phoxy/ENJS

<%
/* Purpose: chaining efects on target design
 * Usage:
 *   __this.CascadeDesign('snippets/chain', obj);
 * Where object is:
 * {
 *   chain: [a,b,c]
 *   data: d
 * }
 *  b, c - effects that would be applied to a
 *  a - target design, that would be rendered last
 * How it done:
 *   All effects registering as chain elements, and when
 *   last element rendered, chain unrolling with calling
 *   handlers. All effect MUST call this.chain() once
 * Effect example:
 *   __this.chain(function()
 *   {
 *     this.first(); // <-- first DOM element of target design
 *     __this.first(); // <-- first DOM element of current chain
 *   })
 * Requirments:
 *   ENJS isolation depth more on equal than 3
 */

var child_context = null;

// Helper functions
function chain(decorator)
{ // Unroll the chain function. Reshedule remain tasks
  var context = this;

  context.CascadeDesign(child_context.design, child_context.data, function snippets_chain_payload_context_shorcut()
  {
    child_context.up(this);
    if (typeof decorator == 'function')
      decorator.apply(this, arguments);
  })
}

function CallbackEndOfChain()
{ // Copy current context and share it with all other chains
  ShareContextToNext(this);
}

function ShareContextToNext(context)
{ // Share context to next
  context.escape = __this.escape;
  __this.escape().across = context;
}




if (typeof __this.chain != 'object')
  return phoxy.Log(2, "Empty chain");

/* Get first tast, and if it not empty generate chain sequence
 */


var task = __this.chain.pop();
if (!__this.chain.length) // if last one, direct render and exit
  return __this.CascadeDesign(task, __this.data, CallbackEndOfChain);
else
{
  var chain_snippet_location = __this.escape().name.replace(phoxy.Config().ejs_dir, "");

  child_context =
  {
    design: chain_snippet_location,
    data: __this,
    up: ShareContextToNext,
  };

  var payload_context =
  {
    comment: "You will get valid context at chain callback. Please use __this.chain()",
    chain: chain,
    data: __this.data,
  }

  __this.CascadeDesign(task, payload_context);
}
%>