- ColdFusion Developers Guide
- Develop ColdFusion applications
- Introducing ColdFusion
- Changes in ColdFusion
- Changes in ColdFusion
- Replacement of JRun with Tomcat
- Security enhancements
- ColdFusion WebSocket
- Enhanced Java integration
- ColdFusion ORM search for indexing and search
- Solr enhancements
- Scheduler enhancements
- Integration with Microsoft Exchange Server 2010
- RESTful Web Services in ColdFusion
- Lazy loading across client and server in ColdFusion
- Web service enhancements
- Displaying geolocation
- Client-side charting
- Caching enhancements
- Server update using ColdFusion Administrator
- Secure Profile for ColdFusion Administrator
- Introduction to application development
- The CFML programming language
- Building blocks of ColdFusion applications
- Develop CFML applications
- Develop CFML applications
- Design and optimize a ColdFusion application
- Handle errors
- Use persistent data and locking
- Use ColdFusion threads
- Secure applications
- Client-side CFML (for mobile development)
- Use the ColdFusion debugger
- Debugging and Troubleshooting Applications
- Develop globalized applications
- REST enhancements in ColdFusion
- Authentication through OAuth
- Social enhancements
- Develop mobile applications
- Access and use data
- ColdFusion ORM
- ColdFusion and HTML5
- Flex and AIR integration in ColdFusion
- Request and present information
- Office file interoperability
- ColdFusion portlets
- Work with documents, charts, and reports
- Use web elements and external objects
- Use external resources
- Send and receive e-mail
- Interact with Microsoft Exchange servers
- Interact with remote servers
- Manage files on the server
- Use event gateways
- Create custom event gateways
- Use the ColdFusion extensions for Eclipse
- Use the data services messaging event gateway
- Use the data management event gateway
- Use the FMS event gateway
- Use the instant messaging event gateways
- Use the SMS event gateway
In some cases, your application could 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. Saving the variable on disk lets you create or update charts only as needed, rather than every time someone requests a page that contains a chart.
You use the name attribute of the cfchart tag to write a chart to a variable. If you specify the name attribute, the chart is not rendered in the browser but is written to the variable.
You can save the chart as an Adobe Flash SWF file, or as a JPEG or PNG image file. If you save the image as a SWF file, you can pass the variable back to a Flash client using ColdFusion Flash Remoting. For more information, see Using the Flash Remoting Service.
Note: If you write the chart to a JPEG or PNG file, mouseover tips and URLs embedded in the chart for data drill-down do not work when you redisplay the image from the file. However, if you save the image as a SWF file, both tips and drill-down URLs work. For more information on data drill-down, see Linking charts to URLs. |
Write a chart to a variable and a file
Create a ColdFusion page with the following content:
<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>
<cffile
action="WRITE"
file="c:\inetpub\wwwroot\charts\vehicle.jpg"
output="#myChart#">
<img src="/charts/vehicle.jpg" height=240 width=320>- Save the page as chartToFile.cfm in myapps under the web root directory.
- View the chartToFile.cfm page in your browser.
Reviewing the code
The following table describes the highlighted code and its function:
Code |
Description |
---|---|
<cfchart name="myChart" format="jpg"> |
Define a chart written to the myChart variable by using the JPEG format. |
<cffile action="WRITE" file="c:\inetpub\wwwroot\charts\vehicle.jpg" output="#myChart#"> |
Use the cffile tag to write the chart to a file. |
<img src="/charts/vehicle.jpg" height=240 width=320> |
Use the HTML img tag to display the chart.
|