tag table example

Author: 3ace

accessibility/pdf_tag_table.go

@@ -0,0 +1,96 @@
+// This example demonstrates how to create a tagged PDF with a table
+// using the UniPDF library. The table will be properly tagged in the document
+// structure tree for accessibility compliance.
+//
+// The program creates a PDF document containing:
+// - A table with three columns and multiple rows
+// - Proper tagging structure for accessibility compliance
+// - Custom cell alignment and borders
+// - Structure tree root with K dictionaries for the table and its cells
+//
+// This is useful for creating accessible PDF documents that can be properly
+// interpreted by screen readers and other assistive technologies.
+
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/unidoc/unipdf/v4/common/license"
+	"github.com/unidoc/unipdf/v4/core"
+	"github.com/unidoc/unipdf/v4/creator"
+	"github.com/unidoc/unipdf/v4/model"
+)
+
+func init() {
+	// Make sure to load your metered License API key prior to using the library.
+	// If you need a key, you can sign up and create a free one at https://cloud.unidoc.io
+	err := license.SetMeteredKey(os.Getenv(`UNIDOC_LICENSE_API_KEY`))
+	if err != nil {
+		panic(err)
+	}
+}
+
+func main() {
+	c := creator.New()
+	c.SetPageMargins(50, 50, 50, 50)
+
+	structTreeRoot := model.NewStructTreeRoot()
+
+	// Construct base K dictionary.
+	docK := model.NewKDictionary()
+	docK.S = core.MakeName(string(model.StructureTypeDocument))
+	docK.ID = core.MakeString(docK.GenerateRandomID())
+
+	// Add K dictionary to the struct tree root.
+	structTreeRoot.AddKDict(docK)
+
+	drawTable(c, docK)
+
+	// Set the struct tree root.
+	c.SetStructTreeRoot(structTreeRoot)
+
+	err := c.WriteToFile("pdf_tag_table.pdf")
+	if err != nil {
+		fmt.Printf("Error writing to file: %v\n", err)
+		return
+	}
+}
+
+func drawTable(c *creator.Creator, rootKObj *model.KDict) error {
+	// Create table.
+	table := c.NewTable(3)
+	table.SetMargins(0, 0, 10, 0)
+
+	drawCell := func(text string, align creator.CellHorizontalAlignment) {
+		p := c.NewStyledParagraph()
+		p.SetText(text)
+
+		cell := table.NewCell()
+		cell.SetBorder(creator.CellBorderSideAll, creator.CellBorderStyleSingle, 1)
+		cell.SetHorizontalAlignment(align)
+		cell.SetContent(p)
+	}
+
+	// Draw table header.
+	drawCell("Align left", creator.CellHorizontalAlignmentLeft)
+	drawCell("Align center", creator.CellHorizontalAlignmentCenter)
+	drawCell("Align right", creator.CellHorizontalAlignmentRight)
+
+	// Draw table content.
+	for i := 0; i < 5; i++ {
+		num := i + 1
+
+		drawCell(fmt.Sprintf("Product #%d", num), creator.CellHorizontalAlignmentLeft)
+		drawCell(fmt.Sprintf("Description #%d", num), creator.CellHorizontalAlignmentCenter)
+		drawCell(fmt.Sprintf("$%d", num*10), creator.CellHorizontalAlignmentRight)
+	}
+
+	// Tag the table with the root K dictionary.
+	// This associates the table with the document structure tree.
+	// The table will be a child of the document structure tree.
+	table.AddTag(rootKObj)
+
+	return c.Draw(table)
+}