Detailed changes
@@ -388,6 +388,57 @@ fn default_attribute_roundtrip_pp() {
roundtrip_full::<DefaultAttribute>("<attr xmlns='urn:example:ns1' foo='xyz' bar='16'/>");
}
+#[derive(FromXml, AsXml, PartialEq, Debug, Clone)]
+#[xml(namespace = NS1, name = "attr")]
+struct AttributeWithCodec {
+ #[xml(attribute(default, codec = xso::text::EmptyAsNone))]
+ foo: core::option::Option<String>,
+}
+
+#[test]
+fn attribute_with_codec_is_none() {
+ #[allow(unused_imports)]
+ use core::{
+ option::Option::{None, Some},
+ result::Result::{Err, Ok},
+ };
+ let el = parse_str::<AttributeWithCodec>("<attr xmlns='urn:example:ns1'/>").unwrap();
+ assert_eq!(el.foo, None);
+ let el = parse_str::<AttributeWithCodec>("<attr xmlns='urn:example:ns1' foo=''/>").unwrap();
+ assert_eq!(el.foo, None);
+ let el = parse_str::<AttributeWithCodec>("<attr xmlns='urn:example:ns1' foo='bar'/>").unwrap();
+ assert_eq!(el.foo, Some(String::from("bar")));
+}
+
+#[derive(FromXml, AsXml, PartialEq, Debug, Clone)]
+#[xml(namespace = NS1, name = "attr")]
+struct AttributeWithBase64Codec {
+ #[xml(attribute(codec = xso::text::Base64))]
+ foo: Vec<u8>,
+}
+
+#[test]
+fn attribute_with_base64_codec_roundtrip() {
+ #[allow(unused_imports)]
+ use core::{
+ option::Option::{None, Some},
+ result::Result::{Err, Ok},
+ };
+ roundtrip_full::<AttributeWithBase64Codec>("<attr xmlns='urn:example:ns1' foo='AAAA'/>");
+}
+
+#[test]
+fn attribute_with_base64_codec_decodes() {
+ #[allow(unused_imports)]
+ use core::{
+ option::Option::{None, Some},
+ result::Result::{Err, Ok},
+ };
+ let el = parse_str::<AttributeWithBase64Codec>("<attr xmlns='urn:example:ns1' foo='AAAA'/>")
+ .unwrap();
+ assert_eq!(el.foo, [0, 0, 0]);
+}
+
#[derive(FromXml, AsXml, PartialEq, Debug, Clone)]
#[xml(namespace = NS1, name = "text")]
struct TextString {
@@ -14,7 +14,10 @@ use syn::*;
use crate::error_message::{self, ParentRef};
use crate::meta::{Flag, NameRef, NamespaceRef};
use crate::scope::{AsItemsScope, FromEventsScope};
-use crate::types::{as_optional_xml_text_fn, default_fn, from_xml_text_fn};
+use crate::types::{
+ as_optional_xml_text_fn, default_fn, from_xml_text_fn, text_codec_decode_fn,
+ text_codec_encode_fn,
+};
use super::{Field, FieldBuilderPart, FieldIteratorPart, FieldTempInit};
@@ -29,6 +32,9 @@ pub(super) struct AttributeField {
/// Flag indicating whether the value should be defaulted if the
/// attribute is absent.
pub(super) default_: Flag,
+
+ /// Optional codec to use.
