Flattened struct helper functions

xsd-parser/src/config/renderer.rs

@@ -195,6 +195,17 @@ pub enum RenderStep {
     /// that the serializer can discover which XML namespaces are actually needed
     /// at runtime before writing the root start element.
     QuickXmlCollectNamespaces,
+
+    /// Renderer that generates ergonomic helper accessors for flattened struct content.
+    ///
+    /// This targets the pattern:
+    ///  pub struct Foo { pub content: Vec<FooContent>, ... }
+    /// pub enum FooContent { PrivateNote(String), ... }
+    /// and generates:
+    /// impl Foo {
+    ///   pub fn private_note(&self) -> Option<&String> { ... }
+    /// }
+    ContentHelpers,
 }
 
 /// Helper trait to deal with custom render steps.
@@ -250,6 +261,7 @@ impl RenderStepConfig for RenderStep {
             Self::QuickXmlSerialize { .. } => RenderStepType::ExtraImpls,
             Self::QuickXmlDeserialize { .. } => RenderStepType::ExtraImpls,
             Self::QuickXmlCollectNamespaces => RenderStepType::ExtraImpls,
+            Self::ContentHelpers => RenderStepType::ExtraImpls,
         }
     }
 
@@ -259,11 +271,11 @@ impl RenderStepConfig for RenderStep {
 
     fn into_render_step(self: Box<Self>) -> Box<dyn RenderStepTrait> {
         use crate::pipeline::renderer::{
-            DefaultsRenderStep, EnumConstantsRenderStep, NamespaceConstantsRenderStep,
-            PrefixConstantsRenderStep, QuickXmlCollectNamespacesRenderStep,
-            QuickXmlDeserializeRenderStep, QuickXmlSerializeRenderStep,
-            SerdeQuickXmlTypesRenderStep, SerdeXmlRsV7TypesRenderStep, SerdeXmlRsV8TypesRenderStep,
-            TypesRenderStep, WithNamespaceTraitRenderStep,
+            ContentHelpersRenderStep, DefaultsRenderStep, EnumConstantsRenderStep,
+            NamespaceConstantsRenderStep, PrefixConstantsRenderStep,
+            QuickXmlCollectNamespacesRenderStep, QuickXmlDeserializeRenderStep,
+            QuickXmlSerializeRenderStep, SerdeQuickXmlTypesRenderStep, SerdeXmlRsV7TypesRenderStep,
+            SerdeXmlRsV8TypesRenderStep, TypesRenderStep, WithNamespaceTraitRenderStep,
         };
 
         match *self {
@@ -291,16 +303,17 @@ impl RenderStepConfig for RenderStep {
                 Box::new(QuickXmlDeserializeRenderStep { boxed_deserializer })
             }
             Self::QuickXmlCollectNamespaces => Box::new(QuickXmlCollectNamespacesRenderStep),
+            Self::ContentHelpers => Box::new(ContentHelpersRenderStep),
         }
     }
 
     fn is_mutual_exclusive_to(&self, other: &dyn RenderStepConfig) -> bool {
         use crate::pipeline::renderer::{
-            DefaultsRenderStep, EnumConstantsRenderStep, NamespaceConstantsRenderStep,
-            PrefixConstantsRenderStep, QuickXmlCollectNamespacesRenderStep,
-            QuickXmlDeserializeRenderStep, QuickXmlSerializeRenderStep,
-            SerdeQuickXmlTypesRenderStep, SerdeXmlRsV7TypesRenderStep, SerdeXmlRsV8TypesRenderStep,
-            TypesRenderStep, WithNamespaceTraitRenderStep,
+            ContentHelpersRenderStep, DefaultsRenderStep, EnumConstantsRenderStep,
+            NamespaceConstantsRenderStep, PrefixConstantsRenderStep,
+            QuickXmlCollectNamespacesRenderStep, QuickXmlDeserializeRenderStep,
+            QuickXmlSerializeRenderStep, SerdeQuickXmlTypesRenderStep, SerdeXmlRsV7TypesRenderStep,
+            SerdeXmlRsV8TypesRenderStep, TypesRenderStep, WithNamespaceTraitRenderStep,
         };
 
         if self
@@ -359,6 +372,7 @@ impl RenderStepConfig for RenderStep {
             (Self::QuickXmlCollectNamespaces, None) => {
                 other_id == TypeId::of::<QuickXmlCollectNamespacesRenderStep>()
             }
+            (Self::ContentHelpers, None) => other_id == TypeId::of::<ContentHelpersRenderStep>(),
             _ => false,
         }
     }
@@ -380,7 +394,8 @@ impl RenderStep {
             | (Self::WithNamespaceTrait, Self::WithNamespaceTrait)
             | (Self::QuickXmlSerialize { .. }, Self::QuickXmlSerialize { .. })
             | (Self::QuickXmlDeserialize { .. }, Self::QuickXmlDeserialize { .. })
-            | (Self::QuickXmlCollectNamespaces, Self::QuickXmlCollectNamespaces) => true,
+            | (Self::QuickXmlCollectNamespaces, Self::QuickXmlCollectNamespaces)
+            | (Self::ContentHelpers, Self::ContentHelpers) => true,
             (_, _) => false,
         }
     }

