Since we released Chart FX Internet many large corporations have incorporated
Chart FX as an essential reporting tool for their Internet, intranet and extranet sites. Many of these companies impose strict security on their users through the use of firewalls and proxy servers; some of them even go to the extent of configuring the browser so it does not accept anything that may become harmful to their network. Needless to say many of these companies do not allow users to download and use Client Control objects, even if they come from trusted third party vendors like Software FX.
Even though Chart FX for Java always generates images by default, for many corporations the fact that these images are being generated and stored in a particular directory poses a security concern to many of them. For example, a hacker could determine a chart name, create a page and
load the chart in his machine before it is actually erased. Many sites display very sensitive data where that risk is simply unacceptable.
With this security concern in mind, Chart FX allows web developers to easily setup pages that return charts as "bit stream" instead of generating chart files and letting browsers download files that were previously generated
in the Temp directory.
The getHtmlData method is a method provided by Chart FX for Java that allows the browser to receive a BitStream
instead of a chart file from the Temp directory of your web
server. The getHtmlData method receives the same parameters as the getHtmlTag method, except that the result will be a data push directly to the browser. No references to download a file will be generated when using this GetHtmlData method.
In fact, when the user attempts to view the source for the resulting page, no information about the chart file will be displayed. This is because all the necessary information was sent to the browser via a BitStream instead of
a chart file or image.
Important Note: The getHtmlData Method "writes" the Chart directly to the response OuputStream by calling the getOutputStream() method, which will throw an exception if the getWriter() method is also called in the same servlet.
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