added example for form fields with text colors

Author: kellemNegasi

forms/filled_form_rich.pdf

@@ -0,0 +1,124 @@
+/*
+* Fill PDF form via json data where field names and values along side text colors for each field are provided.
+*
+* Run as: go run form-fill-custom-text-color.go.
+ */
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/unidoc/unipdf/v3/annotator"
+	"github.com/unidoc/unipdf/v3/common/license"
+	"github.com/unidoc/unipdf/v3/creator"
+	"github.com/unidoc/unipdf/v3/fjson"
+	"github.com/unidoc/unipdf/v3/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)
+	}
+}
+
+// FieldData represents the field data structure.
+type FieldData struct {
+	Name      string `json:"name"`
+	TextColor string `json:"text_color"`
+}
+
+func main() {
+	inputPath := "sample_form.pdf"
+	jsonDataPath := "sample_form_rich.json"
+	outputPath := "filled_form_rich.pdf"
+
+	fdata, err := fjson.LoadFromJSONFile(jsonDataPath)
+	if err != nil {
+		fmt.Printf("failed to load json file. Error : %v\n", err)
+		os.Exit(1)
+	}
+
+	f, err := os.Open(inputPath)
+	if err != nil {
+		fmt.Printf("failed to open input file. Error : %v\n", err)
+		os.Exit(1)
+	}
+	defer f.Close()
+
+	pdfReader, err := model.NewPdfReader(f)
+	if err != nil {
+		fmt.Printf("failed to read pdf file. Error : %v\n", err)
+		os.Exit(1)
+	}
+
+	fieldColor, err := loadFieldColors(jsonDataPath)
+	if err != nil {
+		fmt.Printf("failed to load field colors. Error : %v\n", err)
+		os.Exit(1)
+	}
+
+	fieldAppearance := annotator.FieldAppearance{OnlyIfMissing: true, RegenerateTextFields: true}
+
+	fieldAppearance.SetStyle(annotator.AppearanceStyle{
+		AutoFontSizeFraction: 0.70,
+		FillColor:            model.NewPdfColorDeviceRGB(1, 1, 1),
+		BorderColor:          model.NewPdfColorDeviceRGB(0, 0, 0),
+		BorderSize:           2.0,
+		AllowMK:              false,
+		TextColor:            model.NewPdfColorDeviceRGB(0.5, 0.8, 0.8), // Default text color.
+		FieldColors:          fieldColor,                                // This specifies the text color for each field.
+	})
+
+	pdfReader.AcroForm.FillWithAppearance(fdata, fieldAppearance)
+	pdfWriter, err := pdfReader.ToWriter(nil)
+	if err != nil {
+		fmt.Printf("failed to convert reader to writer pdf file. Error : %v\n", err)
+		os.Exit(1)
+	}
+
+	// Write to file.
+	err = pdfWriter.WriteToFile(outputPath)
+	if err != nil {
+		fmt.Printf("failed to write to output file. Error : %v\n", err)
+		os.Exit(1)
+	}
+	fmt.Printf("Success, output written to %s\n", outputPath)
+}
+
+func loadFieldColors(jsonPath string) (map[string]model.PdfColor, error) {
+	file, err := os.Open(jsonPath)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	byteValue, err := ioutil.ReadAll(file)
+	if err != nil {
+		return nil, err
+	}
+
+	var fields []FieldData
+	err = json.Unmarshal(byteValue, &fields)
+	if err != nil {
+		return nil, err
+	}
+
+	fieldColors := make(map[string]model.PdfColor)
+	for _, field := range fields {
+		if field.TextColor == "" {
+			continue
+		}
+		tc := creator.ColorRGBFromHex(field.TextColor)
+		r, g, b := tc.ToRGB()
+		tcRGB := model.NewPdfColorDeviceRGB(r, g, b)
+		fieldColors[field.Name] = tcRGB
+	}
+
+	return fieldColors, nil
+}

forms/form-fill-custom-text-color.go

@@ -0,0 +1,71 @@
+[
+    {
+        "name": "formID",
+        "value": "202286033286049"
+    },
+    {
+        "name": "pdf_submission_new",
+        "value": "1",
+        "text_color": "#40E0D0"
+    },
+    {
+        "name": "simple_spc",
+        "value": "202286033286049-202286033286049",
+        "text_color": "#6495ED"
+    },
+    {
+        "name": "adobeWarning",
+        "value": "In order to submit this form, you should open it with Adobe Acrobat Reader.",
+        "text_color": "#008000"
+    },
+    {
+        "name": "name3[first]",
+        "value": "John",
+        "text_color": "#0000FF",
+        "fill_color": "#FFD700",
+        "border_color": "#CD5C5C"
+    },
+    {
+        "name": "name3[last]",
+        "value": "Doe",
+        "text_color": "#7dcea0"
+    },
+    {
+        "name": "email4",
+        "value": "alpha@omega.com",
+        "text_color": "#CD5C5C"
+    },
+    {
+        "name": "address5[addr_line1]",
+        "value": "sample address line 1",
+        "text_color": "#008000"
+    },
+    {
+        "name": "address5[addr_line2]",
+        "value": "sample address line 2",
+        "text_color": "#40E0D0"
+    },
+    {
+        "name": "address5[city]",
+        "value": "sample address",
+        "text_color": "#00FF00"
+    },
+    {
+        "name": "address5[state]",
+        "value": "sample state",
+        "text_color": "#2596be"
+    },
+    {
+        "name": "address5[postal]",
+        "value": "3538148",
+        "text_color": "#063970"
+    },
+    {
+        "name": "fakeSubmitButton",
+        "value": "Submit"
+    },
+    {
+        "name": "submitButton",
+        "value": ""
+    }
+]