Crystal Reports User Function Libraries

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Crystal ReportsUser Function Libraries

• Bruce Ferguson
• Chelsea Technologies Ltd
• A Presentation to the Auckland Visual Basic User
  Group, 28 April, 1999

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Chelsea Technologies Ltd

• Crystal Reports training
• Crystal Reports development
• Crystal Reports consulting
• VB development
• www.chelseatech.co.nz
• bruce_at_chelseatech.co.nz

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Visual Basic and Crystal Reports

• CR 4 distributed with VB
• Can design/modify reports
• database, ODBC, ADO, ACT, Outlook, servers
• License to distribute run time DLLs
• CRYSTL32.OCX object
• 200 properties and methods (usually use lt 6)
• Crystal API

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Versions of Crystal Reports

• Crystal Reports 5
• Sub reports, variables, crosstab objects, UFL
• Crystal Reports 6
• More functions, Group tree, Web integration
• Crystal Reports 7
• Running Totals, Maps, Parameters, Web services

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Crystal Formula Fields

• Calculations based on DB fields
• Extensive list of built in functions
• Numeric, string, date, time, boolean, ranges,
  arrays, summary, etc.

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Demonstration Simple Crystal Report
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But what if you want more...
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Complex Report Development

• Sub Reports
• Reports inside a report (linked/unlinked)
• Separate DB, formulas, format
• Variables
• Temporary storage
• Complex Ifthenelse
• Multi line formulas
• Can control evaluation time

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Crystal Reports Limitations

• Based around Database fields
• plus some special fields
• (print date, page number, page count, author,
  report filename, etc.)
• No loops, for.. next, do while, etc.
• No case statement
• Local to each report/sub report

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User Function Libraries

• You can write your own functions
• VB, Delphi, C
• Special formatting/data conversion
• Information not in the database
• Registry
• Disk volume information
• Text/Data files
• Other things - any suggestions?

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Why use UFL?

• Available to all reports/versions
• More efficient processing
• More powerful
• Can be placed in any section
• Customise your reports

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Writing a UFL

• Create a new VB project (ActiveX DLL)
• Create a new class
• Create a public function
• (numeric, date, string, etc.)
• Compile the DLL
• Register the DLL

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Naming the UFL

• Project file Name CRUFLxxx.DLL
• Project Name CRUFLnnn
• Class Name ccc
• Public Function Name fff
• UFL nnncccfff

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Demonstration
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Processing the UFL

• Report Header/Footer
• Page Header/Footer
• Group Header/Footer
• Details
• Sub Report

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Conclusion

• UFL are very powerful and easy to develop
• Available to all reports/versions
• More efficient/consistent processing
• More powerful
• Can be placed in any section of the report
• Customise your reports
• Any questions?