java - Google IO 2010 Virgil Dobjanschi pattern C example -

i have tried virgil dobjanschi patterns , b , made conclusion want use pattern c because in case can use google based code take care how may data device if have non-stable network connection , on... didn't find how implement in right way. when consider database large enough syncing every time.

i did this

when cursorloader did query show bizinbox query returned cursor , started syncadapter should data , stop activity

but problem syncadatert's onperformsync start agin , again. , looks endless cycle when cursor reload data , start onperformsync , on... , syncadapter in parallel without queue hoped.

i should notice rest end process data correctly , second request onperformsync have no data because used if-modified-since http header.

it did wrong, becuase syncadapter did not sync backoff , did requests without end.

when did if (!contentresolver.issyncactive(mconnectedaccount, scheme.authority)) { contentresolver.requestsync( mconnectedaccount, // sync account scheme.authority, // content authority b); // extras } else { log.d(tag, "> runsyncadaterforclaimbizinbox skip starting adapter active"); }

i able win problem question remained how perform syncing if need sync part of data - not data contentresolver.issyncactive(mconnectedaccount, scheme.authority) - method can not give info part of data syncing , don't have queue reasons here. how manage problem ?

please, me find errors or may has pattern c compilable code find out how implement pattern right.

thanks in advance.

the code below:

public class contentprovider {

 @override  public cursor query(final uri uri, final string[] projection, final string selection, final string[] selectionargs, final string sortorder) {       final sqlitequerybuilder qb = new sqlitequerybuilder();      final string orderby = preparequery(uri, sortorder, qb);       final sqlitedatabase db = databasehelper.getreadabledatabase();      final cursor cursor = qb.query(db, projection, selection, selectionargs, null, null, orderby);       runsyncadapterforquery(uri);       cursor.setnotificationuri(getcontext().getcontentresolver(), uri);       return cursor;  }  void runsyncadapterforquery(uri uri) {     switch (urimatcher.match(uri)) {         case biz_inbox:             runsyncadaterforbizinbox(method_get);             break;     } }  void runsyncadaterforbizinbox(string method) {      bundle b = new bundle();      b.putboolean(contentresolver.sync_extras_manual, true);     b.putboolean(contentresolver.sync_extras_expedited, true);      b.putstring(method_extra, method);     b.putint(resource_type_extra, resource_type_biz_inbox);      account mconnectedaccount = new account(bpalaccountgeneral.account_name, bpalaccountgeneral.account_type);    //if (!contentresolver.issyncactive(mconnectedaccount, scheme.authority)) { need ? sync adapters queue ?      contentresolver.requestsync(             mconnectedaccount, // sync account             scheme.authority, // content authority             b);               // extras    //} } 

}

syncadapter  @override public void onperformsync(account account, bundle extras, string authority, contentproviderclient provider, syncresult syncresult) {       string accesstoken = "some_token";      switch (resourcetype) {         case unknown_resource_type:             //do update ...             break;         case resource_type_biz_inbox:             if (method.equals(method_get)) {                  string url = "some_inbox_url"                  getbizinboxrequest request = new getbizinboxrequest();                  bizinboxdao bizinboxdao = new bizinboxdao();                 string lastmodified = bizinboxdao.getlastmodified(getcontext().getcontentresolver());                  restmethodresult<restlistentitycontainer<bizinboxentity>> restmethodresult =                         request.getbizinboxitems(                                 url,                                 null,                                 lastmodified,                                 accesstoken);                  int statuscode = restmethodresult.getstatuscode();                  if (statuscode == mobileconstant.http_ok) {                     list<bizinboxentity> serverbizinboxentities = restmethodresult.getresource().getlist();                      (bizinboxentity entity : serverbizinboxentities) {                         bizinboxdao.insertydata(getcontext().getcontentresolver(), entity);                         syncresult.stats.numinserts++;                     }                      if(syncresult.stats.numinserts > 0) {                         log.d(tag, "> onperformsync  bizinboxdao.sendnotification ");                         bizinboxdao.sendnotification(getcontext().getcontentresolver());                     }                 } else {                     syncresult.stats.numioexceptions++;                     syncresult.databaseerror = true;                 }             }             break;         default:             break;     } } 

i did big mistake using code above.

1. according pattern c sync adapter should check current data state. shouldn't call request sync directly content provider. ways able use described in android docs https://developer.android.com/training/sync-adapters/running-sync-adapter.html

2. if called syncing below // disable sync backoff , ignore sync preferences. in other words...perform sync now! b.putboolean(contentresolver.sync_extras_manual, true); b.putboolean(contentresolver.sync_extras_expedited, true);

   account mconnectedaccount = new account(accountgeneral.account_name, accountgeneral.account_type);      contentresolver.requestsync(             mconnectedaccount, // sync account             scheme.authority, // content authority             b);               // extras 

you should remember put comments:
disable sync backoff , ignore sync preferences. in other words...perform sync now!

it means request not try repeat if failed. , code run action in parallel. example if run requestsync 2 tiles have 2 syncing threads found.

and last main note: when run requestsync query caused endless cycle, because after requestsync cursot notifing call re-query run requestsync again , etc...

3. i found example app used pattern c - link: https://github.com/taoliuh/v2ex