org.omnifaces.el.functions.Arrays Maven / Gradle / Ivy
/*
* Copyright 2012 OmniFaces.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
*/
package org.omnifaces.el.functions;
/**
*
* Collection of EL functions for array manipulation: of:createArray(), of:createIntegerArray(),
* and of:contains().
*
* @author Bauke Scholtz
*/
public final class Arrays {
// Constants ------------------------------------------------------------------------------------------------------
private static final String ERROR_INVALID_ARRAY_SIZE = "The array size must be at least 0.";
// Constructors ---------------------------------------------------------------------------------------------------
private Arrays() {
// Hide constructor.
}
// Utility --------------------------------------------------------------------------------------------------------
/**
* Creates and returns a dummy object array of the given size. This is useful if you want to iterate n times
* over an <ui:repeat>, which doesn't support EL in begin and end
* attributes.
* @param size The size of the dummy object array.
* @return A dummy object array of the given size.
* @throws IllegalArgumentException When the size is less than 0.
*/
public static Object[] createArray(int size) {
if (size < 0) {
throw new IllegalArgumentException(ERROR_INVALID_ARRAY_SIZE);
}
return new Object[size];
}
/**
* Creates and an integer array which starts at the given integer and ends at the given integer, inclusive. This is
* useful if you want to for example populate a <f:selectItems> which shows an integer range to
* represent days and years. If the begin is greater than end, then the array will be decremental. If the begin
* equals end, then the array will contain only one item.
* @param begin The begin integer.
* @param end The end integer.
* @return An integer array which starts at the given integer and ends at the given integer, inclusive
*/
public static Integer[] createIntegerArray(int begin, int end) {
int direction = (begin < end) ? 1 : (begin > end) ? -1 : 0;
int size = Math.abs(end - begin) + 1;
Integer[] array = new Integer[size];
for (int i = 0; i < size; i++) {
array[i] = begin + (i * direction);
}
return array;
}
/**
* Returns true if the string representation of an item of the given array equals to the string
* representation of the given item. This returns false if either the array or the item is null. This
* is useful if you want to for example check if #{paramValues.foo} contains a certain value.
* @param array The array whose items have to be compared.
* @param item The item to be compared.
* @return true if the string representation of an item of the given array equals to the string
* representation of the given item.
*/
public static boolean contains(Object[] array, Object item) {
if (array == null || item == null) {
return false;
}
for (Object object : array) {
if (object != null && object.toString().equals(item.toString())) {
return true;
}
}
return false;
}
}