Map<Integer, Map<String, String>> Actions = new HashMap<Integer, Map<String, String>>();
Map<Integer, List<ActionName>> actionList = Service.getAvailableActionsById(order.id, user.id)
for(Map.Entry<Integer, List<ActionName>> entry : actionList)
{
Map<String, String> actionMap = new HashMap<String, String>();
for(ActionName actionName: entry.getValue()){
actionMap.put(actionName.name(), actionName.name());
}
Actions.put(entry.getKey(), actionMap);
}
--==// For the same functionality above I want to use map inject, while doing as below it unable to inject all the list values to map
Map<Integer, List<ActionName>> actionList = [:]
if ( order.id) actionList = Service.getAvailableActionsById(order.id, session.user.id)
Map Actions = actionList.inject( [:] ) { map, id, values -> map.put( id, values ); return map; }
--=====
Map availableActions = actionList.inject( [:] ) { map, key, listValue ->
map << [ (key) : listValue.collectEntries { [ it.name(), it.name() ] } ]
}
This should give what you are looking for, but I do not get the rationale behind doing this.
inject's closure takes to arguments: result and current element. If you want to call inject() on a map you should treat each element as a Map.Entry:
actionList.inject( [:] ) { map, elem ->
map[ elem.key ] = elem.value // key -> id, value -> values
map
}
Related
I get an object via some 3rd party api. I use a wrapper function to get it and then return a map from its properties:
wrapperFunc() {
def myObj = someapi.getblah().getSomeObect()
return [
aaa: myObj.aaa,
bbb: myObj.bbb,
ccc: myObj.ccc
]
}
Now I could manually go through EVERY property in the object like this, but is there an elegant groovy feature to dynamically build a map from the object's properties?
You could do something like this:
class Widget {
int width
int height
static void main(args) {
def obj = new Widget(width: 7, height: 9)
List<MetaProperty> metaProperties = obj.metaClass.properties
def props = [:]
for(MetaProperty mp : metaProperties) {
props[mp.name] = mp.getProperty(obj)
}
// props will look like [width:7, class:class demo.Widget, height:9]
}
}
This is basically a variant of #jeff-scott-brown's answer.
First, create a class that contains the Object-to-Map logic that uses the Groovy MetaClass to access a type's properties. findAll filters out the "class" property, which I assume you don't care about. The collectEntries line transforms each MetaProperty object into a Map entry.
class ElegantGroovyFeature {
static Map asType(Object o, Class m) {
if (m == Map) {
o.metaClass.properties
.findAll { it.getSetter() != null }
.collectEntries { prop -> [prop.name, prop.getProperty(o)] }
} else {
o.asType(m)
}
}
}
The extension class overrides the asType method, which corresponds to the as operator, enabling you to convert arbitrary objects to Maps using obj as Map expressions:
def obj = someapi.getBlah().getSomeObject()
use (ElegantGroovyFeature) {
def mapOfProperties = obj as Map
}
const obj = { foo: 'bar', baz: 42 };
const map = new Map(Object.entries(obj));
console.log(map); // Map { foo: "bar", baenter code herez: 42 }
Lets say I have a map Map<String, List<Integer>>.
I want to transform this map into Map<String, Map<Integer, Object>> by applying convert() method for each pair of key and element of nested list.
Object convert(String key, Integer value)
How can I achieve that?
I tried something like this:
map.collect { key, list ->
key: list.collectEntries {
[(element): convert(key, element)]
}
}
but I'm getting ClassCastException: ArrayList cannot be cast to Map.
Not at a computer, but try
map.collectEntries { key, list ->
[key, list.collectEntries { element ->
[element, convert(key, element)]
}]
}
You can simplify it a little:
def convert = { it -> it + 1 };
Map<String, List<Integer>> map = [foo: [1, 2, 3], bar: [4, 5, 6]];
map.collectEntries { k, v -> [(k): v.collect { convert(it) }] }
In groovy the original value get overwritten when I change values in a clone list. Does anyone know if I am doing it wrong or it is a bug older groovy?
I am doing something like this:
List<Foo> myFooList = fooList.newFoos.findAll { it.type == "Types}
List<Foo> newFoo = fooList.oldFoos.findAll { it.type == "Types}.clone()
newFoo.each {
it.value = "neeeew value"
}
Foo fooOne = newFoo.each { foooo ->
fooTwo = fooList.oldFoos.find { it.id == foooo.id}
if(fooTwo.value != foooo.value) {
//Here it should go... but it turns out that fooTwo.value == foooo.value
}
}
the clone method called on list produces a new list but with the same objects in it.
you want to build new list with new objects. here is an example:
#groovy.transform.ToString
class Foo{
String type
String value
}
def fooList = [
new Foo(type:"Types", value:'old value1'),
new Foo(type:"Not", value:'old value2'),
new Foo(type:"Types", value:'old value3'),
new Foo(type:"Not", value:'old value4'),
]
def newFooList = fooList.
findAll{it.type=='Types'}.
