How to Tips for Building Engaging WYSIWYG Editors

In the past four years, I have been responsible for building a lot of WYSIWYG (What You See Is What You Get) editors. I recently completed work on the most challenging one so far, an editor for Apple Wallet and Google Pay Passes.

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How to Tips for Building Engaging WYSIWYG Editors
Reid  Rohan

Reid Rohan

1663025940

10 Best Libraries for JavaScript Editors

In today's post we will learn about 10 Best Libraries for JavaScript Editors. 

What’s an Editor?
Let’s start with editors. Text editors are exactly what their name suggest: programs that allow you to create and edit plain-text files. That’s it. An editor, in the classical sense, isn’t necessarily a programming tool; you could it to edit text files for any purpose. One of such purposes is, of course, writing code.

Table of contents:

  • ACE - Ace (Ajax.org Cloud9 Editor).
  • CodeMirror - In-browser code editor.
  • Esprima - ECMAScript parsing infrastructure for multipurpose analysis.
  • Quill - A cross browser rich text editor with an API.
  • Medium-editor - Medium.com WYSIWYG editor clone.
  • Pen - enjoy live editing (+markdown).
  • JQuery-notebook - A simple, clean and elegant text editor. Inspired by the awesomeness of Medium.
  • Bootstrap-wysiwyg - Tiny bootstrap-compatible WYSIWYG rich text editor.
  • Ckeditor-releases - The best web text editor for everyone.
  • Editor - A markdown editor. still on development.
  • EpicEditor - An embeddable JavaScript Markdown editor with split fullscreen editing, live previewing, automatic draft saving, offline support, and more.
  • JSoneditor - A web-based tool to view, edit and format JSON.
  • Vim.js - JavaScript port of Vim with a persistent ~/.vimrc.

1 - ACE: Ace (Ajax.org Cloud9 Editor).

Ace is a standalone code editor written in JavaScript. Our goal is to create a browser based editor that matches and extends the features, usability and performance of existing native editors such as TextMate, Vim or Eclipse. It can be easily embedded in any web page or JavaScript application. Ace is developed as the primary editor for Cloud9 IDE and the successor of the Mozilla Skywriter (Bespin) Project.

Take Ace for a spin!

Check out the Ace live demo or get a Cloud9 IDE account to experience Ace while editing one of your own GitHub projects.

If you want, you can use Ace as a textarea replacement thanks to the Ace Bookmarklet.

Embedding Ace

Ace can be easily embedded into any existing web page. You can either use one of pre-packaged versions of ace (just copy one of src* subdirectories somewhere into your project), or use requireJS to load contents of lib/ace as ace

The easiest version is simply:

<div id="editor">some text</div>
<script src="src/ace.js" type="text/javascript" charset="utf-8"></script>
<script>
    var editor = ace.edit("editor");
</script>

With "editor" being the id of the DOM element, which should be converted to an editor. Note that this element must be explicitly sized and positioned absolute or relative for Ace to work. e.g.

#editor {
    position: absolute;
    width: 500px;
    height: 400px;
}

To change the theme simply include the Theme's JavaScript file

<script src="src/theme-twilight.js" type="text/javascript" charset="utf-8"></script>

and configure the editor to use the theme:

editor.setTheme("ace/theme/twilight");

By default the editor only supports plain text mode; many other languages are available as separate modules. After including the mode's JavaScript file:

<script src="src/mode-javascript.js" type="text/javascript" charset="utf-8"></script>

The mode can then be used like this:

var JavaScriptMode = ace.require("ace/mode/javascript").Mode;
editor.session.setMode(new JavaScriptMode());

to destroy editor use

editor.destroy();
editor.container.remove();

View on Github

2 - CodeMirror: In-browser code editor.

CodeMirror is a versatile text editor implemented in JavaScript for the browser. It is specialized for editing code, and comes with over 100 language modes and various addons that implement more advanced editing functionality. Every language comes with fully-featured code and syntax highlighting to help with reading and editing complex code.

