Step 1: Prepare your markup

Let's suppose you're using a <form> with hidden <input> elements to record the ordering of the images in your collections. (For a description of how to use this <form> approach, see Talking to the Server Using The afterMove Event.) A simple example of this could be:

<form action="#">
    <a href="myImage1.jpg">
        <img src="myImage1.jpg" alt="image 1 thumbnail" />
        <span>Image 1</span>
        <input name="image 1" value="0" type="hidden" /> 
    </a>
    <a href="myImage2.jpg">
        <img src="myImage2.jpg" alt="image 2 thumbnail" />
        <span>Image 2</span>
        <input name="image 2" value="1" type="hidden" /> 
    </a>
    <a href="myImage3.jpg">
        <img src="myImage3.jpg" alt="image 3 thumbnail" />
        <span>Image 3</span>
        <input name="image 3" value="2" type="hidden" /> 
    </a>
    ...
</form>

The Image Reorderer needs to know about the 'container' of your image collection. In this case, that would be the <form> element. But since there may be other <form> elements in the markup, you will need to uniquely identify the <form> you want to use as a container.

The Reorderer accepts a jQuery selector, so you can choose any method that will uniquely identify the <form> element. We'll attach a unique ID to it:

<form action="#" id="reorder-images-form">
    ...

You also need to tell the Reorderer which of your images should be reorderable and most of the time, that will likely be all of them. But perhaps you want the first image to always be first since it's the cover of the album - with the Image Reorderer this is possible. For this tutorial, though, we'll make all contained images movable.

You'll tell the Reorderer which items are to be orderable with another jQuery selector. The Image Reorderer understands a default class name for this purpose, but you can override that if you like. For this tutorial, we'll stick with the defaults classname flc-imageReorderer-item. Let's add that to each of the <a> elements:

<form action="#" id="reorder-images-form">
    <a href="myImage1.jpg" class="flc-imageReorderer-item">
        <img src="myImage1.jpg" alt="image 1 thumbnail" />
        <span>Image 1</span>
        <input name="image 1" value="0" type="hidden" /> 
    </a>
    <a href="myImage2.jpg" class="flc-imageReorderer-item">
        <img src="myImage2.jpg" alt="image 2 thumbnail" />
        <span>Image 2</span>
        <input name="image 2" value="1" type="hidden" /> 
    </a>
    <a href="myImage3.jpg" class="flc-imageReorderer-item">
        <img src="myImage3.jpg" alt="image 3 thumbnail" />
        <span>Image 3</span>
        <input name="image 3" value="2" type="hidden" /> 
    </a>
    ...
</form>

Finally, you'll want to tell the Image Reorderer which part of your markup is the caption for the image. The Image Reorderer will use this information to help make your image collection more usable by people using assistive technologies, such as a screen reader.

You can identify the captions using the default selector classname, flc-reorderer-imageTitle:

<form action="#" id="reorder-images-form">
    <a href="myImage1.jpg" class="flc-imageReorderer-item">
        <img src="myImage1.jpg" alt="image 1 thumbnail" />
        <span class="flc-reorderer-imageTitle">Image 1</span>
        <input name="image 1" value="0" type="hidden" /> 
    </a>
    <a href="myImage2.jpg" class="flc-imageReorderer-item">
        <img src="myImage2.jpg" alt="image 2 thumbnail" />
        <span class="flc-reorderer-imageTitle">Image 2</span>
        <input name="image 2" value="1" type="hidden" /> 
    </a>
    <a href="myImage3.jpg" class="flc-imageReorderer-item">
        <img src="myImage3.jpg" alt="image 3 thumbnail" />
        <span class="flc-reorderer-imageTitle">Image 3</span>
        <input name="image 3" value="2" type="hidden" /> 
    </a>
    ...
</form>

Step 2: Write the script

You'll need to create a file to contain your initialization script - the script you write to apply the Reorderer to your image collection.

jQuery(document).ready(function () {
    return fluid.reorderImages("#reorder-images-form");
});

jQuery(document).ready(function () {
    var opts = {
        selectors: {
            movables: "[id^=pic-movable]"
        }
    };
    return fluid.reorderImages("#reorder-images-form", opts);
});

Step 3: Add the script to your HTML

You'll need to add your initialization script, along with the Infusion library, to you HTML file. In the header of the file, link to the Javascript files with <script> tags:

