












1 Answer
1






active

oldest

votes


















1














At the above example, the main idea is if you like to listen an event from outside of this custom element. You may set up a listener inside connectedCallback and remove it with disconnectedCallback, then assign a function in the element after event occure.
Something like



index.html :



<!DOCTYPE html>
<html lang="en">
<head>
<script src="https://unpkg.com/@webcomponents/webcomponentsjs/webcomponents-loader.js"></script>
<script type="module" src="x-custom.js"></script>
</head>
<body>
<button>This button not in the element</button>
<x-custom></x-custom>
</body>
</html>


x-custom.js:



import PolymerElement, html from 'https://unpkg.com/@polymer/polymer@3.0.0-pre.12/polymer-element.js';

class XCustom extends PolymerElement
static get template()
return html`<h2>Hello </h2> `;


constructor()
super();
this._boundListener = this._myLocationListener.bind(this);


connectedCallback()
super.connectedCallback();
window.addEventListener('click', this._boundListener);


disconnectedCallback()
super.disconnectedCallback();
window.removeEventListener('click', this._boundListener);

_myLocationListener()
alert('This click comes from index.html - out of this element')



window.customElements.define('x-custom', XCustom);


DEMO






share|improve this answer























  • Thank you very much! Additionally we can add an id to button to listen only button clicks: window.document.getElementById('xyz1').addEventListener('click', this._boundListener);

    – Tihomir
    Nov 17 '18 at 6:34











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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









1














At the above example, the main idea is if you like to listen an event from outside of this custom element. You may set up a listener inside connectedCallback and remove it with disconnectedCallback, then assign a function in the element after event occure.
Something like



index.html :



<!DOCTYPE html>
<html lang="en">
<head>
<script src="https://unpkg.com/@webcomponents/webcomponentsjs/webcomponents-loader.js"></script>
<script type="module" src="x-custom.js"></script>
</head>
<body>
<button>This button not in the element</button>
<x-custom></x-custom>
</body>
</html>


x-custom.js:



import PolymerElement, html from 'https://unpkg.com/@polymer/polymer@3.0.0-pre.12/polymer-element.js';

class XCustom extends PolymerElement
static get template()
return html`<h2>Hello </h2> `;


constructor()
super();
this._boundListener = this._myLocationListener.bind(this);


connectedCallback()
super.connectedCallback();
window.addEventListener('click', this._boundListener);


disconnectedCallback()
super.disconnectedCallback();
window.removeEventListener('click', this._boundListener);

_myLocationListener()
alert('This click comes from index.html - out of this element')



window.customElements.define('x-custom', XCustom);


DEMO






share|improve this answer























  • Thank you very much! Additionally we can add an id to button to listen only button clicks: window.document.getElementById('xyz1').addEventListener('click', this._boundListener);

    – Tihomir
    Nov 17 '18 at 6:34















1














At the above example, the main idea is if you like to listen an event from outside of this custom element. You may set up a listener inside connectedCallback and remove it with disconnectedCallback, then assign a function in the element after event occure.
Something like



index.html :



<!DOCTYPE html>
<html lang="en">
<head>
<script src="https://unpkg.com/@webcomponents/webcomponentsjs/webcomponents-loader.js"></script>
<script type="module" src="x-custom.js"></script>
</head>
<body>
<button>This button not in the element</button>
<x-custom></x-custom>
</body>
</html>


x-custom.js:



import PolymerElement, html from 'https://unpkg.com/@polymer/polymer@3.0.0-pre.12/polymer-element.js';

class XCustom extends PolymerElement
static get template()
return html`<h2>Hello </h2> `;


constructor()
super();
this._boundListener = this._myLocationListener.bind(this);


connectedCallback()
super.connectedCallback();
window.addEventListener('click', this._boundListener);


disconnectedCallback()
super.disconnectedCallback();
window.removeEventListener('click', this._boundListener);

_myLocationListener()
alert('This click comes from index.html - out of this element')



window.customElements.define('x-custom', XCustom);


DEMO






share|improve this answer























  • Thank you very much! Additionally we can add an id to button to listen only button clicks: window.document.getElementById('xyz1').addEventListener('click', this._boundListener);

    – Tihomir
    Nov 17 '18 at 6:34













1












1








1







At the above example, the main idea is if you like to listen an event from outside of this custom element. You may set up a listener inside connectedCallback and remove it with disconnectedCallback, then assign a function in the element after event occure.
Something like



index.html :



<!DOCTYPE html>
<html lang="en">
<head>
<script src="https://unpkg.com/@webcomponents/webcomponentsjs/webcomponents-loader.js"></script>
<script type="module" src="x-custom.js"></script>
</head>
<body>
<button>This button not in the element</button>
<x-custom></x-custom>
</body>
</html>


x-custom.js:



import PolymerElement, html from 'https://unpkg.com/@polymer/polymer@3.0.0-pre.12/polymer-element.js';

class XCustom extends PolymerElement
static get template()
return html`<h2>Hello </h2> `;


constructor()
super();
this._boundListener = this._myLocationListener.bind(this);


connectedCallback()
super.connectedCallback();
window.addEventListener('click', this._boundListener);


disconnectedCallback()
super.disconnectedCallback();
window.removeEventListener('click', this._boundListener);

_myLocationListener()
alert('This click comes from index.html - out of this element')



window.customElements.define('x-custom', XCustom);


DEMO






share|improve this answer













At the above example, the main idea is if you like to listen an event from outside of this custom element. You may set up a listener inside connectedCallback and remove it with disconnectedCallback, then assign a function in the element after event occure.
Something like



index.html :



<!DOCTYPE html>
<html lang="en">
<head>
<script src="https://unpkg.com/@webcomponents/webcomponentsjs/webcomponents-loader.js"></script>
<script type="module" src="x-custom.js"></script>
</head>
<body>
<button>This button not in the element</button>
<x-custom></x-custom>
</body>
</html>


x-custom.js:



import PolymerElement, html from 'https://unpkg.com/@polymer/polymer@3.0.0-pre.12/polymer-element.js';

class XCustom extends PolymerElement
static get template()
return html`<h2>Hello </h2> `;


constructor()
super();
this._boundListener = this._myLocationListener.bind(this);


connectedCallback()
super.connectedCallback();
window.addEventListener('click', this._boundListener);


disconnectedCallback()
super.disconnectedCallback();
window.removeEventListener('click', this._boundListener);

_myLocationListener()
alert('This click comes from index.html - out of this element')



window.customElements.define('x-custom', XCustom);


DEMO







share|improve this answer












share|improve this answer



share|improve this answer










answered Nov 16 '18 at 18:20









HakanCHakanC

2,3443814




2,3443814












  • Thank you very much! Additionally we can add an id to button to listen only button clicks: window.document.getElementById('xyz1').addEventListener('click', this._boundListener);

    – Tihomir
    Nov 17 '18 at 6:34

















  • Thank you very much! Additionally we can add an id to button to listen only button clicks: window.document.getElementById('xyz1').addEventListener('click', this._boundListener);

    – Tihomir
    Nov 17 '18 at 6:34
















Thank you very much! Additionally we can add an id to button to listen only button clicks: window.document.getElementById('xyz1').addEventListener('click', this._boundListener);

– Tihomir
Nov 17 '18 at 6:34





Thank you very much! Additionally we can add an id to button to listen only button clicks: window.document.getElementById('xyz1').addEventListener('click', this._boundListener);

– Tihomir
Nov 17 '18 at 6:34



















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