如何在Backbone.js v0.5中构建深度嵌套模型
假设每个A有0个或多个B,每个B有0个或多个C项。如何在Backbone.js(v0.5)中呈现这种关系。我想要像/A/A/B/B/C/C这样的URL。以下代码在coffeescript中。我很困惑,如何在下面的代码中设置url变量如何在Backbone.js v0.5中构建深度嵌套模型,backbone.js,Backbone.js,假设每个A有0个或多个B,每个B有0个或多个C项。如何在Backbone.js(v0.5)中呈现这种关系。我想要像/A/A/B/B/C/C这样的URL。以下代码在coffeescript中。我很困惑,如何在下面的代码中设置url变量 class As extends Backbone.Collection url: "/A" model: A class A extends Backbone.Model initialize: -> @Bs = ne
class As extends Backbone.Collection
url: "/A"
model: A
class A extends Backbone.Model
initialize: ->
@Bs = new Bs()
@Bs.parent=@
@Bs.url="/A/#{@id}"
class Bs extends Backbone.Collection
model: B
class B extends Backbone.Model
initialize: ->
@Cs = new Cs()
@Cs.url = ??? # => /A/a/B/b/C/
@Cs.parent=@
class Cs extends Backbone.Collection
model: C
class C extends Backbone.Model
url: #?? url => /A/a/B/b/C/c
我不会创建嵌套的URL,除非你真的有一个很好的理由。每个资源都可以由资源名称和id定义。对象之间的关系是内部的
http://foo.com/a/:id.json
http://foo.com/b/:id.json
http://foo.com/c/:id.json
也就是说,大量点击服务器以拉出嵌套对象并不是真正理想的。最好使用一个返回嵌套json的资源
http://foo.com/a/:id.json
例如,我从服务器返回的数据如下所示
{
"id": 372,
"context": "office_work",
"date_of_entry": "2011-7-05 15:22:00",
"blood_glucose_measurement": 98,
"food": {
"exchanges": "98",
"list": "burger fries"
},
"exercise": {
"duration": "28",
"list": "running shopping"
}
}
子节点由一个定制控制器组装,该控制器获取单个db记录并生成数据树
但是,您现在遇到了麻烦,因为backbone.js本机仅支持平面结构。我对基本主干模型做了一些修改,以支持处理树状结构
如果对你有用的话,我会把它贴在这里
#= require jquery
#= require underscore
#= require backbone
#
class RailsModel extends Backbone.Model
initialize: (attributes) ->
data = {}
for k,v of @attributes
if v.constructor.name == "Object"
data[k] = new RailsModel(v)
@set data, {silent: true}
get: (field)->
val = @
first = true
for p in field.split('/')
if first
val = super(p)
else
# This allows returning *undefined* rather
# than an exception if the parent of a deeply
# nested node does not exist.
val = if val? then val.get(p) else undefined
first = false
val
# Allow heirarchical setting of objects
#
# Example
#
# model.set_field('root/child', 10)
#
# Will create the path if it does not exist
set_field: (field, value, silent=false)->
path = field.split('/')
node = undefined
val = @
for p in field.split('/')
node = val
val = node.get(p)
if not val?
data = {}
val = new RailsModel
data[p] = val
node.set data
data = {}
data[p] = value
node.set data
if not silent and /\//.test(field)
@trigger("change:#{field}", @model, value)
@trigger("change", @model)
window.RailsModel = RailsModel
你可以像这样使用它
model = new RailsModel
model.url = "/data"
model.fetch()
model.get('excercise/duration')
model.set_field('excercise/duration', 25)
最后一行将触发事件“更改:练习/持续时间”