Using telnet as a tool for troubleshooting network port connections

Note that you may need to enable telnet on your workstation (see this Article: How to enable telnet for troubleshooting when CMD reports: “‘telnet’ is not recognized as an internal or external command”)

Once you have telnet enabled, follow these steps:

  1. Open a command prompt
  2. Type in “telnet <IP ADDRESS OF SERVER PC> <PORT>” and press enter.
  3. For example, you would type “telnet 123.45.67.89 1521”
  4. If a blank screen appears then the port is open, and the test is successful.
  5. If you receive a connecting… message or an error message then something is blocking that port.  It could be the Windows firewall, a third party firewall like your anti-virus software, or an institutional hardware firewall between the workstation and the server.

Source: Using telnet as a tool for troubleshooting connection problems on hosted Voyager servers – Ex Libris Knowledge Center

Rxjs debugging subscribers

I wanted to see how many listeners there was for a certain subject, and where they reside in the source code.
Here is how in chrome devtools, put a breakpoint before the subjects .next() call. And inspect the subject:

observers array count = number of “listeners”
FunctionLocation = source code reference

(Context: Angular v11, rxjs)

Introduction to Angular Storybook – a tool for component UI development

Introduction to Storybook for Angular Storybook is a tool for UI development. It makes development faster and easier by isolating components. This allows you to work on one component at a time. You can develop entire UIs without needing to start up a complex dev stack, force certain data into your database, or navigate around your application.

Source: Introduction to Storybook

A simpler and smaller Angular starter project

A lot of complaints I heard when starting with Angular are about the sheer amount of files you get even on simple apps. When looking at the default starter template you get from Angular CLI’s ng new command, it’s true that it can be a bit overwhelming if you’re not used to it.

But it doesn’t have to always be that way. In this article, we’ll explore how we can create a smaller and simpler template that’s also easier to grasp for beginners, following the YAGNI principle.

(Angular version 14)
Source: A simpler and smaller Angular starter with ngLite – DEV Community

Use of Enums in Angular 8+ HTML template

in the TS

import { SomeEnum } from 'path-to-file';

public get SomeEnum() {
  return SomeEnum; 
}

in the HTML use

*ngIf="SomeEnum.someValue === 'abc'"

EDIT: Time goes by and we learn more as a developer, the approach I’m using right now doesn’t use the get method. Both solutions work, just choose the one you like the most.

in the TS

import { SomeEnum } from 'path-to-file';

export class ClassName {
  readonly SomeEnum = SomeEnum;
}

in the HTML use

*ngIf="SomeEnum.someValue === 'abc'"

From: Use of Enums in Angular 8 HTML template for *ngIf – Stack Overflow