<style>
#mychart {
    margin:10px 10px 10px 10px;
    width:90%;
    max-width: 800px;
    height:400px;
}
</style>
<div class="intro">
<p>This example shows how to customize the default tooltip of a `Chart`.</p>
</div>
<div class="example">
{{>charts-customizedtooltip-source}}
</div>

<h3>This example shows how to customize the tooltip for a `Chart`.</h3>

<p>A `Chart` instance comes with a simple default tooltip. This tooltip is represented by the `tooltip` attribute. Through the tooltip attribute you can do the following:
<ul>
    <li>Style the tooltip background, border and text.</li>
    <li>Customize and format the tooltip message.</li>
    <li>Change the show and hide events.</li>
    <li>Disable the tooltip.</li>
</ul>
</p>
<p>The `tooltip` attribute contains the following properties:

 <dl>
     <dt>node</dt><dd>Reference to the actual dom node</dd>
     <dt>showEvent</dt><dd>Event that should trigger the tooltip</dd>
     <dt>hideEvent</dt><dd>Event that should trigger the removal of a tooltip (can be an event or an array of events)</dd>
     <dt>styles</dt><dd>A hash of style properties that will be applied to the tooltip node</dd>
     <dt>show</dt><dd>Indicates whether or not to show the tooltip</dd>
     <dt>markerEventHandler</dt><dd>Displays and hides tooltip based on marker events</dd>
     <dt>planarEventHandler</dt><dd>Displays and hides tooltip based on planar events</dd>
     <dt>markerLabelFunction</dt><dd>Reference to the function used to format a marker event triggered tooltip's text. The method contains 
     the following arguments:
         <dl>
             <dt>categoryItem</dt><dd>An object containing the following:
                 <dl>
                     <dt>axis</dt><dd>The axis to which the category is bound.</dd>
                     <dt>displayName</dt><dd>The display name set to the category (defaults to key if not provided).</dd>
                     <dt>key</dt><dd>The key of the category.</dd>
                     <dt>value</dt><dd>The value of the category.</dd>
                 </dl>
             </dd>
             <dt>valueItem</dt><dd>An object containing the following:
                 <dl>
                     <dt>axis</dt><dd>The axis to which the item's series is bound.</dd>
                     <dt>displayName</dt><dd>The display name of the series. (defaults to key if not provided)</dd>
                     <dt>key</dt><dd>The key for the series.</dd>
                     <dt>value</dt><dd>The value for the series item.</dd> 
                 </dl>
             </dd>
             <dt>itemIndex</dt><dd>The index of the item within the series.</dd>
             <dt>series</dt><dd> The `CartesianSeries` instance of the item.</dd>
             <dt>seriesIndex</dt><dd>The index of the series in the `seriesCollection`.</dd>
         </dl>
     The method returns an `HTMLElement` which is written into the DOM using `appendChild`. If you override this method and choose to return an html string, you
     will also need to override the tooltip's `setTextFunction` method to accept an html string.
     </dd>
     <dt>planarLabelFunction</dt><dd>Reference to the function used to format a planar event triggered tooltip's text
         <dl>
             <dt>categoryAxis</dt><dd> `CategoryAxis` Reference to the categoryAxis of the chart.
             <dt>valueItems</dt><dd>Array of objects for each series that has a data point in the coordinate plane of the event. Each object contains the following data:
                 <dl>
                     <dt>axis</dt><dd>The value axis of the series.</dd>
                     <dt>key</dt><dd>The key for the series.</dd>
                     <dt>value</dt><dd>The value for the series item.</dd>
                     <dt>displayName</dt><dd>The display name of the series. (defaults to key if not provided)</dd>
                 </dl> 
             </dd>
             <dt>index</dt><dd>The index of the item within its series.</dd>
             <dt>seriesArray</dt><dd>Array of series instances for each value item.</dd>
             <dt>seriesIndex</dt><dd>The index of the series in the `seriesCollection`.</dd>
         </dl>
     The method returns an `HTMLElement` which is written into the DOM using `appendChild`. If you override this method and choose to return an html string, you
     will also need to override the tooltip's `setTextFunction` method to accept an html string.
     </dd>
     <dt>setTextFunction</dt><dd>Method that writes content returned from `planarLabelFunction` or `markerLabelFunction` into the the tooltip node.
     has the following signature:
         <dl>
             <dt>label</dt><dd>The `HTMLElement` that the content is to be added.</dd>
             <dt>val</dt><dd>The content to be rendered into tooltip. This can be a `String` or `HTMLElement`. If an HTML string is used, it will be rendered as a
             string.</dd>
         </dl>
     </dd>
</dl>

<p>In this example, we have changed the styles and set a custom `markerLabelFunction` to format the text.</p>

<h4>CSS</h4>
```
#mychart {
    margin:10px 10px 10px 10px;
    width:90%;
    max-width: 800px;
    height:400px;
}
```

<h4>HTML</h4>
```
<div id="mychart"></div>
```

<h4>JavaScript</h4>
```
var myDataValues = [ 
    {category:"5/1/2010", Miscellaneous:2000, Expenses:3700, Revenue:2200}, 
    {category:"5/2/2010", Miscellaneous:50, Expenses:9100, Revenue:100}, 
    {category:"5/3/2010", Miscellaneous:400, Expenses:1100, Revenue:1500}, 
    {category:"5/4/2010", Miscellaneous:200, Expenses:1900, Revenue:2800}, 
    {category:"5/5/2010", Miscellaneous:5000, Expenses:5000, Revenue:2650}
];

var myTooltip = {
    styles: { 
        backgroundColor: "#333",
        color: "#eee",
        borderColor: "#fff",
        textAlign: "center"
    },
    markerLabelFunction: function(categoryItem, valueItem, itemIndex, series, seriesIndex)
    {
        var msg = document.createElement("div"),
            underlinedTextBlock = document.createElement("span"),
            boldTextBlock = document.createElement("div");
        underlinedTextBlock.style.textDecoration = "underline";
        boldTextBlock.style.marginTop = "5px";
        boldTextBlock.style.fontWeight = "bold";
        underlinedTextBlock.appendChild(document.createTextNode(valueItem.displayName + " for " + 
                                        categoryItem.axis.get("labelFunction").apply(this, [categoryItem.value, categoryItem.axis.get("labelFormat")])));
        boldTextBlock.appendChild(document.createTextNode(valueItem.axis.get("labelFunction").apply(this, [valueItem.value, {prefix:"$", decimalPlaces:2}])));   
        msg.appendChild(underlinedTextBlock);
        msg.appendChild(document.createElement("br"));
        msg.appendChild(boldTextBlock); 
        return msg; 
    }
};

var mychart = new Y.Chart({
                    dataProvider:myDataValues, 
                    type:"bar",
                    render:"#mychart", 
                    tooltip: myTooltip
                });
```

