SIngle/Double Bootstrap columns depending on display size preserving content order in each while not wasting space - twitter-bootstrap-3

Question

I have 6 different elements of varying length and I am trying to come up with a bootstrap grid layout that achieves the following.
A two column layout to display in medium and larger displays:
Note that box 3 in the example below starts immediately under box 1 even though box 2 is much longer than box 1.
MD+
|-----|-----|
| 1 | 2 |
|-----| |
| 3 |-----|
|-----| 4 |
| 5 |-----|
|-----| 6 |
|-----|
With the following single column layout for displays smaller than medium:
XS/SM:
|-----|
| 1 |
|-----|
| 2 |
| |
|-----|
| 3 |
|-----|
| 4 |
|-----|
| 5 |
|-----|
| 6 |
|-----|
Just to be thorough, I never want 3 or more columns:
|-----|-----|-----|
| 1 | 2 | 3 |
|-----| |-----|
| 4 |-----| 6 |
|-----| 5 |-----|
|-----|
And the order must remain 1-6, never 1-3 followed by 4-6
I am able to separately achieve the 2 column layout and the single column layouts using the following code but they both break when the display size changes from SM/MD and vice-versa:
Works for XS/SM:
<div class="row">
<div class="col-xs-12 col-md-6"> 1 </div>
<div class="col-xs-12 col-md-6"> 2 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc quis interdum diam, in tempor est. Pellentesque nulla mi, egestas et rhoncus non, rhoncus bibendum velit. Nulla facilisi. Aenean faucibus nulla rutrum elementum cursus. Nam vel varius libero, eu porttitor tortor. In et ultricies nunc. Duis volutpat posuere urna, id faucibus ante lobortis sit amet. Maecenas urna nisl, tristique eget sem vel, semper tincidunt nisi. </div>
<div class="col-xs-12 col-md-6"> 3 </div>
<div class="col-xs-12 col-md-6"> 4 </div>
<div class="col-xs-12 col-md-6"> 5 </div>
<div class="col-xs-12 col-md-6"> 6 </div>
</div>
Works for MD+:
<div class="row">
<div class="col-xs-12 col-md-6">
<div class="row">
<div class="col-xs-12"> 1 </div>
<div class="col-xs-12"> 3 </div>
<div class="col-xs-12"> 5 </div>
</div>
</div>
<div class="col-xs-12 col-md-6">
<div class="row">
<div class="col-xs-12"> 2 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc quis interdum diam, in tempor est. Pellentesque nulla mi, egestas et rhoncus non, rhoncus bibendum velit. Nulla facilisi. Aenean faucibus nulla rutrum elementum cursus. Nam vel varius libero, eu porttitor tortor. In et ultricies nunc. Duis volutpat posuere urna, id faucibus ante lobortis sit amet. Maecenas urna nisl, tristique eget sem vel, semper tincidunt nisi. </div>
<div class="col-xs-12"> 4 </div>
<div class="col-xs-12"> 6 </div>
</div>
</div>
</div>
Is it possible to get the desired layout using Bootstrap 3, and if so, How?

