espresso_frame/server/app/static/widget_dialog_whiteboard.js

// Whiteboard widget dialog: source URL (owner-gated, see
// api_widgets.py's api_widget_whiteboard_source), preview, and the file
// browser. Not a page-load script -- frame_layout.js fetches this
// widget's dialog HTML fragment, injects it into the shared <dialog>,
// points window.FRAME_API at this specific widget (/api/frames/{id}/
// widgets/{widget_id}), then calls initWhiteboardDialog().

// Rewrites #whiteboard-current-source in place instead of telling the
// user to reload -- the API always assigns a successful "set" to the
// caller (see api_widget_whiteboard_source), so after either action we
// already know exactly what the new state is without asking the server
// again.
function renderWhiteboardCurrentSource(url) {
  const container = document.getElementById('whiteboard-current-source');
  container.innerHTML = '';
  const p = document.createElement('p');
  p.className = 'sub';
  p.style.marginTop = '10px';
  if (url) {
    p.append('Currently showing ');
    const urlEl = document.createElement('strong');
    urlEl.textContent = url;
    p.append(urlEl, ' using your WebDAV account. ');
    const clearBtn = document.createElement('button');
    clearBtn.type = 'button';
    clearBtn.className = 'btn-inline secondary';
    clearBtn.id = 'whiteboard-source-clear';
    clearBtn.textContent = 'Clear';
    clearBtn.addEventListener('click', clearWhiteboardSource);
    p.append(clearBtn);
  } else {
    p.textContent = 'No whiteboard configured yet.';
  }
  container.append(p);

  const label = document.getElementById('whiteboard-source-form-label');
  if (label) {
    label.textContent = url ? 'Change to one of your own files' : 'Use one of your own files';
  }
}

async function clearWhiteboardSource() {
  try {
    const resp = await fetch(`${window.FRAME_API}/whiteboard-source`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ url: null }),
    });
    if (!resp.ok) throw new Error(await apiError(resp));
    showStatus(true, 'Cleared.');
    renderWhiteboardCurrentSource(null);
    const urlInput = document.getElementById('whiteboard-url-input');
    if (urlInput) urlInput.value = '';
    loadWhiteboardPreview(false);
  } catch (e) {
    showStatus(false, e.message);
  }
}

function loadWhiteboardPreview(force) {
  const forceParam = force ? '&force=1' : '';
  document.getElementById('whiteboard-preview').src = `${window.FRAME_API}/preview/whiteboard?_=${Date.now()}${forceParam}`;
}

function initWhiteboardDialog() {
  const whiteboardForm = document.getElementById('whiteboard-source-form');
  if (whiteboardForm) {
    whiteboardForm.addEventListener('submit', async (e) => {
      e.preventDefault();
      const url = document.getElementById('whiteboard-url-input').value.trim();
      if (!url) return;
      try {
        const resp = await fetch(`${window.FRAME_API}/whiteboard-source`, {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({ url }),
        });
        if (!resp.ok) throw new Error(await apiError(resp));
        showStatus(true, 'Saved.');
        renderWhiteboardCurrentSource(url);
        loadWhiteboardPreview(false);
      } catch (e) {
        showStatus(false, e.message);
      }
    });
  }

  const whiteboardClearBtn = document.getElementById('whiteboard-source-clear');
  if (whiteboardClearBtn) {
    whiteboardClearBtn.addEventListener('click', clearWhiteboardSource);
  }

  // Shows whatever's already cached (cheap, no refetch) on open; the
  // button is the one place that means "no really, go check now" --
  // bypasses the fetch throttle server-side (see api_widget_preview_
  // whiteboard's `force` param).
  document.getElementById('whiteboard-preview-refresh').addEventListener('click', () => loadWhiteboardPreview(true));
  loadWhiteboardPreview(false);
  initBorderFields();

  // --- file picker (Browse...) ---
  const browseToggle = document.getElementById('whiteboard-browse-toggle');
  if (browseToggle) {
    const browsePanel = document.getElementById('whiteboard-browser');
    const browseList = document.getElementById('whiteboard-browse-list');
    const browseCurrent = document.getElementById('whiteboard-browse-current');
    const browseUp = document.getElementById('whiteboard-browse-up');
    const browseError = document.getElementById('whiteboard-browse-error');
    const urlInput = document.getElementById('whiteboard-url-input');
    let opened = false;

    async function browseTo(url) {
      browseError.style.display = 'none';
      browseList.innerHTML = '<li class="sub">Loading...</li>';
      try {
        const qs = url ? `?url=${encodeURIComponent(url)}` : '';
        const resp = await fetch(`${window.FRAME_API}/whiteboard-browse${qs}`);
        if (!resp.ok) throw new Error(await apiError(resp));
        const data = await resp.json();
        browseCurrent.textContent = data.current_url;
        browseUp.disabled = !data.parent_url;
        browseUp.onclick = data.parent_url ? () => browseTo(data.parent_url) : null;
        browseList.innerHTML = '';
        if (data.entries.length === 0) {
          browseList.innerHTML = '<li class="sub">(empty folder)</li>';
        }
        for (const entry of data.entries) {
          const li = document.createElement('li');
          const btn = document.createElement('button');
          btn.type = 'button';
          btn.className = 'btn-inline secondary';
          btn.style.margin = '2px 0';
          btn.textContent = (entry.is_dir ? '📁 ' : '📄 ') + entry.name;
          if (entry.is_dir) {
            btn.addEventListener('click', () => browseTo(entry.url));
          } else {
            btn.addEventListener('click', () => {
              urlInput.value = entry.url;
              browsePanel.style.display = 'none';
            });
          }
          li.appendChild(btn);
          browseList.appendChild(li);
        }
      } catch (e) {
        browseList.innerHTML = '';
        browseError.textContent = e.message;
        browseError.style.display = 'block';
      }
    }

    browseToggle.addEventListener('click', () => {
      opened = !opened;
      browsePanel.style.display = opened ? 'block' : 'none';
      if (opened && !browseCurrent.textContent) {
        browseTo(null);
      }
    });
  }
}

function closeWhiteboardDialog() {
  // Nothing to tear down -- no poll interval, unlike the photos dialog.
}