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# Example: Creating a Universal Console

In this example, three YUI instances are created, each binding a button to call `Y.log(...)`. Then an additional, separate YUI instance is created that requests only the `console` module and creates a Console that listens for log events from all three.

#### YUI #1

#### YUI #2

#### YUI #3

### Multiple YUI instances

Each YUI instance is its own sandbox. You can create as many YUI instances on a page as you want or need (though typically one is enough). The variables, module configurations and instances are kept inside that instance unless you expressly expose them via a global variable.

    // Create the first YUI instance
    YUI().use("node", function (Y) {

        Y.one( "#yui1" ).on( "click", function () {
            Y.log( "Message from YUI instance #1" );
        });

    });

    // Create the second YUI instance
    YUI().use("node", function (Y) {

        Y.one( "#yui2" ).on( "click", function () {
            Y.log( "I'm the second YUI instance" );
        });

    });

    // Create a third YUI instance
    YUI().use("node", function (Y) {

        Y.one( "#yui3" ).on( "click", function () {
            Y.log( "And this is #3 YUI" );
        });

    });

### Listening to `Y.Global`

To address debugging such an environment, Console can be configured to listen for log messages across all YUI instances by setting the Console instance's `logSource` configuration to `Y.Global`.

We'll insert the universal Console into another YUI instance.

    // Create a separate YUI instance to listen to all instances' logging
    YUI().use("console", function (Y) {

        // Configure the Console's logSource to Y.Global to make it universal
        new Y.Console({
            logSource: Y.Global,
            style: 'block',
            newestOnTop: false,
            width: "250px"
        }).render( "#yconsole" );

    });

### Full Code Listing

#### Markup

    <div id="demo" class="yui3-skin-sam">
        <div class="yui3-g">
            <div class="yui3-u-1-2 first">
                <h4>YUI #1</h4>
                <button type="button" id="yui1">Log from YUI instance #1</button>

                <h4>YUI #2</h4>
                <button type="button" id="yui2">Log from YUI instance #2</button>

                <h4>YUI #3</h4>
                <button type="button" id="yui3">Log from YUI instance #3</button>
            </div>
            <div class="yui3-u-1-2" id="yconsole">
            </div>
        </div>
        <div class="clr"></div>
    </div>

#### JavaScript

    <script>

    // Create the first YUI instance
    YUI().use("node", function (Y) {

        Y.one( "#yui1" ).on( "click", function () {
            Y.log( "Message from YUI instance #1" );
        });

    });

    // Create the second YUI instance
    YUI().use("node", function (Y) {

        Y.one( "#yui2" ).on( "click", function () {
            Y.log( "I'm the second YUI instance" );
        });

    });

    // Create a third YUI instance
    YUI().use("node", function (Y) {

        Y.one( "#yui3" ).on( "click", function () {
            Y.log( "And this is #3 YUI" );
        });

    });

    // Create a separate YUI instance to listen to all instances' logging
    YUI().use("console", function (Y) {

        // Configure the Console's logSource to Y.Global to make it universal
        new Y.Console({
            logSource: Y.Global,
            style: 'inline',
            newestOnTop: false
        }).render( "#yconsole" );

    });

    </script>

#### CSS

    <style>
    #yconsole {
        text-align: right;
    }

    #demo .first button {
        margin-bottom: 2em;
    }

    #demo .yui3-console .yui3-console-title {
        border: 0 none;
        color: #000;
        font-size: 13px;
        font-weight: bold;
        margin: 0;
        text-transform: none;
    }
    #demo .yui3-console .yui3-console-entry-meta {
        margin: 0;
    }

    .clr {
        clear: both;
    }
    </style>