1. Designing Docassemble Interviews for Maintainability
Quinten Steenhuis, Founder, Lemma Legal Consulting
@QSteenhuis

3. Why care? Write code your future self can follow Speed up development
Make your life easier

4. When does it matter? When your interview is “big enough”
You start to get frustrated with navigating around it

5. “
Premature optimization is the root of all evil ”
Donald Knuth

6. 5 Basic Techniques Manage control flow in one place
Use good coding style
Use the “right” number of interview files
Use the right editor
Use object-oriented principles

7. “need” is considered harmful

9. Interview Flow Control
Use one mandatory code block to control program flow
Give the code block an ID
Use only simple branching logic in the control block

10. Use one control block One place to look to understand program flow
Easily change the order of questions
Easily test different questions that don’t depend on earlier questions

11. Model Interviews

12. 2. Code with Style

13. Using “good” coding style
Use the id tag to label questions and code
Use the variable name standards
Use comments

14. Tag your blocks Easy to find the question you need
Needed for Google Analytics
Aid in translation
Aid in debugging

15. “
The nice thing about standards is that you have so many to choose from ”
Andrew Tannenbaum

16. Variable Name Standards
(Michelle from Code for Boston)
On Slack: #structuring-code

17. 3. Divide and Conquer

18. Why do you need a separate interview file?
Question reuse
Translation (old style only)
Multiple simultaneous authors
Interview file is just “too long”

19. Use the right number of interview files
Start with 1
Separate reusable questions
Keep a skeleton interview with control flow
Keep related questions/code together, but take advantage of search

20. 4. Get your edit on

21. Some popular (free) editors
VS Code
Atom
Notepad++
Emacs? ViM?

22. Using an external editor
Plain text means you choose the editor
Better search/replace
Code completion
Split screen view

28. 5. Objectify your life

29. Why use Classes / OOP? Make your code readable
Use advanced Docassemble features
Make your code more modular and reusable
Simplify your interviews
Write idiomatic code

30. Object oriented classes
Create once and use again
Build iteratively
Hide implementation details

33. Built-in classes to understand:
Individual
Address
Date
DAList

34. Built-in classes are used in
send_ (), send_sms()
map_of()
Pronouns/age functions
Collective/singular tense matching

35. Start here: https://bit.ly/2wSTTVd
Are classes easy?
Truthfully, no. But it’s worth learning the basics.
Start here:

36. A common pattern: DAObject and DAList
Asset / AssetList
Individual / Individual List
3-4 attributes, a collection, and one-two methods that count or act on the attributes (such as sum)

37. Common Pattern #2: API query
Constructor that uses the Docassemble configuration to get an API key
A getter for each type of item retrievable by the API
A setter
Extend over time as you use more of the API

38. Quinten Steenhuis, Lemma Legal @QSteenhuis
Questions?
Quinten Steenhuis, Lemma Legal
@QSteenhuis