Installation

Either get the zip file with the latest version, or make sure you have Node installed and run:

npm install codemirror

NOTE: This is the source repository for the library, and not the distribution channel. Cloning it is not the recommended way to install the library, and will in fact not work unless you also run the build step.

Quickstart

To build the project, make sure you have Node.js installed (at least version 6) and then npm install. To run, just open index.html in your browser (you don't need to run a webserver). Run the tests with npm test.

View on Github

3 - Esprima: ECMAScript parsing infrastructure for multipurpose analysis.

Esprima (esprima.org, BSD license) is a high performance, standard-compliant ECMAScript parser written in ECMAScript (also popularly known as JavaScript). Esprima is created and maintained by Ariya Hidayat, with the help of many contributors.

API

Esprima can be used to perform lexical analysis (tokenization) or syntactic analysis (parsing) of a JavaScript program.

A simple example on Node.js REPL:

> var esprima = require('esprima');
> var program = 'const answer = 42';

> esprima.tokenize(program);
[ { type: 'Keyword', value: 'const' },
  { type: 'Identifier', value: 'answer' },
  { type: 'Punctuator', value: '=' },
  { type: 'Numeric', value: '42' } ]
  
> esprima.parseScript(program);
{ type: 'Program',
  body:
   [ { type: 'VariableDeclaration',
       declarations: [Object],
       kind: 'const' } ],
  sourceType: 'script' }

For more information, please read the complete documentation.

View on Github

4 - Quill: A cross browser rich text editor with an API.

Quill is a modern rich text editor built for compatibility and extensibility. It was created by Jason Chen and Byron Milligan and actively maintained by Slab.

Quickstart

Instantiate a new Quill object with a css selector for the div that should become the editor.

<!-- Include Quill stylesheet -->
<link href="https://cdn.quilljs.com/1.0.0/quill.snow.css" rel="stylesheet" />

<!-- Create the toolbar container -->
<div id="toolbar">
  <button class="ql-bold">Bold</button>
  <button class="ql-italic">Italic</button>
</div>

<!-- Create the editor container -->
<div id="editor">
  <p>Hello World!</p>
</div>

<!-- Include the Quill library -->
<script src="https://cdn.quilljs.com/1.0.0/quill.js"></script>

<!-- Initialize Quill editor -->
<script>
  var editor = new Quill('#editor', {
    modules: { toolbar: '#toolbar' },
    theme: 'snow',
  });
</script>

Take a look at the Quill website for more documentation, guides and live playground!

Download

CDN

<!-- Main Quill library -->
<script src="//cdn.quilljs.com/1.0.0/quill.js"></script>
<script src="//cdn.quilljs.com/1.0.0/quill.min.js"></script>

<!-- Theme included stylesheets -->
<link href="//cdn.quilljs.com/1.0.0/quill.snow.css" rel="stylesheet" />
<link href="//cdn.quilljs.com/1.0.0/quill.bubble.css" rel="stylesheet" />

<!-- Core build with no theme, formatting, non-essential modules -->
<link href="//cdn.quilljs.com/1.0.0/quill.core.css" rel="stylesheet" />
<script src="//cdn.quilljs.com/1.0.0/quill.core.js"></script>

View on Github

5 - Medium-editor: Medium.com WYSIWYG editor clone.

MediumEditor has been written using vanilla JavaScript, no additional frameworks required.

Basic usage

Demo

demo: http://yabwe.github.io/medium-editor/

Installation

Via npm:

Run in your console: npm install medium-editor

Via bower:

bower install medium-editor

Via an external CDN

For the latest version:

<script src="//cdn.jsdelivr.net/npm/medium-editor@latest/dist/js/medium-editor.min.js"></script>
<link rel="stylesheet" href="//cdn.jsdelivr.net/npm/medium-editor@latest/dist/css/medium-editor.min.css" type="text/css" media="screen" charset="utf-8">

For a custom one:

<script src="//cdn.jsdelivr.net/npm/medium-editor@5.23.2/dist/js/medium-editor.min.js"></script>
<link rel="stylesheet" href="//cdn.jsdelivr.net/npm/medium-editor@5.23.2/dist/css/medium-editor.min.css" type="text/css" media="screen" charset="utf-8">

Manual installation:

Download the latest release and attach medium editor's stylesheets to your page:

Find the files to below mentioned linking in the dist folder. (./medium-editor/dist/...)

