MustacheSharp/mustache-sharp/KeyGenerator.cs

73 lines
2.5 KiB
C#

using System;
using System.IO;
using System.Text;
namespace Mustache
{
/// <summary>
/// Substitutes a key placeholder with the textual representation of the associated object.
/// </summary>
internal sealed class KeyGenerator : IGenerator
{
private readonly string _key;
private readonly string _format;
private readonly bool _isVariable;
private readonly bool _isExtension;
/// <summary>
/// Initializes a new instance of a KeyGenerator.
/// </summary>
/// <param name="key">The key to substitute with its value.</param>
/// <param name="alignment">The alignment specifier.</param>
/// <param name="formatting">The format specifier.</param>
/// <param name="isExtension">Specifies whether the key was found within triple curly braces.</param>
public KeyGenerator(string key, string alignment, string formatting, bool isExtension)
{
if (key.StartsWith("@"))
{
_key = key.Substring(1);
_isVariable = true;
}
else
{
_key = key;
_isVariable = false;
}
_format = getFormat(alignment, formatting);
_isExtension = isExtension;
}
private static string getFormat(string alignment, string formatting)
{
StringBuilder formatBuilder = new StringBuilder();
formatBuilder.Append("{0");
if (!String.IsNullOrWhiteSpace(alignment))
{
formatBuilder.Append(",");
formatBuilder.Append(alignment.TrimStart('+'));
}
if (!String.IsNullOrWhiteSpace(formatting))
{
formatBuilder.Append(":");
formatBuilder.Append(formatting);
}
formatBuilder.Append("}");
return formatBuilder.ToString();
}
void IGenerator.GetText(TextWriter writer, Scope scope, Scope context, Action<Substitution> postProcessor)
{
object value = _isVariable ? context.Find(_key, _isExtension) : scope.Find(_key, _isExtension);
string result = String.Format(writer.FormatProvider, _format, value);
Substitution substitution = new Substitution()
{
Key = _key,
Substitute = result,
IsExtension = _isExtension
};
postProcessor(substitution);
writer.Write(substitution.Substitute);
}
}
}