added basic error handling around templates rendering

services/web/app/coffee/Features/Templates/TemplatesWebController.coffee

@@ -7,13 +7,19 @@ module.exports = TemplatesWebController =
 	renderTemplatesIndexPage: (req, res)->
 		logger.log "rendering index page of templates"
 		TemplatesWebController._getDataFromTemplatesApi "/user/#{req.params.user_id}", (err, data)->
+			if err?
+				logger.err err:err, "something went wrong in renderTemplatesIndexPage"
+				return res.send 500
 			data.title = "LaTeX Templates"
 			res.render "templates/index", data
 
 	renerTemplateInTag: (req, res)->
-		logger.log "rendering latex template page"
 		{user_id, tag_name, template_name} = req.params
+		logger.log user_id:user_id, tag_name:tag_name, template_name:template_name, "rendering latex template page"
 		TemplatesWebController._getDataFromTemplatesApi "/user/#{user_id}/tag/#{tag_name}/template/#{template_name}", (err, data)->
+			if err?
+				logger.err err:err, user_id:user_id, tag_name:tag_name, template_name:template_name, "something went wrong in renerTemplateInTag"
+				return res.send 500
 			data.title = data.template.name
 			res.render "templates/template", data
 
@@ -37,28 +43,37 @@ module.exports = TemplatesWebController =
 			logger.error err: error, "templates proxy API error"
 			res.send 500
 
-	_renderCanonicalPage: _renderCanonicalPage = (req, res)->
+	_renderCanonicalPage: (req, res)->
 		{user_id, template_id} = req.params
 		logger.log user_id:user_id, template_id:template_id, "rendering template page"
 		TemplatesWebController._getDataFromTemplatesApi "/user/#{user_id}/template/#{template_id}", (err, data)->
+			if err?
+				logger.err err:err, user_id:user_id, template_id:template_id, "something went wrong in _renderCanonicalPage"
+				return res.send 500
 			data.tag = null
 			res.render "templates/template", data
 
-	_renderAllTemplatesPage: _renderAllTemplatesPage = (req, res)->
+	_renderAllTemplatesPage: (req, res)->
 		{user_id} = req.params
 		logger.log user_id:user_id, "rendering all templates page"
 		TemplatesWebController._getDataFromTemplatesApi "/user/#{user_id}/all", (err, data)->
+			if err?
+				logger.err err:err, user_id:user_id, "something went wrong in _renderCanonicalPage"
+				return res.send 500
 			data.title = "All Templates"
 			res.render "templates/tag", data
 
-	_renderTagPage: _renderTagPage = (req, res)->
+	_renderTagPage:  (req, res)->
 		{user_id, tag_name} = req.params
 		logger.log user_id:user_id, tag_name:tag_name, "rendinging tag page for templates"
 		TemplatesWebController._getDataFromTemplatesApi "/user/#{user_id}/tag/#{tag_name}", (err, data)->
+			if err?
+				logger.err err:err, user_id:user_id, tag_name:tag_name, "something went wrong in _renderCanonicalPage"
+				return res.send 500
 			data.title = data.tag.name
 			res.render "templates/tag", data
 
-	_getDataFromTemplatesApi: _getDataFromTemplatesApi = (path, callback)->
+	_getDataFromTemplatesApi: (path, callback)->
 		opts = 
 			url: "#{settings.apis.templates_api.url}#{path}"
 			json:true

services/web/test/UnitTests/coffee/Templates/TemplatesWebControllerTests.coffee

@@ -16,7 +16,9 @@ describe "TemplatesWebController", ->
 					url:"templates.sharelatex.env"
 		@TemplatesWebController = SandboxedModule.require modulePath, requires:
 			"settings-sharelatex":@settings
-			"logger-sharelatex": log:->
+			"logger-sharelatex": 
+				log:->
+				err:->
 		@stubbedApiData = 
 			template:{_id:"12312321", name:"bob"}
 			tag: {name:"tag name"}