Criando um sistema básico de Short Url (parte 2)

Depois de vários meses usando o sistema e tendo que atualizar a lista de links manualmente no XML via FTP, decidi que era hora de melhorar o sistema para que incluísse um banco de dados e um meio de incluir, editar e remover links online.

Portanto, melhorei o sistema e hoje está disponível em http://puul.ga

O código fonte (open source) está disponível no Github

Foram feitas várias melhorias no sistema, de forma a ser responsivo e fácil de usar. Mas seu visual e utilidades continuam simples. Cria-se um short link (mesmo conceito que bit.ly) que pode ser compartilhado em qualquer lugar, deixando o link curto e fácil de ser digitado.

O projeto continua sendo em C#, MVC, Entity Framework, Html5, Css3 e jQuery (Bootstrap)

Primeiramente, é necessário criar o objeto/classe que irá conter os dados do Link gerado:

using System;
using System.ComponentModel.DataAnnotations;

namespace Shorten_Urls.Models
{
    public class Url
    {
        public int Id { get; set; }
        [RegularExpression(@"^.{8,}$", ErrorMessage = "Minimum 8 characters required")]
        [Required(ErrorMessage = "Required")]
        [StringLength(30, MinimumLength = 8, ErrorMessage = "Invalid")]
        [Display(Name ="Shareable Url")]
        public string Src { get; set; }
        [Url]
        [Display(Name = "Redirects To")]
        public string Redirect { get; set; }
        public string UserId { get; set; }
        [Display(Name = "Created By")]
        public string Username { get; set; }
        //[DataType(DataType.Date)]
        //[DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}", ApplyFormatInEditMode = true)]
        [Display(Name = "Created On")]
        public DateTime CreatedOn { get; set; }
        //[DataType(DataType.Date)]
        //[DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}", ApplyFormatInEditMode = true)]
        [Display(Name = "Expires")]
        public DateTime? Expires { get; set; }
    }
}

Também é necessário criar o Repositório (ou Data Layer). Esse repositório permite o uso tanto de XML quanto SQL, sendo configurada a opção no

web.config

using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;
using Microsoft.AspNet.Identity;
using System.Configuration;
using System.Data.Entity;

namespace Shorten_Urls.Models
{
    public class UrlRepository : IRepository<Url>
    {
        private XDocument _urls;
        private List<Url> urls;
        ApplicationDbContext _context;
        private readonly string DbProvider = ConfigurationManager.AppSettings["DbProvider"];
        private const string SQL = "Sql";
        private const string XML = "Xml";
        public bool needLastId { get { return DbProvider.Equals(XML); } }

        public List<Url> Urls { get { return urls; } }
        public int LastId
        { get { return urls.Last().Id; } }

        public UrlRepository()
        {
            urls = new List<Url>();

            if (DbProvider == XML)
            {
                _urls = MvcApplication.IO.Forwards;

                IEnumerable<XElement> rootDescendants = _urls.Descendants("url");
                foreach (XElement e in rootDescendants)
                    urls.Add(MapXElement(e));
            }
            else if (DbProvider == SQL)
            {
                _context = new ApplicationDbContext();
                urls = _context.Forwarders.ToList();
            }
        }

        public bool Exists(string src)
        {
            var yes = from y in urls where y.Src == src select y;
            if (yes.Count() > 0) return true;
            else return false;
        }

        public IEnumerable<Url> GetAll()
        {
            return urls;
        }

        public void Add(Url url)
        {
            urls.Add(url);
            if (DbProvider == XML)
                MvcApplication.IO.AddForward(url);
            else if (DbProvider == SQL)
            {
                _context.Forwarders.Add(url);
                _context.SaveChanges();
            }
        }
        public Url GetById(int Id)
        {
            Url e = (from url in urls where url.Id == Id select url).Single();
            if (DbProvider == SQL)
            {
                PopulateUsername(e);
            }
            return e;
        }
        public List<Url> GetByUserId(string userId)
        {
            List<Url> list = (from urlList in urls where urlList.UserId == userId select urlList).ToList();
            if (DbProvider == SQL)
            {
                foreach (Url url in list) PopulateUsername(url);
            }
            return list;
        }
        public Url GetBySrc(string src)
        {
            var e = (from url in urls where url.Src.Equals(src) select url);
            if (e.Count() == 0) return null;
            else {
                if (DbProvider == SQL)
                {
                    PopulateUsername(e.Single());
                }
                return e.Single();
            }
        }

        public void Remove(int id)
        {
            Url remove = (from url in urls where url.Id == id select url).Single();
            urls.Remove(remove);
            Remove(remove);
        }

