Resources

I've decided to tackle Resources before tackling id and extension because there are common features between Elements and Resources. This is somewhat confusing: The Resource type is described as having no base type, but like the Element, has a name and a set of values (defined by the Resource base content, and the respective Resource definition and profile). The Resource has an id and the DomainResource also has a set of extensions. In addition, each Resource has a set of sub-elements, some of which are incorporated from the Resource and DomainResource model, and some of which are defined by the individual resource domain models and profiles.

In accordance with my basic philosophy of "do the simplest thing that could possibly work", the easiest definition for Resource is the following:

pub struct Resource {
    pub name: String,
    pub elts: Vec<Element>
}

Unlike the Element case, we can handle id and extension as regular elements (although Extensions are a bit strange, as we'll see when we get to them). We'll see why when we get to them.

Given this definition, serializing is pretty trivial:

impl ToJson for Resource {
    fn to_json(&self) -> Json {
        let mut o: BTreeMap<String,Json> = BTreeMap::new();
        o.insert("resourceType".to_string(),Json::String(self.name.clone()));
        for e in self.elts.iter() {
            o.insert(e.name.clone(), e.value.to_json());
        }
        Json::Object(o)
    }
}

There's a resourceType name value pair which holds the name of the Resource, and then we just serialize each sub-element according to the serialization rules we previously defined.

And that's kinda it.

Next up, id and extension at the Element level, and we'll have fully functional JSON serialization.