永久性dom-if的聚合物预计算

Question

Is there a way to pre-compute a polymer element based on a condition ? Let's say for every button, there is an admin button that opens a popup that has debug features. As the user will not dynamically become an admin, I'd like to pre-compile my polymer element to avoid the overhead of computing whether it should be displayed every time I insert a button.

It would probably look like

<dom-module id="a-very-common-button">
  <template>
    <div>
      <!-- Remove the button before it is inserted everywhere -->
      <button keep-if="window.isAdmin">
        button for admins
      </button>
      <button>regular button</button>
    </div>
  </template>
</dom-module>

Is it possible ?

Answer 1

Just to make sure you understand the implications - you realise that this is all in the client, putting admin content in there would be a severe security issue as anyone could set window.isAdmin=true.

Apart from that you could extend the native button element providing this function for every standard button. https://www.polymer-project.org/1.0/docs/devguide/registering-elements#type-extension