Files
edx-platform/lms/static/js/discovery/models/search_state.js
2016-08-05 15:29:20 -04:00

147 lines
5.0 KiB
JavaScript

(function(define) {
define([
'underscore',
'backbone',
'js/discovery/models/course_discovery',
'js/discovery/collections/filters'
], function(_, Backbone, CourseDiscovery, Filters) {
'use strict';
return Backbone.Model.extend({
page: 0,
pageSize: 20,
searchTerm: '',
terms: {},
jqhxr: null,
initialize: function() {
this.discovery = new CourseDiscovery();
this.listenTo(this.discovery, 'sync', this.onSync, this);
this.listenTo(this.discovery, 'error', this.onError, this);
},
performSearch: function(searchTerm, otherTerms) {
this.reset();
this.searchTerm = searchTerm;
if (otherTerms) {
this.terms = otherTerms;
}
this.sendQuery(this.buildQuery(0));
},
refineSearch: function(terms) {
this.reset();
this.terms = terms;
this.sendQuery(this.buildQuery(0));
},
loadNextPage: function() {
if (this.hasNextPage()) {
this.sendQuery(this.buildQuery(this.page + 1));
}
},
// private
hasNextPage: function() {
var total = this.discovery.get('totalCount');
return total - ((this.page + 1) * this.pageSize) > 0;
},
sendQuery: function(data) {
this.jqhxr && this.jqhxr.abort();
this.jqhxr = this.discovery.fetch({
type: 'POST',
data: data
});
return this.jqhxr;
},
buildQuery: function(pageIndex) {
var data = {
search_string: this.searchTerm,
page_size: this.pageSize,
page_index: pageIndex
};
_.extend(data, this.terms);
return data;
},
reset: function() {
this.discovery.reset();
this.page = 0;
},
onError: function(collection, response, options) {
if (response.statusText !== 'abort') {
this.trigger('error');
}
},
onSync: function(collection, response, options) {
var total = this.discovery.get('totalCount');
var originalSearchTerm = this.searchTerm;
if (options.data.page_index === 0) {
if (total === 0) {
// list all courses
this.cachedDiscovery().done(function(cached) {
this.discovery.courseCards.reset(cached.courseCards.toJSON());
this.discovery.facetOptions.reset(cached.facetOptions.toJSON());
this.discovery.set('latestCount', cached.get('latestCount'));
this.trigger('search', originalSearchTerm, total);
});
this.searchTerm = '';
this.terms = {};
}
else {
_.each(this.terms, function(term, facet) {
if (facet !== 'search_query') {
var option = this.discovery.facetOptions.findWhere({
facet: facet,
term: term
});
if (option) {
option.set('selected', true);
}
}
}, this);
this.trigger('search', this.searchTerm, total);
}
}
else {
this.page = options.data.page_index;
this.trigger('next');
}
},
// lazy load
cachedDiscovery: function() {
var deferred = $.Deferred();
var self = this;
if (this.cached) {
deferred.resolveWith(this, [this.cached]);
}
else {
this.cached = new CourseDiscovery();
this.cached.fetch({
type: 'POST',
data: {
search_string: '',
page_size: this.pageSize,
page_index: 0
},
success: function(model, response, options) {
deferred.resolveWith(self, [model]);
}
});
}
return deferred.promise();
}
});
});
})(define || RequireJS.define);