Hiding columns in table JavaScript

Question

This script stops working the moment I add a table inside a table, so how to get it worked? I don\'t need any jQuery solutions, I want pure JavaScript. Here\'s my sc

Answer 1

I had a situation where it would have been a very big hassle to modify every single TD value and add the appropriate class name so I could toggle it. As a result I wrote some JavaScript to do that automatically. Please see the following code.

  tbl = document.getElementById("Mytable")
  classes = getClasses(tbl.rows[0]);
  setClasses(tbl, classes);
  toggleCol("col0");
  toggleCol("col1");



function getClasses(row){
    var cn = 0;
    var classes = new Array();
    for(x=0; x < row.cells.length; x++){
        var cell = row.cells[x];
        var c = new Column(cell.textContent.trim(), cell.offsetLeft, cell.offsetLeft + cell.offsetWidth, x);
        classes[x]= c;
    }
    return classes;
}

function Column(name, left, right, cols) {
    this.name = name;
    this.left = left;
    this.right = right;
    this.cols = cols;
}

function setClasses(table, classes){
    var rowSpans = new Array();
    for(x=0; x < table.rows.length; x++){
        var row = table.rows[x]; 
        for(y=0; y < row.cells.length; y++){
            var cell = row.cells[y];
            for(z=0; z < classes.length; z++){
              if(cell.offsetLeft >= classes[z].left && cell.offsetLeft <= classes[z].right){
                cell.className = "col" + classes[z].cols;
              }
            }
        }    
    }
}

function toggleCol(name){ 
  var cols = document.getElementsByClassName(name); 
  for(x=0; x < cols.length; x++){ 
    cols[x].style.display= (cols[x].style.display == 'none') ? '' : 'none'; 
   }
}

In my example I take a look at the first row to set the top level header (In my example I had several who had colspans). It uses the offsetLeft and offsetWidth to determine the range of the top header (which in my cases has sub headers), so that all sub-columns would toggle with its parent.

Based on these values setClasses sets the appropriate classes to all the elements.

In my example I then toggle "col0" and "col1", so they would be invisible (Running the function again would make them visible again).