A Simple Blockchain Application for Data Verification.

Learn how to code a viable application for Ethereum in a handful of lines.

Introduction

In this article I’m going to describe the simplest blockchain application that I know, with code examples. This is useful for those starting in the blockchain space as well as a design pattern for more experienced architects.

Imagine the following use case. You have received a document that has passed through several hands and you want to make sure that it is authentic. The document might be the service book for a car that you are buying, or it might be a document asserting that the house that you are buying really belongs to the seller. It could be anything.

Digitally signing documents to ensure that they haven’t been tampered with is nothing new. You can take the contents of the document and produce a cryptographic signature with them, which is sent along with the document itself.

The receiver of the document can produce the signature again and verify that it matches with the one provided. A match means that the document hasn’t changed.

This is what you get with MD5 checksums and it is very convenient to use. Its weakness is that you need to receive the signature to verify the authenticity of the document. If someone gets in the middle and changes both the document and the signature you will be none the wiser.

Since getting data from individuals is not something that can be easily trusted, sometimes a third party steps in to provide a record keeping service for a profit. This profit motive is what keeps the record keeper honest.

Workable, but not a perfect solution. The record keeper will naturally work itself to a position of power and extract high rents with no competition. Even worse, if economic incentives change the record keeper might become corrupt. Who watches the watchmen?

What Blockchain can do for you

A blockchain datastore is decentralized, robust and immutable.

• Decentralized means that the datastore runs collectively on the hardware of several different people.
• Robust means that the datastore will continue running even if some of the participants leave or stop cooperating.
• Immutable means that once data is stored in a blockchain it cannot be altered.

Blockchain solves the document registry problem in an elegant way. Once we enter a signature in the blockchain registry we don’t need to fear that the signature will be altered to match a tampered document. To do that a majority of network participants would have to agree on the change which makes it hardly secret.

At the same time, there is no one in a position of power to extract rent for running the service. The network participants provide the service themselves.

In this context, a document can be any data set. The same pattern will work for attesting to the authenticity of any business transaction, IoT data set or user identity, among many others.

If I would be writing this in 2016 I could implement about a hundred lines of code, then a whitepaper with two dozen pages, and raise a few million in an ICO. The applications for this pattern are endless and lots of people did take the opportunity.

Nowadays, it is useful to know how to use this building block to design more complex solutions. All blockchain solutions rely on storing user generated data that can be trusted without depending on anyone.

Implementation

This time I didn’t code the contract from scratch. I’m trying to stop reinventing the wheel and blockchain registries have been implemented by the dozen. A quick google search took me to the GitHub repo that I’ll use to show how the pattern works. Even if it uses an old version of solidity it works just fine and you can test it (thanks Svetlin!).

The contract is very simple with only one relevant contract variable and two functions.

• A documents mapping links the hash calculated for a document with the block in which it was added.
• An add method takes a hash and stores it in the mapping.
• A verifiy method returns the timestamp for a hash.

pragma solidity ^0.4.18;
contract DocumentRegistry {
  mapping (string => uint256) documents;
  address contractOwner = msg.sender;

  function add(string hash) 
    public 
    returns (uint256 dateAdded) 
  {
    require (msg.sender == contractOwner);
    var timeAdded = block.timestamp;
    documents[hash] = timeAdded;
    return timeAdded;
  }

  function verify(string hash) 
    constant 
    public 
    returns (uint256 dateAdded) 
  {
    return documents[hash];
  }
}

The frontend allows you to upload a document with contract.add and calculates a signature as a sha256 of the document contents.

async function uploadDocument() {
  …
  let fileReader = new FileReader();
  fileReader.onload = function() {
    let documentHash = sha256(fileReader.result);
    …
    contract.add(documentHash, function(err, result) {…});
    …
  }
}

The frontend also allows you to upload a document with contract.verifyand if it was uploaded before it will tell you approximately when.

function verifyDocument() {
  …
  let fileReader = new FileReader();
  fileReader.onload = function() {
    let documentHash = sha256(fileReader.result);
    …
    contract.verify(documentHash, function(err, result) {
    …
    let contractPublishDate = result.toNumber();
    if (contractPublishDate > 0) {
      let displayDate = new Date(
        contractPublishDate * 1000
      ).toLocaleString();
      showInfo(
        `Document ${documentHash} is <b>valid<b>, 
        date published: ${displayDate}`
      );
    }
    else
      return showError(
        `Document ${documentHash} is <b>invalid</b>: 
        not found in the registry.`
      );
    });
  }
  …
}

That’s all that you need to implement a decentralized document registry that allows two things:

1. To sign a document
2. To verify if a document has changed since its last recorded signature.

This works because the chance of two different documents having the same signature is very close to zero. If you get a timestamp back you can be certain that the document that you are providing was introduced to the registry at that time.

The contract code can certainly be updated and improved, but the core behaviour in those 17 lines is still correct.

Conclusion

A document registry is the simplest implementation of a blockchain application with business value. In 2016 the few lines of code in this article would have been enough to raise several million dollars in an ICO. Today they are still relevant as one of the building blocks that you can reuse again and again in more complex solutions.

A document registry effectively uses the decentralization and immutability properties of blockchain to eliminate the need of trusting anyone that the data provided is genuine. The idea is simple but revolutionary.

#web-development #blockchain

What is GEEK

Buddha Community

Your Data Architecture: Simple Best Practices for Your Data Strategy

If you accumulate data on which you base your decision-making as an organization, you should probably think about your data architecture and possible best practices.

If you accumulate data on which you base your decision-making as an organization, you most probably need to think about your data architecture and consider possible best practices. Gaining a competitive edge, remaining customer-centric to the greatest extent possible, and streamlining processes to get on-the-button outcomes can all be traced back to an organization’s capacity to build a future-ready data architecture.

