Small Things | Loosely Joined
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The document outlines a presentation by Dr. Don Levan at the 2010 FileMaker Developer Conference, focusing on programming efficiency, code reuse, and error management. Key concepts include the importance of compact, transparent code, the benefits of loosely joined programming, and the need to separate data from program logic. It features case studies and practical examples to illustrate these principles, emphasizing a pragmatic approach to software development.
Small Things | Loosely Joined
- 1. FileMaker Developer Conference 2010 Session COR010 Small Things | Loosely Joined Lessons Learned to Improve Quality, Reuse Code, and Program Efficiently) Dr. Don Levan Vanguard Custom Software
- 2. Who am I? President, Vanguard Custom Software FileMaker 7, 8, 9, 10 Certified Developer Licensed Clinical Psychologist Former Photojournalist Founder of the Craft of FileMaker Seminar Series 2
- 3. Please See the handout (on the CD): vanguardcs.net/devcon You will find: Summary of the problem Key points References Information about the Craft of FileMaker Seminar Series
- 4. A Story about Craft.
- 8. Small Things | Loosely Joined
- 9. Small Things | Loosely Joined Fail Loudly
- 10. Small Things | Loosely Joined Fail Loudly Fold Knowledge into Data
- 11. Case Study: Tekserves Payment Routines (With Technical Debt)
- 12. Small Things | Loosely Joined
- 13. Small Things: Are compact, transparent, and do one thing well.
- 14. Small Things: Are compact, transparent, and do one thing well.
- 15. Small Things: Are compact, transparent, and do one thing well.
- 16. DECREASING TRANSPARENCY: BY NESTING IFS
- 17. INCREASING TRANSPARENCY: BY REFACTORING
- 18. DECREASING TRANSPARENCY: BY EXITING LATE
- 19. INCREASING TRANSPARENCY: BY REFACTORING
- 20. INCREASING TRANSPARENCY: BY NAMING WELL Field Names: Lowercase and underscore. No punctuation other than underscore. No Periods. No spaces. Boolean: Use a form of the verb to be or to have, such as is_customer or has_children. Example: first_name Tekserve FileMaker & MySQL Conventions (2009)
- 21. INCREASING TRANSPARENCY: BY NAMING WELL Variable Names: Use a name that clearly communicates intent. Follow the convention for field names. Example: $report_type Tekserve FileMaker & MySQL Conventions (2009)
- 22. INCREASING TRANSPARENCY: BY NAMING WELL Script Names: Name scripts to describe their purpose. Use active voice. Add a parenthesis to indicate any parameters. Example: Process payment ( entry; type; action) Tekserve FileMaker & MySQL Conventions (2009)
- 23. SMALL THINGS: DO ONE THING WELL The Unix Pipe: $ program_1 | program_2 | program_3
- 24. SMALL THINGS: DO ONE THING WELL The Unix Pipe: $ history | grep ssh -p
- 25. Loosely Joined programs: Keep it dry, shy, and tell the other guy. Andy Hunt and Dave Thomas, IEEE Software 2000
- 26. LOOSELY JOINED PROGRAMS: Do not repeat themselves (Dry). Keep their variables as local as possible (Shy). Break complex scripts into disconnected layers. Pass in the data (Tell the other guy). Expect the output of any script to be used by another.
- 27. LOOSELY JOINED PROGRAMS: UNIX PIPES All Unix programs have multiple streams of information: Standard Input Standard Output Standard Error The pipe connects the Standard Output of one program to the Standard input of another.
- 28. LOOSELY JOINED PROGRAMS: FILEMAKER PIPES Unix FileMaker Standard Input Get (ScriptParameter) Standard Output Get (ScriptResult) Standard Error Get (ScriptResult)
- 29. LOOSELY JOINED PROGRAMS: FILEMAKER PIPES Main Script ( param_1; param_2) Set up variables Sub-Script ( param_1 ) Perform Script (pass parameters) Return error & output Set Variables to error and output Sub-Script ( param_1 ) Perform Script (pass parameters) Return error & output Set Variables to error and output Exit Script (Return error & output)
- 30. Small Things | Loosely Joined Case Study: Tekserves Payment Routines (Re-factored)
- 31. Small Things | Loosely Joined
- 32. Small Things | Loosely Joined Fail Loudly
- 33. Fail Loudly, and as soon as possible.
- 34. or, Dead scripts tell no lies. The Pragmatic Programmer, From Journeyman to Master
- 36. Capturing Errors
- 38. Returning Errors
- 39. Logging Errors
- 40. Logging Errors
- 41. Logging Errors
- 42. Logging Errors
- 43. Small Things | Loosely Joined Fail Loudly
- 44. Small Things | Loosely Joined Fail Loudly Fold Knowledge into Data
- 45. Fold Knowledge into Data so program logic can be stupid and robust.
- 46. FOLD KNOWLEDGE INTO DATA Differentiate between data and program logic. Separate the data out into script parameters, custom functions, and table records. Use SetFieldByname, Evaluate, and other functions to simplify script logic.
- 47. Fold Knowledge into Data Case Study: Creating child portal records.
- 48. Fold Knowledge into Data Case Study: Creating flexible reports
- 49. Fold Knowledge into Data Case Study: Synchronizing FileMaker and MySQL
- 50. Small Things | Loosely Joined Fail Loudly Fold Knowledge into Data
- 51. Small Things | Loosely Joined Fail Loudly Fold Knowledge into Data
- 52. Small Things | Loosely Joined Fail Loudly Fold Knowledge into Data
- 53. The only way to write complex software that wont fall on its face is to hold its global complexity down build it out of simple parts connected by well-defined interfaces, so that most problems are local and you can have some hope of upgrading a part without breaking the whole. The art of Unix Programming (p. 14)
- 54. FileMaker Developer Conference 2010 Web Update Page www.filemaker.com/devcon/speaker_updates (This is also listed in your conference binder) This session WILL / WILL NOT have updates.
- 55. Thank You! Please remember to fill out your evaluation at: www.filemaker.com/ devcon/evaluations
Editor's Notes
- #3: Introduction
- #5: 13 Magazine Ad - Eddie Adams Work with John Walther. My craft as a photographer Next: Same process as a programmer.
- #6: Main Problems: Everything is always changing. Life, business, economy, environment. Software must bend or break. We are limited: Memory 7 +/- 2. One Locus of Attention Systems are inherently interconnected. We are ill equipped to deal with complexity. - Gets big, then it gets buggy.
- #7: Started looking - Found Pragmatic Programmer Led to Ruby, Rails, then Unix.
- #8: Found that Generations of hackers and scientists had already solved the main problems. How to deal with change? how to deal with our limitations? how to keep systems form being overly coupled or connected? The most relevant of those traditions to FileMaker is Unix.
- #9: How do you do it: How do you create systems that achieve the goals of the moment and are able to adapt to new needs and challenges.
- #11: We are going to examine each of these points, looking at the philosophies and practices of others.
- #12: HIred by Tekserve to Convert their 20 year system to 9 6 Months. Next up, rewrite the payment system. Old and ossified. Unable to change. Holding back the business. SHOW ONLY THE SAMPLE FILE WITH TECHNICAL DEBT
- #55: Keep this slide at the end of your presentation. (Don't forget to remove this comment from the slide.)
- #56: Keep this slide at the end of your presentation. (Don't forget to remove this comment from the slide.)