以编程方式添加的复合组件内的数据表 [英] Datatable inside programatically added composite component

问题描述

参考我之前的问题(以编程方式创建和添加复合支持 bean 中的组件) 我已经成功地从支持 bean 添加复合组件.现在我有一个新问题，因为其中包含惰性数据表的复合组件根本不调用 load() 方法.有关于此的错误报告(https://code.google.com/p/primefaces/issues/detail?id=3258) 但它被标记为与 PF3.0.RC1 相关，我不知道它是否已针对我正在使用的 3.5 版修复.

Referring to my earlier question (Programmatically create and add composite component in backing bean) I have succesfully able to add composite components from backing bean. Now I have a new problem as composite component with lazy datatable in it does not call load() method at all. There was bug report about this (https://code.google.com/p/primefaces/issues/detail?id=3258) but that is marked to be related to PF3.0.RC1 and I have no clue if it is fixed for version 3.5 I am using.

我正在使用与提到的 BalusC 完全相同的代码，可以向复合组件添加值表达式:

I am using the exactly same code BalusC mentioned with possibility to add value expressions to the composite component:

public void includeCompositeComponent(UIComponent parent, String libraryName, String resourceName, String id, Map<String, String> valueExpressions) {
    ...
    if (!valueExpressions.isEmpty()) {
        ExpressionFactory factory = application.getExpressionFactory();
        ELContext ctx = context.getELContext();
        for (Map.Entry<String, String> entry : valueExpressions.entrySet()) {
            ValueExpression expr = factory.createValueExpression(ctx, entry.getValue(), String.class);
            composite.setValueExpression(entry.getKey(), expr);
        }
    } 
    ...
}

这是我的复合组件 testDatatable.xhtml:

And this is my composite component testDatatable.xhtml:

<cc:interface>
    <composite:attribute name="model" required="true" type="org.primefaces.model.LazyDataModel"/>
    <composite:attribute name="id" default="dataTable"/>
</cc:interface>
<cc:implementation>
    <h:form id="dataTableForm">    
        <p:dataTable id="#{cc.attrs.id}" value="#{cc.attrs.model}" var="test" paginator="true" rows="10"
                     paginatorTemplate="{RowsPerPageDropdown} {FirstPageLink} {PreviousPageLink} {CurrentPageReport} {NextPageLink} {LastPageLink}"
                     rowsPerPageTemplate="5,10,15,20" lazy="true">
            <p:column>
                <h:outputText value="#{test.car.model}"/>
            </p:column>
         </p:dataTable>
    </h:form>
</cc:implementation>

这里是从支持 bean 创建复合组件:

And here is the creation of the composite component from backing bean:

Map<String, String> v = new HashMap<String, String>();
v.put("model", "#{testBean.lazyModel}");
addCompositeComponent(rootPanel, "comp", "testDatatable.xhtml", "table", v);

这是我在@PostConstruct 中加载的惰性数据模型

Here is the lazy data model I am loading in @PostConstruct

pulic class TestBean {
    private TestLazyDataModel<TestClass> lazyModel;

    @PostConstruct
    public void init() {
        lazyModel = new TestLazyDataModel();
    }

    public TestLazyDataModel<TestClass> getLazyModel() {
        return lazyModel;
    }

    class TestLazyDataModel extends LazyDataModel<TestClass> {
        @Override
        public List<TestClass> load(int first, int pageSize, String sort, SortOrder sortOrder, Map<String, String> filters) {
            List<TestClass> ret = new ArrayList<TestClass>();
            TestClass t = new TestClass();
            Car c = new Car("Volvo");
            t.setCar(c);
            ret.add(t);
            return ret;
        }
    }
}

还有一些辅助类:

public class TestClass {
    private Car car;

    public void setCar(Car car) {
        this.car = car;
    }

    public Car getCar() {
        return car;
    }
}

public class Car {
    public String model;

    public Car(String model) {
        this.model = model;
    }

    public String getModel() {
        return model;
    } 
}

总而言之，页面现在打开了:

In conclusion as the page is now opened:

1. bean 创建了惰性数据模型 ok
2. 从复合组件中正确获取惰性数据模型
3. 当数据表尝试遍历其中的项目时，出现错误:java.lang.String"类没有属性car"

将 <h:outputText value="#{test.car.model}"/> 更改为 <h:outputText value="#{test.class.name}"/> 也是 java.lang.String 但这次没有崩溃.调试时，TestLazyDataModel 的 load() 方法不会被调用.

Changing the <h:outputText value="#{test.car.model}"/> to <h:outputText value="#{test.class.name}"/> also java.lang.String but does not crash this time. When debugging this the load() method of the TestLazyDataModel is never called.

更奇怪的是，如果我使用来自任何其他 xhtml 页面的相同复合组件，例如:

Also to make this even weirder is that if I use the same composite component from any other xhtml page like:

<comp:testDatatable model="#{anotherBean.model}"> 

它工作正常.我错过了什么?这是否与组件的渲染顺序有关?非常感谢任何帮助！

it works fine. What am I missing? Is this related somehow to the rendering order of the components? Any help is highly appreciated!

推荐答案

刚刚开始工作.. 更改复合组件值表达式包括使用 Object.class 而不是 String.class 的代码:

Just got it to work.. Changing the composite component value expression include code to use Object.class instead String.class:

public void includeCompositeComponent(UIComponent parent, String libraryName, String resourceName, String id, Map<String, String> valueExpressions) {
    ...
    if (!valueExpressions.isEmpty()) {
        ExpressionFactory factory = application.getExpressionFactory();
        ELContext ctx = context.getELContext();
        for (Map.Entry<String, String> entry : valueExpressions.entrySet()) {
            ValueExpression expr = factory.createValueExpression(ctx, entry.getValue(), Object.class);
            composite.setValueExpression(entry.getKey(), expr);
        }
    } 
    ...
}

成功了.希望这对其他人也有帮助！

did the trick. Hope this helps someone else too!

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