<link rel="stylesheet" href="css/medium-editor.css"> <!-- Core -->
<link rel="stylesheet" href="css/themes/default.css"> <!-- or any other theme -->

Usage

The next step is to reference the editor's script

<script src="js/medium-editor.js"></script>

You can now instantiate a new MediumEditor object:

<script>var editor = new MediumEditor('.editable');</script>

The above code will transform all the elements with the .editable class into HTML5 editable contents and add the medium editor toolbar to them.

You can also pass a list of HTML elements:

var elements = document.querySelectorAll('.editable'),
    editor = new MediumEditor(elements);

MediumEditor also supports textarea. If you provide a textarea element, the script will create a new div with contentEditable=true, hide the textarea and link the textarea value to the div HTML content.

Integrating with various frameworks

People have contributed wrappers around MediumEditor for integrating with different frameworks and tech stacks. Take a look at the list of existing Wrappers and Integrations that have already been written for MediumEditor!

View on Github

6 - Pen: Enjoy live editing (+markdown).

Source code

You can clone the source code from github, or using bower.

bower install pen

Installation

init with id attribute

var editor = new Pen('#editor');

init with an element

var editor = new Pen(document.getElementById('editor'));

init with options

var options = {
  editor: document.body, // {DOM Element} [required]
  class: 'pen', // {String} class of the editor,
  debug: false, // {Boolean} false by default
  textarea: '<textarea name="content"></textarea>', // fallback for old browsers
  list: ['bold', 'italic', 'underline'], // editor menu list
  linksInNewWindow: true // open hyperlinks in a new windows/tab
}

var editor = new Pen(options);

Configure

The following object sets up the default settings of Pen:

defaults = {
  class: 'pen',
  debug: false,
  textarea: '<textarea name="content"></textarea>',
  list: [
    'blockquote', 'h2', 'h3', 'p', 'insertorderedlist', 'insertunorderedlist',
    'indent', 'outdent', 'bold', 'italic', 'underline', 'createlink'
  ],
  stay: true,
  linksInNewWindow: false
}

If you want to customize the toolbar to fit your own project, you can instanciate Pen constructor with an options object like #1.3: init with options:

Fallback for old browser

You can set defaults.textarea to a piece of HTML string, by default, it's <textarea name="content"></textarea>。This will be set as innerHTML of your #editor.

Change the editor class

Pen will add .pen to your editor by default, if you want to change the class, make sure to replace the class name pen to your own in src/pen.css.

View on Github

7 - JQuery-notebook: A simple, clean and elegant text editor. Inspired by the awesomeness of Medium.

A simple, clean and elegant WYSIWYG rich text editor for web aplications

Usage

Prerequisites: jQuery-Notebook's default styling FontAwesome draw the icons on the context bubble. You can install both FontAwesome and jQuery-Notebook through bower with the following command:

bower install jquery-notebook font-awesome

Alternatively, you can download FontAwesome here or link to the CDN.

Add the FontAwesome css and jQuery-Notebook css to you page head:

<link href="http://netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.css" rel="stylesheet">
<link rel="stylesheet" type="text/css" href="src/js/jquery.notebook.css">

Add jquery and jquery-notebook.js to your page:

<script type="text/javascript" src="src/js/libs/jquery-1.10.2.min.js"></script>
<script type="text/javascript" src="src/js/jquery.notebook.js"></script>

Create the editor:

<div class="my-editor"></div>
$(document).ready(function(){
    $('.my-editor').notebook();
});

That's it!

