Fixing nested for loops

knightmeister · Mar 14, 2019 · f2aa794 · f2aa794
1 parent 1d2fccc
commit f2aa794
Show file tree

Hide file tree

Showing 2 changed files with 39 additions and 1 deletion.
diff --git a/Fluid.Tests/ForStatementTests.cs b/Fluid.Tests/ForStatementTests.cs
@@ -153,6 +153,40 @@ public async Task ForShouldProvideHelperVariables()
             Assert.Equal("31023truefalse32112falsefalse33201falsetrue", sw.ToString());
         }
 
+        [Fact]
+        public async Task ForShouldBeNestable()
+        {
+            var nested = new ForStatement(
+                new List<Statement> {
+                    CreateMemberStatement("forloop.index")
+                },
+                "j",
+                new MemberExpression(
+                    new IdentifierSegment("items")
+                ),
+                null, null, false
+            );
+
+            var outer = new ForStatement(
+                new List<Statement> {
+                    CreateMemberStatement("forloop.index"),
+                    nested
+                },
+                "i",
+                new MemberExpression(
+                    new IdentifierSegment("items")
+                ),
+                null, null, false
+            );
+
+            var sw = new StringWriter();
+            var context = new TemplateContext();
+            context.SetValue("items", new[] { 1, 2, 3 });
+            await outer.WriteToAsync(sw, HtmlEncoder.Default, context);
+
+            Assert.Equal("112321233123", sw.ToString());
+        }
+
         [Fact]
         public async Task ForEvaluatesOptions()
         {
@@ -174,7 +208,6 @@ public async Task ForEvaluatesOptions()
             Assert.Equal("543", sw.ToString());
         }
 
-
         Statement CreateMemberStatement(string p)
         {
             return new OutputStatement(new MemberExpression(p.Split('.').Select(x => new IdentifierSegment(x)).ToArray()));

diff --git a/Fluid/Ast/ForStatement.cs b/Fluid/Ast/ForStatement.cs
@@ -120,6 +120,7 @@ public override async ValueTask<Completion> WriteToAsync(TextWriter writer, Text
                 var forloop = new ForLoopValue();
 
                 var length = forloop.Length = list.Count;
+
                 context.SetValue("forloop", forloop);
 
                 for (var i = 0; i < length; i++)
@@ -143,6 +144,10 @@ public override async ValueTask<Completion> WriteToAsync(TextWriter writer, Text
                         var statement = Statements[index];
                         completion = await statement.WriteToAsync(writer, encoder, context);
 
+                        // Restore the forloop property after every statement in case it replaced it,
+                        // for instance if it contains a nested for loop
+                        context.SetValue("forloop", forloop);
+
                         if (completion != Completion.Normal)
                         {
                             // Stop processing the block statements