何时在 JSF 2.2 中使用资源库契约？

Question

我知道创建资源库合约是为了支持模板化，但即使没有它，也可以通过 template.xhtml 中的 ui:insert 轻松实现模板化：

<div id="content">
            <ui:insert name="content" />
</div>

可以在 Web 应用程序根目录下使用 'templates' 目录，而不是创建 "contracts" 目录。

那么，使用合同有什么好处？

Answer 1

要创建多个模板并将它们应用于同一应用程序的不同页面，还允许用户select他们想要应用的模板。

很好的例子Applying JSF 2.2 Resource Library Contracts

Answer 2

Well, you know, both the flows and the resource library contracts were obviously, big-ticket features. And a resource library contract is really, really powerful if you're in a situation where you want to support both mobile and a desktop client because you can just switch back and forth between a set of templates that you just define. So that is a really strong feature.

And hopefully, people see that. But the nice thing about it, it's a stackable feature. So what that means is you could actually have a resource library contract for a layout, and then a resource library contract on top of that for color styling or something like that. So you could switch back and forth between -- I'm just using an example, obviously -- a blue and a red styling, and a mobile versus desktop styling. So that would be four permutations that you would already have.

That's the other thing that jumps out at me because I've -- I'm sure you ran into this as well. I had clients who basically have a product that they sell, and either it's a hosted product or it's an on premise product. But either way, each client wants a different look and feel, and different sets of parameters, and things like that. And you can do a lot of that in the database, but at some point, you want to actually change the templates, and the resource library contracts makes that very easy to use. So I think that's one of my favorite features, too.

资源库合约允许您拥有多个资源库，这些资源库是在 JSF 2.0 中引入的，其中 css、js、图像和复合组件位于其中。

所有模板文件必须命名相同
全部<ui:inserts name="must have the same attribute value" />

有几种方法可以应用它。

-Web Pages/
--contracts/
---resource-1/
-----template.xhtml
-----css/
-----js/
-----img/
---resource-2/
-----template.xhtml
-----css/
-----js/
-----img/

#1：通过 URL 模式自动将合同映射到视图：

在faces-config.xml文件中

<application>

   <contract-mapping>
        <url-pattern>*</url-pattern>
        <contracts>resource-1</contracts>
   </contract-mapping>

   <contract-mapping>
        <url-pattern>/admin/*</url-pattern>
        <contracts>resource-2</contracts>
   </contract-mapping>

</application>

#2 设置每个视图的合同： 这允许用户select使用设计（模板）。

<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://xmlns.jcp.org/jsf/html"
      xmlns:ui="http://java.sun.com/jsf/facelets"
      xmlns:f="http://java.sun.com/jsf/core">

    <f:view contracts="#{templateMB.template}">
        <ui:composition template="/template.xhtml">
            <ui:define name="content">
                <h:form>
                    <h:selectOneMenu valueChangeListener="#{templateMB.tempEvent}"
                                     onchange="submit()">
                        <f:selectItem itemLabel="..." itemValue="..."/>
                        <f:selectItem itemLabel="resource-1" itemValue="resource-1"/>
                        <f:selectItem itemLabel="resource-2" itemValue="resource-2"/>
                    </h:selectOneMenu>
                </h:form>
            </ui:define>
        </ui:composition>
    </f:view>
</html>

托管bean所在位置：

@ManagedBean
@SessionScoped
public class TemplateMB {

    private String template = "resource-1"; // make default

    public TemplateMB() {
    }

    public void tempEvent(ValueChangeEvent e){
         template = (String) e.getNewValue();
    }

    public String getTemplate() {
        return template;
    }        
}

何时在 JSF 2.2 中使用资源库契约？

When to use Resource Library Contract in JSF 2.2?

jsf

templates

jsf-2.2