Fossil

  F.onPageLoad(function() {
    document.body.classList.add('pikchrshow');
    P.e = { /* various DOM elements we work with... */
      previewTarget: E('#pikchrshow-output'),
      previewLegend: E('#pikchrshow-output-wrapper > legend'),
      previewCopyButton: D.attr(
        D.addClass(D.span(),'copy-button'),
        'id','preview-copy-button' 
      ),
      previewModeLabel: D.label('preview-copy-button'),
      btnSubmit: E('#pikchr-submit-preview'),
      btnStash: E('#pikchr-stash'),
      btnUnstash: E('#pikchr-unstash'),
      btnClearStash: E('#pikchr-clear-stash'),

        return false;
      }
    }, false);

    ////////////////////////////////////////////////////////////
    // Setup clipboard-copy of markup/SVG...
    F.copyButton(P.e.previewCopyButton, {copyFromElement: P.e.taPreviewText});
    P.e.previewModeLabel.addEventListener('click', ()=>P.e.previewCopyButton.click(), false);

    ////////////////////////////////////////////////////////////
    // Set up dark mode simulator...
    P.e.cbDarkMode.addEventListener('change', function(ev){
      if(ev.target.checked) D.addClass(P.e.previewTarget, 'dark-mode');
      else D.removeClass(P.e.previewTarget, 'dark-mode');
    }, false);

    if(this.response.isError){
      D.append(D.clearElement(preTgt), D.parseHtml(P.response.raw));
      D.addClass(preTgt, 'error');
      this.e.previewModeLabel.innerText = "Error";
      return;
    }
    D.removeClass(preTgt, 'error');
    D.removeClass(this.e.previewCopyButton, 'disabled');
    D.removeClass(this.e.markupAlignWrapper, 'hidden');
    D.enable(this.e.previewModeToggle, this.e.markupAlignRadios);
    let label, svg;
    switch(this.previewMode){
    case 0:
      label = "SVG";
      f.showMarkupAlignment(false);

        P.response.isError = isError;
        D.enable(fp.toDisable);
        P.renderPreview();
      };
    }
    D.disable(fp.toDisable, this.e.previewModeToggle, this.e.markupAlignRadios);
    D.addClass(this.e.markupAlignWrapper, 'hidden');
    D.addClass(this.e.previewCopyButton, 'disabled');
    const content = this.e.taContent.value.trim();
    this.response.raw = this.response.rawSvg = undefined;
    this.response.inputText = content;
    const sampleScript = fp.$_sampleScript;
    delete fp.$_sampleScript;
    if(sampleScript && sampleScript.cached){
      fp.updateView(sampleScript.cached, false);