Storing & querying nested resources

[atomicdata-dev]

Storing & querying nested resources

[joepio]

Perhaps it makes sense to start with the atomic_lib::Resource API - which does not support nested resources yet.

I think something like this makes sense:

let resource = Resource::new();
let nested_resource  = resource.new_nested("https://example.com/someProp");
nested_resource.set_prop_shortname("description", "me is nested");

With this API, the nested_resource needs some reference to the store, just like the Resource does (otherwise, changing props would not do anything).

A different approach, where we set a nested resource as a value:

let resource = Resource::new();
let nested_resource  = resource.new_nested();
nested_resource.set_prop_shortname("description", "me is nested");
resource.set("https://example.com/someProp", nested_resource);

Now, let's consider a case where theres a 1-N relationship, instead of a 1-1. Perhaps we've got a Blog with some posts.
How should we append a blogpost to our blog, assuming it's a nested resource?

let blog = Resource::new();
let post  = blog.new_nested();
post.set_prop_shortname("text", "I'm a blogpost!");
blog.set_prop_shortname("posts", Vec::from(blog.get("posts")).push(post));

Yuck... Perhaps we need some functions to deal with array (of nested resources):

let blog = Resource::new();
let post  = blog.new_nested();
let postslist = blog.get_as_vec("posts");
postslist.push(post);
// Maybe we won't need this following one, if the get_as_vec is awayre
let blog.post = postslist;

[joepio]

For now, I think I'm going to try storing Values instead of Strings in the store. This means refactoring quite a bit of code.

[joepio]

Currently, nested resources (at least in the Commit.rs impl) are serialized using Hashmap's auto conversion... Not nice.

This needs more thought. I think the AtomicURL datatype should be removed, and should be replaced by a Resource datatype, which can be either a URL or a Nested Resource.

The Nested Resource should be serialized as a JSON object in JSON, and perhaps in some other way in AD3.

[joepio]

Should I allow both Nested and URL resources in an array?

/// An individual Value in an Atom, represented as a native Rust enum.
#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum Value {
    AtomicUrl(String),
    Date(String),
    Integer(isize),
    Markdown(String),
    ResourceArray(Vec<ResourceValue>),
    Slug(String),
    String(String),
    /// Unix Epoch datetime in milliseconds
    Timestamp(i64),
    NestedResource(PropVals),
    Boolean(bool),
    Unsupported(UnsupportedValue),
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum ResourceValue {
    NestedResource(PropVals),
    AtomicUrl(String),
}