Vue.js

The Practical Guide

@N_Tepluhina

 What will we learn today? 

- Components structure and contracts

- Abstracting and reusing logic

- Component composition

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 When your project grows...

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Components structure and contracts

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One-way data flow

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One-way data flow

- DO NOT mutate props

- ...even if props are objects

- ...even if they passed 6 levels deep

- avoid pass method as a prop, emit an event instead

@N_Tepluhina

My cool modal component

<script>
export default {
  props: {
    headerText: String,
    descriptionText: String,
  }
}
</script>

<template>
  <div class="modal">
    <h2>{{ headerText }}</h2>
    <p>{{ descriptionText }}</p>
    <div class="modal-actions">
      <button @click="$emit('modal-ok')">OK</button>
    </div>
  </div>
</template>

Can we render a logo if there is no header text?

@N_Tepluhina

My cool modal component

<script>
export default {
  props: {
    headerText: String,
    descriptionText: String,
  }
}
</script>

<template>
  <div class="modal">
    <h2 v-if="headerText">{{ headerText }}</h2>
    <img v-else src="https://picsum.photos/100">
    <p>{{ descriptionText }}</p>
    <div class="modal-actions">
      <button @click="$emit('modal-ok')">OK</button>
    </div>
  </div>
</template>

Can we change a logo link? We need different logos for different modals

@N_Tepluhina

My cool modal component

<script>
export default {
  props: {
    headerText: String,
    descriptionText: String,
    logoUrl: String
  }
}
</script>

<template>
  <div class="modal">
    <h2 v-if="headerText">{{ headerText }}</h2>
    <img v-else :src="logoUrl">
    <p>{{ descriptionText }}</p>
    <div class="modal-actions">
      <button @click="$emit('modal-ok')">OK</button>
    </div>
  </div>
</template>

For some modals we need a cancel button!

@N_Tepluhina

My cool modal component

<script>
export default {
  props: {
    headerText: String,
    descriptionText: String,
    logoUrl: String,
    isCancelShown: Boolean
  }
};
</script>

<template>
  <div class="modal">
    <h2 v-if="headerText">{{ headerText }}</h2>
    <img v-else :src="logoUrl">
    <p>{{ descriptionText }}</p>
    <div class="modal-actions">
      <button v-if="isCancelShown" @click="$emit('modal-cancel')">Cancel</button>
      <button @click="$emit('modal-ok')">OK</button>
    </div>
  </div>
</template>

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My cool modal component

We also want different colors for 'OK' button

Can we render more than simple text on description?

We would like an icon to specify the modal type...

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My NOT COOL ANYMORE modal component

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Slots

<script>
export default {
  props: {
    headerText: String,
    descriptionText: String,
    logoUrl: String,
    isCancelShown: Boolean
  }
};
</script>

<template>
  <div class="modal">
    <h2 v-if="headerText">{{ headerText }}</h2>
    <img v-else :src="logoUrl">
    <p>{{ descriptionText }}</p>
    <div class="modal-actions">
      <button v-if="isCancelShown" @click="$emit('modal-cancel')">Cancel</button>
      <button @click="$emit('modal-ok')">OK</button>
    </div>
  </div>
</template>

@N_Tepluhina

Slots

<script>
export default {
  props: {
    descriptionText: String,
    logoUrl: String,
    isCancelShown: Boolean
  }
};
</script>

<template>
  <div class="modal">
    <slot></slot>
    <p>{{ descriptionText }}</p>
    <div class="modal-actions">
      <button v-if="isCancelShown" @click="$emit('modal-cancel')">Cancel</button>
      <button @click="$emit('modal-ok')">OK</button>
    </div>
  </div>
</template>

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Named slots

<script>
export default {}
</script>

<template>
  <div>
    <slot name="header"></slot>
    <slot name="description"></slot>
    <div class="modal-actions">
      <slot name="actions"></slot>
    </div>
  </div>
</template>

@N_Tepluhina

Named slots

<!-- parent component -->

<template>
  <my-modal>
    <template #header>My header</template>
    <template #description>
      <h4>
        Here is my awesome description
      </h4>
      <span>Description text goes here</span>
    </template>
    <template #actions>
      <button v-if="isCancelShown" @click="onCancel">Cancel</button>
      <button @click="onSubmit" :style="{backgroundColor: okColor}">OK</button>
    </template>
  </my-modal>
</template>

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Scoped slots

<!-- MyModal.vue -->

<script>
export default {
  data() {
    return {
      loading: true
    };
  },
  created() {
    setTimeout(() => (this.loading = false), 3000);
  }
};
</script>

<template>
  <div class="modal">
    <slot name="header" :loading="loading"></slot>
    <slot name="description"></slot>
    <div class="modal-actions">
      <slot name="actions"></slot>
    </div>
  </div>
</template>

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Scoped slots

<!-- App.vue -->

<my-modal>
  <template #header="{ loading }">
    <h2>You have joined Vue workshop!
      <template v-if="loading">Wait for it...</template>
    </h2>
  </template>
  ...
</my-modal>

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Flat

Nested

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Flat

Nested

- easy to navigate

- easy to refactor

- good for smaller projects

- more structured

- test near component

- components folder is not bloated for bigger application

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Base/Shared components (atoms)

- buttons

- inputs

- modals

- ...everything you can imagine in component library

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Add a prefix!

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Make them as dumb as possible

- no global state bindings

- minimum local state

- props, emitted events and slots

Q & A

@N_Tepluhina

Vue.js: The Practical Guide

By Natalia Tepluhina

Vue.js: The Practical Guide

Smashing Workshop - Day 2

  • 831