using System.ComponentModel.DataAnnotations.Schema;

namespace BlazorServer.Entities
{
    public class HotelRoomImage
    {
        public int Id { get; set; }

        public string RoomImageUrl { get; set; }

        [ForeignKey("RoomId")]
        public virtual HotelRoom HotelRoom { get; set; }
        public int RoomId { get; set; }
    }
}

namespace BlazorServer.Entities
{
    public class HotelRoom
    {
        // ...
        public virtual ICollection<HotelRoomImage> HotelRoomImages { get; set; }
    }
}

namespace BlazorServer.DataAccess
{
    public class ApplicationDbContext : DbContext
    {
        public DbSet<HotelRoomImage> HotelRoomImages { get; set; }

        // ...
    }
}

dotnet tool update --global dotnet-ef --version 5.0.3
dotnet build
dotnet ef migrations --startup-project ../BlazorServer.App/ add Init --context ApplicationDbContext
dotnet ef --startup-project ../BlazorServer.App/ database update --context ApplicationDbContext

namespace BlazorServer.Models
{
    public class HotelRoomImageDTO
    {
        public int Id { get; set; }

        public int RoomId { get; set; }

        public string RoomImageUrl { get; set; }
    }
}

using AutoMapper;
using BlazorServer.Entities;

namespace BlazorServer.Models.Mappings
{
    public class MappingProfile : Profile
    {
        public MappingProfile()
        {
            // ...
            CreateMap<HotelRoomImageDTO, HotelRoomImage>().ReverseMap(); // two-way mapping
        }
    }
}

namespace BlazorServer.Services
{
    public interface IHotelRoomImageService
    {
        Task<int> CreateHotelRoomImageAsync(HotelRoomImageDTO imageDTO);

        Task<int> DeleteHotelRoomImageByImageIdAsync(int imageId);

        Task<int> DeleteHotelRoomImageByRoomIdAsync(int roomId);

        Task<List<HotelRoomImageDTO>> GetHotelRoomImagesAsync(int roomId);
    }
}

namespace BlazorServer.Services
{
    public class HotelRoomImageService : IHotelRoomImageService
    {
        private readonly ApplicationDbContext _dbContext;
        private readonly IMapper _mapper;
        private readonly IConfigurationProvider _mapperConfiguration;

        public HotelRoomImageService(ApplicationDbContext dbContext, IMapper mapper)
        {
            _dbContext = dbContext ?? throw new ArgumentNullException(nameof(dbContext));
            _mapper = mapper ?? throw new ArgumentNullException(nameof(mapper));
            _mapperConfiguration = mapper.ConfigurationProvider;
        }

        public async Task<int> CreateHotelRoomImageAsync(HotelRoomImageDTO imageDTO)
        {
            var image = _mapper.Map<HotelRoomImage>(imageDTO);
            await _dbContext.HotelRoomImages.AddAsync(image);
            return await _dbContext.SaveChangesAsync();
        }

        public async Task<int> DeleteHotelRoomImageByImageIdAsync(int imageId)
        {
            var image = await _dbContext.HotelRoomImages.FindAsync(imageId);
            _dbContext.HotelRoomImages.Remove(image);
            return await _dbContext.SaveChangesAsync();
        }

        public async Task<int> DeleteHotelRoomImageByRoomIdAsync(int roomId)
        {
            var imageList = await _dbContext.HotelRoomImages.Where(x => x.RoomId == roomId).ToListAsync();
            _dbContext.HotelRoomImages.RemoveRange(imageList);
            return await _dbContext.SaveChangesAsync();
        }

        public Task<List<HotelRoomImageDTO>> GetHotelRoomImagesAsync(int roomId)
        {
            return _dbContext.HotelRoomImages
                            .Where(x => x.RoomId == roomId)
                            .ProjectTo<HotelRoomImageDTO>(_mapperConfiguration)
                            .ToListAsync();
        }
    }
}

namespace BlazorServer.App
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddScoped<IHotelRoomImageService, HotelRoomImageService>();
            // ...

using Microsoft.AspNetCore.Components.Forms;
using System.Threading.Tasks;

namespace BlazorServer.Services
{
    public interface IFileUploadService
    {
        void DeleteFile(string fileName, string webRootPath, string uploadFolder);
        Task<string> UploadFileAsync(IBrowserFile inputFile, string webRootPath, string uploadFolder);
    }
}

using Microsoft.AspNetCore.Components.Forms;
using System;
using System.IO;
using System.Threading.Tasks;

namespace BlazorServer.Services
{
    public class FileUploadService : IFileUploadService
    {
        private const int MaxBufferSize = 0x10000;

        public void DeleteFile(string fileName, string webRootPath, string uploadFolder)
        {
            var path = Path.Combine(webRootPath, uploadFolder, fileName);
            if (File.Exists(path))
            {
                File.Delete(path);
            }
        }

