Add complex flow sample program written in Go

Go/Complex Flow Examples/ocr-with-extract-text/go.mod

@@ -0,0 +1,3 @@
+module github.com/datalogics/pdf-rest-api-samples/go-ocr-extract
+
+go 1.24.2

Go/Complex Flow Examples/ocr-with-extract-text/ocr-with-extract-text.go

@@ -0,0 +1,124 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"os"
+)
+
+// In this sample, we will show how to convert a scanned document into a PDF with
+// searchable and extractable text using Optical Character Recognition (OCR), and then
+// extract that text from the newly created document.
+//
+// First, we will upload a scanned PDF to the /pdf-with-ocr-text route and capture the
+// output ID. Then, we will send the output ID to the /extracted-text route, which will
+// return the newly added text.
+
+func main() {
+	baseUrl := "https://api.pdfrest.com/"
+
+	// Replace the values below with your input file's location and name
+	inputFilePath := "/path/to/input.pdf"
+	inputFileName := "input.pdf"
+
+	// Replace with your API key
+	apiKey := "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
+
+	// Begin request to /pdf-with-ocr-text
+	// Create a buffer and a multipart writer
+	var ocrReqBody bytes.Buffer
+	ocrReqWriter := multipart.NewWriter(&ocrReqBody)
+
+	// Open the input file
+	fileField := "file"
+	file, err := os.Open(inputFilePath)
+	if err != nil {
+		panic(err)
+	}
+	defer file.Close()
+
+	filePart, err := ocrReqWriter.CreateFormFile(fileField, inputFileName)
+	if err != nil {
+		panic(err)
+	}
+	_, err = io.Copy(filePart, file)
+	if err != nil {
+		panic(err)
+	}
+
+	err = ocrReqWriter.Close()
+	if err != nil {
+		panic(err)
+	}
+
+	// Create the HTTP request
+	ocrReq, err := http.NewRequest("POST", baseUrl+"pdf-with-ocr-text", &ocrReqBody)
+	if err != nil {
+		panic(err)
+	}
+
+	// Set the headers
+	ocrReq.Header.Set("Content-Type", ocrReqWriter.FormDataContentType())
+	ocrReq.Header.Set("Api-Key", apiKey)
+
+	// Send the request
+	client := &http.Client{}
+	ocrResp, err := client.Do(ocrReq)
+	if err != nil {
+		panic(err)
+	}
+	defer ocrResp.Body.Close()
+
+	var ocrRespData map[string]interface{}
+	err = json.NewDecoder(ocrResp.Body).Decode(&ocrRespData)
+	if err != nil {
+		panic(err)
+	}
+	errorMessage, hasErrorMessage := ocrRespData["error"]
+	if hasErrorMessage {
+		fmt.Println("ERR:", errorMessage)
+	} else {
+		// Begin request to /extracted-text
+		var extractReqBody bytes.Buffer
+		extractReqWriter := multipart.NewWriter(&extractReqBody)
+
+		// Add the "id" form field
+		err = extractReqWriter.WriteField("id", ocrRespData["outputId"].(string))
+		if err != nil {
+			panic(err)
+		}
+		err = extractReqWriter.Close()
+		if err != nil {
+			panic(err)
+		}
+		extractReq, err := http.NewRequest("POST", baseUrl+"extracted-text", &extractReqBody)
+		if err != nil {
+			panic(err)
+		}
+
+		extractReq.Header.Set("Content-Type", extractReqWriter.FormDataContentType())
+		extractReq.Header.Set("Api-Key", apiKey)
+
+		extractResp, err := client.Do(extractReq)
+		if err != nil {
+			panic(err)
+		}
+		defer extractResp.Body.Close()
+
+		var extractRespData map[string]interface{}
+		err = json.NewDecoder(extractResp.Body).Decode(&extractRespData)
+		if err != nil {
+			panic(err)
+		}
+		errorMessage, hasErrorMessage := extractRespData["error"]
+		if hasErrorMessage {
+			fmt.Println("ERR:", errorMessage)
+		} else {
+			fmt.Println(extractRespData["fullText"])
+		}
+	}
+}