The Vuex store variable is being accessed prior to being populated with information retrieved from the API

Question

The Vuex store variable is being accessed prior to being populated with information retrieved from the API

I am currently attempting to retrieve data from an API using Vuex.

Below is the action function in the Vuex store:

async getEpisodeFromApi({ commit }, id) {
      const data = {
        id
      };

      return await axios.get(Api.getUrl(data)).then((response) => {
        console.log("response.dat0dfgsdfa", response.data);
        commit("setEpisode", response.data);
      });
    }

This is the Api class that returns the link string:

class Api {
  getUrl(data) {
    return "https://www.breakingbadapi.com/api/episodes/" + data.id;
  }
}

export default new Api();

Here is how I attempted to interact with the retrieved data.

 async beforeCreate() {
    await this.$store.dispatch(
      "getEpisodeFromApi",
      this.$route.params.episode_id
    );
  },
  async mounted() {
    const episode = this.$store.state.episode;
    episode.characters.forEach((name) => {
      this.charactersInEpisode.push(
        this.$store.characters.find((character) => character.name === name)[0]
      );
    });
}

However, the Vuex store fills its state slower than the mounted hooks begin to work. This results in the `episode` variable being empty and `episode.characters` being undefined.

episode.characters being undefined can be seen here

Is there a way to expedite the process of filling the state in the store and retrieving the data faster than when the mounted hook runs the code?

javascript vue.js vuex

Answer 1

Answer №1

One way to optimize your code is by transforming the beforeCreated hook into a method. Here's how you can do it:

methods: {
  async fetchData() {
    await this.$store.dispatch(
      "fetchEpisodeFromApi",
      this.$route.params.episode_id
    );
  },
}

Then, within the mounted hook, you can simply wait for the data to be fetched:

async mounted() {
  await this.fetchData();
  const episode = this.$store.state.episode;
  episode.characters.forEach((name) => {
    this.charactersInEpisode.push(
      this.$store.characters.find((character) => character.name === name)[0]
    );
  });
}

Answer 2

One way to optimize your code is by transforming the beforeCreated hook into a method. Here's how you can do it:

methods: {
  async fetchData() {
    await this.$store.dispatch(
      "fetchEpisodeFromApi",
      this.$route.params.episode_id
    );
  },
}

Then, within the mounted hook, you can simply wait for the data to be fetched:

async mounted() {
  await this.fetchData();
  const episode = this.$store.state.episode;
  episode.characters.forEach((name) => {
    this.charactersInEpisode.push(
      this.$store.characters.find((character) => character.name === name)[0]
    );
  });
}

Answer 3

Answer №2

This code snippet demonstrates a computed property that retrieves characters in an episode. The property updates dynamically as the state is populated with data fetched from an API:

computed: {
    charactersInEpisode(){
        const episode = this.$store.state.episode;
        if (!episode) return []
        return episode.characters.map((name) => {
           return this.$store.state.characters.find((character) => character.name === name)[0]
        });
    }
}

Answer 4

This code snippet demonstrates a computed property that retrieves characters in an episode. The property updates dynamically as the state is populated with data fetched from an API:

computed: {
    charactersInEpisode(){
        const episode = this.$store.state.episode;
        if (!episode) return []
        return episode.characters.map((name) => {
           return this.$store.state.characters.find((character) => character.name === name)[0]
        });
    }
}

Answer 5

Answer №3

<!DOCTYPE html>
<html>
  <head>
    <link
      href="https://fonts.googleapis.com/css?family=Roboto:100,300,400,500,700,900|Material+Icons"
      rel="stylesheet"
    />
    <link href="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="99efecfcedf0ffe0d9a8b7e1">[email protected]</a>/dist/vuetify.min.css" rel="stylesheet" />
    <meta
      name="viewport"
      content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no, minimal-ui"
    />
  </head>
  <body>
    <div id="app">
      <v-app>
        <v-content>
          <v-container>
            <h2 class="red pa-2 primary white--text">Only Limited resolved questions</h2>
            <section v-for="(item, index) in questions" :key="index">
              <li>{{index}}.- {{item }}</li>
            </section>

            <section>
              <h3>Response question 1</h3>
              <blockquote class="pa-3 secondary white--text">
                This can be done from any lifecycle hook, or a method. For the example, beforeCreate is used.
              </blockquote>
              <pre>
                    {{ $store.state.episode }}
              </pre>
            </section>

            <section>
              <h3>Response question 2</h3>
              <blockquote class="pa-3 secondary white--text">This via getter and computed property</blockquote>
              <div v-for="(item, i) in charactersInEpisode" :key="i">{{ item }}</div>
            </section>
          </v-container>
        </v-content>
      </v-app>
    </div>

    <script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="b8cecdddf88a968e96898c">[email protected]</a>/dist/vue.js"></script>
    <script src="https://unpkg.com/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="a5d3d0c0dde5978b958b95">[email protected]</a>"></script>
    <script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="d9afacbcadb0bfa099e8f7a1">[email protected]</a>/dist/vuetify.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/axios/dist/axios.min.js"></script>

    <script>
     [ Custom script excluded for brevity ]
    </script>
  </body>
</html>

I focus solely on solving the specified problem (resolved questions), omitting other irrelevant code due to undefined variables not provided in the context.

