Get all properties from a view model to display in array

Question

I have a view model that have a lot of properties, and I created a custom attribute for send the data to hubspot, because hubspot need a specific nomenclature, then I need to create a method that have some king of iterator, that for every property that contain my custom attribute he put a specific output, here is the code:

public class CreateTrialUserHubspotViewModel {

    [HubspotAttribute("firstname")]   
    [Display(Name = "First Name")]
    [StringLength(50)]
    [Required]
    public string FirstName { get; set; }

    [HubspotAttribute("lastname")]
    [Display(Name = "Last Name")]
    [StringLength(50)]
    [Required]
    public string LastName { get; set; }

    [HubspotAttribute("jobtitle")]
    [Display(Name = "Job title")]
    [StringLength(50)]
    [Required]
    public string JobTitle { get; set; }
}

Now this is my custom attribute

[AttributeUsage(AttributeTargets.All)]
public class HubspotAttribute : System.Attribute {
    public readonly string hubspotValue;

    public HubspotAttribute(string value)
    {
        this.hubspotValue = value;
    }
}

And then I need to create a method that take a viewmodel object and create my output, I need some suggest about how to do that, will be something like this:

private static RowValidation ValidateRowWithManifest<T>(CreateTrialUserHubspotViewModel trialUser) {
        RowValidation validation = new RowValidation();

        FieldInfo[] fields = typeof(T).GetPropertiesOfSomeWay;

        foreach (DataType field in fields) {
           output+=whatINeed
        }
        return validation;
    }
}

The needed output will be like: [firstname:"pepe", lastname="perez", jobtitle"none"]. just calling that method will return all the data I need.

Answer 1

If you are looking for something that will concatenate properties into a string that looks like a JSON string (and that would be a better way to handle it), you can use something like the following:

private static string CreateOutput(CreateTrialUserHubspotViewModel trialUser)
{
    var properties = trialUser.GetType().GetProperties().Where(x => Attribute.IsDefined(x, typeof(HubspotAttribute))).ToList();

    var values = properties.Select(x =>
    {
        var att = x.GetCustomAttribute(typeof(HubspotAttribute));
        var key = ((HubspotAttribute)att).hubspotValue;
        var val = x.GetValue(trialUser);
        return $"{key}:{val}";
    });

    var sb = new StringBuilder();
    values.ToList().ForEach(v =>
    {
        sb.Append(v);
        if (values.Last() != v) sb.Append(',');
    });

    return sb.ToString();
}