In what follows, we offer a short overview of the overarching capabilities of data architecture. These include user-centricity, elasticity, robustness, and the capacity to ensure the seamless flow of data at all times. Added to these are automation enablement, plus security and data governance considerations. These points from our checklist for what we perceive to be an anticipatory analytics ecosystem.

#big data #data science #big data analytics #data analysis #data architecture #data transformation #data platform #data strategy #cloud data platform #data acquisition

使用 jQuery 创建分页

在本文中，我们将看到如何使用 jquery 创建分页。我们将使用多种方式创建 jquery 分页。您可以使用不同的方式创建分页，例如使用简单的 HTML 创建分页，您可以使用 paginate() 方法在 laravel 中创建分页。另外，创建分页 laravel livewire，使用 bootstrap 进行分页。

我们将创建简单的 jquery 分页。此外，使用不带插件的 jquery 创建分页，并使用下一个和上一个按钮创建 jquery 分页

那么，让我们看看jquery中的动态分页和jquery中的bootstrap分页

例子：

在这个例子中，我们将使用 jquery 创建分页而不使用插件。此外，您可以自定义分页。

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>How To Create Pagination Using jQuery - Websolutionstuff</title>
        <style>
            .current {
            color: green;
            }

            #pagin li {
            display: inline-block;
            font-weight: 500;
            }

            .prev {
            cursor: pointer;
            }

            .next {
            cursor: pointer;
            }

            .last {
            cursor:pointer;
            margin-left:10px;
            }

            .first {
            cursor:pointer;
            margin-right:10px;
            }

            .line-content, #pagin, h3 {
            text-align:center;
            }

            .line-content {
            margin-top:20px;
            }

            #pagin {
            margin-top:10px;
            padding-left:0;
            }

            h3 {
            margin:50px 0;  
            }
        </style>
    </head>
    <body>
        <h3>How To Create Pagination Using jQuery - Websolutionstuff</h3>
        <div class="line-content">This is Page 1 content example with next and prev.</div>
        <div class="line-content">This is Page 2 content example with next and prev.</div>
        <div class="line-content">This is Page 3 content example with next and prev.</div>
        <div class="line-content">This is Page 4 content example with next and prev.</div>
        <div class="line-content">This is Page 5 content example with next and prev.</div>
        <div class="line-content">This is Page 6 content example with next and prev.</div>
        <div class="line-content">This is Page 7 content example with next and prev.</div>
        <div class="line-content">This is Page 8 content example with next and prev.</div>
        <div class="line-content">This is Page 9 content example with next and prev.</div>
        <div class="line-content">This is Page 10 content example with next and prev.</div>
        <div class="line-content">This is Page 11 content example with next and prev.</div>
        <div class="line-content">This is Page 12 content example with next and prev.</div>
        <div class="line-content">This is Page 13 content example with next and prev.</div>
        <div class="line-content">This is Page 14 content example with next and prev.</div>
        <div class="line-content">This is Page 15 content example with next and prev.</div>
        <div class="line-content">This is Page 16 content example with next and prev.</div>
        <div class="line-content">This is Page 17 content example with next and prev.</div>
        <div class="line-content">This is Page 18 content example with next and prev.</div>
        <div class="line-content">This is Page 19 content example with next and prev.</div>
        <div class="line-content">This is Page 20 content example with next and prev.</div>
        <div class="line-content">This is Page 21 content example with next and prev.</div>
        <div class="line-content">This is Page 22 content example with next and prev.</div>
        <div class="line-content">This is Page 23 content example with next and prev.</div>
        <div class="line-content">This is Page 24 content example with next and prev.</div>
        <div class="line-content">This is Page 25 content example with next and prev.</div>
        <div class="line-content">This is Page 26 content example with next and prev.</div>
        <div class="line-content">This is Page 27 content example with next and prev.</div>
        <div class="line-content">This is Page 28 content example with next and prev.</div>
        <div class="line-content">This is Page 29 content example with next and prev.</div>
        <div class="line-content">This is Page 30 content example with next and prev.</div>
        <div class="line-content">This is Page 31 content example with next and prev.</div>
        <div class="line-content">This is Page 32 content example with next and prev.</div>
        <div class="line-content">This is Page 33 content example with next and prev.</div>
        <div class="line-content">This is Page 34 content example with next and prev.</div>
        <div class="line-content">This is Page 35 content example with next and prev.</div>
        <div class="line-content">This is Page 36 content example with next and prev.</div>
        <div class="line-content">This is Page 37 content example with next and prev.</div>
        <div class="line-content">This is Page 38 content example with next and prev.</div>
        <div class="line-content">This is Page 39 content example with next and prev.</div>
        <div class="line-content">This is Page 40 content example with next and prev.</div>
        <div class="line-content">This is Page 41 content example with next and prev.</div>
        <div class="line-content">This is Page 42 content example with next and prev.</div>
        <div class="line-content">This is Page 43 content example with next and prev.</div>
        <div class="line-content">This is Page 44 content example with next and prev.</div>
        <div class="line-content">This is Page 45 content example with next and prev.</div>
        <ul id="pagin"></ul>
    </body>
</html>
<script src="https://code.jquery.com/jquery-3.6.1.min.js" integrity="sha256-o88AwQnZB+VDvE9tvIXrMQaPlFFSUTR+nldQm1LuPXQ=" crossorigin="anonymous"></script>
<script>

pageSize = 5;
incremSlide = 5;
startPage = 0;
numberPage = 0;

var pageCount =  $(".line-content").length / pageSize;
var totalSlidepPage = Math.floor(pageCount / incremSlide);
    
for(var i = 0 ; i<pageCount;i++){
    $("#pagin").append('<li><a href="#">'+(i+1)+'</a></li> ');
    if(i>pageSize){
       $("#pagin li").eq(i).hide();
    }
}

var prev = $("<li/>").addClass("prev").html("Prev").click(function(){
    startPage-=5;
    incremSlide-=5;
    numberPage--;
    slide();
});

prev.hide();

var next = $("<li/>").addClass("next").html("Next").click(function(){
    startPage+=5;
    incremSlide+=5;
    numberPage++;
    slide();
});

