Pagination in firestore api

Question

I am trying to paginate documents with firestore beta. I am following the official docs

I see there is a pageSize param to say how many documents you want to show, b

Answer 1

This may help paginating without page numbers (previous and next):

app.get('/page/next/:startAt',(req, res)=>{
      (async ()=>{
          try{
              const startAt = req.params.startAt;
              let query = db.collection('movies');
              let response = [];
              console.log(query);
              await query.orderBy('time', 'desc').where("time", "<", new Date(parseInt(startAt)*1000)).limit(16).get().then(snapshots => {
                let docs = snapshots.docs;

                for (let doc of docs){
                    console.log(doc.data());
                    const selectedItems = {
                        id: doc.id,
                        name: doc.data().name,
                        desp: doc.data().desp,
                        site: doc.data().site,
                        time: doc.data().time
                    }
                    response.push(selectedItems);
                }
                  return response;  //each then should return a vlue
              })
              return res.status(200).send(response);
          }catch (error){
              console.log(error);
              return res.status(500).send(error);
          }
      })();
    });


    app.get('/page/back/:backAt',(req, res)=>{
      (async ()=>{
          try{
              const backAt = req.params.backAt;
              let query = db.collection('movies');
              let response = [];
              console.log(query);
              await query.orderBy('time', 'desc').where("time", ">", new Date(parseInt(backAt)*1000)).limit(16).get().then(snapshots => {
                let docs = snapshots.docs;

                for (let doc of docs){
                    console.log(doc.data());
                    const selectedItems = {
                        id: doc.id,
                        name: doc.data().name,
                        desp: doc.data().desp,
                        site: doc.data().site,
                        time: doc.data().time
                    }
                    response.push(selectedItems);
                }
                  return response;  //each then should return a vlue
              })
              return res.status(200).send(response);
          }catch (error){
              console.log(error);
              return res.status(500).send(error);
          }
      })();
    });