xsd-parser/src/models/mod.rs

@@ -29,4 +29,4 @@ pub use self::name::Name;
 pub use self::naming::{
     format_ident, format_unknown_variant, make_type_name, unify_string, ExplicitNameBuilder,
     ExplicitNaming, NameBuilder, Naming,
-};
+};

xsd-parser/src/pipeline/renderer/mod.rs

@@ -43,11 +43,11 @@ pub use self::custom::{ValueRenderer, ValueRendererBox};
 pub use self::error::Error;
 pub use self::meta::MetaData;
 pub use self::steps::{
-    DefaultsRenderStep, EnumConstantsRenderStep, NamespaceConstantsRenderStep,
-    NamespaceSerialization, PrefixConstantsRenderStep, QuickXmlCollectNamespacesRenderStep,
-    QuickXmlDeserializeRenderStep, QuickXmlSerializeRenderStep, SerdeQuickXmlTypesRenderStep,
-    SerdeXmlRsV7TypesRenderStep, SerdeXmlRsV8TypesRenderStep, TypesRenderStep,
-    WithNamespaceTraitRenderStep,
+    DefaultsRenderStep, EnumConstantsRenderStep, ContentHelpersRenderStep,
+    NamespaceConstantsRenderStep, NamespaceSerialization, PrefixConstantsRenderStep,
+    QuickXmlCollectNamespacesRenderStep, QuickXmlDeserializeRenderStep,
+    QuickXmlSerializeRenderStep, SerdeQuickXmlTypesRenderStep, SerdeXmlRsV7TypesRenderStep,
+    SerdeXmlRsV8TypesRenderStep, TypesRenderStep, WithNamespaceTraitRenderStep,
 };
 
 /// The [`Renderer`] is the central orchestrator for Rust code generation from

xsd-parser/src/pipeline/renderer/steps/content_helper.rs

@@ -0,0 +1,115 @@
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote};
+
+use crate::models::data::{ComplexData, ComplexDataEnum, DataTypeVariant, Occurs};
+use crate::pipeline::renderer::{Context, RenderStep, RenderStepType};
+
+/// RenderStep that generates ergonomic helper accessors for flattened struct content.
+///
+/// This targets the pattern:
+///   pub struct Foo { pub content: Vec<FooContent>, ... }
+///   pub enum FooContent { PrivateNote(String), ... }
+///
+/// and generates:
+///   impl Foo {
+///     pub fn private_note(&self) -> Option<&String> { ... }
+///   }
+#[derive(Debug, Clone, Copy)]
+pub struct ContentHelpersRenderStep;
+
+impl RenderStep for ContentHelpersRenderStep {
+    fn render_step_type(&self) -> RenderStepType {
+        RenderStepType::ExtraImpls
+    }
+
+    fn render_type(&mut self, ctx: &mut Context<'_, '_>) {
+        let DataTypeVariant::Complex(complex) = &ctx.data.variant else {
+            return;
+        };
+        let ComplexData::Struct {
+            type_,
+            content_type,
+        } = complex
+        else {
+            return;
+        };
+        let Some(content) = type_.content() else {
+            return;
+        };
+        if content.occurs != Occurs::DynamicList {
+            return;
+        };
+
+        // The content enum is stored inline as content_type of ComplexData::Struct
+        let Some(content_type) = content_type else {
+            return;
+        };
+
+        let impl_block = match content_type.as_ref() {
+            ComplexData::Enum {
+                type_: enum_type, ..
+            } => render_helpers_for_complex_enum(
+                ctx,
+                &type_.base.type_ident,
+                &content.field_ident,
+                enum_type,
+            ),
+            ComplexData::Struct { .. } => {
+                // Struct content (e.g. a sequence) - no enum variants to flatten
+                return;
+            }
+        };
+
+        ctx.current_module().append(impl_block);
+    }
+}
+
+/// Generate helper accessor methods for a [`ComplexDataEnum`] content type.
+fn render_helpers_for_complex_enum(
+    ctx: &Context<'_, '_>,
+    struct_ident: &proc_macro2::Ident,
+    content_field_ident: &proc_macro2::Ident,
+    enum_type: &ComplexDataEnum<'_>,
+) -> TokenStream {
+    let enum_ident = &enum_type.base.type_ident;
+
+    let methods = enum_type.elements.iter().filter_map(|e| {
+        if e.occurs != Occurs::Single {
+            return None;
+        }
+        let variant_ident = &e.variant_ident;
+        let method_ident = &e.field_ident;
+        let mut_method = format!("{}_mut", method_ident).replace("__", "_");
+        let mut_method_ident = format_ident!("{mut_method}");
+        let target_ty = ctx.resolve_type_for_module(&e.target_type);
+        let option = ctx.resolve_build_in("::core::option::Option");
+
+        let out = quote! {
+            #[inline]
+            pub fn #method_ident(&self) -> #option<&#target_ty> {
+                self.#content_field_ident.iter().find_map(|x| {
+                    match x {
+                        #enum_ident::#variant_ident(v) => #option::Some(v),
+                        _ => #option::None,
+                    }
+                })
+            }
+            #[inline]
+            pub fn #mut_method_ident(&mut self) -> #option<&mut #target_ty> {
+                self.#content_field_ident.iter_mut().find_map(|x| {
+                    match x {
+                        #enum_ident::#variant_ident(v) => #option::Some(v),
+                        _ => #option::None,
+                    }
+                })
+            }
+        };
+        Some(out)
+    });
+
+    quote! {
+        impl #struct_ident {
+            #( #methods )*
+        }
+    }
+}

