Update

src/client/api.ts

@@ -41,8 +41,9 @@ export const load = (id: string) =>
             return res;
         });
 
-export const save = (id: string, v: journey) =>
-    fetch("/api/" + id, { method: "post", body: JSON.stringify(v) })
+export const save = async (id: string, v: journey) => {
+    v.version +=1;
+    return fetch("/api/" + id, { method: "post", body: JSON.stringify(v) })
         .then((res) => {
             if (!res.ok) throw new Error("Error " + res.statusText);
             return res.json();
@@ -50,6 +51,7 @@ export const save = (id: string, v: journey) =>
         .then((_res) => {
             console.log("Saved...");
         });
+    }
 
 export const query_nominatim = (
     q: string,

src/client/types/format.ts

@@ -35,6 +35,7 @@ declare global {
 
     interface journey {
         fmt_ver: number
+        version: number
         title: string
         main: leg[]
     }
@@ -52,6 +53,7 @@ const leg_template: leg = {
 }
 const journey_template: journey = {
     fmt_ver: 1,
+    version: 0,
     title: "New Journey",
     main: [leg_template],
 }

src/client/types/migration.ts

@@ -10,6 +10,7 @@ function migrate_A_to_0(e: journey): journey {
         v.travel = v.travel || [];
         v.day_title = typeof (v.day_title) == "string" ? [v.day_title] : []
     })
+    e.version = e.version || 0;
     console.log(e)
     return e;
 }

src/server/api.ts

@@ -75,16 +75,15 @@ export default function (server, opts, done) {
     if (req.params.id == undefined)
       return reply.code(400).send({ error: "No ID query parameter" });
 
-    server.level.db.put(req.params.id, req.body, (err) => {
-      if (err) {
-        console.warn(err);
-        reply.code(500).send({ error: "Error with DB" });
-      } else {
-        reply.send({ content: "ok" });
-      }
-    });
-    return reply;
-  });
+    return server.level.db.get(req.params.id).then(r=>r.version||-1).catch(_=>-1).then(db_version=>{
+      if(db_version+1 == req.body.version)
+        return server.level.db.put(req.params.id, req.body)
+          .then(_=>reply.send({ content: "ok" }))
+          .catch(_=>reply.code(500).send({ error: "Error with DB" }))
+        
+      return reply.code(409).send({error:"Too old version, please refresh."});
+      })
+  })
 
   done();
 };