Bersion 2.x

<link rel="stylesheet" href="gridzy/gridzy.min.css" />
<script src="gridzy/gridzy.min.js"></script>

<div class="gridzy">
  <img src="https://loremflickr.com/640/480?random=1" alt="a random image" />
  <img src="https://loremflickr.com/480/640?random=2" alt="another random image" />
  <img src="https://loremflickr.com/640/640?random=3" alt="yet another random image" />
  <img src="https://loremflickr.com/640/480?random=4" alt="a random image again" />
  <img src="https://loremflickr.com/640/480?random=5" alt="one last random image" />
</div>

<div class="gridzy" data-gridzy-spaceBetween="20" data-gridzy-desiredHeight="400">
  <img src="https://loremflickr.com/640/480?random=1" alt="a random image" />
  <img src="https://loremflickr.com/480/640?random=2" alt="another random image" />
  <img src="https://loremflickr.com/640/640?random=3" alt="yet another random image" />
  <img src="https://loremflickr.com/640/480?random=4" alt="a random image again" />
  <img src="https://loremflickr.com/640/480?random=5" alt="one last random image" />
</div>

<div class="gridzy">
  <img src="https://loremflickr.com/640/480?random=1" alt="a random image" />
  <img src="https://loremflickr.com/480/640?random=2" alt="another random image" />
  <img src="https://loremflickr.com/640/640?random=3" alt="yet another random image" />
  <img src="https://loremflickr.com/640/480?random=4" alt="a random image again" />
  <img src="https://loremflickr.com/640/480?random=5" alt="one last random image" />
</div>

<ul class="gridzy">
  <li>
    <span>
      <img class="gridzyImage" src="https://loremflickr.com/640/480?random=1" alt="a random image" />
    </span>
  </li>
  <li>
    <span>
      <img class="gridzyImage" src="https://loremflickr.com/480/640?random=2" alt="another random image" />
    </span>
  </li>
  <li>
    <span>
      <img class="gridzyImage" src="https://loremflickr.com/640/640?random=3" alt="yet another random image" />
    </span>
  </li>
  <li>
    <span>
      <img class="gridzyImage" src="https://loremflickr.com/640/480?random=4" alt="a random image again" />
    </span>
  </li>
  <li>
    <span>
      <img class="gridzyImage" src="https://loremflickr.com/640/480?random=5" alt="one last random image" />
    </span>
  </li>
</ul>

<link rel="stylesheet" href="gridzy/skins/gridzySkinClassic/style.min.css" />

<div class="gridzy gridzySkinClassic">
  <figure>
    <img class="gridzyImage" src="https://loremflickr.com/640/480?random=1" alt="a random image" />
    <figcaption class="gridzyCaption">a caption text</figcaption>
  </figure>
  <figure>
    <img class="gridzyImage" src="https://loremflickr.com/480/640?random=2" alt="another random image" />
    <figcaption class="gridzyCaption">another caption text</figcaption>
  </figure>
  <figure>
    <img class="gridzyImage" src="https://loremflickr.com/640/640?random=3" alt="yet another random image" />
    <figcaption class="gridzyCaption">yet another caption text</figcaption>
  </figure>
  <figure>
    <img class="gridzyImage" src="https://loremflickr.com/640/480?random=4" alt="a random image again" />
    <figcaption class="gridzyCaption">a caption text again</figcaption>
  </figure>
  <figure>
    <img class="gridzyImage" src="https://loremflickr.com/640/480?random=5" alt="one last random image" />
    <figcaption class="gridzyCaption">one last caption text</figcaption>
  </figure>
</div>

<link rel="stylesheet" href="gridzy/skins/gridzySkinBlur/style.min.css" />
<script src="gridzy/skins/gridzySkinBlur/script.min.js"></script>

<div class="gridzy gridzySkinClassic" style="--background: rgba(0, 80, 117, .8); --color: rgb(238, 238, 238); ">
  <figure>
    <img class="gridzyImage" src="https://loremflickr.com/640/480?random=1" alt="a random image" />
    <figcaption class="gridzyCaption">a caption text</figcaption>
  </figure>
  <figure>
    <img class="gridzyImage" src="https://loremflickr.com/480/640?random=2" alt="another random image" />
    <figcaption class="gridzyCaption">another caption text</figcaption>
  </figure>

  ...

