Extract Invoice Information with SharePoint and PDF.co

Extract Invoices – Source Code Snippets

In order to get started with invoice extraction, we should analyze the code first. Take a look at the markup for Web Part visual control.

VisualWebPart1UserControl.ascx

<%@ Assembly Name="$SharePoint.Project.AssemblyFullName$" %>
<%@ Assembly Name="Microsoft.Web.CommandUI, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register Tagprefix="SharePoint" Namespace="Microsoft.SharePoint.WebControls" Assembly="Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register Tagprefix="Utilities" Namespace="Microsoft.SharePoint.Utilities" Assembly="Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce1119429c" %>
<%@ Register Tagprefix="asp" Namespace="System.Web.UI" Assembly="System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>
<%@ Import Namespace="Microsoft.SharePoint" %>
<%@ Register Tagprefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages" Assembly="Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="VisualWebPart1UserControl.ascx.cs" Inherits="ParseSimpleDocumentWebPart.VisualWebPart1.VisualWebPart1UserControl" %>

Choose source file<br />
<asp:FileUpload
    ID="FileUpload1"
    runat="server"
    Width="600px" />
<br /><br />

Document Parser template<br />
<asp:TextBox
    ID="TemplateTextBox"
    runat="server"
    Height="80px"
    TextMode="MultiLine"
    Width="600px" />
<br /><br />

<asp:Button
    ID="StartButton"
    runat="server"
    OnClick="StartButton_Click"
    Text="Extract Invoice Information"
    Width="610px" />
<br /><br />

Log<br />
<asp:TextBox
    ID="LogTextBox"
    runat="server"
    Height="80px"
    TextMode="MultiLine"
    Width="600px" />
<br /><br />

Result<br />
<asp:TextBox
    ID="ResultTextBox"
    runat="server"
    Height="500px"
    TextMode="MultiLine"
    Width="600px" />

This is code behind for Web Part User Control.

VisualWebPart1UserControl.ascx.cs

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Net;
using System.Text;
using System.Threading;
using System.Web.UI;

namespace ParseSimpleDocumentWebPart.VisualWebPart1
{
    public partial class VisualWebPart1UserControl : UserControl
    {
        // Configure your PDF.co API key in the project's Utils class.
        private readonly string API_KEY = Utils.API_KEY;

        // Run Document Parser asynchronously.
        private const bool Async = true;

        protected void Page_Load(object sender, EventArgs e)
        {
        }

        protected void StartButton_Click(object sender, EventArgs e)
        {
            LogTextBox.Text = "";
            ResultTextBox.Text = "";

            // Both a source file and a parser template are required.
            if (!FileUpload1.HasFile ||
                String.IsNullOrWhiteSpace(TemplateTextBox.Text))
            {
                LogTextBox.Text =
                    "Select a file and provide a Document Parser template.\n";
                return;
            }

            ServicePointManager.Expect100Continue = true;
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            try
            {
                using (WebClient webClient = new WebClient())
                {
                    webClient.Encoding = Encoding.UTF8;
                    webClient.Headers.Add("x-api-key", API_KEY);

                    // 1. Request a presigned URL for uploading the PDF.
                    // Encode only the filename, not the complete URL.
                    string query =
                        "https://api.pdf.co/v1/file/upload/get-presigned-url" +
                        "?contenttype=application/octet-stream&name=" +
                        Uri.EscapeDataString(FileUpload1.FileName);

                    string response = webClient.DownloadString(query);
                    JObject json = JObject.Parse(response);

                    if (json["error"].ToObject<bool>() == false)
                    {
                        string uploadUrl =
                            json["presignedUrl"].ToString();

                        string uploadedFileUrl =
                            json["url"].ToString();

                        // 2. Upload the PDF to the presigned storage URL.
                        // This request does not require the PDF.co API key.
                        using (WebClient uploadClient = new WebClient())
                        {
                            uploadClient.Headers[
                                HttpRequestHeader.ContentType
                            ] = "application/octet-stream";

                            uploadClient.UploadData(
                                uploadUrl,
                                "PUT",
                                FileUpload1.FileBytes
                            );
                        }

                        // 3. Submit the PDF and template to Document Parser.
                        string parserUrl =
                            "https://api.pdf.co/v1/pdf/documentparser";

                        Dictionary<string, object> requestBody =
                            new Dictionary<string, object>
                            {
                                { "template", TemplateTextBox.Text },
                                { "name", "result.json" },
                                { "url", uploadedFileUrl },
                                { "async", Async }
                            };

                        string jsonPayload =
                            JsonConvert.SerializeObject(requestBody);

                        webClient.Headers[
                            HttpRequestHeader.ContentType
                        ] = "application/json";

                        response = webClient.UploadString(
                            parserUrl,
                            "POST",
                            jsonPayload
                        );

                        json = JObject.Parse(response);

                        if (json["error"].ToObject<bool>() == false)
                        {
                            string jobId = json["jobId"].ToString();

                            string resultFileUrl = json["url"] == null
                                ? null
                                : json["url"].ToString();

                            // 4. Check the asynchronous job until it finishes.
                            while (true)
                            {
                                JObject job = CheckJobStatus(jobId);
                                string status =
                                    Convert.ToString(job["status"]);

                                LogTextBox.Text +=
                                    DateTime.Now.ToLongTimeString() +
                                    ": " + status + "\n";

                                if (status == "success")
                                {
                                    // Prefer the completed job's output URL.
                                    string completedUrl =
                                        Convert.ToString(job["url"]);

                                    if (!String.IsNullOrWhiteSpace(completedUrl))
                                    {
                                        resultFileUrl = completedUrl;
                                    }

                                    if (String.IsNullOrWhiteSpace(resultFileUrl))
                                    {
                                        throw new InvalidOperationException(
                                            "The job completed without an output URL."
                                        );
                                    }

                                    // 5. Download and display the JSON result.
                                    using (WebClient downloadClient =
                                        new WebClient())
                                    {
                                        downloadClient.Encoding =
                                            Encoding.UTF8;

                                        ResultTextBox.Text =
                                            downloadClient.DownloadString(
                                                resultFileUrl
                                            );
                                    }

                                    LogTextBox.Text +=
                                        "Generated JSON successfully.\n";
                                    break;
                                }

                                if (status == "working")
                                {
                                    Thread.Sleep(3000);
                                    continue;
                                }

                                LogTextBox.Text +=
                                    "Job ended with status: " + status + "\n";

                                string message =
                                    Convert.ToString(job["message"]);

                                if (!String.IsNullOrWhiteSpace(message))
                                {
                                    LogTextBox.Text += message + "\n";
                                }

                                break;
                            }
                        }
                        else
                        {
                            LogTextBox.Text +=
                                Convert.ToString(json["message"]) + "\n";
                        }
                    }
                    else
                    {
                        LogTextBox.Text +=
                            Convert.ToString(json["message"]) + "\n";
                    }
                }
            }
            catch (Exception ex)
            {
                LogTextBox.Text += ex.Message + "\n";
            }

            LogTextBox.Text += "Done.\n";
        }

        private JObject CheckJobStatus(string jobId)
        {
            using (WebClient webClient = new WebClient())
            {
                webClient.Encoding = Encoding.UTF8;
                webClient.Headers.Add("x-api-key", API_KEY);

                string url =
                    "https://api.pdf.co/v1/job/check?jobid=" +
                    Uri.EscapeDataString(jobId);

                string response = webClient.DownloadString(url);
                return JObject.Parse(response);
            }
        }
    }
}

Source Code at GitHub

You can explore the full source code for this sample at this GitHub link.

Extract Invoices – Sample Screenshots