Using Apache Kafka for Asynchronous Communication in Microservices

  • In this post, we’ll look at how to set up an Apache Kafka instance, create a user service to publish data to topics, and build a notification service to consume data from those topics.
  • One of the required configuration options for the Kafka service is , which tells Kafka where to find the Zookeeper instance.
  • To publish data to a Kafka topic, we are going to create a user service that provides two endpoints: – – We use the NPM package to create a producer that connects to Kafka from our node app: – – We create a new promise object that resolves to a…
  • This is used in our function, which publishes data to a Kafka topic partition: – – To consume data from our Kafka topic, we are going to create a notification service that listens for data coming from our topics and sends an email with either a verification code or success…
  • Our two-factor authentication app demonstrates the communication pattern between only two microservices using Apache Kafka (there are other systems like RabbitMQ, ZeroMQ), but by decoupling communication between those services, we add flexibility for the future.

if you’re considering microservices, you have to give serious thought to how the different services will communicate. In this post, we’ll look at how to set up an Apache Kafka instance, create a user service to publish data to topics, and build a notification service to consume data from those topics.
Continue reading “Using Apache Kafka for Asynchronous Communication in Microservices”

Give React Native a(nother) try + ReactNative Navigation

  • React Native is no different from other – – tools in this regard, so I want to present a few reasons why you might want to give – – React Native a(nother) try now, just over two and a half years since its initial release.
  • # Native Navigation with React Navigation – – – – You start using React Native.
  • You can either use a library that wraps the native navigation APIs for the platform or a re-implementation of those APIs using the same React Native primitives (View, Text, Animated, etc) that you use throughout your app.
  • React Navigation (https://reactnavigation.org/) is a “JavaScript-based” navigation solution and React Native Navigation is a “native” navigation library.
  • I lead the React Navigation along with the creator of the project, Eric Vicenti.

Brent Vatne (expo.io, ReactNative) and Eric Vicenti (ReactNative @Facebook) are in town delivering training…# Reasons to give React Native a(nother) tryWhen a highly hyped new tool is released, many
Continue reading “Give React Native a(nother) try + ReactNative Navigation”

React stickers stickers

Check out our React JS #stickers

  • High quality, weather resistant and durable stickers to give your case the identity it deserves.
  • Your stickers are printed from a sheet vinyl, covered by a layer of top quality transparent film to protect the ink and improve durability and beauty, then finely cut to follow the shape.

Ultimate quality, top notch printing process, unique design React stickers stickers at Unixstickers, the largest unix, programming and software SWAG store. Free shipping available.
Continue reading “React stickers stickers”

Understanding State and Props in React – Hacker Noon

Understanding State and Props in React @RuairidhWM  #JavaScript #Reactjs #WebDev

  • Understanding State and Props in ReactI’ve been playing around with React and Redux recently and thought I would start writing articles on concepts which I’ve had to wrap my head around.So unless you’ve been living in a cave for the past few years, you’ll know that React is an awesome front-end library developed by the good folks at Facebook to make life easier for developers.It’s different to Angular or other frameworks as it is purely front-end (though see the comments below for a great clarification on this).
  • With that said, it’s extremely powerful.One of the concepts I struggled to understand during my learning more about React was the interaction between State and Props.
  • If you’re at all familiar with React then you should know that props flow downwards from the parent component.There is also the case that you can have default props so that props are set even if a parent component doesn’t pass props down.This is why people refer to React as having uni-directional data flow.
  • What happens when a component receives data from someone other than the parent?
  • This is super cool because that means React takes care of the hard work and is blazingly fast.As a little example of state, here is a snippet from a search bar (worth checking out this course if you want to learn more about React)Class SearchBar extends Component { constructor(props) { super(props);this.state = { term: ” }; }render() { return ( div className=”search-bar” input value={this.state.term} onChange={event = / /div ); }onInputChange(term) { this.setState({term}); }}SUMMARYProps and State do similar things but are used in different ways.

I’ve been playing around with React and Redux recently and thought I would start writing articles on concepts which I’ve had to wrap my head around. So unless you’ve been living in a cave for the…
Continue reading “Understanding State and Props in React – Hacker Noon”

react-native-aws-cognito

React Native module for authentication with #AWS Cognito.

  • Motivation to work on this module (and so, best use case) was having a secure, simple and cheap user management system that can access AWS IoT devices.
  • It supports Enhanced (Simplified) Authflow as described on are some limitations in this module:

    Sample code for retrieving signed url and using it to connect with AWS IoT using MQTT over Websocket:

React Native module for authenticating with AWS Cognito.
Continue reading “react-native-aws-cognito”

Understanding State and Props in React – Ruairidh Wynne-McHardy – Medium

Understanding State and Props in React  #javascript #development #react #es6 #reactjs

  • Understanding State and Props in ReactI’ve been playing around with React and Redux recently and thought I would start writing articles on concepts which I’ve had to wrap my head around.So unless you’ve been living in a cave for the past few years, you’ll know that React is an awesome front-end library developed by the good folks at Facebook to make life easier for developers.It’s different to Angular or other frameworks as it is purely front-end.
  • With that said, it’s extremely powerful.One of the concepts I struggled to understand during my learning more about React was the interaction between State and Props.
  • If you’re at all familiar with React then you should know that props flow downwards from the parent component.There is also the case that you can have default props so that props are set even if a parent component doesn’t pass props down.This is why people refer to React as having uni-directional data flow.
  • What happens when a component receives data from someone other than the parent?
  • This is super cool because that means React takes care of the hard work and is blazingly fast.As a little example of state, here is a snippet from a search bar (worth checking out this course if you want to learn more about React)Class SearchBar extends Component { constructor(props) { super(props);this.state = { term: ” }; }render() { return ( div className=”search-bar” input value={this.state.term} onChange={event = / /div ); }onInputChange(term) { this.setState({term}); }}SUMMARYProps and State do similar things but are used in different ways.

