feat(formly-field): Adds parser for keys that contain arrays (#709)

angular. does not (and will not angular/angular.js#9850) properly
handle arrays in keys unless they have already been created in the model. This fix/feature adds a
separate parser for these circumstances and a formlyConfig.extras flag to control its use. The flag
is in place to minimize impact on current functionality of the setter.

This is in support of #706

src/directives/formly-field.js

@@ -35,7 +35,7 @@ function formlyField($http, $q, $compile, $templateCache, $interpolate, formlyCo
 
   // @ngInject
   function FormlyFieldController($scope, $timeout, $parse, $controller, formlyValidationMessages) {
-    /* eslint max-statements:[2, 34] */
+    /* eslint max-statements:[2, 37] */
     if ($scope.options.fieldGroup) {
       setupFieldGroup()
       return
@@ -109,6 +109,24 @@ function formlyField($http, $q, $compile, $templateCache, $interpolate, formlyCo
       return angular.isNumber(key) || !formlyUtil.containsSelector(key)
     }
 
+    function keyContainsArrays(key) {
+      return /\[\d{1,}\]/.test(key)
+    }
+
+    function deepAssign(obj, prop, value) {
+      if (angular.isString(prop)) {
+        prop = prop.replace(/\[(\w+)\]/g, '.$1').split('.')
+      }
+
+      if (prop.length > 1) {
+        const e = prop.shift()
+        obj[e] = obj[e] || (isNaN(prop[0])) ? {} : []
+        deepAssign(obj[e], prop, value)
+      } else {
+        obj[prop[0]] = value
+      }
+    }
+
     function parseSet(key, model, newVal) {
       // If either of these are null/undefined then just return undefined
       if ((!key && key !== 0) || !model) {
@@ -118,6 +136,8 @@ function formlyField($http, $q, $compile, $templateCache, $interpolate, formlyCo
       if (shouldNotUseParseKey(key)) {
         // TODO: Fix this so we can get several levels instead of just one with properties that are numeric
         model[key] = newVal
+      } else if (formlyConfig.extras.parseKeyArrays && keyContainsArrays(key)) {
+        deepAssign($scope.model, key, newVal)
       } else {
         const setter = $parse($scope.options.key).assign
         if (setter) {

src/directives/formly-field.test.js

@@ -566,6 +566,20 @@ describe('formly-field', function() {
       expect(scope.model[key]).to.eq(defaultValue)
     })
 
+    it('should handle arrays properly when formlyConfig.extras.parseKeyArrays is set', () => {
+      const key = 'foo[0]'
+      const defaultValue = 'bar'
+
+      formlyConfig.extras.parseKeyArrays = true
+      scope.fields = [
+        {template: input, key, defaultValue},
+      ]
+      scope.model = {}
+
+      compileAndDigest()
+      expect(scope.model.foo).to.be.instanceof(Array)
+    })
+
     it('should get and set values when key is alpha numeric with alpha first', () => {
       const key = 'A1'
       const defaultValue = 'bar'

src/providers/formlyApiCheck.js

@@ -166,6 +166,7 @@ const formOptionsApi = apiCheck.shape({
   resetModel: apiCheck.func.optional,
   updateInitialValue: apiCheck.func.optional,
   removeChromeAutoComplete: apiCheck.bool.optional,
+  parseKeyArrays: apiCheck.bool.optional,
   templateManipulators: templateManipulators.optional,
   manualModelWatcher: apiCheck.oneOfType([apiCheck.bool, apiCheck.func]).optional,
   watchAllExpressions: apiCheck.bool.optional,

src/providers/formlyConfig.js

@@ -28,6 +28,7 @@ function formlyConfig(formlyUsabilityProvider, formlyErrorAndWarningsUrlPrefix,
       fieldTransform: [],
       ngModelAttrsManipulatorPreferUnbound: false,
       removeChromeAutoComplete: false,
+      parseKeyArrays: false,
       defaultHideDirective: 'ng-if',
       getFieldId: null,
     },