        public void Remove(Url url)
        {
            urls.Remove(url);
            if (DbProvider == XML)
                MvcApplication.IO.RemoveForward(url);
            else if (DbProvider == SQL)
            {
                _context.Forwarders.Remove(url);
                _context.SaveChanges();
            }
        }

        public void Remove(string src)
        {
            Url remove = (from url in urls where url.Src == src select url).Single();
            urls.Remove(remove);
            Remove(remove);
        }

        public void RemoveAll()
        {
            urls.Clear();
        }

        public void RemoveByUserId(string userId)
        {
            Url remove = (from url in urls where url.UserId == userId select url).Single();
            urls.Remove(remove);
            Remove(remove);
        }

        public void Update(Url url)
        {
            Url old = (from urlE in urls where urlE.Id == url.Id select urlE).Single();
            urls.Remove(old);
            urls.Add(url);
            if (DbProvider == XML)
            {

                MvcApplication.IO.RemoveForward(old);
                MvcApplication.IO.AddForward(url);
            }
            else if (DbProvider == SQL)
            {
                _context.Entry(url).State = EntityState.Modified;
                _context.SaveChanges();
            }
        }


        private Url PopulateUsername(int id)
        {
            Url url = (from u in urls where u.Id == id select u).Single();
            string userId = url.UserId == null ? "" : url.UserId;
            UserRepository userRepo = new UserRepository();
            url.Username = userRepo.GetUsername(userId);
            return url;
        }
        private Url PopulateUsername(Url url)
        {
            UserRepository userRepo = new UserRepository();
            string userId = url.UserId == null ? "" : url.UserId;
            url.Username = userRepo.GetUsername(userId);
            return url;
        }
        private Url MapXElement(XElement element)
        {
            DateTime expires = element.Attribute("expires").Value == "" ? new DateTime(2999, 12, 31) : DateTime.Parse(element.Attribute("expires").Value);
            DateTime createdOn = element.Attribute("created").Value == "" ? DateTime.Now : DateTime.Parse(element.Attribute("created").Value);
            string userId = element.Attribute("userid").Value;
            int id = int.Parse(element.Attribute("id").Value);
            Url url = new Url
            {
                Id = id,
                CreatedOn = createdOn,
                Expires = expires,
                UserId = userId,
                Redirect = element.Value.Trim(),
                Src = element.Attribute("src").Value
            };
            return PopulateUsername(url);
        }
    }
}

A parte mais importante do projeto é o Controller que vai servir os Links, e as rotas de leitura dos links. Portanto, o

RouteConfig.cs

também tem que estar correto:

ForwardsController.cs

using Shorten_Urls.Models;
using System;
using System.Collections.Generic;
using System.Web.Mvc;
using System.Web.Script.Serialization;
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.EntityFramework;

namespace Shorten_Urls.Controllers
{
    public class ForwardsController : Controller
    {
        private UrlRepository _repo;
        private UserRepository _usersRepo;
        private ApplicationUser user;

        public ForwardsController()
        {
            _repo = new UrlRepository();
            _usersRepo = new UserRepository();
        }
        //
        // GET: /Forwards/

        public ActionResult SendToSrc(string src)
        {
            string error404 = "404.html";
            string redirect = "/Home/Index";

            Url url = _repo.GetBySrc(src);
            if (url != null)
            {

                if (!url.Redirect.Equals(string.Empty) && (url.Expires > DateTime.Now || url.Expires == null))
                    redirect = url.Redirect;
                else
                    redirect = error404;
            }
            return Redirect(redirect);
        }
        [Authorize]
        public ActionResult List()
        {

            List<Url> urls;
            if (User != null)
                user = _usersRepo.GetById(User.Identity.GetUserId());

            if (user.UserType == UserTypes.Administrator)
                urls = _repo.Urls;
            else urls = _repo.GetByUserId(user.Id);

            return View(urls);
        }

        //
        // GET: /Forwards/Details/5
        [Authorize]

        public ActionResult Details(int id)
        {
            if (User != null)
                user = _usersRepo.GetById(User.Identity.GetUserId());

            if (id == 0)
                Redirect("/Home/Index");
            Url url = _repo.GetById(id);
            return View(url);
        }

        //
        // GET: /Forwards/Create
        [Authorize]

        public ActionResult Create()
        {
            if (User != null)
                user = _usersRepo.GetById(User.Identity.GetUserId());

            Url url = new Url();
            string random = Helpers.GenerateRandomgUrl();
            while (_repo.Exists(random))
            {
                random = Helpers.GenerateRandomgUrl();
            }
            ViewBag.RandomUrl = random;
            return View(url);
        }

        [HttpGet]
        public string Available(string Src)
        {
            bool exists = _repo.Exists(Src);
            return new JavaScriptSerializer().Serialize(!exists);
        }
        //
        // POST: /Forwards/Create

