Called immediately before mounting occurs, and before Component#render
.
Avoid introducing any side-effects or subscriptions in this method.
This method will not stop working in React 17.
Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps prevents this from being invoked.
Called when the component may be receiving new props. React may call this even if props have not changed, so be sure to compare new and existing props if you only want to handle changes.
Calling Component#setState
generally does not trigger this method.
This method will not stop working in React 17.
Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps prevents this from being invoked.
Called immediately before rendering when new props or state is received. Not called for the initial render.
Note: You cannot call Component#setState
here.
This method will not stop working in React 17.
Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps prevents this from being invoked.
Catches exceptions generated in descendant components. Unhandled exceptions will cause the entire component tree to unmount.
Called immediately after a compoment is mounted. Setting state here will trigger re-rendering.
Called immediately after updating occurs. Not called for the initial render.
The snapshot is only present if getSnapshotBeforeUpdate is present and returns non-null.
Called immediately before mounting occurs, and before Component#render
.
Avoid introducing any side-effects or subscriptions in this method.
Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps prevents this from being invoked.
Called when the component may be receiving new props. React may call this even if props have not changed, so be sure to compare new and existing props if you only want to handle changes.
Calling Component#setState
generally does not trigger this method.
Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps prevents this from being invoked.
Called immediately before a component is destroyed. Perform any necessary cleanup in this method, such as
cancelled network requests, or cleaning up any DOM elements created in componentDidMount
.
Called immediately before rendering when new props or state is received. Not called for the initial render.
Note: You cannot call Component#setState
here.
Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps prevents this from being invoked.
Returns the topmost region which contains the point [x, y]
, or undefined
if no such region can be found
X coordinate of the drop location
Y coordinate of the drop location
The region which contains [x, y]
Runs before React applies the result of render
to the document, and
returns an object to be given to componentDidUpdate. Useful for saving
things such as scroll position before render
causes changes to it.
Note: the presence of getSnapshotBeforeUpdate prevents any of the deprecated lifecycle events from running.
Callback invoked when an element has been dropped over a screen region.
ID of the component which has been dropped
X coordinate of the drop location
Y coordinate of the drop location
Renders the component.
Called to determine whether the change in props and state should trigger a re-render.
Component
always returns true.
PureComponent
implements a shallow comparison on props and state and returns true if any
props or states have changed.
If false is returned, Component#render
, componentWillUpdate
and componentDidUpdate
will not be called.
Generated using TypeDoc
DroppableScreen represents a preview screen and renders all regions contained within that screen and allows the user to drop elements onto it via drag and drop. A callback then returns the ID of the region that the component has been dropped on. The screen information is passed in through the
screenInfo
prop. The screen can render at an arbitray size, determined by * the propswidth
andheight
. Though both are optional, at least one of * them must be defined, otherwise the component does not render anything.This component also defines a callback
assignElementToRegion
, which is invoked whenever an element is dropped over a screen region. The callback receives the id of the component as well as the id of the region as params.An object containing data associated with a preview screen
The width of the rendered screen. Optional
The height of the rendered screen. Optional
Callback to assign a component dropped on screen to a region. Optional