Hosts

A host implements resolve, owns session, navigation, and layout, and calls the runtime. Views know nothing about which host runs them.

flowchart TB
  subgraph lib [library]
    R[renderer]
    RT[DOM runtime]
    V1[Markdown view]
    V2[container view]
    V3[fallback view]
  end
  B[browser shell<br/>resolve = fetch with session] --> RT
  S[server-side converter<br/>resolve = the server's own store] -.-> R
  W[WASM view adapter<br/>resolve as an async import] -.-> V1
  RT --> R
  R --> V1 & V2 & V3

Solid lines exist today; dotted ones are the adapters the contract is cut for.

The browser shell

A single HTML page with one bundle. A Community Solid Server serves it as the text/html representation of every resource, including on a 401, so the page loads at the resource’s own URL and the address bar is the resource.

sequenceDiagram
  participant P as person
  participant Sh as shell
  participant CSS as pod
  P->>CSS: GET /notes/a.md (Accept: text/html)
  CSS-->>P: 200 or 401, body = the shell
  Sh->>Sh: restore Solid-OIDC session
  Sh->>CSS: GET /notes/a.md (Accept: text/markdown, text/turtle, …)
  alt 401 and no session
    Sh->>P: log-in control
    P->>CSS: Solid-OIDC login, redirect back
  else 200
    CSS-->>Sh: representation + headers
    Sh->>Sh: Resource from body, Content-Type, Link rel=type, Last-Modified, WAC-Allow
    Sh->>Sh: runtime.mount(root, iri, hint)
  end

The fetch is a second request for the same resource. The slot that serves the shell is a constant document, so it cannot carry the representation along; a server-side host removes that round trip.

Navigation

The shell listens for as:View. Another resource is a fresh mount into the region; the same resource with a new fragment is a dispatch and no refetch. The address follows either, and popstate runs the same two branches in reverse. A view query parameter on the URL becomes hint.view, the hash becomes hint.fragment.

Server-side host

A representation converter inside the pod server calling the same renderer. Rendered.html is all it needs. It can embed the representation in the document it serves, so a shell hydrates without a second request.

WASM views

A view implemented as a WebAssembly component: resolve as an async import, render as an export, wrapped by an adapter that implements View. Interactivity through an event stream in and patches out, which is what Handle.update already is. Nothing in Resource has a prototype, which is what lets it cross that boundary as data.