        public async Task<string> UploadFileAsync(IBrowserFile inputFile, string webRootPath, string uploadFolder)
        {
            createUploadDir(webRootPath, uploadFolder);
            var (fileName, imageFilePath) = getOutputFileInfo(inputFile, webRootPath, uploadFolder);

            using (var outputFileStream = new FileStream(
                        imageFilePath, FileMode.Create, FileAccess.Write,
                        FileShare.None, MaxBufferSize, useAsync: true))
            {
                using var inputStream = inputFile.OpenReadStream();
                await inputStream.CopyToAsync(outputFileStream);
            }

            return $"{uploadFolder}/{fileName}";
        }

        private static (string FileName, string FilePath) getOutputFileInfo(
                    IBrowserFile inputFile, string webRootPath, string uploadFolder)
        {
            var fileName = Path.GetFileName(inputFile.Name);
            var imageFilePath = Path.Combine(webRootPath, uploadFolder, fileName);
            if (File.Exists(imageFilePath))
            {
                var fileNameWithoutExtension = Path.GetFileNameWithoutExtension(fileName);
                var fileExtension = Path.GetExtension(fileName);
                fileName = $"{fileNameWithoutExtension}-{Guid.NewGuid()}{fileExtension}";
                imageFilePath = Path.Combine(webRootPath, uploadFolder, fileName);
            }
            return (fileName, imageFilePath);
        }

        private static void createUploadDir(string webRootPath, string uploadFolder)
        {
            var folderDirectory = Path.Combine(webRootPath, uploadFolder);
            if (!Directory.Exists(folderDirectory))
            {
                Directory.CreateDirectory(folderDirectory);
            }
        }
    }
}

<Project Sdk="Microsoft.NET.Sdk">
  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Components.Web" Version="5.0.3" />
  </ItemGroup>
</Project>

namespace BlazorServer.App
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddScoped<IFileUploadService, FileUploadService>();
            // ...

import RegisterForm from "./components/registerForm";

<Route path="/register" component={RegisterForm} />

<NavLink className="nav-item nav-link" to="/register">
   Register
</NavLink>

import Joi from "@hapi/joi";
import React from "react";

import Form from "./common/form";

class RegisterForm extends Form {
  state = {
    data: { username: "", password: "", name: "" },
    errors: {}
  };

  schema = {
    username: Joi.string()
      .required()
      .email({ minDomainSegments: 2, tlds: { allow: ["com", "net"] } })
      .label("Username"),
    password: Joi.string()
      .required()
      .min(5)
      .label("Password"),
    name: Joi.string()
      .required()
      .label("Name")
  };

  doSubmit = () => {
    // Call the server
    console.log("Submitted");
  };

  render() {
    return (
      <div>
        <h1>Register</h1>
        <form onSubmit={this.handleSubmit}>
          {this.renderInput("username", "Username")}
          {this.renderInput("password", "Password", "password")}
          {this.renderInput("name", "Name")}
          {this.renderButton("Register")}
        </form>
      </div>
    );
  }
}

export default RegisterForm;

import { Link } from "react-router-dom";
// ...


<div className="col">
  <Link
    to="/movies/new"
    className="btn btn-primary"
    style={{ marginBottom: 20 }}
  >
    New Movie
  </Link>
  <p>Showing {totalCount} movies in the database.</p>

import Joi from "@hapi/joi";
import React from "react";

import { getGenres } from "../services/fakeGenreService";
import { getMovie, saveMovie } from "../services/fakeMovieService";
import Form from "./common/form";

class MovieForm extends Form {
  state = {
    data: {
      title: "",
      genreId: "",
      numberInStock: "",
      dailyRentalRate: ""
    },
    genres: [],
    errors: {}
  };

  schema = {
    _id: Joi.string(),
    title: Joi.string()
      .required()
      .label("Title"),
    genreId: Joi.string()
      .required()
      .label("Genre"),
    numberInStock: Joi.number()
      .required()
      .min(0)
      .max(100)
      .label("Number in Stock"),
    dailyRentalRate: Joi.number()
      .required()
      .min(0)
      .max(10)
      .label("Daily Rental Rate")
  };

  componentDidMount() {
    const genres = getGenres();
    this.setState({ genres });

    const movieId = this.props.match.params.id;
    if (movieId === "new") return;

    const movie = getMovie(movieId);
    if (!movie) return this.props.history.replace("/not-found");

    this.setState({ data: this.mapToViewModel(movie) });
  }

  mapToViewModel(movie) {
    return {
      _id: movie._id,
      title: movie.title,
      genreId: movie.genre._id,
      numberInStock: movie.numberInStock,
      dailyRentalRate: movie.dailyRentalRate
    };
  }