</div>

/** SKIN Blank **/

/* all gallery items (direct children of the main container element) */
.gridzySkinBlank > .gridzyItem {
  overflow: hidden;
}

/* all gallery images (predefined in Gridzy's main CSS file, but can be overridden) */
.gridzySkinBlank .gridzyImage {
}

/* all gallery captions (just create your very own style) */
.gridzySkinBlank .gridzyCaption {
  margin: 0;
  padding: .5em;
  opacity: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  position: absolute;
  z-index: 1;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  transition: opacity .5s;
  overflow: auto;
  background: rgba(0, 0, 0, .7);
  color: rgb(255, 255, 255);
}

.gridzySkinBlank > .gridzyItem:hover .gridzyCaption {
  opacity: 1;
}

<div class="gridzy">
  <img src="https://loremflickr.com/640/480?random=1" width="640" height="480" alt="a random image" />
  <img src="https://loremflickr.com/480/640?random=2" width="480" height="640" alt="another random image" />
  <img src="https://loremflickr.com/640/640?random=3" width="640" height="640" alt="yet another random image" />
  <img src="https://loremflickr.com/640/480?random=4" width="640" height="480" alt="a random image again" />
  <img src="https://loremflickr.com/640/480?random=5" width="640" height="480" alt="one last random image" />
</div>

<div class="gridzy">
  <img data-gridzylazysrc="https://loremflickr.com/640/480?random=1" width="640" height="480" alt="a random image" />
  <img data-gridzylazysrc="https://loremflickr.com/480/640?random=2" width="480" height="640" alt="another random image" />
  <img data-gridzylazysrc="https://loremflickr.com/640/640?random=3" width="640" height="640" alt="yet another random image" />
  <img data-gridzylazysrc="https://loremflickr.com/640/480?random=4" width="640" height="480" alt="a random image again" />
  <img data-gridzylazysrc="https://loremflickr.com/640/480?random=5" width="640" height="480" alt="one last random image" />
</div>

<div class="gridzy">
  <div><img src="https://loremflickr.com/640/480?random=1" class="gridzyImage" alt="a random image" /></div>
  <div><img src="https://loremflickr.com/480/640?random=2" class="gridzyImage" alt="another random image" /></div>
  <div><img src="https://loremflickr.com/640/640?random=3" class="gridzyImage" alt="yet another random image" /></div>
  <div><img src="https://loremflickr.com/640/480?random=4" class="gridzyImage" alt="a random image again" /></div>
  <div><img src="https://loremflickr.com/640/480?random=5" class="gridzyImage" alt="one last random image" /></div>
</div>

<div id="myFilterControls">
  <button value="*">All</button>
  <button value=".animals">Animals</button>
  <button value=".architecture">Architecture</button>
  <button value=".people">People</button>
</div>

<div class="gridzy" data-gridzy-filterControls="#myFilterControls button">
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=1" alt="a random animal image" />
  <img class="architecture" src="https://loremflickr.com/640/480/arch?random=1" alt="a random architecture image" />
  <img class="people" src="https://loremflickr.com/640/480/people?random=1" alt="a random people image" />
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=2" alt="another random animal image" />
  <img class="architecture" src="https://loremflickr.com/640/480/arch?random=2" alt="another random architecture image" />
  <img class="people" src="https://loremflickr.com/640/480/people?random=2" alt="another random people image" />
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=3" alt="yet another random animal image" />
</div>

<div class="gridzy">
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=1" alt="a random animal image" />
  <img class="architecture" src="https://loremflickr.com/640/480/arch?random=1" alt="a random architecture image" />
  <img class="people" src="https://loremflickr.com/640/480/people?random=1" alt="a random people image" />
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=2" alt="another random animal image" />
  <img class="architecture" src="https://loremflickr.com/640/480/arch?random=2" alt="another random architecture image" />
  <img class="people" src="https://loremflickr.com/640/480/people?random=2" alt="another random people image" />
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=3" alt="yet another random animal image" />
</div>

<button value="*">All</button>
<button value=".animals">Animals</button>
<button value=".architecture">Architecture</button>
<button value=".people">People</button>

<div class="gridzy">
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=1" alt="a random animal image" />
  <img class="architecture" src="https://loremflickr.com/640/480/arch?random=1" alt="a random architecture image" />
  <img class="people" src="https://loremflickr.com/640/480/people?random=1" alt="a random people image" />
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=2" alt="another random animal image" />
  <img class="architecture" src="https://loremflickr.com/640/480/arch?random=2" alt="another random architecture image" />
  <img class="people" src="https://loremflickr.com/640/480/people?random=2" alt="another random people image" />
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=3" alt="yet another random animal image" />
</div>

<div id="myFilterControls">
  <button value="*">All</button>
  <button value=".animals">Animals</button>
  <button value=".architecture">Architecture</button>
  <button value=".people">People</button>
</div>

