generate route to href function

.gitignore

@@ -1,4 +1,5 @@
 .DS_Store
+.elm-spa
 elm-stuff
 node_modules
 dist

src/cli/src/cli/build.ts

@@ -9,6 +9,7 @@ import MsgTemplate from '../templates/msg'
 import ParamsTemplate from '../templates/params'
 import * as Process from '../process'
 import { bold, underline, colors, reset, check, dim } from "../terminal"
+import { isStaticPage } from "../templates/utils"
 
 export const build = (env : Environment) => () =>
   createMissingDefaultFiles()
@@ -58,7 +59,7 @@ const createMissingDefaultFiles = async () => {
 const scanForStaticPages = async (entries: PageEntry[]) : Promise<string[][]> => {
   const contents = await Promise.all(entries.map(e => File.read(e.filepath)))
   return contents
-    .map((content, i) => content.includes('exposing (page)') ? i : undefined)
+    .map((content, i) => isStaticPage(content) ? i : undefined)
     .filter(a => typeof a === 'number')
     .map((i : any) => entries[i].segments)
 }

src/cli/src/templates/routes.ts

@@ -1,10 +1,10 @@
-import { routeTypeDefinition, indent, routeParserList, paramsImports, Options } from "./utils"
+import { routeTypeDefinition, indent, routeParserList, paramsImports, Options, routeToHref } from "./utils"
 
 export default (pages : string[][], _options : Options) : string => `
 module Gen.Route exposing
     ( Route(..)
     , fromUrl
-    -- , toUrl
+    , toHref
     )
 
 ${paramsImports(pages)}
@@ -25,8 +25,13 @@ routes =
 ${indent(routeParserList(pages), 1)}
 
 
--- toUrl : Route -> Url
+toHref : Route -> String
--- toUrl route =
+toHref route =
---     Debug.todo "Gen.Route.toUrl"
+    let
+        joinAsHref : List String -> String
+        joinAsHref segments =
+            "/" ++ String.join "/" segments
+    in
+${indent(routeToHref(pages), 1)}
 
 `.trimLeft()

src/cli/src/templates/utils.ts

@@ -12,13 +12,18 @@ const isHomepage = (path: string[]) =>
 const isNotFoundPage = (path: string[]) =>
   path.join('') === config.reserved.notFound
 
-// [ 'Users', 'Name_', 'Settings' ] => [ 'Name_' ]
+// [ 'Users', 'Name_', 'Settings' ] => [ 'Name' ]
 const dynamicRouteSegments = (path : string[]) : string[] =>
   isHomepage(path) || isNotFoundPage(path)
     ? []
-    : path.filter(segment => segment.endsWith('_'))
+    : path.filter(isDynamicSegment)
         .map(segment => segment.substr(0, segment.length - 1))
 
+const isDynamicSegment = (segment : string) : boolean =>
+  segment !== config.reserved.homepage
+  && segment !== config.reserved.notFound
+  && segment.endsWith('_')
+
 // "AboutUs" => "aboutUs"
 const fromPascalToCamelCase = (str : string) : string =>
   str[0].toLowerCase() + str.substring(1)
@@ -127,6 +132,29 @@ export const routeTypeDefinition = (paths: string[][]) : string =>
 export const routeParserList = (paths: string[][]) : string =>
   multilineList(paths.map(routeParserMap))
 
+export const routeToHref = (paths: string[][]) : string =>
+  caseExpression(paths, {
+    variable: 'route',
+    condition: (path) => 
+      (dynamicRouteSegments(path).length === 0)
+        ? routeVariant(path) 
+        : `${routeVariant(path)} params`,
+    result: (path) => `joinAsHref ${routeToHrefSegments(path)}`
+  })
+
+export const routeToHrefSegments = (path: string[]) : string => {
+  const segments = path.filter(p => p !== config.reserved.homepage)
+  const hrefFragments =
+    segments.map(segment => 
+      isDynamicSegment(segment)
+        ? `params.${fromPascalToCamelCase(segment.substring(0, segment.length - 1))}`
+        : `"${fromPascalToSlugCase(segment)}"`
+    )
+  return hrefFragments.length === 0
+    ? `[]`
+    : `[ ${hrefFragments.join(', ')} ]`
+}
+
 export const paramsImports = (paths: string[][]) : string =>
   paths.map(path => `import Gen.Params.${path.join('.')}`).join('\n')
 
