I'm working on a android messagerie app, messages are stored in a CouchDB(Apache) database on the internet. How can I pull messages with filter on my Android devices?
Android Snippet:
Replication pull = new Replication(messageDB, messageUrl, Replication.Direction.PULL);
//filter
pull.setFilter("message/by_username");
HashMap<String, Object> filterParams = new HashMap<>();
filterParams.put("username", usr);
pull.setFilterParams(filterParams);
pull.setContinuous(false); //oneshot
pull.start();
Apache design document:
{
"_id": "_design/message",
"views": {
"by_username": {
"map": "function (doc) {\n emit([doc.username]);\n \n}"
}
},
"filters": {
"by_username": "function(doc, req){ if(!doc.username) return false; if(req.query.username && req.query.username != doc.username){return false} else {return true}}"
},
"language": "javascript"
}
With the block filter, the synchronization will never stop but the database is always empty (I did not find any document after 3 minutes).
Without the block filter, all messages are downloaded in only few seconds. Thanks.
There is however a workaround for working with couchbase lite 1.4 with couchdb 2.x server to working without any change in the library as mentioned above. Please refer to answer given here
Source :
https://developer.couchbase.com/documentation/mobile/current/guides/couchbase-lite/native-api/replication/index.html#filtered-pull-from-couchdb-pouchdb-or-cloudant
Filtered pull from CouchDB, PouchDB or Cloudant
Since Couchbase Lite 1.2, filter functions in pull replications with non-Couchbase databases are no longer available. There is an incompatibility in the way the filter parameter is handled in the POST /{db}/_changes request (see #1139).