Conditionally add attributes to React components

I n React, its often required to add attributes conditionally. It is very easy in React. For certain attributes, React is intelligent enough to omit the attribute if the value you pass to it is not truthy. This is actually very useful, especially when adding many properties conditionally. In this article we will learn how we can add attributes in React component conditionally.

Prepare props to conditionally add attributes to react components

The below code will add the props dynamically in the component.

                            var inputProps = {
                                value: 'Hello',
                                onChange: this.handleChange
                              };
                              
                              if (condition){
                                inputProps.disabled = true;
                              }
                          

Use props to conditionally add attributes to react component::

This is how, we can use the props.

                            <SomeComponent
                            {...inputProps}
                            value="this is overridden by inputProps"
                            onChange={overridesInputProps}
                         />
                          

Another way to conditionally add attributes to react component:

                            var condition = true;
                            return (
                              <SomeComponent {...(condition ? {Key: "Value"} : {})} />
                              // Or
                              <SomeComponent Key={condition ? "Value" : undefined} />
                            );
                          

Depending on the condition, either {Key: "Value"} or {} will be returned. The spread operator will then spread the properties of the returned object to Button component. In the falsy case, since no properties exist on the returned object, nothing will be passed to the component.

The only small difference is that in the second example the inner component SomeComponent's props object will have a key bsStyle with a value of undefined.