private void WriteCSharpExpression(CSharpExpressionIRNode node)
{
for (var i = 0; i < node.Children.Count; i++)
{
if (node.Children[i] is RazorIRToken token && token.IsCSharp)
{
Context.Writer.Write(token.Content);
}
private CSharpExpressionIRNode MakeCSharpExpressionIRNode(RazorIRNode parent, string csharpExpressionContent)
{
var content = new CSharpExpressionIRNode {
Parent = parent, Source = parent.Source
};
content.Children.Add(new RazorIRToken {
Kind = RazorIRToken.TokenKind.CSharp,
Parent = content,
Source = parent.Source,
Content = csharpExpressionContent
});
return(content);
}
// Implements the @bind(...) syntax
private bool TryAddBindExpression(RazorIRToken token)
{
const string bindExpressionStart = "bind(";
const string bindExpressionEnd = ")";
if (token.Content.StartsWith(bindExpressionStart) && token.Content.EndsWith(bindExpressionEnd))
{
// Extract "expr" from "bind(expr)"
var boundExpression = token.Content.Substring(
bindExpressionStart.Length,
token.Content.Length - bindExpressionStart.Length - bindExpressionEnd.Length);
// We can't work out the final binding expression code yet, because we don't yet know what
// type of element this is going onto (there might be a "type='checkbox'" or similar that
// appears *after* the @bind(...)). So just store the expression for later use.
_nextElementBoundExpression = MakeCSharpExpressionIRNode(token, boundExpression);
return(true);
}
return(false);
}
public override void VisitCSharpExpression(CSharpExpressionIRNode node)
{
// Is this a "bind(expr)" expression?
if (node.Children.Count == 1)
{
var child = node.Children[0] as RazorIRToken;
if (child != null && child.IsCSharp)
{
if (TryAddBindExpression(child))
{
return;
}
}
}
if (!string.IsNullOrEmpty(_unconsumedHtml))
{
// We're in the middle of writing out an element tag. This C# expression might represent an entire
// attribute (e.g., @onclick(...)), or it might represent the value of an attribute (e.g., something=@value).
// Differentiate based on whether the unconsumed HTML ends with " attribute=".
var incompleteAttributeMatch = _incompleteAttributeRegex.Match(_unconsumedHtml);
if (incompleteAttributeMatch.Success)
{
var wholeMatchText = incompleteAttributeMatch.Groups[0];
var attributeName = incompleteAttributeMatch.Groups["name"].Value;
_unconsumedHtml = _unconsumedHtml.Substring(0, _unconsumedHtml.Length - wholeMatchText.Length + 1);
_nextElementAttributes[attributeName] = node;
}
else
{
// There's no incomplete attribute, so the C# expression must represent an entire attribute
_nextElementAttributeExpressions.Add(node);
}
}
else
{
// We're between tags, so treat it as an @someVar expression to be rendered as a text node
WriteCSharpExpressionAsTextNode(++_sourceSequence, _context, node);
}
}
