Feat: Add support for 'build: true' tag in frontmatter

This feature allows triggering the execution of the `build_action` command specified in
the `.ini` file when adding `build: true` to the frontmatter of the modified file. Upon
detecting this tag, the specified command will be executed automatically, facilitating
the automation of build processes in response to specific file modifications

README.md

@@ -15,6 +15,7 @@ Configuration runs in `~/.config/obs2hugo/obs2hugo.ini` or `~/.config/obs2hugo.i
 ```ini
 watcher_dirs = /Users/johndoe/vaults/obsidian/microposts-hugo:/Users/johndoe/vaults/obsidian/posts-hugo
 hugo_dirs = /Users/johndoe/code/hugo/src/content/posts:/Users/johndoe/code/hugo/src/content/microposts
+build_action = hugo build
 ```
 
 Note: The `watcher_dirs` and `hugo_dirs` variables must have the same number of elements, taking into account that `:` acts as a separator. They are correlated so the first element in `watcher_dirs` corresponds to the first element in `hugo_dirs`, the second element in `watcher_dirs` corresponds to the second element in `hugo_dirs`, and so forth.
@@ -29,6 +30,8 @@ Note: The `watcher_dirs` and `hugo_dirs` variables must have the same number of
 $ go run main.go
 ```
 
+If you add `build: true` in the frontmatter of the file you are modifying, it will force the execution of the `build_action` command specified in the `.ini` file.
+
 ## Requirements
 
 - Go installed on your system.

main.go

@@ -8,6 +8,7 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -32,6 +33,9 @@ func main() {
 			log.Fatalln(err)
 		}
 	}
+	// Hugo build action
+	buildAction := config.Section("").Key("build_action").String()
+
 	// Watcher directories
 	watcherDirs := config.Section("").Key("watcher_dirs").String()
 
@@ -93,6 +97,28 @@ func main() {
 					continue
 				}
 				processModifiedFile(event.Name, triggerDir, newDestDir)
+				// Check if the file contains the "build: true" tag in the frontmatter
+				hasBuildTag, err := hasBuildTag(event.Name)
+				if err != nil {
+					fmt.Println("Error checking build tag in frontmatter:", err)
+					continue
+				}
+
+				// If the file contains the "build: true" tag, execute the build action specified in the .ini file
+				if hasBuildTag && buildAction != "" {
+					// Remove the "build: true" tag from the frontmatter
+					err = removeBuildTag(event.Name)
+					if err != nil {
+						fmt.Println("Error removing build tag from frontmatter:", err)
+						return
+					}
+					// Execute build action
+					err := executeBuildAction(buildAction)
+					if err != nil {
+						fmt.Println("Error executing build action:", err)
+						continue
+					}
+				}
 			case event.Op&fsnotify.Remove == fsnotify.Remove:
 				fmt.Println("File deleted:", event.Name)
 				// TBD
@@ -217,6 +243,65 @@ func addFrontmatter(filePath, title string) error {
 	return nil
 }
 
+// Function to check if the file contains the "build: true" tag in the frontmatter
+func hasBuildTag(filePath string) (bool, error) {
+	// Open the file
+	file, err := os.Open(filePath)
+	if err != nil {
+		return false, err
+	}
+	defer file.Close()
+
+	// Read the file line by line
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		// Check for the start of the frontmatter
+		if line == "---" {
+			var frontmatter []string
+
+			// Read the frontmatter
+			for scanner.Scan() {
+				line := scanner.Text()
+				if line == "---" {
+					break
+				}
+				frontmatter = append(frontmatter, line)
+			}
+
+			// Check if the frontmatter contains the "build: true" tag
+			for _, tag := range frontmatter {
+				if strings.Contains(tag, "build: true") {
+					return true, nil
+				}
+			}
+			break // We're done checking frontmatter, so break out of the loop
+		}
+	}
+
+	return false, nil
+}
+
+// Function to execute the build action specified in the .ini file
+func executeBuildAction(action string) error {
+	// Split the action into command and arguments
+	parts := strings.Fields(action)
+	cmd := parts[0]
+	args := parts[1:]
+
+	// Execute the command
+	out, err := exec.Command(cmd, args...).Output()
+	if err != nil {
+		return err
+	}
+
+	// Print the command output
+	fmt.Println(string(out))
+
+	return nil
+}
+
 func copyFile(src, dst string) error {
 	sourceFile, err := os.Open(src)
 	if err != nil {
@@ -237,6 +322,41 @@ func copyFile(src, dst string) error {
 	return nil
 }
 
+func removeBuildTag(filePath string) error {
+	// Read file content
+	content, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		return err
+	}
+
+	contentStr := string(content)
+
+	// Find frontmatter
+	start := strings.Index(contentStr, "---")
+	end := strings.Index(contentStr[start+3:], "---")
+
+	// Verify if frontmatter exists
+	if start != -1 && end != -1 {
+		frontmatter := contentStr[start : start+3+end+3]
+
+		// Look for "build: true" in the frontmatter
+		buildTagIndex := strings.Index(frontmatter, "build: true")
+		if buildTagIndex != -1 {
+			// Delete "build: true" from frontmatter
+			frontmatter = strings.ReplaceAll(frontmatter, "build: true\n", "")
+
+			contentStr = strings.Replace(contentStr, string(content[start:start+3+end+3]), frontmatter, 1)
+
+			err := ioutil.WriteFile(filePath, []byte(contentStr), 0644)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
 func moveImagesToGallery(filePath, destDir, directory string) error {
 	// Routes
 	destFilePath := filepath.Join(destDir, "index.md")

obs2hugo.ini.sample

@@ -4,3 +4,4 @@
 
 watcher_dirs = /Users/johndoe/vaults/obsidian/microposts-hugo:/Users/johndoe/vaults/obsidian/posts-hugo
 hugo_dirs = /Users/johndoe/code/hugo/src/content/posts:/Users/johndoe/code/hugo/src/content/microposts
+build_action = hugo build