Available Commands

  • Ctrl/Command B - Bold
  • Ctrl/Command I - Italic
  • Ctrl/Command U - Underline
  • Ctrl/Command F1 - Header 1
  • Ctrl/Command F2 - Header 2
  • Ctrl/Command Z - Undo

View on Github

8 - Bootstrap-wysiwyg: Tiny bootstrap-compatible WYSIWYG rich text editor.

About the editor

Tiny bootstrap-compatible WISWYG rich text editor, based on browser execCommand, built originally for MindMup. Here are the key features:

  • Automatically binds standard hotkeys for common operations on Mac and Windows
  • Drag and drop files to insert images, support image upload (also taking photos on mobile devices)
  • Allows a custom built toolbar, no magic markup generators, enabling the web site to use all the goodness of Bootstrap, Font Awesome and so on...
  • Does not force any styling - it's all up to you
  • Uses standard browser features, no magic non-standard code, toolbar and keyboard configurable to execute any supported browser command
  • Does not create a separate frame, backup text areas etc - instead keeps it simple and runs everything inline in a DIV
  • (Optionally) cleans up trailing whitespace and empty divs and spans
  • Requires a modern browser (tested in Chrome 26, Firefox 19, Safari 6)
  • Supports mobile devices (tested on IOS 6 Ipad/Iphone and Android 4.1.1 Chrome)

Basic Usage

See http://mindmup.github.com/bootstrap-wysiwyg/

Customising

You can assign commands to hotkeys and toolbar links. For a toolbar link, just put the execCommand command name into a data-edit attribute. For more info on execCommand, see http://www.quirksmode.org/dom/execCommand.html and https://developer.mozilla.org/en/docs/Rich-Text_Editing_in_Mozilla

<div class="btn-toolbar" data-role="editor-toolbar" data-target="#editor">
  <a class="btn btn-large" data-edit="bold"><i class="icon-bold"></i></a>
</div>

To pass arguments to a command, separate a command with a space.

 <a data-edit="fontName Arial">...</a>

You can also use input type='text' with a data-edit attribute. When the value is changed, the command from the data-edit attribute will be applied using the input value as the command argument

<input type="text" data-edit="createLink">

If the input type is file, when a file is selected the contents will be read in using the FileReader API and the data URL will be used as the argument

<input type="file" data-edit="insertImage">

To change hotkeys, specify the map of hotkeys to commands in the hotKeys option. For example:

$('#editor').wysiwyg({
  hotKeys: {
    'ctrl+b meta+b': 'bold',
    'ctrl+i meta+i': 'italic',
    'ctrl+u meta+u': 'underline',
    'ctrl+z meta+z': 'undo',
    'ctrl+y meta+y meta+shift+z': 'redo'
  }
});

View on Github

9 - Ckeditor-releases: The best web text editor for everyone.

Releases Code

This repository contains the official release versions of CKEditor 4.

There are four versions for each release — standard-all, basic, standard, and full. They differ in the number of plugins that are compiled into the main ckeditor.js file as well as the toolbar configuration.

See the comparison of the basic, standard, and full installation presets for more details.

The standard-all build includes all official CKSource plugins with only those from the standard installation preset compiled into the ckeditor.js file and enabled in the configuration.

All versions available in this repository were built using CKBuilder, so they are optimized and ready to be used in a production environment.

Installation

Git clone

To install one of the available releases, just clone this repository and switch to the respective branch (see next section):

git clone -b <release branch> git://github.com/ckeditor/ckeditor4-releases.git

Git submodule

If you are using git for your project and you want to integrate CKEditor, we recommend to add this repository as a submodule.

git submodule add -b <release branch> git://github.com/ckeditor/ckeditor-releases.git <clone dir>
git commit -m "Added CKEditor submodule in <clone dir> directory."

Using Package Managers

See the Installing CKEditor with Package Managers article for more details about installing CKEditor with Bower, Composer and npm.

