update with some better practise syntax

Author: sadief

contracts/AllDay.cdc

@@ -131,10 +131,13 @@ pub contract AllDay: NonFungibleToken {
         // initializer
         //
         init (id: UInt64) {
-            let series = (&AllDay.seriesByID[id] as &AllDay.Series?)!
-            self.id = series.id
-            self.name = series.name
-            self.active = series.active
+            if let series = &AllDay.seriesByID[id] as &AllDay.Series? {
+                self.id = series.id
+                self.name = series.name
+                self.active = series.active
+            } else {
+                panic("series does not exist")
+            }
         }
     }
 
@@ -229,10 +232,13 @@ pub contract AllDay: NonFungibleToken {
         // initializer
         //
         init (id: UInt64) {
-            let set = (&AllDay.setByID[id] as &AllDay.Set?)!
+            if let set = &AllDay.setByID[id] as &AllDay.Set? {
             self.id = id
             self.name = set.name
             self.setPlaysInEditions = set.setPlaysInEditions
+            } else {
+               panic("set does not exist")
+            }
         }
     }
 
@@ -312,10 +318,13 @@ pub contract AllDay: NonFungibleToken {
         // initializer
         //
         init (id: UInt64) {
-            let play = (&AllDay.playByID[id] as &AllDay.Play?)!
+            if let play = &AllDay.playByID[id] as &AllDay.Play? {
             self.id = id
             self.classification = play.classification
             self.metadata = play.metadata
+            } else {
+                panic("play does not exist")
+            }
         }
     }
 
@@ -374,14 +383,17 @@ pub contract AllDay: NonFungibleToken {
         // initializer
         //
         init (id: UInt64) {
-            let edition = (&AllDay.editionByID[id] as &AllDay.Edition?)!
+           if let edition = &AllDay.editionByID[id] as &AllDay.Edition? {
             self.id = id
             self.seriesID = edition.seriesID
             self.playID = edition.playID
             self.setID = edition.setID
             self.maxMintSize = edition.maxMintSize
             self.tier = edition.tier
             self.numMinted = edition.numMinted
+           } else {
+               panic("edition does not exist")
+           }
         }
     }
 
@@ -611,15 +623,21 @@ pub contract AllDay: NonFungibleToken {
         // borrowNFT gets a reference to an NFT in the collection
         //
         pub fun borrowNFT(id: UInt64): &NonFungibleToken.NFT {
+            pre {
+                self.ownedNFTs[id] != nil: "Cannot borrow NFT, no such id"
+            }
+
             return (&self.ownedNFTs[id] as &NonFungibleToken.NFT?)!
         }
 
         // borrowMomentNFT gets a reference to an NFT in the collection
         //
         pub fun borrowMomentNFT(id: UInt64): &AllDay.NFT? {
             if self.ownedNFTs[id] != nil {
-                let ref = (&self.ownedNFTs[id] as auth &NonFungibleToken.NFT?)!
-                return ref as! &AllDay.NFT
+                if let ref = &self.ownedNFTs[id] as auth &NonFungibleToken.NFT? {
+                    return ref! as! &AllDay.NFT
+                }
+                return nil
             } else {
                 return nil
             }
@@ -717,9 +735,11 @@ pub contract AllDay: NonFungibleToken {
         // Close a Series
         //
         pub fun closeSeries(id: UInt64): UInt64 {
-            let series = (&AllDay.seriesByID[id] as &AllDay.Series?)!
-            series.close()
-            return series.id
+            if let series = &AllDay.seriesByID[id] as &AllDay.Series? {
+                series.close()
+                return series.id
+            }
+            panic("series does not exist")
         }
 
         // Create a Set
@@ -775,9 +795,11 @@ pub contract AllDay: NonFungibleToken {
         // Close an Edition
         //
         pub fun closeEdition(id: UInt64): UInt64 {
-            let edition = (&AllDay.editionByID[id] as &AllDay.Edition?)!
-            edition.close()
-            return edition.id
+            if let edition = &AllDay.editionByID[id] as &AllDay.Edition? {
+                edition.close()
+                return edition.id
+            }
+            panic("edition does not exist")
         }
 
         // Mint a single NFT
@@ -788,7 +810,6 @@ pub contract AllDay: NonFungibleToken {
                 // Make sure the edition we are creating this NFT in exists
                 AllDay.editionByID.containsKey(editionID): "No such EditionID"
             }
-
             return <- self.borrowEdition(id: editionID).mint()
         }
     }