add function convert html

converter/converter.go

@@ -17,14 +17,18 @@ import (
 
 // html to pdf converter structure for
 type Converter struct {
-	chromePath string
-	ctx        context.Context
-	cancel     context.CancelFunc
+	chromePath    string
+	allocCtx      context.Context
+	allocCancel   context.CancelFunc // Cancels the whole Chrome process manager
+	browserCtx    context.Context    // The specific browser instance
+	browserCancel context.CancelFunc // Closes the browser
+	progress      func(progress int)
 }
 
 // NewConverter starts a new converter instance with a chrome headless shell executable
 func NewConverter(chromePath string) (*Converter, error) {
 	var err error
+
 	c := &Converter{chromePath: chromePath}
 	chromePath, err = c.getChromePath()
 	if err != nil {
@@ -38,15 +42,33 @@ func NewConverter(chromePath string) (*Converter, error) {
 		chromedp.DisableGPU,
 	)
 
-	var allocCtx context.Context
-	allocCtx, c.cancel = chromedp.NewExecAllocator(context.Background(), opts...)
-	c.ctx, c.cancel = chromedp.NewContext(allocCtx)
+	opts = append(opts, platformOptions())
+
+	c.allocCtx, c.allocCancel = chromedp.NewExecAllocator(context.Background(), opts...)
+	c.browserCtx, c.browserCancel = chromedp.NewContext(c.allocCtx)
+
+	// 5. "Warm up" the browser to ensure the executable actually runs
+	// This catches "file not found" or permission errors immediately
+	err = chromedp.Run(c.browserCtx)
+	if err != nil {
+		c.Close() // Cleanup if start fails
+		return nil, fmt.Errorf("failed to start chrome: %w", err)
+	}
+
 	return c, nil
 }
 
+func (c *Converter) SetProgressCallback(cb func(progress int)) {
+	c.progress = cb
+}
+
 // Convert converts all given input files
 func (c *Converter) Convert(files ...models.File) error {
-	for _, f := range files {
+	for i, f := range files {
+		if c.progress != nil {
+			c.progress(i + 1)
+		}
+
 		if f.Input == "" || filepath.Ext(f.Input) != ".html" {
 			return fmt.Errorf("no .html input file path provided: %s", f.Input)
 		} else if f.Output == "" || filepath.Ext(f.Output) != ".pdf" {
@@ -69,11 +91,11 @@ func (c *Converter) Convert(files ...models.File) error {
 
 		htmlURL.WriteString(filepath.ToSlash(absPath))
 
-		c.ctx, c.cancel = context.WithTimeout(c.ctx, 60*time.Second)
-		defer c.cancel()
+		taskCtx, taskCancel := chromedp.NewContext(c.browserCtx)
+		timeoutCtx, timeoutCancel := context.WithTimeout(taskCtx, 60*time.Second)
 
 		var pdfData []byte
-		err = chromedp.Run(c.ctx,
+		err = chromedp.Run(timeoutCtx,
 			chromedp.Navigate(htmlURL.String()),
 			chromedp.WaitReady("body", chromedp.ByQuery),
 			chromedp.ActionFunc(func(ctx context.Context) error {
@@ -89,6 +111,9 @@ func (c *Converter) Convert(files ...models.File) error {
 				return nil
 			}),
 		)
+
+		timeoutCancel()
+		taskCancel()
 		if err != nil {
 			return err
 		}
@@ -101,6 +126,69 @@ func (c *Converter) Convert(files ...models.File) error {
 	return nil
 }
 
