I'm using scala-arm library to automatically release/close resources (for example InputStream).
But the problem is that code below returns ExtractableManagedResource[Int], not just Int as I want.
val result = for(responseStream <- managed(response.getResponseBodyAsStream)) yield {
val localResult: Int = 1
localResult
}
// result is of type ExtractableManagedResource[Int]
Is there any option to return Int and overcome wrapping result to ExtractableManagedResource?
EDIT: I know that I can just declre result variable as var and assign to it from inside the for-comprehension, but I want more scala-idiomatic way, i.e. without using var
this is easier to implement with the monadic approach by using the aquireAndGet feature
managed(response.getResponseBodyAsStream) acquireAndGet {
responseStream =>
val localResult: Int = 1
localResult
}
From the documentation:
result.opt.get
Refer to your own link, under the title "Monadic style", for further details.
Related
So the context is that I require to update a value in a single document, I have a Mono, the parameter Object contains values such as username (to find the correct user by unique username) and an amount value.
The problem is that this value (due to other components of my application) is the value by which I need to increase/decrease the users balance, as opposed to passing a new balance. I intend to do this using two Monos where one finds the user, then this is combined to the other Mono with the inbound request, where I can then perform a simple sum (i.e balance + changeRequest.amount) then return this to the document database.
override fun increaseBalance(changeRequest: Mono<ChangeBalanceRequestResource>): Mono<ChangeBalanceResponse> {
val changeAmount: Mono<Decimal128> = changeRequest.map { it.transactionAmount }
val user: Mono<User> = changeRequest.flatMap { rxUserRepository.findByUsername(it.username)
val newBalace = user.map {
val r = changeAmount.block()
it.balance = sumBalance(it.balance!!, r!!)
rxUserRepository.save(it)
}
.flatMap { it }
.map { it.balance!! }
return Mono.just(ChangeBalanceResponse("success", newBalace.block()!!))
}
Obviously I'm trying to achieve this in a non-blocking fashion. I'm also open to using only a single Mono if that's possible/optimal. I also appreciate I've truly butchered the example and used .block as a placeholder to illustrate what I'm trying to achieve.
P.S this is my first post, so any tips on how to express my problem clearer would be useful.
Here's how I would do this in Java (Using Double instead of Decimal128):
public Mono<ChangeBalanceResponse> increaseBalance(Mono<ChangeBalanceRequestResource> changeRequest) {
Mono<Double> changeAmount = changeRequest.map(a -> a.transactionAmount());
Mono<User> user = changeRequest.map(a -> a.username()).flatMap(RxUserRepository::findByUsername);
return Mono.zip(changeAmount,user).flatMap(t2 -> {
Double changeAmount = t2.getT1();
User user = t2.getT2();
//assumes User is chained
return rxUserRepository.save(user.balance(sumBalance(changeAmount,user.balance())));
}).map(res -> new ChangeBalanceResponse("success",res.newBalance()))
}
I have a scenario like this.
private val feeder = Array(200, 404).map(e => Map("code" -> e)).random.circular
private val search = scenario("search")
.feed(feeder)
.exec(http("search")
.get("/search/")
.headers(headers)
.check( if "${code}".equals(200) jsonPath("$.body").exists else jsonPath("$.exception").exists )
Is there a way I can achieve this kinda conditional check. As of now, the observed behavior is, "${code}".equals(200) will always return false.
You can access a session inside jsonPath and extract code from it manually
.check(jsonPath(session =>
if (session("code").as[Int].equals(200)) "$.body"
else "$.exception"
).exists)
According to the documentation, there is the following construct to achieve this:
// with a Gatling EL String condition that resolves a Boolean
.checkIf("#{bool}") {
jsonPath("$..foo")
}
// with a function
.checkIf(session => session("key").as[String] == "executeCheck") {
jsonPath("$..foo")
}
My Google-fu is letting me down, so I'm hoping you can help
I'm building some webservices is the play framework using scala and anorm for database access
One of my calls is to update an existing row in a database - i.e run a query like
UPDATE [Clerks]
SET [firstName] = {firstName}
,[lastName] = {lastName}
,[login] = {login}
,[password] = {password}
WHERE [id] = {id}
My method receives a clerk object BUT all the parameters are optional (except the id of course) as they may only wish to update a single column of the row like so
UPDATE [Clerks]
SET [firstName] = {firstName}
WHERE [id] = {id}
So I want the method to check which clerk params are defined and build the 'SET' part of the update statement accordingly
It seems like there should be a better way than to go through each param of the clerk object, check if it is defined and build the query string - but I've been unable to find anything on the topic so far.
Does anyone have any suggestions how this is best handled
As the commenters mentioned it appears to not be possible - you must build the query string yourself.
