- Patch #28483 by Steven: JavaScript enabled uploading.

  Comment from Steven: It does this by redirecting the submission of the form to a hidden <iframe> when you click "Attach" (we cannot submit data through Ajax directly because you cannot read file contents from JS for security reasons).  Once the file is submitted, the upload-section of the form is updated.  Things to note:

    * The feature degrades back to the current behaviour without JS.
    * If there are errors with the uploaded file (disallowed type, too big, ...), they are displayed at the top of the file attachments fieldset.
    * Though the hidden-iframe method sounds dirty, it's quite compact and is 100% implemented in .js files. The drupal.js api makes it a snap to use.
    * I included some minor improvements to the Drupal JS API and code.
    * I added an API drupal_call_js() to bridge the PHP/JS gap: it takes a function name and arguments, and outputs a <script> tag. The kicker is that it preserves the structure and type of arguments, so e.g. PHP associative arrays end up as objects in JS.
    * I also included a progressbar widget that I wrote for drumm's ongoing update.php work. It includes Ajax status updating/monitoring, but it is only used as a pure throbber in this patch. But as the code was already written and is going to be used in the near future, I left that part in. It's pretty small ;). If PHP supports ad-hoc upload info in the future like Ruby on Rails, we can implement that in 5 minutes.

6 files changed, 222 insertions, 4 deletions

diff --git a/misc/autocomplete.js b/misc/autocomplete.js
index 52702909d..0f4eee475 100644
--- a/misc/autocomplete.js
+++ b/misc/autocomplete.js
@@ -17,10 +17,9 @@ function autocompleteAutoAttach() {
       if (!acdb[uri]) {
         acdb[uri] = new ACDB(uri);
       }
-      id = input.id.substr(0, input.id.length - 13);
-      input = document.getElementById(id);
+      input = $(input.id.substr(0, input.id.length - 13));
       input.setAttribute('autocomplete', 'OFF');
-      input.form.onsubmit = autocompleteSubmit;
+      addSubmitEvent(input.form, autocompleteSubmit);
       new jsAC(input, acdb[uri]);
     }
   }
diff --git a/misc/drupal.css b/misc/drupal.css
index 258fd8791..a8366dd37 100644
--- a/misc/drupal.css
+++ b/misc/drupal.css
@@ -579,6 +579,28 @@ input.throbbing {
 }
 
 /*
+** Progressbar styles
+*/
+.progress {
+  font-weight: bold;
+}
+.progress .bar {
+  background: #fff url('progress.gif');
+  border: 1px solid #00375a;
+  height: 1.5em;
+  margin-top: 0.2em;
+}
+.progress .filled {
+  background: #0072b9;
+  height: 1.33em;
+  border-bottom: 0.67em solid #004a73;
+  width: 0%;
+}
+.progress .percentage {
+  float: right;
+}
+
+/*
 ** Collapsing fieldsets
 */
 html.js fieldset.collapsed {
diff --git a/misc/drupal.js b/misc/drupal.js
index 80414afb0..4007817c4 100644
--- a/misc/drupal.js
+++ b/misc/drupal.js
@@ -102,6 +102,42 @@ function HTTPPost(uri, object, callbackFunction, callbackParameter) {
 }
 
 /**
+ * Redirects a button's form submission to a hidden iframe and displays the result
+ * in a given wrapper. The iframe should contain a call to
+ * window.parent.iframeHandler() after submission.
+ */
+function redirectFormButton(uri, button, handler) {
+  // Insert the iframe
+  var div = document.createElement('div');
+  div.innerHTML = '<iframe name="redirect-target" id="redirect-target" src="" style="width:0px;height:0px;border:0;"></iframe>';
+  button.parentNode.appendChild(div);
+
+  // Trap the button
+  button.onfocus = function() {
+    button.onclick = function() {
+      // Prepare vars for use in anonymous function.
+      var button = this;
+      var action = button.form.action;
+      var target = button.form.target;
+      // Redirect form submission
+      this.form.action = uri;
+      this.form.target = 'redirect-target';
+      handler.onsubmit();
+      // Set iframe handler for later
+      window.iframeHandler = function (data) {
+        // Restore form submission
+        button.form.action = action;
+        button.form.target = target;
+        handler.oncomplete(data);
+      }
+    }
+  }
+  button.onblur = function() {
+    button.onclick = null;
+  }
+}
+
+/**
  * Adds a function to the window onload event
  */
 function addLoadEvent(func) {
@@ -118,6 +154,21 @@ function addLoadEvent(func) {
 }
 