$("#pagin").prepend(prev).append(next);

$("#pagin li").first().find("a").addClass("current");

slide = function(sens){
    $("#pagin li").hide();
   
    for(t=startPage;t<incremSlide;t++){
        $("#pagin li").eq(t+1).show();
    }
    if(startPage == 0){
        next.show();
        prev.hide();
    }else if(numberPage == totalSlidepPage ){
        next.hide();
        prev.show();
    }else{
        next.show();
        prev.show();
    }    
}

showPage = function(page) {
    $(".line-content").hide();
    $(".line-content").each(function(n) {
        if (n >= pageSize * (page - 1) && n < pageSize * page){
            $(this).show();
        }
    });        
}
    
showPage(1);
$("#pagin li a").eq(0).addClass("current");

$("#pagin li a").click(function() {
    $("#pagin li a").removeClass("current");
    $(this).addClass("current");
    showPage(parseInt($(this).text()));
});
</script>

输出：

例子：

在这个例子中，我们将在 jquery 的帮助下创建引导分页。

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>How To Create Bootstrap Pagination Using jQuery - Websolutionstuff</title>
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
        <style>
            #data tr {
                display: none;
            }

            .page {
                margin: 30px;
            }

            table, th, td {
                border: 1px solid black;
            }

            #data {
                font-family: Arial, Helvetica, sans-serif;
                border-collapse: collapse;
                width: 100%;
            }

            #data td, #data th {
                border: 1px solid #ddd;
                padding: 8px;
            }

            #data tr:nth-child(even) {
                background-color: #f2f2f2;
            }

            #data tr:hover {
                background-color: #ddd;
            }

            #data th {
                padding-top: 12px;
                padding-bottom: 12px;
                text-align: left;
                background-color: #03aa96;
                color: white;
            }

            #nav a {
                color: #03aa96;
                font-size: 20px;
                margin-top: 22px;
                font-weight: 600;
            }

            a:hover, a:visited, a:link, a:active {
                text-decoration: none;
            }

            #nav {
                margin-top: 20px;
            }
        </style>
    </head>
    <body>                  
        <h2 align="center" class="mt-4">How To Create Bootstrap Pagination Using jQuery - Websolutionstuff</h2>
        <div class="page" align="center">   
            <table id="data">  
                <tr>  
                    <th>Id</th>  
                    <th>Name</th>  
                    <th>Country</th>  
                </tr>  
                <tr>  
                    <td>1</td>  
                    <td>Maria</td>  
                    <td>Germany</td>  
                </tr>  
                <tr>  
                    <td>2</td>  
                    <td>Christina</td>  
                    <td>Sweden</td>  
                </tr>  
                <tr>  
                    <td>3</td>  
                    <td>Chang</td>  
                    <td>Mexico</td>  
                </tr>  
                <tr>  
                    <td>4</td>  
                    <td>Mendel</td>  
                    <td>Austria</td>  
                </tr>  
                <tr>  
                    <td>5</td>  
                    <td>Helen</td>  
                    <td>United Kingdom</td>  
                </tr>  
                <tr>  
                    <td>6</td>  
                    <td>Philip</td>  
                    <td>Germany</td>  
                </tr>  
                <tr>  
                    <td>7</td>  
                    <td>Tannamuri</td>  
                    <td>Canada</td>  
                </tr>  
                <tr>  
                    <td>8</td>  
                    <td>Rovelli</td>  
                    <td>Italy</td>  
                </tr>  
                <tr>  
                    <td>9</td>  
                    <td>Dell</td>
                    <td>United Kingdom</td>
                </tr>  
                <tr>  
                    <td>10</td>  
                    <td>Trump</td>  
                    <td>France</td>  
                </tr>  
            </table>  
        </div>
    </body>
</html>
<script src="https://code.jquery.com/jquery-3.6.1.min.js" integrity="sha256-o88AwQnZB+VDvE9tvIXrMQaPlFFSUTR+nldQm1LuPXQ=" crossorigin="anonymous"></script>
<script>
$(document).ready (function () {  
    $('#data').after ('<div id="nav"></div>');  
    var rowsShown = 5;  
    var rowsTotal = $('#data tbody tr').length;  
    var numPages = rowsTotal/rowsShown;  
    for (i = 0;i < numPages;i++) {  
        var pageNum = i + 1;  
        $('#nav').append ('<a href="#" rel="'+i+'">'+pageNum+'</a> ');  
    }  
    $('#data tbody tr').hide();  
    $('#data tbody tr').slice (0, rowsShown).show();  
    $('#nav a:first').addClass('active');  
    $('#nav a').bind('click', function() {  
    $('#nav a').removeClass('active');  
    $(this).addClass('active');  
        var currPage = $(this).attr('rel');  
        var startItem = currPage * rowsShown;  
        var endItem = startItem + rowsShown;  
        $('#data tbody tr').css('opacity','0.0').hide().slice(startItem, endItem).  
        css('display','table-row').animate({opacity:1}, 300);  
    });  
});
</script>

