move litgo into own directory & refactor

This moves litgo into its own directory in order to prepare for having
multiple doc plugins.  It also refactors out the `{{#command}}` search
logic so that it can be used across plugins.

Author: DirectXMan12

docs/book/litgo.sh

@@ -4,7 +4,7 @@ set -ex
 
 (
     pushd ./utils
-    go build -o ../../../bin/literate-go ./literate.go
+    go build -o ../../../bin/literate-go ./litgo
     popd
 ) &>/dev/null
 

docs/book/utils/literate.go docs/book/utils/litgo/literate.go

@@ -1,3 +1,19 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 package main
 
 import (
@@ -23,48 +39,16 @@ import (
 type Literate struct {}
 func (_ Literate) SupportsOutput(_ string) bool { return true }
 func (_ Literate) Process(input *plugin.Input) error {
-	return plugin.EachItemInBook(&input.Book, func(chapter *plugin.BookChapter) error {
-		if chapter.Content == "" {
-			return nil
-		}
-
-		// figure out all the trigger expressins
-		partsRaw := strings.Split(chapter.Content, "{{#literatego ")
-		// the first section won't start with `{{#literatego ` as per how split works
-		if len(partsRaw) < 2 {
-			return nil
-		}
-
-		var res []string
-		res = append(res, partsRaw[0])
-		for _, part := range partsRaw[1:] {
-			endDelim := strings.Index(part, "}}")
-			if endDelim < 0 {
-				return fmt.Errorf("missing end delimiter in chapter %q", chapter.Name)
-			}
-			// we need to join the path with the context root and the book's
-			// source directory, since we assume paths are relative to the
-			// given chapter file, like `{{#include}}`
-			relPath := part[:endDelim]
-			path := filepath.Join(input.Context.Root, input.Context.Config.Book.Src, filepath.Dir(chapter.Path), relPath)
-
-			// TODO(directxman12): don't escape root?
-			contents, err := ioutil.ReadFile(path)
-			if err != nil {
-				return fmt.Errorf("unable to import %q: %v", path, err)
-			}
-
-			newContents, err := extractContents(contents, path)
-			if err != nil {
-				return fmt.Errorf("unable to process %q: %v", path, err)
-			}
+	return plugin.EachCommand(&input.Book, "literatego", func(chapter *plugin.BookChapter, relPath string) (string, error) {
+		path := filepath.Join(input.Context.Root, input.Context.Config.Book.Src, filepath.Dir(chapter.Path), relPath)
 
-			res = append(res, string(newContents))
-			res = append(res, part[endDelim+2:])
+		// TODO(directxman12): don't escape root?
+		contents, err := ioutil.ReadFile(path)
+		if err != nil {
+			return "", fmt.Errorf("unable to import %q: %v", path, err)
 		}
 
-		chapter.Content = strings.Join(res, "")
-		return nil
+		return extractContents(contents, path)
 	})
 }
 

docs/book/utils/plugin/input.go

@@ -1,3 +1,19 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 package plugin
 
 import (

docs/book/utils/plugin/plugin.go

@@ -1,3 +1,19 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 package plugin
 
 import (

docs/book/utils/plugin/utils.go

@@ -0,0 +1,59 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package plugin
+
+import (
+	"fmt"
+	"strings"
+)
+
+// EachCommand looks for mustache-like declarations of the form `{{#cmd args}}`
+// in each book chapter, and calls the callback for each one, substituting it
+// for the result.
+func EachCommand(book *Book, cmd string, callback func(chapter *BookChapter, args string) (string, error)) error {
+	cmdStart := fmt.Sprintf("{{#%s ", cmd)
+	return EachItemInBook(book, func(chapter *BookChapter) error {
+		if chapter.Content == "" {
+			return nil
+		}
+
+		// figure out all the trigger expressins
+		partsRaw := strings.Split(chapter.Content, cmdStart)
+		// the first section won't start with `{{#<cmd> ` as per how split works
+		if len(partsRaw) < 2 {
+			return nil
+		}
+
+		var res []string
+		res = append(res, partsRaw[0])
+		for _, part := range partsRaw[1:] {
+			endDelim := strings.Index(part, "}}")
+			if endDelim < 0 {
+				return fmt.Errorf("missing end delimiter in chapter %q", chapter.Name)
+			}
+			newContents, err := callback(chapter, part[:endDelim])
+			if err != nil {
+				return err
+			}
+			res = append(res, string(newContents))
+			res = append(res, part[endDelim+2:])
+		}
+
+		chapter.Content = strings.Join(res, "")
+		return nil
+	})
+}