Refresh directive for concealing elements post authentication

Question

Refresh directive for concealing elements post authentication

Hey everyone,

I'm facing a situation where I need to display certain UI elements based on whether a session is active or not.

I initially tried using a directive for this purpose, and while it worked well, I encountered an issue where the directives wouldn't update after a successful login.

Previously, my code looked like this:

<ul class="nav navbar-nav navbar-right" ng-hide="vm.model.currentUser.id !== 0">

To improve clarity and organization, I decided to move the logic of checking the session status into a custom directive called:

<ul class="nav navbar-nav navbar-right" !ap-valid-login-session>

I have two questions regarding this approach:

Do you think this method is correct, or do you have any suggestions for a better alternative?
If this method is appropriate, how can I ensure that the directive gets recomputed when needed?

javascript angularjs angularjs-directive

Answer 1

Answer №1

When it comes to using the exclamation mark (!) in HTML, it's a no-go. This means that the second code snippet provided will not function as expected. However, by removing the exclamation mark and consolidating all logic into the directive responsible for adding and removing the 'hidden' class on an element, you may be able to get it working.

Yet, my preferred coding approach steers clear of directly manipulating HTML attributes and CSS classes within a directive. Mixing the presentation layer with business logic is considered poor separation of concerns from a software architecture perspective.

My suggestion would be to stick with the first code snippet but make a slight modification. Instead of embedding the Angular expression directly, I recommend creating a method call like so:

<ul class="nav navbar-nav navbar-right" ng-hide="isValidUser()">

In the directive file, define the method like this:

scope.isValidUser = function() { return vm.model.currentUser.id !== 0; }

By following this approach, you can benefit from:

Having more semantically meaningful HTML
Separation of business logic from presentation concerns
Easier writing of unit tests

Answer 2

When it comes to using the exclamation mark (!) in HTML, it's a no-go. This means that the second code snippet provided will not function as expected. However, by removing the exclamation mark and consolidating all logic into the directive responsible for adding and removing the 'hidden' class on an element, you may be able to get it working.

Yet, my preferred coding approach steers clear of directly manipulating HTML attributes and CSS classes within a directive. Mixing the presentation layer with business logic is considered poor separation of concerns from a software architecture perspective.

My suggestion would be to stick with the first code snippet but make a slight modification. Instead of embedding the Angular expression directly, I recommend creating a method call like so:

<ul class="nav navbar-nav navbar-right" ng-hide="isValidUser()">

In the directive file, define the method like this:

scope.isValidUser = function() { return vm.model.currentUser.id !== 0; }

By following this approach, you can benefit from:

Having more semantically meaningful HTML
Separation of business logic from presentation concerns
Easier writing of unit tests

Refresh directive for concealing elements post authentication

Answer №1

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