View on Github

10 - Editor: A markdown editor. still on development.

Overview

Editor is not a WYSIWYG editor, it is a plain text markdown editor. Thanks for the great project codemirror, without which editor can never be created.

Basic Usage

The easiest way to use Editor is to simply load the script and stylesheet:

<link rel="stylesheet" href="http://lab.lepture.com/editor/editor.css" />
<script type="text/javascript" src="http://lab.lepture.com/editor/editor.js"></script>
<script type="text/javascript" src="http://lab.lepture.com/editor/marked.js"></script>

You can also use jsdelivr CDN:

<link rel="stylesheet" href="//cdn.jsdelivr.net/editor/0.1.0/editor.css">
<script src="//cdn.jsdelivr.net/editor/0.1.0/editor.js"></script>
<script src="//cdn.jsdelivr.net/editor/0.1.0/marked.js"></script>

Having done this, an editor instance can be created:

var editor = new Editor();
editor.render();

The editor will take the position of the first <textarea> element.

Get the content

To get back the edited content you use:

editor.codemirror.getValue();

Component

If you are using component, you can install it with:

$ component install lepture/editor

View on Github

Thank you for following this article.

Related videos:

Top 10 Best Rich Text HTML JavaScript Editor 

#javascript #editor 

Ajay Kapoor

1619522210

5 Top Web Design and Development Tips for an Awesome Web App

First impression is the last impression. This statement is absolutely correct when we talk about web design and development. In this blog, let us talk about the tips for a great web web app.

Web application development has come a long way since the beginning of the World Wide Web. The web environment today uses HTML and CSS to view data and content to users while JavaScript is used to interact with the client.

Did you know that when a visitor arrives on your website, you have about five seconds (or less) to capture their attention and keep them where they are? That’s not a whole lot of time to impress someone, so if your load time is not perfect or your site’s navigation is all over the place, you can say goodbye to your visitors.

Believe it or not, the rapidly changing world of technology is not helping with this, either. New trends can easily make your website outdated and render it all but useless, leaving you with fewer visitors than you started with.

So, now the below questions arise:

How are you supposed to fix this issue and keep your visitors?

How do you create a website that looks good, functions perfectly, and communicates your message clearly?

Developers and designers have various approaches to improve web design. Regardless of whether you have a perfect, smooth, and proficient site, that doesn’t mean it will suitable always.

You ought to consistently consider site improvement thoughts as time passes by.

Read the full blog here

Web design company in India

#web-design-tips #web-designing-tips #website-design-tips #website-designing-tips #web-development-tips

Arun A

1623668860

Blazor Rich Text Editor - Markdown Editor Component

Overview
The Blazor Rich Text Editor is a feature-rich WYSIWYG HTML editor and WYSIWYG Markdown editor. The Rich Text Editor is used to create blogs, forum posts, notes sections, support tickets (incidents), comment sections, messaging applications, and more. The control provides an efficient user interface for a better editing experience with mobile support. It has a variety of tools to edit and format rich content and returns valid HTML markup or Markdown (MD) content. It allows users to insert images, links, tables, and lists with modular architectures.

  • Edit WYSIWYG HTML and markdown content with a rich set of tools for modern web and mobile applications.
  • Easily incorporate into blogs editor, messages, HTML email composer, and discussion forum-like applications.
  • Make a floating toolbar or inline editor that allows you to select any editable element on the page and edit-in-place.

https://www.syncfusion.com/blazor-components/blazor-wysiwyg-rich-text-editor

#wysiwyg #editor #blazor rich text editor #web-development

The Best Way to Build a Chatbot in 2021

A useful tool several businesses implement for answering questions that potential customers may have is a chatbot. Many programming languages give web designers several ways on how to make a chatbot for their websites. They are capable of answering basic questions for visitors and offer innovation for businesses.

With the help of programming languages, it is possible to create a chatbot from the ground up to satisfy someone’s needs.

