Ionic 2 couchdb pouchdb : how to get data which is not synced yet

Ionic Framework ionic-v3
1

i have a feeling that issue i am having facing is some stupid simple basic thing but i m still not able to figure it out.

I have having couchdb server which have thousands of documents. which are categories as type:topics and type:quiz. basically topic documents contains list of quiz documents ids and the type quiz documents contain the question and answer

Sample : topic document

{
   "_id": "topic-57913023930b4",
   "_rev": "1-1b8968c43bacffa849fab9bc62fbe910",
   "name": "Programming Languages",
   "type": "topic",
   "pid": "topic-57913023930b4",
   "totalQuiz": 19,
   "quiz": [
       {
           "id": "quiz-5790b7035f496"
       },
       {
           "id": "quiz-5790b7fbacc8e"
       },
       {
           "id": "quiz-5790b3291766d"
       },
       {
           "id": "quiz-5790afc077f64"
       }

   ]
}

sample: quiz document

{
   "_id": "quiz-5790a476e184c",
   "_rev": "1-48acc3b900b6010cf3d527fcf26f8e0c",
   "question": "this is a question",
   "correctanswer": 0,
   "answers": [
       "option 1",
       "option 2",
       "option 3",
       "option 4"
   ]  
}

Now to sync the server database to the local database .if i sync whole database then my local database like this :

this.db = new PouchDB('mydb');   
 this.remote ='http://IP_ADDRESS:5984/mydb';
 let options = {
      live: true,
      retry: true,
      continuous: true      
    };
 this.db.sync(this.remote, options);

then my local database will get huge in just few minutes because my server contains thousands of documents. i wish to avoid that and download documents only on demand. i am not sure how to do that

if i use some basic filter to pull only the documents that are of type : topics at the start like this :

this.db = new PouchDB('mydb');   
 this.remote ='http://IP_ADDRESS:5984/mydb';
    let options = {
      live: true,
      retry: true,
      continuous: true,
      filter:  function (doc) {
                return doc.type === 'topic';
              }
    };
    this.db.sync(this.remote, options);

if i do above then only topics documents get pulled but i dont have access to the quiz documents at all. perhaps i need to disable syncing and figure out a way to download data only on demand. not sure how to do that though :frowning:

But anyway even i let the whole database gets synced automatically in the constructor. still it takes along time to replicate the database to the local database .

lets say in the home page of the app i want to display a topic ‘Programming Languages’ from the document id : “_id”: “topic-57913023930b4” . for that i made this code

ionViewLoaded(){     
     this.DataService.getDocument('topic-57913023930b4').then((result) => {
        this.data = result;
       }); 
}

and in my service i have this code:

getDocument(id) {      
          return new Promise(resolve => {         
            this.db.get(id).then((result) =>{                    
              this.data=result;          
              resolve(this.data);                 
            }).catch((error) => {   
              console.log(error);   
            });       
          });
    }

But when the app starts it hasnt pulled all those thousand documents yet so my local database dont have document with id ‘topic-57913023930b4’ . it might take several minutes to get that document if i rely on the constructor’s data sync code.

so i need a way to pull this data from the couchdb server at this very moment. but i m not sure how to do that. although i know can use HTTP request but it wont get synced with the pouchdb local database.

Please guide me in the right direction. i have been trying to make this working since yesterday but not able to figure this out.