IOS Swift - Get values from different nodes in Firebase database -


i'd list of participants of event, in events node, id# of employee listed. achieve name associated id # employee node. here's structure of dbase.

events:      uuid:         name: summer festival 2017         site: vegas         participants:            employeeid1: true            employeeid2: true   employee:     employeeid1:        name: gary        department: video production

and here's code

@ibaction func downloadbuttonaction(_ sender: uibutton) {        ref.child("events").child(eventkeylabel.text!).child("participants").observesingleevent(of: .value, with: {(snapshot) in              // dictionary snapshot             if let participantsdict = snapshot.value as? [string : anyobject] {                   each in participantsdict {                      let employeeidnum = each.key                     let employeename = self.getname(foruid: employeeidnum)                      self.employeeid.append(employeeidnum)                     self.name.append(employeename)                  }                print(self.employeeid)               print(self.name)              }          }) // end observesingleevent      }       func getname(foruid userid: string) -> string{          var empname = ""          ref.child("employee").child(userid).observe(dataeventtype.value, with: { (snapshot) in             if let value = snapshot.value as? nsdictionary {                  empname = (value["name"] as? string)!             }         })         return empname     }

results:

["0001", "0002", "0003", "0004"] ["", "", "", ""]

full code:

@ibaction func downloadbuttonaction(_ sender: uibutton) {

ref.child("events").child(eventkeylabel.text!).child("participants").observesingleevent(of: .value, with: {(snapshot) in      // dictionary snapshot     if let participantsdict = snapshot.value as? [string : anyobject] {           each in participantsdict {              let employeeidnum = each.key             self.getname(foruid: employeeidnum) { empname in                 self.name.append(empname)                 print(empname)             }              self.employeeid.append(employeeidnum)           }          print(self.employeeid)         print(self.name)      }  }) // end observesingleevent

}

func getname(foruid userid: string, callback: @escaping (string)->void){

ref.child("employee").child(userid).observe(dataeventtype.value, with: { (snapshot) in     if let value = snapshot.value as? nsdictionary {         print(value)         if let empname = value["name"] as? string{             callback(empname)         }     } })

}

it doesn't return employee names. please help. thank you!

problem since fetching firebase asynchronous call, have use callback name function calling getname method, can this:

@ibaction func downloadbuttonaction(_ sender: uibutton) {        ref.child("events").child(eventkeylabel.text!).child("participants").observesingleevent(of: .value, with: {(snapshot) in              // dictionary snapshot             if let participantsdict = snapshot.value as? [string : anyobject] {                   each in participantsdict {                      let employeeidnum = each.key                     self.getname(foruid: employeeidnum)                      self.employeeid.append(employeeidnum)                   }                print(self.employeeid)               print(self.name)              }          }) // end observesingleevent      }       func getname(foruid userid: string) {            ref.child("employee").child(userid).observe(dataeventtype.value, with: { (snapshot) in             if let value = snapshot.value as? nsdictionary {                 print(value) //add here                 if let empname = value["name"] as? string{                        self.name.append(empname)                  }             }         })       }

Comments

Post a Comment

Popular posts from this blog

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

i'm implementing inapp billing in android app. works well, however, i'm trying decouple broadcast receiver activity manifest. suggestion in android's trivialdrive sample: // important: dynamically register broadcast messages updated purchases. // register receiver here instead of <receiver> in manifest // because call getpurchases() @ startup, therefore can ignore // broadcasts sent while app isn't running. // note: registering listener in activity bad idea, done here // because sample. regardless, receiver must registered after // iabhelper setup, before first call getpurchases(). currently there's class extends broadcastreceiver : public class iabbroadcastreceiver extends broadcastreceiver { /** * intent action receiver should filter for. */ public static final string action = "com.android.vending.billing.purchases_updated"; private final iabbroadcastlistener mlistener; public iabbroadcastreceiver(iabbroadcastlistener listener) { m...
Read more

python Tkinter Capturing keyboard events save as one single string -

is possible store keyboard events 1 string? code below stores 1 char , prints it. card reader or bar code reader, contains collection of character/ string not 1 character @ time. goal save char pressed text variable. from tkinter import * root = tk() def key(event): text= event.char text+= event.char print ("pressed", text) def callback(event): frame.focus_set() print ("clicked at", event.x, event.y) frame = frame(root, width=100, height=100) frame.bind("<key>", key) frame.bind("<button-1>", callback) frame.pack() root.mainloop() currently, creating text variable , everytime key() function gets called, , text stores last character typed. you can define text module level variable , , use module level text inside key function - text = '' def key(event): global text text+= event.char print("pressed", text)
Read more

sql server - Why does Linq-to-SQL add unnecessary COUNT()? -

here tables: create table customer ( cid int primary key, name varchar(32) ) create table ord ( oid int primary key, cid int foreign key references customer, address varchar(20) ) here's linq-to-sql statement: var aaa = c in db.customer select new { c, o = c.ord.tolist() }; and here's inexplicable query generated linq-to-sql: select [t0].[cid] [cid], [t0].[name] [name], [t1].[oid] [oid], [t1].[cid] [cid2], [t1].[address] [address], (select count(*) [dbo].[ord] [t2] [t2].[cid] = [t0].[cid]) [value] [dbo].[customer] [t0] left outer join [dbo].[ord] [t1] on [t1].[cid] = [t0].[cid] order [t0].[cid], [t1].[oid] i want understand how rid of count(*) part. it's entirely uncalled for! linq needs count(*) in order determine number of entries returned o = c.ord.tolist() .
Read more