使用新的数组元素更新backbone.js模型

Question

我有一个类似于下面所示的backbone.js模型.

Filters = Backbone.Model.extend({
    defaults : {
        title: [ ["title1", "easy"], ["title2", "hard"] ]
    }
});

我正在尝试向第一级数组添加一个元素,这样模型就变成了:

Filters = Backbone.Model.extend({
    defaults : {
        title: [ ["title1", "easy"], ["title2", "hard"], ["title3", "medium"] ]
    }
});

我现在的代码是这样的:

function setFilters() { 
    var options = {};   

    for (var facet in facets) {
        for (var facetKey in facets[facet]) {
            if (!filterExists(facetKey)) {
                options[facetKey] = new Array(new Array(facets[facet][facetKey], "equals"));
            }
            else {
                (filters[facetKey]).push(new Array(facets[facet][facetKey], "equals"));
            }
        }
    }

    filters.set(options);
}

函数filterExists只检查模型中是否存在键"title".当我运行它时,它说过滤器[facetKey]是未定义的.但这不是我需要将元素推入的第一级数组吗？

Answer 1

您可以使用.get()和.set()函数访问模型属性,也可以直接通过.attributes属性访问:

http://documentcloud.github.com/backbone/#Model-attributes

var filters = new Filters();
filters.attributes.facetKey.push( [...] );

要么

filters.set('facetKey', ( filters.get('facetKey') || []).concat([...]));

无论如何,这是你的转换函数,可能会或可能不会工作:

function setFilters() { 
    for (var facet in facets) {
        for (var facetKey in facets[facet]) {
            var f = [ facets[facet][facetKey], "equals" ];

            if( filterExists(facetKey)) {
            // OR: if( filters.attributes[ facetKey ]){
                filters.attributes[ facetKey ].push( f );
            }else{
                filters.attributes[ facetKey ] = [ f ];
            }
        }
    }

    // trigger change event for all attributes
    filters.set( filters.attributes );
}

奖金:

(filters.attributes[ facetKey ] = filters.attributes[ facetKey ] || [] ).push(f);