Blog - kimserey lam

Nov 25, 2017

Aspnetcore And Angular Input Validation

Validation is an important part of the application development. There are two parts where validation is required, the API level and the frontend. The API validation is meant to prevent any malformed input to corrupt our data while the frontend validation is meant to guide the user to fill in a form by providing interactive feedback on her input. ASP NET Core for the backend and Angular for the frontend both ship with validation mechanisms fulfilling are requirements. Today we will see how we can implement validation in ASP NET Core using data annotation and inline validation with Angular reactive form.

Nov 18, 2017

Aspnetcore Patch With Json Patch

When building web APIs, most of the HTTP methods are implemented, GET, POST, PUT, PATCH and DELETE. While GET, POST and PUT are easily implemented, PATCH functionality is slightly different as it allows to change one or more properties of the resource. It is used to patch the resource. One way to do it is to use a protocol called JSON Patch. Today we will see how we can use JSON Patch through the ASP NET Core implementation and how we can construct the request from the frontend.

Nov 10, 2017

Rest

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.

Nov 04, 2017

Swagger For Aspnetcore

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.

Oct 29, 2017

Microsoft Orleans Cluster Management

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.

Oct 21, 2017

Microsoft Orleans Grains Concurrency

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.

Oct 13, 2017

Microsoft Orleans Application Sample

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.

Oct 07, 2017

Microsoft Orleans Introduction

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.

Sep 28, 2017

Angular Primeng Breadcrumb Part2

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.

Sep 22, 2017

Angular Reactive Form

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.

Sep 16, 2017

Identity Server Implicit Flow Aspnetcore

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.

Sep 08, 2017

Serve Static Files Angular Cli

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.

Sep 02, 2017

Typescript Extension Methods

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.

Aug 26, 2017

Angular Breadcrumb Primeng

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.

Aug 19, 2017

Angular Router Can Activate

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.