CODEWITHSUNDEEP
javascriptjqueryreactjs
Sander Bakker
Sander Bakker

Reputation: 621

onChange event select in ReactJs

I'm trying to get the value of an option inside my select in React.js but somehow e.value is always undefined.

This is the code:

<Col md={4} className="col-padding-left">
                            <Input onChange={this.filterProducts} type="select" name="select" id="exampleSelect">
                                <option name='default'>Default</option>
                                <option name='price' value='desc'>Price (High-Low)</option>
                                <option name='price' value='asc'>Price (Low-High)</option>
                                <option name='addedAt' value='desc'>Added At (First-Last)</option>
                                <option name='addedAt' value='asc' >Added At (Last-First)</option>
                                <option name='name' value='desc'>Name (A-Z)</option>
                                <option name='name' value='asc'>Name (Z-A)</option>
                            </Input>
                        </Col>

With the following function filterProducts: 

filterProducts(e){
            console.log(e.value); 
      }

Upvotes: 2

Views: 17923

Answers (5)

marcode_ely
marcode_ely

Reputation: 436

According to your request, it's my solution:

<Col md={4} className="col-padding-left">
                            <Input onChange={this.filterProducts} type="select" name="select" id="exampleSelect">
                                <option name='default'>Default</option>
                                <option name='price' value='desc'>Price (High-Low)</option>
                                <option name='price' value='asc'>Price (Low-High)</option>
                                <option name='addedAt' value='desc'>Added At (First-Last)</option>
                                <option name='addedAt' value='asc' >Added At (Last-First)</option>
                                <option name='name' value='desc'>Name (A-Z)</option>
                                <option name='name' value='asc'>Name (Z-A)</option>
                            </Input>
                        </Col>

The function for could be:

filterProducts(e){
    // e.target.id identified the unique element in DOM 
    // in example when 'exampleSelect' make a change (onChange) event
    if(e.target.id === 'exampleSelect'){  
            console.log("Value for exampleSelect: " + e.target.value);   
    }
    // if you have another html input select add here another 'if'
    // with a diferent id. ex.
    if(e.target.id === 'fruitSelect'){  
            console.log("Value for fruit: " + e.target.value);   
    }
    ...
}

¡Ey!, don't forget to bind the function, in the React constructor:

this.filterProducts = this.filterProducts.bind(this);

Upvotes: 0

Sagiv b.g
Sagiv b.g

Reputation: 31024

The event object doesn't hold a value property.
In order to access the value attribute of element you need to use event.target.value when target is the element that triggered this event.

Running example: 

class App extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      items: ['john', 'jane', 'greg']
    };
  }

  onSelect = e => {
    console.log(e.target.value);
  }

  render() {
    const{items} = this.state;
    return (
      <div>
        <select onChange={this.onSelect}>
        {
          items.map(item => {
            return (<option value={item}>{item}</option>)
          })
        }
        </select>
      </div>
    );
  }
}

ReactDOM.render(<App />, document.getElementById("root"));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="root"></div>

Upvotes: 1

Ken Ha
Ken Ha

Reputation: 127

Try this

<Col md={4} className="col-padding-left">
                        <Input onChange={this.filterProducts.bind(this)} type="select" name="select" id="exampleSelect">
                            <option name='default'>Default</option>
                            <option name='price' value='desc'>Price (High-Low)</option>
                            <option name='price' value='asc'>Price (Low-High)</option>
                            <option name='addedAt' value='desc'>Added At (First-Last)</option>
                            <option name='addedAt' value='asc' >Added At (Last-First)</option>
                            <option name='name' value='desc'>Name (A-Z)</option>
                            <option name='name' value='asc'>Name (Z-A)</option>
                        </Input>
                    </Col>


filterProducts = (e) => {
        console.log(e.target.value); 
  }

Upvotes: 1

Vitalii Saienko
Vitalii Saienko

Reputation: 27

First, check if you have e. If so, try e.target.value.

Upvotes: 0

Sven Tschui
Sven Tschui

Reputation: 1435

You need to use e.target.value

See this question: OnChange event using React JS for drop down

Upvotes: 0

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