Subsystems documentation

• Provisioning and third-party dependencies
  • Provisioning
    • PROVISION_VERSION
  • Philosophy on adding third-party dependencies
  • System packages
  • Python packages
    • Upgrading packages
  • JavaScript and other frontend packages
  • Node and Yarn
  • ShellCheck and shfmt
  • Puppet packages
  • Other third-party and generated files
    • Emoji
    • Translations data
    • Pygments data
  • Modifying provisioning
• Settings system
  • Server settings
    • Testing non-default settings
  • Realm settings
• HTML and CSS
  • Zulip CSS organization
  • Editing Zulip CSS
  • CSS style guidelines
    • Avoid duplicated code
    • Be consistent with existing similar UI
    • Use clear, unique names for classes and object IDs
  • Validating CSS
  • HTML templates
    • Behavior
    • Backend templates
    • Frontend templates
    • Toolchain
    • Translation
    • Tooltips
  • Static asset pipeline
    • Primary build process
    • Adding static files
    • How it works in production
    • ES6/TypeScript modules
• Real-time push and events
  • Generation system
  • Delivery system
  • The initial data fetch
    • Testing
    • Messages
  • Schema changes
• Sending messages
  • Message lists
  • Compose area
  • Backend implementation
  • Local echo
    • Local echo in message editing
  • Putting it all together
  • Message editing
    • Inline URL previews
  • Soft deactivation
• Notifications in Zulip
  • Important corner cases
  • The mobile/email notifications flow
• Queue processors
  • Adding a new queue processor
  • Publishing events into a queue
  • Clearing a RabbitMQ queue
• Unread counts and the pointer
  • Pointer logic
    • Recipient bar: message you clicked
    • Search, sidebar click, or new tab: unread/recent matching narrow
    • Unnarrow: previous sequence
    • Forced reload: state preservation
  • Unread count logic
  • Testing and development
• Markdown implementation
  • Testing
  • Changing Zulip’s Markdown processor
  • Per-realm features
  • Zulip’s Markdown philosophy
  • Zulip’s changes to Markdown
    • Basic syntax
    • Lists
    • Links
    • Code
    • Other
• Caching in Zulip
  • Backend caching with memcached
    • The core implementation
    • Cautions
    • Cache invalidation after writes
    • Production deployments and database migrations
    • Automated testing and memcached
    • Manual testing and memcached
    • Performance
  • In-process caching in Django
  • Browser caching of state
• Performance and scalability
  • Load profiles
  • Major Zulip endpoints
    • Tornado
    • Presence
    • Fetching page_params
    • Fetching message history
    • User uploads
    • Sending and editing messages
    • Other endpoints
  • Queue processors and cron jobs
  • Service scalability
• Realms in Zulip
  • Creating realms
    • Using unique link generator
    • Enabling open realm creation
  • Subdomains
    • Working with subdomains in development environment
• Management commands
  • Writing management commands
• Schema migrations
  • Automated testing for migrations
  • Schema and initial data changes
• URL hashes and deep linking
  • Hashchange
  • Server-initiated reloads
  • All reloads
• Emoji
  • Emoji codes
    • Custom emoji
  • Tooling
  • Picking emoji names
• Hotspots
  • Adding a new hotspot
    • Step 1: Create hotspot content
    • Step 2: Configure hotspot placement
    • Step 3: Test manually
    • Step 4 (if necessary): Tweak hotspot icon z-index
• Full-text search
  • The default full-text search implementation
  • Multi-language full-text search
    • Enabling PGroonga
    • Disabling PGroonga
• Email
  • Development and testing
    • Testing in a real email client
    • Notes
  • Email templates
• Analytics
  • Analytics backend overview
  • The *Count database tables
  • CountStats
  • The FillState table
  • Performance strategy
  • Backend testing
  • LoggingCountStats
  • Analytics UI development and testing
    • Setup and testing
    • Adding or editing /stats graphs
    • /activity page
• Clients in Zulip
  • Analytics
  • Integrations
• Logging and error reporting
  • Backend error reporting
    • Backend logging
  • Blueslip frontend error reporting
  • Frontend performance reporting
• Typing indicators
  • Writing user
  • Server
  • Receiving user
  • Ecosystem
  • Roadmap
• Upgrading Django
• Zulip server release checklist
  • A week before the release
  • Final release preparation
  • Executing the release
  • Post-release
• Zulip PyPI package release checklist
• UI: input pills
  • Setup
  • Basic usage
  • Typeahead
    • onPillCreate and onPillRemove methods
• Presence
• Unread message synchronization
• Billing
  • Upgrading Stripe API versions
• Widgets
  • What is a widget?
  • /me messages
  • Polls, todo lists, and games
    • Data flow
    • Backward compatibility
    • Adding widgets
  • zform (trivia quiz bot)
  • Data flow
• Slash commands
  • Data flow
  • Typeahead