  doSubmit = () => {
    saveMovie(this.state.data);

    this.props.history.push("/movies");
  };

  render() {
    return (
      <div>
        <h1>Movie Form</h1>
        <form onSubmit={this.handleSubmit}>
          {this.renderInput("title", "Title")}
          {this.renderSelect("genreId", "Genre", this.state.genres)}
          {this.renderInput("numberInStock", "Number in Stock", "number")}
          {this.renderInput("dailyRentalRate", "Rate")}
          {this.renderButton("Save")}
        </form>
      </div>
    );
  }

import React from "react";

const Select = ({ name, label, options, error, ...rest }) => {
  return (
    <div className="form-group">
      <label htmlFor={name}>{label}</label>
      <select name={name} id={name} {...rest} className="form-control">
        <option value="" />
        {options.map(option => (
          <option key={option._id} value={option._id}>
            {option.name}
          </option>
        ))}
      </select>
      {error && <div className="alert alert-danger">{error}</div>}
    </div>
  );
};

export default Select;

import Select from "./select";
// ...

class Form extends Component {

  // ...

  renderSelect(name, label, options) {
    const { data, errors } = this.state;

    return (
      <Select
        name={name}
        value={data[name]}
        label={label}
        options={options}
        onChange={this.handleChange}
        error={errors[name]}
      />
    );
  }
}

import React from "react";

const SearchBox = ({ value, onChange }) => {
  return (
    <input
      type="text"
      name="query"
      className="form-control my-3"
      placeholder="Search..."
      value={value}
      onChange={e => onChange(e.currentTarget.value)}
    />
  );
};

export default SearchBox;

<p>Showing {totalCount} movies in the database.</p>
<SearchBox value={searchQuery} onChange={this.handleSearch} />

import SearchBox from "./searchBox";
//...

class Movies extends Component {
  state = {
    //...
    selectedGenre: {},
    searchQuery: ""
  };


  handleSearch = query => {
    this.setState({ searchQuery: query, selectedGenre: null, currentPage: 1 });
  };

  handleGenreSelect = genre => {
    console.log("handleGenreSelect", genre);
    this.setState({ selectedGenre: genre, searchQuery: "", currentPage: 1 });
  };

  getPagedData() {
    const {
      pageSize,
      currentPage,
      selectedGenre,
      movies: allMovies,
      sortColumn,
      searchQuery
    } = this.state;

    let filteredMovies = allMovies;
    if (searchQuery) {
      filteredMovies = allMovies.filter(m =>
        m.title.toLowerCase().startsWith(searchQuery.toLowerCase())
      );
    } else if (selectedGenre && selectedGenre._id) {
      filteredMovies = allMovies.filter(m => m.genre._id === selectedGenre._id);
    }

<component type="typeof(App)" render-mode="ServerPrerendered" />

<body>
    <component type="typeof(App)" render-mode="WebAssemblyPrerendered" /> 
    <persist-component-state />
</body>

@page "/"

@implements IDisposable
@inject PersistentComponentState applicationState
@inject IUserRepository userRepository

@foreach(var user in users)
{
    <ShowUserInformation user="@item"></ShowUserInformation>
}

@code {
    private const string cachingKey = "something_unique";
    private List<User> users = new();
    private PersistingComponentStateSubscription persistingSubscription;
    
    protected override async Task OnInitializedAsync()
    {
        persistingSubscription = applicationState.RegisterOnPersisting(PersistData);

        if (applicationState.TryTakeFromJson<List<User>>(cachingKey, out var restored))
        {
            users = restored;
        }
        else 
        {
            users = await userRepository.GetAllUsers();
        }
    }

    public void Dispose()
    {
        persistingSubscription.Dispose();
    }

    private Task PersistData()
    {
        applicationState.PersistAsJson(cachingKey, users);
        return Task.CompletedTask;
    }

}

<!--Blazor-Server-Component-State:CfDJXyz->
<!--Blazor-WebAssembly-Component-State:eyJVc2Xyz->

@rendermode renderMode

@code 
{
    private static IComponentRenderMode renderMode = new InteractiveWebAssemblyRenderMode(prerender: false);
}

@implements IDisposable

@inject IProductStore ProductStore
@inject PersistentComponentState PersistentState

<h3>Related products</h3>

@if (_relatedProducts == null)
{
    <p>Loading...</p>
}
else
{
    <div class="mt-3">
        @foreach (var item in _relatedProducts)
        {
            <a href="/ProductDetails/@item.Id">
                <div class="col-sm">
                    <h5 class="mt-0">@item.Title (@item.Price)</h5>
                </div>
            </a>
        }
    </div>
}

@code{

    private const string StateCachingKey = "products";
    private IList<Product>? _relatedProducts;
    private PersistingComponentStateSubscription _persistingSubscription;

