Wednesday, April 13, 2016

ASP.Net C# Retrieving a list of videos from a YouTube playlist

Matt Pavey April 13, 2016 .Net, Bootstrap 5 comments

Recently when working on my favorites page, as I was typing up my favorite songs and linking them to YouTube, I thought it would be pretty nice to just tap in to my "Favorites" list directly in YouTube. A quick Google search lead me to this Stack Overflow article:

http://stackoverflow.com/questions/34143202/get-all-videos-from-channel-youtube-api-v3-c-sharp

So building off of a couple of the answers in this article, I've put together a functional example using C# to show how to connect to the YouTube Data API.

For this example we'll be using the following NuGet package:

Google.Apis.YouTube.v3 Client Library

If you need to generate your own YouTube Data API key, you can visit the Google Developer Console and use the API Manager.

ASPX Page

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="default.aspx.cs" Inherits="Web.youtube._default" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <!-- title -->
    <title>YouTube Demo</title>
 
    <!-- bootstrap -->
    <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" />
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>

    <!-- styles -->
    <style>
        body { margin: 25px !important; }
        .video { margin-top: 25px; }
        .video .title { font-weight: normal; white-space: nowrap; overflow: hidden; }
        .video .thumbnail img { width: 192px; height: 144px; }
    </style>
</head>

<body>
    <form id="form1" runat="server">
        <div class="container">
            <div class="col-lg-12">
                <h1>YouTube Demo</h1>
            </div>
            
            <!-- placeholder where we will render the results -->
            <asp:PlaceHolder ID="pnlVideos" runat="server" />

            <div class="col-lg-12" style="padding-top: 10px">
                <asp:Label ID="lblMessage" Font-Bold="true" ForeColor="Red" ClientIDMode="Static" runat="server" />
            </div>
        </div>

        <!-- template to help build each video container -->
        <asp:Literal ID="lblTemplate" Visible="false" runat="server">
            <div class="video col-lg-4">
                <div class="title">
                    <a href="{Url}" target="_blank">
                        {Title}
                    </a>
                </div>

                <div class="thumbnail">
                    <a title="{ToolTip}" href="{Url}" target="_blank">
                        <img title="{ToolTip}" src="{Image}" alt="" />
                    </a>
                </div>
            </div>
        </asp:Literal>
    </form>
</body>
</html>

Code-Behind

using Google.Apis.Services;
using Google.Apis.YouTube.v3;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Web.youtube
{
    public partial class _default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            try
            {
                // initialize call to the youtube service
                var YouTubeService = new YouTubeService(new BaseClientService.Initializer() { ApiKey = "YourApiKey" });

                // indicate the parts we need for the request
                var ChannelListRequest = YouTubeService.Channels.List("contentDetails");

                // indicate the username for the channel you are requesting
                ChannelListRequest.ForUsername = "UserNameOfChannelYouAreRequesting";
                
                // execute the request and get the response
                var ListResponse = ChannelListRequest.Execute();

                // iterate through the results
                foreach (var channel in ListResponse.Items)
                {
                    // indicate the list you are requesting
                    // if your favorites list is unlisted you will need to explicitly set this value
                    // var ListId = channel.ContentDetails.RelatedPlaylists.Favorites;
                    var ListId = "YouTubeListId";

                    // the page token will be used if the results span multiple pages
                    var PageToken = "";

                    // iterate until there is no more data
                    while (PageToken != null)
                    {
                        // indicate the parts we need for the request
                        var PlaylistRequest = YouTubeService.PlaylistItems.List("snippet");

                        // playlist request properties
                        PlaylistRequest.PlaylistId = ListId;
                        PlaylistRequest.MaxResults = 50;
                        PlaylistRequest.PageToken = PageToken;

                        // execute the request and get the response
                        var PlaylistResponse = PlaylistRequest.Execute();

