Setup Mkdocs (#7)

* Compile docs with Mkdocs

* Add info about project

docs/dotnet/asp.net/mvc.md

@@ -0,0 +1,259 @@
+# ASP.NET (Core) MVC Web App
+
+## Project Structure
+
+```txt
+Project
+|-Properties
+| |- launchSettings.json
+|
+|-wwwroot  --> location of static files
+| |-css
+| | |- site.css
+| |
+| |-js
+| | |- site.js
+| |
+| |-lib
+| | |- bootstrap
+| | |- jquery
+| | |- ...
+| |
+| |- favicon.ico
+|
+|-Model
+| |-ErrorViewModel.cs
+| |- Index.cs
+| |-...
+|
+|-Views
+| |-Home
+| | |- Index.cshtml
+| |
+| |-Shared
+| | |- _Layout.cshtml  --> reusable default page layout
+| | |- _ValidationScriptsPartial  --> jquery validation script imports
+| |
+| |- _ViewImports.cshtml  --> shared imports and tag helpers for all views
+| |- _ViewStart.cshtml  --> shared values for all views
+| |- ...
+|
+|-Controllers
+| |-HomeController.cs
+|
+|- appsettings.json
+|- Program.cs  --> App entry-point
+|- Startup.cs  --> App config
+```
+
+**Note**: `_` prefix indicates page to be imported.
+
+## Controllers
+
+```cs
+using Microsoft.AspNetCore.Mvc;
+using App.Models;
+using System.Collections.Generic;
+
+namespace App.Controllers
+{
+    public class CategoryController : Controller
+    {
+        private readonly AppDbContext _db;
+
+        // get db context through dependency injection
+        public CategoryController(AppDbContext db)
+        {
+            _db = db;
+        }
+
+        // GET /Controller/Index
+        public IActionResult Index()
+        {
+            IEnumerable<Entity> entities = _db.Entities;
+            return View(Entities);  // pass data to the @model
+        }
+
+        // GET /Controller/Create
+        public IActionResult Create()
+        {
+            return View();
+        }
+
+        // POST /Controller/Create
+        [HttpPost]
+        [ValidateAntiForgeryToken]
+        public IActionResult Create(Entity entity)  // receive data from the @model
+        {
+            _db.Entities.Add(entity);
+            _db.SaveChanges();
+            return RedirectToAction("Index");  // redirection
+        }
+
+        // GET - /Controller/Edit
+        public IActionResult Edit(int? id)
+        {
+            if(id == null || id == 0)
+            {
+                return NotFound();
+            }
+
+            Entity entity = _db.Entities.Find(id);
+            if (entity == null)
+            {
+                return NotFound();
+            }
+
+            return View(entity);  // return populated form for updating
+        }
+
+        // POST /Controller/Edit
+        [HttpPost]
+        [ValidateAntiForgeryToken]
+        public IActionResult Edit(Entity entity)
+        {
+            if (ModelState.IsValid)  // all rules in model have been met
+            {
+                _db.Entities.Update(entity);
+                _db.SaveChanges();
+                return RedirectToAction("Index");
+            }
+
+            return View(entity);
+        }
+
+        // GET /controller/Delete
+        public IActionResult Delete(int? id)
+        {
+            if (id == null || id == 0)
+            {
+                return NotFound();
+            }
+
+            Entity entity = _db.Entities.Find(id);
+            if (entity == null)
+            {
+                return NotFound();
+            }
+
+            return View(entity);  // return populated form for confirmation
+        }
+
+        // POST /Controller/Delete
+        [HttpPost]
+        [ValidateAntiForgeryToken]
+        public IActionResult Delete(Entity entity)
+        {
+            if (ModelState.IsValid)  // all rules in model have been met
+            {
+                _db.Entities.Remove(entity);
+                _db.SaveChanges();
+                return RedirectToAction("Index");
+            }
+
+            return View(entity);
+        }
+    }
+}
+```
+
+## Data Validation
+
+### Model Annotations
+
+In `Entity.cs`:
+
+```cs
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+
+namespace App.Models
+{
+    public class Entity
+    {
+        [DisplayName("Integer Number")]
+        [Required]
+        [Range(1, int.MaxValue, ErrorMessage = "Error Message")]
+        public int IntProp { get; set; }
+    }
+}
+```
+
+### Tag Helpers & Client Side Validation
+
+In `View.cshtml`;
+
+```cs
+<form method="post" asp-action="Create">
+    <div asp-validation-summary="ModelOnly" class="text-danger"></div>
+
+    <div class="form-group row">
+        <div class="col-4">
+            <label asp-for="IntProp"></label>
+        </div>
+
+        <div class="col-8">
+            <input asp-for="IntProp" class="form-control"/>
+            <span asp-validation-for="IntProp" class="text-danger"></span>  // error message displayed here
+        </div>
+    </div>
+</form>
+
+// client side validation
+@section Scripts{ 
+    @{ <partial name="_ValidationScriptsPartial" /> }
+}
+```
+
+### Server Side Validation
+
+```cs
+using Microsoft.AspNetCore.Mvc;
+using App.Models;
+using System.Collections.Generic;
+
+namespace App.Controllers
+{
+    public class CategoryController : Controller
+    {
+        private readonly AppDbContext _db;
+
+        // get db context through dependency injection
+        public CategoryController(AppDbContext db)
+        {
+            _db = db;
+        }
+
+        // GET /Controller/Index
+        public IActionResult Index()
+        {
+            IEnumerable<Entity> entities = _db.Entities;
+            return View(Entities);  // pass data to the @model
+        }
+
+        // GET /Controller/Create
+        public IActionResult Create()
+        {
+            return View();
+        }
+
+        // POST /Controller/Create
+        [HttpPost]
+        [ValidateAntiForgeryToken]
+        public IActionResult Create(Entity entity)  // receive data from the @model
+        {
+            if (ModelState.IsValid)  // all rules in model have been met
+            {
+                _db.Entities.Add(entity);
+                _db.SaveChanges();
+                return RedirectToAction("Index");
+            }
+
+            return View(entity);   // return model and display error messages
+        }
+    }
+}
+```