I am fairly new to c# and would like to know how values can be called from a file instead of statically hard coding it in the class. I know in java spring boot applications we can have it in application.properties files. In my case I have the db hostname, username and pwd stored in a file

namespace NunitTestCase
{
    [TestFixture]
    public class Test
    {   
        string query = "SELECT * FROM SYSTEM.ADMIN.EMPLOYEE";
        string host = "vm1.test.app.com";  //want these data in a file
        int port = 5480;
        string dbName = "SYSTEM";
        string userName = "admin";
        string password = "password";
        
        [Test]
        public void TestCase()
        {
            var builder = new ConnectionStringBuilder();
            builder.UserName = userName;
            builder.Password = password;
            builder.Port = port;
            builder.Host = host;
            builder.Database = dbName;

            using (var con = new Connection(builder.ConnectionString))
            {
                con.Open();
                NUnit.Framework.Assert.That(con.State == ConnectionState.Open);
                using (var cmd = new Command(query, con))
                {
                    var rdr = cmd.ExecuteReader();
                    while (rdr.Read())
                    {
                        for (int i = 0; i < rdr.FieldCount; i  )
                        {
                            object o = null;
                            try
                            {
                                o = rdr.GetValue(i);
                            }
                            catch (Exception ex)
                            {
                                o = ex.Message;
                            }
                            
                            Console.WriteLine(o);
                        }
                    }
                }
                con.Close();
                NUnit.Framework.Assert.That(con.State == ConnectionState.Closed);
            }
        }
    }
}

file.yaml

database:
   host: "vm1.test.app.com"
   port: 5480
   dbName: "SYSTEM"
   userName: "admin"
   password: "password"

How do I make changes in my code so that instead of hardcoding, these values can be picked up from the file

CodePudding user response：

1. Traditionally, in .net we store configuration in .json/.xml files and C# supports built-in functionality to parse it, but as far as you are using .YAML file you can install the library to parse this file: YAMLDotNet and use this to parse.

public class Database {
    public string Host { get; set; }
    public string Port { get; set; }
    public string DbName { get; set; }
    public string UserName { get; set; }
    public string Password { get; set; }
 } 
 public class Configuration
 {
    public Database Database { get; set; }
 }

    var yamlString = File.ReadAllText(@"...\file.yaml");
    
    var deserializer = new DeserializerBuilder().WithNamingConvention(new CamelCaseNamingConvention()).Build();
    
    var config = deserializer.Deserialize<Configuration>(yamlString);

2. If you don't want to use any libraries you can parse it manually, so create a class which reflects your model in YAML, something like:

Function to get the value of a property:

    public string GetValueOfPropertyYaml(string yamlStr) {
        return yamlStr?.Split(":")?.Skip(1)?.FirstOrDefault()?.Trim() ?? string.Empty;
    }

Main code:

        string[] yamlStringArray = File.ReadAllLines(@"..\file.yaml");
        var config = new Database();
        foreach (var yamlStr in yamlStringArray) {
            if (yamlStr.Contains("host:")) {
                config.Host = GetValueOfPropertyYaml(yamlStr);
            }
            if (yamlStr.Contains("port:"))
            {
                config.Port = GetValueOfPropertyYaml(yamlStr);
            }
            if (yamlStr.Contains("dbName:"))
            {
                config.DbName = GetValueOfPropertyYaml(yamlStr);
            }
            if (yamlStr.Contains("userName:"))
            {
                config.UserName = GetValueOfPropertyYaml(yamlStr);
            }
            if (yamlStr.Contains("password:"))
            {
                config.Password = GetValueOfPropertyYaml(yamlStr);
            }
        }
        ;
        // use filled `config` variable below.

your model:

public class Database
{
    public string Host { get; set; }
    public string Port { get; set; }
    public string DbName { get; set; }
    public string UserName { get; set; }
    public string Password { get; set; }
}

NOTE: I highly recommend you to use library, because it was already tested and worked perfectly(my method should be tested properly)