apidays Paris 2022 - From API specifications to code with OpenAPI, Beppe Catanese, Adyen

apidays Paris 2022 - APIs the next 10 years: Software, Society, Sovereignty, Sustainability
December 14, 15 & 16, 2022

From API specifications to code with OpenAPI
Beppe Catanese, Developer Advocate at Adyen
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Transcript

1. From API specifications to
   code with OpenAPI
   
   
   

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2. 2023 SERIES OF EVENT
   New York
   May 16&17
   Australia
   October 11&12
   Singapore
   April 12&13
   Helsinki & North
   June 5&6
   Paris
   SEPTEMBER
   London
   November
   15&16
   June 28-30
   SILICON VALLEY
   March 14&15
   Dubai & Middle East
   February 22&23
   

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3. The API economy is on fire 🔥
   
   
   OpenAPI to the rescue 💦
   

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4. Developer Experience
   
   
   Code generation
   
   
   Adyen way of APIs
   
   
   OpenAPI
   
   
   Agenda
   

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5. Developer Advocate
   Me
   @beppecatanese
   gcatanese
   

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6. Adyen
   Financial technology
   Large merchants
   
   
   and marketplaces 3 technical hubs
   

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7. OpenAPI “Lingua Franca”
   
   
   Wordnik, Swagger
   
   
   OpenAPI initiative
   
   
   Code generation
   
   
   Validator
   
   
   Diff
   
   
   OpenAPI & OpenAPI Generator
   

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8. Client Server 100+ languages Configuration Documentation
   CLI Docker Jar Maven Gradle
   Code generation
   

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9. The Adyen way
   

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10. API Explorer
    

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11. From specs to code
    openapi: 3.0.0
    
    
    info:
    
    
    title: My API specs
    
    
    paths:
    
    
    ‘/users/{userId}’
    
    
    parameters:
    
    
    name: userId
    
    
    in: path
    
    
    …
    
    
    get:
    
    
    summary: Get User by ID
    
    
    responses:
    
    
    `200`:
    
    
    content:
    
    
    application/json:
    
    
    …
    
    
    components:
    
    
    schemas:
    
    
    User:
    
    
    ….
    OpenAPI generator
    Language? Framework?
    Source Code Templates
    Client? Server? Doc?
    

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12. From specs to Go client
    openapi-generator-cli generate -i SampleProject.yaml \
    -g go -t tmp/templates -p packageName=User -o tmp/gocodegen
    Demo or not demo?
    

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13. SDK developer workflow
    Generate Release Repeat
    

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14. • Logic-less
    
    
    • Source code, config, documentation
    
    
    • Tags: variables, sections, lists
    Mustache templates
    Separation of concerns done right
    

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15. Hello {{name}}
    Mustache template variable
    {
    
    
    “name”: “Beppe”
    
    
    }
    (template)
    (data)
    Hello Beppe
    

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16. {{#param}}
    
    
    if {{#name}} != null {
    
    
    // do something
    
    
    }
    
    
    {{/param}}
    Mustache template section tag
    {
    
    
    “param”:
    
    
    {“name”:”city”}
    
    
    }
    (template)
    (data)
    if city != null {
    
    
    // do something
    
    
    }
    

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17. {{#allParams}}
    
    
    {{type}} p{{name}},
    
    
    {{/allParams}}
    Mustache template list
    [
    
    
    {“type”: “String”, “name”: “City”},
    
    
    {“type”: “String”, “name”: “Country”}
    
    
    ]
    (data)
    String pCity, String pCountry,
    (template)
    

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18. Fetch templates
    openapi-generator-cli author template -g spring \
    -o tmp/myspringtemplate
    Demo or not demo?
    

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19. From specs to Java service
    openapi-generator-cli generate -i SampleProject.yaml -g spring \
    -p apiPackage=com.adyen.api -p modelPackage=com.adyen.model \
    -p groupId=com.adyen -p artifactId=MySampleApp -p artifactVersion=v0.1 \
    -p invokerPackage=com.adyen -p con
    fi
    gPackage=com.adyen.con
    fi
    guration \
    -o tmp/javacodegen
    Demo or not demo?
    

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20. Practices
    (re)Generate code
    Generate models
    
    
    and/or services
    Skip files
    

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21. Challenges
    Specs evolve Templates change Manual changes
    

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22. Developer Experience
    
    
    github.com/adyen
    
    
    github.com/adyen/adyen-openapi
    Final thoughts
    

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23. Thank You!
    

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