How to create an Angular 4 app with Visual Studio 2017 

ASP.NET 5 (and ASP.NET MVC 6) includes a new routing framework rewritten from the ground up. In this blog post, I’ve provided a deep dive into how this new framework works. 

Security Advisory Notices

CVE-2019-1077 Visual Studio Extension Auto Update Vulnerability

An elevation of privilege vulnerability exists when the Visual Studio Extension auto-update process improperly performs certain file operations. An attacker who successfully exploited this vulnerability could delete files in arbitrary locations. To exploit this vulnerability, an attacker would require unprivileged access to a vulnerable system. The security update addresses the vulnerability by securing locations the Visual Studio Extension auto-update performs file operations in.

CVE-2019-1075 ASP.NET Core Spoofing Vulnerability

A spoofing vulnerability exists in ASP.NET Core that could lead to an open redirect. An attacker who successfully exploited the vulnerability could redirect a targeted user to a malicious website. To exploit the vulnerability, an attacker could send a link that has a specially crafted URL and convince the user to click the link.

The security update addresses the vulnerability by correcting how ASP.NET Core parses URLs. Details can be found in the .NET Core release notes.

CVE-2019-1113 WorkflowDesigner XOML deserialization allows code execution

A XOML file referencing certain types could cause random code to be executed when the XOML file is opened in Visual Studio. There is now a restriction on what types are allowed to be used in XOML files. If a XOML file containing one of the newly unauthorized types is opened, a message is displayed explaining that the type is unauthorized.

For further information, please refer to https://support.microsoft.com/en-us/help/4512190/remote-code-execution-vulnerability-if-types-are-specified-in-xoml.

In this video, you will get to experience bringing SQL and Spark together as a unified data platform running on Kubernetes and learn how:

• Data virtualization integrates data from disparate sources, locations and formats, without replicating or moving the data, to create a single "virtual" data layer

• Data Lake - SQL 2019 provides SQL and Spark query capabilities over a scalable storage, across relational and big data

• Data Mart provides an ability to scale out storage for super-fast performance over big data or data from other external sources 

class LoginForm extends Component {
  state = {
    account: { username: "", password: "" },
    errors: {
      username: "Username is required"
    }
  };

  validate = () => {
    return { username: "Username is required." };
  };

  handleSubmit = e => {
    e.preventDefault();

    const errors = this.validate();
    console.log("Validation errors", errors);
    this.setState({ errors });
    if (errors) {
      return;
    }

    // call the server
    console.log("Submitted!");
  };

  validate = () => {
    const { account } = this.state;

    const errors = {};
    if (account.username.trim() === "") {
      errors.username = "Username is required.";
    }

    if (account.password.trim() === "") {
      errors.password = "Password is required.";
    }

    return Object.keys(errors).length === 0 ? null : errors;
  };

import React from "react";

const Input = ({ name, label, value, error, onChange }) => {
  return (
    <div className="form-group">
      <label htmlFor={name}>{label}</label>
      <input
        value={value}
        onChange={onChange}
        id={name}
        name={name}
        type="text"
        className="form-control"
      />
      {error && <div className="alert alert-danger">{error}</div>}
    </div>
  );
};

export default Input;

  render() {
    const { account, errors } = this.state;
    return (
      <form onSubmit={this.handleSubmit}>
        <Input
          name="username"
          label="Username"
          value={account.username}
          onChange={this.handleChange}
          error={errors.username}
        />
        <Input
          name="password"
          label="Password"
          value={account.password}
          onChange={this.handleChange}
          error={errors.password}
        />
        <button className="btn btn-primary">Login</button>
      </form>
    );
  }

loginForm.jsx:55 Uncaught TypeError: Cannot read property 'username' of null
at LoginForm.render (loginForm.jsx:55)

this.setState({ errors: errors || {} });

  handleChange = ({ currentTarget: input }) => {
    const errors = { ...this.state.errors }; //cloning an object
    const errorMessage = this.validateProperty(input);
    if (errorMessage) {
      errors[input.name] = errorMessage;
    } else {
      delete errors[input.name];
    }

    const account = { ...this.state.account }; //cloning an object
    account[input.name] = input.value;

    this.setState({ account, errors });
  };

  validateProperty = ({ name, value }) => {
    if (name === "username") {
      if (value.trim() === "") {
        return "Username is required.";
      }
      // ...
    }

    if (name === "password") {
      if (value.trim() === "") {
        return "Password is required.";
      }
      // ...
    }
  };

const Joi = require('@hapi/joi');
const schema = Joi.object({
    username: Joi.string().alphanum().min(3).max(30).required(),
    password: Joi.string().pattern(/^[a-zA-Z0-9]{3,30}$/),
    email: Joi.string().email({ minDomainSegments: 2, tlds: { allow: ['com', 'net'] } })
});
schema.validate({ username: 'abc', birth_year: 1994 });

> npm install @hapi/joi --save
> npm i --save-dev @types/hapi__joi

import Joi from "@hapi/joi";

  schema = {
    username: Joi.string()
      .required()
      .label("Username"),
    password: Joi.string()
      .required()
      .label("Password")
  };

  validate = () => {
    const { account } = this.state;
    const validationResult = Joi.object(this.schema).validate(account, {
      abortEarly: false
    });
    console.log("validationResult", validationResult);

  validate = () => {
    const { account } = this.state;
    const validationResult = Joi.object(this.schema).validate(account, {
      abortEarly: false
    });
    console.log("validationResult", validationResult);

    if (!validationResult.error) {
      return null;
    }

    const errors = {};
    for (let item of validationResult.error.details) {
      errors[item.path[0]] = item.message;
    }
    return errors;
  };

  validateProperty = ({ name, value }) => {
    const userInputObject = { [name]: value };
    const propertySchema = Joi.object({ [name]: this.schema[name] });
    const { error } = propertySchema.validate(userInputObject, {
      abortEarly: true
    });
    return error ? error.details[0].message : null;
  };

