Blog - kimserey lam

Rest

Nov 10th, 2017

Since the past 5 years, there has been an increasing demand to know how to build RESTful Web Services. Never had a job interview for Software Engineering failed to include at least one question about REST or RESTful Web Services and never a week passed with at least hearing one comment like “if we do x, it will not be RESTful”. Everyone seems to be on top of it, know everything about REST. But is it true? Do they really know REST? How certain can one be that her system is RESTful? Today I would like to share my point of view about REST.

Swagger For Aspnetcore

Nov 4th, 2017

Building a web API is not an easy task. In order to build one easy to use, we need to consider the routes, the HTTP methods, the return results from the endpoints, the parameter used for the body of the requests, etc… Swagger is a tool which compiles all our ApI endpoints into a user friendly UI and allows us to directly test our endpoints from the UI. Today we will see how we can integrate Swagger.

Microsoft Orleans Cluster Management

Oct 29th, 2017

Few weeks ago we saw how to create a Silo and how to implement grains. We also saw how we could create an ASP NET Core web app to talk to the Silo. We discovered the benefits of the single threaded model in grains. Today we will see one of the other major feature of Orleans, cluster management.

Microsoft Orleans Grains Concurrency

Oct 21st, 2017

Few weeks ago I explained the benefits of using Microsoft Orleans. One of them was the implementation of the actor pattern. Today I will dig deeper into it by revisiting a common scenario present in today systems and how it can be solved with Orleans grains.

Microsoft Orleans Application Sample

Oct 13th, 2017

Last week I presented an overview of Microsoft Orleans. Gave an explanation on the concepts and keywords which can be found in the framework. Today I will explain how we can implement a simple Orleans application with a cluster composed by a localhost Silo and with a client within an ASP Net Core Mvc application.

Microsoft Orleans Introduction

Oct 7th, 2017

Microsoft Orleans is a framework used to build scalable distributed systems. It reduces the complexity of distributed system by abstracting away concurrency issues and state management. Processes are ran on multiple instances and form a cluster, hosted on different environment and horizontally scalable on demand. Today I will give a broad overview of the concepts utilized and developed by the team behind Orleans.

Angular Primeng Breadcrumb Part2

Sep 28th, 2017

Last month I showed how we could build a breadcrumb with PrimeNG in Angular (you can read it as appetizer if you are interested in implementing a breadcrumb bar). In my previous post, I suggested to have a service BreadcrumbService which would hold the crumbs and get updated in ngOnInit of the component used on the route. Since then, I always was uncomfortable with this approach as this meant that my component would know the existance of a breadcrumb, because it updates it, while I always believed it should not know and not care. This led me to figure another way to abstract away from the component the concept of breadcrumb by combining guard, resolver and route.

Angular Reactive Form

Sep 22nd, 2017

Few weeks ago I explained how we could build reactive forms with Angular. In the previous post, I emphasized on how the reactiveness was enabling us to subscribe to the state and “react” to any state changes. Since then I have been playing quite a bit with the reactive form and more precisely with the FormBuilder. I ended up being more impressed by the link between FormGroup and UI rendering rather than about the reactiveness nature of the state held by the form. So today I would like to expand more on the FormBuilder by showing the steps needed to build a more complicated form supporting arrays of arrays and different controls like date picker and color picker.

Identity Server Implicit Flow Aspnetcore

Sep 16th, 2017

Few months ago I talked about Resource owner password flow with Identity Server and ASP NET Core. But as mentioned in multi places, ROP is an anti pattern when it comes down to a correct implementation of Open ID Connect. A more appropriate flow for API <-> SPA authentication is the Implicit flow. Today we will see how we can implement.

Serve Static Files Angular Cli

Sep 8th, 2017

One of the easiest way to build Angular applicationns is through Angular CLI. Using the ng serve command will build and serve the whole application or we can use ng build to output the app into the outputDir folder, but there might be occasions where we need to serve files which aren’t part of the Angular process, like static files or images. Those files are referred to as assets. Today we will see how we can configure Angular CLI to copy assets to the output directory and what sort of configuration is available.

Typescript Extension Methods

Sep 2nd, 2017

Typescript is a superset of JavaScript. It provides type safety on top of the JS libraries. Type safety is an important part of the development experience as it allows us to detect problems early thanks to the compiler preventing us from writing broken code. JS being dynamic it is very easy to extend since anything is assumed to exist. In the context of extension methods, the only step needed is to add the method to the prototype of the class and we are done. Typescript kept that flexibility but in order to provide type safety on top of it, extra steps are needed. Today I would like to share how we can create extension methods in Typescript by extending existing types.

Angular Breadcrumb Primeng

Aug 26th, 2017

The breadcrumb is a very important piece of any website. It gives an idea where the user is currently in, from where the user landed on this page and finally allow the user to navigate back to any steps wanted. I like to call it an “enhanced version of the URL path”. The URL path in itself has the information but it might, at time, not be human readable. That is where the breadcrumb become indispensable. I showed few features of PrimeNg in my previous posts about building an inline form and about building a tree structure. It turns out that they also provide a Angular friendly breadcrumb component. Today we will see how we can make use of the breadcrumb component together with the Angular router to provide a breadcrumb bar.

Angular Router Can Activate

Aug 19th, 2017

Few weeks ago I spoke about the functionality of the Angular Router http://kimsereyblog.blogspot.com/2017/05/attribute-route-in-asp-net-core.html. It was a brief overview of all the router features but one of the feature was not totally explain, the CanActivate feature. From there a question emerged, what is the difference between CanActivate and CanActivateChild?. Today I will answer this question and at the same time discussing extra behaviours of the router.

Angular Inline Form With Primeng

Aug 10th, 2017

Inline form are used to edit portion of long forms. This makes the process of editing a long form less tedious and less error prone as the focus is on a small portion. The process of allowing the fields to be editable can be hard as the state of the field currently selected for editing needs to be tracked and the right input fields must be shown. Angular offers convenient directives to handle showing and hiding elements, together with ngrx store to handle the state and PrimeNg UI components, it is an ideal solution to build inline forms. In this post we will see how to build a user friendly form.

Guard Routes Angular Ngrx

Aug 5th, 2017

Last month, I describe a way to manage global state with ngrx/store. With the store, we mamage the overal state of the Angular application in a single global object. Loading and retrieving data affects a single main state object. This simplication gives opportunities to other simplications. Like for example, if we loaded once a collection of items, we wouldn’t need to reload it when a component is displayed as it is available in the state. But how can we ensure that and more importantly how can we keep the check logic in a maintainable state. Here enter the Angular router route guard which I also described few weeks ago in my post on how we could create and manage routes with the Angular router. Today I will show how we can use both together to solve the issue of ensuring data is loaded before displaying a route.

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