nostr-web-components/lib/utils.js

collection of web components that provide quick access to basic nostr things

function debounce(fn, wait = 100) {
  let timeoutId;
  let timestamp;
  let storedArguments;
  function later() {
    const last = Date.now() - timestamp;
    if (last < wait && last >= 0) {
      timeoutId = setTimeout(later, wait - last);
    } else {
      timeoutId = void 0;
      fn(...storedArguments);
    }
  }
  return function(...args) {
    timestamp = Date.now();
    storedArguments = args;
    if (!timeoutId) {
      timeoutId = setTimeout(later, wait);
    }
  };
}
function nostrLink(code) {
  let res = window.nwc?.nostrLink?.(code);
  if (res)
    return res;
  return "https://njump.me/" + code;
}
function relayLink(url) {
  let res = window.nwc?.relayLink?.(url);
  if (res)
    return res;
  return "https://njump.me/r/" + encodeURIComponent(url);
}
const transparentPixel = "data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==";
function handleImageError(ev) {
  const el = ev.target;
  console.warn("error loading image", ev);
  if (el.src !== transparentPixel) {
    el.src = transparentPixel;
  }
}
function splitComma(value) {
  return value ? value.split(" ").map((v) => v.trim()).filter((v) => v.length) : [];
}
function shorten(nip19code) {
  let idx = nip19code.indexOf("1");
  return nip19code.substring(0, idx + 3) + "\u2026" + nip19code.substring(nip19code.length - 5);
}
function shortenURL(url) {
  if (url.length <= 30)
    return url;
  try {
    let u = new URL(url);
    if (url.length <= 40) {
      return `${u.host}${u.pathname}${u.search.length ? "?" : ""}${u.search}`;
    }
    if (url.length <= 50 && u.pathname.length < 20) {
      return `${u.host}${u.pathname}`;
    }
    let pathname = u.pathname;
    let parts = u.pathname.split("/");
    let lastPart = parts[parts.length - 1];
    if (lastPart.length > 10) {
      lastPart = `\u2026${lastPart.substring(lastPart.length - 6)}`;
    }
    if (parts.length > 2) {
      pathname = `/\u2026/${lastPart}`;
    } else {
      pathname = `/${lastPart}`;
    }
    return `${u.host}${pathname}`;
  } catch (_err) {
    return url;
  }
}
export {
  debounce,
  handleImageError,
  nostrLink,
  relayLink,
  shorten,
  shortenURL,
  splitComma,
  transparentPixel
};