                        // iterate through the results
                        foreach (var Video in PlaylistResponse.Items)
                        {
                            // variables
                            string Template = lblTemplate.Text;
                            string VideoId = Video.Snippet.ResourceId.VideoId;
                            string Title = Video.Snippet.Title;
                            string Url = string.Format("https://www.youtube.com/watch?v={0}", VideoId);
                            string Image = Video.Snippet.Thumbnails.High.Url;

                            // replace placeholders
                            Template = Template.Replace("{VideoId}", VideoId);
                            Template = Template.Replace("{Title}", Title);
                            Template = Template.Replace("{Url}", Url);
                            Template = Template.Replace("{Image}", Image);
                            Template = Template.Replace("{ToolTip}", HttpUtility.HtmlEncode(Title));

                            // add to videos panel
                            pnlVideos.Controls.Add(new LiteralControl(Template));
                        }

                        // get the next page token
                        PageToken = PlaylistResponse.NextPageToken;
                    }
                }
            }
            catch (Exception ex)
            {
                lblMessage.Text = ex.Message;
            }
        }
    }
}

Click here to see a fully functional demo.

Matt Pavey is a Microsoft Certified software developer who specializes in ASP.Net, VB.Net, C#, AJAX, LINQ, XML, XSL, Web Services, SQL, jQuery, and more. Follow on Twitter @matthewpavey

Monday, April 11, 2016

ASP.Net C# DownloadString vs DownloadData Encoding Examples

Matt Pavey April 11, 2016 .Net, MySafeInfo No comments

I recently came across an issue using the WebClient.DownloadString method in System.Net that was causing UTF8 encoded data to not come through properly, and instead was showing odd characters.

Researching the issue led me to the following Stack Overflow articles:

The accepted answers on both work well, so I've put together a functional example using C# to illustrate the behavior and results.

DownloadString (no encoding specified)

// variables
string Url = "https://mysafeinfo.com/api/data?list=states&format=json&alias=nm=name,ab=code,cp=capital,yr=year&select=capital&ab=GU";
  
// DownloadString (no encoding specified)
using (WebClient client = new WebClient())
{
    Console.WriteLine(client.DownloadString(Url));
}

// result
[
  {
    "capital": "HagÃ¥tÃ±a Dededo"
  }
]

DownloadString (encoding specified)

// variables
string Url = "https://mysafeinfo.com/api/data?list=states&format=json&alias=nm=name,ab=code,cp=capital,yr=year&select=capital&ab=GU";
  
// DownloadString (encoding specified)
using (WebClient client = new WebClient())
{
    // specify encoding
    client.Encoding = System.Text.UTF8Encoding.UTF8;
   
    // output
    Console.WriteLine(client.DownloadString(Url));
}

// result
[
  {
    "capital": "Hagåtña Dededo"
  }
]

DownloadData (encoding specified)

// variables
string Url = "https://mysafeinfo.com/api/data?list=states&format=json&alias=nm=name,ab=code,cp=capital,yr=year&select=capital&ab=GU";
  
// DownloadData (encoding specified)
using (WebClient client = new WebClient())
{
    Console.WriteLine(System.Text.UTF8Encoding.UTF8.GetString(client.DownloadData(Url)));
}

// result
[
  {
    "capital": "Hagåtña Dededo"
  }
]

Sunday, April 10, 2016

ASP.Net C# Exporting and Importing Excel Data

Matt Pavey April 10, 2016 .Net, JSON, MySafeInfo No comments

Here is a simple example using C# to export data to an Excel file and to read data from an Excel file. This example demonstrates the following:

- MySafeInfo Data API
- Json.NET (Newtonsoft.Json)
- EPPlus
- Response.BinaryWrite
- WebClient.DownloadData
- StreamReader
- Serialization
- Custom Extension Methods

Code-Behind

using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Utilities;

namespace Web.excel
{
    public partial class _default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            // empty
        }

        public void DownloadFile(byte[] Data, string FileType = "application/csv", string FileName = "data.csv")
        {
            // headers
            Response.BufferOutput = true;
            Response.ClearHeaders();