输出：

例子：

在此示例中，我们将使用twbsPagination插件创建分页。这个 jQuery 插件简化了 Bootstrap 分页的使用。

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>jQuery Pagination Using Plugin - Websolutionstuff</title>
        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.6/css/bootstrap.min.css">
        <style>
            .wrapper{
                margin: 60px auto;
                text-align: center;
            }
            h2{
                margin-bottom: 1.25em;
            }
            
            #pagination-demo{
                display: inline-block;
                margin-bottom: 1.75em;
            }

            #pagination-demo li{
                display: inline-block;
            }

            .page-content{
                background: #eee;
                display: inline-block;
                padding: 10px;
                width: 100%;
                max-width: 660px;
            }
        </style>
    </head>
    <body>                  
        <div class="wrapper">
            <div class="container">
              
              <div class="row">
                <div class="col-sm-12">
                  <h2>jQuery Pagination Using Plugin - Websolutionstuff</h2>
                  <p>Simple pagination using the TWBS pagination JS library.</p>
                  <ul id="pagination-demo" class="pagination-sm"></ul>
                </div>
              </div>
          
              <div id="page-content" class="page-content">Page 1</div>
            </div>
          </div>
    </body>
</html>
<script src="https://code.jquery.com/jquery-3.6.1.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.6/js/bootstrap.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twbs-pagination/1.4.1/jquery.twbsPagination.min.js"></script>
<script>
$(document).ready (function () {  
    $('#pagination-demo').twbsPagination({
        totalPages: 16,
        visiblePages: 6,
        next: 'Next',
        prev: 'Prev',
        onPageClick: function (event, page) {            
            $('#page-content').text('Page ' + page) + ' content here';
        }
    });
});
</script>

输出：

原文出处：https: //websolutionstuff.com/

#jquery #pagination 

Create Pagination Using jQuery

In this article, we will see how to create pagination using jquery. We will create jquery pagination using multiple ways. You can create pagination using different ways like creating pagination using simple HTML, you can create pagination in laravel using paginate() method. Also, create pagination laravel livewire, pagination using bootstrap.

We will create simple jquery pagination. Also, create pagination using jquery without a plugin and create jquery pagination with next and previous buttons

So, let's see dynamic pagination in jquery and bootstrap pagination in jquery

Example:

In this example, we will create pagination using jquery without using a plugin. Also, you can customize the pagination.

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>How To Create Pagination Using jQuery - Websolutionstuff</title>
        <style>
            .current {
            color: green;
            }

            #pagin li {
            display: inline-block;
            font-weight: 500;
            }

            .prev {
            cursor: pointer;
            }

            .next {
            cursor: pointer;
            }

            .last {
            cursor:pointer;
            margin-left:10px;
            }

            .first {
            cursor:pointer;
            margin-right:10px;
            }

            .line-content, #pagin, h3 {
            text-align:center;
            }

            .line-content {
            margin-top:20px;
            }

            #pagin {
            margin-top:10px;
            padding-left:0;
            }

            h3 {
            margin:50px 0;  
            }
        </style>
    </head>
    <body>
        <h3>How To Create Pagination Using jQuery - Websolutionstuff</h3>
        <div class="line-content">This is Page 1 content example with next and prev.</div>
        <div class="line-content">This is Page 2 content example with next and prev.</div>
        <div class="line-content">This is Page 3 content example with next and prev.</div>
        <div class="line-content">This is Page 4 content example with next and prev.</div>
        <div class="line-content">This is Page 5 content example with next and prev.</div>
        <div class="line-content">This is Page 6 content example with next and prev.</div>
        <div class="line-content">This is Page 7 content example with next and prev.</div>
        <div class="line-content">This is Page 8 content example with next and prev.</div>
        <div class="line-content">This is Page 9 content example with next and prev.</div>
        <div class="line-content">This is Page 10 content example with next and prev.</div>
        <div class="line-content">This is Page 11 content example with next and prev.</div>
        <div class="line-content">This is Page 12 content example with next and prev.</div>
        <div class="line-content">This is Page 13 content example with next and prev.</div>
        <div class="line-content">This is Page 14 content example with next and prev.</div>
        <div class="line-content">This is Page 15 content example with next and prev.</div>
        <div class="line-content">This is Page 16 content example with next and prev.</div>
        <div class="line-content">This is Page 17 content example with next and prev.</div>
        <div class="line-content">This is Page 18 content example with next and prev.</div>
        <div class="line-content">This is Page 19 content example with next and prev.</div>
        <div class="line-content">This is Page 20 content example with next and prev.</div>
        <div class="line-content">This is Page 21 content example with next and prev.</div>
        <div class="line-content">This is Page 22 content example with next and prev.</div>
        <div class="line-content">This is Page 23 content example with next and prev.</div>
        <div class="line-content">This is Page 24 content example with next and prev.</div>
        <div class="line-content">This is Page 25 content example with next and prev.</div>
        <div class="line-content">This is Page 26 content example with next and prev.</div>
        <div class="line-content">This is Page 27 content example with next and prev.</div>
        <div class="line-content">This is Page 28 content example with next and prev.</div>
        <div class="line-content">This is Page 29 content example with next and prev.</div>
        <div class="line-content">This is Page 30 content example with next and prev.</div>
        <div class="line-content">This is Page 31 content example with next and prev.</div>
        <div class="line-content">This is Page 32 content example with next and prev.</div>
        <div class="line-content">This is Page 33 content example with next and prev.</div>
        <div class="line-content">This is Page 34 content example with next and prev.</div>
        <div class="line-content">This is Page 35 content example with next and prev.</div>
        <div class="line-content">This is Page 36 content example with next and prev.</div>
        <div class="line-content">This is Page 37 content example with next and prev.</div>
        <div class="line-content">This is Page 38 content example with next and prev.</div>
        <div class="line-content">This is Page 39 content example with next and prev.</div>
        <div class="line-content">This is Page 40 content example with next and prev.</div>
        <div class="line-content">This is Page 41 content example with next and prev.</div>
        <div class="line-content">This is Page 42 content example with next and prev.</div>
        <div class="line-content">This is Page 43 content example with next and prev.</div>
        <div class="line-content">This is Page 44 content example with next and prev.</div>
        <div class="line-content">This is Page 45 content example with next and prev.</div>
        <ul id="pagin"></ul>
    </body>
</html>
<script src="https://code.jquery.com/jquery-3.6.1.min.js" integrity="sha256-o88AwQnZB+VDvE9tvIXrMQaPlFFSUTR+nldQm1LuPXQ=" crossorigin="anonymous"></script>
<script>

