Function processSetProps

dash/dash-renderer/src/observers/websocketObserver.ts:79–133

(payload: SetPropsPayload)

    // Helper to process a single set_props payload
    const processSetProps = (payload: SetPropsPayload) => {
        const {componentId, props: rawProps} = payload;
        const parsedId = parseComponentId(componentId);
        const state = store.getState();
        const componentPath = getPath(state.paths, parsedId);

        if (!componentPath) {
            console.warn(
                `SET_PROPS: Component ${componentId} not found in layout`
            );
            return;
        }

        // Get old component for Patch processing and path recomputation
        const oldComponent = path(componentPath, state.layout) as Record<
            string,
            unknown
        > | null;
        const oldProps = (oldComponent?.props || {}) as Record<string, unknown>;

        // Process props to handle Patch objects
        const processedProps = parsePatchProps(rawProps, oldProps);

        // Update the component props
        store.dispatch(
            updateProps({
                props: processedProps,
                itempath: componentPath,
                renderType: 'websocket'
            }) as any
        );

        // Notify observers
        store.dispatch(
            notifyObservers({id: parsedId, props: processedProps}) as any
        );

        // Recompute paths for any new child components
        if (oldComponent) {
            const updatedState = store.getState();
            store.dispatch(
                setPaths(
                    computePaths(
                        {
                            ...oldComponent,
                            props: {...oldProps, ...processedProps}
                        },
                        [...componentPath],
                        updatedState.paths,
                        updatedState.paths.events
                    )
                ) as any
            );
        }
    };

    // Handle single SET_PROPS message
    workerClient.onSetProps = processSetProps;