<script type="text/javascript" src="infusion-1.2/InfusionAll.js"></script>
<script type="text/javascript" src="image-collection.js"></script>

Keep in mind that the InfusionAll.js file is minified - all of the whitespace has been removed - so it isn't really human-readable. If you're using the source distribution and you want to be able to debug the code, you'll want to include each of the required files individually. This would look like this:

<script type="text/javascript" src="infusion-1.2/lib/jquery/core/js/jquery.js"></script>
<script type="text/javascript" src="infusion-1.2/lib/jquery/ui/js/jquery.ui.core.js"></script>
<script type="text/javascript" src="infusion-1.2/lib/jquery/ui/js/jquery.ui.widget.js"></script>
<script type="text/javascript" src="infusion-1.2/lib/jquery/ui/js/jquery.ui.mouse.js"></script>
<script type="text/javascript" src="infusion-1.2/lib/jquery/ui/js/jquery.ui.draggable.js"></script>
<script type="text/javascript" src="infusion-1.2/framework/core/js/jquery.keyboard-a11y.js"></script>
<script type="text/javascript" src="infusion-1.2/framework/core/js/Fluid.js"></script>
<script type="text/javascript" src="infusion-1.2/framework/core/js/FluidDOMUtilities.js"></script>
<script type="text/javascript" src="infusion-1.2/components/reorderer/js/GeometricManager.js"></script>
<script type="text/javascript" src="infusion-1.2/components/reorderer/js/Reorderer.js"></script>
<script type="text/javascript" src="infusion-1.2/components/reorderer/js/ImageReorderer.js"></script>
<script type="text/javascript" src="image-collection.js"></script>

But all of these individual files are not necessary to make it work - the InfusionAll.js file has everything you need.

That's it! That's all you need to do to make your images reorderable!

Step 4: Apply styles

You can style your image gallery any way you choose (of course), but the Infusion Image Reorderer comes with a set of CSS styles that have been carefully created by interface and interaction designers.

Using the default styles

You can take advantage of the Image Reorderer styles provided with the component by simply adding the default styling class names to your markup. The Image Reorderer will take care of the rest.

There are three things you'll want to add styling classnames to:

1. the container element, using fl-imageReorderer and fl-reorderer-horizontalLayout,
2. the reorderable elements themselves, using fl-imageReorderer-item, and
3. the captions, using fl-imageReorderer-caption.

<form action="#" id="reorder-images-form" class="fl-imageReordererfl-reorderer-horizontalLayout">
    <a href="myImage1.jpg" class="flc-imageReorderer-item fl-imageReorderer-item">
        <img src="myImage1.jpg" alt="image 1 thumbnail" />
        <span class="flc-reorderer-imageTitle fl-imageReorderer-caption">Image 1</span>
        <input name="image 1" value="0" type="hidden" /> 
    </a>
    <a href="myImage2.jpg" class="flc-imageReorderer-item fl-imageReorderer-item">
        <img src="myImage2.jpg" alt="image 2 thumbnail" />
        <span class="flc-reorderer-imageTitle fl-imageReorderer-caption">Image 2</span>
        <input name="image 2" value="1" type="hidden" /> 
    </a>
    <a href="myImage3.jpg" class="flc-imageReorderer-item fl-imageReorderer-item">
        <img src="myImage3.jpg" alt="image 3 thumbnail" />
        <span class="flc-reorderer-imageTitle fl-imageReorderer-caption">Image 3</span>
        <input name="image 3" value="2" type="hidden" /> 
    </a>
    ...
</form>

The fl-reorderer-horizontalLayout will lay the images out horizontally, and will make sure that the drop marker shows up between the thumbnails properly.

Customizing the styles

If you choose to use CSS classname different than the defaults, you can override the defaults using the options parameter to the reorderImages() function.

Specify your classnames using the {[styles}} option, and the required style names:

var opts = {
    styles: {
        defaultStyle: "myMovableImage",
        imageTitle: "myImageCaption"
    },
};
return fluid.reorderImages("#reorder-images-form", opts);

There are actually many styles used by the Reorderer, affecting how the thumbnails look when the cursor hovers over them, what the avatar looks like while it's being dragged, what the drop marker looks like, and more. For a complete list of styles, see the full technical documentation: Image Reorderer API.