如果对象为nil，则在模板中显示默认内容，否则根据set属性显示 [英] Show default content in a template if an object is nil otherwise show based on the set property

问题描述

在我的模板中，我想包含一些默认的 meta 标记(90％的时间).但是，设置了特定属性后，我想显示另一组文本.

In my template, I would like to include some default meta tags (90% of the time). However, when a specific property is set, I would like to show a different set of text.

我知道我可以设置一个匿名 struct 并使用"default" 或"some-x" 设置属性.但是，这意味着，我需要向当前仅通过 nil 传递的90％的处理程序中添加一个匿名结构.

I know I can set an anonymous struct and set a property with either "default" or "some-x". However, this means, I need to add an anonymous struct to 90% of my handlers that just currently pass nil.

有没有办法做类似的事情

Is there way to do something like

{{if eq . nil}} 
   // default meta tag
{{else if eq .MetaValue "some-x"}} 
   //other
{{end}}

如果我尝试类似上面的代码，它将编译但不能执行我想要的操作.赞赏有关如何正确处理它的建议，而无需增加很多样板.

If I try something like my above code, it compiles but doesn't do what I want. Appreciate any suggestions on how to handle it properly without adding a lot of boiler plate.

谢谢！

推荐答案

{{if not .}}
   output when . is nil or otherwise empty including
     false, 0, and any array, slice, map, or string of length zero
{{else if eq .MetaValue "some-x"}}
       // some-x case
{{else}} 
       // other case
{{end}}

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