streamlit-component-lib-react-hooks/dist/cjs/useNullableRenderData.js

An npm package that provides support code for creating [Streamlit Components](https://docs.streamlit.io/en/stable/streamlit_components.html) with React and React Hooks.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.useNullableRenderData = void 0;
const react_1 = require("react");
const streamlit_component_lib_1 = require("streamlit-component-lib");
/**
 * Returns `RenderData` received from Streamlit after the first render event received.
 */
const useNullableRenderData = () => {
    const [renderData, setRenderData] = (0, react_1.useState)();
    (0, react_1.useEffect)(() => {
        const onRenderEvent = (event) => {
            const renderEvent = event;
            setRenderData(renderEvent.detail);
        };
        // Set up event listeners, and signal to Streamlit that we're ready.
        // We won't render the component until we receive the first RENDER_EVENT.
        streamlit_component_lib_1.Streamlit.events.addEventListener(streamlit_component_lib_1.Streamlit.RENDER_EVENT, onRenderEvent);
        streamlit_component_lib_1.Streamlit.setComponentReady();
        const cleanup = () => {
            streamlit_component_lib_1.Streamlit.events.removeEventListener(streamlit_component_lib_1.Streamlit.RENDER_EVENT, onRenderEvent);
        };
        return cleanup;
    }, []);
    return renderData;
};
exports.useNullableRenderData = useNullableRenderData;