fix relative string models in hideExpression and watchers

kwypchlo commented 8 years ago

What

Previously discussed on my previous PR https://github.com/formly-js/angular-formly/pull/599#issuecomment-172775380

expect breaking change

String hideExpression and watchers were evaluated in context of $scope.model unlike expressionProperties that were evaluated in the context of the model of a field. That said when you had nested model like const model = {nested: {foo: 'bar'}}; and your field would have model declared as a string model: 'model.nested' your hideExpression and watcher would vary from expressionProperties:

hideExpression: 'model.nested.foo === "bar"'
expressionProperties: {
  'some.property': 'model.foo === "bar"'
},
watcher: {
  expression: 'model.nested.foo === "bar"',
  listener: function() {}
}

After my tweaks, watchers and hideExpressions that are string-based, are evaluated in the same model context as expressionProperties which is only logical.

hideExpression: 'model.foo === "bar"'
expressionProperties: {
  'some.property': 'model.foo === "bar"'
},
watcher: {
  expression: 'model.foo === "bar"',
  listener: function() {}
}

Why

hideExpression and expressionProperties should be as similar to developer as possible - the mechanism behind them can be different but their api and behavior should be the same thus expression copied from expressionProperty should work with hideExpression and vice versa
watchExpression was by default 'model.' + key which didn't work out of a box for nested models because fe. const model = {nested: {foo: 'bar'}}; with model: 'model.nested', watcherExpression would be model.foo because of watchExpression = 'model[\'' + field.key.toString().split('.').join('\'][\'') + '\']' and this would not work because it didn't take into account that model was moved to nested child and would expect model.nested.foo to work
How

I have added 2 things:

in method getFormlyFieldLikeLocals that prepares context for field expressions registered in formly-form controller to look more like these registered from the formly-field controller. getFormlyFieldLikeLocals has one time that field.model is not yet ready - this is on initModel method call that actually resolves field.model and should be run in $scope.model context. Other than that, anything that uses getFormlyFieldLikeLocals should be run with model as field.model.
watchExpression in formly watcher registration gets run through $parse to add field.model as a model

Checklist:

[x] Follows the commit message conventions
[x] Is rebased with master
[x] Is only one (maybe two) commits

I might add a test or two to confirm watchers behavior but wanted to post this PR for first review

codecov-io commented 8 years ago

Current coverage is `96.03%`

Merging #639 into master will increase coverage by +0.02% as of d1b47ba

@@            master    #639   diff @@
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  Files           16      16       
  Stmts         1155    1160     +5
  Branches         0       0       
  Methods          0       0       
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+ Hit           1109    1114     +5
  Partial          0       0       
  Missed          46      46

Review entire Coverage Diff as of d1b47ba