            // explicitly append preamble for csv files so excel recognizes utf-8 encoding
            if (FileType.ToLower().Contains("csv"))
            {
                Response.BinaryWrite(System.Text.Encoding.UTF8.GetPreamble());
            }

            // encoding
            Response.ContentEncoding = System.Text.Encoding.UTF8;

            // content type
            Response.ContentType = FileType;

            // content disposition
            Response.AddHeader("Content-Disposition", string.Format("attachment; filename=\"{0}\"", FileName));

            // data
            Response.BinaryWrite(Data);

            // end
            Response.End();
        }

        protected void btnDownload_Click(object sender, EventArgs e)
        {
            // variables
            string Result = string.Empty;
            string Url = "https://mysafeinfo.com/api/data?list=states&format=json&alias=nm=name,ab=code,cp=capital,yr=year";
            List<State> States = new List<State>();
            DataTable DT = new DataTable();
            byte[] Data = null;

            // download json data
            using (WebClient client = new WebClient())
            {
                Result = System.Text.UTF8Encoding.UTF8.GetString(client.DownloadData(Url));
            }

            // deserialize json data into a List<State>
            // Json.NET (Newtonsoft.Json)
            // https://www.nuget.org/packages/Newtonsoft.Json
            States = Newtonsoft.Json.JsonConvert.DeserializeObject<List<State>>(Result);

            // convert List<State> to a DataTable using ToDataTable extension method
            DT = States.ToDataTable();

            // convert DataTable to byte[] using ToExcel extension method 
            // EPPlus
            // https://www.nuget.org/packages/EPPlus
            Data = DT.ToExcel(WorksheetName: "States");

            // download excel file
            DownloadFile(Data: Data, FileType: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", FileName: "states.xlsx");
        }

        protected void btnUpload_Click(object sender, EventArgs e)
        {
            // variables
            DataTable DT = new DataTable();
            List<State> States = new List<State>();

            // read excel file in to a StreamReader
            using (StreamReader sr = new StreamReader(Server.MapPath("states.xlsx")))
            {
                // read the underlying stream and convert to a DataTable using ToDataTable extension method
                DT = sr.BaseStream.ToDataTable(HasHeader: true);
            }

            // convert DataTable to a List<State> using ToList extension method
            States = DT.ToList<State>().ToList();

            // output serialized List<State> so we can see that the excel file was read successfully
            lblOutput.Text = States.Serialize();

            // show panel
            pnlOutput.Visible = true;
        }

        // state class
        public class State
        {
            public State()
            {
                Name = string.Empty;
                Code = string.Empty;
                Capital = string.Empty;
                Year = string.Empty;
            }

            public string Name { get; set; }
            public string Code { get; set; }
            public string Capital { get; set; }
            public string Year { get; set; }
        }
    }
}

ASPX Page

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="default.aspx.cs" Inherits="Web.excel._default" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <!-- title -->
    <title>Excel Demo</title>

    <!-- jquery -->
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>

    <!-- bootstrap -->
    <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" />
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>

    <!-- custom style -->
    <style>
        body {
            margin: 25px !important;
        }

        .form-group {
            width: 800px;
        }
    </style>
</head>

<body>
    <form id="form1" runat="server">
    <div>
        <p>
            <asp:Button ID="btnDownload" Text="Download Excel File" CssClass="btn btn-default" Width="200px" OnClick="btnDownload_Click" ClientIDMode="Static" runat="server" />
        </p>

        <p>
            <asp:Button ID="btnUpload" Text="Read Excel File" CssClass="btn btn-default" Width="200px" OnClick="btnUpload_Click" ClientIDMode="Static" runat="server" />
        </p>

