List data type

Value range of the List data type

In FirstSpirit, elements of the template development can be grouped in:

• Lists
• Sets
• Maps

FirstSpirit provides the data type List for the editing / processing of values which represent an ordered, indexed set of list elements. This data type enables a grouping of elements. Lists are very flexible and can be extended as required. By specifying an index value, which determines the position within the list, it is possible to define the position in the list in which an element is to be inserted or read out. Unlike the data type Set, elements can occur more than once within a list.

The data type List can also be looked up in the Sun API documentation:

java.util.List

Definition

Lists can also be generated via [ ] (square brackets). The following syntax must be fulfilled:

LIST := '[]' | [ EXPRESSION [',' EXPRESSION ]* ] ']' | '[' EXPRESSION' .. ' EXPRESSION ']'

The following code example generates an empty list and assigns to it the "empty_list" variable:

  $CMS_SET(empty_list, [])$

If a filled list is to be generated, i.e. a list which already contains elements, the elements are simply passed as a comma-separated list within the square brackets. The code example generates a new, filled list "list":

  $CMS_SET(list, [1,2,3])$

Access to elements in the list

Elements in a list are accessed via the list's index.

The index can be defined by a constant value:

list[2] 

or via a variable:

list[i]

analogous to this:

list.get(2)

list.get(i)

Examples:

$CMS_VALUE(list.get(2))$ 

or:

$CMS_SET(i, 2)$
$CMS_VALUE(list, [i])$

Both examples return the third element in the list (Index always begins with 0!).

Analogous to this a new list element can be set via the index in a specific position in the list:

$CMS_SET(list[0], "new")$

With this instruction the "new" string is set in the first position in the list.

All elements of a list can also be set simultaneously. The position then depends on the order of the elements within the $CMS_SET(list, [...])$ instruction.

$CMS_SET(list, ["a","b","c"])$

Sorting the list elements

The sort method can be used to sort lists in ascending order:

$CMS_SET(list, ["C", "E", "B", "D", "A"])$
$CMS_VALUE(list.sort)$

The output is:

[A, B, C, D, E]

The reverse method reverses the order of the list elements:

$CMS_SET(list, ["C", "E", "B", "D", "A"])$
$CMS_VALUE(list.reverse)$

Output:

[A, D, B, E, C]

Both methods are combined to obtain sorting in descending order:

$CMS_SET(list, ["C", "E", "B", "D", "A"])$
$CMS_VALUE(list.sort.reverse)$

Output:

[E, D, C, B, A]

Methods on list objects

The table below lists all methods which can be invoked on objects of data type List .

add(List)

Overview

add(Object)

Overview

add(int, Object)

Overview

addAll(Collection)

Overview

addAll(int, Collection)

Overview

clear

Overview

compareTo(Comparable)

Overview

contains(Object)

Overview

containsAll(Collection)

Overview

copy

Overview

distinct(Lambda)

This method filters a collection and returns only the first occurrence relating to a lambda expression.

It can be used to eliminate or ignore duplicates of a list according to a given condition. For this reason, it can be used for glossaries or summaries, which can then serve linked, for example, as navigational element.

See page Mapping expressions (lambda).

Overview

equals(Object)

Overview

filter(String)

Overview

filter(Lambda)

If lists have several attributes per element (comparable with a dataset with several columns), the elements can be filtered by the individual attributes using the method .filter(Lambda).

See page Mapping expressions (lambda).

Overview

first

Overview

fold(Lambda, Map)

This method folds the collection with the given lambda expression and start value.

See page Mapping expressions (lambda).

Overview

get(Range)

Overview

get(int)

Overview

getClass

The .getClass() (in Bean syntax: .class) method returns the class of the invoking object (cf. java.lang.Class).

Invocation:

$CMS_VALUE(myString.class)$
$CMS_VALUE(myString.getClass())$

Output:

java.lang.String

Overview

hashCode

Overview

indexOf(Object)

Overview

isCase(Object)

Overview

isEmpty

The .isEmpty() (in Bean syntax: .isEmpty) method checks whether an expression or object is empty, e.g. storeElement.isEmpty(). The result of the semantic check depends on the expression or object, e.g. a character string is empty if it does not contain any characters. In the case of objects with complex values or objects, the object decides when it is empty. The data type DomElement for example always contains an empty document, thus it is never null. For this reason, checking an empty DOM editor input component by using the method .isNull()returns the value false, whereas checking the component with .isEmpty() would return the value true.

The method .isEmpty() returns a Boolean value as the check result. true is the check result if the expression or object is empty and false if not.

Overview

isNull

The .isNull() (in Bean syntax: .isNull) method checks whether an expression or object is null , e.g. storeElement.isNull(). In the case of objects with complex values or objects, the object decides when it is null. The data type DomElement for example always contains an empty document, thus it is never null. For this reason, checking an empty DOM editor input component by using the method .isNull() returns the value false, whereas checking the component with .isEmpty() would return the value true.

The method .isNull() returns a Boolean value as the check result. true is the check result if the expression or object is null and false if not.

Overview

iterator

Overview

last

Overview

lastIndexOf(Object)

Overview

length

Overview

listIterator

Overview

listIterator(int)

Overview

map(String)

Overview

map(Lambda)

See page Mapping expressions (lambda).

Overview

max

Overview

max(Comparator)

Overview

max(Lambda)

This method delivers the maximum element concerning to the given comparator.

See page Mapping expressions (lambda).

Overview

min

Overview

min(Comparator)

Overview

min(Lambda)

This method delivers the minimum element concerning to the given comparator.

See page Mapping expressions (lambda).

Overview

plus(Collection)

Overview

plus(Object)

Overview

print

Overview

print(Object)

Overview

remove(int)

Overview

remove(Object)

Overview

removeAll(Collection)

Overview

retainAll(Collection)

Overview

reverse

Overview

set(int, Object)

Overview

set(String, Object)

Overview

size

Overview

sort

Overview

sort(String)

Overview

sort(Comparator)

Overview

sort(Lambda)

If lists have several attributes per element (comparable with a dataset with several columns), the elements can be sorted by the individual attributes using the method .sort(Lambda).

See page Mapping expressions (lambda).

Overview

subList(int)

Overview

subList(int, int)

Overview

sublist(int)

Overview

sublist(int, int)

Overview

toArray

Overview

toArray(Object[])

Overview

toJson

Overview

toString

Overview

toString(String)

The individual elements, e.g. of a list, can be output as string, separated by a delimiter which can be chosen freely.

Example:

$CMS_SET(myList, ["House","Key","Window"])$
$CMS_VALUE(myList.toString("; "))$

The elements of the list myList are output, separated each by semicolon and a space character:

House; Key; Window

Overview

toString(String, String)

Overview

type

Overview