Client friendly error handling

1 files changed, 57 insertions, 7 deletions

diff --git a/app/index.js b/app/index.js
index 719c424..419adfc 100644
--- a/app/index.js
+++ b/app/index.js
@@ -36,6 +36,7 @@ function OKCMS(options) {
   var templateRoot = options.templateRoot || 'templates';
   var adminTemplateRoot = options.templateRoot ||
     path.join(__dirname, '../themes/okadmin/templates');
+  var debug = options.debug || false;
 
   // Set metadata defaults
   // TODO Abstract this out somewhere else
@@ -84,13 +85,17 @@ function OKCMS(options) {
   });
   var resourceCache = this._resourceCache =
       this._createResources(resourceConfig, db, schemas);
+  var errorHandler = createErrorHandlerProducer(
+      templateProvider, adminTemplateProvider, debug);
 
   // Create view instances from config
   var views = this._views =
-      this._createViews(viewConfig, db, meta, resourceCache, templateProvider);
+      this._createViews(viewConfig, db, meta, resourceCache, templateProvider,
+          errorHandler);
   var adminViews = this._adminViews =
       this._createAdminViews(adminPath, app, express, resourceConfig,
-          resourceCache, adminTemplateProvider, adminMeta);
+          resourceCache, adminTemplateProvider, adminMeta,
+          errorHandler);
 
   // Create services
   var imageService = OKImageService({
@@ -109,7 +114,8 @@ function OKCMS(options) {
     adminPath: adminPath,
     services: {
       image: imageService
-    }
+    },
+    errorHandler: errorHandler
   });
 }
 
@@ -152,7 +158,7 @@ OKCMS.prototype._createResources = function(resourceConfig, db, schemaCache) {
 };
 
 OKCMS.prototype._createViews = function(viewConfig, db,
-    meta, resourceCache, templateProvider) {
+    meta, resourceCache, templateProvider, errorHandler) {
   viewConfig = viewConfig || {};
   var self = this;
   var createQueries = this._createQueries.bind(this);
@@ -171,7 +177,8 @@ OKCMS.prototype._createViews = function(viewConfig, db,
       route: route,
       template: template,
       queries: queries,
-      meta: meta
+      meta: meta,
+      errorHandler: errorHandler
     });
     return cache;
   }, {});
@@ -193,7 +200,8 @@ OKCMS.prototype._createViews = function(viewConfig, db,
 };
 
 OKCMS.prototype._createAdminViews = function(path, app, express,
-  resourceConfig, resourceCache, templateProvider, meta) {
+  resourceConfig, resourceCache, templateProvider, meta,
+  errorHandler) {
   var views = {};
   var withTrail = withTrailingSlash(path);
   var withoutTrail = withoutTrailingSlash(path);
@@ -217,7 +225,8 @@ OKCMS.prototype._createAdminViews = function(path, app, express,
     resourceConfig: resourceConfig,
     resourceCache: resourceCache,
     templateProvider: templateProvider,
-    meta: meta
+    meta: meta,
+    errorHandler: errorHandler
   });
   return views;
 };
@@ -269,6 +278,47 @@ ResourceCache.prototype.get = function(type, id) {
   }
 };
 
+/**
+ * Higher order function implementing customizable error handling
+ */
+function createErrorHandlerProducer(templateProvider, adminTemplateProvider, debugMode) {
+
+  var template404 = templateProvider.getTemplate('404') ||
+      adminTemplateProvider.getTemplate('404');
+  var template5xx = templateProvider.getTemplate('5xx') ||
+      adminTemplateProvider.getTemplate('5xx');
+
+  if (!template404 || !template5xx)
+    throw new Error('No error templates provided by admin theme or user')
+
+  return debugMode ? createDebugHandler : createErrorHandler;
+
+  function createErrorHandler(req, res, status) {
+    return function handleError(err) {
+      switch (status) {
+        case 404:
+          template404.render().then(function(rendered) {
+            res.status(status);
+            res.send(rendered);
+          });
+          break;
+        default:
+          template5xx.render().then(function(rendered) {
+            res.status(status);
+            res.send(rendered);
+          });
+      }
+
+    };
+  }
+
+  function createDebugHandler(req, res, status) {
+    return function handleError(err) {
+      res.send(err.stack);
+    };
+  }
+}
+
 module.exports = {
 
   createApp: function(options) {