Answer 1

I ended up hacking together a jquery solution that converts the HTML for the
bootstrap grid structure to the layout that works depending on the current
display size.
To facilitate I also hacked together a class function that provides a dz object (displaySize) that not only determines which of the current bootstrap display sizes is active (xs, sm, md, or lg) but also provides a method to execute custom function references registered with the class if the display size changes after reload (window resize event is debounced using underscore).
This is the code I ended up using, if you know how to achieve this using
just the bootstrap grid structure and classes then please post an answer as I
would much rather just do that.
The only change to the HTML is the addition of two class names added to the parent .row element (.custom-layout .custom-layout-2col). Whether you start with the single column layout or the 2 column layout is up to you. just change the second class name to match the layout that you start with. It really doesn't matter which one you start with since the code will change it to the other if needed but you should start with the layout that matches the display size for the majority of your users.
The following shows the added classes for a two column layout:
<div class="row custom-layout custom-layout-2col">
<div class="col-xs-12 col-md-6">
<div class="row">
<div class="col-xs-12"> 1 </div>
<div class="col-xs-12"> 3 </div>
<div class="col-xs-12"> 5 </div>
</div>
</div>
<div class="col-xs-12 col-md-6">
<div class="row">
<div class="col-xs-12"> 2 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc quis interdum diam, in tempor est. Pellentesque nulla mi, egestas et rhoncus non, rhoncus bibendum velit. Nulla facilisi. Aenean faucibus nulla rutrum elementum cursus. Nam vel varius libero, eu porttitor tortor. In et ultricies nunc. Duis volutpat posuere urna, id faucibus ante lobortis sit amet. Maecenas urna nisl, tristique eget sem vel, semper tincidunt nisi. </div>
<div class="col-xs-12"> 4 </div>
<div class="col-xs-12"> 6 </div>
</div>
</div>
</div>
The javascript:
// This is the dz class. Load this after jquery.
// Note that it instantiates itself, just load it on your page.
// Requires the underscore library (or just the _.restArguments, _.delay,
// and _.debounce functions from the library if you want to copy them out
// separately. )
; (function () {
var Def = function () { return constructor.apply(this, arguments); }
var attr = Def.prototype;
//attributes
attr.currentSize = '?';
attr.previousSize = '?';
attr.changeHandler = [];
//constructor
function constructor() {
var self = this;
$(document).ready(function () {
$('.wrapper-content').append('<div class="device-xs hidden-xs"></div><div class="device-sm hidden-sm"></div><div class="device-md hidden-md"></div><div class="device-lg hidden-lg"></div>');
$(window).resize(_.debounce(function () {
self._determineDeviceSize();
}.bind(self), 200));
self._determineDeviceSize();
}.bind(self));
}
//methods
attr.getCurrentSize = function () {
return this.currentSize;
}
attr.getPreviousSize = function () {
return this.previousSize;
}
attr.addChangehandler = function (f) {
if (typeof f === 'function') { this.changeHandler.push(f); }
}
attr._determineDeviceSize = function () {
var c = this.currentSize;
this.currentSize = $('.device-lg').is(':hidden') ? 'lg' : ($('.device-md').is(':hidden') ? 'md' : ($('.device-sm').is(':hidden') ? 'sm' : 'xs'));
if (c !== this.currentSize) {
this.previousSize = c;
// execute any registered size change handler functions
for (i = 0; i < this.changeHandler.length; ++i) {
this.changeHandler[i](this.currentSize, this.previousSize);
}
}
}
//unleash the class (if it hasn't already been)
if (typeof window.dz === 'undefined') {
window.dz = new Def();
}
})();
// Register our function with dz for the work that needs to be done
// if the bootstrap display size changes
dz.addChangehandler(function (csz, psz) {
$('.custom-layout').each(function () {
var parentRow = $(this);
// Change from 1 col to 2 col ?
if (parentRow.is('.custom-layout-1col') && (csz == 'md' || csz == 'lg')) {
var allDivs = parentRow.children('div');
var mCt = allDivs.length;
if (mCt > 0) {
// create the new row/col structure that we will move all the existing .col-* div's into
var id = 'custom' + (new Date).getTime();
var id2 = id + '2';
parentRow.after('<div class="row custom-layout custom-layout-2col"><div class="col-md-6"><div id="' + id + '" class="row"></div></div><div class="col-md-6"><div id="' + id2 + '" class="row"></div></div></div>');
var newOddParent = $('#' + id);
var newEvenParent = $('#' + id2);
var idx = 0;
while (idx < mCt) {
if (idx === 0 || idx % 2 === 0) {
// odd
newOddParent.append($(allDivs[idx]));
} else {
// even
newEvenParent.append($(allDivs[idx]));
}
idx++;
}
// remove the old parent from the DOM
parentRow.remove();
} else {
console.log('Unable to change custom-layout -- Unable to locate any div (col-*) elements in parent: ', parentRow);
}
}
// Change from 2 col to 1 col ?
if (parentRow.is('.custom-layout-2col') && (csz == 'xs' || csz == 'sm')) {
var childRows = parentRow.children('div').children('.row');
if (childRows.length == 2) {
// create the new .row div that we will move all the .col-* div's into
var id = 'custom' + (new Date).getTime();
parentRow.after('<div id="' + id + '" class="row custom-layout custom-layout-1col"></div>');
var newParent = $('#' + id);
// locate all of the col-* div's that we will be moving
var oddRowDivs = $(childRows[0]).children('div');
var evenRowDivs = $(childRows[1]).children('div');
childRows = '';
var oCt = oddRowDivs.length;
var eCt = evenRowDivs.length;
var mCt = Math.max(oCt, eCt);
var idx = 0;
// move the div's directly into the parentDiv in a staggered order
// starting with the odd (left side) div #1, then even (right side) div #2, etc..
while (idx < mCt) {
if (idx < oCt) {
newParent.append($(oddRowDivs[idx]));
}
if (idx < eCt) {
newParent.append($(evenRowDivs[idx]));
}
idx++;
}
// remove the old parent from the DOM
parentRow.remove();
} else {
console.log('Unable to change custom-layout -- Unable to locate the 2 child .row elements in parent: ', parentRow);
}
}
});
});
If anyone is interested the dz class usage is as follows:
dz.getCurrentSize() - value returned will be the current bootstrap display size of the client device: xs, sm, md, or lg
dz.getPreviousSize() - value returned will be the previous bootstrap display size or '?' if the size hasn't changed since page initialization
dz.addChangehandler(functionRef) - Allows you to add your own display size change handler function that will be executed on page load and anytime the display size changes afterwards.
Example usage:
// if all you need is the current display size then use the dzCurrentSize variable
// just make sure your accessing it after jquery's $(document).ready
$(document).ready(function () {
console.log('page size: ' + dz.getCurrentSize());
});
// using a change handler function
dz.addChangehandler(function (currentSize, previousSize) {
// example usage scenarios:
// always do stuff (on page initialization and when the size changes anytime afterwards)
alert("The bootstrap display size is: " + currentSize);
// do stuff ONLY if the size changed after page initialization
if (previousSize !== '?') {
console.log('The size has changed after initialization from: ' + previousSize + ' to: ' + currentSize);
}
// do stuff ONLY on page initialization
if (previousSize === '?') {
console.log('The page has just initialized with a size of: ' + currentSize);
}
});