A Reading List

Creating PWA Using Angular 7 – Step-by-Step Guide

A rather long and detailed post about Angular and PWA (Progressive Web App), but worth the read, especially if you haven’t heard about PWA. It covers the 101 stuff and goes on to creating PWA using Angular.


How to use Azure Bastion to connect securely to your Azure VMs

Great new offering from Azure. If you always RDP to your VM in Azure, or use a _’jump box’_, you will have a new, better, more secure way to RDP now. I really like the name too!


Lessons from Design School for Software Engineers

They are great lessons software engineers can adopt to become better. Not a technical post, but related to technical. It’s more of philosophical-type post, which is always good to know.


The Battle of C# to JSON Serializers in .NET Core 3

There’s a new kid in town, it’s called `System.Text.Json`. Michael goes over how the comparison between this new .NET Core 3 feature and other JSON libraries, including the infamous Json.NET. And yes, it cover performance test as well.


How to resolve .NET reference and NuGet package version conflicts

Have you ever got one of those annoying, `Could not load file or assembly or one of its dependencies` error when running .NET locally? Not only Michael explains why, but he also tell you how to resolve it. Mystery solved.


List to Read

The emerging big data architectural pattern

An Azure post about big data architecture. If you are about to start one, this is a good introduction. It mainly focuses on Lambda architect (batch and speed layers) using Azure resources.


Roadmap for learning the JavaScript language

Do you just start learning JavaScript? Are you planning to master JavaScript? This post is for you. Learn JavaScript from the early version and how it evolve to current version.


Choosing the right frontend database for a single page application

And if you are now serious about PWA, check this article out on what’s the ‘right’ frontend database for your app. Very useful especially when you are starting a new project.


Turn your Angular App into a PWA in 4 Easy Steps

Now you know what’s PWA, you can turn your existing Angular app into a PWA. Looks pretty straigh-forward honestly. But the devil is always in the details, right?


Progressive Web Apps & Electron

You can’t talk about PWA without Electron app. But, what’s the difference? Well, check this post out to find the answer. In short, they are like siblings, similar but different.


Integrate Ionic in Existing Angular Project

Angular Project

I just finished my project, written in Angular and although it runs on mobile browsers, it needs to be deployed as a native application. The choice is obvious, Ionic.

I’m integrating Ionic for Android development, but it’s optional. You don’t have to prepare your Ionic project for Android development, if you don’t want to. The same concept can also be used to prepare your project for iOS development.

This applies to:

  • Angular 7.
  • Ionic 5.
  • Java SDK 8 update 202.
  • Android SDK 9.0 (API level 28)
  • Android Studio 3.3.2

Here’s my approach integrating Ionic in my Angular project.

Bring-in Ionic

The step includes creating a new project using Ionic CLI, I’m going to refer it as Ionic project while my original Angular project as, well, Angular project.

  • In your Angular project, update all npm packages, to the latest major if you can. This is to avoid version conflict with Ionic project’s npm packages.
  • Start a new Ionic blank project.
    ionic start project-name blank
    
  • Update all npm packages in the newly created Ionic project.
    npm i -g npm-check-updates && ncu -u
    
  • Copy ionic.config.json from Ionic project to Angular project.
  • Copy angular.json from Ionic project to Angular project.
    • If you have specifically changed anything in your angular.json, make that necessary changes in the Angular project after the copy.
    • Ionic uses SCSS for style sheet by default, so if you are not using SCSS, make sure to copy settings under projects/app/architect/**/options/styles from Angular project’s angular.json prior to copy.
    • integrate-ionic-in-angular-project-1
  • Copy package.json from Ionic project to Angular project.
      • If you have specifically changed anything in your package.json (npm scripts, etc), make that necessary changes in the Angular project after the copy.
      • Combine the npm packages from both projects setting under dependencies and devDependencies.
      • integrate-ionic-in-angular-project-2

     

  • Combine .gitignore files from both projects, if you are using Git source control.
  • In Angular project, delete package-lock.json file and node_modules folder. These should be located in root of the project.
  • In Angular project, run npm install command.
    npm install
    
  • Test and make sure everything runs.
    // Test run with Ionic
    ionic serve
    // Test run with Angular
    ng serve --open
    
  • If you want to prepare your project for Cordova, runs the following command. Note that environment setup is required. Please refer to reference section for more details.
    // For Android
    ionic cordova prepare android
    // For iOS
    //ionic cordova prepare ios
    

References

Barebone Angular with D3 v5

Just uploaded Github project showcasing sample Angular project with D3 v5.

