MediaWiki:Gadget-main-spoiler-warning-screen.js

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/* Finds elements by a selector and executes a function for each element */
function findAndExecute(selector, callback) {
    const elements = document.querySelectorAll(selector);
    elements.forEach((element) => {
        try {
            callback(element);
        } catch (e) {
            console.error(`Error while initializing "${selector}"`, e);
        }
    });
}

/* Spoiler warning screen */
window.rgwiki_main_spoilerWarningScreenShown = false;
findAndExecute(".rgwiki-main-show-spoiler-warning-screen", () => {
    if (window.rgwiki_main_spoilerWarningScreenShown) {
        return;
    }

    let screen = document.createElement("div");
    screen.innerText = "Spoiler warning!";
    screen.classList.add("rgwiki-main-spoiler-warning-screen");
    document.body.appendChild(screen);

    window.rgwiki_main_spoilerWarningScreenShown = true;
});