How to update component based on container's state change
Multi tool use
Clash Royale CLAN TAG#URR8PPPHow to update component based on container's state change
I have a React container called UserContainer which renders a component called UserComponent.
UserContainer
UserComponent
The code looks approximately like this (I have removed the unnecessary bits):
// **** CONTAINER **** //
class UserContainer extends React.Component<ContainerProps, ContainerState> {
state = { firstName: "placeholder" };
async componentDidMount() {
const response = await this.props.callUserApi();
if (response.ok) {
const content: ContainerState = await response.json();
this.setState({ firstName: content.firstName });
}
}
private isChanged(componentState: ComponentState) {
return this.state.firstName === componentState.firstName;
}
async save(newValues: ComponentState) {
if (!this.isChanged(newValues)) {
console.log("No changes detected.");
return;
}
const response = await this.props.changeFirstName(newValues.firstName);
if (response.ok) {
const content: ContainerState = await response.json();
this.setState({ firstName: content.firstName });
}
}
render() {
return <UserComponent firstName={this.state.firstName} onSave={(newValues: ComponentState) => this.save(newValues)} />;
}
}
export default UserContainer;
// **** COMPONENT **** //
class UserComponent extends React.PureComponent<ComponentProps, ComponentState> {
constructor(props: ComponentProps) {
super(props);
this.state = { firstName: props.firstName }
}
render() {
return (
<div>
<input type="text" value={this.state.firstName} onChange={evt => this.setState({ firstName: evt.target.value})} />
<button type="button" onClick={() => this.props.onSave(this.state)}>Save</button>
</div>
);
}
}
export default UserComponent;
The problem is that this.state.firstName in the component is always "placeholder". Even after the container gets its values from the API, the state of the component is not changed (however, the props are changed). When adding console.log into the individual methods, the flow of individual steps is following:
this.state.firstName
state
props
console.log
As you can see, the component constructor is called just once, prior to the container receiving its data from the backend API. Is there a way to pass the updated container state into the component in order to display the real data?
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