xsd-parser/src/pipeline/renderer/steps/mod.rs

@@ -1,5 +1,6 @@
 mod defaults;
 mod enum_const;
+mod content_helper;
 mod namespace_const;
 mod prefix_const;
 mod quick_xml;
@@ -24,6 +25,7 @@ use super::Context;
 
 pub use self::defaults::DefaultsRenderStep;
 pub use self::enum_const::EnumConstantsRenderStep;
+pub use self::content_helper::ContentHelpersRenderStep;
 pub use self::namespace_const::NamespaceConstantsRenderStep;
 pub use self::prefix_const::PrefixConstantsRenderStep;
 pub use self::quick_xml::{

xsd-parser/tests/feature/flattened_content_helpers/example/default.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Foo xmlns="http://example.com">
+    <Bar>hello</Bar>
+    <Baz>42</Baz>
+    <Bar>world</Bar>
+</Foo>

xsd-parser/tests/feature/flattened_content_helpers/expected/default.rs

@@ -0,0 +1,40 @@
+pub type Foo = FooType;
+#[derive(Debug)]
+pub struct FooType {
+    pub content: Vec<FooTypeContent>,
+}
+#[derive(Debug)]
+pub enum FooTypeContent {
+    Bar(String),
+    Baz(i32),
+}
+impl FooType {
+    #[inline]
+    pub fn bar(&self) -> Option<&String> {
+        self.content.iter().find_map(|x| match x {
+            FooTypeContent::Bar(v) => Option::Some(v),
+            _ => Option::None,
+        })
+    }
+    #[inline]
+    pub fn bar_mut(&mut self) -> Option<&mut String> {
+        self.content.iter_mut().find_map(|x| match x {
+            FooTypeContent::Bar(v) => Option::Some(v),
+            _ => Option::None,
+        })
+    }
+    #[inline]
+    pub fn baz(&self) -> Option<&i32> {
+        self.content.iter().find_map(|x| match x {
+            FooTypeContent::Baz(v) => Option::Some(v),
+            _ => Option::None,
+        })
+    }
+    #[inline]
+    pub fn baz_mut(&mut self) -> Option<&mut i32> {
+        self.content.iter_mut().find_map(|x| match x {
+            FooTypeContent::Baz(v) => Option::Some(v),
+            _ => Option::None,
+        })
+    }
+}

xsd-parser/tests/feature/flattened_content_helpers/mod.rs

@@ -0,0 +1,18 @@
+use xsd_parser::{pipeline::renderer::ContentHelpersRenderStep, Config, IdentType};
+
+use crate::utils::{generate_test, ConfigEx};
+
+fn config() -> Config {
+    Config::test_default()
+        .with_render_step(ContentHelpersRenderStep)
+        .with_generate([(IdentType::Element, "tns:Foo")])
+}
+
+#[test]
+fn generate_default() {
+    generate_test(
+        "tests/feature/flattened_content_helpers/schema.xsd",
+        "tests/feature/flattened_content_helpers/expected/default.rs",
+        config(),
+    );
+}

xsd-parser/tests/feature/flattened_content_helpers/schema.xsd

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+    xmlns:tns="http://example.com"
+    targetNamespace="http://example.com"
+    elementFormDefault="qualified">
+
+    <xs:complexType name="FooType">
+        <xs:choice maxOccurs="unbounded">
+            <xs:element name="Bar" type="xs:string" />
+            <xs:element name="Baz" type="xs:int" />
+        </xs:choice>
+    </xs:complexType>
+
+    <xs:element name="Foo" type="tns:FooType" />
+</xs:schema>

xsd-parser/tests/feature/mod.rs

@@ -19,6 +19,7 @@ mod complex_type_with_repeated_content;
 mod content_display_name;
 mod custom_type;
 mod defaultable_content;
+mod flattened_content_helpers;
 mod derive;
 mod documentation;
 mod duplicate_idents;