嵌套的 RESTful 资源 [英] nested RESTful resources

问题描述

我正在使用 Grails 在 2.3 中引入的对 REST 的支持.我的应用包括以下域类:

I'm using the support for REST introduced by Grails in 2.3. My app includes the following domain classes:

@Resource(formats=['json', 'xml'])
class Sensor {
    String name
    static hasMany = [metrics: Metric]
}

@Resource(formats=['json', 'xml'])
class Metric {

    String name
    String value

    static belongsTo = [sensor: Sensor]
}

在 UrlMappings.groovy 中，我定义了以下嵌套的 RESTful URL 映射:

And in UrlMappings.groovy I've defined the following nested RESTful URL mappings:

"/api/sensors"(resources: 'sensor') {
    "/metrics"(resources: "metric")
}

如果我导航到 URL /api/sensors/1/metrics 我希望响应显示与 SensorMetric 实例> ID 为 1，但实际上它返回所有 Metric 实例(最多 10 个)

If I navigate to the URL /api/sensors/1/metrics I expect the response to show all Metric instances associated with the Sensor with ID 1, but in fact it returns all Metric instances (up to a limit of 10)

• 是否有一个 URL 将仅返回与特定 Sensor 实例相关联的 Metric 实例(不实现我自己的控制器)?
• 有没有办法覆盖 10 个结果的默认限制(不向请求添加 max 参数)?

• Is there a URL that will return only Metric instances associated with a particular Sensor instance (without implementing my own controller)?
• Is there a way to override the default limit of 10 results (without adding a max parameter to the request)?

推荐答案

看起来没那么简单.:) 如果运行这个命令，我们可以得到一个生动的画面:

Looks like it isn't that simple. :) We can get a vivid picture if this command is run:

grails url-mapping-report

去看

Controller: metric
 |   GET    | /api/sensors/${sensorId}/metrics           | Action: index  |
 |   GET    | /api/sensors/${sensorId}/metrics/create    | Action: create |
 |   POST   | /api/sensors/${sensorId}/metrics           | Action: save   |
 |   GET    | /api/sensors/${sensorId}/metrics/${id}     | Action: show   |
 |   GET    | /api/sensors/${sensorId}/metrics/${id}/edit| Action: edit   |
 |   PUT    | /api/sensors/${sensorId}/metrics/${id}     | Action: update |
 |  DELETE  | /api/sensors/${sensorId}/metrics/${id}     | Action: delete |

所以，我们至少需要一个 MetricController 继承 RestfulController 并覆盖 index() 来对 Metric 做额外的检查 和基于 Sensor 的返回列表如下所示:

So, we would at least need a MetricController inheriting RestfulController and override index() to do an additional check for Metric and return list based on Sensor as shown below:

class MetricController extends RestfulController<Metric> {
    static responseFormats = ['json', 'xml']

    MetricController() {
        super(Metric)
    }

    @Override
    def index() {
        def sensorId = params.sensorId
        respond Metric.where {
            sensor.id == sensorId
        }.list()
    }
}

以上更改将在点击时为 /api/sensors/1/metrics 提供预期结果(包括对分页结果的限制).

Above changed would provide the expected result (including the restriction on paginated results) for /api/sensors/1/metrics when hit.

这篇关于嵌套的 RESTful 资源的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！