The first time when i read Promise and Observable, there are some confusions. I realize that promise và observable are used for Asynchronous operations. But wait, if they are the same, why it’s not just be Promise or just be Observable :)). Now, follow me khổng lồ untie this knot.

The Promise object represents the eventual completion (or failure) of an asynchronous operation, & its resulting value. Promise is introduced in JS (ES6 standard)


new Promise(executor); new Promise(function(resolve, reject) ... ); Observables provide support for passing messages between publishers và subscribers in your application. Observables offer significant benefits over other techniques for sự kiện handling, asynchronous programming, and handling multiple values. “This isn’t an Angular specific feature, but rather a proposed standard for managing async data that will be included in the release of ES7. “


import Observable from “rxjs/Observable”
// create observable
const simpleObservable = new Observable((observer) =>
// observable execution“bla bla bla”)
// subscribe lớn the observable
// dispose the observable


src: StackOverFlow

Number of subscriber: Observable is lượt thích stream data in some language programming, is lazy loading, so observable can be canceled by using unsubscribed method, can have multiple subscribers at time.

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Return values & unsubscribed method: Opposite to lớn observable, Promise is only emits single event and value (array, object, number,…) at time while observable can provides many operators lượt thích foreach, filter, retry, map,…

Conclusion: Despite the differences, both is used for asynchronous operations, input is a function parameter, đầu ra return the latest result: error or not.



Solve: Tools->Nuget Package Manager->Brow CodeDom


I’m too busy. Sorry for the very short post. Bye bye

Before go khổng lồ this post, maybe you guys have known what is ReactJS. This tut only guides you to thiết lập React dev environment.

Requirement: NodeJS

Link download:

After complete setting up NodeJS, we create a thư mục name: React. Choose Git Bash/Open command window here.

Create React App

Create React App is a comfortable environment for learning React, and is the best way to lớn start building a new single-page application in React.

It sets up your development environment so that you can use the latest JavaScript features, provides a nice developer experience, và optimizes your tiện ích for production. You’ll need khổng lồ have Node >= 6 & npm >= 5.2 on your machine. To lớn create a project, run:

npx create-react-app my-app

cd my-app

npm start


npx on the first line is not a typo — it’s a package runner tool that comes with npm 5.2+.

After cài đặt ReactJs complete, enter:

cd Name-Of-ReactJs-Application

npm start

Go lớn http://localhost:3000/

This the first reactjs app, hope you guys learn ReactJS well.

Source: ReactJS

Because of some reasons, from this post i will write in English. If have any mistake or any inaccuracy in my posts, please keep calm & reminding me in a comfortable way. From N with love :”))

Today, i will bring you guys a a familiar glossaries: API, Restful API

What is API?


When you coding your web project at school, it’s just a small web, we need not khổng lồ separate it into more smaller components. When working with enterprise project, there are many features, the solution they use is separate it into smaller components (modules). How can these components interact with each other? API will responsible for this mission. Và when your web application wants lớn use Facebook login, Google login, this leads to need a Facebook/Google login API (In my opinion, this likely to embed other parts source code on your web, not directly). In other words, an application programming interface (API) is a set of subroutine definitions, communication protocols, và tools for building software. There are many types of API, one of most common API type is website API.

API can return popular type of values such as JSON, XML, YAML,…

API is not a language programming or something lượt thích that, it’s just a framework lớn build API website services for e.g Rest website services.

There are further types (3 main types) of web APIs such as Simple Object Access Protocol (SOAP), REST (Representation State Transfer), Remote Procedure hotline (RPC) – i will not go detail for this API in current post, but REST (Restful) have becomes so popular, we will investigate in detail in below section to lớn clarify what makes them RESTful & what these APIs are best used for. Web services use 3 types above (REST, RPC, SOAP) as a method to communicate, and HTTP is popular protocol in communicating. I recall website services because many people have a misunderstanding in recognition between API & Web services.


You can visit REST API for more information

In this post, Rest API is just entry level. REST is a type of API, we have some principles & constraints when designing a trang web base on “REST style”, the purpose is make based REST tiện ích more synchronize.

Like any other architectural style, REST also does have it’s own 6 guiding constraints which must be satisfied if an interface needs to lớn be referred as RESTful. These principles are listed below.

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6 Principle of REST:

Client–server – By separating the user interface concerns from the data storage concerns, we improve the portability of the user interface across multiple platforms và improve scalability by simplifying the vps components.Stateless – Each request from client to server must contain all of the information necessary to lớn understand the request, và cannot take advantage of any stored context on the server. Session state is therefore kept entirely on the client.Cacheable – Cache constraints require that the data within a response to a request be implicitly or explicitly labeled as cacheable or non-cacheable. If a response is cacheable, then a client cache is given the right khổng lồ reuse that response data for later, equivalent requests.Uniform interface – By applying the software engineering principle of generality khổng lồ the component interface, the overall system architecture is simplified and the visibility of interactions is improved. In order khổng lồ obtain a uniform interface, multiple architectural constraints are needed khổng lồ guide the behavior of components. REST is defined by four interface constraints: identification of resources; manipulation of resources through representations; self-descriptive messages; and, hypermedia as the engine of application state.Layered system – The layered system style allows an architecture to be composed of hierarchical layers by constraining component behavior such that each component cannot “see” beyond the immediate layer with which they are interacting.Code on demand (optional) – REST allows client functionality to lớn be extended by downloading và executing code in the khung of applets or scripts. This simplifies clients by reducing the number of features required to be pre-implemented.

REST defines 6 architectural constraints which make any web service – a true RESTful API.

Unlike SOAP (I will introduce more detail at next section), REST is not constrained to XML, but instead can return XML, JSON, YAML or any other format depending on what the client requests, people use JSON most in REST. & unlike RPC, users aren’t required khổng lồ know procedure names or specific parameters in a specific order.

REST APIs pros và cons i will discuss and compare it with SOAP in next few days, thank a lot. :”>

framework: là 1 thư viện các lớp để người dụng xây dựng ứng dụng. Như cái thương hiệu của nó “frame” chính là 1 bộ size sẵn có, lúc cần sử dụng người dùng chỉ cần gọi lại nó mà không cần phải tự thiết kế

VD: 1 framework trong lập rình website là lavarel

HTML: (tiếng Anh, viết tắt mang đến HyperText Markup Language, tốt là “Ngôn ngữ Đánh dấu siêu văn bản”) là một trong ngôn ngữ tấn công dấu được thiết kế theo phong cách ra để tạo cho các website với những mẩu tin tức được trình diễn trên World Wide Web.

CSS: chữ viết tắt của Cascading Style Sheets, nó làmột ngữ điệu được áp dụng để tìm với định dạng lại các phần tử được tạo thành bởi các ngôn ngữ đánh dấu (ví dụ như HTML).

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Javascript: là 1 ngôn ngữ lập trình web tất cả tính tương tác

PHP: viết tắt của chữ “Hypertext Preprocessor”, đây là một ngôn ngữ lập trình được thực hiện để viết ngơi nghỉ phía máy chủ (lập trình web). Hiện giờ có rất nhiều ngôn ngữ hoàn toàn có thể viết ở máy chủ như C#, Java, Python và PHP đó là một giữa những ngôn ngữ của tập thể nhóm này.

MVC: viết tắt của model – View – Controller. Là 1 trong những kiến trúc phần mềm hay mô hình xây dựng được sử dụng trong nghệ thuật phần mềm. Nói cho dễ hiểu, nó làmô hình phân bố source code thành 3 phần, từng thành phần có một nhiệm vụ cá biệt và độc lập với những thành phần khác