Hotfix: Expose import media types through wasm bindings (#595)

Nemo Web was not able to set correct accept headers for resources loaded
from e.g. sparql queries since the type of the resource was not exposed
through the wasm bindings. This PR changes this. There is a
corresponding PR in Nemo Web making use of this.

Author: monsterkrampe

nemo-wasm/src/lib.rs

@@ -68,6 +68,23 @@ impl NemoError {
     }
 }
 
+#[wasm_bindgen]
+pub struct NemoResource {
+    accept: String,
+    url: String,
+}
+
+#[wasm_bindgen]
+impl NemoResource {
+    pub fn accept(&self) -> String {
+        self.accept.clone()
+    }
+
+    pub fn url(&self) -> String {
+        self.url.clone()
+    }
+}
+
 #[wasm_bindgen]
 impl NemoProgram {
     #[wasm_bindgen(constructor)]
@@ -95,16 +112,20 @@ impl NemoProgram {
     /// just make sure that things validate upon creation, and make sure that problems
     /// are detected early.
     #[wasm_bindgen(js_name = "getResourcesUsedInImports")]
-    pub fn resources_used_in_imports(&self) -> Set {
-        let js_set = Set::new(&JsValue::undefined());
+    pub fn resources_used_in_imports(&self) -> Vec<NemoResource> {
+        let mut result: Vec<NemoResource> = vec![];
 
         for directive in self.0.imports() {
+            let format = directive.file_format().media_type();
             if let Some(resource) = directive.attributes().get(&ImportExportAttribute::Resource) {
-                js_set.add(&JsValue::from(resource.to_string()));
+                result.push(NemoResource {
+                    accept: format.to_string(),
+                    url: resource.to_string(),
+                });
             }
         }
 
-        js_set
+        result
     }
 
     // If there are no outputs, marks all predicates as outputs.