pageSize = 5;
incremSlide = 5;
startPage = 0;
numberPage = 0;

var pageCount =  $(".line-content").length / pageSize;
var totalSlidepPage = Math.floor(pageCount / incremSlide);
    
for(var i = 0 ; i<pageCount;i++){
    $("#pagin").append('<li><a href="#">'+(i+1)+'</a></li> ');
    if(i>pageSize){
       $("#pagin li").eq(i).hide();
    }
}

var prev = $("<li/>").addClass("prev").html("Prev").click(function(){
    startPage-=5;
    incremSlide-=5;
    numberPage--;
    slide();
});

prev.hide();

var next = $("<li/>").addClass("next").html("Next").click(function(){
    startPage+=5;
    incremSlide+=5;
    numberPage++;
    slide();
});

$("#pagin").prepend(prev).append(next);

$("#pagin li").first().find("a").addClass("current");

slide = function(sens){
    $("#pagin li").hide();
   
    for(t=startPage;t<incremSlide;t++){
        $("#pagin li").eq(t+1).show();
    }
    if(startPage == 0){
        next.show();
        prev.hide();
    }else if(numberPage == totalSlidepPage ){
        next.hide();
        prev.show();
    }else{
        next.show();
        prev.show();
    }    
}

showPage = function(page) {
    $(".line-content").hide();
    $(".line-content").each(function(n) {
        if (n >= pageSize * (page - 1) && n < pageSize * page){
            $(this).show();
        }
    });        
}
    
showPage(1);
$("#pagin li a").eq(0).addClass("current");

$("#pagin li a").click(function() {
    $("#pagin li a").removeClass("current");
    $(this).addClass("current");
    showPage(parseInt($(this).text()));
});
</script>

Output:

Example:

In this example, we will create bootstrap pagination with help of jquery.

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>How To Create Bootstrap Pagination Using jQuery - Websolutionstuff</title>
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
        <style>
            #data tr {
                display: none;
            }

            .page {
                margin: 30px;
            }

            table, th, td {
                border: 1px solid black;
            }

            #data {
                font-family: Arial, Helvetica, sans-serif;
                border-collapse: collapse;
                width: 100%;
            }

            #data td, #data th {
                border: 1px solid #ddd;
                padding: 8px;
            }

            #data tr:nth-child(even) {
                background-color: #f2f2f2;
            }

            #data tr:hover {
                background-color: #ddd;
            }

            #data th {
                padding-top: 12px;
                padding-bottom: 12px;
                text-align: left;
                background-color: #03aa96;
                color: white;
            }

            #nav a {
                color: #03aa96;
                font-size: 20px;
                margin-top: 22px;
                font-weight: 600;
            }

            a:hover, a:visited, a:link, a:active {
                text-decoration: none;
            }

            #nav {
                margin-top: 20px;
            }
        </style>
    </head>
    <body>                  
        <h2 align="center" class="mt-4">How To Create Bootstrap Pagination Using jQuery - Websolutionstuff</h2>
        <div class="page" align="center">   
            <table id="data">  
                <tr>  
                    <th>Id</th>  
                    <th>Name</th>  
                    <th>Country</th>  
                </tr>  
                <tr>  
                    <td>1</td>  
                    <td>Maria</td>  
                    <td>Germany</td>  
                </tr>  
                <tr>  
                    <td>2</td>  
                    <td>Christina</td>  
                    <td>Sweden</td>  
                </tr>  
                <tr>  
                    <td>3</td>  
                    <td>Chang</td>  
                    <td>Mexico</td>  
                </tr>  
                <tr>  
                    <td>4</td>  
                    <td>Mendel</td>  
                    <td>Austria</td>  
                </tr>  
                <tr>  
                    <td>5</td>  
                    <td>Helen</td>  
                    <td>United Kingdom</td>  
                </tr>  
                <tr>  
                    <td>6</td>  
                    <td>Philip</td>  
                    <td>Germany</td>  
                </tr>  
                <tr>  
                    <td>7</td>  
                    <td>Tannamuri</td>  
                    <td>Canada</td>  
                </tr>  
                <tr>  
                    <td>8</td>  
                    <td>Rovelli</td>  
                    <td>Italy</td>  
                </tr>  
                <tr>  
                    <td>9</td>  
                    <td>Dell</td>
                    <td>United Kingdom</td>
                </tr>  
                <tr>  
                    <td>10</td>  
                    <td>Trump</td>  
                    <td>France</td>  
                </tr>  
            </table>  
        </div>
    </body>
</html>
<script src="https://code.jquery.com/jquery-3.6.1.min.js" integrity="sha256-o88AwQnZB+VDvE9tvIXrMQaPlFFSUTR+nldQm1LuPXQ=" crossorigin="anonymous"></script>
<script>
$(document).ready (function () {  
    $('#data').after ('<div id="nav"></div>');  
    var rowsShown = 5;  
    var rowsTotal = $('#data tbody tr').length;  
    var numPages = rowsTotal/rowsShown;  
    for (i = 0;i < numPages;i++) {  
        var pageNum = i + 1;  
        $('#nav').append ('<a href="#" rel="'+i+'">'+pageNum+'</a> ');  
    }  
    $('#data tbody tr').hide();  
    $('#data tbody tr').slice (0, rowsShown).show();  
    $('#nav a:first').addClass('active');  
    $('#nav a').bind('click', function() {  
    $('#nav a').removeClass('active');  
    $(this).addClass('active');  
        var currPage = $(this).attr('rel');  
        var startItem = currPage * rowsShown;  
        var endItem = startItem + rowsShown;  
        $('#data tbody tr').css('opacity','0.0').hide().slice(startItem, endItem).  
        css('display','table-row').animate({opacity:1}, 300);  
    });  
});
</script>