I found that examples around this lacking and it took more time to resolve this than it should have (I'm new to scala and the play framework, so this has been a common theme)
in the end this is what I implemented:
override def updateClerk(clerk: Clerk) = {
var setString: String = "[modified] = {modified}"
var params: collection.mutable.Seq[NamedParameter] =
collection.mutable.Seq(
NamedParameter("modified", toParameterValue(System.currentTimeMillis / 1000)),
NamedParameter("id", toParameterValue(clerk.id.get)))
if (clerk.firstName.isDefined) {
setString += ", [firstName] = {firstName}"
params = params :+ NamedParameter("firstName", toParameterValue(clerk.firstName.getOrElse("")))
}
if (clerk.lastName.isDefined) {
setString += ", [lastName] = {lastName}"
params = params :+ NamedParameter("lastName", toParameterValue(clerk.lastName.getOrElse("")))
}
if (clerk.login.isDefined) {
setString += ", [login] = {login}"
params = params :+ NamedParameter("login", toParameterValue(clerk.login.getOrElse("")))
}
if (clerk.password.isDefined) {
setString += ", [password] = {password}"
params = params :+ NamedParameter("password", toParameterValue(clerk.password.getOrElse("")))
}
if (clerk.supervisor.isDefined) {
setString += ", [isSupervisor] = {supervisor}"
params = params :+ NamedParameter("supervisor", toParameterValue(clerk.supervisor.getOrElse(false)))
}
val result = DB.withConnection { implicit c =>
SQL("UPDATE [Clerks] SET " + setString + " WHERE [id] = {id}").on(params:_*).executeUpdate()
}
}
it likely isn't the best way to do this, however I found it quite readable and the parameters are properly handled in the prepared statement.
Hopefully this can benefit someone running into a similar issue
If anyone wants to offer up improvements, they'd be gratefully received
Since roughly 2.6.0 this is possible directly with anorm using their macros, http://playframework.github.io/anorm/#generated-parameter-conversions
Here is my example:
case class UpdateLeagueFormInput(transferLimit: Option[Int], transferWildcard: Option[Boolean], transferOpen: Option[Boolean])
val input = UpdateLeagueFormInput(None, None, Some(true))
val toParams: ToParameterList[UpdateLeagueFormInput] = Macro.toParameters[UpdateLeagueFormInput]
val params = toParams(input)
val dynamicUpdates = params.map(p => {
val snakeName = camelToSnake(p.name)
s"$snakeName = CASE WHEN {${p.name}} IS NULL THEN l.$snakeName ELSE {${p.name}} END"
})
val generatedStmt = s"""UPDATE league l set ${dynamicUpdates.mkString(", ")} where league_id = ${league.leagueId}"""
SQL(generatedStmt).on(params: _*).executeUpdate()
producing:
UPDATE league l set transfer_limit = CASE WHEN null IS NULL THEN l.transfer_limit ELSE null END, transfer_wildcard = CASE WHEN null IS NULL THEN l.transfer_wildcard ELSE null END, transfer_open = CASE WHEN true IS NULL THEN l.transfer_open ELSE true END where league_id = 26;
Notes:
The camelToSnake function is just my own (There is an obvious ColumnNaming.SnakeCase available for parser rows, but I couldn't find something similar for parameter parsing)
My example string interpolates {league.leagueId}, when it could treat this as a parameter as well
Would be nice to avoid the redundant sets for null fields, however I don't think it's possible, and in my opinion clean code/messy auto-generated sql > messy code/clean auto-generated sql
I am using Lift web framework.
I am implementing an auto-complete text box. When I enter some value in the box a drop-down list opens. If I select a value from that list, only then I am able to access value of text box. If I write a value by myself then I get an empty value.
My code :
var friend_name=""
"#bdayReminder" #> AutoComplete("",
getAllName _,
value => takeAction(value),
List("minChars" -> "3"))
private def takeAction(str: String) {
friend_name = str
}
Please suggest a solution
Disclaimer: I'm the author of following library.
I think lift-combobox could achieve what you want, since it has a feature that let user created the value on-the fly. It use select2 jQuery plugin, so you will have a nice look and feel for the drop-down menu.
For example if you need to get the user-created value, it will simply as the following, note that we usually using Option[T] to denote that the value may not be presented, for example, the user may not selected any item in drop-menu at all:
var friend_name: Option[String] = None
val friendsMenu = new ComboBox(
default = None,
allowCreate = true
) {
// This is where you build your combox suggestion
override def onSearching(term: String): List[ComboItem] = {
val names = List(
ComboItem("f1", "Brian"), ComboItem("f2", "Alice"),
ComboItem("f3", "Luke"), ComboItem("f4", "Smith"),
ComboItem("f5", "Brandon")
)
names.filter(_.text.contains(term))
}
override def onItemSelected(selected: Option[ComboItem]): JsCmd = {
friend_name = selected
// The returned JsCmd will be executed on client side.
Alert("You selected:" + selected)
}
// What you want to do if user added an item that
// does not exist when allowCreate = true.
override def onItemAdded(text: String): JsCmd = {
friend_name = Some(text)
}
}
"#bdayReminder" #> friendsMenu.combobox
Imagine you have the following TreeMap:
var dates = new TreeMap[Long, Tuple2[Int, Double]]()
I know I can loop through it with:
dates.foreach { case (date, (id, rotation)) =>
...
}
But in my code, this loop takes place within another loop and I would therefore like to advance myself in the dates keys, typically with a currIndex : Int variable that I would increment according to a condition.
I thought one could do something like:
date = dates.keys(currIndex)
but it doesn't look like this is possible... any idea how to do that?
Edit: trying to address your comment:
You can convert the whole keys to an IndexedSeq beforehand:
val keysSeq = dates.keySet.toIndexedSeq
// later, obtain an index
val index: Int = /* ... */
// lookup the key
val (valueInt, valueDouble) = dates(keysSeq(index))
Previous answer
You could try something like this:
dates.iterator.zipWithIndex.foreach {
case ((key, (valueInt, valueDouble)), index) =>
}
Would that work for you? I'm not sure I properly understand your requirement of “increment[ing currIndex] according to a condition”…