Response to question 1: How can I populate store state?

This task can be accomplished using any lifecycle hook or method. In this case, beforeCreate is utilized as an example.

 async beforeCreate() {
      const episode_id = 1; // TODO: Use ID for simplicity initially, then consider utilizing/adjusting params: this.$route.params.episode_id
      await this.$store.dispatch("getEpisodeFromApi", episode_id);
    },

Response to question 2: Is it possible to retrieve data from the store faster than the mounted hook execution?

In the Nuxt framework (built on Vue), this can be achieved through asyncData, which fetches data prior to rendering. With just Vue, control can be attained through getters and computed properties, among other methods; I propose using the latter to execute code efficiently.

// store/index.js
  getters: {
      charactersInEpisode: (state) => {
        console.log("EXE GETTER", state);
        if (state.episode) {
          return state.episode.characters;
        } else {
          return [];
        }
      },
    },

// Component.vue
 computed: {
      ...Vuex.mapGetters(["charactersInEpisode"]),
    },

NOTE:

 setEpisode(state, payload) {
        state.episode = payload[0]; // POTENTIAL ENHANCEMENT FROM BACKEND, SENDING OBJECT {} (CURRENTLY AN ARRAY [])
      },

You can implement the solution and observe the reactivity. Hopefully, this proves beneficial.

Answer 6

<!DOCTYPE html>
<html>
  <head>
    <link
      href="https://fonts.googleapis.com/css?family=Roboto:100,300,400,500,700,900|Material+Icons"
      rel="stylesheet"
    />
    <link href="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="99efecfcedf0ffe0d9a8b7e1">[email protected]</a>/dist/vuetify.min.css" rel="stylesheet" />
    <meta
      name="viewport"
      content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no, minimal-ui"
    />
  </head>
  <body>
    <div id="app">
      <v-app>
        <v-content>
          <v-container>
            <h2 class="red pa-2 primary white--text">Only Limited resolved questions</h2>
            <section v-for="(item, index) in questions" :key="index">
              <li>{{index}}.- {{item }}</li>
            </section>

            <section>
              <h3>Response question 1</h3>
              <blockquote class="pa-3 secondary white--text">
                This can be done from any lifecycle hook, or a method. For the example, beforeCreate is used.
              </blockquote>
              <pre>
                    {{ $store.state.episode }}
              </pre>
            </section>

            <section>
              <h3>Response question 2</h3>
              <blockquote class="pa-3 secondary white--text">This via getter and computed property</blockquote>
              <div v-for="(item, i) in charactersInEpisode" :key="i">{{ item }}</div>
            </section>
          </v-container>
        </v-content>
      </v-app>
    </div>

    <script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="b8cecdddf88a968e96898c">[email protected]</a>/dist/vue.js"></script>
    <script src="https://unpkg.com/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="a5d3d0c0dde5978b958b95">[email protected]</a>"></script>
    <script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="d9afacbcadb0bfa099e8f7a1">[email protected]</a>/dist/vuetify.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/axios/dist/axios.min.js"></script>

    <script>
     [ Custom script excluded for brevity ]
    </script>
  </body>
</html>

I focus solely on solving the specified problem (resolved questions), omitting other irrelevant code due to undefined variables not provided in the context.

Response to question 1: How can I populate store state?

This task can be accomplished using any lifecycle hook or method. In this case, beforeCreate is utilized as an example.

 async beforeCreate() {
      const episode_id = 1; // TODO: Use ID for simplicity initially, then consider utilizing/adjusting params: this.$route.params.episode_id
      await this.$store.dispatch("getEpisodeFromApi", episode_id);
    },

Response to question 2: Is it possible to retrieve data from the store faster than the mounted hook execution?

In the Nuxt framework (built on Vue), this can be achieved through asyncData, which fetches data prior to rendering. With just Vue, control can be attained through getters and computed properties, among other methods; I propose using the latter to execute code efficiently.

// store/index.js
  getters: {
      charactersInEpisode: (state) => {
        console.log("EXE GETTER", state);
        if (state.episode) {
          return state.episode.characters;
        } else {
          return [];
        }
      },
    },

// Component.vue
 computed: {
      ...Vuex.mapGetters(["charactersInEpisode"]),
    },

NOTE:

 setEpisode(state, payload) {
        state.episode = payload[0]; // POTENTIAL ENHANCEMENT FROM BACKEND, SENDING OBJECT {} (CURRENTLY AN ARRAY [])
      },

You can implement the solution and observe the reactivity. Hopefully, this proves beneficial.

The Vuex store variable is being accessed prior to being populated with information retrieved from the API

Answer №1

Answer №2

Answer №3

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