Convert exponential numbers to decimal form in Javascript

As almost every developers knows, Javascript has notorious problems when working with really big or really small decimal numbers. The reason is floating point. Purpose of this article is not to explain why it behaves the way it does, there are much better resources dedicated just for that. You can read the explanation here or here. There […]

Decimal number is not a number!

You have an input field, where user can enter decimal values. Problem is, that some cultures use decimal point “.” and some uses decimal comma “,”. So what is a valid number in one culture, is not a number at all in a different culture. You can see the full list of differences on wikipedia. There is no built-in […]

Angular – .map is not a function

I’ve encountered really weird error. After I’ve removed clearly unused code, our Angular app stopped working. It did however pass lint tests and also the production build passed without problems. The error occurred only during runtime. The error said something like “map is not a function at blablabla” and on the first glance it was totally […]

Invoke native element method with Angular 6

The useful method invokeElementMethod() has been removed from the new Renderer v3 in the upcoming version 6 of Angular. What does it mean? For example it is now harder to invoke focus() on input field or create custom native event, which bubbles up. The motivation of the Angular team is that this method has not been […]

Frozen global object

If your app uses global object as a config, you should make sure, that this object is truly readonly. So that an attacker can not modify it in dev console. This is how to do it. // example of frozen global object // freeze the config object properties const config = Object.freeze({ httpApi: ‘http://127.0.0.1:20003/v1’, wsApi: […]

Custom command line shortcuts with Doskey

I’ve learned this nice trick from Petr Horáček aka Besir while working on Nakamotox. So the credit goes to him. You can define custom commands via doskey (only on Windows) and then invoke them via command line. It is quite powerfull, because you can define alias for command with predefined attributes, so it save you lot of repetitive […]

Workaround for ExpressionChangedAfterItHasBeenCheckedError in async pipe

Imagine that you have this piece of code, where userInfo$ is Observable and it value is not yet emitted. <app-change-email [currentEmail]=”(userInfo$ | async).user.email”></app-change-email> The code works, but it will report error ExpressionChangedAfterItHasBeenCheckedError to the console (only in dev mode). That is because the component has received the value, but the value has changed later. Angular […]

Angular custom event bubbling

Custom events in Angular by default do not bubble up. It is because they are not really events, they are based on EventEmitter, which is similar to pub/sub mechanism. You can read lengthy discussion about it on Angular’s Github. Unfortunately the examples provided by Angular team often mention $event as named parameter in the event listener, […]