elm-spa

elm-spa

installation

npm install -g elm-spa

available commands

• elm-spa init – create a new project
• elm-spa add – add a new page
• elm-spa build – generate routes and pages

elm-spa init

elm-spa init <directory>

  Create a new elm-spa app in the <directory>
  folder specified.

  examples:
  elm-spa init .
  elm-spa init my-app

elm-spa add

elm-spa add <static|sandbox|element|full> <name>

  Create a new page of type <static|sandbox|element|full>
  with the module name <name>.

  examples:
  elm-spa add static Top
  elm-spa add sandbox Posts.Top
  elm-spa add element Posts.Id_Int
  elm-spa add full SignIn

elm-spa build

elm-spa build [dir]

  Create "Generated.Route" and "Generated.Pages" modules for
  this project, based on the file names in "src/Pages"

  Here are more details on how that works:
  https://www.npmjs.com/package/elm-spa#naming-conventions

  examples:
  elm-spa build
  elm-spa build ../some/other-folder
  elm-spa build ./help

naming conventions

the elm-spa build command is pretty useful, because it automatically generates Routes.elm and Pages.elm code for you, based on the naming convention in src/Pages/*.elm

Here's an example project structure:

src/
└─ Pages/
   ├─ Top.elm
   ├─ About.elm
   ├─ Posts/
   |   ├─ Top.elm
   |   └─ Post_Int.elm
   └─ Authors/
       └─ Author_String/
           └─ Posts/
               └─ Post_Int.elm

When you run elm-spa build with these files in the src/Pages directory, elm-spa can automatically generate routes like these:

Page	Route	Example
Top.elm	/	-
About.elm	/about	-
Posts/Top.elm	/posts	-
Posts/Id_Int.elm	/posts/:id	/posts/123
Authors/Author_String/Posts/PostId_Int.elm	/authors/:author/posts/:postId	/authors/ryan/posts/123

top-level and dynamic routes

• Top.elm represents the top-level index in the folder.
• User_Int.elm defines a dynamic parameter named user that should be an Int.
• User_Int can also be a folder name, supporting nested dynamic routes.

accessing url parameters

These dynamic parameters are available as Params for the given page.

Here are some specific examples from the routes above:

module Pages.About exposing (..)

type alias Params =
    ()

module Pages.Posts.Id_Int exposing (..)

type alias Params =
    { post : Int
    }

module Pages.Authors.Author_String.Posts.PostId_Int exposing (..)

type alias Flags =
    { author : String
    , postId : Int
    }

These Params are automatically passed into the init function, along with other information like the query parameters and complete raw Url value.