XML is Dead. Long Live XML! (IPC2013SE 2013-06-04)

Presentation given at International PHP Conference 2013 Spring Edition in Berlin, Germany.

Transcript

1. XML IS DEAD.
   LONG LIVE XML!
   

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2. David Zülke
   

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3. David Zuelke
   

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5. http://en.wikipedia.org/wiki/File:München_Panorama.JPG
   

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6. Lead Architect
   

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8. @dzuelke
   

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9. TODAY'S MENU
   • XML (and where it took a wrong turn)
   • HTML 5 (and why it makes me a little bit sad)
   • JSON (and why it's not as universally useful as you may think)
   • YAML (and why it makes my eyes bleed)
   

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10. but first
    

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11. I'd like to hear from you, dear audience
    

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12. what do you love, hate, adore or loathe with a passion?
    

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13. XML
    eXtensible Markup Language
    

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14. "extensible" mostly refers to the Namespaces concept
    and the document model
    

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15. READING AND WRITING
    • Push Parsing, uses events to notify app during parsing
    • Example: SAX
    • Pull Parsing, allows app to retrieve or skip elements
    • Example: PHP's ext/xmlreader
    • DOM, constructs an object representation of the tree
    • Example: DOM (duh)
    Use XMLReader::expand()
    

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16. VALIDATION
    • XML Schema (validates the grammar of a document)
    • RELAX NG (like XML Schema, just full of win)
    • Except it's so awesome it sucks at reporting errors :(
    • Schematron (validates the semantics of a document)
    • DTD (RRRRRRRAAAAAAAAAAAAAAAAAGGGGEEEE)
    

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17. OTHER GOODIES
    • XPath and XQuery for querying documents
    • XPath is an expression syntax, XQuery a full query language
    • XSLT to transform documents to XML, HTML, text, ...
    • Makes heavy use of XPath
    • XIncludes
    • Allow re-use of content within and across documents
    <3
    

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18. but most importantly
    

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19. XML’s document model is built for extensibility
    

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20. 
    
       
           Bacon
           5.99
       
    
    

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21. //p:product[1]/p:price[1]  =>  “5.99”
    “p” bound to “http:/
    /acme.com/shop/products”
    

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22. 
    
       
           Bacon
           5.99
           OMNOMNOM  Bacon
       
    
    

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23. 
    
       
           Bacon
           5.99
       
    
    

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24. 
    
       
           Bacon
           5.99
       
    
    

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25. //p:product[1]/p:price[1]  =>  “5.99”
    

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26. 
    
       
           Bacon
           5.99
           4.49
       
    
    

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27. //p:product[1]/p:price[1]  =>  “5.99”
    

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28. 
    
       
           Bacon
           Speck
           5.99
           4.49
       
    
    

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29. 
    
       
           Bacon
           Speck
           5.99
           
       
    
    

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30. XML: doing it right
    

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31. 
    
       6
       2
       1
                       rel="self"  title="self"/>
                       rel="next"  title="next"/>
                       rel="last"  title="last"/>
       
           true
           2003-­‐09-­‐12
           
           http://openapi.lovefilm.com/catalog/title/59643
           false
           574
           4
           
           
           
           
           
                               rel="http://schemas.lovefilm.com/synopsis"  title="synopsis"/>
                               rel="http://schemas.lovefilm.com/reviews"  title="reviews"/>
                               rel="alternate"  title="web  page"/>
       
    
    

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32. which brings me to...
    

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33. HATEOAS AND HYPERMEDIA
    The Main Ingredient For Your REST API
    

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34. XML: doing it wrong
    

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35. 
       "http://www.apple.com/DTDs/PropertyList-­‐1.0.dtd">
    
    
           DefaultProfileChoices
           
                   AC  Power
                   2
                   Battery  Power
                   1
                   UPS  Power
                   1
           
           SystemProfileDefaults
           
    
                   
    
                           AC  Power
                           
                               
                           
                   
           
    
    
    

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36. but please
    do not serialize objects to XML
    (I'm looking at you, SOAP)
    

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37. HTML 5
    Such a mess :(
    

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38. HTML 5
    • Neither SGML nor XML
    • so browser vendors need to write new (inefficient) parsers
    • Does not have a DTD anymore
    • how could it, given how it's not SGML...
    • Completely idiotic stuff like data-* attributes
    • And they're even proud of it...
    

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39.          data-­‐name="John  Resig"  data-­‐city="Boston"
             data-­‐lang="js"  data-­‐food="Bacon">
       John  says:  Hello,  how  are  you?
    
    

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40. but that's already possible in XML!
    

