React : Cannot set property ‘animation’ of undefined

I have a list in React where I’m using .map to render a loop from an array of elements.

The radio inputs are working perfectly, everyone is independent of the others, but I can’t do the same for Select.

The Select area is changing in every field, I want it to change to it specified field like I did for the options.

I tried to re-use the same handleChange that I used in the radios for it and instead I had this error.

Cannot set property 'animation' of undefined

In this line

newAnimations[indexurl].animation = name;

How do I manage to separate the selects ? Note: This code is working fine, but it’s updating the value on every field.

  const onChange = (animations) => {
    setAnimations(animations);
    console.log(`Animation selected:`, animations);
  };

Code : https://codesandbox.io/s/dank-violet-jibzh?file=/src/App.js:1065-1194

import React, { useState } from "react";
import Select from "react-select";

export default () => {
  const animationsList = [
    { value: "animation0", label: "Dance" },
    { value: "animation1", label: "Flip" },
    { value: "animation2", label: "Salsa" }
  ];

  const reactList = [
    {
      id: "14444",
      selected: "layout3",
      animation: "animation1"
    },
    {
      id: "24444",
      selected: "layout3",
      animation: "animation2"
    },
    {
      id: "34444",
      selected: "layout3",
      animation: "animation1"
    }
  ];

  const [links, setLinks] = useState(reactList);
  const [animations, setAnimations] = useState(animationsList[0]);

  const handleChangeSelectedReact = (indexurl, layout) => {
    const cloneLinks = [...links];
    cloneLinks[indexurl].selected = layout;
    setLinks(cloneLinks);
    console.log(cloneLinks);
  };

  /* const onChange = (animations) => {
    setAnimations(animations);
    console.log(`Animation selected:`, animations);
  };*/

  const onChange = (indexurl, name) => {
    const newAnimations = [...links];
    newAnimations[indexurl].animation = name;
    setAnimations(newAnimations);
    console.log(newAnimations);
  };

  return (
    <div>
      <ul>
        <div>
          {links.map((url, indexurl) => (
            <li key={url.id}>
              <div>
                <Select
                  options={animationsList}
                  onChange={onChange}
                  value={animations}
                />
                <p />{" "}
                <input
                  type="radio"
                  id={url.id}
                  name={url.id}
                  value="layout1"
                  checked={url.selected === "layout1"}
                  onChange={() =>
                    handleChangeSelectedReact(indexurl, "layout1")
                  }
                />
                <label for="huey">Option 1</label>
              </div>
              <div>
                <input
                  type="radio"
                  id={url.id}
                  name={url.id}
                  value="layout2"
                  checked={url.selected === "layout2"}
                  onChange={() =>
                    handleChangeSelectedReact(indexurl, "layout2")
                  }
                />
                <label for="dewey">Option 2</label>
              </div>
              <div>
                <input
                  type="radio"
                  id={url.id}
                  name={url.id}
                  value="layout3"
                  checked={url.selected === "layout3"}
                  onChange={() =>
                    handleChangeSelectedReact(indexurl, "layout3")
                  }
                />
                <label for="louie">Option 3</label>
              </div>
              <br />
            </li>
          ))}
        </div>
      </ul>
    </div>
  );
};

Answer

Multiple Selects share the same state, resulting in updates the value on every field. So we need to wrap Select into components and maintain their own state independently：

function SelectItem({ list }) {
  const [value, setValue] = React.useState(list[0]);
  const onChange = (newValue) => {
    setValue(newValue);
  };

  return <Select options={list} onChange={onChange} value={value} />;
}

...
...
  return (
    <div>
      {links.map((url, indexurl) => (
           
         <SelectItem list={animationsList} />
      
       ))}
    </div>
  );
...
...

Update

Modify the links when select is selected:

function SelectItem(props) {
  const [value, setValue] = React.useState(props.list[0]);

  return (
    <Select
      options={props.list}
      onChange={(newValue) => {
        setValue(newValue);
        props.onChange(newValue.value);
      }}
      value={value}
    />
  );
}

...
...
  const onChange = (index, animation) => {
    const cloneLinks = [...links];
    cloneLinks[index].animation = animation;
    setLinks(cloneLinks);
    console.log(cloneLinks);
  };

  return (
    <div>
      {links.map((url, indexurl) => (
           
          <SelectItem
             onChange={(animation) => onChange(indexurl, animation)}
             list={animationsList}
          />
      
       ))}
    </div>
  );
...
...

Full code: https://codesandbox.io/s/happy-cloud-m6z99?file=/src/App.js:77-298

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Answer