javascript - knockout template - binding text to a function, with template data passed in -

i have view model observable array. populated json:

this.socialtiles = ko.observablearray([]);  ko.computed(function () {    jquery.getjson( this.apiurl+"&callback=?", function (data) {      var thedata = data.entries;      tilesmodel.socialtiles(thedata);     console.dir(thedata);   }); }, tilesmodel); 

for each item in model, build li using template:

<ul id="tiles-ul" data-bind="template: {name:'twitter_template', foreach:socialtiles}">    <script type="text/html" id="twitter_template">    <li class="social-tile box-shadow">     <div class="header">       <div class="header-img">         <img data-bind="attr: { src: actor.avatar}">       </div>       <div class="name_and_time">         <span class="full-name" data-bind="text: actor.title"></span>         <span class="twitter-name" data-bind="text: actor.id"></span>         <span class="how-long-ago" > 5 minutes ago </span>       </div>     </div>     <div class="message-content" data-bind="html: object.content">     </div>     <div class="footer">       <div class="social-icon-twitter">       </div>     </div>        <span data-bind="text: $index"></span>         </li>    </script> 

id data-bind text of element result of function, current data model used argument . example:

actor.id string containing twitter url of user (like "http://twitter.com/iamdiddy")

i'd pass string function , return "#iamdiddy" representation.

<span class="twitter-name" data-bind="text: gettwittertag(actor.id)"></span> 

in view model

 function gettwittertag("twurl"){     return ... whatever; } 

how can (call function argument, not extract #... )? knockout support functionality?

try changing

<span class="twitter-name" data-bind="text: gettwittertag(actor.id)"></span> 

to

<span class="twitter-name" data-bind="text: $root.gettwittertag($data)"></span>