    [Parameter]
    public int ProductId { get; set; }

    protected override async Task OnInitializedAsync()
    {
        _persistingSubscription = PersistentState.RegisterOnPersisting(OnPersistingAsync, RenderMode.InteractiveWebAssembly);

        if (PersistentState.TryTakeFromJson<IList<Product>>(StateCachingKey, out var restored))
        {
            _relatedProducts = restored;
        }
        else
        {
            await Task.Delay(500); // Simulates asynchronous loading
            _relatedProducts = await ProductStore.GetRelatedProducts(ProductId);
        }
    }

    private Task OnPersistingAsync()
    {
        PersistentState.PersistAsJson(StateCachingKey, _relatedProducts);
        return Task.CompletedTask;
    }

    public void Dispose()
    {
        _persistingSubscription.Dispose();
    }

}

type  name  initializer ;

int sum(0);   //  یا  int sum=0;

char ch(65);  //  ch is A

float  pi(3.14);  //  یا  float  pi = 3.14;

flot   f(0.0) ;   //  خطای نام نوع گرفته می‌شود
auto  f(0.0);   //  نیازی به وارد نمودن نوع تایپ نیستیم

map<string, string> address_book;
address_book[ "Alex" ] = "example@yahoo.com";

map<string, string>::iterator itr = address_book.begin();

auto itr = address_book.begin();

import React from 'react'
import { useLocalStore, useObserver } from 'mobx-react' // 6.x

export const SmartTodo = () => {
  const todo = useLocalStore(() => ({
    title: 'Click to toggle',
    done: false,
    toggle() {
      todo.done = !todo.done
    },
    get emoji() {
      return todo.done ? '😜' : '🏃'
    },
  }))

  return useObserver(() => (
    <h3 onClick={todo.toggle}>
      {todo.title} {todo.emoji}
    </h3>
  ))
}

export function createStore() {
  return {
   // ...
  }
}

import React from 'react';
import { createStore } from './createStore';
import { useLocalStore } from 'mobx-react'; // 6.x or mobx-react-lite@1.4.0

const storeContext = React.createContext(null);

export const StoreProvider = ({ children }) => {
  const store = useLocalStore(createStore);
  return <storeContext.Provider value={store}>{children}</storeContext.Provider>;
}

export const useStore = () => {
  const store = React.useContext(storeContext);
  if (!store) {
    throw new Error('useStore must be used within a StoreProvider.');
  }
  return store
}

export default function App() {
  return (
    <StoreProvider>
      <main>
        <Component1 />
        <Component2 />
        <Component3 />
      </main>
    </StoreProvider>
  );
}

const store = useStore();

export const storesContext = React.createContext({
  counterStore: new CounterStore(),
  themeStore: new ThemeStore(),
});

export const useStores = () => React.useContext(storesContext);

const { counterStore } = useStores();

const {
    counterStore: { activeUserName },
} = useStores();

const { counterStore } = useStores();

import React from 'react'
import { autorun } from 'mobx'

function useDocumentTitle(store) {
  React.useEffect(
    () =>
      autorun(() => {
        document.title = `${store.title} - ${store.sectionName}`
      }),
    [], // note empty dependencies
  )
}

import { configure } from "mobx";
configure({ enforceActions: true });

@action
loadWeather = city => {
  fetch(
    `https://abnormal-weather-api.herokuapp.com/cities/search?city=${city}`
  )
    .then(response => response.json())
    .then(data => {
      this.weatherData = data;
    });
};

@action setWeather = data => {
    this.weatherData = data;
};

  loadWeatherInline = city => {
    fetch(`http://jsonplaceholder.typicode.com/comments/${city}`)
      .then(response => response.json())
      .then(data => {
        runInAction(() => (this.weatherData = data));
      });
  };

  loadWeatherAsync = async city => {
    const response = await fetch(
      `http://jsonplaceholder.typicode.com/comments/${city}`
    );
    const data = await response.json();
    runInAction(() => {
      this.weatherData = data;
    });
  };

public class BasicMath : IBinaryOperations<int>
{
   public int Add(int arg1, int arg2)
   { return arg1 + arg2; }
 
   public int Subtract(int arg1, int arg2)
   { return arg1 - arg2; }
 
   public int Multiply(int arg1, int arg2)
   { return arg1 * arg2; }
 
   public int Divide(int arg1, int arg2)
   { return arg1 / arg2; }
}

static void Main(string[] args)
{
   Console.WriteLine("***** Generic Interfaces *****\n");
   BasicMath m = new BasicMath();
   Console.WriteLine("1 + 1 = {0}", m.Add(1, 1));
   Console.ReadLine();
}

public class BasicMath : IBinaryOperations<double>
{
   public double Add(double arg1, double arg2)
   { return arg1 + arg2; }
   ...
}