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41.          xmlns:myapp="http://myapp.com/v1"
             myapp:name="John  Resig"  myapp:city="Boston"
             myapp:lang="js"  myapp:food="Bacon">
       John  says:  Hello,  how  are  you?
    
    

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42. JSON
    JavaScript Object Notation
    

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43. JSON KEY FEATURES
    • Quite efficient, simple, universally supported in many languages
    • Very good for serializing objects
    • Built-in types, do not need explicit declaration
    • No schemas
    • No mixed content
    

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44. win: store arbitrary keys and values
    

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45. {
           "_id"  :  "bc2a41170621c326ec68382f846d5764",
           "_rev"  :  "2612672603",
           "item"  :  "orange",
           "prices"  :  {
                   "Fresh  Mart"  :  1.99,
                   "Price  Max"  :  3.19,
                   "Citrus  Circus"  :  1.09
           }
    }
    

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46. fail: use it as query language for your “web scale” database
    

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47. {  foo:  "bar"  }
    {  x  :  3,  y  :  "foo"  }
    {  $or  :  [  {  a  :  1  }  ,  {  b  :  2  }  ]  }
    {  j  :  {  $ne:  3  },  k  :  {  $gt:  10  }  }
    {  x  :  3  },  {  z  :  1  }
    {  j  :  {  $in  :  [2,4,6]  }  }
    {  "author.name"  :  "joe"  }
    {  "addresses.city"  :  "London"  }
    

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48. EVOLVABILITY
    Because Things Change Over Time!
    

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49. 
    
       1234
       Red  Stapler
                                 href="http://acme.com/products/1234/payment"/>
       3.14
    
    {
       id:  1234,
       name:  "Red  Stapler",
       links:  [
           {
               rel:  "payment",
               type:  "application/vnd.com.acme.shop+json",
               href:  "http://acme.com/products/1234/payment"
           }
       ],
       price:  3.14
    }
    XML VERSUS JSON
    

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50. 
    
       1234
       Red  Stapler
                                 href="http://acme.com/products/1234/payment"/>
       3.14
    
    {
       id:  1234,
       name:  "Red  Stapler",
       links:  [
           {
               rel:  "payment",
               type:  "application/vnd.com.acme.shop+json",
               href:  "http://acme.com/products/1234/payment"
           }
       ],
       price:  {
           amount:  3.14,
           currency:  "EUR"
       }
    }
    XML VERSUS JSON
    Content (“node value”) still the same
    Float becomes object, stuff breaks
    

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51. YAML
    Yet Another Markup Language
    

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52. YAML
    Yet Another Markup Language
    YAML Ain't Markup Language
    

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53. recursive acronyms are cool
    

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54. YAML also was cool at some point
    

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55. a simple markup language, perfect for configuration files
    

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56. autoload:
       #  plugins
       plugins_lib:
           name:                      plugins  lib
           path:                      %SF_PLUGINS_DIR%/*/lib
           recursive:            true
           exclude:                []        
       plugins_module_lib:
           name:                      plugins  module  lib
           path:                      %SF_PLUGINS_DIR%/*/modules/*/lib
           prefix:                  2
           recursive:            true
           exclude:                []
       #  project
       project:
           name:                      project
           path:                      %SF_LIB_DIR%
           recursive:            true
           exclude:                [model,  symfony,  deprecated]
    

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57. but then...
    

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58. foo:  |  
           -­‐-­‐-­‐
           foo:  bar
           -­‐-­‐-­‐
           yo:  baz
    bar:  |  
           fooness
           
    clipped:  |
           This  has  one  newline.
    same  as  "clipped"  above:  "This  has  one  newline.\n"
    stripped:  |-­‐
           This  has  no  newline.
    same  as  "stripped"  above:  "This  has  no  newline."
    kept:  |+
           This  has  four  newlines.
    same  as  "kept"  above:  "This  has  four  newlines.\n\n\n\n"
    -­‐  &showell  Steve
    -­‐  Clark  
    -­‐  Brian  
    -­‐  Oren  
    -­‐  *showell
    

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59. YAML DRAWBACKS
    • Makes your eyes bleed
    • No schemas or other forms of validation
    • Forget a newline somewhere and the parser might look at
    you, helpless, like a deer in headlights
    • No mixed content
    

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60. CONCLUSION
    • XML for hypermedia, documents, your new REST API
    • JSON for serializing objects and storing them in e.g. CouchDB
    • YAML for your configuration files
    

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61. !e End
    

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62. Questions?
    

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63. THANK YOU!
    This was http://joind.in/8809
    by @dzuelke
    Questions? E-Mail:
    dz@europeanmedia.com
    

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