Question

This assignment attempts to model the social phenomenon twitter. It involves two main classes: Tweet and TweetManager. You will load a set of tweets from a local file into a List collection. You will perform some simple queries on this collection.

The Tweet and the TweetManager classes must be in separate files and must not be in the Program.cs file.

The Tweet Class

The Tweet class consist of nine members that include two static ones (the members decorated with the $ symbol). You will implement this and all of the classes in Visual Studio. A short description of the class members is given below:

Tweet Class Fields - $ CURRENT_ID : int Properties + From : string «set absent» + To : string «set absent» + Body : string «set absent» + Tag : string «set absent» + Id : string «set absent» Methods + Tweet(from : string, to : string, body : string tag : string) + ToString() : string +$ Parse(line : string) : Tweet

The $ symbol is used to denote that this member belongs to the type rather than a specific object.

Fields:

1. CURRENT_ID – this private field is a class variable, it represents the number to be used in setting the id of this tweet.

Properties:

1. All of the properties are readonly and and are self-explanatory.

From – this property is a string representing the originator of this tweet. The getter is public and the setter is absent.

2. To – this property is a string representing the intended recipient of this tweet. The getter is public and the setter is absent.

3. Body – this property is a string representing the actual message body of this tweet. The getter is public and the setter is absent.

4. Tag – this property is a string representing the hash tag of this tweet. The getter is public and the setter is absent.

5. Id – this property is a string representing the id of this tweet. The getter is public and the setter is absent. This is used to uniquely identify a tweet.

Methods:

1. public Tweet(string from, string to, string body, string tag) – This public constructor takes four string parameters. This constructor does the following:

1. Assigns the arguments to the appropriate properties.

2. Sets the Id property using the class variable CURRENT_ID.

3. After the Id property is set, the CURRENT_ID is then incremented so that the next assignment will be unique. (see description of Id above)

2. public override string ToString() – This method overrides the same method of the Object class. It does not take any parameter but return a string representation of itself. You decide on the format for the output. You should also consider outputting only part of the Body. Use the Substring() method of the string class to do this.

3. public static Tweet Parse(string line) – This is a public class method that takes a string argument and returns a Tweet object. It is used to create a Tweet object when loading the tweets from a file. The argument represents a single line of input read from the file. This method does the following:

a. Uses the method of the string class is to chunk the input into four strings. The default delimiter for the Split() method is a space, however in this case the delimiter should be a tab. To specify an argument use the following code: Split(new char[]{' '});

b. Invokes the constructor with the four arguments Return the

c. result of the above invocation

The TweetManager Class

This static class consist of five static members. You will also implement this in Visual Studio. A short description of the class members is given below:

Fields:

1. TWEETS – this private field is a class variable, it is a collection of all the tweets in the system. It is initialized in the static constructor. It is populated in the static constructor.

2. FILENAME – this private field is a class variable, it represents the name of the file that contains all the tweets. It is used in the static constructor to read in the tweets. You will have to set this to the name of file that has the information about the tweets.

Methods:

1. static TweetManager() – This is the static constructor. It does not require any parameter. This constructor does the following:

a. Initialize the tweets field to a new list of tweets
b. Opens the file specified by the filename field for reading

c. Using a looping structure it does the following:

1. Reads one line from the file

2. Passes this line to the static Parse() method of the Tweet class to create a

   tweet object

3. The resulting object is added to the tweet collection

   1. This is repeated until the input from the file is empty (null).

      2. public static void Initialize() – This class method it used to facilitate the development of this project. It will not be used in the production code, just while developing. This method does the following:

      a. Creates about 5 tweets objects and add them to the tweet collection.

      3. public static void ShowAll() – This is a public class method that does not take any argument that does not return a value.

      4. public static void ShowAll(string tag) – This is a public class method that takes a string argument that does not return a value. It display all the tweets with tag matching the argument.

