API Documentation

Inline Documentation for RESTful web APIs
apiDoc introduction with a small example.
http://apidocjs.com

Transcript

1. APIDOC
   Inline Documentation for RESTful web APIs
   Introduction with a small example.
   http://apidocjs.com
   

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2. What does apiDoc ?
   apiDoc
   … creates a Documentation HTML-Page
   … use API-Descriptions from your source code
   For who ?
   apiDoc can be used with any programming language, that allow
   block documentation:
   /**
   * This is a comment.
   */
   

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3. Where i find apiDoc ?
   apiDoc is Open Source and distributed over NPM and github
   Visit: http://apidocjs.com
   Special functions
   apiDoc
   … support own created Templates
   … includes History
   … compare old and new API-Method Versions
   … allows frontend Developer to see what changed
   … support Inherit
   … reuse of Documentation parts
   … extendable
   … you can create your own Documentation Methods
   

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4. Ok, let us begin...
   apiDoc is a node module, so install Node.js first:
   http://nodejs.org
   Node.js includes „npm“, a package manager for node.
   Install apiDoc
   [sudo] npm install -g apidoc
   We install apiDoc global, so you can access it from everywhere.
   

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5. EXAMPLE PROJECT
   We use a simple static JavaScript example.
   We ignore routing, validation or database operations.
   This are only small parts of apiDocs functions, for all visit http://apidocjs.com
   There is also a complex example: http://apidocjs.com/#example-full
   

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6. Create a new directory „my_project“.
   Within that dir create a file „example.js“.
   example.js
   var currentUser = {
   name: 'Mary'
   };
   function getUser() {
   return { code: 200, data: currentUser };
   }
   function setName(name) {
   if(name.length === 0) {
   return { code: 404, message: 'NameEmptyError' };
   }
   currentUser.name = name;
   return { code: 204 };
   }
   

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7. A basic doc
   Above „function getUser“ we place a basic documentation block
   /**
   * @api {get} /user Request User information
   * @apiName GetUser
   * @apiGroup User
   */
   function getUser() {
   return { code: 200, data: currentUser };
   }
   This 3 parameters are required!
   @api describes the path of the Method that clients call.
   @apiName is a unique Name, you can name as you want, for simplicity i prefer
   „Type of Method“ + „Name of Method“ e.g. {get} and „/user“ => GetUser.
   @apiGroup is the name of the group to which this method belongs. The group will be
   used for Navigation.
   

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8. By default apiDoc search for all „.jjs“ files in current directory and sub directories.
   You can change the includeFilter, call „apidoc -h“ for details.
   apiDoc created a new HTML-Page in directory „doc“.
   From command line run within „my_project“ directory:
   apidoc
   

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9. Open „doc/index.html“ in your Browser
   We see the rudimentary Webpage, with Navigation left and Content right.
   We have a group „User“ and within that group an API-Method „GET /user“
   

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10. Describe the API-Answer
    Now we add success return parameters
    /**
    * @api {get} /user Request User information
    * @apiName GetUser
    * @apiGroup User
    *
    * @apiSuccess {String} name The users name.
    */
    function getUser() {
    return { code: 200, data: currentUser };
    }
    apidoc
    Run apiDoc again, it will overwrite the „doc“ Directory
    

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11. Now we have a little more Information and see what „GET /user“ returns on a
    successful reply „Success 200“.
    

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12. Add a Version and example Code
    We add a Version (Format “major.minor.patch”, see http://semver.org for details)
    and we add an example code, that shows what will be return in case of success
    /**
    * @api {get} /user Request User information
    * @apiName GetUser
    * @apiGroup User
    * @apiVersion 0.1.0
    *
    * @apiSuccess {String} name The users name.
    *
    * @apiSuccessExample Example data on success:
    * {
    * name: 'Paul'
    * }
    */
    function getUser() {
    return { code: 200, data: currentUser };
    }
    

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13. In the right dropdown box we see now the Version „0.1.0“ and under „Success 200“
    our integrated example.
    

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14. VERSIONING
    If you work in a Team and some Programmer work an the API backend and some on
    Frontend Client, it is important to know what changed in a new Release.
    Especially during developing an Application, many things can change.
    

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15. An API Method change
    Create a new file „_apidoc.js“.
    Put only the documentation Block from „getUser“ in that file:
    _apidoc.js
    /**
    * @api {get} /user Request User information
    * @apiName GetUser
    * @apiGroup User
    * @apiVersion 0.1.0
    *
    * @apiSuccess {String} name The users name.
    *
    * @apiSuccessExample Example data on success:
    * {
    * name: 'Paul'
    * }
    */
    „_apidoc.js“ will be our history file and contains old documentation blocks.
    

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16. Now we change the documentation block in „example.js“
    example.js
    /**
    * @api {get} /user Request User information
    * @apiName GetUser
    * @apiGroup User
    * @apiVersion 0.2.0
    *
    * @apiSuccess {String} name The users name.
    * @apiSuccess {Number} age Calculated age from Birthday
    *
    * @apiSuccessExample Example data on success:
    * {
    * name: 'Paul',
    * age: 27
    * }
    */
    function getUser() {
    return { code: 200, data: currentUser };
    }
    

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17. After call „apidoc“ and open „doc/index.html“ you see now Version „0.2.0“ with the
    Field „age“ and the changed example.
    

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18. And now the magic...
    

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19. Select from Dropdown „0.2.0“ the Version „0.1.0“.
    You see now a comparison from the 2 Versions. Green marked content indicates the
    Fields that are added to Version „0.2.0“.
    

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20. In the future, when you made more changes to an API-Method, simply copy and add
    the complete documentation block to the history file „_apidoc.js“.
    Leave the old blocks as they are.
    Then you have a Documentation where everybody can see any change of your API.
    

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21. PARAMS AND ERRORS
    We take now a quick look at how to add Parameters, that an API-Method need and
    how we return errors.
    

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22. We add now a documentation to our second function „setName“.
    example.js
    /**
    * @api {put} /user Change User
    * @apiName PutUser
    * @apiGroup User
    * @apiVersion 0.1.0
    *
    * @apiParam {String} name New name of the user
    *
    * @apiError NameEmptyError The name was empty. Minimum of 1 character is required.
    */
    function setName(name) {
    if(name.length === 0) {
    return { code: 404, message: 'NameEmptyError' };
    }
    currentUser.name = name;
    return { code: 204 };
    }
    

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23. You will see now the new „Change User“ entry in navigation and the content for the
    API-Method.
    

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24. Thank you and have a productive use !
    For more Information visit http://apidocjs.com
    Author: Peter Rottmann
    peter@apidocjs.com
    

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