diff options
Diffstat (limited to '')
| -rw-r--r-- | askama_derive/src/input.rs | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/askama_derive/src/input.rs b/askama_derive/src/input.rs index ce004a8..15a4a6d 100644 --- a/askama_derive/src/input.rs +++ b/askama_derive/src/input.rs @@ -19,7 +19,13 @@ pub struct TemplateInput<'a> { } impl<'a> TemplateInput<'a> { + /// Extract the template metadata from the `DeriveInput` structure. This + /// mostly recovers the data for the `TemplateInput` fields from the + /// `template()` attribute list fields; it also finds the of the `_parent` + /// field, if any. pub fn new(ast: &'a syn::DeriveInput) -> TemplateInput<'a> { + // Check that an attribute called `template()` exists and that it is + // the proper type (list). let mut meta = None; for attr in &ast.attrs { match attr.interpret_meta() { @@ -39,6 +45,9 @@ impl<'a> TemplateInput<'a> { _ => panic!("attribute 'template' has incorrect type"), }; + // Loop over the meta attributes and find everything that we + // understand. Raise panics if something is not right. + // `source` contains an enum that can represent `path` or `source`. let mut source = None; let mut print = Print::None; let mut escaping = None; @@ -84,6 +93,9 @@ impl<'a> TemplateInput<'a> { } } + // Validate the `source` and `ext` value together, since they are + // related. In case `source` was used instead of `path`, the value + // of `ext` is merged into a synthetic `path` value here. let source = source.expect("template path or source not found in attributes"); let path = match (&source, &ext) { (&Source::Path(ref path), None) => path::find_template_from_path(path, None), @@ -96,6 +108,8 @@ impl<'a> TemplateInput<'a> { } }; + // Check to see if a `_parent` field was defined on the context + // struct, and store the type for it for use in the code generator. let parent = match ast.data { syn::Data::Struct(syn::DataStruct { fields: syn::Fields::Named(ref fields), |