Plan Out the Chatbot’s Purpose

Before building a chatbot, it is ideal for web designers to determine how it will function on a website. Several chatbot duties center around fulfilling customers’ needs and questions or compiling and optimizing data via transactions.

Some benefits of implementing chatbots include:

  • Generating leads for marketing products and services
  • Improve work capacity when employees cannot answer questions or during non-business hours
  • Reducing errors while providing accurate information to customers or visitors
  • Meeting customer demands through instant communication
  • Alerting customers about their online transactions

Some programmers may choose to design a chatbox to function through predefined answers based on the questions customers may input or function by adapting and learning via human input.

#chatbots #latest news #the best way to build a chatbot in 2021 #build #build a chatbot #best way to build a chatbot

Riyad Amin

Riyad Amin

1571046022

Build Your Own Cryptocurrency Blockchain in Python

Cryptocurrency is a decentralized digital currency that uses encryption techniques to regulate the generation of currency units and to verify the transfer of funds. Anonymity, decentralization, and security are among its main features. Cryptocurrency is not regulated or tracked by any centralized authority, government, or bank.

Blockchain, a decentralized peer-to-peer (P2P) network, which is comprised of data blocks, is an integral part of cryptocurrency. These blocks chronologically store information about transactions and adhere to a protocol for inter-node communication and validating new blocks. The data recorded in blocks cannot be altered without the alteration of all subsequent blocks.

In this article, we are going to explain how you can create a simple blockchain using the Python programming language.

Here is the basic blueprint of the Python class we’ll use for creating the blockchain:

class Block(object):
    def __init__():
        pass
    #initial structure of the block class 
    def compute_hash():
        pass
    #producing the cryptographic hash of each block 
  class BlockChain(object):
    def __init__(self):
    #building the chain
    def build_genesis(self):
        pass
    #creating the initial block
    def build_block(self, proof_number, previous_hash):
        pass
    #builds new block and adds to the chain
   @staticmethod
    def confirm_validity(block, previous_block):
        pass
    #checks whether the blockchain is valid
    def get_data(self, sender, receiver, amount):
        pass
    # declares data of transactions
    @staticmethod
    def proof_of_work(last_proof):
        pass
    #adds to the security of the blockchain
    @property
    def latest_block(self):
        pass
    #returns the last block in the chain

Now, let’s explain how the blockchain class works.

Initial Structure of the Block Class

Here is the code for our initial block class:

import hashlib
import time
class Block(object):
    def __init__(self, index, proof_number, previous_hash, data, timestamp=None):
        self.index = index
        self.proof_number = proof_number
        self.previous_hash = previous_hash
        self.data = data
        self.timestamp = timestamp or time.time()
    @property
    def compute_hash(self):
        string_block = "{}{}{}{}{}".format(self.index, self.proof_number, self.previous_hash, self.data, self.timestamp)
        return hashlib.sha256(string_block.encode()).hexdigest()

As you can see above, the class constructor or initiation method ( init()) above takes the following parameters:

self — just like any other Python class, this parameter is used to refer to the class itself. Any variable associated with the class can be accessed using it.

index — it’s used to track the position of a block within the blockchain.

previous_hash — it used to reference the hash of the previous block within the blockchain.

data—it gives details of the transactions done, for example, the amount bought.

timestamp—it inserts a timestamp for all the transactions performed.

The second method in the class, compute_hash , is used to produce the cryptographic hash of each block based on the above values.

As you can see, we imported the SHA-256 algorithm into the cryptocurrency blockchain project to help in getting the hashes of the blocks.

Once the values have been placed inside the hashing module, the algorithm will return a 256-bit string denoting the contents of the block.

So, this is what gives the blockchain immutability. Since each block will be represented by a hash, which will be computed from the hash of the previous block, corrupting any block in the chain will make the other blocks have invalid hashes, resulting in breakage of the whole blockchain network.

