Passing-Data-in-React

A demo app to understand flow of data in react.

Introduction

React has one way of data flow, but sometimes it needs to be able to move from child to parent, parent to child or among children components.

Program structure

• Index
  • ProductList
    • InputBrand
    • Product
    • Total

Types of flow

Parent to Child

If parent have data then it can pass it down to its children via props.

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and in the child, those passed props can be accessed by

this.props.passedDownIdentifier

Props are immutable in child components.

Child to Parent

If child have data which parent needs to have access to then it is done via callback

1. Constuct the method in the parent with the parameters which you will recieve from the child.

callbackMethodInParent = (dataFromChild) => {
  // foo bar
};

2. Pass the constructed callback method to the child as props.

<ChildComponent callbackMethodInParent = {this.callbackMethodInParent} />

3. In the child call the callback with the data you recieved.

this.props.callbackMethodInParent(newData);

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Page status

https://updown.io/suC9