private static object LateBindHelperExpression(BindingContext context, string helperName, object[] arguments)
{
var configuration = context.Configuration;
if (configuration.Helpers.TryGetValue(helperName, out var helper))
{
using (var write = new PolledStringWriter(configuration.FormatProvider))
{
helper(write, context.Value, arguments);
return(write.ToString());
}
}
if (configuration.ReturnHelpers.TryGetValue(helperName, out var returnHelper))
{
return(returnHelper(context.Value, arguments));
}
var pureHelperName = helperName.Substring(1);
foreach (var resolver in configuration.HelperResolvers)
{
if (resolver.TryResolveReturnHelper(pureHelperName, arguments.FirstOrDefault()?.GetType(), out returnHelper))
{
return(returnHelper(context.Value, arguments));
}
}
throw new HandlebarsRuntimeException($"Template references a helper that is not registered. Could not find helper '{helperName}'");
}
internal Action <TextWriter, object> CompileView(string templatePath,
InternalHandlebarsConfiguration configuration)
{
var fs = _configuration.FileSystem;
if (fs == null)
{
throw new InvalidOperationException("Cannot compile view when configuration.FileSystem is not set");
}
var template = fs.GetFileContent(templatePath);
if (template == null)
{
throw new InvalidOperationException("Cannot find template at '" + templatePath + "'");
}
IEnumerable <object> tokens;
using (var sr = new StringReader(template))
{
using (var reader = new ExtendedStringReader(sr))
{
tokens = Tokenizer.Tokenize(reader).ToList();
}
}
var layoutToken = tokens.OfType <LayoutToken>().SingleOrDefault();
var expressionBuilder = new ExpressionBuilder(configuration);
var expressions = expressionBuilder.ConvertTokensToExpressions(tokens);
var compiledView = FunctionBuilder.Compile(expressions, configuration, templatePath);
if (layoutToken == null)
{
return(compiledView);
}
var layoutPath = fs.Closest(templatePath, layoutToken.Value + ".hbs");
if (layoutPath == null)
{
throw new InvalidOperationException("Cannot find layout '" + layoutPath + "' for template '" +
templatePath + "'");
}
var compiledLayout = CompileView(layoutPath, configuration);
return((tw, vm) =>
{
string inner;
using (var innerWriter = new PolledStringWriter(configuration.FormatProvider))
{
compiledView(innerWriter, vm);
inner = innerWriter.ToString();
}
compiledLayout(tw, new DynamicViewModel(new[] { new { body = inner }, vm }));
});
}