Output:

Example:

In this example, we will create pagination using the twbsPagination plugin. This jQuery plugin simplifies the usage of Bootstrap Pagination.

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>jQuery Pagination Using Plugin - Websolutionstuff</title>
        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.6/css/bootstrap.min.css">
        <style>
            .wrapper{
                margin: 60px auto;
                text-align: center;
            }
            h2{
                margin-bottom: 1.25em;
            }
            
            #pagination-demo{
                display: inline-block;
                margin-bottom: 1.75em;
            }

            #pagination-demo li{
                display: inline-block;
            }

            .page-content{
                background: #eee;
                display: inline-block;
                padding: 10px;
                width: 100%;
                max-width: 660px;
            }
        </style>
    </head>
    <body>                  
        <div class="wrapper">
            <div class="container">
              
              <div class="row">
                <div class="col-sm-12">
                  <h2>jQuery Pagination Using Plugin - Websolutionstuff</h2>
                  <p>Simple pagination using the TWBS pagination JS library.</p>
                  <ul id="pagination-demo" class="pagination-sm"></ul>
                </div>
              </div>
          
              <div id="page-content" class="page-content">Page 1</div>
            </div>
          </div>
    </body>
</html>
<script src="https://code.jquery.com/jquery-3.6.1.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.6/js/bootstrap.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twbs-pagination/1.4.1/jquery.twbsPagination.min.js"></script>
<script>
$(document).ready (function () {  
    $('#pagination-demo').twbsPagination({
        totalPages: 16,
        visiblePages: 6,
        next: 'Next',
        prev: 'Prev',
        onPageClick: function (event, page) {            
            $('#page-content').text('Page ' + page) + ' content here';
        }
    });
});
</script>

Output:

Original article source at: https://websolutionstuff.com/

#jquery #pagination 

Создание пагинации с помощью jQuery

В этой статье мы увидим, как создать пагинацию с помощью jquery. Мы создадим разбиение на страницы jquery, используя несколько способов. Вы можете создать разбиение на страницы, используя разные способы, такие как создание разбиения на страницы с помощью простого HTML, вы можете создать разбиение на страницы в laravel, используя метод paginate(). Кроме того, создайте разбиение на страницы laravel livewire, разбиение на страницы с помощью бутстрапа.

Мы создадим простую пагинацию jquery. Кроме того, создайте разбиение на страницы с помощью jquery без плагина и создайте разбивку на страницы jquery с помощью кнопок «Далее» и «Предыдущий».

Итак, давайте посмотрим динамическую нумерацию страниц в jquery и бутстраповскую нумерацию страниц в jquery.

Пример:

В этом примере мы создадим пагинацию с помощью jquery без использования плагина. Кроме того, вы можете настроить пагинацию.

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>How To Create Pagination Using jQuery - Websolutionstuff</title>
        <style>
            .current {
            color: green;
            }

            #pagin li {
            display: inline-block;
            font-weight: 500;
            }

            .prev {
            cursor: pointer;
            }

            .next {
            cursor: pointer;
            }

            .last {
            cursor:pointer;
            margin-left:10px;
            }

            .first {
            cursor:pointer;
            margin-right:10px;
            }

