Writing A Chart To A Variable - MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX Develop Manual

<cfchartseries
type="bar"
query="DeptSalaries"
valueColumn="AvgByDept"
itemColumn="Dept_Name"
seriesColor="gray"
paintStyle="plain"
seriesLabel="Dept. Average Salaries"
/>
</cfchart>
Save the page as chart2queries.cfm in myapps under the web root directory. For example, the
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directory path on Windows might be C:\Inetpub\wwwroot\myapps.
Return to your browser and enter the following URL to view chart2queries.cfm:
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http://127.0.0.1/myapps/chart2queries.cfm

Writing a chart to a variable

In some cases, your application might have charts that are static or charts that, because of the
nature of the data input, take a long time to render. In this scenario, you can create a chart and
write it to a variable.
Once written to a variable, other ColdFusion pages can access the variable to display the chart, or
you can write the variable to disk to save the chart to a file. This lets you create or update charts
only as needed, rather than every time someone requests a page containing a chart.
You use the name attribute of the
name attribute, the chart is not rendered in the browser but is written to the variable.
You can save the chart as a Flash movie (.swf file), or as a JPG or PNG image file. If you save the
image as a Flash movie, you can pass the variable back to a Flash client using ColdFusion Flash
Remoting. For more information, see
on page 641.
Note: If you write the chart to a JPG or PNG file, mouseover tips and URLs embedded in the chart for
data drill-down will not work when you redisplay the image from the file. However, if you save the
image a Flash movie, both tips and drill-down URLs will work. For more information on data drill-
down, see "Linking charts to URLs" on page
To write a chart to a variable and a file:
Create a new ColdFusion page with the following content:
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<cfchart
name="myChart"
format="jpg"
>
<cfchartseries type="pie">
<cfchartdata item="New Vehicle Sales" value=500000>
<cfchartdata item="Used Vehicle Sales" value=250000>
<cfchartdata item="Leasing" value=300000>
<cfchartdata item="Service" value=400000>
</cfchartseries>
</cfchart>
tag to write a chart to a variable. If you specify the
cfchart
Chapter 29, "Using the Flash Remoting Service,"
636.
Charting data 627