Given a String list
val www = List("http://bloomberg.com", "http://marketwatch.com");
I want to dynamically generate
<span id="span1">http://bloomberg.com</span>
<span id="span2">http://marketwatch.com</span>
def genSpan(web: String) = <span id="span1"> + web + </span>;
www.map(genSpan); // How can I pass the loop index?
How can I use the Scala map function to generate the ids (span1, span2), as 1 and 2 are the loop indexes?
Or is the only way is to use for comprehension?
The easiest way is to use zipWithIndex which turns a list into a list of tuples (value,index). In your case,
def genSpan(web: String, id: Int) = {
<span id={ "span%d".format(id) }> { web } </span>
}
www.zipWithIndex.map(x => genSpan(x._1,x._2+1))
Note that the index, x._2, starts from zero but you want to start from one, so I added one in the call to genSpan. Note also that you can set attributes using Scala code by wrapping the Scala code in {}.
Related
I'm trying to compare two lists by using only scala templates from play framework. My goal is to show all items listA in a table and then find out if listA has objects containing the same values as in listB to change the appearence of the duplicated items.
So let's assume a.id has an equivalent b.id, then i want a.id to appear in the list but crossed-out.
Example Input: listA has 5 objects with the attributes name and id. listB has 2 objects with the attributes id and xxx.
Desired Output: I want to display all items from listA (using the first scala #for loop), but if the id already exists in listB, i want the item to be crossed out in my table.
This is what i got so far:
<tbody>
#for(a <- aList){
#for(b <- bList){
<thead>
<tr>
<th>Key</th>
<th>Name</th>
</tr>
</thead>
#if(a.id == b.id){
<tr>
<td><s>#a.id</s></td>
<td><s>#a.name</s></td>
</tr>
} else {
<tr>
<td>#a.id</td>
<td>#a.name</td>
</tr>
}
}
} </tbody>
So far the code works, but now every element from listA appears as many times as the second loop goes through, which absolutely makes sense, but how can i prevent that?
You should probably do this in Scala code, rather than inside the template.
What you want is listA with a Boolean for each element telling you if it's in listB. Here's a simple way to do this:
val listAWithBool = listA.map(a => (a, listB.map(_.id).contains(a.id)))
Then, in your for loop, you can do
#for((a,inB) <- listAWithBool){
#if(inB){
...
} else {
...
}
}
EDIT
Since you're using Play Java, most of what I wrote previously will be hard to put in code, since it's functional programming. A possible solution is to put all that in your template, which allows scala code; just put this at the top of your template (under the list of parameters):
#listAWithBool = #{
listA.map(a => (a, listB.map(_.id).contains(a.id)))
}
Now to explain the weird for((a, inB) <- listAWithBool) syntax: just as for(a <- listA) means "extract all values from my list and do the following with each of them, giving it the name a", this now means "extract all pairs of values from my list and do the following with each of them, giving name a and inB to its two elements.
Remember that we have built listAWithBool to be a list of pairs (as return type of the lambda) of type List[A, Boolean], so the compiler will be able to understand that a is of type A and inB is of type Boolean.
var valueA= document.getElementById(#a.id);
var valueB= document.getElementById(#b.id);
#if(valueA == valueB){
}
Or
You can use
if(valueA.contains(valueB)){
}
I'm trying to create a dynamic list of URLs in Twirl template with Play with no luck. I can't seem to map over a collection to create list of URLs for some reason. This is what I have:
#casesCollection.map(e => {
<td>#e.name</td>
})
The part within the href does not compile. Any ideas how this issue can be solved?
You've not given enough details about the type of casesCollection and the error you're getting.
Here's a simplified example that works:
In the controller:
def index = Action {
val casesCollection = List("A", "B", "C")
Ok(views.html.xxx(casesCollection))
}
The view xxx.scala.html:
#(casesCollection: List[String])
<ul>
#casesCollection.map { e =>
<li>#e</li>
}
</ul>
In my example casesCollection is a simple List of Strings. You may have a list of some sort of objects, but it should be easy to adapt.
I use SetHtml() all the time to swap chunks of HTML as part of the return trip of an ajax call, ie. when my "Edit Item" ajax call returns, I swap the contents of with form elements representing the "Item" to be edited.
Now I'm trying to add a new item to a list (so that "Item 2" appears as the next li under "Item 1"). My html looks like (this is a greatly simplified version) this:
<div data-lift="form.ajax">
<div data-lift="JsCmdTest">
<test:submitbutton></test:submitbutton>
<ul id="targetdiv">
<li>Item 1</li>
</ul>
</div>
</div>
and my Lift code looks like this
class JsCmdTest extends StatefulSnippet
{
def dispatch = { case "render" => render }
def bindStuff(ns: NodeSeq): NodeSeq =
{
bind("test", ns,
"submitbutton" -> SHtml.ajaxButton("Go", ()=> {
val newLi = Jx(<div>Item 2</div>)
(ElemById("targetdiv") ~> JsFunc("appendChild", newLi.toJs)).cmd
})
)
}
def render: (NodeSeq)=>NodeSeq = (ns: NodeSeq) => {
bindStuff(ns)
}
}
When I run this, the ajax call is fired, and the response looks fine, but I get the following error in the browser console:
The server call succeeded, but the returned Javascript contains an error: NotFoundError: Failed to execute 'appendChild' on 'Node': The new child element is null.
WANTED: a way to append replacement HTML to an existing < ul >. I feel like the way I'm going about appending seems way more esoteric than probably needed, but i haven't found any other way to do it.
Thanks in advance!
you're using a very old syntax for binding. If I am not mistaken, a new way for bindings was introduced somewhere in lift-2, and it is the recommended one since somewhere in lift-2.2. (I'll write the syntax below.)
JsFunc is an anonymous function, like def local(a: A): B. You don't need to send anonymous function, you can send the code directly. (See below.)
So, I recommend something like this:
import net.liftweb.http.js.{JsExp, JsCmd, JsCmds}
import net.liftweb.http.js.jquery.JqJE.{JqAppend, JqId}
def render = {
val appendJs: JsExp = JqId("targetdiv") ~> JqAppend(newLi)
"#mySubmitButton" #> SHtml.ajaxButton("Go", () => appendJs.cmd)
}
You'll also have to adapt the HTML a little, like using a normal <button> with id="mySubmitButton".
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.
Another lift beginner question:
I want to render a HTML Definition List in a Lift Snippet like this:
<dl>
<dt>Name</dt>
<dd>Seppl</dd>
<dt>Street</dt>
<dd>abc</dd>
</dl>
The snippet-template looks now like this:
<dl>
<div class="definition">
<dt>Term</dt>
<dd>Description</dd>
</div>
</dl>
The Scala Snippet code:
def render = {
val values=List(("Name", "Seppl"), ("Street", "abc"))
".definition" #> values.map(value =>
("dt" #> value._1) &
("dd" #> value._2))
}
This works, but I want a definition list without div-Tags (I think, this it isn't valid HTML.)
Is this possible with CSS Transformers?
As you don't seem to use CSS I would recommend you to use the following:
Snippet Template code:
<div class="lift:render"/>
Scala Snippet code:
def render = {
val values=List(("Name", "Seppl"), ("Street", "abc"))
values.map(value =>
<dt>{value._1}</dt>
<dd>{value._2}</dd>
)
}
Of course I avoid using CSS selectors so I don't know if it is exactly what you are looking for.
See http://www.assembla.com/spaces/liftweb/wiki/Binding_via_CSS_Selectors
At the end of the page (Iteration) there's an example with unordered list.