Reacting to Change - API Days 2014

Transcript

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   REACTING TO CHANGE ! KYLE FULLER

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   BUILDING better API CLIENTS

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   None
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   None
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   DOZENS of APPS

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   HTTP / APIS

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   THERE’S AN API

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   COMPONENTS OF AN API CLIENT

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   perform(.RetrieveArticles) { result in switch result { case .Success(let representor):

   /* We've got some articles */ case .Error(let error): /* We hit an error */ } }
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    FOUNDATION

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    NSURLSession OR NSURLConnection

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    NSURLRequest

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    NSURLHTTPResponse

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    SIMPLE...

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    HTTP SEMANTICS

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    SERIALISATION (JSON)

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    CONVERT to VALUE-MODELS

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    struct Article { let title:String let body:String let author:Author let

    image:[NSURL] } struct Author { let name:String let twitter:String }
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    articles[0]["author"]["name"]

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    "/articles"

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    "name"

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    "nme"

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    - age + birthday

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    None
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    None
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    MAPPING

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    HTTP JSON MODEL MAPPING TESTS (STUBS & FIXTURES) DOMAIN LOGIC?

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    $ cloc **Model**.{h,m} **API**.{h,m} 95 text files. 83 unique files.

    0 files ignored. ------------------------------------------------------------------------------- Language files blank comment code ------------------------------------------------------------------------------- Objective C 51 1420 499 5598 C/C++ Header 32 258 480 479 ------------------------------------------------------------------------------- SUM: 83 1678 979 6077 -------------------------------------------------------------------------------
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    6077 LINES OF CODE

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    ANDROID

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    15,000 LINES OF CODE

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    WINDOWS PHONE

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    20,000 LINES OF CODE

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    ...

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    30,000 LINES OF CODE

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    BUILDING an API CLIENT

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    DOMAIN-SPECIFIC

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    INTEGRATED

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    MIXING PROTOCOL SEMANTICS

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    WHAT DOES THE API LOOK LIKE?

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    None
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    None
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    None
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    GETTING STARTED

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    TESTS

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    MOCK

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    [OHHTTPStubs stubRequestsPassingTest:^BOOL(NSURLRequest *request) { return ([request.URL.host isEqualToString:@"trunk.cocoapods.org"] && [request.URL.path isEqualToString:@"/api/v1/sessions"]);

    } withStubResponse:^ OHHTTPStubsResponse *(NSURLRequest *request) { NSString *fixture = OHPathForFileInBundle(@"sessions.json", nil); NSDictionary *headers = @{ @"Content-Type": @"application/json" }; return [OHHTTPStubsResponse responseWithFileAtPath:fixture statusCode:200 headers:headers]; }];
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    { "created_at": "2014-04-21 23:08:00 +0200", "email": "kyle@cocoapods.org", "name": "Kyle Fuller",

    "sessions": [ { "created_at": "2014-05-04 15:20:19 +0200", "valid_until": "2014-09-09 15:20:19 +0200", "verified": false }, { "created_at": "2014-05-04 15:20:20 +0200", "valid_until": "2014-09-09 15:20:20 +0200", "verified": true } ] }
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    AND REPEAT

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    None
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    CAN’T WE USE THIS?

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    UNDERSTANDABLE by machines

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    POWERING YOUR TESTS with API BLUEPRINT

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    pod `CCLRequestReplay`

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    [OHHTTPStubs stubRequestsPassingTest:^BOOL(NSURLRequest *request) { return ([request.URL.host isEqualToString:@"trunk.cocoapods.org"] && [request.URL.path isEqualToString:@"/api/v1/sessions"]);

    } withStubResponse:^ OHHTTPStubsResponse *(NSURLRequest *request) { NSString *fixture = OHPathForFileInBundle(@"sessions.json", nil); NSDictionary *headers = @{ @"Content-Type": @"application/json" }; return [OHHTTPStubsResponse responseWithFileAtPath:fixture statusCode:200 headers:headers]; }]; [OHHTTPStubs stubRequestsPassingTest:^BOOL(NSURLRequest *request) { return ([request.URL.host isEqualToString:@"trunk.cocoapods.org"] && [request.URL.path isEqualToString:@"/api/v1/pods"]); } withStubResponse:^ OHHTTPStubsResponse *(NSURLRequest *request) { NSString *fixture = OHPathForFileInBundle(@"pods.json", nil); NSDictionary *headers = @{ @"Content-Type": @"application/json" }; return [OHHTTPStubsResponse responseWithFileAtPath:fixture statusCode:200 headers:headers]; }]; [OHHTTPStubs stubRequestsPassingTest:^BOOL(NSURLRequest *request) { return ([request.URL.host isEqualToString:@"trunk.cocoapods.org"] && [request.URL.path isEqualToString:@"/api/v1/pod/../owners"]); } withStubResponse:^ OHHTTPStubsResponse *(NSURLRequest *request) { NSString *fixture = OHPathForFileInBundle(@"pod-querykit-owners.json", nil); NSDictionary *headers = @{ @"Content-Type": @"application/json" }; return [OHHTTPStubsResponse responseWithFileAtPath:fixture statusCode:200 headers:headers]; }]; ...
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    { "created_at": "2014-04-21 23:08:00 +0200", "email": "kyle@cocoapods.org", "name": "Kyle Fuller",

    "sessions": [ { "created_at": "2014-05-04 15:20:19 +0200", "valid_until": "2014-09-09 15:20:19 +0200", "verified": false }, { "created_at": "2014-05-04 15:20:20 +0200", "valid_until": "2014-09-09 15:20:20 +0200", "verified": true } ] } { "name": "QueryKit", "version": "0.8.3", "authors": { "Kyle Fuller": "inbox@kylefuller.co.uk" }, "social_media_url": "http://twitter.com/kylefuller", "source": { "git": "https://github.com/QueryKit/QueryKit.git", "tag": "0.8.3" }, "source_files": [ "QueryKit/*.{h}", "QueryKit/ObjectiveC/*.{h,m}" ], "requires_arc": true } ...
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    let URL = NSBundle.mainBundle().URIForResource("palaver", withExtension:"apib.json") requestReplayManager.addRecordings(fromBlueprintURL:URL, error:nil)

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    GET /sessions

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    None
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    EMBRACE CHANGE

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    None
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    WE MADE A MISTAKE.

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    WE WANT TO CHANGE... ENDPOINT URI.

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    NEGOTIATE AT RUN-TIME

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    WE WANT TO CHANGE... PAGINATION LOGIC.

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    FOLLOWING LINKS

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    TRANSITION BETWEEN STATES

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    "Paging is achieved with the published_before parameter."

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    published_before

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    [ { "published_date": "2013-04-30T16:05:45+00:00", ... } ]

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    GET /articles?published_before=2013-04-30T16:05:45+00:00

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    SERVER LOGIC

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    Next Page = <some URI>

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    Prevent BREAKING CHANGES

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    BUILDING BETTER CLIENTS from THE API

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    FLEXIBILITY

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    CASCADED REQUESTS

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    GET /categories GET /authors GET /articles

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    BANDWIDTH

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    LARGE DATA

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    $ curl -I http://api.something.com/articles HTTP/1.1 200 OK Content-Type: application/json Content-Length:

    12524998
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    BREAK IT UP

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    PAGINATION

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    /list VS /list/detail

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    USE Last-Modified

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    USE Cache-Control

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    USE STANDARDS

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    LET’S BUILD BETTER APIS TOGETHER

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    KYLE FULLER