How to avoid duplicate rendering of DOM elements in jsrender

问题

is it possible to check for duplicate Dom elements while rendering a jsrender.template?

For example:

1. if element doesnt exists use this:

   <li id="liv_{{:nid}}">
       <div class="qwqw"><a href="#"></a></div>
       <div class="">
           <p class="we">{{:spd}} <span>mph (todo)</span></p>
       </div>
   
       <div class="clear"></div>
     </li>
   

2. if the element "liv1" exists then update the view and dont perform step 1.

回答1:

Try to use helper functions

Templates pseudo code:

{{if ~domElementExists(id)}}
...
{{/if}}

Helper's pseudo code

$.views.helpers({

    domElementExists: function( id ) {

        return $("#liv_" + id).length > 0;

    }
});

来源：https://stackoverflow.com/questions/13018124/how-to-avoid-duplicate-rendering-of-dom-elements-in-jsrender