        [Authorize]
        [HttpPost]
        public ActionResult Create(string Redirect, string Src, DateTime? Expires)
        {
            try
            {
                // TODO: Add insert logic here
                if (User != null)
                    user = _usersRepo.GetById(User.Identity.GetUserId());

                Url newUrl = new Url
                {
                    Redirect = Redirect,
                    Src = Src,
                    CreatedOn = DateTime.Now,
                    Expires = Expires,
                    UserId = user.Id,
                    Username = _usersRepo.GetUsername(user.Id)
                };

                if (_repo.needLastId)
                    newUrl.Id = _repo.LastId + 1;

                _repo.Add(newUrl);
                TempData["Success"] = "Short Url has been created";
                return RedirectToAction("List");
            }
            catch
            {
                TempData["Error"] = "There was an error saving your new Url";
                return View("List");
            }
        }

        //
        // GET: /Forwards/Edit/5
        [Authorize]

        public ActionResult Edit(int id)
        {
            if (User != null)
                user = _usersRepo.GetById(User.Identity.GetUserId());

            Url editUrl = _repo.GetById(id);
            return View(editUrl);
        }

        //
        // POST: /Forwards/Edit/5
        [Authorize]
        [HttpPost]
        public ActionResult Edit(int Id, string Redirect, string Src, DateTime? Expires = null)
        {
            try
            {
                // TODO: Add update logic here
                if (User != null)
                    user = _usersRepo.GetById(User.Identity.GetUserId());

                Url editUrl = _repo.GetById(Id);
                editUrl.Redirect = Redirect;
                editUrl.Src = Src;
                editUrl.UserId = user.Id;
                editUrl.Expires = Expires;
                editUrl.Username = _usersRepo.GetUsername(user.Id);

                _repo.Update(editUrl);
                TempData["Success"] = "Short Url has been updated";
                return RedirectToAction("List");
            }
            catch
            {
                TempData["Error"] = "There was an error saving your Url";
                return View();
            }
        }

        //
        // GET: /Forwards/Delete/5
        [Authorize]
        public ActionResult Delete(int id)
        {
            if (User != null)
                user = _usersRepo.GetById(User.Identity.GetUserId());
            Url url = _repo.GetById(id);
            return View(url);
        }

        [Authorize]
        [HttpPost]
        public ActionResult Delete(int id, bool confirm)
        {
            try
            {
                if (User != null)
                    user = _usersRepo.GetById(User.Identity.GetUserId());

                _repo.Remove(id);
                TempData["Success"] = "Short Url has been deleted";
                return RedirectToAction("List");

            }
            catch
            {
                TempData["Error"] = "There was an error deleting your Url";
                Url url = _repo.GetById(id);
                return View(url);
            }
        }

    }
}

RouteConfig.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;

namespace Shorten_Urls
{
    public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                name: "Forward",
                url: "{src}",
                defaults: new { controller = "Forwards", action = "SendToSrc", src = "" }
                );

            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );
        }
    }
}

Ao final, configura-se o

web.config

com as seguintes chaves:

 <appsettings>
    <add key="ForwardsFile" value="~/App_Data/forwards.xml"></add>
    <add key="LenghtOfRandomString" value="8"></add>
    <add key="WebsiteName" value="Puulga"></add>
    <add key="WebsiteUrl" value="http://puul.ga/"></add>
    <add key="Website" value="true"></add>
    <!--email provider section-->
    <add key="siteadmin" value="email@puul.ga"></add>
    <add key="email-subject" value="Email from Puul.ga"></add>
    <add key="email-from" value="email@puul.ga"></add>
    <add key="email-from-name" value="Puul.ga"></add>
    <add key="email-require-auth" value="false"></add>
    <add key="email-username" value="puul.ga"></add>
    <add key="email-password" value="password"></add>
    <add key="email-port" value="3535"></add>
    <add key="useSSL" value="false"></add>
    <add key="email-server" value="localhost"></add>
    <add key="email-html-share" value="~/Email Templates/share.html"></add>
    <add key="email-html-default" value="~/Email Templates/puulga.html"></add>
    <add key="email-html-forgotten" value="~/Email Templates/puulga.html"></add>
    <add key="email-html-confirmation" value="~/Email Templates/puulga.html"></add>
    <add key="email-html-welcome" value="~/Email Templates/puulga.html"></add>
    <!--Database options. possible values: Xml, Sql-->
    <add key="DbProvider" value="Sql"></add>
  </appsettings>

Basicamente, esses são os elementos mais importantes para o funcionamento do projeto. Todo o código fonte está disponível no Github em código aberto.

Visite o site para ver como funciona.