<div class="gridzy" data-gridzy-filterControls="#myFilterControls button">
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=1" alt="a random animal image" />
  <img class="architecture" src="https://loremflickr.com/640/480/arch?random=1" alt="a random architecture image" />
  <img class="people" src="https://loremflickr.com/640/480/people?random=1" alt="a random people image" />
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=2" alt="another random animal image" />
  <img class="architecture" src="https://loremflickr.com/640/480/arch?random=2" alt="another random architecture image" />
  <img class="people" src="https://loremflickr.com/640/480/people?random=2" alt="another random people image" />
  <img class="animals" src="https://loremflickr.com/640/480/animals?random=3" alt="yet another random animal image" />
</div>

// get the container element
var gridzyElement = document.querySelector('.gridzy');

// create a new img element
var newImage = document.createElement('img');

// add src attribute (!! before you add it to the container element !!)
newImage.src = 'https://loremflickr.com/640/480';

// add it as last element to the container element
gridzyElement.appendChild(newImage);

// or as first element (or anywhere in between)
gridzyElement.insertBefore(newImage, gridzyElement.firstChild);

// remove the first image
gridzyElement.removeChild(gridzyElement.firstElementChild);

// change the spaceBetween option to a specific value
gridzyElement.setAttribute('data-gridzy-spaceBetween', '10');

// change the layout option to a specific value
gridzyElement.setAttribute('data-gridzy-layout', 'waterfall');

// reset the spaceBetween option to its default value
gridzyElement.removeAttribute('data-gridzy-spaceBetween');

// get the Gridzy instance
var gridzyInstance = document.querySelector('.gridzy').gridzy;

// get the value of a single option
var currentLayout = gridzyInstance.getOption('layout');

// get all option values as an object
var currentOptions = gridzyInstance.getOptions();

// set specific option values
gridzyInstance.setOptions({
  spaceBetween: 10,
  layout: 'waterfall'
});

// or reset options to their default values
gridzyInstance.setOptions({
  spaceBetween: null,
  layout: null
});

// set the filter to match items with class "animals"
gridzyInstance.setOptions({
  filter: '.animals'
});

// reset the filter to match all items again
gridzyInstance.setOptions({
  filter: '*'
});

// set the filter to match items without class "animals"
gridzyInstance.setOptions({
  filter: ':not(.animals)'
});

// set the filter to match items with class "animals" or "people"
gridzyInstance.setOptions({
  filter: '.animals, .people'
});

// set the filter to match items that have both classes, "animals" and "people"
gridzyInstance.setOptions({
  filter: '.animals.people'
});

// same as set other options
gridzyInstance.setOptions({
  onOptionsChanged: function() {
    // will be executed each time the options have changed.
  },
  onBeforeOptionsChanged: function() {
    // will be executed, before new options take effect.
  }
});

document.addEventListener('gridzyOptionsChanged', function(event) {
    // will be executed each time the options have changed.
});

document.addEventListener('gridzyBeforeOptionsChanged', function(event) {
    // will be executed, before new options take effect.
});

// get the default value of a single option
var defaultLayout = Gridzy.getDefaultOption('layout');

// get all default option values as an object, including the default layout options of the default layout
var defaultOptions = Gridzy.getDefaultOptions();

// or get all default option values, including the default layout options of a specific layout
var defaultOptions = Gridzy.getDefaultOptions('waterfall');

// set default option values
Gridzy.setDefaultOptions({
  spaceBetween: 10,
  layout: 'waterfall'
});

// disable automatic initializations
Gridzy.setDefaultOptions({
  autoInitOnDomReady: false,
  autoInitOnDomMutation: false
});

// or switch off all mutation observers
Gridzy.setDefaultOptions({
  autoInitOnDomMutation: false,
  autoSyncChildListMutation: false,
  autoSyncAttributesMutation: false,
  autoSyncChildClassMutation: false,
  autoSyncImageMutation: false
});

// initialize a new Gridzy instance
var gridzyInstance = new Gridzy(document.querySelector('.gridzy'), {
  spaceBetween: 10,
  layout: 'waterfall'
});

gridzyInstance.destroy();
gridzyInstance = null;

// after child elements (images) are added to or removed from the DOM.
gridzyInstance.syncChildList();

// after child elements (images) are added to the DOM and only one of them should be synced to Gridzy.
gridzyInstance.syncChild(childElement);

// after data-gridzy- attributes have changed
gridzyInstance.syncAttributes();

gridzyInstance.render();