add --interval and --on-change support

cmd/pipet/main.go

@@ -4,6 +4,10 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+	"time"
 
 	"github.com/urfave/cli/v2"
 
@@ -38,7 +42,7 @@ func main() {
 			},
 			&cli.IntFlag{
 				Name:  "interval",
-				Value: 3,
+				Value: 0,
 				Usage: "Maximum number of pages to scrape",
 			},
 			&cli.StringFlag{
@@ -64,7 +68,9 @@ func runPipet(c *cli.Context, specFile string) error {
 	jsonOutput := c.Bool("json")
 	separators := c.StringSlice("separator")
 	templateFile := c.String("template")
+	onChange := c.String("on-change")
 	maxPages := c.Int("max-pages")
+	interval := c.Int("interval")
 
 	pipet := &common.PipetApp{
 		MaxPages:  maxPages,
@@ -77,18 +83,41 @@ func runPipet(c *cli.Context, specFile string) error {
 		return fmt.Errorf("error parsing spec file: %w", err)
 	}
 
-	log.Println("Executing blocks")
-	err = app.ExecuteBlocks(pipet)
-	if err != nil {
-		return fmt.Errorf("error executing blocks: %w", err)
-	}
+	iterate := true
+	previousValue := ""
+
+	for iterate {
+		newValue := ""
+		log.Println("Executing blocks")
+		err = app.ExecuteBlocks(pipet)
+		if err != nil {
+			return fmt.Errorf("error executing blocks: %w", err)
+		}
 
-	log.Println("Generating output")
-	if jsonOutput {
-		return outputs.OutputJSON(pipet)
-	} else if templateFile != "" {
-		return outputs.OutputTemplate(pipet, templateFile)
-	} else {
-		return outputs.OutputText(pipet)
+		log.Println("Generating output")
+		if jsonOutput {
+			newValue = outputs.OutputJSON(pipet)
+		} else if templateFile != "" {
+			newValue = outputs.OutputTemplate(pipet, templateFile)
+		} else {
+			newValue = outputs.OutputText(pipet)
+		}
+
+		fmt.Print(newValue)
+
+		if interval > 0 {
+			if onChange != "" && previousValue != newValue {
+				command := strings.ReplaceAll(onChange, "{}", strconv.Quote(newValue))
+				log.Println("Executing on change command: " + command)
+				cmd := exec.Command("bash", "-c", command)
+				cmd.Output()
+				previousValue = newValue
+			}
+			pipet.Data = []interface{}{}
+			time.Sleep(time.Duration(interval) * time.Second)
+		} else {
+			iterate = false
+		}
 	}
+	return nil
 }

outputs/json.go

@@ -2,16 +2,12 @@ package outputs
 
 import (
 	"encoding/json"
-	"log"
 
 	"github.com/bjesus/pipet/common"
 )
 
-func OutputJSON(app *common.PipetApp) error {
-	jsonData, err := json.MarshalIndent(app.Data, "", "  ")
-	if err != nil {
-		return err
-	}
-	log.Println(string(jsonData))
-	return nil
+func OutputJSON(app *common.PipetApp) string {
+	jsonData, _ := json.MarshalIndent(app.Data, "", "  ")
+	return string(jsonData)
+
 }

outputs/template.go

@@ -1,17 +1,15 @@
 package outputs
 
 import (
+	"bytes"
 	"html/template"
-	"os"
 
 	"github.com/bjesus/pipet/common"
 )
 
-func OutputTemplate(app *common.PipetApp, templateFile string) error {
-	tmpl, err := template.ParseFiles(templateFile)
-	if err != nil {
-		return err
-	}
-
-	return tmpl.Execute(os.Stdout, app.Data)
+func OutputTemplate(app *common.PipetApp, templateFile string) string {
+	tmpl, _ := template.ParseFiles(templateFile)
+	var doc bytes.Buffer
+	tmpl.Execute(&doc, app.Data)
+	return doc.String()
 }

outputs/text.go

@@ -1,15 +1,14 @@
 package outputs
 
 import (
-	"log"
 	"strings"
 
 	"github.com/bjesus/pipet/common"
 	"github.com/bjesus/pipet/utils"
 )
 
-func OutputText(app *common.PipetApp) error {
+func OutputText(app *common.PipetApp) string {
 	flattenedData := utils.FlattenData(app.Data, 0)
-	log.Println(strings.Join(flattenedData, utils.GetSeparator(app, 0)))
-	return nil
+	return (strings.Join(flattenedData, utils.GetSeparator(app, 0)))
+
 }