Ember CLI: custom input helper

问题

I'm trying to extend Ember's TextField with UrlField so that if someone forgets to include http://, it does it for them.

Here's my View:

views/input-url.js

import Ember from 'ember';

export default Ember.TextField.extend({

    type: 'url',

    didInsertElement: function() {
        this._super.apply(this, arguments);
        this.formatValue();
    },

    onValueChange: function() {
        this.formatValue();
    }.observes('value'),

    formatValue: function() {
        var pattern = /^https{0,1}:\/\/[A-Za-z0-9]+\.[A-Za-z0-9]+/g;
        if (pattern.test(this.get('value')))
          return;

        if (!pattern.test('http://' + this.get('value')))
          return;

        this.set('value', 'http://' + this.get('value'));
    }

});

If I use it in my template like this, it works fine:

{{view "input-url" value=url}}

I prefer to use custom view helpers, so I created this (following the guide at the bottom of this page: http://guides.emberjs.com/v1.11.0/templates/writing-helpers/):

helpers/input-url.js

import Ember from 'ember';
import InputUrl from '../views/input-url';

export default Ember.Handlebars.makeBoundHelper(InputUrl);

Now trying to render this in my template doesn't work:

{{input-url value=url}}

I've also tried different permutations of this, including what's shown in the guide Ember.Handlebars.makeBoundHelper('input-url', InputUrl); (which throws an error), but I can't seem to get my input field to show up. What am I doing wrong?

回答1:

Not sure what you are doing wrong with your view helper, but there is a much simpler solution: take advantage of the fact that Ember.Textfield is a component. http://emberjs.com/api/classes/Ember.TextField.html

Simply move views/input-url.js to components/input-url.js and get rid of your view helper.

Then {{input-url value=url}} should work automatically.

回答2:

If you want do to this using a helper, you cannot extend Ember.TextField because extends Ember.Component and is not a Handlebars helper.

The way to do this using a helper would actually be simpler. Since you are using Ember-CLI, you can create a helper called "input-url" with the command ember g helper input-url and the only code you would need is the code within your formatValue() function:

helpers/input-url.js

// define patter globally so it's not recreated each time the function is called    
var pattern = /^https{0,1}:\/\/[A-Za-z0-9]+\.[A-Za-z0-9]+/g;

export function inputUrl(value) {
    if (pattern.test(value)) {
        return value;
    }

    if (!pattern.test('http://' + value)) {
        return value;
    }

    return 'http://' + value;
};

export default Ember.Handlebars.makeBoundHelper(inputUrl);

And you can use it like:

{{input-url PASS_YOUR_URL_HERE}}

Where the value you pass will be the value of the value variable within the helper.

You could also create a component, as @Gaurav suggested, using the exact code you have above, just in components/input-url.js instead and delete the helper cause it is not necessary anymore. You also have to edit the corresponding template of the component if you want it to display the value with a single handlebars expression:

templates/components/input-url.hbs

{{value}}

The usage with a component would be:

{{input-url value=PASS_YOUR_URL_HERE}}

来源：https://stackoverflow.com/questions/29506064/ember-cli-custom-input-helper

标签

ember.js

ember-cli