collect{ new Foo(type:it.type, value:"new value") } //build new array with transformed elements
//check the original list
fooList.each{assert it.value!='new value'}
//check new list
newFooList.each{assert it.value=='new value'}
assert newFooList.size()==2
println fooList
println newFooList
I solved the issue by adding clone of the element as well, any way it became to much of cowboy fix:
List<Foo> myFooList = fooList.newFoos.findAll { it.type == "Types}
List<Foo> newFoo = fooList.oldFoos.findAll { it.type == "Types}.collect {it.clone()}
newFoo.each {
it.value = "neeeew value"
}
Foo fooOne = newFoo.each { foooo ->
fooTwo = fooList.oldFoos.find { it.id == foooo.id}
if(fooTwo.value != foooo.value) {
//Here it should go... but it turns out that fooTwo.value == foooo.value
}
}
I have class in groovy
class WhsDBFile {
String name
String path
String svnUrl
String lastRevision
String lastMessage
String lastAuthor
}
and map object
def installFiles = [:]
that filled in loop by
WhsDBFile dbFile = new WhsDBFile()
installFiles[svnDiffStatus.getPath()] = dbFile
now i try to sort this with custom Comparator
Comparator<WhsDBFile> whsDBFileComparator = new Comparator<WhsDBFile>() {
#Override
int compare(WhsDBFile o1, WhsDBFile o2) {
if (FilenameUtils.getBaseName(o1.name) > FilenameUtils.getBaseName(o2.name)) {
return 1
} else if (FilenameUtils.getBaseName(o1.name) > FilenameUtils.getBaseName(o2.name)) {
return -1
}
return 0
}
}
installFiles.sort(whsDBFileComparator);
but get this error java.lang.String cannot be cast to WhsDBFile
Any idea how to fix this? I need to use custom comparator, cause it will be much more complex in the future.
p.s. full source of sample gradle task (description of WhsDBFile class is above):
project.task('sample') << {
def installFiles = [:]
WhsDBFile dbFile = new WhsDBFile()
installFiles['sample_path'] = dbFile
Comparator<WhsDBFile> whsDBFileComparator = new Comparator<WhsDBFile>() {
#Override
int compare(WhsDBFile o1, WhsDBFile o2) {
if (o1.name > o2.name) {
return 1
} else if (o1.name > o2.name) {
return -1
}
return 0
}
}
installFiles.sort(whsDBFileComparator);
}
You can try to sort the entrySet() :
def sortedEntries = installFiles.entrySet().sort { entry1, entry2 ->
entry1.value <=> entry2.value
}
you will have a collection of Map.Entry with this invocation. In order to have a map, you can then collectEntries() the result :
def sortedMap = installFiles.entrySet().sort { entry1, entry2 ->
...
}.collectEntries()
sort can also take a closure as parameter which coerces to a Comparator's compare() method as below. Usage of toUpper() method just mimics the implementation of FilenameUtils.getBaseName().
installFiles.sort { a, b ->
toUpper(a.value.name) <=> toUpper(b.value.name)
}
// Replicating implementation of FilenameUtils.getBaseName()
// This can be customized according to requirement
String toUpper(String a) {
a.toUpperCase()
}
I would like to create a method that orders an IEnumerable List by a given property where the property is passed into the method by a string i.e. (Mind you the first code example does not work, but the second does and is what I am trying to emulate dynamically).
string sortName = "SerialNumber";
IEnumerable<PartSummary> partList = FunctionToCreateList();
partOrderedList = partList.OrderBy(what do I stick in here);
that would be equivalent to
IEnumerable<PartSummary> partList = FunctionToCreateList();
partOrderedList = partList.OrderBy(p => p.SerialNumber);
How can I accomplish this?
Are you saying you want to pass the order by in to your method? If so, you can use this:
Expression<Func<PartSummary, bool>> orderByClause
Then you can do this:
partOrderedList = partList.OrderBy(orderByClause);
Then you can handle your order by in your business layer or wherever you wish.
Okay, update: If you want to pass in the column name as a string you can do something like as follows:
Create a static class for an extension method (reference: http://social.msdn.microsoft.com/Forums/en-US/linqprojectgeneral/thread/39028ad2-452e-409f-bc9e-d1b263e921f6/):
static class LinqExtensions
{
public static IQueryable<T> OrderBy<T>(this IQueryable<T> source, string sortingColumn, bool isAscending)
{
if (String.IsNullOrEmpty(sortingColumn))
{
return source;
}
ParameterExpression parameter = Expression.Parameter(source.ElementType, String.Empty);
MemberExpression property = Expression.Property(parameter, sortingColumn);
LambdaExpression lambda = Expression.Lambda(property, parameter);
string methodName = isAscending ? "OrderBy" : "OrderByDescending";
Expression methodCallExpression = Expression.Call(typeof(Queryable), methodName,
new Type[] { source.ElementType, property.Type },
source.Expression, Expression.Quote(lambda));
return source.Provider.CreateQuery<T>(methodCallExpression);
}
}
Then you can create your method:
static IQueryable<PartSummary> FunctionToCreateList()
{
IList<PartSummary> list = new List<PartSummary>();
list.Add(new PartSummary
{
Id = 1,
SerialNumber = "A",
});
list.Add(new PartSummary
{
Id = 2,
SerialNumber = "B",
});
return list.AsQueryable();
}
And then call your method:
static void Main(string[] args)
{
IQueryable<PartSummary> partOrderedList = FunctionToCreateList();
PartSummary partSummary = new PartSummary();
string sortBy = "Id";
partOrderedList = partOrderedList.OrderBy(sortBy, false);
foreach (PartSummary summary in partOrderedList)
{
Console.WriteLine(summary.Id + ", " + summary.SerialNumber);
}
Console.ReadLine();
}
Now you can pass in the column name as a string and sort.
Hope this helps!
You can also avoid extending and just use a compiled expression tree to accomplish this:
public Func<T, object> ResolveToProperty<T>(String propertyName)
{
Type t = typeof(T);
var paramExpression = Expression.Parameter(t, "element");
var propertyExpression = Expression.Property(paramExpression, propertyName);
return Expression.Lambda<Func<T, object>>(propertyExpression, paramExpression).Compile();
}
string sortName = "SerialNumber";
IEnumerable<PartSummary> partList = FunctionToCreateList();
var partOrderedList = partList.OrderBy(ResolveToProperty<PartSummary>(sortName));