Custom templates in Android Studio

Transcript

1. Custom templates in Android Studio @ Andrey Dotsenko / Shape DevDay / 28.08.2020
2. Plan - Types of templates in Android Studio - Live templates - File templates - Android component templates - How to create custom templates of each type - Some ideas about how to improve the development process with templates
3. What is template for?
4. Template types: - Live templates - File templates - Android component templates
5. Live templates
6. Live templates For insertion common constructs into your code, such as loops, conditions, various declarations etc. https://www.jetbrains.com/help/idea/using-live-templates.html
7. Types of live templates: - Simple templates - Parameterized templates - Surround templates
8. Simple live templates Contain only fixed plain text.
9. Parameterized templates Contain variables that enable user input. - Loops - If checks - Function declarations - Simple & common pieces of code
10. Toast
11. New Instance
12. Surround templates Wrap a block of the selected code ⌥ ⌘ J
13. Custom live template
14. Custom live template Go to Preferences | Editor | Live Templates
19. Result
20. Another example
21. File templates
22. File templates Default contents to be generated when creating a new file.
23. Custom File Template Go to Preferences | Editor | File and Code Templates
24. Predefined template variables ${DATE} ${FILE_NAME} ${PACKAGE_NAME} ${PROJECT_NAME} ... https://www.jetbrains.com/help/idea/file-template-variables.html
25. Apache Velocity Template Language
26. Custom file template available from menu
27. Custom variables
28. Custom variables
29. It’s ok but not impressive
30. Android component templates
31. A lot of templates for different Android components
32. Demo
33. Freemarker template engine - Java library to generate text output - Templates are written in the FreeMarker Template Language - Android-specific tooling and GUI in Android Studio
34. How to create custom component template? - Create template files according to Freemarker format - Place template files to ANDROID_STUDIO_DIR\plugins\android\lib\templates\ - Restart Android Studio
35. Why so “elegant”?
36. Unofficial Jedi way - No official support custom templates - Narrow & outdated documentation - Tricky debugging - But a lot of profit
37. Template structure - template.xml (required) - recipe.xml.ftl (required) - globals.xml.ftl - .ftl file for each file you’d like to generate - Image file with cat to show in template window
38. Template.xml - metadata
39. Template.xml - metadata - String input fields - Checkboxes (boolean) - Enums - Required / optional - Constraints (e.g. "class|nonempty|unique") - Dependency between items (name suggestion, visibility) - Modify user input (activityToLayout, classToResource) - Define recipe and globals files
40. globals.xml.ftl global variable definitions
41. .ftl files - actual template files
42. .ftl files - actual template files - Use variables from template.xml and globals.xml - Use power of Freemarker Template language - Built-in Android Template functions and parameters
43. Available android-specific functions & parameters
44. recipe.xml.ftl - instructions for Freemarker
45. recipe.xml.ftl - instructions for Freemarker - <instantiate> - <open> - <dependency> - <copy> - <merge> - <mkdir>
46. Whole template creation flow User selects template in Android Studio GUI with template configuration (template.xml) User completes and confirms configuration Freemarker executes recipe.xml.ftl Output files generated based on .ftl templates and user data on previous steps
47. What if something went wrong..?
48. Template debugging - Open Android Studio log (Help | Show log) - Find stacktrace and figure out what was wrong - Fix problem - Reboot Android Studio
49. Android Studio updates
50. Pros & cons Pros: - Super-flexible - Project-specific - Serve any custom or third-party solutions - From several files to whole project draft - Development process boost Cons: - Merge only for XML and Gradle - Unofficial way - Lack of documentation - Awkward debugging - Android Studio updates destroy all your fancy setup - No guarantees
51. Ideas for development process Cases: - Presentation layer (MVVM/MVP/MWhatever boilerplate, content/loading/error states management, data-binding lists initialization) - Domain layer structures (interactor, component etc) - Network layer (service, mapping, repository) - Custom views (class, declare-styleable, SavedState) - Gradle feature module with full initial setup - Module layout (Server Driven UI) - Draft project with all dependencies, base classes, DI setup etc ...
52. Ideas for development process Advantages: - “Forced” code/component style - Development speed acceleration - Boring stuff automatization - Reusable templates across projects
53. Links - IDEA help https://www.jetbrains.com/help/idea/using-file-and-code-templates.html https://www.jetbrains.com/help/idea/using-live-templates.html - Apache FreeMarker https://freemarker.apache.org/docs/ - Google Git folder with docs for Android Component Templates https://android.googlesource.com/platform/sdk/+/refs/heads/master/templates/doc s/ - Demo project https://github.com/dosssik/AndroidComponentTemplatesExample
54. Thank you!
55. Q & A