javascript Polymer 1.0：帮助使用 dom-if
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Polymer 1.0: Help using dom-if
提问by Let Me Tink About It
Can someone please provide an example of proper implementation of dom-if?
有人可以提供一个正确实施的例子dom-if吗？
No example of proper usage is provided by the official documentation. (Sorry there is no direct link. Must use menu in upper left and select dom-if).
官方文档没有提供正确使用的示例。（抱歉没有直接链接。必须使用左上角的菜单并选择dom-if）。
Here is what I have so far. Obviously, it is not working.
这是我到目前为止所拥有的。显然，它不起作用。
<template>
...
<template is="dom-if" if="{{action}}=='Login'">
<!-- Also tried: if="{{action=='Login'}}" -->
<a href="#">Forgot password?</a>
</template>
...
</template>
回答by agektmr
It's cumbersome, but you have to do this:
这很麻烦，但你必须这样做：
<template is="dom-if" if="[[_actionIsLogin(action)]]">
<a href="#">Forgot password?</a>
</template>
<script>
Polymer({
...
_actionIsLogin: function(action) {
return action === 'Login';
}
...
});
</script>
Explicitly create a function that returns either trueor false.
显式创建一个返回true或的函数false。
回答by Zohar81
i think that the following example is pretty much straight forward and easy to understand/implement (it's not in the link you've provided):
我认为以下示例非常直接且易于理解/实现（它不在您提供的链接中）：
https://www.polymer-project.org/1.0/docs/devguide/templates.html
https://www.polymer-project.org/1.0/docs/devguide/templates.html
from the page ...
从页面...
<div>{{user.name}}</div>
<template is="dom-if" if="{{user.isAdmin}}">
Only admins will see this.
<div>{{user.secretAdminStuff}}</div>
</template>
...
hope it helps.
希望能帮助到你。
回答by Cesar SC
<template>
<iron-ajax
auto
url="https://jsonplaceholder.typicode.com/todos"
handle-as="json"
last-response="{{baul}}">
</iron-ajax>
<template is="dom-repeat" items="{{baul}}" >
<template is="dom-if" if="{{item.completed}}">{{item.title}} is completed<br></template>
</template>
</template>
