more admin dashboard polish, some code cleanup

admin/static/artists.js

@@ -4,4 +4,29 @@ document.addEventListener("readystatechange", () => {
     document.querySelectorAll(".artists-group .artist").forEach(el => {
         hijackClickEvent(el, el.querySelector("a.artist-name"))
     });
+
+    const newArtistBtn = document.getElementById("create-artist");
+    if (newArtistBtn) newArtistBtn.addEventListener("click", event => {
+        event.preventDefault();
+        const id = prompt("Enter an ID for this artist:");
+        if (id == null || id == "") return;
+
+        fetch("/api/v1/artist", {
+            method: "POST",
+            headers: { "Content-Type": "application/json" },
+            body: JSON.stringify({id})
+        }).then(res => {
+            res.text().then(text => {
+                if (res.ok) {
+                    location = "/admin/artists/" + id;
+                } else {
+                    alert(text);
+                    console.error(text);
+                }
+            })
+        }).catch(err => {
+            alert("Failed to create artist. Check the console for details.");
+            console.error(err);
+        });
+    });
 });