How can I trigger an event in Vue.js when a selection is made in a dropdown menu?

Question

How can I trigger an event in Vue.js when a selection is made in a dropdown menu?

Here is an illustration fiddle:

Initially, it shows the name "Carl"

If I choose Carol, Clara, etc., an event will be triggered and data will be logged to the console.

However, if I click on the dropdown and select "Carl" again, no event will be triggered, and nothing will be displayed in the console.

The event listener being used is @input:

<select v-model="selectedPerson" @input="myEvent()">

How can I ensure that an event is fired every time a selection is made, even if it's the same value?

Edit:

To clarify, when "Carl" is initially selected:

https://i.sstatic.net/qIqYU.png

and then the dropdown is opened:

https://i.sstatic.net/2qUbT.png

and Carl is selected once more, I would like an event to be triggered and information logged to the console. Currently, no event is triggered and nothing is printed to the console.

javascript vue.js

Answer 1

Answer №1

When you choose the default option of 1 in this select menu, clicking on "Carl" will not trigger any change. To capture the value of "Carl" when clicked, you need to utilize the "@change" event and include a placeholder in the select option.

new Vue({
    el: '#app',
    template: `
        <div>
            <select v-model="selectedPerson" @change="myEvent()">
                <option :value="null" disabled hidden>Select option</option>
                <option v-for="person in people" :value="person.key" :selected="person.key == selectedPerson">{{person.name}}</option>
            </select>
        </div>
    `,
    data: {
        people: [
            {key: 1, name: "Carl"},
            {key: 2, name: "Carol"},
            {key: 3, name: "Clara"},
            {key: 4, name: "John"},
            {key: 5, name: "Jacob"},
            {key: 6, name: "Mark"},
            {key: 7, name: "Steve"}
        ],
        selectedPerson: null
    },
    methods: {
    myEvent: function() {
    console.log(this.selectedPerson);
    }
    }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app"></div>

Answer 2

When you choose the default option of 1 in this select menu, clicking on "Carl" will not trigger any change. To capture the value of "Carl" when clicked, you need to utilize the "@change" event and include a placeholder in the select option.

new Vue({
    el: '#app',
    template: `
        <div>
            <select v-model="selectedPerson" @change="myEvent()">
                <option :value="null" disabled hidden>Select option</option>
                <option v-for="person in people" :value="person.key" :selected="person.key == selectedPerson">{{person.name}}</option>
            </select>
        </div>
    `,
    data: {
        people: [
            {key: 1, name: "Carl"},
            {key: 2, name: "Carol"},
            {key: 3, name: "Clara"},
            {key: 4, name: "John"},
            {key: 5, name: "Jacob"},
            {key: 6, name: "Mark"},
            {key: 7, name: "Steve"}
        ],
        selectedPerson: null
    },
    methods: {
    myEvent: function() {
    console.log(this.selectedPerson);
    }
    }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app"></div>

Answer 3

Answer №2

Quite a clever solution, I've implemented @click and utilized event.detail or event.which:

new Vue({
  el: '#app',
  template: `
        <div>
            <select v-model="selectedPerson" @input="myEvent($event)" @click="myEvent($event)">
                <option v-for="person in people" :value="person.key" :selected="person.key == selectedPerson">{{person.name}}</option>
            </select>
        </div>
    `,
  data: {
    people: [{
        key: 1,
        name: "Carl"
      },
      {
        key: 2,
        name: "Carol"
      },
      {
        key: 3,
        name: "Clara"
      },
      {
        key: 4,
        name: "John"
      },
      {
        key: 5,
        name: "Jacob"
      },
      {
        key: 6,
        name: "Mark"
      },
      {
        key: 7,
        name: "Steve"
      }
    ],
    selectedPerson: 1
  },
  methods: {
    myEvent: function(e) {
      if (e.detail == 0)//if (e.which == 0)
        console.log(e.type, this.selectedPerson);
    }
  }
});

body {
  margin: 20px;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

.as-console-wrapper {
  height: 39px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.0.3/vue.js"></script>
<div id="app"></div>

A more elegant approach using data:

new Vue({
  el: '#app',
  template: `
        <div>
            <select v-model="selectedPerson" @input="myEvent($event)" @click="myEvent($event)">
                <option v-for="person in people" :value="person.key" :selected="person.key == selectedPerson">{{person.name}}</option>
            </select>
        </div>
    `,
  data: {
    people: [{
        key: 1,
        name: "Carl"
      },
      {
        key: 2,
        name: "Carol"
      },
      {
        key: 3,
        name: "Clara"
      },
      {
        key: 4,
        name: "John"
      },
      {
        key: 5,
        name: "Jacob"
      },
      {
        key: 6,
        name: "Mark"
      },
      {
        key: 7,
        name: "Steve"
      }
    ],
    selectedPerson: 1,
    prev: 0,
    isChanged: false
  },
  methods: {
    myEvent: function(e) {
      if (e.type == "input" || (e.type == "click" && !this.isChanged && (this.prev == this.selectedPerson || this.prev == 0))) {
        this.isChanged = true;
        this.prev = 0;
      } else if (e.type == "click" && this.isChanged) {
        console.log(e.type, this.selectedPerson);
        this.prev = this.selectedPerson;
        this.isChanged = false;
      }
    }
  }
});

body {
  margin: 20px;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

.as-console-wrapper {
  height: 39px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.0.3/vue.js"></script>
<div id="app"></div>

