server: Simplify the validators

server/app/com/xsn/explorer/services/BalanceService.scala

@@ -9,9 +9,8 @@ import com.xsn.explorer.data.async.BalanceFutureDataHandler
 import com.xsn.explorer.models.WrappedResult
 import com.xsn.explorer.models.persisted.Balance
 import com.xsn.explorer.parsers.BalanceOrderingParser
-import com.xsn.explorer.services.validators.AddressValidator
+import com.xsn.explorer.services.validators._
 import javax.inject.Inject
-import org.scalactic.Good
 
 import scala.concurrent.ExecutionContext
 
@@ -35,11 +34,7 @@ class BalanceService @Inject() (
   def getHighest(limit: Limit, lastSeenAddressString: Option[String]): FutureApplicationResult[WrappedResult[List[Balance]]] = {
     val result = for {
       _ <- paginatedQueryValidator.validate(PaginatedQuery(Offset(0), limit), 100).toFutureOr
-
+      lastSeenAddress <- validate(lastSeenAddressString, addressValidator.validate).toFutureOr
-      lastSeenAddress <- lastSeenAddressString
-          .map { string => addressValidator.validate(string).map(Option.apply) }
-          .getOrElse(Good(None))
-          .toFutureOr
 
       data <- balanceFutureDataHandler.getHighestBalances(limit, lastSeenAddress).toFutureOr
     } yield WrappedResult(data)

server/app/com/xsn/explorer/services/BlockService.scala

@@ -14,7 +14,7 @@ import com.xsn.explorer.models.rpc.{Block, TransactionVIN}
 import com.xsn.explorer.models.values.{Blockhash, Height}
 import com.xsn.explorer.parsers.OrderingConditionParser
 import com.xsn.explorer.services.logic.{BlockLogic, TransactionLogic}
-import com.xsn.explorer.services.validators.BlockhashValidator
+import com.xsn.explorer.services.validators._
 import com.xsn.explorer.util.Extensions.FutureOrExt
 import javax.inject.Inject
 import org.scalactic.{Bad, Good}
@@ -42,11 +42,7 @@ class BlockService @Inject() (
       implicit writes: Writes[BlockHeader]): FutureApplicationResult[JsValue] = {
 
     val result = for {
-      lastSeenHash <- lastSeenHashString
+      lastSeenHash <- validate(lastSeenHashString, blockhashValidator.validate).toFutureOr
-          .map { string => blockhashValidator.validate(string).map(Option.apply) }
-          .getOrElse(Good(None))
-          .toFutureOr
-
       _ <- paginatedQueryValidator.validate(PaginatedQuery(Offset(0), limit), maxHeadersPerQuery).toFutureOr
       orderingCondition <- orderingConditionParser.parseReuslt(orderingConditionString).toFutureOr
 

server/app/com/xsn/explorer/services/TransactionService.scala

@@ -9,9 +9,8 @@ import com.xsn.explorer.data.async.TransactionFutureDataHandler
 import com.xsn.explorer.models._
 import com.xsn.explorer.models.transformers._
 import com.xsn.explorer.parsers.{OrderingConditionParser, TransactionOrderingParser}
-import com.xsn.explorer.services.validators.{AddressValidator, BlockhashValidator, TransactionIdValidator}
+import com.xsn.explorer.services.validators._
 import javax.inject.Inject
-import org.scalactic._
 import org.slf4j.LoggerFactory
 
 import scala.concurrent.ExecutionContext
@@ -57,11 +56,7 @@ class TransactionService @Inject() (
       _ <- paginatedQueryValidator.validate(PaginatedQuery(Offset(0), limit), maxTransactionsPerQuery).toFutureOr
       orderingCondition <- orderingConditionParser.parseReuslt(orderingConditionString).toFutureOr
 
-      lastSeenTxid <- lastSeenTxidString
+      lastSeenTxid <- validate(lastSeenTxidString, transactionIdValidator.validate).toFutureOr
-          .map { string => transactionIdValidator.validate(string).map(Option.apply) }
-          .getOrElse(Good(None))
-          .toFutureOr
-
       transactions <- transactionFutureDataHandler.getBy(address, limit, lastSeenTxid, orderingCondition).toFutureOr
     } yield {
       val lightTxs = transactions.map(toLightWalletTransaction)
@@ -88,11 +83,7 @@ class TransactionService @Inject() (
       blockhash <- blockhashValidator.validate(blockhashString).toFutureOr
       _ <- paginatedQueryValidator.validate(PaginatedQuery(Offset(0), limit), maxTransactionsPerQuery).toFutureOr
 
-      lastSeenTxid <- lastSeenTxidString
+      lastSeenTxid <- validate(lastSeenTxidString, transactionIdValidator.validate).toFutureOr
-          .map { string => transactionIdValidator.validate(string).map(Option.apply) }
-          .getOrElse(Good(None))
-          .toFutureOr
-
       r <- transactionFutureDataHandler.getByBlockhash(blockhash, limit, lastSeenTxid).toFutureOr
     } yield WrappedResult(r)
 
@@ -108,11 +99,7 @@ class TransactionService @Inject() (
       blockhash <- blockhashValidator.validate(blockhashString).toFutureOr
       _ <- paginatedQueryValidator.validate(PaginatedQuery(Offset(0), limit), maxTransactionsPerQuery).toFutureOr
 
-      lastSeenTxid <- lastSeenTxidString
+      lastSeenTxid <- validate(lastSeenTxidString, transactionIdValidator.validate).toFutureOr
-          .map { string => transactionIdValidator.validate(string).map(Option.apply) }
-          .getOrElse(Good(None))
-          .toFutureOr
-
       transactions <- transactionFutureDataHandler.getTransactionsWithIOBy(blockhash, limit, lastSeenTxid).toFutureOr
     } yield {
       val lightTxs = transactions.map(toLightWalletTransaction)

server/app/com/xsn/explorer/services/validators/package.scala

@@ -2,7 +2,7 @@ package com.xsn.explorer.services
 
 import com.alexitc.playsonify.core.ApplicationResult
 import com.alexitc.playsonify.models.ApplicationError
-import org.scalactic.{One, Or}
+import org.scalactic.{Good, One, Or}
 
 package object validators {
 
@@ -10,4 +10,10 @@ package object validators {
     val maybe = builder(string)
     Or.from(maybe, One(error))
   }
+
+  def validate[T](maybe: Option[String], validator: String => ApplicationResult[T]): ApplicationResult[Option[T]] = {
+    maybe
+        .map { string => validator(string).map(Option.apply) }
+        .getOrElse(Good(None))
+  }
 }