how to create a Form from an object of case class - scala

I am using fold method of form as follows
def regSubmit = Action { implicit request =>
userForm.bindFromRequest.fold({
formWithErrors=>BadRequest(views.html.Error("Registration failed")( formWithErrors.errors))
},
{
userData=>Ok(views.html.regconf("Registration Successful")(**//here I want to send a Form, not data from the form**))
})
How can I create Form from a tuple or single variable, a class or a case class?

userForm will (usually?) be defined as a val, so immutable. It holds the mapping (this field name into a variable in this position of this type, ...) When you use bindFromRequest.fold you are not changing userForm, you are using the mapping information in userForm to generate a new instance of your case class, say userData (or a version of the form with errors in it). Each time you execute that method, you will get a new instance of userData.
userForm.fill(userData) returns a new form instance, a populated instance of the form, so also does not change userForm itself.

Related

how to make mapping function work if the incoming request has less fields than expected

I am experimenting with play/scala. I have following two case classes and I want to map data from form into this model
case class User (
name:String,
age:Int,
female:Boolean,
address:Address
)
case class Address (
fullStreet:String,
county:String,
country:String
)
In controller class, I have following mapping function and action defined
val userForm = Form((mapping("name"->text,
"age"->number,
"female"->boolean,
"address"->mapping("fullStreet"->text,
"county"->text,
"country"->text)(Address.apply)(Address.unapply)
)(User.apply)(User.unapply)))
def post = Action { implicit request =>
val u:Form[User] = userForm.bindFromRequest
Ok(views.html.dataIndex(u))
}
I am facing the following issue: To make the complete code work, I have to create a form which contains all the fields required in mapping as follows:
<h1>Feed User Data</h1>
#helper.form(action=routes.Data.post){
#helper.inputText(userForm("name"))
#helper.inputText(userForm("age"))
#helper.checkbox(userForm("female"))
<fieldset>
#helper.inputText(userForm("address.fullStreet"),'_label -> "Full Street")
#helper.inputText(userForm("address.county"),'_label -> "County")
#helper.select(userForm("address.country"),Seq(""->"---",
"United Kingdom"->"UK",
"France"->"FR") )
</fieldset>
<input type="submit" name="send" value="submit"/>
}
If I create a form with say only input field for name, then bindFromRequest returns None instead of mapping only name field. Is there a way in which the form can contain less fields than required in mapping. I am not talking about fields in form with empty/optional values. I do not want to put the fields in the form at all.
I usually create a case class that represents the form data (probably not all the info from the domain class), and in the controller/service I create the domain entity using my own rules (for instance, a default value for a field not represented on the form)

ScalaFX How do I create a method to react to changes in a var (ObjectProperty)?

I am making a multiplayer game client with ScalaFX GUI and Akka remoting for networking. When my client receives game data it stores it inside Model.gameData. I need my GUI to respond to this variable change.
I used gameData to create data:ObjectProperty in my Model object:
object Model {
var gameData:Option[GameData] = None
val data = new ObjectProperty(this,"data",Model.gameData)
...
}
drawGrid and drawPlayer are methods I use to update the GUI, located in CleintGUI object. I tired using addListener and onChange, they compile but the methods I placed inside of them are never invoked.
object ClientGUI extends JFXApp{
...
Model.data.addListener{ (o: javafx.beans.value.ObservableValue[_ <:Option[GameData]], oldVal: Option[GameData], newVal: Option[GameData]) =>
drawGrid
drawPlayer
}
Model.data onChange {
drawGrid
drawPlayer
}
}
What am I missing? Am I declaring data:ObectProperty or methods inside my ClientGUI incorrectly?
drawGrid and drawPlayer both work when I call them manually by creating an event through submitting a string in a TextField. When I receive GameData I also tried to directly call drawGrid and drawPlayer form inside of my actor class, but I got an error "Not an FX thread".
Edit: I got the GUI to update by mutating control attributes. However, ideally I would want to define the control attributes by using conditional expressions:
val data = new BooleanProperty(this,"data",Model.gameData.isDefined)
val msgLabel = new Label{
text <== when(data) choose " " otherwise "No GameData"
}
But this doesn't work as I can't figure out a way to define BooleanProperty such that when(data) changes value depending on boolean Model.gameData.isDefined
I was adding new elements to the GUI when I received gameData, by using GridPane.add method.
Instead of doing that I added all the controls(gui nodes/elements) during object creation and then changed their relevant attributes when I receive gameData.
e.g. I set Label.text from "No Game Data" to an empty string when I receive gameData:
def update {
ClientGUI.msgLabel = " "
}
I don't think this is the best approach as now I have publicly available vars in a multi threaded application, but since I only change them from one place when I receive new data it should be fine.
Ideally I would want to define the control attributes by using conditional expressions:
val data = new BooleanProperty(this,"data",Model.gameData.isDefined)
val msgLabel = new Label{
text <== when(data) choose " " otherwise "No GameData"
}
But this doesn't work as I can't figure out a way to define BooleanProperty such that when(data) changes value depending on boolean Model.gameData.isDefined