Building the Chain

The whole concept of a blockchain is based on the fact that the blocks are “chained” to each other. Now, we’ll create a blockchain class that will play the critical role of managing the entire chain.

It will keep the transactions data and include other helper methods for completing various roles, such as adding new blocks.

Let’s talk about the helper methods.

Adding the Constructor Method

Here is the code:

class BlockChain(object):
    def __init__(self):
        self.chain = []
        self.current_data = []
        self.nodes = set()
        self.build_genesis()

The init() constructor method is what instantiates the blockchain.

Here are the roles of its attributes:

self.chain — this variable stores all the blocks.

self.current_data — this variable stores information about the transactions in the block.

self.build_genesis() — this method is used to create the initial block in the chain.

Building the Genesis Block

The build_genesis() method is used for creating the initial block in the chain, that is, a block without any predecessors. The genesis block is what represents the beginning of the blockchain.

To create it, we’ll call the build_block() method and give it some default values. The parameters proof_number and previous_hash are both given a value of zero, though you can give them any value you desire.

Here is the code:

def build_genesis(self):
        self.build_block(proof_number=0, previous_hash=0)
 def build_block(self, proof_number, previous_hash):
        block = Block(
            index=len(self.chain),
            proof_number=proof_number,
            previous_hash=previous_hash,
            data=self.current_data
        )
        self.current_data = []  
        self.chain.append(block)
        return block

Confirming Validity of the Blockchain

The confirm_validity method is critical in examining the integrity of the blockchain and making sure inconsistencies are lacking.

As explained earlier, hashes are pivotal for realizing the security of the cryptocurrency blockchain, because any slight alteration in an object will result in the creation of an entirely different hash.

Thus, the confirm_validity method utilizes a series of if statements to assess whether the hash of each block has been compromised.

Furthermore, it also compares the hash values of every two successive blocks to identify any anomalies. If the chain is working properly, it returns true; otherwise, it returns false.

Here is the code:

def confirm_validity(block, previous_block):
        if previous_block.index + 1 != block.index:
            return False
        elif previous_block.compute_hash != block.previous_hash:
            return False
        elif block.timestamp <= previous_block.timestamp:
            return False
        return True

Declaring Data of Transactions

The get_data method is important in declaring the data of transactions on a block. This method takes three parameters (sender’s information, receiver’s information, and amount) and adds the transaction data to the self.current_data list.

Here is the code:

def get_data(self, sender, receiver, amount):
        self.current_data.append({
            'sender': sender,
            'receiver': receiver,
            'amount': amount
        })
        return True

Effecting the Proof of Work

In blockchain technology, Proof of Work (PoW) refers to the complexity involved in mining or generating new blocks on the blockchain.

For example, the PoW can be implemented by identifying a number that solves a problem whenever a user completes some computing work. Anyone on the blockchain network should find the number complex to identify but easy to verify — this is the main concept of PoW.

This way, it discourages spamming and compromising the integrity of the network.

In this article, we’ll illustrate how to include a Proof of Work algorithm in a blockchain cryptocurrency project.

Finalizing With the Last Block

Finally, the latest_block() helper method is used for retrieving the last block on the network, which is actually the current block.

Here is the code:

def latest_block(self):
        return self.chain[-1]

Implementing Blockchain Mining

Now, this is the most exciting section!

Initially, the transactions are kept in a list of unverified transactions. Mining refers to the process of placing the unverified transactions in a block and solving the PoW problem. It can be referred to as the computing work involved in verifying the transactions.

If everything has been figured out correctly, a block is created or mined and joined together with the others in the blockchain. If users have successfully mined a block, they are often rewarded for using their computing resources to solve the PoW problem.

