@proca/widget/public/embed.js

Proca is an open-source campaign toolkit designed to empower activists and organisations in their digital advocacy efforts. It provides a flexible and customisable platform for creating and managing online petitions, email campaigns, and other forms of di

//https://mstdn.social/embed.js
// @ts-check

(function () {
  "use strict";

  /**
   * @param {() => void} loaded
   */
  var ready = function (loaded) {
    if (document.readyState === "complete") {
      loaded();
    } else {
      document.addEventListener("readystatechange", function () {
        if (document.readyState === "complete") {
          loaded();
        }
      });
    }
  };

  ready(function () {
    /** @type {Map<number, HTMLIFrameElement>} */
    var iframes = new Map();

    window.addEventListener("message", function (e) {
      var data = e.data || {};

      if (
        typeof data !== "object" ||
        data.type !== "setHeight" ||
        !iframes.has(data.id)
      ) {
        return;
      }

      var iframe = iframes.get(data.id);

      if ("source" in e && iframe.contentWindow !== e.source) {
        return;
      }

      iframe.height = data.height;
    });

    [].forEach.call(
      document.querySelectorAll("iframe.proca-embed"),
      function (iframe) {
        // select unique id for each iframe
        var id = 0,
          failCount = 0,
          idBuffer = new Uint32Array(1);
        while (id === 0 || iframes.has(id)) {
          id = crypto.getRandomValues(idBuffer)[0];
          failCount++;
          if (failCount > 100) {
            // give up and assign (easily guessable) unique number if getRandomValues is broken or no luck
            id = -(iframes.size + 1);
            break;
          }
        }

        iframes.set(id, iframe);

        iframe.scrolling = "no";
        iframe.style.overflow = "hidden";

        iframe.onload = function () {
          iframe.contentWindow.postMessage(
            {
              type: "setHeight",
              id: id,
            },
            "*"
          );
        };

        iframe.onload();
      }
    );
  });
})();