Creating custom DOM events with scalajs

I can't find a way to create custom events with scala-js. For instance, with js you can create a custom event like the following (taken from here):
var event = new CustomEvent('build', { 'detail': elem.dataset.time });
However, there is no constructor for CustomerEvent or Event in scala-js that accept arguments. Also, subclassing either such as:
class DrawEvent extends Event {
override def `type` = "draw"
}
leads to
Uncaught TypeError: undefined is not a function
when trying to construct via new DrawEvent()
Any ideas?
To instantiate javascript classes in ScalaJs you have to use js.Dynamic.newInstance:
This should work for your use case:
val event = js.Dynamic.newInstance(js.Dynamic.global.CustomEvent)("build", js.Dynamic.literal(detail = elem.dataset.time)).asInstanceOf[js.dom.CustomEvent]
There is more info available at the remarks portion (all the way at the bottom) of:
http://www.scala-js.org/doc/calling-javascript.html
Here is the same solution using some imports to make it shorter
import js.Dynamic.{ global => g, newInstance => jsnew, literal => lit }
val event = jsnew(g.CustomEvent)("build", lit(detail = elem.dataset.time)).asInstanceOf[js.dom.CustomEvent]
If you want to stay in the typed DOM (assuming you are talking about the scala-js-dom library), you can do:
new CustomEvent().initCustomEvent('build', false, false, elem.dataset.time)
The constructor you are using is actually only specified in DOM 4 (see MDN).

Setting the property of an object using a variable value in scala

I'm trying to create a restful method to update data in the database, I'm using Scala on Play! framework. I have a model called Application, and I want to be able to update an application in the database. So the put request only requires the id of the application you want to update, then the optional properties you want to update.
So in my routes I have this:
PUT /v1/auth/application controllers.Auth.update_application(id: Long)
The method I currently have is this:
def update_application(id: Long) = Action { implicit request =>
var app = Application.find(id)
for((key, value) <- request.queryString) {
app."$key" = value(0)
//app.name = value(0)
}
val update = Application.update(id, app)
Ok(generate(
Map(
"status" -> "success",
"data" -> update
)
)).as("application/json")
}
In the method above I am looping through the request and the app object as a map instance, then updating the app model to be updated using the model. I know there is an easier way is to create the request string as map and just iterate through the object, but I am doing it this way for learning purposes. I'm new to Play! and Scala, barely a week new.
Is there a way to set a property using a variable dynamically that way? In the above method at the end of the loop that is how I would update a object's property in Groovy. So I'm looking for the equivalent in Scala. If Scala can't do this, what is the best way about going about accomplishing this task? Reflection? I don't want to over-complicate things
Play! provides play.api.data.Forms which allows creating a Form that uses the apply() and unapply() methods of a case class. Then you can call form.fill(app) to create a form with the initial state, bindFromRequest(request) to update the form with the request parameters, and get() to obtain a new instance with updated fields.
Define the form only once:
val appForm = Form(
mapping(
"field1" -> text,
"field2" -> number
)(Application.apply)(Application.unapply)
)
Then in your controller:
val app = appForm.fill(Application.find(id)).bindFromRequest(request).get
val update = Application.update(id, app)
Check out Constructing complex objects from the documentation.

