Grails:从 g:if 标签调用 taglib [英] Grails: Call taglib from g:if tag

问题描述

我有一个自定义标签库，它返回一个布尔对象，以便我的 GSP 可以决定是否显示一段 html.我想使用 g:if 标签来检查这个布尔值的值，因为我还需要检查一些其他值(在 taglib 中是不可访问的).但是，我不知道如何从标签中实际调用 taglib?

I have a custom tag lib that returns a Boolean object so that my GSP can decide whether to display a piece of html or not. I would like to use the g:if tag to check this Boolean's value since I also need to check a few other values (that aren't accesible in the taglib). However, I don't know how to actually call the taglib from the tag?

我试过了:

<g:if test="${<custom:tag/> && other.boolean}">

但这会引发错误.

我也试过:

<g:if test="<custom:tag/> && ${other.boolean}">

但这也会引发错误.

推荐答案

taglib 是什么样子的?看看它的用法应该如下:

How does the taglib look like? Looking at the usage it should be as below:

class SomeTagLib {
    static namespace = "custom"
    static returnObjectForTags = ['tag']

    def tag = { attrs, body ->
        //returns an object (can be boolean)
    }
}

默认情况下，标签库会返回 流字符缓冲区.如果您需要返回一个对象(如在您的情况下用作条件语句的一部分)，我想您需要 returnObjectFromTags 如上所示.它指定哪个标签偏离默认行为并返回一个对象.

By default, taglibs would return StreamCharBuffer. If you need an object to be returned, (as in your case to be used as part of conditional statement), I guess you would need returnObjectFromTags as shown above. It specifies which tag deviates from default behavior and returns an object instead.

此外，您应该使用 Tim 提到的 taglib:

Also, you should be using the taglib as mentioned by Tim:

<g:if test="${custom.tag() && other.boolean}"> //should be the appropriate way

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