I’ve been playing around with React and Redux recently and thought I would start writing articles on concepts which I’ve had to wrap my head around. So unless you’ve been living in a cave for the…
Continue reading “Understanding State and Props in React – Ruairidh Wynne-McHardy – Medium”

A gentle Introduction to Higher Order Components

  • I want to pick out one use case, the conditional rendering with higher order components, to give you two outcomes from this article as a reader.
  • First, it should teach you about higher order components with the use case of conditional rendering.
  • Keep in mind, that altering the look of a component with a higher order component, specifically in the context of conditional rendering, is only one of several use cases to use HOCs.
  • In order to teach higher order components, the article focuses on the use case of conditional rendering.
  • Now you could use the higher order component but with a function that determines the conditional rendering.

Higher order components, or known under the abbreviation HOCs, are often a hard to grasp pattern in React. The article gives you an introduction to HOCs, how to use them elegantly in the case of conditional rendering and how to abstract them…
Continue reading “A gentle Introduction to Higher Order Components”

Develop React Native iOS apps on Linux – Santiago de León – Medium

Develop React Native #iOS apps on Linux:  #ReactJS #JavaScript

  • Develop React Native iOS apps on LinuxYes, you need a Mac to do any kind of iOS development but that doesn’t mean that you have to write the code in the Mac.
  • You can test this by starting any web server on your dev machine, binding it to that port and trying to reach http://DEV_MACHINE_IP:8585 with a web browser in your Mac.
  • So, I did: I fired up the packager in my dev box with react-native start –host 0.0.0.0 –port 8585 (setting the host to 0.0.0.0 is vital, because otherwise your server will only bind to localhost and won’t be accessible from your Mac).
  • I couldn’t find a setting to tell React Native to poll the packager service in a different host:port pair, so I figured that if I wanted it to access the server running in my dev machine, I had to do a TCP tunnel, which is actually quite easy to set up.
  • You’re all set!Make some changes to your React Native code in your dev machine, then hit Cmd+R in your Mac to see the changes.

Yes, you need a Mac to do any kind of iOS development but that doesn’t mean that you have to write the code in the Mac. You can actually write your code in whatever OS/editor combo you prefer and use…
Continue reading “Develop React Native iOS apps on Linux – Santiago de León – Medium”

Adding Users to the Node.js / React.js Neo4j Movie App

Adding Users to the #Nodejs / #Reactjs Neo4j Movie App


via @thesilverlogic

  • Once a user has logged in and navigated to a page that displays movies, the user can select a star rating for the movie or remove the rating of a movie he or she has already rated.
  • When a user visits their own profile, the user will see movie recommendations.
  • These users will be able to log in and out, rate movies, and receive movie recommendations.
  • Before a User can rate a Movie , the the user has to exist – someone has to sign up for an account.
  • Users with established tastes may be interested in finding movies with similar characteristics as his or her highly-rated movies, while not necessarily caring about whether another user has or hasn’t already rated the movie.

Learn how to add users and movie recommendation engine to the Neo4j Movie App Template using Node.js and React.js in addition to the Cypher query language.
Continue reading “Adding Users to the Node.js / React.js Neo4j Movie App”

React and third-party libraries

#ReactJS and third-party libraries:

  • It uses the Tags component that displays an unordered list based on the passed tags prop.
  • Component { render() { return (
      { this.props.tags.map((tag, i) =>

    • { tag }
    • ) }

    ); } }; // App.jsx class App extends React.

  • The very first thing that we have to do is to force a single-render of the Tags component.
  • class Tags extends React.
  • Every time when we click the button we update the state and trigger rerendering of Tags component.

React in patterns project. For other interesting patterns check out the repo.The example jQuery plugin for my example. It transforms an unordered list to input field for managing tags: plugin code. It works like that:. class. It uses the component that displays an unordered list based on the passed prop. When React renders the list on the screen we know that we have a tag so we can hook it to the jQuery plugin.Force a single-render component. That’s because when React adds the elements in the actual DOM we want to pass the control of them to jQuery. If we skip this both React and jQuery will work on same DOM elements without knowing for each other. To achieve a single-render we have to use the lifecycle method like so: here we are saying that our component will never rerender. If defined is used by React to understand whether to trigger or not. That’s ideal for our case because we want to place the markup on the page using React but we don’t want to rely on it after that.Initializing the pluginAPI for accessing actual DOM nodes. We have to use the attribute on a node and later reach that node via . is the proper lifecycle method for initializing the plugin. That’s because we get it called when React mounts the result of the method. lead to React rendering the with two items and then transforms it to a working tag editing widget.Controlling the plugin using React field. Such action will be triggered by the React component and needs to use the jQuery API. We have to find a way to communicate data to component but still keep the single-render approach. class and a button which if clicked will pass a string to component. component. However, because of we update nothing. The only one change is that we get a value of the prop which may be captured via another lifecycle method – : is a pure jQuery code. is a nice place for calling methods of the third-party library. component:Conclusion / blog of Krasimir Tsonev – front and back-end developer who writes for web technologies
Continue reading “React and third-party libraries”