      Testing

      In your test harness (the Main() method in the Program Class), write the code to test all the methods of the TweetManager class except the Initialize() method

Answer 1

Program code to copy

main.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;

namespace TweetApp
{
    class Program
    {
        static void Main(string[] args)
        {
            //TweetManager.ShowAll();
            TweetManager.ShowAll("taxes");
            TweetManager.ShowAll("Ford");
        }
    }
}

===================================================================================

Tweet.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace TweetApp
{
    class Tweet
    {
        //constant field
        private static int CURRENT_ID;
      
        //properties
        public string From {get; private set;}
        public string To {get; private set;}
        public string Body {get; private set;}
        public string Tag {get; private set;}
        public string Id {get; private set; }

        /*
            This public constructor takes four string parameters. This constructor does the following:
            a.   Assigns the arguments to the appropriate properties.
            b.   Sets the Id property using the class variable CURRENT_ID.
            c.   After the Id property is set
         */

        public Tweet(string from, string to, string body, string tag)
        {
            From = from;
            To = to;
            Body = body;
            Tag = tag;
            Id = ""+ CURRENT_ID;
            CURRENT_ID++;
        }

        /*
        This method overrides the same method of the Object class.
       */
        public override string ToString()
        {
            return string.Format("ID: {0}\nFrom: {1}\nTo: {2}\nBody: {3}...\nTag: {4}",
                Id, From, To, Body.Substring(0, Body.Length), Tag);
        }

        /*
         * This is a public class method that takes a string argument and returns a Tweet object.
         * It is used to create a Tweet object when loading the tweets from a file.
        */
        public static Tweet Parse(string line)
        {
            string[] tweetParam = line.Split('\t');
            Tweet tweetLine = new Tweet(tweetParam[1], tweetParam[2], tweetParam[3], tweetParam[0]);
            return tweetLine;
        }

    }
}

===================================================================================

TweetManager.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;

namespace TweetApp
{
    static class TweetManager
    {
        /*
         * Private fields to stop List of Tweets and filename
         */
        private static List<Tweet> tweets;
        private static string filename = @"TweetFile.txt";

        /*
         * This is the static constructor. It does not require any parameter.
         * This constructor does the following:
         * a.   Initialize the tweets field to a new list of tweets
         * b.   Opens the file specified by the filename field for reading
         * c.   Using a looping structure it does the following:
         * i.   Reads one line from the file
         * ii.   Passes this line to the static Parse() method of the Tweet class to create a tweet object
         * iii.The resulting object is added to the tweet collection
         * iv.   This is repeated until the input from the file is empty (null).
         */
        static TweetManager()
        {
            tweets = new List<Tweet>();
            using (TextReader reader = new StreamReader(filename))
            {
                string line = reader.ReadLine();
                while (line != null)
                {
                    tweets.Add(Tweet.Parse(line));
                    line = reader.ReadLine();
                }
            }
        }

        /*
         * This class method it used to facilitate the development of this project.
         * It will not be used in the production code. This method does the following:
         * a.   Creates about 5 tweets objects and add them to the tweet collection.
         */
        public static void Initialize(string line)
        {
            tweets.Add(Tweet.Parse("Ford   Trudeau   Bieber   Go Raptors! Go!"));
            tweets.Add(Tweet.Parse("WeTheNorth   Drake   Obama   Go Raptors! Go!"));
            tweets.Add(Tweet.Parse("Raptors   Tory   Drake   Yes Toronto will get them!"));
            tweets.Add(Tweet.Parse("Ford   Trudeau   Obama   Toronto joins cities around the world to celebrate International Day Against Homophobia & Transphobia"));
            tweets.Add(Tweet.Parse("Ford   Drake   Bieber   Go Raptors! Go!"));
        }

        /*
         * This is a public class method that does not take any argument that
         * does not return a value. It display all the tweets matching this tag.
         */
        public static void ShowAll()
        {
            foreach (Tweet tweet in tweets)
            {
                Console.WriteLine("{0}\n\n", tweet);
            }
        }

        /*
         * This is a public class method that takes a string argument
         * that does not return a value. It display all the tweets matching this tag.
         */
        public static void ShowAll(string tag)
        {
            Console.WriteLine("Tweet with {0} tag", tag);
            Console.WriteLine("---------------------");
            foreach (Tweet tweet in tweets)
            {
                if (tweet.Tag.ToLower() == tag.ToLower())
                {
                    Console.WriteLine ("{0}\n",tweet);
                }
            }
        }
    }
}

