Component (React4j core binding)

java.lang.Object
- react4j.Component

public abstract class Component
extends java.lang.Object

The base java class that mirrors the react component.

Constructor Summary

Constructors
Constructor and Description

Component()

Constructors
Constructor and Description
`Component()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`componentDidCatch(elemental2.core.JsError error, ReactErrorInfo info)` The componentDidCatch() method works like a JavaScript catch {} block, but for components.
`protected void`	`componentDidMount()` This method is invoked after a component is attached to the DOM.
`protected void`	`componentDidUpdate()` This method is invoked immediately after updating occurs.
`protected void`	`componentWillUnmount()` This method is invoked immediately before a component is unmounted and destroyed.
`protected java.lang.String`	`getKey()` Return the key associated with the component if any.
`protected void`	`performComponentWillUnmount()` Wrapper method that delegates to the `componentWillUnmount()` method.
`protected void`	`performPostConstruct()` Wrapper method that delegates to the `postConstruct()` method.
`protected ReactNode`	`performRender()` Wrapper method that delegates to the `render()` method.
`protected void`	`populateDebugData(jsinterop.base.JsPropertyMap<java.lang.Object> state)` Populate the state parameter with any data that is useful when debugging the component.
`protected void`	`postConstruct()` This method is invoked after the component is constructed and bound to a native react component.
`protected jsinterop.base.JsPropertyMap<java.lang.Object>`	`props()` Return the component props from the native component.
`protected abstract ReactNode`	`render()` Render the component.
`protected boolean`	`reportPropChanges(jsinterop.base.JsPropertyMap<java.lang.Object> props, jsinterop.base.JsPropertyMap<java.lang.Object> nextProps, boolean inComponentDidUpdate)` Detect and report changes in props that are `Prop.observable()`.
`protected void`	`scheduleRender()` Schedule this component for re-rendering.
`protected boolean`	`shouldReportPropChanges(boolean inComponentDidUpdate)` Helper method invoked by `reportPropChanges(JsPropertyMap, JsPropertyMap, boolean)` method generated by the annotation processor.
`protected boolean`	`shouldUpdateOnPropChanges(jsinterop.base.JsPropertyMap<java.lang.Object> nextProps)` Detect changes in props that that do not require specific actions on change.
`protected jsinterop.base.JsPropertyMap<java.lang.Object>`	`state()` Return the component state from the native component.
`protected void`	`validatePropValues(jsinterop.base.JsPropertyMap<java.lang.Object> props)` Perform validation on props supplied to the component.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Component
```
public Component()
```
- Method Detail
  - state
```
protected final jsinterop.base.JsPropertyMap<java.lang.Object> state()
```
    Return the component state from the native component. This may be null if initial state was never set.
    
    Returns:
    
    the component state.
  - props
```
protected final jsinterop.base.JsPropertyMap<java.lang.Object> props()
```
    Return the component props from the native component. This may be null if no props were supplied.
    
    Returns:
    
    the component state.
  - getKey
```
@Nullable
protected final java.lang.String getKey()
```
    Return the key associated with the component if any. The key is used by the react reconcilliation process as a means to identify components so that they can be moved rather than recreated or reconfigured. Typically, it should not be used by the component itself except for generating keys of sub-components. This value may not be specified in which case null will be returned.
    
    Returns:
    
    the key if specified.
  - scheduleRender
```
protected final void scheduleRender()
```
    Schedule this component for re-rendering. The component re-renders when props change but calling this method is another way to schedule the component to be re-rendered. When this method is called the shouldComponentUpdate(JsPropertyMap) lifecycle method will be skipped. Calling this method is equivalent to calling forceUpdate() on the native react component. See the React Component documentation for more details.
  - render
```
@Nullable
protected abstract ReactNode render()
```
    Render the component. See the React Component documentation for more details.
    
    Returns:
    
    the result of rendering.
  - performRender
```
@Nullable
protected ReactNode performRender()
```
    Wrapper method that delegates to the render() method. This method exists to give middleware a mechanism to hook into component lifecycle step.
    
    Returns:
    