            .line-content, #pagin, h3 {
            text-align:center;
            }

            .line-content {
            margin-top:20px;
            }

            #pagin {
            margin-top:10px;
            padding-left:0;
            }

            h3 {
            margin:50px 0;  
            }
        </style>
    </head>
    <body>
        <h3>How To Create Pagination Using jQuery - Websolutionstuff</h3>
        <div class="line-content">This is Page 1 content example with next and prev.</div>
        <div class="line-content">This is Page 2 content example with next and prev.</div>
        <div class="line-content">This is Page 3 content example with next and prev.</div>
        <div class="line-content">This is Page 4 content example with next and prev.</div>
        <div class="line-content">This is Page 5 content example with next and prev.</div>
        <div class="line-content">This is Page 6 content example with next and prev.</div>
        <div class="line-content">This is Page 7 content example with next and prev.</div>
        <div class="line-content">This is Page 8 content example with next and prev.</div>
        <div class="line-content">This is Page 9 content example with next and prev.</div>
        <div class="line-content">This is Page 10 content example with next and prev.</div>
        <div class="line-content">This is Page 11 content example with next and prev.</div>
        <div class="line-content">This is Page 12 content example with next and prev.</div>
        <div class="line-content">This is Page 13 content example with next and prev.</div>
        <div class="line-content">This is Page 14 content example with next and prev.</div>
        <div class="line-content">This is Page 15 content example with next and prev.</div>
        <div class="line-content">This is Page 16 content example with next and prev.</div>
        <div class="line-content">This is Page 17 content example with next and prev.</div>
        <div class="line-content">This is Page 18 content example with next and prev.</div>
        <div class="line-content">This is Page 19 content example with next and prev.</div>
        <div class="line-content">This is Page 20 content example with next and prev.</div>
        <div class="line-content">This is Page 21 content example with next and prev.</div>
        <div class="line-content">This is Page 22 content example with next and prev.</div>
        <div class="line-content">This is Page 23 content example with next and prev.</div>
        <div class="line-content">This is Page 24 content example with next and prev.</div>
        <div class="line-content">This is Page 25 content example with next and prev.</div>
        <div class="line-content">This is Page 26 content example with next and prev.</div>
        <div class="line-content">This is Page 27 content example with next and prev.</div>
        <div class="line-content">This is Page 28 content example with next and prev.</div>
        <div class="line-content">This is Page 29 content example with next and prev.</div>
        <div class="line-content">This is Page 30 content example with next and prev.</div>
        <div class="line-content">This is Page 31 content example with next and prev.</div>
        <div class="line-content">This is Page 32 content example with next and prev.</div>
        <div class="line-content">This is Page 33 content example with next and prev.</div>
        <div class="line-content">This is Page 34 content example with next and prev.</div>
        <div class="line-content">This is Page 35 content example with next and prev.</div>
        <div class="line-content">This is Page 36 content example with next and prev.</div>
        <div class="line-content">This is Page 37 content example with next and prev.</div>
        <div class="line-content">This is Page 38 content example with next and prev.</div>
        <div class="line-content">This is Page 39 content example with next and prev.</div>
        <div class="line-content">This is Page 40 content example with next and prev.</div>
        <div class="line-content">This is Page 41 content example with next and prev.</div>
        <div class="line-content">This is Page 42 content example with next and prev.</div>
        <div class="line-content">This is Page 43 content example with next and prev.</div>
        <div class="line-content">This is Page 44 content example with next and prev.</div>
        <div class="line-content">This is Page 45 content example with next and prev.</div>
        <ul id="pagin"></ul>
    </body>
</html>
<script src="https://code.jquery.com/jquery-3.6.1.min.js" integrity="sha256-o88AwQnZB+VDvE9tvIXrMQaPlFFSUTR+nldQm1LuPXQ=" crossorigin="anonymous"></script>
<script>

pageSize = 5;
incremSlide = 5;
startPage = 0;
numberPage = 0;

var pageCount =  $(".line-content").length / pageSize;
var totalSlidepPage = Math.floor(pageCount / incremSlide);
    
for(var i = 0 ; i<pageCount;i++){
    $("#pagin").append('<li><a href="#">'+(i+1)+'</a></li> ');
    if(i>pageSize){
       $("#pagin li").eq(i).hide();
    }
}

var prev = $("<li/>").addClass("prev").html("Prev").click(function(){
    startPage-=5;
    incremSlide-=5;
    numberPage--;
    slide();
});

prev.hide();

var next = $("<li/>").addClass("next").html("Next").click(function(){
    startPage+=5;
    incremSlide+=5;
    numberPage++;
    slide();
});

$("#pagin").prepend(prev).append(next);

$("#pagin li").first().find("a").addClass("current");

slide = function(sens){
    $("#pagin li").hide();
   
    for(t=startPage;t<incremSlide;t++){
        $("#pagin li").eq(t+1).show();
    }
    if(startPage == 0){
        next.show();
        prev.hide();
    }else if(numberPage == totalSlidepPage ){
        next.hide();
        prev.show();
    }else{
        next.show();
        prev.show();
    }    
}

showPage = function(page) {
    $(".line-content").hide();
    $(".line-content").each(function(n) {
        if (n >= pageSize * (page - 1) && n < pageSize * page){
            $(this).show();
        }
    });        
}
    
showPage(1);
$("#pagin li a").eq(0).addClass("current");

$("#pagin li a").click(function() {
    $("#pagin li a").removeClass("current");
    $(this).addClass("current");
    showPage(parseInt($(this).text()));
});
</script>

Выход:

Пример:

В этом примере мы создадим загрузочную пагинацию с помощью jquery.

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>How To Create Bootstrap Pagination Using jQuery - Websolutionstuff</title>
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
        <style>
            #data tr {
                display: none;
            }

            .page {
                margin: 30px;
            }

            table, th, td {
                border: 1px solid black;
            }

            #data {
                font-family: Arial, Helvetica, sans-serif;
                border-collapse: collapse;
                width: 100%;
            }

            #data td, #data th {
                border: 1px solid #ddd;
                padding: 8px;
            }

            #data tr:nth-child(even) {
                background-color: #f2f2f2;
            }

            #data tr:hover {
                background-color: #ddd;
            }

            #data th {
                padding-top: 12px;
                padding-bottom: 12px;
                text-align: left;
                background-color: #03aa96;
                color: white;
            }

            #nav a {
                color: #03aa96;
                font-size: 20px;
                margin-top: 22px;
                font-weight: 600;
            }

            a:hover, a:visited, a:link, a:active {
                text-decoration: none;
            }

