vue-prom

Vue promise wrapper component

About

The goal of this component is to simplify rendering logic based on promise state (pending / fulfilled, rejected). The component keeps track of the promise's state and proposes slots to render content accordingly.

You should avoid this component when:

• You need to store the result of the promise (i.e to send it back later or if it is required for a computed property).
• You need to make a function call inside of the promise callback (i.e store the result in Vuex or trigger your notification library).

Installation

NPM

npm install --save vue-prom

npm package link

CDN

<script src="https://unpkg.com/vue-prom@latest"></script>

Usage

With vue-prom we would write the following:

<template>
  <div>
      <vue-prom :promise="api.getUser()">
          <div slot="pending">
              Loading user...
          </div>
          <div slot="then" slot-scope="{result}">
              Hello {{ result.firstName }} {{ result.lastName }}
          </div>
          <div slot="catch" slot-scope="{error}">
              {{ error.message }}
          </div>
      </vue-prom>
  </div>
</template>

<script>
import VueProm from 'vue-prom';
import api from './api';
export default {
  data() {
    api
  },
  components: {
      VueProm
  }
};
</script>

Instead of:

<template>
    <div>
        <div v-if="loading">
            Loading user...
        </div>
        <div v-else-if="error">
            {{ error.message }}
        </div>
        <div v-else>
            Hello {{ result.firstName }} {{ result.lastName }}
        </div>
    </div>
</template>

<script>
import api from './api';
export default {
  created() {
    this.loading = true;
    this.error = null;
    api
      .getUser()
      .then(result => (this.user = result))
      .catch(error => (this.error = error))
      .finally(_ => (this.loading = false));
  },
  data() {
    return {
      loading: false,
      user: null
    };
  }
};
</script>

Alternatively, to keep the template concise, we can omit the 'pending' and 'catch' slots altogether and rely on the default labels provided by the component instead.

<template>
  <div>
      <vue-prom :promise="api.getUser()">
          <div slot="then" slot-scope="{result}">
              Hello {{ result.firstName }} {{ result.lastName }}
          </div>
      </vue-prom>
  </div>
</template>

Props

• promise: required, the promise to resolve.
• refresh: refresh trigger.

The component watches both the promise and refresh props, the promise will automatically re-execute when the value of either of these changes.

Slots

All slots are optional.

| Name | Visible when | Slot type(s) | If absent | |----------|---------------------------|--------------------|---------------------------| | pending | The promise is pending | Regular only | A span with 'Loading...' | | catch | The promise was rejected | Regular and scoped | A span with 'Error' | | then | The promise was fulfilled | Regular and scoped | A span with 'Loaded' |

Data exposed by scoped slots:

• Scoped 'catch' slot exposes the 'error' object.
• Scoped 'then' slot exposes the 'result' object.