 <button disabled={this.validate()} className="btn btn-primary">
 Login
</button>

• Microsoft will change how it reports financially.
• Microsoft will become a “consumer-focused enterprise company.”
• Windows will converge into a single code base capable of running on any platform.
• Application development will converge into allowing developers to maintain a single code base for an app that will run on any device capable of running Windows.
• Release frequency will dramatically increase.
• The “modern” user interface is here to stay.  

At The Bit, we understand how overwhelming  it can be to navigate through all the different tutorials online and try to teach yourself programming skills alone.

That’s why we’ve created The Bit — we’ll match you to a peer with similar skills and interests to take the tutorial of your choosing.

Find a tutorial you want to take below? Upload it to our platform to get the support and accountability you need to start building cool shit. 

using System.ComponentModel.DataAnnotations;

namespace BlazorAsyncValidation.Shared;

public class UserDto
{
    [Required] public string Name { set; get; } = default!;
}

using BlazorAsyncValidation.Shared;
using Microsoft.AspNetCore.Mvc;

namespace BlazorAsyncValidation.Server.Controllers;

[ApiController, Route("api/[controller]/[action]")]
public class RegisterController : ControllerBase
{
    [HttpPost]
    public IActionResult IsUserNameUnique([FromBody] UserDto userModel)
    {
        if (string.Equals(userModel?.Name, "Vahid", StringComparison.OrdinalIgnoreCase))
        {
            return Ok(false);
        }

        return Ok(true);
    }
}

@page "/"

<PageTitle>Index</PageTitle>

<h2>Register</h2>

<EditForm EditContext="@EditContext" OnValidSubmit="DoSubmitAsync">
    <DataAnnotationsValidator/>
    <div class="row mb-2">
        <label class="col-form-label col-lg-2">Name:</label>
        <div class="col-lg-10">
            <InputText @bind-Value="Model.Name" class="form-control"/>
            <ValidationMessage For="@(() => Model.Name)"/>
        </div>
    </div>

    <button class="btn btn-secondary" type="submit">Submit</button>
</EditForm>

public partial class Index
{
    private const string UserValidationUrl = "/api/Register/IsUserNameUnique";

    private ValidationMessageStore? _messageStore;
    [Inject] private HttpClient HttpClient { set; get; } = default!;
    private EditContext? EditContext { set; get; }

    private UserDto Model { get; } = new();

    protected override void OnInitialized()
    {
        EditContext = new EditContext(Model);
        _messageStore = new ValidationMessageStore(EditContext);
        EditContext.OnFieldChanged += (sender, eventArgs) =>
        {
            var fieldIdentifier = eventArgs.FieldIdentifier;
            _messageStore?.Clear(fieldIdentifier);
            _ = InvokeAsync(async () =>
            {
                var errors = await OnValidateFieldAsync(fieldIdentifier.FieldName);
                if (errors?.Any() != true)
                {
                    return;
                }

                foreach (var error in errors)
                {
                    _messageStore?.Add(fieldIdentifier, error);
                }

                EditContext.NotifyValidationStateChanged();
            });
            StateHasChanged();
        };
        EditContext.OnValidationStateChanged += (sender, eventArgs) => StateHasChanged();
        EditContext.OnValidationRequested += (sender, eventArgs) => _messageStore?.Clear();
    }

    private async Task<IList<string>?> OnValidateFieldAsync(string fieldName)
    {
        switch (fieldName)
        {
            case nameof(UserDto.Name):
                var response = await HttpClient.PostAsJsonAsync(
                    UserValidationUrl,
                    new UserDto { Name = Model.Name });
                var responseContent = await response.Content.ReadAsStringAsync();
                if (string.Equals(responseContent, "false", StringComparison.OrdinalIgnoreCase))
                {
                    return new List<string>
                    {
                        $"`{Model.Name}` is in use. Please choose another name."
                    };
                }

                // TIP: It's better to use the `DntDebounceInputText` component for this case to reduce the network round-trips.

                break;
        }

        return null;
    }

Can database-style sharding improve the performance of a multi-threaded C# application? This tutorial talks about the performance bottlenecks in sophisticated C# concurrency operations and how sharding can solve these issues.  

As anyone in the .NET community who hasn't been living under a rock will know, there's a lot of exciting things happening with .NET at the moment with the announcement of the open source, cross platform, .NET Core. However, partly due to the very open nature of its evolution, there's been a whole host of names associated with its development - vNext, ASP.NET 5, ASP.NET Core, .NET generations etc.

In this post I'm going to try and clarify some of the naming and terminology surrounding the evolution of the .NET framework. I'll discuss some of the challenges the latest iteration is attempting to deal with and how the latest developments aim to address these.

This is really for those that have seen some of the big announcements but aren't sure about the intricacies of this new framework and how it relates to the existing ecosystem, which was my situation before I really started digging into it all properly!

Hopefully by the end of this article you'll have a clearer grasp of the latest in .NET!