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

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

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

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

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

“need” is considered harmful

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

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

Model Interviews https://lemmalegal.com/2019/06/17/designing-docassemble-interviews-for-maintainability-start-to-finish/

2. Code with Style

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

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

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

Variable Name Standards https://bit.ly/2IkW7mz (Michelle from Code for Boston) On Slack: #structuring-code

3. Divide and Conquer

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

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

4. Get your edit on

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

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

5. Objectify your life

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

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

Built-in classes to understand: Individual Address Date DAList

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

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

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)

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

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