83 lines
2.2 KiB
Go
83 lines
2.2 KiB
Go
package pdfrender
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import (
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"context"
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"encoding/base64"
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"fmt"
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"time"
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"github.com/chromedp/cdproto/page"
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"github.com/chromedp/chromedp"
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)
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// PDFRenderer handles HTML to PDF conversion using chromedp
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type PDFRenderer struct {
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// Configuration options can be added here later
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}
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// NewPDFRenderer creates a new PDF renderer
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func NewPDFRenderer() *PDFRenderer {
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return &PDFRenderer{}
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}
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// RenderHTMLToPDF converts HTML string to PDF bytes using chromedp
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func (r *PDFRenderer) RenderHTMLToPDF(html string) ([]byte, error) {
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// Create context with timeout
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ctx, cancel := chromedp.NewContext(context.Background())
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defer cancel()
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// Set timeout for PDF generation
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ctx, cancel = context.WithTimeout(ctx, 30*time.Second)
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defer cancel()
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var pdfBytes []byte
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// Configure PDF printing options for A4 landscape
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printParams := page.PrintToPDF().
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WithPaperWidth(11.69). // A4 landscape width in inches
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WithPaperHeight(8.27). // A4 landscape height in inches
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WithMarginTop(0). // No margins (template handles spacing)
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WithMarginBottom(0).
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WithMarginLeft(0).
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WithMarginRight(0).
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WithPrintBackground(true). // Include background colors/images
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WithPreferCSSPageSize(true) // Use CSS page size if specified
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// Execute chromedp tasks
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err := chromedp.Run(ctx,
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chromedp.Navigate("about:blank"),
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chromedp.ActionFunc(func(ctx context.Context) error {
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// Set HTML content
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frameTree, err := page.GetFrameTree().Do(ctx)
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if err != nil {
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return err
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}
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return page.SetDocumentContent(frameTree.Frame.ID, html).Do(ctx)
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}),
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chromedp.ActionFunc(func(ctx context.Context) error {
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// Wait a bit for rendering
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time.Sleep(500 * time.Millisecond)
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return nil
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}),
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chromedp.ActionFunc(func(ctx context.Context) error {
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// Print to PDF
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var err error
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pdfBytes, _, err = printParams.Do(ctx)
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return err
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}),
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)
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if err != nil {
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return nil, fmt.Errorf("chromedp failed to render PDF: %w", err)
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}
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return pdfBytes, nil
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}
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// ImageToBase64DataURI converts image bytes to a data URI for embedding in HTML
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func ImageToBase64DataURI(imageData []byte, mimeType string) string {
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encoded := base64.StdEncoding.EncodeToString(imageData)
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return fmt.Sprintf("data:%s;base64,%s", mimeType, encoded)
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}
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