The project contain implementation of D3 v5 in Angular project and consist of most popular D3 features such as Basic shape, Animation, Chart, Dragging and Zooming. Each sample is self-contained. D3 dependencies can be seen on `package.json`.
Time permitting, I will add more samples in the future.

For D3 new-comers, check out this resources explaining most important concepts in D3, Selection, Joins and if you work with chart, Scale.

NgRx Entity

NgRx Entity

NgRx Entity is a library to handle entity within NgRx framework. The entity in the context is defined as the application’s domain objects, like User, Employee, etc.

The purposes of NgRx Entity are basically:

  • Reduce boilerplate code.
  • Search and sort entities quickly.

The first thing we need to use NgRx Entity is to create an entity adapter, like so:

const adapter = createEntityAdapter();

NgRx Entity also defines `EntityState<>` interface. The interface is also extensible should the additional properties in the application state are needed,

The shape of EntityState is something like this:

interface EntityState {
  ids: string[];
  entities: { [id: string]: V };
}

What this allows us to do is:

  • Find entity quickly using `entities` dictionary.
  • Maintain order of the list, good for use in sorting.

Some boilerplate codes that are reduced when using NgRx Entity:

  • No need to specify properties of the state interface.
  • Add, remove, update of entities in the state are handled by entity adapter.
  • Entity adapter has most commonly used selectors.

Reference

https://medium.com/ngrx/introducing-ngrx-entity-598176456e15

NgRx State Selectors

NgRx State Selectors

As our application grows, the data structure that represents the application states could get more complex. State data structure in ngRx is tree-like and in the early development, the structure may only have few properties. As the application grows, the structure could have deep nested objects.

When states have deep nested objects, we will have to write more code to select the slice of state. Something like:

// Complex data structure
let state = {
    products: {
        pizza: {
            name: "Pepperoni",
            amount: 4
        },
        topping: {
            name: "mushroom",
            amount: 3
        }
    }
};

// Selecting pizza state
let pizza = state.products.pizza;

Selecting pizza state requires dot notation and it’s also prone to error where products is undefined, that line of code will blow up.

Another issue with this is that we will have to write the same line of code to get pizza state every where we need the state.

This is where state selectors in ngRx comes in. It allows us to define selectors for our states and use it everywhere in our application.

There are mainly 2 state selectors, createFeatureSelector and createSelector. The first one mainly deals with state at the root level while the second one can be used to select a specific object in the state (for example, pizza or topping).

Reference

https://toddmotto.com/ngrx-store-understanding-state-selectors

NgRx Store Explained

NgRx Store

ngRx Store is a library for Angular 2+, its function is almost like event bus where the store is a central storage for all events and whenever an event is added, the store emits an action. Whoever subscribe to the store‘s action will then get notified. Very similar to pub-sub pattern.

The purpose of ngRx Store is to simplify the state management, that sometime can be simple at first but, as the application grows, becomes unimaginably complicated.

Some example usage of ngRx Store that I can think right now are:

  • Forward execution. When an Angular application sends an API call to update, let’s say, employee data, it doesn’t need to call API anymore to query what the current employee data is. However, things get complicated when there’s a certain logic needs to be applied when updating employee data. For example, when the hire date is set to the future, the employee status will also need to be changed. ngRx Store can be used to manage the employee state so that it remains consistent at every part of the application.
  • Reduce extraneous props. Extraneous prop is when we have a deep component tree and have to pass object around to the leaf component. ngRx Store eliminates the need of passing the object around and just have the leaf component subscribe to the `store` to receive the action. A concrete example of this is notification counter. The counter is normally in its own component and every other event can increase the count. By using ngRx Store, we can avoid other components passing the count to the counter component.
  • Sort of the similar to extraneous props, we can have 2, or more, components that use the same data but display it differently. With ngRx Store, we can manage the state of the data in one place and all other components that use the data just subscribe to it.
  • Step-by-step, wizard-y workflow. Think of this like your tax filing software where it asks you questions and, depend on your answer, take you to different workflow. In Angular, each step the users take can use a separate component and ngRx Store can be used to maintain the state of the whole workflow process.

The problem that ngRx Store trying to solve is really similar to challenges that a large scale enterprise application faces, it just does it in a smaller scale, UI front-end in this case.

There’s definitely a lot more to this concept than what I cover here, but hopefully this gives you the gist of how it works at the high level. There are lots of resources online that cover this very topic.