BUGFIX Respecting server-overrides on X-Pjax responses during ajax re…

…directs. Fixes GridFieldDetailForm redirect after delete, e.g. in ModelAdmin. Partially reverts 8b4b896. Closes pull request #488

admin/code/LeftAndMain.php

@@ -351,6 +351,8 @@ function handleRequest(SS_HTTPRequest $request, DataModel $model = null) {
 	function redirect($url, $code=302) {
 		if($this->request->isAjax()) {
 			$this->response->addHeader('X-ControllerURL', $url);
+			if($header = $this->request->getHeader('X-Pjax')) $this->response->addHeader('X-Pjax', $header);
+			if($header = $this->request->getHeader('X-Pjax-Selector')) $this->response->addHeader('X-Pjax-Selector', $header);
 			return ''; // Actual response will be re-requested by client
 		} else {
 			parent::redirect($url, $code);

admin/javascript/LeftAndMain.Content.js

@@ -80,18 +80,14 @@
 				// as automatic browser ajax response redirects seem to discard the hash/fragment.
 				formData.push({name: 'BackURL', value:History.getPageUrl()});
 
-				// Some action buttons are redirecting to content areas as oposed to reloading the form.
-				// They will have pjax-content class on them.
-				var pjaxType = 'CurrentForm', pjaxSelector = '.cms-edit-form';
-				if ($(button).hasClass('pjax-content')) {
-					pjaxType = 'Content';
-					pjaxSelector = '.cms-content';
-				}
-
+				// Standard Pjax behaviour is to replace the submitted form with new content.
+				// The returned view isn't always decided upon when the request
+				// is fired, so the server might decide to change it based on its own logic,
+				// sending back different `X-Pjax` headers and content
 				jQuery.ajax(jQuery.extend({
 					headers: {
-						"X-Pjax" : pjaxType,
-						'X-Pjax-Selector': pjaxSelector
+						"X-Pjax" : "CurrentForm",
+						'X-Pjax-Selector': '.cms-edit-form'
 					},
 					url: form.attr('action'), 
 					data: formData,

admin/javascript/LeftAndMain.js

@@ -36,13 +36,13 @@ jQuery.noConflict();
 		$(document).ajaxComplete(function(e, xhr, settings) {
 			// Simulates a redirect on an ajax response.
 			if(window.History.enabled) {
-				var url = xhr.getResponseHeader('X-ControllerURL');
+				var url = xhr.getResponseHeader('X-ControllerURL'), opts, requestHeaders = settings.headers;
 				// Normalize trailing slashes in URL to work around routing weirdnesses in SS_HTTPRequest.
 				var isSame = (url && History.getPageUrl().replace(/\/+$/, '') == url.replace(/\/+$/, ''));
 				if(url && !isSame) {
-					var opts = {
-						pjax: settings.headers ? settings.headers['X-Pjax'] : null, 
-						selector: settings.headers ? settings.headers['X-Pjax-Selector'] : null
+					opts = {
+						pjax: xhr.getResponseHeader('X-Pjax') ? xhr.getResponseHeader('X-Pjax') : settings.headers['X-Pjax'], 
+						selector: xhr.getResponseHeader('X-Pjax-Selector') ? xhr.getResponseHeader('X-Pjax-Selector') : settings.headers['X-Pjax-Selector']
 					};
 					window.History.pushState(opts, '', url);
 				}
@@ -216,11 +216,14 @@ jQuery.noConflict();
 					state: state, element: contentEl
 				});
 
+				// Set Pjax headers, which can declare a preference for the returned view.
+				// The actually returned view isn't always decided upon when the request
+				// is fired, so the server might decide to change it based on its own logic.
 				var headers = {};
 				if(state.data.pjax) {
 					headers['X-Pjax'] = state.data.pjax;
 				} else {
-					// Replace full RHS content area
+					// Standard Pjax behaviour is to replace right content area
 					headers["X-Pjax"] = 'Content';
 				}
 				headers['X-Pjax-Selector'] = selector;

docs/en/reference/cms-architecture.md

@@ -183,6 +183,9 @@ Within the PHP logic, the `[api:PjaxResponseNegotiator]` class determines which
 Through a custom `X-Pjax` HTTP header, the client can declare which view he's expecting,
 through identifiers like `CurrentForm` or `Content` (see `[api:LeftAndMain->getResponseNegotiator()]`).
 These identifiers are passed to `loadPanel()` via the `pjax` data option.
+Keep in mind that the returned view isn't always decided upon when the Ajax request
+is fired, so the server might decide to change it based on its own logic,
+sending back different `X-Pjax` headers and content.
 
 ## Ajax Redirects
 

forms/gridfield/GridFieldDetailForm.php

@@ -291,9 +291,8 @@ function ItemEditForm() {
 		if($this->record->ID !== 0) {
 			$actions->push(FormAction::create('doSave', _t('GridFieldDetailForm.Save', 'Save'))
 				->setUseButtonTag(true)->addExtraClass('ss-ui-action-constructive')->setAttribute('data-icon', 'accept'));
-			// The delete action will redirect, hence pjax-content class.
 			$actions->push(FormAction::create('doDelete', _t('GridFieldDetailForm.Delete', 'Delete'))
-				->addExtraClass('ss-ui-action-destructive')->addExtraClass('pjax-content'));
+				->addExtraClass('ss-ui-action-destructive'));
 		}else{ // adding new record
 			//Change the Save label to 'Create'
 			$actions->push(FormAction::create('doSave', _t('GridFieldDetailForm.Create', 'Create'))
@@ -405,6 +404,7 @@ function doDelete($data, $form) {
 		//when an item is deleted, redirect to the revelant admin section without the action parameter
 		$controller = Controller::curr();
 		$noActionURL = $controller->removeAction($data['url']);
+		$controller->getRequest()->addHeader('X-Pjax', 'Content'); // Force a content refresh
 
 		return $controller->redirect($noActionURL, 302); //redirect back to admin section
 	}