Question

I didn’t know what else to title this post, so if you have a better title, feel free to edit.

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I have two classes: Form and Field.

Form has a property called Fields that is a List of Field objects.

Form has a property called Prefix.

Field has a method that needs to use the Prefix property of the Form that contains it.

Here is what I am doing now:

class Form
    {
        private List<Field> fields;
        public string Prefix { get; set; }

        public void AddField(Field field)
        {
            field.Form = this;
            fields.Add(field);
        }
    }

    class Field
    {
        public void RenderHtml()
        {
            // render html element with ID attribute
            // prefixed with the parent form's Prefix property
        }
    }

How should I do this?

Answer 1

I would do this:

class Form
{
    // ...
}

class Field
{
    Form parent;

    public Field(Form parent)
    {
        if (parent == null)
        {
            throw new ArgumentNullException("parent");
        }

        this.parent = parent;
    }

    // now you can reference this.parent to get at its owning form
    // ...
}