refactor checked function

server.js

@@ -118,12 +118,12 @@ if (env === 'production' && useHttps === 'true') {
   app.use(utils.forceHttps)
 }
 
-if (useAutoStoreData === 'true') {
-  app.use(utils.autoStoreData)
+var addCheckedFunction = function (app, nunjucksEnv) {
   app.use(function (req, res, next) {
-    // add nunjucks function to get values, needs to be here as they need access to req.session
+    // add nunjucks function called 'checked' to populate radios and checkboxes,
+    // needs to be here as it needs access to req.session and nunjucks environment
 
-    nunjucksAppEnv.addGlobal('checked', function (name, value) {
+    nunjucksEnv.addGlobal('checked', function (name, value) {
       if (req.session.data === undefined) {
         return ''
       }
@@ -144,31 +144,12 @@ if (useAutoStoreData === 'true') {
 
     next()
   })
+}
 
-  documentationApp.use(function (req, res, next) {
-    // add nunjucks function to get values, needs to be here as they need access to req.session
-
-    nunjucksDocumentationEnv.addGlobal('checked', function (name, value) {
-      if (req.session.data === undefined) {
-        return ''
-      }
-
-      var storedValue = req.session.data[name]
-
-      if (storedValue === undefined) {
-        return ''
-      }
-
-      if (Array.isArray(storedValue)) {
-        var inArray = storedValue.indexOf(value) !== -1
-        return inArray ? 'checked' : ''
-      } else {
-        return value === storedValue ? 'checked' : ''
-      }
-    })
-
-    next()
-  })
+if (useAutoStoreData === 'true') {
+  app.use(utils.autoStoreData)
+  addCheckedFunction(app, nunjucksAppEnv)
+  addCheckedFunction(documentationApp, nunjucksDocumentationEnv)
 }
 
 // Disallow search index idexing