This is a low-level, and philosophical discussion on the act of compiling data out of your PHP applications using Zend\Code: Scanning, Generating, Annotating code in PHP.

1. October 2011
Skynet in ZF 2.0
Or, better put “what one can do with ZendCode”

2. Who Am I?
•Ralph Schindler (ralphschindler)
Software Engineer on the Zend Framework team
•At Zend for almost 4 years
•Before that TippingPoint/3Com
Programming PHP for 13+ years
Live in New Orleans, LA.
•Lived in Austin, Tx for 5 years
2

3. Why Skynet?
•From wikipedia:
“ ... an artificially intelligent system which
became self-aware and revolted against its
creators.”
“The strategy behind Skynet's creation was to
remove the possibility of human error and slow
reaction time to guarantee fast, efficient response
to enemy attack.”
3

4. Why Skynet?
•So, ... who is the enemy?
4

5. Why Skynet?
•Other enemies (without photo’s)
Unmaintainable applications
Untestable applications
Slow applications
Un-fun / boring code
Painful code
5

6. Why Skynet?
•So, what does Skynet look like?
•Anything we develop that looks
too magical
too-good-to-be-true
too all-encompassing
too flexible / too many input types
requires too much documentation
is outside our normal understanding of how things
work
6

7. Why Skynet?
•What does Skynet not look like?
Simple
Easy to understand
Finite inputs / outputs
Easy to get up and running with
7

8. Why Skynet
•In a nutshell: PHP
PHP has no development time compile phase
On it’s own, it doesn’t know much
•Hence, the many upon many frameworks
All decisions are pushed into “request” time
Single strategy for performance increase
•caching
•black-box optimizer
8

9. Why Skynet?
•Basically, ZendCode is Skynet (figuratively)
it can understand your code, sometimes better
than the developer whom wrote it
it can expose information about your code that the
developer was unaware of
it can generate code faster than you can
9

10. Why Skynet?
•Ok, not really
•ZendCode will not:
see developers as a threat
attempt to take over the world
send the Terminator (a.k.a Matthew Weier
O’Phinney) after you for writing bad,
unmaintainable, code
10

11. Who is the Terminator?
11

12. What does ZendCode Do?
•So, what does ZendCode do?
12

13. Let’s Recap the Humble Beginnings
•ZF1 users wanted scaffolding & RAD
•So, ...
Zend_Tool
•Zend_Tool_Project / Zend_Tool_Framework
Zend_CodeGenerator
•original intention was more than PHP
Zend_Reflection
•added docblock parsing functionality
13

14. ZF1 Problem Area
•This setup suffered from 2 major problems:
Runtime dependencies are not always loaded
Same request changes to structures do not update
in-memory structures
14

15. Problem 1
15

16. Problem 2
•Workflow (in the same request):
Require File
Build ZendCodeGenerator object based off Zend
Reflection object of a class
•(For example a controller)
Add method to class
Write to disk
Build ZendCodeGenerator object based off Zend
Reflection object
•FAIL! B/c file is already in memory
16

17. Problem 2 - Temporary Solution
•Temporary solution was to cache generator
objects that were built based one particular
reflection objects, and return those when asked
for a generator object seeded with a known
reflection object
•“We’ll fix this in ZF2”
17

18. Other Realizations
•We were not going to get other generator types
•Generators were closely related to Reflection
and the new Scanner component
•ZendCode was a better place for all of this
18

19. Static vs. Dynamic
•Runtime
Static - Fast
Dynamic - Slow
•Dev-time
Static - slower workflow
Dynamic - workflow resembles runtime
19

20. Static vs. Dynamic
•Typical PHP workflow for dynamic applications:
initiate request
fulfill request
return to consumer
20

21. Static vs. Dynamic
•Typical PHP workflow for “static” applications
with compilation built in (dev time):
initiate request
compile (during request, but omitted during production)
fulfill request
return to consumer
21

22. Static vs. Dynamic
•Typical PHP workflow for “static” applications
with compilation NOT built in (dev time):
(change code)
(compile code)
initiate request
fulfill request
return to consumer
22

23. Static vs. Dynamic
•You’ve probably seen static analysis in some way before:
Caching
•If you never intend on expiring the data, it’s not really a cache
if (!file_exists(..)) { file_put_contents(..., var_export()) }
Zend Optimizer / APC
Content Platforms:
•Drupal
– development mode
– non-caching mode
– module initialization
•Wordpress
– installation hooks: plugin initialization
23

24. What are we compiling?
•Anything dynamically looked up
What the valid routes are
What the valid application assets are
•classes
•view scripts
Where particular classes are located
More?
•Which extensions are loaded
•What the php environment can support
24

25. So, What Is Our Toolset?
•ZendCode
ZendCodeReflection
ZendCodeGenerator
ZendCodeScanner
ZendCodeAnnotation
25

26. ZendCodeReflection
•Originally part of ZF1
•Added features:
file reflection
docblock reflection
26

27. ZendCodeReflection
27

28. ZendCodeReflection cont’
28

29. ZendCodeGenerator
•Originally ZF 1’s ZendCodeGenerator
•Built OO Classes with an OO API
Mainly consumed by Zend_Tool
29

30. ZendCode
Generator
30

31. ZendCodeScanner
•ZendCodeScanner
Token based “reflection”
Reflection for files in ZF1 has a similar approach
Ascertain information in files:
•what namespaces are inside this file
•what use statements are inside a particular namespace
•what classes are in this file’s namespaces
•what files are required (none, right?)
•is there a file level docblock
31

32. ZendCodeScanner Class Hierarchy
32

33. ZendCode
Scanner (Sample)
33

34. ZendCodeAnnotation
•Annotations
Why? You asked for it. At least some of you did.
There’s no native PHP support for it
Similar to:
•Java’s Annotation system
•C#’s Attribute system
•Doctrine’s Annotation system
•with a PHP twist of course
34

35. ZendCodeAnnotation
•Design:
Do not force content into a particular DSL
Build as a simple easy to use framework for easy consumption
Prototype pattern
Use ZendCodeScanner
•Drawbacks
Slow, very very slow
35

36. ZendCodeAnnotation
•Single Interface to implement:
ZendCodeAnnotationAnnotation
36

37. ZendCodeAnnotationManager
•Simple Manager to Populate:
37

38. Demo 1: ZendCodeScanner
•Find all dependencies in a directory full of code
•Demo
38

39. Demo 2: Built a Micro-framework
•Goals
Find on github.com/ralphschindler/middlewarephp
few classes - the “middleware” is editable
fast (2ms request for hello world)
compilation based
•Routes
•Classmap autoloader
annotation based
utilize include returns, closures, and arrays
•Demo
39

40. Philisophical
•Let’s get philosophical:
Should we be “compiling” elements?
•Is this what PHP is all about?
•Rasmus says yes.
Can we architect flexible and performant
applications without some kind of static code
analysis that affects runtime?
How do we introduce these tasks into developer
workflows where they make the most sense, don’t
impede development?
40

41. Fin
•Questions and/or comments, let’s go grab a beer discuss.
•Remember ZF2 is only beta, if you have opinions on how we
should go about applying these techniques, get involved NOW!
•Thank you!
41