“用于"在JSF中循环 [英] "for" cycle in JSF

问题描述

我只需要在JSF/ICEFaces中执行一个非常基本的for循环，基本上就是显示列号

I simply need to perform a very basic for cycle in JSF/ICEFaces, basically rendering column numbers

类似下面的伪代码

for(int i=0; i<max; i++)
{
   <td>#{i}</td>
}

<c:forEach>标记遍历集合，但是我不想让我的后备bean更复杂，返回一个愚蠢的整数集合.

the <c:forEach> tag iterates over collections, but I don't want to make my backing bean more complex returning a stupid collection of integers.

您知道更短更聪明的方法吗?

Do you know a shorter and smarter way?

谢谢

推荐答案

<ui:repeat>标记是您真正应该使用的标记. JSTL标记在JSF生命周期之外运行. Cay Horstman的JSF课程讨论了这个事实: ui:repeat和处理 可变长度数据.

The <ui:repeat> tag is what you should really use. The JSTL tags operate outside of the JSF Lifecycle. Cay Horstman has a JSF coursewhich discusses this fact: ui:repeat and Handling Variable-Length Data.

下面提供了一些解决方案，这些解决方案显示出一定的灵活性.您可以执行以下操作:

There are a couple of solutions below which demonstrate some flexibility. You could do something like this:

<ui:param name="max" value="5"/>
<ui:repeat var="i" value="#{indexBean.values}" size="#{max}" >
 <tr><td>#{i}</td></tr>
</ui:repeat>

最大行数由名为max的<ui:parameter>确定.这不是必需的，但确实显示了灵活性.或者，您可以使用类似以下内容的

The maximum number of rows is determined by a a <ui:parameter> named max. This is not required, but does demonstrate flexibility. Alternatively you could use something like:

<ui:param name="max" value="5"/>
<ui:repeat var="i" value="#{indexBean.rowNumbers(max)}">
 <tr><td>#{i}</td></tr>
</ui:repeat>

后备bean代码如下:

The backing bean code is the following:

@ManagedBean
public class IndexBean {

public List<Integer> getValues() {
    List<Integer> values = new ArrayList<Integer>();
    for (int i = 0; i < 10; i++) {
        values.add(i);
    }
    return values;
}

public List<Integer> rowNumbers(final int max) {
    List<Integer> values = new ArrayList<Integer>();
    for (int i = 0; i < max; i++) {
        values.add(i);
    }
    return values;
}
}

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