Check component or helper exists

components.default-component.js

import Ember from 'ember';

export default Ember.Component.extend({
});

components.n1-component.js

import Ember from 'ember';

export default Ember.Component.extend({
});

components.n2-component.js

import Ember from 'ember';

export default Ember.Component.extend({
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  emberVersion: Ember.VERSION,
  appName: 'Check component or helper exists'
});

controllers.my-model.js

import Ember from 'ember';

const {computed, getOwner} = Ember;

export default Ember.Controller.extend({
  
  componentName: computed('model.name', function () {
    return `${this.get('model.name')}-component`;
  }),
  
  customComponentExists: computed('componentName', function () {
    const componentName = this.get('componentName');
    const owner = getOwner(this);
    const lookup = owner.lookup('component-lookup:main');
    if (!lookup.componentFor) {
      return !!lookup.lookupFactory(componentName);
    }
    return !!(lookup.componentFor(componentName, owner) || lookup.layoutFor(componentName, owner));
  })
  
});

helpers.helper.js

import Ember from 'ember';

export function helper(params/*, hash*/) {
  return params;
}

export default Ember.Helper.helper(helper);

helpers.is-helper.js

import Ember from 'ember';

const {getOwner} = Ember;

export function compute([name]) {
  	return getOwner(this).hasRegistration(`helper:${name}`);
}

export default Ember.Helper.extend({
	compute
});

helpers.my-helper.js

import Ember from 'ember';

export function myHelper(params/*, hash*/) {
  return params[0];
}

export default Ember.Helper.helper(myHelper);

helpers.my-helper2.js

import Ember from 'ember';

export function compute(params/*, hash*/) {
  return params;
}

export default Ember.Helper.extend({compute});

models.my-model.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  
  name: attr('string')
  
});

router.js

import Ember from 'ember';
import config from './config/environment';

const Router = Ember.Router.extend({
  location: 'none',
  rootURL: config.rootURL
});

Router.map(function() {
  this.route('my-model', {path: '/:model_id'});
});

export default Router;

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  
  beforeModel() {
    this.get('store').push({
      data: [
        {id: '1', type: 'my-model', attributes: {name: 'n1'}},
        {id: '2', type: 'my-model', attributes: {name: 'n2'}},
        {id: '3', type: 'my-model', attributes: {name: 'n3'}},
        {id: '4', type: 'my-model', attributes: {name: 'n4'}}
      ]
    });
  },
  
  model() {
    return this.get('store').peekAll('my-model');
  }
  
});

routes.my-model.js

import Ember from 'ember';

export default Ember.Route.extend({
  
  model(model_id) {
    return this.get('store').peekRecord('my-model', model_id);
  }
  
});

templates.application.hbs

<h1>{{appName}}</h1>
<p>Ember: <strong>{{emberVersion}}</strong></p>

<p><code>my-helper</code> exists: {{if (is-helper "my-helper") "true" "false"}}</p>

<p><code>my-helper2</code> exists: {{if (is-helper "my-helper2") "true" "false"}}</p>

<p><code>helper</code> exists: {{if (is-helper "helper") "true" "false"}}</p>


<ul>
{{#each model as |myModel|}}
	<li>{{#link-to "my-model" myModel}}{{myModel.name}}{{/link-to}}</li>
{{/each}}
</ul>
{{outlet}}

templates.components.default-component.hbs

Default component with model {{myModel.id}}

templates.components.n1-component.hbs

Custom component for model with name `n1`

templates.components.n2-component.hbs

Unique component for `n2` model

templates.components.n3-component.hbs

Just a template for model `n3` with id = {{myModel.id}}

templates.my-model.hbs

{{#if customComponentExists}}
	{{component componentName myModel=model}}
{{else}}
	{{default-component myModel=model}}
{{/if}}

twiddle.json

{
  "version": "0.10.4",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "release",
    "ember-data": "2.7.0",
    "ember-template-compiler": "release"
  },
  "addons": {}
}