Guide to creating a nested list using the jQuery :header selector

Question

Guide to creating a nested list using the jQuery :header selector

Here is the structure of my html:

<h1 id="header1">H1</h1>
  <p>Lorem ipsum</p>
    <h2 id="header2">H2</h2>
      <p>lorem ipsum</p>
    <h2 id="header3">H2</h2>
      <p>lorem upsum</p>
       <h3 id="subHeader1">H3</h3>
       <p>Lorem Ipsum</p>

To retrieve all headings with an ID, I am using this jQuery selector:

var headings = $( ":header[id]" );

My goal is to create a nested list of all these headings in this format:

<ul><li>H1
     <ul><li>H2<li>
         <li>H2
           <ul><li>H3</li></ul>
         </li>
      </ul>
 </li></ul>

I have been struggling to achieve this and couldn't find a solution on Stack Overflow. While I can create a flat list, building a nested one has proven to be more challenging.

If anyone could offer assistance or guidance, I would greatly appreciate it. Thank you!

javascript jquery html css nested

Answer 1

Answer №1

Mastering this technique requires a combination of algorithmic knowledge and familiarity with jQuery. It's not as simple as just implementing an algorithm; understanding how to use jQuery properly is crucial in coding it effectively.

The approach involves initializing a root ul, storing references to child headers within each ul, then iterating through this collection to convert each header into a nested ul. These newly created ul elements are added to a stack-like structure, which is processed in a while loop until the stack is empty.

Explaining this process can be challenging, especially for beginners new to algorithms and jQuery. Below is the code snippet demonstrating this technique:

// Initialize the root UL
var ul = $('<ul>');
for(var i = 1; i < 8; i++){
  var hs = $('h' + i);
  if(hs.length){
    ul[0].childHeaders = hs
    ul[0].childHeaderLevel = i;
    break;
  }
}

var rootUl = ul;

// Main loop
while(ul.length){    
  var nextUl = $();
  
  // Loop through each ul
  ul.each(function(){
     var innerUl = this;
     var n = this.childHeaderLevel;
     
     // Convert each childHeader into a ul
     innerUl.childHeaders.each(function(i,elem){
        var childUl = $('<ul>').append('<li>' + $(elem).html() + '</li>')
                               .appendTo(innerUl);
                               
        childUl[0].childHeaders = $(this).nextUntil('h' + n)
                                         .filter('h' + (n+1));
        childUl[0].childHeaderLevel = n + 1;            
        nextUl = nextUl.add(childUl);
     });                            
  });
  
  ul = nextUl;   
}

// Append the root UL to the body after emptying it
$('body').empty().append(rootUl);

See Demo Here.

Answer 2

Mastering this technique requires a combination of algorithmic knowledge and familiarity with jQuery. It's not as simple as just implementing an algorithm; understanding how to use jQuery properly is crucial in coding it effectively.

The approach involves initializing a root ul, storing references to child headers within each ul, then iterating through this collection to convert each header into a nested ul. These newly created ul elements are added to a stack-like structure, which is processed in a while loop until the stack is empty.

Explaining this process can be challenging, especially for beginners new to algorithms and jQuery. Below is the code snippet demonstrating this technique:

// Initialize the root UL
var ul = $('<ul>');
for(var i = 1; i < 8; i++){
  var hs = $('h' + i);
  if(hs.length){
    ul[0].childHeaders = hs
    ul[0].childHeaderLevel = i;
    break;
  }
}

var rootUl = ul;

// Main loop
while(ul.length){    
  var nextUl = $();
  
  // Loop through each ul
  ul.each(function(){
     var innerUl = this;
     var n = this.childHeaderLevel;
     
     // Convert each childHeader into a ul
     innerUl.childHeaders.each(function(i,elem){
        var childUl = $('<ul>').append('<li>' + $(elem).html() + '</li>')
                               .appendTo(innerUl);
                               
        childUl[0].childHeaders = $(this).nextUntil('h' + n)
                                         .filter('h' + (n+1));
        childUl[0].childHeaderLevel = n + 1;            
        nextUl = nextUl.add(childUl);
     });                            
  });
  
  ul = nextUl;   
}

// Append the root UL to the body after emptying it
$('body').empty().append(rootUl);

Guide to creating a nested list using the jQuery :header selector

Answer №1

See Demo Here.

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