===================================================================================

TweetFile.txt

Raptors   Drake   Obama   Go Raptors! Go!
Raptors   Tory   Drake   Yes Toronto will get them!
Raptors   Tory   Obama   Toronto joins cities around the world to celebrate International Day Against Homophobia & Transphobia
Taxes   Drake   Bieber   Go Raptors! Go!
Raptors   Drake   Obama   Go Raptors! Go!
Raptors   Tory   Drake   Yes Toronto will get them!
Raptors   Tory   Obama   Toronto joins cities around the world to celebrate International Day Against Homophobia & Transphobia
Ford   Trudeau   Bieber   Go Raptors! Go!
WeTheNorth   Drake   Obama   Go Raptors! Go!
Raptors   Tory   Drake   Yes Toronto will get them!
Ford   Trudeau   Obama   Toronto joins cities around the world to celebrate International Day Against Homophobia & Transphobia
Ford   Drake   Bieber   Go Raptors! Go!

==================================================================================

Program Screenshot

main.cs

main.cs Tweet.cs TweetManager.cs TweetFile.txt 3 4 inc using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.IO; 7 8 10 namespace TweetApp 11- { class Program static void Main(string[] args) //TweetManager. ShowAll(); TweetManager. ShowAll("taxes"); TweetManager. ShowAll("Ford");

===================================================================================

Tweet.cs

TweetFile.txt main.cs Tweet.cs TweetManager.cs 1- using System; using System.Collections.Generic; using System.Linq; 4 using System.Text; 5 using System.Threading.Tasks; namespace TweetApp 8- class Tweet 10 - //constant field private static int CURRENT_ID; //properties public string From {get; private set;} public string To get; private set;} public string Body {get; private set;} public string Tag (get; private set;} public string Id {get; private set; } This public constructor takes four string parameters. This constructor does the following: a. Assigns the argument to the appropriate properties. b. Sets the Id property using the class variable CURRENT ID. c. After the Id property is set public Tweet(string from, string to, string body, string tag) From = from; To = to; Body = body; Tag = tag: Id = ""+ CURRENT_ID; CURRENT_ID++; This method overrides the same method of the object class.

main.cs Tweet.cs TweetManager.cs TweetFile.txt This public constructor takes four string parameters. This constructor does the following: a. Assigns the arguments to the appropriate properties. b. Sets the Id property using the class variable CURRENT_ID. C. After the Id property is set public Tweet(string from, string to, string body, string tag) From = from; To = to; Body = body; Tag = tag: Id = ""+ CURRENT_ID; CURRENT_ID++; This method overrides the same method of the object class. public override string ToString() return string.Format("ID: {0}\nFrom: {1}\nTo: {2}\nBody: {3}... InTag: {4}", Id, From, To, Body. Substring(0, Body.Length), Tag); * This is a public class method that takes a string argument and returns a Tweet object. * It is used to create a Tweet object when loading the tweets from a file. */ public static Tweet Parse(string line) string[] tweetParam = line. Split('\t'); Tweet tweetLine = new Tweet(tweetParam[1], tweetParam[2], tweetParam[3], tweetParam[@]); return tweetLine; 58 } 59}

==================================================================================

TweetManager.cs

TweetFile.txt main.cs Tweet.cs TweetManager.cs 1- using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using System.Threading.Tasks; 6 using System.IO; namespace TweetApp static class TweetManager * Private fields to stop List of Tweets and filename private static List<Tweet> tweets; private static string filename = @"TweetFile.txt"; * This is the static constructor. It does not require any parameter. * This constructor does the following: *a. Initialize the tweets field to a new list of tweets * b. Opens the file specified by the filename field for reading *c. Using a looping structure it does the following: * i. Reads one line from the file * ii. Passes this line to the static Parse() method of the Tweet class to create a tweet object * iii. The resulting object is added to the tweet collection * iv. This is repeated until the input from the file is empty (null). static TweetManager() tweets = new List<Tweet>(); using (TextReader reader = new StreamReader(filename)) string line = reader.ReadLine(); while (line != null) tweets.Add(Tweet.Parse(line)); line = reader.ReadLine();

