Fossil

  /**
     For use when installing a custom editor widget. Pass it the
     getter and setter callbacks to fetch resp. set the content of the
     custom widget. They will be triggered via
     P.wikiContent(). Returns this object.
  */
  P.setFileContentMethods = function(getter, setter){
  P.setContentMethods = function(getter, setter){
    this.wikiContent.get = getter;
    this.wikiContent.set = setter;
    return this;
  };

  /**
     Removes the default editor widget (and any dependent elements)

    if(!affirmPageLoaded()) return this;
    if(!content){
      callback(content);
      return this;
    }
    const fd = new FormData();
    const mimetype = this.e.selectMimetype.value;
    fd.append('page', this.winfo.name);
    fd.append('mimetype',mimetype);
    fd.append('content',content || '');
    F.message(
      "Fetching preview..."
    ).fetch('wikiajax/preview',{
      payload: fd,
      onload: (r,header)=>{

    F.message(
      "Fetching diff..."
    ).fetch('wikiajax/diff',{
      payload: fd,
      onload: function(c){
        target.innerHTML = [
          "<div>Diff <code>[",
          self.winfo.checkin,
          self.winfo.name,
          "]</code> &rarr; Local Edits</div>",
          c||'No changes.'
        ].join('');
        if(sbs) P.tweakSbsDiffs2();
        F.message('Updated diff.');
        self.tabs.switchToTab(self.e.tabs.diff);
      }