Dynamically render checkboxes and handle change events: React+Typescript

Question

I am creating dynamic checboxes based on an array of objects but I am unable to set change handlers for the same . I am using semantic-ui-react Checkboxes. How do I handle change events for the corresponding change checkboxes.

Also There is a submit button , I need to get items that are checked .Can someone help me with this too

Help would be appreciated

Checkbox render code


    let arr = [  {key: "Pending", text: "Pending", checked: false}
         {key: "Approved", text: "Approved", checked: false}
         {key: "Cancelled", text: "Cancelled", checked: false}
    ];

    this.state ={ optionsArr: [] }

    {this.state.arr.map((item: any, i: number) => (
                      <div className="menu-item" key={i}>
                        <Checkbox
                          name={item.text}
                          onChange={this.handleItemClick}
                          checked={item.checked}
                          label={item.text}
                        />
                      </div>
      ))}

Change Handler

     handleItemClick = (event: React.FormEvent<HTMLInputElement>, data: any) => {
        const i = this.state.optionsArr.findIndex(
          (item: any) => item.text === data.name
        );
        const optionsArr = this.state.optionsArr.map((prevState: any, si: any) =>
          si === i ? !prevState : prevState
        );
        this.setState({ optionsArr });
      };

The first time you loop through the optionsArr, you use item.text on each item. The second time you loop through, if si === i you try to return !item. I'm not sure that makes sense, think you want to return {text: prevState.text, checked: !prevState.checked} — dbramwell
– dbramwell, Commented Jun 27, 2019 at 12:32

dbramwell · Accepted Answer · 2019-06-27 12:37:38Z

2

Think you are returning the wrong thing when trying to update the state of the options array.

prevState is an object, like {key: 'string', text: 'string', checked: boolean}, so doing !prevState doesn't make sense. Try:

     handleItemClick = (event: React.FormEvent<HTMLInputElement>, data: any) => {
        const i = this.state.optionsArr.findIndex(
          (item: any) => item.text === data.name
        );
        const optionsArr = this.state.optionsArr.map((prevState: any, si: any) =>
          si === i ? {...prevState, checked: !prevstate.checked} : prevState
        );
        this.setState({ optionsArr });
      };

You can get the checked items by using filter:


this.state.optionsArr.filter((item: any) => item.checked)

edited Jun 27, 2019 at 12:37

answered Jun 27, 2019 at 12:35

dbramwell

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4 Comments

dbramwell Over a year ago

Use filter. Updated my answer

dbramwell Over a year ago

store the original state in the state object also. Then you can call this.setState({optionsArr: this.state.original})

joy08 Over a year ago

That would give me all checkoxes unchecked as I am setting it to false in the begining. I want the previous state

dbramwell Over a year ago

What have you tried? I'm sure you can come up with something to store the previous state...

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