snabbdom/thunk.js

var h = require('./h');

function init(thunk) {
  var i, cur = thunk.data;
  cur.vnode = cur.fn.apply(undefined, cur.args);
}

function prepatch(oldThunk, thunk) {
  var i, old = oldThunk.data, cur = thunk.data;
  var oldArgs = old.args, args = cur.args;
  cur.vnode = old.vnode;
  if (old.fn !== cur.fn || oldArgs.length !== args.length) {
    cur.vnode = cur.fn.apply(undefined, args);
    return;
  }
  for (i = 0; i < args.length; ++i) {
    if (oldArgs[i] !== args[i]) {
      cur.vnode = cur.fn.apply(undefined, args);
      return;
    }
  }
}

module.exports = function(name, fn /* args */) {
  var i, args = [];
  for (i = 2; i < arguments.length; ++i) {
    args[i - 2] = arguments[i];
  }
  return h('thunk' + name, {
    hook: {init: init, prepatch: prepatch},
    fn: fn, args: args,
  });
};