JSF组件ID中生成的前缀j_idt33是什么? [英] What's the generated prefix j_idt33 in JSF component id?

问题描述

我将h:messages组件定义如下:

i define h:messages component as follows:

<h:messages id="summary"  styleClass="summary" globalOnly="true"/>

但是当我用萤火虫检查元素时，我注意到id转换为类似以下内容:j_idt33:summary

but when i inspected element with firebug, i noticed that the id is translated to something like: j_idt33:summary

前缀是什么，为什么生成?

what's that prefix, and why it's generated ?

推荐答案

这是父级的ID

That's the ID of the parent NamingContainer component like <h:form>, <h:dataTable>, <ui:repeat>, <f:subview>, a composite component, etc.

JSF在生成的HTML客户机ID之前加上父namingcontainer组件的ID，以避免每当在生成的HTML输出中(例如在表行中)多次重复使用组件时，HTML客户机ID发生冲突.包含文件或复合组件等.拥有多个具有相同ID的HTML元素即是违法的.

JSF prepends the generated HTML client ID with the ID of the parent namingcontainer component in order to avoid clashes in the HTML client ID whenever a component is reused more than once in the generated HTML output, such as in a table row, or an include file, or a composite component, etc. It's namely illegal to have multiple HTML elements with the same ID.

您可以通过为NamingContainer组件提供固定的ID来抑制自动生成的ID.在您的特定情况下，很可能是<h:form>.因此，给它一个固定的ID，例如

You can suppress the autogenerated ID by giving the NamingContainer component a fixed ID. In your particular case, it's most likely the <h:form>. So give it a fixed ID, e.g.

<h:form id="form">
    ...

这样，j_idt33:summary将变为form:summary.

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