+// Convert converts all given input files
+func (c *Converter) ConvertHtml(html []byte, outputPath string) error {
+
+	if len(html) == 0 {
+		return fmt.Errorf("no .html input provided")
+	} else if outputPath == "" || filepath.Ext(outputPath) != ".pdf" {
+		return fmt.Errorf("no .pdf output file path provided: %s", outputPath)
+	}
+
+	taskCtx, taskCancel := chromedp.NewContext(c.browserCtx)
+	timeoutCtx, timeoutCancel := context.WithTimeout(taskCtx, 60*time.Second)
+
+	var pdfData []byte
+	err := chromedp.Run(timeoutCtx,
+		// Start with a blank page
+		chromedp.Navigate("about:blank"),
+		// Inject HTML directly
+		chromedp.ActionFunc(func(ctx context.Context) error {
+			frameTree, err := page.GetFrameTree().Do(ctx)
+			if err != nil {
+				return err
+			}
+
+			return page.SetDocumentContent(frameTree.Frame.ID, string(html)).Do(ctx)
+		}),
+		chromedp.WaitReady("body", chromedp.ByQuery),
+		chromedp.ActionFunc(func(ctx context.Context) error {
+			buf, _, err := page.PrintToPDF().
+				WithPrintBackground(true).
+				WithPaperWidth(8.27).
+				WithPaperHeight(11.69).
+				Do(ctx)
+			if err != nil {
+				return err
+			}
+			pdfData = buf
+			return nil
+		}),
+	)
+
+	timeoutCancel()
+	taskCancel()
+	if err != nil {
+		return err
+	}
+
+	// Save PDF to file
+	if err := os.WriteFile(outputPath, pdfData, 0644); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *Converter) Close() {
+	// Close browser first, then allocator
+	if c.browserCancel != nil {
+		c.browserCancel()
+	}
+	if c.allocCancel != nil {
+		c.allocCancel()
+	}
+}
+
 // getChromePath checks for system Chrome, else falls back to bundled headless shell
 func (c *Converter) getChromePath() (string, error) {
 

converter/hideOthers.go

@@ -0,0 +1,10 @@
+//go:build !windows
+
+package converter
+
+import "github.com/chromedp/chromedp"
+
+func platformOptions() chromedp.ExecAllocatorOption {
+	// Returns a no-op option for Mac/Linux
+	return chromedp.NoSandbox
+}

converter/hideWindows.go

@@ -0,0 +1,20 @@
+//go:build windows
+
+package converter
+
+import (
+	"os/exec"
+	"syscall"
+
+	"github.com/chromedp/chromedp"
+)
+
+func platformOptions() chromedp.ExecAllocatorOption {
+	return chromedp.ModifyCmdFunc(func(cmd *exec.Cmd) {
+		if cmd.SysProcAttr == nil {
+			cmd.SysProcAttr = &syscall.SysProcAttr{}
+		}
+		cmd.SysProcAttr.HideWindow = true
+		cmd.SysProcAttr.CreationFlags = 0x08000000 // CREATE_NO_WINDOW
+	})
+}

html2pdf.go

@@ -15,6 +15,8 @@ func Convert(chromePath, inputFile, outputFile string) error {
 	if err != nil {
 		return err
 	}
+	defer c.Close()
+
 	return c.Convert(input)
 }
 

html2pdf_test.go

@@ -1,6 +1,8 @@
 package html2pdf
 
 import (
+	"bytes"
+	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
@@ -41,13 +43,77 @@ func TestConvertFiles(t *testing.T) {
 		})
 	}
 
-	c, err := converter.NewConverter("./assets")
+	c, err := converter.NewConverter("assets/chrome-headless-shell/win64")
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer c.Close()
+
+	c.SetProgressCallback(func(progress int) {
+		fmt.Println(progress)
+	})
 
 	if err := c.Convert(input...); err != nil {
 		t.Fatal(err)
 	}
 	t.Log("test successfull")
 }
+
+func TestConvertHtml(t *testing.T) {
+	t.Log("start test ConvertHtml")
+
+	// Skip in short mode (useful for CI)
+	if testing.Short() {
+		t.Skip("skipping ConvertHtml integration test in short mode")
+	}
+
+	html := []byte(`
+<!DOCTYPE html>
+<html>
+<head>
+	<meta charset="utf-8">
+	<title>Test PDF</title>
+	<style>
+		body { font-family: Arial, sans-serif; }
+		h1 { color: #333; }
+	</style>
+</head>
+<body>
+	<h1>Hello PDF</h1>
+	<p>This is a test.</p>
+</body>
+</html>
+`)
+
+	tmpDir := t.TempDir()
+	outputPath := filepath.Join(tmpDir, "test.pdf")
+
+	c, err := converter.NewConverter("assets/chrome-headless-shell/win64")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	err = c.ConvertHtml(html, outputPath)
+	if err != nil {
+		t.Fatalf("ConvertHtml failed: %v", err)
+	}
+
+	// Assert PDF exists
+	data, err := os.ReadFile(outputPath)
+	if err != nil {
+		t.Fatalf("PDF not created: %v", err)
+	}
+
+	// Assert non-empty
+	if len(data) == 0 {
+		t.Fatal("PDF file is empty")
+	}
+
+	// Assert valid PDF header
+	if !bytes.HasPrefix(data, []byte("%PDF-")) {
+		t.Fatalf("output is not a valid PDF (missing %%PDF- header)")
+	}
+
+	t.Log("ConvertHtml test successful")
+}