Using JavaScript libraries can become quite difficult to handle data sometimes. Be it jQuery, D3.js Underscore, Algolia Places, or any other library. REACT is a similar JavaScript library maintained by Facebook, which is used to build user interfaces. It uses reusable components, allowing you to reuse the code and update components easily. 

However, with only a one-way flow of data, REACT becomes a bit difficult when you want to see data moving from one component to another. As your React JS development company, this is where we will help you understand how data is passed from one component to another. 

Data is passed between three components which include, 

Passing of data from “PARENT” to “CHILD.” This involves the use of “PROPS” and STATE

Passing of data from “CHILD” to “PARENT.” This involves the use of “CALLBACK.”  

Passing of data from one “SIBLING” to another “SIBLING.” This can be achieved by three methods, which will be discussed later.

Passing of data from “PARENT” to “CHILD.”

The passing of data from “PARENT” to “CHILD” takes place, using “PROPS” or “STATE.” Therefore, before we discuss the transfer, we need to understand “PROPS” and State and its role in data transfer. 

PROP and STATE

“PROPS” and State allows us to pass data from one component to another in REACT. Using “PROPS,” we can pass on different “CALLBACK” functions and other data pieces. Moreover, the value of “PROPS” is immutable. 

Apart from this, we can add more than one prop to each component, and accessing them becomes quite easy. A state is limited only inside a “PARENT,” To access that data, we will require “PROPS.” On the other hand, STATE is an object of JavaScript which has mutable values in it. Therefore, “PROPS” is how the data will pass from a “PARENT” to the “CHILD” component. 

Passing Data from “PARENT” to child

Using REACT, you can only pass data down a family tree and not the other way around. This means that a “PARENT” can pass data using “PROPS” to a child, but “CHILDREN” cannot use “PROPS” to pass the data. Therefore, the data moves down the component hierarchy unless some different state managers are used. 

To pass “PROPS” down the family tree, you need to name the prop and then make it equal to some value. 

To understand better let us take an example, 

function Example1(){

return(<div> //passing xyz prop to first component

<First xyz =‘ABC/>

</div>)

}

Then,  

function First(props){

 return(<div> //using prop to pass down the hierarchy line

<p>This will appear{props.xyz}</p>

</div>  

In the above example, we are passing “XYZ,” a prop with a value equal to a string. While passing this prop, we gain access to the component “First.” Now to get access to the information of the prop, we used the statement, “PROPS”.xyz,” letting us have access to the prop like an argument to a function. 

Passing of data from “CHILD” to “PARENT.”

Passing data from “CHILD” to “PARENT” is not possible using “PROPS.” Therefore, we use another function called “CALLBACK” to pass data from a “CHILD” to its “PARENT.” 

“CALLBACK”

When you want to change a “PARENT” component state, you must use “CALLBACK.” You could say that with this, a “CHILD” component says “howdie pops” to its “PARENT” component. This comes extremely handy when you change your “CHILD” component and want to change the value in the “PARENT” component. So, when we are using “CALLBACK,” the “PARENT” component is also affected. 

Passing Data from “CHILD” to “PARENT”

To pass data from “CHILD” to “PARENT,” you need to follow the given steps, 

Create a “CALLBACK” function in the “PARENT” component, taking the value you need as your parameter.

Now, you can pass the “CALLBACK” function just like a prop to the “CHILD” component (The method is similar to passing “PROPS” from “PARENT” to “CHILD” mentioned above).

Now, using this.props[“CALLBACK”] present in the “CHILD” component, call your “CALLBACK” function, and now pass the data like an argument (in the argument saying [“CALLBACK”] use the name of your choice).

Passing data between sibling components

Passing of data between “PARENT” and “CHILD” can be performed using “PROPS,” data from “CHILD” to “PARENT” can be passed using “CALLBACK” functions, now how to pass data between siblings? Well, there are three methods to do this, 

First: Using a combination of methods used in the above two data transfers

Second: Using Redux 

Third: Using the Context API of REACT

Integrating the combination of methods explained above

This is the most basic of the methods to pass on data from one component to another. You need to use the “PARENT” component as an intermediary in this method. To do this, you will be required to pass data from a “CHILD,” say “Child1” to its “PARENT” component. This can be done by using the “CALLBACK” function. Now, you need to set this parameter called back as a state to the “PARENT” component and now pass it down the hierarchy line to another “CHILD” component, say “Child2” using “PROPS.” This way, siblings will share the data. 

However, this sounds simple but might not be efficient when working with complicated directory structures, as it might require a lot of coding. If the components are different from one another at many levels, it will become tough, and your data will be moving too much back and forth in the program. 

Using redux to manage and centralize application state

Redux is a JavaScript library that allows you to manage and centralize the State of the program. You can maintain the states of different “CHILD” components in a global store, and then you can access the data from that store

Using the context API of REACT 

Redux is now losing its edge as the context API of REACT allows you to transfer data without passing the variables to the subcomponents, which is often called prop-drilling. Passing down the parameters to the following functions as you move is the concept behind this method.

Conclusion

With the methods mentioned above, you have now understood how data is passed from different components in REACT. Passing data might seem tricky, but you will become a master of passing data in whichever component you like with these techniques. You can also hire React JS developers for your business and enhance your business.