extension instances and extension definitions can be extended

jktjkt · bedrich-schindler · jktjkt · commit 0ef451624fe4 · 2024-09-23T20:37:02.000+02:00
This was inspired by a patch from Bedrich
(Ib0dfb68afaf0f74d3defe87b16b7c34457cc4899); I preserved the
implementation, but I really wanted to document what is going on.

Change-Id: I228430278de1cfa7ac192574d25e50cf157c70a1
Co-authored-by: Bed&#345;ich Schindler &lt;bedrich.schindler@gmail.com&gt;
diff --git a/include/libyang-cpp/Module.hpp b/include/libyang-cpp/Module.hpp
@@ -165,6 +165,7 @@ class LIBYANG_CPP_EXPORT ExtensionInstance {
     Module module() const;
     Extension definition() const;
     std::optional<std::string> argument() const;
+    std::vector<ExtensionInstance> extensionInstances() const;
 
 private:
     ExtensionInstance(const lysc_ext_instance* instance, std::shared_ptr<ly_ctx> ctx);
@@ -175,6 +176,7 @@ class LIBYANG_CPP_EXPORT ExtensionInstance {
     friend Module;
     friend Context;
     friend DataNode;
+    friend Extension;
     friend SchemaNode;
 };
 
@@ -187,6 +189,7 @@ class LIBYANG_CPP_EXPORT Extension {
 public:
     Module module() const;
     std::string name() const;
+    std::vector<ExtensionInstance> extensionInstances() const;
 
 private:
     Extension(const lysc_ext* def, std::shared_ptr<ly_ctx> ctx);
diff --git a/src/Module.cpp b/src/Module.cpp
@@ -427,6 +427,20 @@ Extension ExtensionInstance::definition() const
     return Extension{m_instance->def, m_ctx};
 }
 
+/**
+ * @brief Returns instances of extensions which are extending this particular extensions instance
+ *
+ * Wraps `lysc_ext_instance::exts`.
+ */
+std::vector<ExtensionInstance> ExtensionInstance::extensionInstances() const
+{
+    std::vector<ExtensionInstance> res;
+    for (const auto& ext : std::span(m_instance->exts, LY_ARRAY_COUNT(m_instance->exts))) {
+        res.emplace_back(ExtensionInstance{&ext, m_ctx});
+    }
+    return res;
+}
+
 Extension::Extension(const lysc_ext* ext, std::shared_ptr<ly_ctx> ctx)
     : m_ext(ext)
     , m_ctx(ctx)
@@ -455,4 +469,18 @@ std::string Extension::name() const
 {
     return m_ext->name;
 }
+
+/**
+ * @brief Returns all extension instances which extend this extension definition
+ *
+ * Wraps `lysc_ext::exts`.
+ */
+std::vector<ExtensionInstance> Extension::extensionInstances() const
+{
+    std::vector<ExtensionInstance> res;
+    for (const auto& ext : std::span(m_ext->exts, LY_ARRAY_COUNT(m_ext->exts))) {
+        res.emplace_back(ExtensionInstance{&ext, m_ctx});
+    }
+    return res;
+}
 }
diff --git a/tests/example_schema.hpp b/tests/example_schema.hpp
@@ -762,8 +762,14 @@ module augmenting-extensions {
   import with-extensions {
     prefix "we";
   }
+  extension another-annotation {
+    we:annotation wtf-is-this;
+  }
   augment "/we:c" {
-    we:annotation last-modified;
+    we:annotation last-modified {
+      ae:another-annotation {
+      }
+    }
   }
 }
 )"s;
diff --git a/tests/schema_node.cpp b/tests/schema_node.cpp
@@ -374,6 +374,19 @@ TEST_CASE("SchemaNode")
         REQUIRE(elem.extensionInstances()[0].definition().module().name() == "with-extensions");
         REQUIRE(elem.extensionInstances()[0].definition().name() == "annotation");
         REQUIRE(elem.extensionInstances()[0].argument() == "last-modified");
+        // a funny thing about an extension instance is that it can be also extended...
+        REQUIRE(elem.extensionInstances()[0].extensionInstances().size() == 1);
+        REQUIRE(elem.extensionInstances()[0].extensionInstances()[0].module().name() == "augmenting-extensions");
+        REQUIRE(elem.extensionInstances()[0].extensionInstances()[0].definition().module().name() == "augmenting-extensions");
+        REQUIRE(elem.extensionInstances()[0].extensionInstances()[0].definition().name() == "another-annotation");
+        REQUIRE(!elem.extensionInstances()[0].extensionInstances()[0].argument());
+        // ...and of course extension definitions are no exception and can be extended as well, yay!
+        REQUIRE(elem.extensionInstances()[0].extensionInstances()[0].definition().extensionInstances().size() == 1);
+        REQUIRE(elem.extensionInstances()[0].extensionInstances()[0].definition().extensionInstances()[0].module().name() == "augmenting-extensions");
+        REQUIRE(elem.extensionInstances()[0].extensionInstances()[0].definition().extensionInstances()[0].definition().module().name() == "with-extensions");
+        REQUIRE(elem.extensionInstances()[0].extensionInstances()[0].definition().extensionInstances()[0].definition().name() == "annotation");
+        REQUIRE(elem.extensionInstances()[0].extensionInstances()[0].definition().extensionInstances()[0].argument() == "wtf-is-this");
+        // OK, enough with that. These are the "old" extensions from the original module pre-augmentation:
         REQUIRE(elem.extensionInstances()[1].module().name() == "with-extensions");
         REQUIRE(elem.extensionInstances()[1].definition().module().name() == "ietf-netconf-acm");
         REQUIRE(elem.extensionInstances()[1].definition().name() == "default-deny-write");

Original file line number	Diff line number	Diff line change
`@@ -762,8 +762,14 @@ module augmenting-extensions {`
`762`	`762`	`import with-extensions {`
`763`	`763`	`prefix "we";`
`764`	`764`	`}`
	`765`	`+ extension another-annotation {`
	`766`	`+ we:annotation wtf-is-this;`
	`767`	`+ }`
`765`	`768`	`augment "/we:c" {`
`766`		`- we:annotation last-modified;`
	`769`	`+ we:annotation last-modified {`
	`770`	`+ ae:another-annotation {`
	`771`	`+ }`
	`772`	`+ }`
`767`	`773`	`}`
`768`	`774`	`}`
`769`	`775`	`)"s;`