force immediate avatar update

Zotlabs/Module/Profile_photo.php

@@ -180,6 +180,8 @@ class Profile_photo extends \Zotlabs\Web\Controller {
 						dbesc(datetime_convert()),
 						dbesc($channel['xchan_hash'])
 					);
+					// Similarly, tell the nav bar to bypass the cache and update the avater image.
+					$_SESSION['reload_avatar'] = true;
 	
 					info( t('Shift-reload the page or clear browser cache if the new photo does not display immediately.') . EOL);
 	

include/nav.php

@@ -255,6 +255,19 @@ $powered_by = '';
 		'$pleasewait' => t('Please wait...')
 	));
 
+
+	if(x($_SESSION, 'reload_avatar') && $observer) {
+		// The avatar has been changed on the server but the browser doesn't know that, 
+		// force the browser to reload the image from the server instead of its cache.
+		$tpl = get_markup_template('force_image_reload.tpl');
+
+		App::$page['nav'] .= replace_macros($tpl, array(
+			'$imgUrl' => $observer['xchan_photo_m']
+		));
+		unset($_SESSION['reload_avatar']);
+	}
+
+
 	call_hooks('page_header', App::$page['nav']);
 }
 

view/tpl/force_image_reload.tpl

@@ -0,0 +1,72 @@
+{{* 
+Force the browser to reload an image from the server instead of the cache.
+based on an answer from http://stackoverflow.com/a/22429796/3343347
+
+Usage: Set $imgUrl to the src url you want to be re-fetched from the server
+
+*}}
+
+<script>
+  $(document).ready(
+    function() {
+      forceImgReload("{{$imgUrl}}");
+    }
+  );
+
+  {{* 
+    * find and return any existing img tags with a matching src url, and set them to an intermediate 
+    * src url so they can later be reverted back once the cached version has been updated.
+    *}}
+  function prepareImagesForReload(srcUrl) {
+
+    var result = $("img[src='" + srcUrl + "']").get();
+
+    for (i = 0; i < result.length; i++) {
+      {{* 
+        * Set the image to a reloading image, in this case an animated "reloading" svg 
+        * Ideally this wont be displayed long enough to matter.
+        *}}
+      result[i].src = "data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100' preserveAspectRatio='xMidYMid' class='uil-reload'%3E%3Cpath fill='none' class='bk' d='M0 0h100v100H0z'/%3E%3Cg%3E%3Cpath d='M50 15a35 35 0 1 0 24.787 10.213' fill='none' stroke='%23777' stroke-width='12'/%3E%3Cpath d='M50 0v30l16-15L50 0' fill='%23777'/%3E%3CanimateTransform attributeName='transform' type='rotate' from='0 50 50' to='360 50 50' dur='1s' repeatCount='indefinite'/%3E%3C/g%3E%3C/svg%3E";
+    }
+
+    return result;
+  }
+
+  function restoreImages(srcUrl, imgList) {
+
+    for (i = 0; i < imgList.length; i++) {
+      imgList[i].src = srcUrl;
+    }
+  }
+
+  function forceImgReload(srcUrl) {
+    var imgList;
+    var step = 0; 
+    var iframe = window.document.createElement("iframe");   // Hidden iframe, in which to perform the load+reload.
+  
+    {{* Callback function, called after iframe load+reload completes (or fails).
+        Will be called TWICE unless twostage-mode process is cancelled. (Once after load, once after reload). *}}
+    var iframeLoadCallback = function(e) { 
+
+      if (step === 0) { 
+        // initial load just completed.  Note that it doesn't actually matter if this load succeeded or not.
+      
+        step = 1; 
+        imgList = prepareImagesForReload(srcUrl); 
+        iframe.contentWindow.location.reload(true); // initiate forced-reload!
+      
+      } else if (step === 1) {
+        // forced re-load is done 
+
+        restoreImages(srcUrl, imgList);
+        if (iframe.parentNode) iframe.parentNode.removeChild(iframe);
+      }
+    }
+
+    iframe.style.display = "none";
+    window.parent.document.body.appendChild(iframe); {{* NOTE: if this is done AFTER setting src, Firefox MAY fail to fire the load event! *}}
+    iframe.addEventListener("load",  iframeLoadCallback, false);
+    iframe.addEventListener("error", iframeLoadCallback, false);
+    iframe.src = srcUrl;  
+  }
+</script>