Flunt C# (How It Works For Developers)

How to use Flunt in C#

1. Create a new C# console project.
2. Install the Flunt package from NuGet.
3. Import the namespace and inherit the class.
4. Add the validation to the data model.
5. Perform validation checks and display the result.

Understanding of Flunt C#

The versatile and lightweight .NET framework, Flunt, was created to facilitate the development of fluent validation and notification patterns in C# applications. Code becomes more legible and maintained when developers use Flunt to construct validation rules and business logic in a fluid and expressive way. With Flunt's extensive range of integrated validation techniques and extensions, developers can easily validate intricate data structures like objects and collections.

Moreover, Flunt is a useful tool for boosting the dependability and robustness of .NET library applications since it easily integrates with current codebases and frameworks. All in all, Flunt encourages a declarative approach to validation and error handling, enabling developers to write cleaner, more robust code.

Getting Started with Flunt C#

Flunt C# Example

You can use the following code Flunt as soon as it's installed. This is a simple example that shows you how to use Flunt to construct validation rules:

using System;
using Flunt.Validations;

public class Program
{
    static void Main(string[] args)
    {
        var person = new Person { Name = "Jack", Age = -25 };
        var contract = new PersonContract(person);

        // Perform validation checks
        if (contract.IsValid)
        {
            Console.WriteLine("Person is valid!");
        }
        else
        {
            Console.WriteLine("Validation failed:");
            foreach (var notification in contract.Notifications)
            {
                Console.WriteLine($"- {notification.Key}: {notification.Message}");
            }
        }
    }
}

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public class PersonContract : Contract<Person>
{
    public PersonContract(Person person)
    {
        // Ensure the correct format of the object
        Requires()
            .IsNotNull(person, nameof(person))
            .IsNotEmpty(person.Name, nameof(person.Name), "Name is required")
            .IsGreaterThan(person.Age, 0, nameof(person.Age), "Age must be a positive number");
    }
}

using System;
using Flunt.Validations;

public class Program
{
    static void Main(string[] args)
    {
        var person = new Person { Name = "Jack", Age = -25 };
        var contract = new PersonContract(person);

        // Perform validation checks
        if (contract.IsValid)
        {
            Console.WriteLine("Person is valid!");
        }
        else
        {
            Console.WriteLine("Validation failed:");
            foreach (var notification in contract.Notifications)
            {
                Console.WriteLine($"- {notification.Key}: {notification.Message}");
            }
        }
    }
}

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public class PersonContract : Contract<Person>
{
    public PersonContract(Person person)
    {
        // Ensure the correct format of the object
        Requires()
            .IsNotNull(person, nameof(person))
            .IsNotEmpty(person.Name, nameof(person.Name), "Name is required")
            .IsGreaterThan(person.Age, 0, nameof(person.Age), "Age must be a positive number");
    }
}

Person Class: Represents an entity with Name and Age properties.

PersonContract: This class derives from Flunt's fundamental concept of Contract<T>. Using the Requires method, the constructor takes a Person object and provides validation rules. Requires offers a chainable method for defining multiple validations. Validations are carried out by methods like IsNotNull, IsNotEmpty, IsGreaterThan. Each validation rule has an associated custom error message.

Validation: Similar to a FluentValidation example, this creates an instance of a PersonContract and a Person object. The validation results are shown by the contract's IsValid attribute. Notifications of success or failure, as well as specific error messages, are displayed based on the validation outcome.

Flunt Operations

For validation and notification handling in C# applications, Flunt offers many operations, such as:

Creating Validation Rules: To create validation rules for attributes like mandatory fields, data types, value ranges, maximum length, and minimum length, use the fluent interface.

Executing Validation: To guarantee data integrity and adherence to business logic, validate objects against predefined rules.

Managing Validation Mistakes: Note and record validation mistakes as alerts and respond to them politely by giving users error messages or recording errors for troubleshooting.

Custom Validation Logic: Use unique validation rules to extend Flunt in response to intricate validation circumstances or particular domain requirements.

Integration with Frameworks: To improve validation capabilities in current applications, Flunt may be seamlessly integrated with many well-known .NET frameworks and libraries, including Entity Framework, ASP.NET Core, and more.

Integrating Flunt with IronPDF

Developers can harness the strengths of both technologies to expedite business logic validation and document creation in C# applications by integrating Flunt with IronPDF. Applications can be made more dependable and user-friendly by developers by using IronPDF to create PDF documents after validating input data with Flunt.

Install IronPDF

• Launch the Visual Studio project.
• Select "Tools" > "NuGet Package Manager" > "Package Manager Console".
• Input this command into the Package Manager Console:

Install-Package IronPdf

• As an alternative, you can use the NuGet Package Manager for Solutions to install IronPDF and other necessary NuGet Packages.
• Click the "Install" button after exploring and choosing the IronPDF package from the search results. The installation and download will be handled by Visual Studio.