Cannot access the parameter of a Menu.param from a Lift Snippet

I'm trying to extract the parameter from a Lift Menu.param within a snippet so that I can use it to create a named Comet. However, I get a NullPointerException when I try to pass the parameter to the snippet using SnippetDisptach in my Boot.scala, as suggested here:
http://comments.gmane.org/gmane.comp.web.lift/44299
I've created the Menu item as follows:
object AnItemPage {
// create a parameterized page
def menu = Menu.param[Item]("Item", "Item",
s => fetchItem(s), item => item._id.toString) / "item"
private def fetchItem(s:String) : Box[Item] = synchronized {
ItemDAO.findById(ObjectId.massageToObjectId(s))
}
}
I've added the menu to SiteMap. I've also created a Snippet which I would like to pick up the Item parameter. (I'm using fmpwizard's InsertNamedComet library here):
class AddCometItemPage(boxedItem: Box[Item]) extends InsertNamedComet with DispatchSnippet{
val item : Item = boxedItem.openOr(null)
override lazy val name= "comet_item_" + item._id.toString
override lazy val cometClass= "UserItemCometActor"
def dispatch = null
}
My next step is to crate an instance of this class as demonstrated by David Pollak here:
http://comments.gmane.org/gmane.comp.web.lift/44299
This is what I have added to my Boot.scala:
LiftRules.snippetDispatch.append {
case "item_page" => new AddCometItemPage(AnItemPage.menu.currentValue)
}
My item.html references this snippet:
<div class="lift:item_page">
I get the following null pointer exception when I compile and run this:
Exception occurred while processing /item/5114eb4044ae953cf863b786
Message: java.lang.NullPointerException
net.liftweb.sitemap.Loc$class.siteMap(Loc.scala:147)
net.liftweb.sitemap.Menu$ParamMenuable$$anon$9.siteMap(Menu.scala:170)
net.liftweb.sitemap.Loc$class.allParams(Loc.scala:123)
net.liftweb.sitemap.Menu$ParamMenuable$$anon$9.allParams(Menu.scala:170)
net.liftweb.sitemap.Loc$class.net$liftweb$sitemap$Loc$$staticValue(Loc.scala:87)
net.liftweb.sitemap.Menu$ParamMenuable$$anon$9.net$liftweb$sitemap$Loc$$staticValue(Menu.scala:170)
net.liftweb.sitemap.Loc$$anonfun$paramValue$2.apply(Loc.scala:85)
net.liftweb.sitemap.Loc$$anonfun$paramValue$2.apply(Loc.scala:85)
net.liftweb.common.EmptyBox.or(Box.scala:646)
net.liftweb.sitemap.Loc$class.paramValue(Loc.scala:85)
net.liftweb.sitemap.Menu$ParamMenuable$$anon$9.paramValue(Menu.scala:170)
net.liftweb.sitemap.Loc$$anonfun$currentValue$3.apply(Loc.scala:114)
net.liftweb.sitemap.Loc$$anonfun$currentValue$3.apply(Loc.scala:114)
net.liftweb.common.EmptyBox.or(Box.scala:646)
net.liftweb.sitemap.Loc$class.currentValue(Loc.scala:114)
net.liftweb.sitemap.Menu$ParamMenuable$$anon$9.currentValue(Menu.scala:170)
bootstrap.liftweb.Boot$$anonfun$lift$8.apply(Boot.scala:107)
bootstrap.liftweb.Boot$$anonfun$lift$8.apply(Boot.scala:106)
net.liftweb.util.NamedPF$$anonfun$applyBox$1.apply(NamedPartialFunction.scala:97)
net.liftweb.util.NamedPF$$anonfun$applyBox$1.apply(NamedPartialFunction.scala:97)
net.liftweb.common.Full.map(Box.scala:553)
net.liftweb.util.NamedPF$.applyBox(NamedPartialFunction.scala:97)
net.liftweb.http.LiftRules.snippet(LiftRules.scala:711)
net.liftweb.http.LiftSession$$anonfun$net$liftweb$http$LiftSession$$findSnippetInstance$1.apply(LiftSession.scala:1506)
net.liftweb.http.LiftSession$$anonfun$net$liftweb$http$LiftSession$$findSnippetInstance$1.apply(LiftSession.scala:1506)
net.liftweb.common.EmptyBox.or(Box.scala:646)
net.liftweb.http.LiftSession.net$liftweb$http$LiftSession$$findSnippetInstance(LiftSession.scala:1505)
net.liftweb.http.LiftSession$$anonfun$locateAndCacheSnippet$1$1$$anonfun$apply$88.apply(LiftSession.scala:1670)
net.liftweb.http.LiftSession$$anonfun$locateAndCacheSnippet$1$1$$anonfun$apply$88.apply(LiftSession.scala:1669)
Has anybody any idea where I'm going wrong? I've not been able to find a lot of information on Menu.param.
Thank you very much for your help.
f
I have never tried what you are doing, so I am not sure the best way to accomplish it. The way you are using the Loc Param, you are extracting a variable from a URL pattern. In your case, http://server/item/ITEMID where ITEMID is the string representation of an Item, and which is the value that gets passed to the fetchItem function. The function call will not have a value if you just arbitrarily call it, and from what I can see you are requesting a value that is not initialized.
I would think there are two possible solutions. The first would be to use S.location instead of AnItemPage.menu.currentValue. It will return a Box[Loc[Any]] representing the Loc that is currently being accessed (with the parameters set). You can use that Loc to retrive currentValue and set your parameter.
The other option would be to instantiate the actor in your snippet. Something like this:
item.html
<div data-lift="AnItemPage">
<div id="mycomet"></div>
</div>
And then in your AnItemPage snippet, something like this:
class AnItemPage(item: Item) {
def render = "#mycomet" #> new AddCometItemPage(item).render
}
I haven't tested either of those, so they'll probably need some tweaking. Hopefully it will give you a general idea.