 /**
+ * Adds a function to the window onload event
+ */
+function addSubmitEvent(form, func) {
+  var oldSubmit = form.onsubmit;
+  if (typeof oldSubmit != 'function') {
+    form.onsubmit = func;
+  }
+  else {
+    form.onsubmit = function() {
+      return oldSubmit() && func();
+    }
+  }
+}
+
+/**
  * Retrieves the absolute position of an element on the screen
  */
 function absolutePosition(el) {
@@ -196,7 +247,7 @@ function eregReplace(search, replace, subject) {
  */
 function removeNode(node) {
   if (typeof node == 'string') {
-    node = document.getElementById(node);
+    node = $(node);
   }
   if (node && node.parentNode) {
     return node.parentNode.removeChild(node);
@@ -205,3 +256,10 @@ function removeNode(node) {
     return false;
   }
 }
+
+/**
+ * Wrapper around document.getElementById().
+ */
+function $(id) {
+  return document.getElementById(id);
+}
diff --git a/misc/progress.gif b/misc/progress.gif
new file mode 100644
index 000000000..3564e7b06
--- /dev/null
+++ b/misc/progress.gif
diff --git a/misc/progress.js b/misc/progress.js
new file mode 100644
index 000000000..b4e4c9039
--- /dev/null
+++ b/misc/progress.js
@@ -0,0 +1,80 @@
+/**
+ * A progressbar object. Initialized with the given id. Must be inserted into
+ * the DOM afterwards through progressBar.element.
+ *
+ * e.g. pb = new progressBar('myProgressBar');
+ *      some_element.appendChild(pb.element);
+ */
+function progressBar(id) {
+  var pb = this;
+  this.id = id;
+
+  this.element = document.createElement('div');
+  this.element.id = id;
+  this.element.className = 'progress';
+  this.element.innerHTML = '<div class="percentage"></div>'+
+                           '<div class="status">&nbsp;</div>'+
+                           '<div class="bar"><div class="filled"></div></div>';
+}
+
+/**
+ * Set the percentage and status message for the progressbar.
+ */
+progressBar.prototype.setProgress = function (percentage, status) {
+  var divs = this.element.getElementsByTagName('div');
+  for (i in divs) {
+    if (percentage >= 0) {
+      if (hasClass(divs[i], 'filled')) {
+        divs[i].style.width = percentage + '%';
+      }
+      if (hasClass(divs[i], 'percentage')) {
+        divs[i].innerHTML = percentage + '%';
+      }
+    }
+    if (hasClass(divs[i], 'status')) {
+      divs[i].innerHTML = status;
+    }
+  }
+}
+
+/**
+ * Start monitoring progress via Ajax.
+ */
+progressBar.prototype.startMonitoring = function (uri, delay) {
+  this.delay = delay;
+  this.uri = uri;
+  this.sendPing();
+}
+
+/**
+ * Stop monitoring progress via Ajax.
+ */
+progressBar.prototype.stopMonitoring = function () {
+  clearTimeout(this.timer);
+}
+
+/**
+ * Request progress data from server.
+ */
+progressBar.prototype.sendPing = function () {
+  if (this.timer) {
+    clearTimeout(this.timer);
+  }
+  HTTPGet(this.uri, this.receivePing, this);
+}
+
+/**
+ * HTTP callback function. Passes data back to the progressbar and sets a new
+ * timer for the next ping.
+ */
+progressBar.prototype.receivePing = function(string, xmlhttp, pb) {
+  if (xmlhttp.status != 200) {
+    return alert('An HTTP error '+ xmlhttp.status +' occured.\n'+ pb.uri);
+  }
+  // Split into values
+  var matches = string.length > 0 ? string.split('|') : [];
+  if (matches.length >= 2) {
+    pb.setProgress(matches[0], matches[1]);
+  }
+  pb.timer = setTimeout(function() { pb.sendPing(); }, pb.delay);
+}
diff --git a/misc/upload.js b/misc/upload.js
new file mode 100644
index 000000000..48f403448
--- /dev/null
+++ b/misc/upload.js
@@ -0,0 +1,59 @@
+// Global killswitch
+if (isJsEnabled()) {
+  addLoadEvent(uploadAutoAttach);
+}
+
+/**
+ * Attaches the upload behaviour to the upload form.
+ */
+function uploadAutoAttach() {
+  var acdb = [];
+  var inputs = document.getElementsByTagName('input');
+  for (i = 0; input = inputs[i]; i++) {
+    if (input && hasClass(input, 'upload')) {
+      var uri = input.value;
+      var button = input.id.substr(5);
+      var wrapper = button + '-wrapper';
+      var hide = button + '-hide';
+      var upload = new jsUpload(uri, button, wrapper, hide);
+    }
+  }
+}
+
+/**
+ * JS upload object.
+ */
+function jsUpload(uri, button, wrapper, hide) {
+  var upload = this;
+  this.button = button;
+  this.wrapper = wrapper;
+  this.hide = hide;
+  redirectFormButton(uri, $(button), this);
+}
+
+/**
+ * Handler for the form redirection submission.
+ */
+jsUpload.prototype.onsubmit = function () {
+  var hide = $(this.hide);
+  // Insert progressbar and stretch to take the same space.
+  this.progress = new progressBar('uploadprogress');
+  this.progress.setProgress(-1, 'Uploading file...');
+  this.progress.element.style.width = '28em';
+  this.progress.element.style.height = hide.offsetHeight +'px';
+  hide.parentNode.insertBefore(this.progress.element, hide);
+  // Hide file form
+  hide.style.display = 'none';
+}
+
+/**
+ * Handler for the form redirection completion.
+ */
+jsUpload.prototype.oncomplete = function (data) {
+  // Remove progressbar
+  removeNode(this.progress);
+  this.progress = null;
+  // Replace form and re-attach behaviour
+  $(this.wrapper).innerHTML = data;
+  uploadAutoAttach();
+}
\ No newline at end of file