ChartDirector Ver 3.1 is minor release currently available only on ASP/COM/VB, .NET, Java and PHP.

In previous versions of ChartDirector for ASP/COM/VB, for Visual Basic Windows applications, the ChartDirector documentation recommended using Visual Basic Image controls for displaying chart images. The documentation did not mention how to support clickable charts or tool tips.

A sample project was later posted in the ChartDirector Forum to demontrate how to support clickable charts and tool tips. The method required hooking into the mouse events handlers of the Image control, and used a library to determine the hot spots and display tool tips.

In ChartDirector Ver 3.1, the above functions are integrated into the ChartViewer ActiveX control. It provides integral tool tip support, and generates various events (eg. ClickHotSpot, MouseDownHotSpot, etc) when mouse actions occur on a hot spot.

In previous versions of ChartDirector for .NET, when using Visual Studio.NET for ASP.NET applications, the ChartDirector documentation recommended using ASP.NET Image controls for displaying chart images and ASP.NET Literal controls for the image maps. Furthermore, a utility "myimage.aspx" is needed to support the code- behind programming style or image maps.

In ChartDirector Ver 3.1, the above functions are integrated into the WebChartViewer control. It is a server side Web Forms control. It combines chart image display and image map output functions, and generates the necessary code to bind the image to the image map. It also eliminates the need for the external "myimage.aspx" utility.

In addition, the WebChartViewer control allows image maps to trigger "post back" events. Clicking a hot spot on the chart image can cause an "ClickHotSpot" event to occur at the server side.

Because of the convenience and usefulness of the WebChartViewer control, it is recommended no matter Visual Studio.NET is used or not.

In previous versions of ChartDirector for .NET, for Windows Forms applications, the ChartDirector documentation recommended using Windows Forms PictureBox controls for displaying chart images. The documentation did not mention how to support clickable charts or tool tips.

A sample project was later posted in the ChartDirector Forum to demontrate how to support clickable charts and tool tips. The method required hooking into the mouse events handlers of the PictureBox control, and used a library to determine the hot spots and display tool tips.

In ChartDirector Ver 3.1, the above functions are integrated into the WinChartViewer control. It is a Windows Form control. It provides integral tool tip support, and generates various events (eg. ClickHotSpot, MouseDownHotSpot, etc) when mouse actions occur on a hot spot.

ChartDirector for JSP/Java is now implemented in pure Java, and can work on any Java supporting platform.

In previous versions of ChartDirector for Java, for standalone applications, the ChartDirector sample code use SWING JLabel to display chart images. The documentation did not mention how to support clickable charts or tool tips.

ChartDirector Ver 3.1 comes with a ChartViewer bean that extends JLabel. In addition to displaying charts, it provides tool tips and mouse interaction support for data points on the charts.

Several ChartDirector functions, such as wallpaper, background images, custom data symbols, CDML, etc., supports loading custom images from files. In previous versions of ChartDirector, these files need to be accessible using a file system path.

ChartDirector for Java Ver 3.1 now supports various Java resource loading mechanisms, such as using ClassLoader, servlet context, or URL. This enables loading image files embedded in JAR, WAR or on a remote server (eg. when ChartDirector is used in an Applet on the client side, but the images are on the server side).

ChartDirector for Java now uses Java's font system, so that it can use all Java accessible fonts. ChartDirector also includes an internal font system as a backup, in case the Java font system is not functional (such as on some Linux/UNIX servers with no GUI and without "headless" mode support).

ChartDirector for PHP now includes support for PHP Version 5 - the latest version of PHP.

In previous version of ChartDirector for PHP, the ChartDirector for PHP DLLs or shared objects must be installed in the PHP extension directory. This directory usually requires administration privilege to access. This may be a problem for developers using shared hosts.

In ChartDirector for PHP Ver 3.1, the PHP DLLs or shared objects may now be installed by FTP to the local web server directory (the same directory that contains user PHP scripts). No administration privilege or shell access is required to install ChartDirector for PHP Ver 3.1 (provided the administator does not explicitly disable dynamic PHP extensions).

In ChartDirector, many textual information, including data labels, axis labels, legend keys, tool tips and query parameters for clickable charts are configurable using "parameter substitution".

In ChartDirector Ver 3.1, "parameter substitution" is enhanced to support arithmatic expressions. For example, you can create labels in multiple units easily (eg. temperature in both Celsius and Fahrenheit), since the units can be converted using arithmatic expression. Similarly, you can easily create time labels in multiple time zones, or display other computed values in the labels.

In generating image maps, ChartDirector allows the developer to either specify a template for the entire chart, or to specify a template for each layer in a chart.

If a chart is very complex and contains a lot of layers or different types (such as a complex finance chart), a single template may not need the requirements for all layers, especially for tool tip support. On the other hand, it is inconvenient to specify a separate template for each layer, as there are many layers.

In ChartDirector Ver 3.1, it is possible to specify a general template for the entire chart, and use the Layer.setHTMLImageMap method to override the general template only for layers that need special handling.

Microsoft has documented in its knowledge base that in certain .NET configurations may have intermitten problems handling "Mixed Mode DLLs". As according to Microsoft, this problem will be fixed in .NET platform 1.2. (As of the writing of this release notes, the latest Microsoft .NET platform is 1.1.)

Previous versions of ChartDirector for .NET contains a mixed mode DLL, and therefore may be affected by the above problem. A typical symptom is intermitten "Object reference not set to an instance of an object" error when ChartDirector is first used (usually when invoking chart constructor) after an application domain reload (eg. during project recompilation or modification of the ASP.NET "bin" subdirectory or web.config).

All DLLs in ChartDirector Ver 3.1 are now in "pure mode". As a result, it is not affected by the above issue.

It was discovered in rare cases there may be rounding errors during parameter formatting in parameter substutition. This is now fixed.

As according to ChartDirector documentation, an axis label starting with "~" would have no tick associated with it. In practice, the label would be ignored. This is now fixed.

The fourth argument (boldItalic) of the BaseChart.setDefaultFonts method was ignored. This is now fixed.

When drawing multi-stacked bar in 3D, if the bar widths were configured so that the bars would overlap, the overlapping might be incorrectly drawn during to inproper drawing order. This is now fixed.

The image map for an area chart with x-y axis swapped (rotated area chart) would be incorrect. This is now fixed.