            #nav {
                margin-top: 20px;
            }
        </style>
    </head>
    <body>                  
        <h2 align="center" class="mt-4">How To Create Bootstrap Pagination Using jQuery - Websolutionstuff</h2>
        <div class="page" align="center">   
            <table id="data">  
                <tr>  
                    <th>Id</th>  
                    <th>Name</th>  
                    <th>Country</th>  
                </tr>  
                <tr>  
                    <td>1</td>  
                    <td>Maria</td>  
                    <td>Germany</td>  
                </tr>  
                <tr>  
                    <td>2</td>  
                    <td>Christina</td>  
                    <td>Sweden</td>  
                </tr>  
                <tr>  
                    <td>3</td>  
                    <td>Chang</td>  
                    <td>Mexico</td>  
                </tr>  
                <tr>  
                    <td>4</td>  
                    <td>Mendel</td>  
                    <td>Austria</td>  
                </tr>  
                <tr>  
                    <td>5</td>  
                    <td>Helen</td>  
                    <td>United Kingdom</td>  
                </tr>  
                <tr>  
                    <td>6</td>  
                    <td>Philip</td>  
                    <td>Germany</td>  
                </tr>  
                <tr>  
                    <td>7</td>  
                    <td>Tannamuri</td>  
                    <td>Canada</td>  
                </tr>  
                <tr>  
                    <td>8</td>  
                    <td>Rovelli</td>  
                    <td>Italy</td>  
                </tr>  
                <tr>  
                    <td>9</td>  
                    <td>Dell</td>
                    <td>United Kingdom</td>
                </tr>  
                <tr>  
                    <td>10</td>  
                    <td>Trump</td>  
                    <td>France</td>  
                </tr>  
            </table>  
        </div>
    </body>
</html>
<script src="https://code.jquery.com/jquery-3.6.1.min.js" integrity="sha256-o88AwQnZB+VDvE9tvIXrMQaPlFFSUTR+nldQm1LuPXQ=" crossorigin="anonymous"></script>
<script>
$(document).ready (function () {  
    $('#data').after ('<div id="nav"></div>');  
    var rowsShown = 5;  
    var rowsTotal = $('#data tbody tr').length;  
    var numPages = rowsTotal/rowsShown;  
    for (i = 0;i < numPages;i++) {  
        var pageNum = i + 1;  
        $('#nav').append ('<a href="#" rel="'+i+'">'+pageNum+'</a> ');  
    }  
    $('#data tbody tr').hide();  
    $('#data tbody tr').slice (0, rowsShown).show();  
    $('#nav a:first').addClass('active');  
    $('#nav a').bind('click', function() {  
    $('#nav a').removeClass('active');  
    $(this).addClass('active');  
        var currPage = $(this).attr('rel');  
        var startItem = currPage * rowsShown;  
        var endItem = startItem + rowsShown;  
        $('#data tbody tr').css('opacity','0.0').hide().slice(startItem, endItem).  
        css('display','table-row').animate({opacity:1}, 300);  
    });  
});
</script>

Выход:

Пример:

В этом примере мы создадим пагинацию с помощью плагина twbsPagination . Этот плагин jQuery упрощает использование разбиения на страницы Bootstrap.

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>jQuery Pagination Using Plugin - Websolutionstuff</title>
        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.6/css/bootstrap.min.css">
        <style>
            .wrapper{
                margin: 60px auto;
                text-align: center;
            }
            h2{
                margin-bottom: 1.25em;
            }
            
            #pagination-demo{
                display: inline-block;
                margin-bottom: 1.75em;
            }

            #pagination-demo li{
                display: inline-block;
            }

            .page-content{
                background: #eee;
                display: inline-block;
                padding: 10px;
                width: 100%;
                max-width: 660px;
            }
        </style>
    </head>
    <body>                  
        <div class="wrapper">
            <div class="container">
              
              <div class="row">
                <div class="col-sm-12">
                  <h2>jQuery Pagination Using Plugin - Websolutionstuff</h2>
                  <p>Simple pagination using the TWBS pagination JS library.</p>
                  <ul id="pagination-demo" class="pagination-sm"></ul>
                </div>
              </div>
          
              <div id="page-content" class="page-content">Page 1</div>
            </div>
          </div>
    </body>
</html>
<script src="https://code.jquery.com/jquery-3.6.1.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.6/js/bootstrap.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twbs-pagination/1.4.1/jquery.twbsPagination.min.js"></script>
<script>
$(document).ready (function () {  
    $('#pagination-demo').twbsPagination({
        totalPages: 16,
        visiblePages: 6,
        next: 'Next',
        prev: 'Prev',
        onPageClick: function (event, page) {            
            $('#page-content').text('Page ' + page) + ' content here';
        }
    });
});
</script>

Выход:

Оригинальный источник статьи: https://websolutionstuff.com/

#jquery #pagination 

Applications Of Data Science On 3D Imagery Data

CVDC 2020, the Computer Vision conference of the year, is scheduled for 13th and 14th of August to bring together the leading experts on Computer Vision from around the world. Organised by the Association of Data Scientists (ADaSCi), the premier global professional body of data science and machine learning professionals, it is a first-of-its-kind virtual conference on Computer Vision.

The second day of the conference started with quite an informative talk on the current pandemic situation. Speaking of talks, the second session “Application of Data Science Algorithms on 3D Imagery Data” was presented by Ramana M, who is the Principal Data Scientist in Analytics at Cyient Ltd.

Ramana talked about one of the most important assets of organisations, data and how the digital world is moving from using 2D data to 3D data for highly accurate information along with realistic user experiences.

The agenda of the talk included an introduction to 3D data, its applications and case studies, 3D data alignment, 3D data for object detection and two general case studies, which are-

• Industrial metrology for quality assurance.
• 3d object detection and its volumetric analysis.

This talk discussed the recent advances in 3D data processing, feature extraction methods, object type detection, object segmentation, and object measurements in different body cross-sections. It also covered the 3D imagery concepts, the various algorithms for faster data processing on the GPU environment, and the application of deep learning techniques for object detection and segmentation.

#developers corner #3d data #3d data alignment #applications of data science on 3d imagery data #computer vision #cvdc 2020 #deep learning techniques for 3d data #mesh data #point cloud data #uav data