define([], function () { return function () { var targets = [] var filterObservers = [] var filters = [] var filteredData var data function remove(d) { targets = targets.filter( function (e) { return d !== e } ) } function add(d) { targets.push(d) if (filteredData !== undefined) d.setData(filteredData) } function setData(d) { data = d refresh() } function refresh() { if (data === undefined) return filteredData = filters.reduce( function (a, f) { return f.run(a) }, data) targets.forEach( function (t) { t.setData(filteredData) }) } function notifyObservers() { filterObservers.forEach( function (d) { d.filtersChanged(filters) }) } function addFilter(d) { filters.push(d) notifyObservers() d.setRefresh(refresh) refresh() } function removeFilter(d) { filters = filters.filter( function (e) { return d !== e } ) notifyObservers() refresh() } function watchFilters(d) { filterObservers.push(d) d.filtersChanged(filters) return function () { filterObservers = filterObservers.filter( function (e) { return d !== e }) } } return { add: add, remove: remove, setData: setData, addFilter: addFilter, removeFilter: removeFilter, watchFilters: watchFilters, refresh: refresh } } })