👀 Views: 665 💬 Answers: 1 📅 Created: 2025-06-13

angularjs one-time-binding ng-if directive JavaScript

I'm working on a personal project and I'm working with an scenario with AngularJS 1.8 where I'm trying to efficiently update multiple views based on a single data source. I have a parent controller that fetches user data and passes it down to child components. However, I'm experiencing unexpected behavior when using one-time bindings in conjunction with `ng-if`. When the underlying data changes, some views update correctly while others do not, leading to inconsistent rendering.\n\nHere's a simplified version of my setup:\n\n```javascript\nangular.module('myApp', [])\n.controller('MainController', function($scope) {\n $scope.user = { name: 'John', age: 30 };\n $scope.updateUser = function() {\n $scope.user.age++; // Simulate an update\n };\n})\n.directive('userProfile', function() {\n return {\n restrict: 'E',\n scope: { user: '=' },\n template: '<div ng-if="user.name">Name: {{::user.name}}</div> <div ng-if="user.age">Age: {{::user.age}}</div>'\n };\n});\n```\n\nIn this directive, I am using a one-time binding (`::`) for both `name` and `age`. I expected that once the data is set, it wouldn't change, but I'm observing that the age does not update in the UI when I call `updateUser()`.\n\nI've tried removing the one-time binding and using normal two-way binding instead, but this led to unnecessary digest cycles that impacted performance, especially when there are multiple users being rendered in a list.\n\nWhen I check for errors in the console, I see no issues, which makes debugging even harder. Is there a better way to handle this scenario while maintaining performance? Any insights on when to use one-time bindings in conjunction with `ng-if` would be greatly appreciated! This is part of a larger API I'm building. What's the best practice here? What's the best practice here?