        <asp:PlaceHolder ID="pnlOutput" Visible="false" runat="server">
            <p>
                <pre><asp:Literal ID="lblOutput" runat="server" /></pre>
            </p>
        </asp:PlaceHolder>
    </div>
    </form>
</body>
</html>

Extensions

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.Data;
using System.Xml.Serialization;
using System.IO;
using System.Collections.Specialized;
using System.Web;
using System.ComponentModel;
using System.Xml;
using System.Xml.Linq;
using System.Web.UI;
using System.Text.RegularExpressions;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Linq.Expressions;
using System.Net;
using OfficeOpenXml;

namespace Utilities
{
    public static class Extensions
    {
        private static Dictionary<Type, IList<PropertyInfo>> typeDictionary = new Dictionary<Type, IList<PropertyInfo>>();

        public static IList<PropertyInfo> GetPropertiesForType<T>()
        {
            //variables
            var type = typeof(T);

            //get types
            if (!typeDictionary.ContainsKey(typeof(T)))
            {
                typeDictionary.Add(type, type.GetProperties().ToList());
            }

            //return
            return typeDictionary[type];
        }

        public static T ToObject<T>(this DataRow row) where T : new()
        {
            //variables
            IList<PropertyInfo> properties = GetPropertiesForType<T>();

            //return
            return CreateItemFromRow<T>(row, properties);
        }

        public static IList<T> ToList<T>(this DataTable table) where T : new()
        {
            //variables
            IList<T> result = new List<T>();

            //foreach
            foreach (DataRow row in table.Rows)
            {
                result.Add(row.ToObject<T>());
            }

            //return
            return result;
        }

        private static T CreateItemFromRow<T>(DataRow row, IList<PropertyInfo> properties) where T : new()
        {
            //variables
            T item = new T();

            //foreach
            foreach (var property in properties)
            {
                //make sure a column exists in the table with this property name
                if (row.Table.Columns.Contains(property.Name))
                {
                    //get the value from the current data row
                    object value = row[property.Name];

                    //set property accordingly
                    if (value != null & value != DBNull.Value)
                    {
                        SetProperty<T>(item, property.Name, value);
                    }
                }
            }

            //return
            return item;
        }

        public static string GetProperty<T>(this T obj, string Property)
        {
            //reflection
            PropertyInfo propertyInfo = obj.GetType().GetProperty(Property, BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);
            object property = null;

            //make sure property is valid
            if (propertyInfo != null)
            {
                property = propertyInfo.GetValue(obj, null);
            }

            //return value
            if (property != null)
            {
                return property.ToString();
            }
            else
            {
                return string.Empty;
            }
        }

        public static T SetProperty<T>(this T obj, string Property, object Value)
        {
            //reflection
            PropertyInfo prop = obj.GetType().GetProperty(Property, BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);

            //trim strings
            if (Value.GetType() == typeof(string))
            {
                Value = Value.ToString().Trim();
            }

            //make sure property is valid
            if (prop != null && prop.CanWrite)
            {
                prop.SetValue(obj, Value, null);
            }

            //return
            return obj;
        }

        public static string Serialize<T>(this T obj)
        {
            // Json.NET (Newtonsoft.Json)
            // https://www.nuget.org/packages/Newtonsoft.Json
            return Newtonsoft.Json.JsonConvert.SerializeObject(obj, Newtonsoft.Json.Formatting.Indented);
        }

        public static T Deserialize<T>(string data) where T : new()
        {
            // Json.NET (Newtonsoft.Json)
            // https://www.nuget.org/packages/Newtonsoft.Json
            return Newtonsoft.Json.JsonConvert.DeserializeObject<T>(data);
        }

        public static DataTable ToDataTable<T>(this IList<T> data)
        {
            // variables
            PropertyDescriptorCollection Properties = TypeDescriptor.GetProperties(typeof(T));
            object[] values = new object[Properties.Count];
            DataTable DT = new DataTable();

