Notes from SymfonyOnline June 2023 - day 1

Keynote: The Scheduler Component - Fabien Potencier

• Scheduler is thin layer around existing Messenger Component infrastructure
• recurring messages are generated by special kind of messenger transport: scheduler is the transport
• generated messages are handled immediately, synchronously by default
• time of execution of the handlers influences time of handling later messages - beware: delays are possible
• adding jitter when configuring schedule is good idea: ->withJitter(seconds) - avoid CPU usage spikes
• recurring message is really like a ping that triggers a handler (think: thin event)
• redispatching messages to async transport - easy, supported, there is message wrapper for it
• consumer does all the work of generating and handling messages - transport naming convention: scheduler_<name_from_attribute>
• be careful about running multiple workers at the same time: duplication of messages may occur - use locks on schedule or message handling level
• stateful schedule - ->stateful(cache) - remembers when last message was generated, is able to "recover" / generate missed messages
• it does not map 1:1 to traditional cron, has similarities but is more flexible and integrated with the framework

Is SOLID dead? Let's discuss reusable software design - Łukasz Chruściel

• the answer: it is not
• SOLID vs. CUPID (link, link)
• types of classes: data structures, calculations (pure, impure), side effects (impure, external)
• in reusable software: think twice on using final classes (prefer interfaces, non-final classes), in non-reusable: it does not matter that much
• doctrine repository interface with 100 methods - what's the solution?

Optimize your software with API first - Maximilian Beckers

• presentation slides, original article
• first step: think about goals, design, do not code
• talk with owners, brainstorm, try to understand, design, only then fulfill the contract with implementation
• tools: miro, egon.io, domainstorytelling.org
• define contact using Open API spec - create YAML file, use vacuum, redoc
• Open API spec - not only for HTTP API (? - but also events / messages)
• generate mocks from Open API spec: prism, wiremock, wiremock-php
• implementation example, two repos:
  • one for spec only
  • second for implementation of the spec - contains partly auto-generated code from spec
  • use pull requests flow
• versioning, one (of many) ways:
  • version in path
  • different controllers / handlers per version
  • publish version only on BC breaks
• thephpleague/openapi-psr7-validator
• long YAML spec - just live with it
  • imports available from Open API spec v3 but not supported by tooling (yet)

Teaching Doctrine to be Lazy - Kevin Bond

• presentation slides
• hydration is expensive: control what you do, checklist:
  • what do I hydrate?
  • when do I hydrate?
  • am I doing cleanup?
• debesha/doctrine-hydration-profiler-bundle
• hooks that allow for doctrine/native visualization of hydration in SF profiler - maybe in the future
• ocramius/doctrine-batch-utils
  • BatchIterator, BatchProcessor - manage efficient iteration/processing of the data
  • makes memory usage stay the same - only execution time increases, 160+MB vs 20MB
• balance of hydration and num of queries - not always makes sense to optimize num of queries
• future ideas, tools for lazy and efficient collections: zenstruck/collection
• specification pattern

AssetMapper: Manage Your JS Deps Without Node - Kévin Dunglas

• SPAs as source of complexity
• strada - mobile hybrid apps solution from hotwire guys - not released yet
• symfony ux - cool but node.js, npm, webpack - makes stuff heavy
• native JS Modules to the rescue - splitting code into reusable modules that web browsers understand
• supported by all modern browsers, by node, good cache dynamics when using HTTP2+ multiplexing
• Import Maps spec
  • allows for substituting non-native module names (@turbo/whatever) to resolvable URLs
  • currently needs polyfill to work
  • allows for reusing npm (non non-native/commonjs js modules) in browser context
• Asset Mapper component - new SF component
  • tool like composer but for JS/CSS deps, can download modules locally, can use in-flight module conversion CDNs
  • embraces Import Maps spec
  • inspired by importmap-rails
  • importmap.php - main config file
  • limitations: not for SPA-like usage, currently not for JS/CSS preprocessors