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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

            
              <p class="js-bound-quote">My favorite {{ movie }} quote is "{{ quote }}".</p>  
            
          
!
            
              class BoundNode {
  constructor (node) {
    this.template = node.innerHTML
    this.node = node
  }
  
  update (data) {
    let temp_template = this.template.slice(0)
    this.node.innerHTML = temp_template.replace(/\{\{\s?(\w+)\s?\}\}/g, (match, variable) => {
    return data[variable] || ''
    })
  }
}

class BoundModel {
  constructor (handlers) {
    const callbacks = []
    const data = {
      add_callback: function add_callback (fn) {
        callbacks.push(fn)
      }
    }

    const proxy = new Proxy(data, {
      set: function (target, property, value) {
        target[property] = value
        callbacks.forEach((callback) => callback())
        return true
      }
    })
    
    return proxy 
  }
}




const quotes = [
  "What is the point of owning a race car if you can't drive it?",
  "Give me a scotch, I'm starving.",
  "I'm a huge fan of the way you lose control and turn into an enourmous green rage monster.",
  "I already told you, I don't want to join your super secret boy band.",
  "You know, it's times like these when I realize what a superhero I am."
]

const my_node = new BoundNode(document.querySelector('.js-bound-quote'))
const my_model = new BoundModel()

my_model.add_callback(function () {
  my_node.update(my_model)
})

my_model.movie = 'Iron Man 2'
window.setInterval(function () {
  my_model.quote = quotes[Math.floor(Math.random() * quotes.length)]
}, 1000)




describe('BoundNode', () => {
  let test_node, bound_test_node
  let test_node_text = 'My favorite movie is "{{ movie }}".'
  
  beforeEach(() => {
    test_node = document.createElement('div')
    test_node.innerHTML = test_node_text
    bound_test_node = new BoundNode(test_node)
  })
  
  afterEach(() => {
    test_node = null
    bound_test_node = null
  })
  
  it('remembers the original text as the template', () => {
    expect(bound_test_node.template).toBe(test_node_text)
  })
  
  it('can update the innerHTML', () => {
    const expected_text = 'My favorite movie is "Mrs. Doubtfire".'
    bound_test_node.update({
      movie: 'Mrs. Doubtfire'
    })
    expect(bound_test_node.node.innerHTML).toBe(expected_text)
  })
  
  it('can update the innerHTML multiple times', () => {
    const expected_text_1 = 'My favorite movie is "Mrs. Doubtfire".'
    const expected_text_2 = 'My favorite movie is "The Godfather".'
    bound_test_node.update({
      movie: 'Mrs. Doubtfire'
    })
    expect(bound_test_node.node.innerHTML).toBe(expected_text_1)
    
    bound_test_node.update({
      movie: 'The Godfather'
    })
    expect(bound_test_node.node.innerHTML).toBe(expected_text_2)
  })
})

describe('BoundModel', () => {
  let test_model
  
  beforeEach(() => {
    test_model = new BoundModel()
  })
  
  afterEach(() => {
    test_model = null
  })
  
  it('returns a Proxy instance', () => {
    expect(Object.getPrototypeOf(my_model)).toEqual({})
  })
  
  it('allows setting arbitrary values', () => {
    my_model.foo = 'bar'
    expect(my_model.foo).toBe('bar')
  })
  
  it('can accept a callback for setting values', () => {
    let has_been_called = false
    my_model.add_callback(() => {
      has_been_called = true
    })
    my_model.foo = 'bar'
    
    expect(has_been_called).toBe(true)
  })
  
  it('executes multiple callbacks on #set calls', () => {
    let calls = 0
    my_model.add_callback(function callback_1 () {
      calls++
    })
    my_model.add_callback(function callback_2 () {
      calls++
    })
    expect(calls).toBe(0)
    my_model.foo = 'bar'
    expect(calls).toBe(2)
  })
})

describe('Binding a node to a model', () => {
  it('shows that a model can be bound to a node in a sane way', () => {
    const quote_1 = "What is the point of owning a race car if you can't drive it?"
    const quote_2 = "Give me a scotch, I'm starving."
    
    const test_node = document.createElement('div')
    test_node.innerHTML = '<h1>{{ the_title }}</h1>'
    const test_bound_node = new BoundNode(test_node)
    
    const test_model = new BoundModel()

    test_model.add_callback(function () {
      test_bound_node.update(test_model)
    })

    test_model.the_title = 'Kung Fu Hustle'
    expect(test_node.innerHTML).toBe('<h1>Kung Fu Hustle</h1>')
    
    test_model.the_title = 'The Spy Who Loved Me'
    expect(test_node.innerHTML).toBe('<h1>The Spy Who Loved Me</h1>')
  })
})
            
          
!
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