Fossil

   of these properties:

   - onload: callback(responseData) (default = output response to the
   console). In the context of the callback, the options object is
   "this", noting that this call may have amended the options object
   with state other than what the caller provided.

   - onerror: callback(XHR onload event | exception) (default = event
   or exception to the console). Triggered if the request generates
   any response other than HTTP 200. In the context of the callback,
   the options object is "this".

   - method: 'POST' | 'GET' (default = 'GET'). CASE SENSITIVE!

   - payload: anything acceptable by XHR2.send(ARG) (DOMString,
   Document, FormData, Blob, File, ArrayBuffer), or a plain object or
   array, either of which gets JSON.stringify()'d. If payload is set
   then the method is automatically set to 'POST'. By default XHR2

   value of that single header. If it's an array, it's treated as a
   list of headers to return, and the 2nd argument is a map of those
   header values. When a map is passed on, all of its keys are
   lower-cased. When a given header is requested and that header is
   set multiple times, their values are (per the XHR docs)
   concatenated together with ", " between them.

   - beforesend/aftersend: optional callbacks which are called without
   arguments immediately before the request is submitted and
   immediately after it is received, regardless of success or
   error. In the context of the callback, the options object is the
   "this". These can be used to, e.g., keep track of in-flight
   requests and update the UI accordingly, e.g. disabling/enabling DOM
   elements. Any exceptions triggered by beforesend/aftersend are
   caught and silently ignored.

   When an options object does not provide
   onload/onerror/beforesend/aftersend handlers of its own, this
   function falls to defaults which are member properties of this
   function with the same name, e.g. fossil.fetch.onload(). The
   default onload/onerror implementations route the data through the
   dev console and (for onerror()) through fossil.error(). The default
   beforesend/aftersend are no-ops. Individual pages may overwrite
   those members to provide default implementations suitable for the
   page's use, e.g. keeping track of how many in-flight

   Returns this object, noting that the XHR request is asynchronous,
   and still in transit (or has yet to be sent) when that happens.
*/
window.fossil.fetch = function f(uri,opt){
  const F = fossil;
  if(!f.onload){

    };
  }
  if('/'===uri[0]) uri = uri.substr(1);
  if(!opt) opt = {};
  else if('function'===typeof opt) opt={onload:opt};
  if(!opt.onload) opt.onload = f.onload;
  if(!opt.onerror) opt.onerror = f.onerror;
  if(!opt.beforesend) opt.beforesend = f.beforesend;
  if(!opt.aftersend) opt.aftersend = f.aftersend;
  let payload = opt.payload, jsonResponse = false;
  if(undefined!==payload){
    opt.method = 'POST';
    if(!(payload instanceof FormData)
       && !(payload instanceof Document)
       && !(payload instanceof Blob)
       && !(payload instanceof File)

       the response. */
    jsonResponse = true;
    x.responseType = 'text';
  }else{
    x.responseType = opt.responseType||'text';
  }
  x.onload = function(e){
    try{opt.aftersend()}catch(e){/*ignore*/}
    if(200!==this.status){
      opt.onerror(e);
      return;
    }
    const orh = opt.responseHeaders;
    let head;
    if(true===orh){

                    ? JSON.parse(this.response) : this.response];
      if(head) args.push(head);
      opt.onload.apply(opt, args);
    }catch(e){
      opt.onerror(e);
    }
  };
  try{opt.beforesend()}catch(e){/*ignore*/}
  if(undefined!==payload) x.send(payload);
  else x.send();
  return this;
};

window.fossil.fetch.beforesend = function(){};
window.fossil.fetch.aftersend = function(){};

                        F.storage.storageImplName()),
               "):",
               sel, btnClear);
      D.attr(wrapper, "title", [
        'Locally-edited files. Timestamps are the last local edit time.',
        'Only the',P.config.defaultMaxStashSize,'most recent checkin/file',
        'combinations are retained.',
        'Committing or reloading a file removes it from this list.'
      ].join(' '));
      D.option(D.disable(sel), "(empty)");
      F.page.addEventListener('fileedit-stash-updated',(e)=>this.updateList(e.detail));
      F.page.addEventListener('fileedit-file-loaded',(e)=>this.updateList($stash, e.detail));
      sel.addEventListener('change',function(e){
        const opt = this.selectedOptions[0];
        if(opt && opt._finfo) P.loadFile(opt._finfo);

      forceEvent = true;
    }
    if(forceEvent){
      // Force UI update
      s.dispatchEvent(new Event('change',{target:s}));
    }
  };

  /**
     Keep track of how many in-flight AJAX requests there are so we
     can disable input elements while any are pending. For
     simplicity's sake we simply disable ALL OF IT while any AJAX is
     pending, rather than disabling operation-specific UI elements,
     which would be a huge maintenance hassle..
  */
  const ajaxState = {
    count: 0 /* in-flight F.fetch() requests */,
    toDisable: undefined /* elements to disable during ajax activity */
  };
  F.fetch.beforesend = function f(){
    if(!ajaxState.toDisable){
      ajaxState.toDisable = document.querySelectorAll(
        'button, input, select, textarea'
      );
    }
    if(1===++ajaxState.count){
      D.addClass(document.body, 'waiting');
      D.disable(ajaxState.toDisable);
    }
  };
  F.fetch.aftersend = function(){
    if(0===--ajaxState.count){
      D.removeClass(document.body, 'waiting');
      D.enable(ajaxState.toDisable);
    }
  };

  F.onPageLoad(function() {
    P.base = {tag: E('base')};
    P.base.originalHref = P.base.tag.href;
    P.tabs = new fossil.TabManager('#fileedit-tabs');
    P.e = { /* various DOM elements we work with... */
      taEditor: E('#fileedit-content-editor'),

/** Styles specific to /fileedit... */
body.fileedit.waiting * {
  /* Triggered during AJAX requests. */
  cursor: wait;
}
body.fileedit .error {
  padding: 0.25em;
}
body.fileedit .warning {
  padding: 0.25em;
}
body.fileedit textarea {