• Installing the IronPDF package and any dependencies needed for your project will be handled by NuGet.
• After installation, IronPDF is available for use in your project.

Implementing Logic

Let's create a basic C# application that uses IronPDF for PDF creation and Flunt for data validation. In this example, we will use Flunt to validate user input for a registration form, and IronPDF to create a PDF document with a summary of the user data that has been verified.

1. Person Class: A Person class with attributes for name and age is defined. We validate the Person data against predefined validation rules by using Flunt's fluent interface in the constructor.
2. Generate Pdf: A method called RenderHtmlAsPdf is defined, and it accepts a User object as input. This function renders the HTML text representing the user registration summary into a PDF document by using IronPDF's HtmlToPdf class.
3. Main Method: Using sample Person data, we build an instance of the User class in the Main method. Next, we use Flunt's IsValid attribute to determine whether the Person data is legitimate. To create the PDF document, we invoke the IronPdf method if the data is correct. If not, the validation problems are shown on the console.

We have developed a fast workflow for evaluating user input and generating PDF documents in a C# application by combining IronPDF for PDF generation with Flunt for data validation. This method ensures data integrity, generates professional-quality documents, and encourages the writing of clear, readable, and maintainable code. To read more about IronPDF's capabilities, refer to the documentation page. Below is the sample code snippet.

using IronPdf;
using System;
using System.Linq;
using System.Text;
using Flunt.Validations;

namespace ConsoleApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
            // StringBuilder for HTML content
            StringBuilder sb = new StringBuilder();
            var person = new Person { Name = "Jack", Age = -25 };
            var contract = new PersonContract(person);

            if (contract.IsValid)
            {
                Console.WriteLine("Person is valid!");
                sb.Append("<p>Person is valid!</p>");
            }
            else
            {
                sb.Append("<p>Validation failed: </p>");
                foreach (var notification in contract.Notifications)
                {
                    sb.Append($"- {notification.Key}: {notification.Message}<br>");
                }
            }

            var renderer = new HtmlToPdf();
            // Set HTML content for the page
            var pdfDocument = renderer.RenderHtmlAsPdf(sb.ToString());
            // Save the document
            pdfDocument.SaveAs("output.pdf");
            // Dispose the renderer object
            renderer.Dispose();
            // Display a message
            Console.WriteLine("Report generated successfully!");
        }
    }

    public class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }

    public class PersonContract : Contract<Person>
    {
        public PersonContract(Person person)
        {
            Requires()
                .IsNotNull(person, nameof(person))
                .IsNotEmpty(person.Name, nameof(person.Name), "Name is required")
                .IsGreaterThan(person.Age, 0, nameof(person.Age), "Age must be a positive number");
        }
    }
}

using IronPdf;
using System;
using System.Linq;
using System.Text;
using Flunt.Validations;

namespace ConsoleApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
            // StringBuilder for HTML content
            StringBuilder sb = new StringBuilder();
            var person = new Person { Name = "Jack", Age = -25 };
            var contract = new PersonContract(person);

            if (contract.IsValid)
            {
                Console.WriteLine("Person is valid!");
                sb.Append("<p>Person is valid!</p>");
            }
            else
            {
                sb.Append("<p>Validation failed: </p>");
                foreach (var notification in contract.Notifications)
                {
                    sb.Append($"- {notification.Key}: {notification.Message}<br>");
                }
            }

            var renderer = new HtmlToPdf();
            // Set HTML content for the page
            var pdfDocument = renderer.RenderHtmlAsPdf(sb.ToString());
            // Save the document
            pdfDocument.SaveAs("output.pdf");
            // Dispose the renderer object
            renderer.Dispose();
            // Display a message
            Console.WriteLine("Report generated successfully!");
        }
    }

    public class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }

    public class PersonContract : Contract<Person>
    {
        public PersonContract(Person person)
        {
            Requires()
                .IsNotNull(person, nameof(person))
                .IsNotEmpty(person.Name, nameof(person.Name), "Name is required")
                .IsGreaterThan(person.Age, 0, nameof(person.Age), "Age must be a positive number");
        }
    }
}

Below is the execution output from the above code:

Conclusion

IronPDF and Flunt are two strong C# libraries that work well together to streamline workflows for document creation and data validation. With IronPDF's sophisticated PDF production features and Flunt's strong validation capabilities, developers can construct dependable, effective, and high-caliber solutions for a variety of applications. Flunt and IronPDF equip developers with the tools necessary to create high-quality software that meets the needs of users and stakeholders, whether they are developing desktop apps, web applications, or cloud-based solutions.

A year of software support, a permanent license, and a library upgrade are all included in the $799 Lite bundle. IronPDF provides free licensing details of IronPDF for further details regarding cost and license requirements. For additional information about the Iron Software libraries, visit the Iron Software official website.