I am trying to iterate in a playframework view, but without success for now. I have the following structure:
#if(list != null) {
for(a <- 0 to list.size()/5)
{
// some html, where I want to get the value of a
for(b <- a*5 to a*5+5) // here I want to use the a value again
{
some html
}
}
So my question is how to get the current index of the loop so that I will be able to use it.
You should combine it in one for loop:
#if(list != null) {
#for{a <- 0 to list.size()/5
b <- a*5 to a*5+5}
yield html
}
}
And use option instead of null checking.
Also you can use map function to transform your list. See details in Play documentation - http://www.playframework.com/documentation/2.0/ScalaTemplates
Related
I have the following Scala snippet from my code. I am not able to convert it into functional style. I could do it at other places in my code but not able to change the below one to functional. Issue is once the code exhausts all pattern matching options, then only it should send back "NA". Following code is doing that, but it's not in functional style (for-yield)
var matches = new ListBuffer[List[String]]()
for (line <- caselist){
var count = 0
for (pat <- pattern if (!pat.findAllIn(line).isEmpty)){
count += 1
matches += pat.findAllIn(line).toList
}
if (count == 0){
matches += List("NA")
}
}
return matches.toList
}
Your question is not entirely complete, so I can't be sure, but I believe the following will do the job:
for {
line <- caselist
matches = pattern.map(_.findAllIn(line).toList)
} yield matches.flatten match {
case Nil => List("NA")
case ms => ms
}
This should do the job. Using foreach and filter to generate the matches and checking to make sure there is a match for each line will work.
caseList.foreach{ line =>
val results = pattern.foreach ( pat => pat.findAllIn(line).toList )
val filteredResults = results.filter( ! _.isEmpty )
if ( filteredResults.isEmpty ) List("NA")
else filteredResults
}
Functional doesn't mean you can't have intermediate named values.
Given a Future[Seq[Widget]], where Widget contains a amount : Int property, I'd like to return a Seq[Widget] but for only those Widgets whose amount value is greater than 100. I believe the for { if … } yield { } construct will give me what I want but am unsure how to filter through the Sequence. I have:
val myWidgetFuture : Future[Seq[Widget]] = ...
for {
widgetSeq <- myWidgetFuture
if (??? amount > 100) <— what to put here?
} yield {
widgetSeq
}
If there's a clean non-yield way of doing this that will also work for me.
You don't even need yield. Use map.
val myWidgetFuture: Future[Seq[Widget]] = ???
myWidgetFuture map { ws => ws filter (_.amount > 100) }
If you want to use for … yield with an if filter, you'll need to use two fors:
for {
widgetSeq <- myWidgetFuture
} yield for {
widget <- widgetSeq
if widget.amount > 100
} yield widget
Using a for loop, how can I iterate through a list, with the ability to not iterate over the very last element in the list.
In my case, I would like to not iterate over the first element, and need to iterate through backwards, here is what I have:
for( thing <- things.reverse) {
//do some computation iterating over every element;
//break out of loop when first element is reached
}
You can drop the first item before you reverse it:
for(thing <- things.drop(1).reverse) {
}
For lists, drop(1) is the same as tail if the list is non-empty:
for(thing <- things.tail.reverse) {
}
or you could do the reverse first and use dropRight:
for(thing <- things.reverse.dropRight(1)) {
}
You can also use init if the list is non-empty:
for(thing <- things.reverse.init) {
}
As mentioned by Régis, for(thing <- things.tail.reverse) {}
I'm using getElementsByTagName to return all the select lists on a page - is it possible to then filter these based upon an option value, ie of the first or second item in the list?
The reason is that for reasons I won't go into here there are a block of select lists with number values (1,2,3,4,5 etc) and others which have text values (Blue and Black, Red and Black etc) and I only want the scripting I have to run on the ones with numerical values. I can't add a class to them which would more easily let me do this however I can be certain that the first option value in the list will be "1".
Therefore is there a way to filter the returned list of selects on the page by only those whose first option value is "1"?
I am pretty sure that there is a better solution, but for the moment you can try something like:
var allSelect = document.getElementsByTagName("select");
var result = filterBy(allSelect, 0/*0 == The first option*/, "1"/* 1 == the value of the first option*/);
function filterBy(allSelect, index, theValue) {
var result = [];
for (var i = 0; i < allSelect.length; i++) {
if(allSelect[i].options[index].value == theValue ) {
result.push(allSelect[i]);
}
}
return result;
}
I managed to get this working by wrapping a simple IF statement around the action to be performed (in this case, disabling options) as follows:
inputs = document.getElementsByTagName('select');
for (i = 0; i < inputs.length; i++) {
if (inputs[i].options[1].text == 1) {
// perform action required
}
}
No doubt there is a slicker or more economic way to do this but the main thing is it works for me.
I am trying to find a string in a javascript array in the transformer of a mirth channel. Mirth throws an error when I try to use indexOf function. My understanding is that indexOf is something that browsers add in, rather than a native part of the javascript language itself. ( How do I check if an array includes an object in JavaScript? )
So is array.indexOf just not supported in Mirth? Is there any way to use .indexOf in Mirth? Maybe an alternate syntax? Or do I need to just loop thru the array to search?
This is how I search arrays in a Mirth js transformer:
var Yak = [];
Yak.push('test');
if(Yak.indexOf('test') != -1)
{
// do something
}
Does this give you error?
Mirth uses the Rhino engine for Javascript, and on some earlier versions of the JVM, indexOf appeared to not be supported on arrays. Since upgrading our JVM to 1.6.23 (or higher), indexOf has started working. However, we still have legacy code that, when searching arrays of strings, I just use a loop each time:
var compareString = "blah";
var index = -1;
for (var i = 0; i < myArray.length; ++i)
{
if (myArray[i] == compareString)
{
index = i;
break;
}
}
If you need to do this frequently, you should be able to use a code template to manually add the indexOf function to Array.
Set the code template to global access, and try out something like this (untested code):
Array.prototype.indexOf = function(var compareObject)
{
for (var i = 0; i < myArray.length; ++i)
{
// I don't think this is actually the right way to compare
if (myArray[i] == compareObject)
{
return i;
}
}
return -1;
}
var arr = ['john',1,'Peter'];
if(arr.indexOf('john') > -1)
{
//match. what to do?
console.log("found");
}
else
{
console.log("not found");//not found .. do something
}
var i = ['a', 'b', 'c']
if(i.indexOf('a') > -1)
{
///do this, if it finds something in the array that matches what inside the indexOf()
}
else
{
//do something else if it theres no match in array
}