duster/src/renderer/renderer.rs

90 lines
3.3 KiB
Rust

use crate::parser::template;
use crate::parser::Path;
use crate::parser::Template;
use crate::renderer::breadcrumb_tree::BreadcrumbTree;
use crate::renderer::breadcrumb_tree::BreadcrumbTreeElement;
use crate::renderer::context_element::ContextElement;
use crate::renderer::context_element::IntoContextElement;
use crate::renderer::errors::CompileError;
use crate::renderer::tree_walking::walk_path;
use std::collections::HashMap;
#[derive(Clone, Debug)]
pub struct DustRenderer<'a> {
templates: HashMap<String, &'a Template<'a>>,
}
pub fn compile_template<'a>(source: &'a str) -> Result<Template<'a>, CompileError> {
let (_remaining, parsed_template) = template(source).map_err(|err| CompileError {
message: "Failed to compile template".to_owned(),
})?;
Ok(parsed_template)
}
impl<'a> DustRenderer<'a> {
pub fn new() -> DustRenderer<'a> {
DustRenderer {
templates: HashMap::new(),
}
}
pub fn load_source(&mut self, template: &'a Template, name: String) {
self.templates.insert(name, template);
}
/// Returns a option of a tuple of (parent, new_node_elements)
/// which can then be formed into new BreadcrumbTreeNodes
///
/// If None is returned, then it is a signal to simply re-use the
/// existing breadcrumbs.
///
/// Otherwise, the parent (which may be None, especially for
/// explicit contexts) and the additional node elements (which may
/// be empty) should be combined into a final BreadcrumbTreeNode
fn new_breadcrumbs_section<'b>(
&self,
maybe_breadcrumbs: Option<&'a BreadcrumbTree>,
index_context: Option<&'b dyn IntoContextElement>,
injected_context: Option<&'b dyn IntoContextElement>,
explicit_context: &Option<Path<'b>>,
new_context_element: Option<&'b dyn ContextElement>,
) -> Option<(Option<&'b BreadcrumbTree>, Vec<BreadcrumbTreeElement<'b>>)> {
// If none of the additional contexts are present, return None
// to signal that the original breadcrumbs should be used
// rather than incurring a copy here.
match (
index_context,
injected_context,
explicit_context,
new_context_element,
) {
(None, None, None, None) => return None,
_ => (),
}
// If there is an explicit context, then drop all the current
// context
let mut parent = match explicit_context {
Some(_) => None,
None => maybe_breadcrumbs,
};
let mut new_nodes: Vec<BreadcrumbTreeElement> = Vec::new();
explicit_context.as_ref().map(|path| {
let x = walk_path(maybe_breadcrumbs, &path.keys);
x.map(|ice| ice.into_context_element(self, maybe_breadcrumbs))
.map(|val| {
if val.is_truthy() {
new_nodes.push(BreadcrumbTreeElement::Borrowed(val.from_context_element()))
}
});
});
injected_context.map(|ctx| new_nodes.push(BreadcrumbTreeElement::Borrowed(ctx)));
new_context_element
.map(|ctx| new_nodes.push(BreadcrumbTreeElement::Borrowed(ctx.from_context_element())));
index_context.map(|ctx| new_nodes.push(BreadcrumbTreeElement::Borrowed(ctx)));
Some((parent, new_nodes))
}
}