Fix simple bindings with template soure

blueprintcompiler/outputs/xml/__init__.py

@@ -114,7 +114,16 @@ class XmlOutput(OutputFormat):
 
         elif isinstance(value, Binding):
             if simple := value.simple_binding:
-                props["bind-source"] = simple.source
+                if (
+                    simple.source == "template"
+                    and value.context[ScopeCtx].template is not None
+                ):
+                    props["bind-source"] = value.context[
+                        ScopeCtx
+                    ].template.gir_class.glib_type_name
+                else:
+                    props["bind-source"] = simple.source
+
                 props["bind-property"] = simple.property_name
                 props["bind-flags"] = "sync-create"
                 xml.put_self_closing("property", **props)

tests/samples/template_simple_binding.blp

@@ -0,0 +1,5 @@
+using Gtk 4.0;
+
+template $MyTemplate {
+  prop: bind template.prop2;
+}

tests/samples/template_simple_binding.ui

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <requires lib="gtk" version="4.0"/>
+  <template class="MyTemplate">
+    <property name="prop" bind-source="MyTemplate" bind-property="prop2" bind-flags="sync-create"/>
+  </template>
+</interface>

tests/test_samples.py

@@ -178,6 +178,7 @@ class TestSamples(unittest.TestCase):
                 "template_binding",
                 "template_binding_extern",
                 "template_no_parent",
+                "template_simple_binding",
                 "typeof",
                 "unchecked_class",
             ]