+ pub(super) codec: Option<Expr>,
}
impl Field for AttributeField {
@@ -53,7 +59,18 @@ impl Field for AttributeField {
},
};
- let from_xml_text = from_xml_text_fn(ty.clone());
+ let finalize = match self.codec {
+ Some(ref codec) => {
+ let decode = text_codec_decode_fn(ty.clone());
+ quote! {
+ |value| #decode(&#codec, value)
+ }
+ }
+ None => {
+ let from_xml_text = from_xml_text_fn(ty.clone());
+ quote! { #from_xml_text }
+ }
+ };
let on_absent = match self.default_ {
Flag::Absent => quote! {
@@ -70,7 +87,7 @@ impl Field for AttributeField {
Ok(FieldBuilderPart::Init {
value: FieldTempInit {
init: quote! {
- match #attrs.remove(#xml_namespace, #xml_name).map(#from_xml_text).transpose()? {
+ match #attrs.remove(#xml_namespace, #xml_name).map(#finalize).transpose()? {
::core::option::Option::Some(v) => v,
::core::option::Option::None => #on_absent,
}
@@ -96,11 +113,20 @@ impl Field for AttributeField {
};
let xml_name = &self.xml_name;
- let as_optional_xml_text = as_optional_xml_text_fn(ty.clone());
+ let generator = match self.codec {
+ Some(ref codec) => {
+ let encode = text_codec_encode_fn(ty.clone());
+ quote! { #encode(&#codec, #bound_name)? }
+ }
+ None => {
+ let as_optional_xml_text = as_optional_xml_text_fn(ty.clone());
+ quote! { #as_optional_xml_text(#bound_name)? }
+ }
+ };
Ok(FieldIteratorPart::Header {
generator: quote! {
- #as_optional_xml_text(#bound_name)?.map(|#bound_name| ::xso::Item::Attribute(
+ #generator.map(|#bound_name| ::xso::Item::Attribute(
#xml_namespace,
::std::borrow::Cow::Borrowed(#xml_name),
#bound_name,
@@ -253,6 +253,7 @@ fn new_field(
qname: QNameRef { namespace, name },
default_,
type_,
+ codec,
} => {
let xml_name = default_name(span, name, field_ident)?;
@@ -270,6 +271,7 @@ fn new_field(
xml_name,
xml_namespace: namespace,
default_,
+ codec,
}))
}
@@ -689,6 +689,9 @@ pub(crate) enum XmlFieldMeta {
/// An explicit type override, only usable within extracts.
type_: Option<Type>,
+
+ /// The path to the optional codec type.
+ codec: Option<Expr>,
},
/// `#[xml(text)]`
@@ -787,12 +790,14 @@ impl XmlFieldMeta {
},
default_: Flag::Absent,
type_: None,
+ codec: None,
})
} else if meta.input.peek(syn::token::Paren) {
// full syntax
let mut qname = QNameRef::default();
let mut default_ = Flag::Absent;
let mut type_ = None;
+ let mut codec = None;
meta.parse_nested_meta(|meta| {
if meta.path.is_ident("default") {
if default_.is_set() {
@@ -806,6 +811,23 @@ impl XmlFieldMeta {
}
type_ = Some(meta.value()?.parse()?);
Ok(())
+ } else if meta.path.is_ident("codec") {
+ if codec.is_some() {
+ return Err(Error::new_spanned(meta.path, "duplicate `codec` key"));
+ }
+ let (new_codec, helpful_error) = parse_codec_expr(meta.value()?)?;
+ // See the comment at the top of text_from_meta() below for why we
+ // do this.
+ let lookahead = meta.input.lookahead1();
+ if !lookahead.peek(Token![,]) && !meta.input.is_empty() {
+ if let Some(helpful_error) = helpful_error {
+ let mut e = lookahead.error();
+ e.combine(helpful_error);
+ return Err(e);
+ }
+ }
+ codec = Some(new_codec);
+ Ok(())
} else {
match qname.parse_incremental_from_meta(meta)? {
None => Ok(()),
@@ -818,6 +840,7 @@ impl XmlFieldMeta {
qname,
default_,
type_,
+ codec,
})
} else {
// argument-less syntax
@@ -826,6 +849,7 @@ impl XmlFieldMeta {
qname: QNameRef::default(),
default_: Flag::Absent,
type_: None,
+ codec: None,
})
}
}
@@ -29,6 +29,8 @@ Version NEXT:
translated into a boolean (`#[xml(flag)]`).
- Generic TextCodec implementation for all base64 engines provided by
the base64 crate (if the `base64` feature is enabled).
+ - New `codec` field on `attribute` meta, to support decoding and
+ encoding using any `TextCodec`.
Version 0.1.2:
2024-07-26 Jonas Schäfer <jonas@zombofant.net>
@@ -263,6 +263,7 @@ The following keys can be used inside the `#[xml(attribute(..))]` meta:
| `name` | optional *string literal* or *path* | The name of the XML attribute to match. If it is a *path*, it must point at a `&'static NcNameStr`. |
| `default` | *flag* | If present, an absent attribute will substitute the default value instead of raising an error. |
| `type_` | *type* | Optional explicit type specification. Only allowed within `#[xml(extract(fields(..)))]`. |
+| `codec` | optional *expression* | [`TextCodec`] implementation which is used to encode or decode the field. |
If the `name` key contains a namespace prefix, it must be one of the prefixes
defined as built-in in the XML specifications. That prefix will then be
@@ -284,6 +285,9 @@ If `type_` is specified and the `text` meta is used within an
`#[xml(extract(fields(..)))]` meta, the specified type is used instead of the
field type on which the `extract` is declared.
+If `codec` is given, the given `codec` value must implement
+[`TextCodec<T>`][`TextCodec`] where `T` is the type of the field.
+
#### Example
```rust