Here is the mining method in this simple cryptocurrency blockchain project:

def block_mining(self, details_miner):
            self.get_data(
            sender="0", #it implies that this node has created a new block
            receiver=details_miner,
            quantity=1, #creating a new block (or identifying the proof number) is awarded with 1
        )
        last_block = self.latest_block
        last_proof_number = last_block.proof_number
        proof_number = self.proof_of_work(last_proof_number)
        last_hash = last_block.compute_hash
        block = self.build_block(proof_number, last_hash)
        return vars(block)

Summary

Here is the whole code for our crypto blockchain class in Python:

import hashlib
import time
class Block(object):
    def __init__(self, index, proof_number, previous_hash, data, timestamp=None):
        self.index = index
        self.proof_number = proof_number
        self.previous_hash = previous_hash
        self.data = data
        self.timestamp = timestamp or time.time()
    @property
    def compute_hash(self):
        string_block = "{}{}{}{}{}".format(self.index, self.proof_number, self.previous_hash, self.data, self.timestamp)
        return hashlib.sha256(string_block.encode()).hexdigest()
    def __repr__(self):
        return "{} - {} - {} - {} - {}".format(self.index, self.proof_number, self.previous_hash, self.data, self.timestamp)
class BlockChain(object):
    def __init__(self):
        self.chain = []
        self.current_data = []
        self.nodes = set()
        self.build_genesis()
    def build_genesis(self):
        self.build_block(proof_number=0, previous_hash=0)
    def build_block(self, proof_number, previous_hash):
        block = Block(
            index=len(self.chain),
            proof_number=proof_number,
            previous_hash=previous_hash,
            data=self.current_data
        )
        self.current_data = []  
        self.chain.append(block)
        return block
    @staticmethod
    def confirm_validity(block, previous_block):
        if previous_block.index + 1 != block.index:
            return False
        elif previous_block.compute_hash != block.previous_hash:
            return False
        elif block.timestamp <= previous_block.timestamp:
            return False
        return True
    def get_data(self, sender, receiver, amount):
        self.current_data.append({
            'sender': sender,
            'receiver': receiver,
            'amount': amount
        })
        return True        
    @staticmethod
    def proof_of_work(last_proof):
        pass
    @property
    def latest_block(self):
        return self.chain[-1]
    def chain_validity(self):
        pass        
    def block_mining(self, details_miner):       
        self.get_data(
            sender="0", #it implies that this node has created a new block
            receiver=details_miner,
            quantity=1, #creating a new block (or identifying the proof number) is awared with 1
        )
        last_block = self.latest_block
        last_proof_number = last_block.proof_number
        proof_number = self.proof_of_work(last_proof_number)
        last_hash = last_block.compute_hash
        block = self.build_block(proof_number, last_hash)
        return vars(block)  
    def create_node(self, address):
        self.nodes.add(address)
        return True
    @staticmethod
    def get_block_object(block_data):        
        return Block(
            block_data['index'],
            block_data['proof_number'],
            block_data['previous_hash'],
            block_data['data'],
            timestamp=block_data['timestamp']
        )
blockchain = BlockChain()
print("GET READY MINING ABOUT TO START")
print(blockchain.chain)
last_block = blockchain.latest_block
last_proof_number = last_block.proof_number
proof_number = blockchain.proof_of_work(last_proof_number)
blockchain.get_data(
    sender="0", #this means that this node has constructed another block
    receiver="LiveEdu.tv", 
    amount=1, #building a new block (or figuring out the proof number) is awarded with 1
)
last_hash = last_block.compute_hash
block = blockchain.build_block(proof_number, last_hash)
print("WOW, MINING HAS BEEN SUCCESSFUL!")
print(blockchain.chain)

Now, let’s try to run our code to see if we can generate some digital coins…

Wow, it worked!

Conclusion

That is it!

We hope that this article has assisted you to understand the underlying technology that powers cryptocurrencies such as Bitcoin and Ethereum.

We just illustrated the basic ideas for making your feet wet in the innovative blockchain technology. The project above can still be enhanced by incorporating other features to make it more useful and robust.

Learn More

Thanks for reading !

Do you have any comments or questions? Please share them below.

#python #cryptocurrency