feat(connections): browse and add datasets from the Connections tree

crates/engine/src/cmd/connections.rs

@@ -10,6 +10,9 @@ use crate::connections::{Connection, DATABASE_KINDS, DESKTOP_ONLY, KINDS};
 use crate::render::rustgis_tiles::{s3, stac};
 use crate::{CmdResult, CommandSpec as C, Session};
 
+#[path = "connection_browse.rs"]
+mod browse;
+
 pub fn commands() -> Vec<C> {
     vec![
         C::new("connection.list", "List Connections", "Home › Add › Data Sources", list).view().params(
@@ -29,6 +32,9 @@ pub fn commands() -> Vec<C> {
         C::new("connection.test", "Test Connection", "Home › Add › Data Sources", test).view().params(
             r#"{"id"?: "a connection's id or name", "kind"?: "postgres"|"mysql"|"sqlserver"|"service"|"wms"|"wmts"|"wfs"|"wcs"|"ogcapi"|"arcgis"|"csw"|"stac"|"s3", "name"?: text, "group"?: text, "address"?: text, "options"?: "an unsaved connection, as connection.new (when no id)", "password"?: text, "accessKeyId"?: text, "secretAccessKey"?: text, "sessionToken"?: "as connection.login (logs in first)", "probe"?: "true: only the address the test reads, {fetch} (null for databases, which their driver tests)", "answer"?: "non-database kinds only: what that address returned, when the app fetched it (no network request then); databases ignore answer and test through their driver"}"#,
         ),
+        C::new("connection.browse", "Browse Connection", "Home › Add › Data Sources", browse::browse).view().params(
+            r#"{"id": "a connection's id or name", "node"?: "a child's node, as a listing gives it (the connection's top level when absent)", "probe"?: "true: only the address this level reads, {fetch} (null: read without a fetch, or by the database driver); an S3 connection logs in first, as connection.test does", "answer"?: "what that address returned, when the app fetched it", "documents"?: [{"url": "a further document a listing asked for (next)", "text": "its answer"}]} → {connection, node, children: [{key, name, what, detail?, node? (browse it), children? (listed already), add? {command, params}: the command that adds it}], truncated?, matched?, notes?, service? {url, type}, next? (fetch it, then ask again with answer and documents)}"#,
+        ),
     ]
 }
 
@@ -53,16 +59,7 @@ fn shown(c: &Connection) -> Value {
     } else {
         false
     };
-    let add_with = match c.kind.as_str() {
-        "postgres" | "mysql" | "sqlserver" => "info.databaseTables {database: address}, then layer.addDatabase {database: address, layer}",
-        "service" => "service.layers {url: address}, then service.add {url, layer}",
-        "wms" | "wmts" | "wfs" | "ogcapi" | "arcgis" => "service.layers {url: address, type: kind}, then service.add {url, type, layer}",
-        "wcs" => "service.layers {url: address, type: wcs}, then service.coverage {url, layer}",
-        "csw" => "catalog.search {url: address, query}",
-        "stac" => "stac.collections {url: address}, then stac.search {url, collections}",
-        "s3" => "connection.login {id} once, then s3.list {connection: name}, then layer.addUrl {url: s3://…}",
-        _ => "",
-    };
+    let add_with = "connection.browse {id}, then {id, node} for a child's node; run a dataset's add {command, params}";
     let mut out = serde_json::to_value(c).unwrap_or(Value::Null);
     out["available"] = json!(available);
     if !available {

crates/engine/src/cmd/layer.rs

@@ -1280,6 +1280,15 @@ pub(super) fn database_tables(_s: &mut Session, p: &Value) -> CmdResult {
     }
 }
 
+/// The geometry tables of a live database server, with the schema, name, column and type of
+/// each (`connection.browse` groups them by schema).
+#[cfg(not(target_arch = "wasm32"))]
+pub(super) fn database_table_details(p: &Value) -> Result<Vec<Value>, String> {
+    let db = database_param(p).ok_or("database is required")?;
+    let live = LiveDb::connect(&db).ok_or("not a database server")?.map_err(|e| format!("{}: {e}", db.short()))?;
+    Ok(live.tables().map_err(|e| format!("{}: {e}", db.short()))?.iter().map(LiveTable::detail).collect())
+}
+
 /// Adds the tables of a database (a PostgreSQL connection or a DuckDB file) that have a geometry
 /// column, or the one `layer` names.
 fn add_database(s: &mut Session, p: &Value) -> CmdResult {
@@ -1399,6 +1408,16 @@ impl LiveTable {
             LiveTable::Sqlserver(t) => t.label(),
         }
     }
+
+    /// The table as a browser lists it: its label for `layer.addDatabase`, and what it is made of.
+    fn detail(&self) -> Value {
+        let (schema, name, column, kind) = match self {
+            LiveTable::Postgis(t) => (&t.schema, &t.name, &t.column, &t.kind),
+            LiveTable::Mysql(t) => (&t.schema, &t.name, &t.column, &t.kind),
+            LiveTable::Sqlserver(t) => (&t.schema, &t.name, &t.column, &t.kind),
+        };
+        json!({"label": self.label(), "schema": schema, "name": name, "column": column, "kind": kind})
+    }
 }
 
 #[cfg(not(target_arch = "wasm32"))]

crates/engine/src/cmd/plugins.rs

@@ -276,6 +276,7 @@ const NEVER: &[&str] = &[
     "connection.remove",
     "connection.login",
     "connection.test",
+    "connection.browse",
     "s3.connect",
     "s3.disconnect",
     "earthdata.login",