main.cs Tweet.cs TweetManager.cs TweetFile.txt line = reader.ReadLine(); 38 40 * This class method it used to facilitate the development of this project. * It will not be used in the production code. This method does the following: * a. Creates about 5 tweets objects and add them to the tweet collection. public static void Initialize(string line) tweets.Add(Tweet.Parse("Ford Trudeau Bieber Go Raptors! Go!")); tweets.Add(Tweet.Parse("We The North Drake Obama Go Raptors! Go!")); tweets. Add (Tweet.Parse("Raptors Tory Drake Yes Toronto will get them!")); tweets.Add(Tweet.Parse("Ford Trudeau Obama Toronto joins cities around the world to tweets.Add(Tweet.Parse("Ford Drake Bieber Go Raptors! Go!")); * This is a public class method that does not take any argument that * does not return a value. It display all the tweets matching this tag. */ public static void ShowAll() foreach (Tweet tweet in tweets) Console.WriteLine("{0}\n\n", tweet); * This is a public class method that takes a string argument * that does not return a value. It display all the tweets matching this tag. public static void ShowAll(string tag) Console.WriteLine("Tweet with {0} tag", tag);

main.cs Tweet.cs TweetManager.cs: TweetFile.txt tweets. Add (Tweet.Parse("Ford Trudeau Bieber Go Raptors! Go!")); tweets.Add(Tweet.Parse("We TheNorth Drake Obama Go Raptors! Go!")); otors Tory Drake Yes Toronto will get them!")); tweets. Add (Tweet.Parse("Ford Trudeau Obama Toronto joins cities around the world to celebrate International Day Against Homophobi tweets.Add(Tweet.Parse("Ford Drake Bieber Go Raptors! Go!")); /* * This is a public class method that does not take any argument that * does not return a value. It display all the tweets matching this tag. */ public static void ShowAll() foreach (Tweet tweet in tweets) { Console.WriteLine("{0}\n\n", tweet); * This is a public class method that takes a string argument * that does not return a value. It display all the tweets matching this tag. public static void showAll(string tag) Console.WriteLine("Tweet with {0} tag", tag); Console.WriteLine("--------- foreach (Tweet tweet in tweets) ----------"): if (tweet. Tag. Tolower() == tag. ToLower()) Console.WriteLine("{0}\n", tweet);

================================================================================

TweetFile.txt

main.cs Tweet.cs TweetManager.cs TweetFile.txt 1 Raptors Drake Obama Go Raptors! Go! 2 Raptors Tory Drake Yes Toronto will get them! 3 Raptors Tory Obama Toronto joins cities around the world to celebrate International Day Against Homophobia & Transphobia 4 Taxes Drake Bieber Go Raptors! Go! 5 Raptors Drake Obama Go Raptors! Go! 6 Raptors Tory Drake Yes Toronto will get them! 7 Raptors Tory Obama Toronto joins cities around the world to celebrate International Day Against Homophobia & Transphobia 8 Ford Trudeau Bieber Go Raptors! Go! 9 WeTheNorth Drake Obama Go Raptors! Go! 10 Raptors Tory Drake Yes Toronto will get them! 11 Ford Trudeau Obama Toronto joins cities around the world to celebrate International Day Against Homophobia & Transphobia 12 Ford Drake Bieber Go Raptors! Go!

===================================================================================

Sample output

input Tweet with taxes tag --------------------- ID: 3 From: Drake To: Bieber Body: Go Raptors! Go!... Tag: Taxes Tweet with Ford tag - --------- --------- -- ID: 7 From: Trudeau To: Bieber Body: Go Raptors! Go!... Tag: Ford ID: 10 From: Trudeau To: Obama Body: Toronto joins cities around the world to celebrate International Day Against Homophobia & Transphobia... Tag: Ford ID: 11 From: Drake To: Bieber Body: Go Raptors! Go!... Tag: Ford