Answer 4

Quite a clever solution, I've implemented @click and utilized event.detail or event.which:

new Vue({
  el: '#app',
  template: `
        <div>
            <select v-model="selectedPerson" @input="myEvent($event)" @click="myEvent($event)">
                <option v-for="person in people" :value="person.key" :selected="person.key == selectedPerson">{{person.name}}</option>
            </select>
        </div>
    `,
  data: {
    people: [{
        key: 1,
        name: "Carl"
      },
      {
        key: 2,
        name: "Carol"
      },
      {
        key: 3,
        name: "Clara"
      },
      {
        key: 4,
        name: "John"
      },
      {
        key: 5,
        name: "Jacob"
      },
      {
        key: 6,
        name: "Mark"
      },
      {
        key: 7,
        name: "Steve"
      }
    ],
    selectedPerson: 1
  },
  methods: {
    myEvent: function(e) {
      if (e.detail == 0)//if (e.which == 0)
        console.log(e.type, this.selectedPerson);
    }
  }
});

body {
  margin: 20px;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

.as-console-wrapper {
  height: 39px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.0.3/vue.js"></script>
<div id="app"></div>

A more elegant approach using data:

new Vue({
  el: '#app',
  template: `
        <div>
            <select v-model="selectedPerson" @input="myEvent($event)" @click="myEvent($event)">
                <option v-for="person in people" :value="person.key" :selected="person.key == selectedPerson">{{person.name}}</option>
            </select>
        </div>
    `,
  data: {
    people: [{
        key: 1,
        name: "Carl"
      },
      {
        key: 2,
        name: "Carol"
      },
      {
        key: 3,
        name: "Clara"
      },
      {
        key: 4,
        name: "John"
      },
      {
        key: 5,
        name: "Jacob"
      },
      {
        key: 6,
        name: "Mark"
      },
      {
        key: 7,
        name: "Steve"
      }
    ],
    selectedPerson: 1,
    prev: 0,
    isChanged: false
  },
  methods: {
    myEvent: function(e) {
      if (e.type == "input" || (e.type == "click" && !this.isChanged && (this.prev == this.selectedPerson || this.prev == 0))) {
        this.isChanged = true;
        this.prev = 0;
      } else if (e.type == "click" && this.isChanged) {
        console.log(e.type, this.selectedPerson);
        this.prev = this.selectedPerson;
        this.isChanged = false;
      }
    }
  }
});

body {
  margin: 20px;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

.as-console-wrapper {
  height: 39px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.0.3/vue.js"></script>
<div id="app"></div>

Answer 5

Answer №3

By selecting a different option in the dropdown menu, you can access the index of the people array and use it to retrieve a specific value like shown below:

    myFunction: function() {
    console.log(this.people[this.selectedPerson].name);
    }
   }

Answer 6

By selecting a different option in the dropdown menu, you can access the index of the people array and use it to retrieve a specific value like shown below:

    myFunction: function() {
    console.log(this.people[this.selectedPerson].name);
    }
   }

Answer 7

Answer №4

To work around this issue, one solution is to assign a value that is not already in use when the input field is focused. This will trigger the change event regardless of which option is selected.

<select 
    v-model="selectedPerson" 
    ref="s" 
    @focus="selectedPerson = 0" 
    @change="myEvent()"
>

Check out the example on this fiddle: https://jsfiddle.net/tne1wp3q/

However, this workaround is not perfect as the change event may be triggered multiple times with each click and if no options are selected, it could remain empty. Additional code is required to handle these scenarios.

Answer 8

To work around this issue, one solution is to assign a value that is not already in use when the input field is focused. This will trigger the change event regardless of which option is selected.

<select 
    v-model="selectedPerson" 
    ref="s" 
    @focus="selectedPerson = 0" 
    @change="myEvent()"
>

Check out the example on this fiddle: https://jsfiddle.net/tne1wp3q/

However, this workaround is not perfect as the change event may be triggered multiple times with each click and if no options are selected, it could remain empty. Additional code is required to handle these scenarios.

How can I trigger an event in Vue.js when a selection is made in a dropdown menu?

Answer №1

Answer №2

Answer №3

Answer №4

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