Angular formArray/formGroup - Validate at least one checkbox was selected
TL;DR I prefer to use FormGroup to populate the list of checkbox Write a custom validator for check at least one checkbox was selected Working example
Recent Posts
Restrict null and undefined via Non-Nullable-Types in TypeScript
By default, null and undefined are assignable to all types in TypeScript.
Error handling in JavaScript. Synchronous vs asynchronous code
Error handling in JavaScript has been always straightforward, at least for synchronous code. Consider the following example:
TypeScript - Declare a function callback type
TL;DR To define the function callback type. You could declare interface that has a call signature. Or define a new type.
Angular [(ngModel)] and debounce
In AngularJS I can debounce a model by using ng-model options.
Casting a JSON object to a TypeScript class
TL;DR - To receive the JSON object from the server with all the methods available on the client side. For example the server send me a list of User. Inside t...
Freeze screen in Chrome debugger / DevTools panel for inspect element that will disappear on hover/click
Today I need to fix a small CSS issue of a time picker component. In order to debug the code, Chrome debugger will be used and I found it is not so straightf...
Angular render recursive view using *ngFor and ng-template
We’re all familiar with recursive view. One of the most common component that needed this technique is the nested navigation bar. The HTML structure and UI l...
Skiing in Singapore - a coding diversion
Hi there, it have been a while since my last post. Today I am re posting a quite interesting problem that I solved before.
npm - Check and update package if needed
I was planning to upgrade Angular to the latest version for quite sometimes but since I have sticked to Angular 5 for so long, the upgrading process was comp...
CSS Layout - Horizontal & Vertical Align
See the Pen centering-in-css-horizontal-vertical by Trung Vo (@trungk18) on CodePen.
How we handle time zone and locale at Zyllem
Hi there, in the big application that supports user from multiple countries should always have the support for selecting timezone and even their locale somew...
The myth of the Genius Programmer
It has been almost a month after my last post. Actually, I was so busy and drunk with the Lunar New Year but also had a good time with my family and friends ...
Angular Tips: Avoiding unnecessary RxJS in vendor.ts
About 1.5 years ago, Angular was officially released the so-called Angular 2 after years in beta version. I was excited about this and even came and ask my b...
Analyze webpack bundle with source-map-explorer. Optimize moment.js
Webpack is a module bundler which means that it bundles together all of your JavaScript files to one or multiple files commonly named bundle.js. If you want ...