            // columns
            foreach (PropertyDescriptor PropertyInfo in Properties)
            {
                // data column
                DataColumn DataColumn = new DataColumn();

                // name
                DataColumn.ColumnName = PropertyInfo.Name;

                // data type
                if (PropertyInfo.PropertyType.Name.Contains("Nullable"))
                {
                    DataColumn.DataType = typeof(String);
                }
                else
                {
                    DataColumn.DataType = PropertyInfo.PropertyType;
                }

                // add to table
                DT.Columns.Add(DataColumn);
            }

            // rows
            foreach (T item in data)
            {
                for (int i = 0; i < values.Length; i++)
                {
                    values[i] = Properties[i].GetValue(item);
                }
                DT.Rows.Add(values);
            }

            // return
            return DT;
        }

        public static bool HasValue(this string Value)
        {
            return !Value.IsBlank();
        }

        public static bool IsBlank(this string Value)
        {
            bool ReturnValue = true;

            if (Value != null)
            {
                ReturnValue = Value.Trim().Length == 0;
            }

            return ReturnValue;
        }

        public static byte[] ToExcel(this DataTable DT, string WorksheetName = "Data", bool AutoFormatDates = false)
        {
            // EPPlus
            // https://www.nuget.org/packages/EPPlus

            // variables
            byte[] Data = null;
            ExcelPackage ExcelPackage = new ExcelPackage();
            ExcelWorksheet ExcelWorksheet = ExcelPackage.Workbook.Worksheets.Add(WorksheetName.HasValue() ? WorksheetName : "Data");

            // load data table with column headings
            ExcelWorksheet.Cells["A1"].LoadFromDataTable(DT, true);

            // auto-format dates
            if (AutoFormatDates)
            {
                var DateColumns = from DataColumn d in DT.Columns where d.DataType == typeof(DateTime) || d.ColumnName.Contains("Date") select d.Ordinal + 1;

                foreach (var Column in DateColumns)
                {
                    ExcelWorksheet.Cells[2, Column, DT.Rows.Count + 1, Column].Style.Numberformat.Format = "mm/dd/yyyy";
                }
            }

            // get data as byte array
            Data = ExcelPackage.GetAsByteArray();

            // cleanup
            ExcelPackage.Dispose();

            // return byte array
            return Data;
        }

        public static DataTable ToDataTable(this Stream Data, bool HasHeader = true)
        {
            // EPPlus
            // https://www.nuget.org/packages/EPPlus

            // variables
            DataTable DT = new DataTable();
            var RowStart = HasHeader ? 2 : 1;

            using (ExcelPackage ExcelPackage = new ExcelPackage())
            {
                // load data from stream
                ExcelPackage.Load(Data);

                // worksheet
                ExcelWorksheet ExcelWorksheet = ExcelPackage.Workbook.Worksheets.First();

                // create column headings
                foreach (var Cell in ExcelWorksheet.Cells[1, 1, 1, ExcelWorksheet.Dimension.End.Column])
                {
                    DT.Columns.Add(HasHeader ? Cell.Text : string.Format("Column {0}", Cell.Start.Column));
                }

                // copy data from each row to the data table
                for (int RowNumber = RowStart; RowNumber <= ExcelWorksheet.Dimension.End.Row; RowNumber++)
                {
                    // variables
                    ExcelRange Row = ExcelWorksheet.Cells[RowNumber, 1, RowNumber, ExcelWorksheet.Dimension.End.Column];
                    DataRow DataRow = DT.NewRow();

                    // copy the data from each cell to the data row
                    foreach (ExcelRangeBase cell in Row)
                    {
                        DataRow[cell.Start.Column - 1] = cell.Text;
                    }

                    // add row to data table
                    DT.Rows.Add(DataRow);
                }
            }

            // return data table
            return DT;
        }
    }
}

Matthew Pavey's Blog

Matthew Pavey is a follower of Christ, devoted husband and father, avid reader, and software developer.