@@ -193,7 +221,6 @@ const msgVariant = (path: string[]) : string =>
 const msg = (path: string[]) : string =>
   `Pages.${path.join('.')}.Msg`
 
-
 export const pagesInitBody = (paths: string[][]) : string =>
   indent(caseExpression(paths, {
     variable: 'route',
@@ -241,3 +268,13 @@ const pageModelArguments = (path: string[], options : Options) : string =>
   options.isStatic(path)
     ? `params ()`
     : `params model`
+
+// Used in place of sophisticated AST parsing
+const exposes = (keyword: string) => (elmSourceCode: string): boolean =>
+  new RegExp(`module\\s(\\S)+\\sexposing(\\s)+\\([^\\)]*${keyword}[^\\)]*\\)`, 'm').test(elmSourceCode)
+
+export const exposesModel = exposes('Model')
+export const exposesMsg = exposes('Msg')
+
+export const isStaticPage = (sourceCode : string) : boolean =>
+  !exposesModel(sourceCode) || !exposesMsg(sourceCode)

src/cli/tests/templates/utils.spec.ts

@@ -143,4 +143,59 @@ type Route
 ]
     `.trim())
   })
+
+  test.each([
+    [ [ config.reserved.homepage ], `[]` ],
+    [ [ "AboutUs" ], `[ "about-us" ]` ],
+    [ [ "AboutUs", "Offices" ], `[ "about-us", "offices" ]` ],
+    [ [ "Posts" ], `[ "posts" ]` ],
+    [ [ "Posts", "Id_" ], `[ "posts", params.id ]` ],
+    [ [ "Users", "Name_", "Settings" ], `[ "users", params.name, "settings" ]` ],
+    [ [ "Users", "Name_", "Posts", "Id_" ], `[ "users", params.name, "posts", params.id ]` ],
+  ])(".routeVariant(%p)", (input, output) => {
+    expect(Utils.routeToHrefSegments(input)).toBe(output)
+  })
 })
+
+describe.each([['Model'], ['Msg']])
+  ('Utils.exposes%s', (name: string) => {
+    const fn = (Utils as any)[`exposes${name}`] as (val: string) => boolean
+
+    test('fails for exposing all', () =>
+      expect(fn(`module Layout exposing (..)`)).toBe(false)
+    )
+
+    test(`fails if missing keyword`, () => {
+      expect(fn(`module Layout exposing (OtherImport)`)).toBe(false)
+      expect(fn(`module Layout exposing
+                    ( OtherImport
+                    )
+      `)).toBe(false)
+    })
+
+    test(`works with single-line exposing "${name}"`, () => {
+      expect(fn(`module Layout exposing (${name})`)).toBe(true)
+      expect(fn(`module Layout exposing (OtherImport, ${name})`)).toBe(true)
+      expect(fn(`module Layout exposing (${name}, OtherImport)`)).toBe(true)
+    })
+
+    test(`works with multi-line exposing "${name}"`, () => {
+      expect(fn(`
+        module Layout exposing
+            ( ${name}
+            )
+      `)).toBe(true)
+      expect(fn(`
+        module Layout exposing
+            ( OtherImport
+            , ${name}
+            )
+      `)).toBe(true)
+      expect(fn(`
+        module Layout exposing
+            ( ${name}
+            , OtherImport
+            )
+      `)).toBe(true)
+    })
+  })