    the result of rendering.
  - performPostConstruct
```
protected void performPostConstruct()
```
    Wrapper method that delegates to the postConstruct() method. This method exists to give middleware a mechanism to hook into component lifecycle step.
  - postConstruct
```
protected void postConstruct()
```
    This method is invoked after the component is constructed and bound to a native react component. This is a good place to perform initialization. It is called before render(), therefore setting state in this method will not trigger a re-rendering. This replaces the componentWillMount lifecycle method from react as well as the code that appears in constructors in native React ES6 components.
  - componentDidMount
```
protected void componentDidMount()
```
    This method is invoked after a component is attached to the DOM. Initialization that requires DOM nodes should go here. Setting state in this method will trigger a re-rendering. See the React Component documentation for more details.
  - componentDidUpdate
```
protected void componentDidUpdate()
```
    This method is invoked immediately after updating occurs. If you need to interact with the DOM after the component has been updated. See the React Component documentation for more details.
  - componentWillUnmount
```
protected void componentWillUnmount()
```
    This method is invoked immediately before a component is unmounted and destroyed. Perform any necessary cleanup in this method, such as invalidating timers, canceling network requests, or cleaning up any DOM elements that were created in componentDidMount() See the React Component documentation for more details.
  - performComponentWillUnmount
```
protected void performComponentWillUnmount()
```
    Wrapper method that delegates to the componentWillUnmount() method. This method exists to give middleware a mechanism to hook into component lifecycle step.
  - componentDidCatch
```
protected void componentDidCatch(@Nonnull
                                 elemental2.core.JsError error,
                                 @Nonnull
                                 ReactErrorInfo info)
```
    The componentDidCatch() method works like a JavaScript catch {} block, but for components. Only class components can be error boundaries. In practice, most of the time you’ll want to declare an error boundary component once and use it throughout your application.
    Note that error boundaries only catch errors in the components below them in the tree. An error boundary can’t catch an error within itself. If an error boundary fails trying to render the error message, the error will propagate to the closest error boundary above it. This, too, is similar to how catch {} block works in JavaScript.
    
    Parameters:
    
    error - the error that has been thrown.
    
    info - information about component stack during thrown error.
  - reportPropChanges
```
protected boolean reportPropChanges(@Nonnull
                                    jsinterop.base.JsPropertyMap<java.lang.Object> props,
                                    @Nonnull
                                    jsinterop.base.JsPropertyMap<java.lang.Object> nextProps,
                                    boolean inComponentDidUpdate)
```
    Detect and report changes in props that are Prop.observable(). This method is a template method that may be overridden by subclasses generated by the annotation processor based on configuration of props.
    This method can be invoked from either the shouldComponentUpdate(JsPropertyMap) method or the componentDidUpdate() method. If the method is not invoked from the shouldComponentUpdate(JsPropertyMap) method first due to a scheduleRender() call then the call from componentDidUpdate() will report any changes to the observable props otherwise this will only occur in the invocation of the method from the shouldComponentUpdate(JsPropertyMap) method. This means that the props are marked as Prop.observable() and are used by a @Computed method from within the render call will only be reported as being changed once, normally before the render call. Thus the computed will be marked as potentially stale and recomputed if used in the render. Otherwise the computed will be marked as potentially stale after the render which could potentially trigger a re-render of the component.
    
    Parameters:
    
    props - the old properties of the component.
    
    nextProps - the new properties of the component.
    
    inComponentDidUpdate - true if this is being invoked from componentDidUpdate(), false if this is being invoked from shouldComponentUpdate(JsPropertyMap)
    
    Returns:
    
    true if a prop was marked with Prop.shouldUpdateOnChange() and has changed.
  - shouldReportPropChanges
```
protected final boolean shouldReportPropChanges(boolean inComponentDidUpdate)
```
    Helper method invoked by reportPropChanges(JsPropertyMap, JsPropertyMap, boolean) method generated by the annotation processor. This will return true if the changes should be reported.
    
    Parameters:
    
    inComponentDidUpdate - true if this is being invoked from componentDidUpdate(), false if this is being invoked from shouldComponentUpdate(JsPropertyMap)
    
    Returns:
    
    true if changes to observable props should be reported.
  - shouldUpdateOnPropChanges
```
protected boolean shouldUpdateOnPropChanges(@Nonnull
                                            jsinterop.base.JsPropertyMap<java.lang.Object> nextProps)
```
    Detect changes in props that that do not require specific actions on change. This method may be overridden by the annotation processor. The method will return true if a prop has been updated and the prop has not set Prop.shouldUpdateOnChange() to false. Otherwise this method will return false.
    
    Parameters:
    
    nextProps - the new properties of the component.
    
    Returns:
    
    true if the component should be updated.
  - validatePropValues
```
protected void validatePropValues(@Nonnull
                                  jsinterop.base.JsPropertyMap<java.lang.Object> props)
```
    Perform validation on props supplied to the component.
    
    Parameters:
    
    props - the props of the component.
  - populateDebugData
```
protected void populateDebugData(@Nonnull
                                 jsinterop.base.JsPropertyMap<java.lang.Object> state)
```
    Populate the state parameter with any data that is useful when debugging the component.
    
    Parameters:
    
    state - the property map to populate with debug data.

Class Component

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Component

Method Detail

state

props

getKey

scheduleRender

render

performRender

performPostConstruct

postConstruct

componentDidMount

componentDidUpdate

componentWillUnmount

performComponentWillUnmount

componentDidCatch

reportPropChanges

shouldReportPropChanges

shouldUpdateOnPropChanges

validatePropValues

populateDebugData