Question

我有ActiveAdmin的过滤器来按用户的电子邮件过滤结果，并仅为特定用户返回结果：

  filter :user, :collection => proc { User.all.map { |i| [ i.to_s, i.id ] } }

现在我想添加选项以从结果中排除特定用户。

我该怎么做？

感谢。

Answer 1

我通过在相关模型中添加搜索方法和范围来解决它：

package main

import (
    "crypto/tls"
    "crypto/x509"
    "fmt"
    "io/ioutil"
    "strings"
    "time"

    MQTT "git.eclipse.org/gitroot/paho/org.eclipse.paho.mqtt.golang.git"
    "linksmart.eu/lc/core/catalog"
    "linksmart.eu/lc/core/catalog/service"
)

// MQTTConnector provides MQTT protocol connectivity
type MQTTConnector struct {
    config        *MqttProtocol
    clientID      string
    client        *MQTT.Client
    pubCh         chan AgentResponse
    subCh         chan<- DataRequest
    pubTopics     map[string]string
    subTopicsRvsd map[string]string // store SUB topics "reversed" to optimize lookup in messageHandler
}

const defaultQoS = 1

func (c *MQTTConnector) start() {
    logger.Println("MQTTConnector.start()")

    if c.config.Discover && c.config.URL == "" {
        err := c.discoverBrokerEndpoint()
        if err != nil {
            logger.Println("MQTTConnector.start() failed to start publisher:", err.Error())
            return
        }
    }

    // configure the mqtt client
    c.configureMqttConnection()

    // start the connection routine
    logger.Printf("MQTTConnector.start() Will connect to the broker %v\n", c.config.URL)
    go c.connect(0)

    // start the publisher routine
    go c.publisher()
}

// reads outgoing messages from the pubCh und publishes them to the broker
func (c *MQTTConnector) publisher() {
    for resp := range c.pubCh {
        if !c.client.IsConnected() {
            logger.Println("MQTTConnector.publisher() got data while not connected to the broker. **discarded**")
            continue
        }
        if resp.IsError {
            logger.Println("MQTTConnector.publisher() data ERROR from agent manager:", string(resp.Payload))
            continue
        }
        topic := c.pubTopics[resp.ResourceId]
        c.client.Publish(topic, byte(defaultQoS), false, resp.Payload)
        // We dont' wait for confirmation from broker (avoid blocking here!)
        //<-r
        logger.Println("MQTTConnector.publisher() published to", topic)
    }
}


func (c *MQTTConnector) stop() {
    logger.Println("MQTTConnector.stop()")
    if c.client != nil && c.client.IsConnected() {
        c.client.Disconnect(500)
    }
}

func (c *MQTTConnector) connect(backOff int) {
    if c.client == nil {
        logger.Printf("MQTTConnector.connect() client is not configured")
        return
    }
    for {
        logger.Printf("MQTTConnector.connect() connecting to the broker %v, backOff: %v sec\n", c.config.URL, backOff)
        time.Sleep(time.Duration(backOff) * time.Second)
        if c.client.IsConnected() {
            break
        }
        token := c.client.Connect()
        token.Wait()
        if token.Error() == nil {
            break
        }
        logger.Printf("MQTTConnector.connect() failed to connect: %v\n", token.Error().Error())
        if backOff == 0 {
            backOff = 10
        } else if backOff <= 600 {
            backOff *= 2
        }
    }

    logger.Printf("MQTTConnector.connect() connected to the broker %v", c.config.URL)
    return
}

func (c *MQTTConnector) onConnected(client *MQTT.Client) {
    // subscribe if there is at least one resource with SUB in MQTT protocol is configured
    if len(c.subTopicsRvsd) > 0 {
        logger.Println("MQTTPulbisher.onConnected() will (re-)subscribe to all configured SUB topics")

        topicFilters := make(map[string]byte)
        for topic, _ := range c.subTopicsRvsd {
            logger.Printf("MQTTPulbisher.onConnected() will subscribe to topic %s", topic)
            topicFilters[topic] = defaultQoS
        }
        client.SubscribeMultiple(topicFilters, c.messageHandler)
    } else {
        logger.Println("MQTTPulbisher.onConnected() no resources with SUB configured")
    }
}

func (c *MQTTConnector) onConnectionLost(client *MQTT.Client, reason error) {
    logger.Println("MQTTPulbisher.onConnectionLost() lost connection to the broker: ", reason.Error())

    // Initialize a new client and reconnect
    c.configureMqttConnection()
    go c.connect(0)
}

func (c *MQTTConnector) configureMqttConnection() {
    connOpts := MQTT.NewClientOptions().
        AddBroker(c.config.URL).
        SetClientID(c.clientID).
        SetCleanSession(true).
        SetConnectionLostHandler(c.onConnectionLost).
        SetOnConnectHandler(c.onConnected).
        SetAutoReconnect(false) // we take care of re-connect ourselves

    // Username/password authentication
    if c.config.Username != "" && c.config.Password != "" {
        connOpts.SetUsername(c.config.Username)
        connOpts.SetPassword(c.config.Password)
    }

    // SSL/TLS
    if strings.HasPrefix(c.config.URL, "ssl") {
        tlsConfig := &tls.Config{}
        // Custom CA to auth broker with a self-signed certificate
        if c.config.CaFile != "" {
            caFile, err := ioutil.ReadFile(c.config.CaFile)
            if err != nil {
                logger.Printf("MQTTConnector.configureMqttConnection() ERROR: failed to read CA file %s:%s\n", c.config.CaFile, err.Error())
            } else {
                tlsConfig.RootCAs = x509.NewCertPool()
                ok := tlsConfig.RootCAs.AppendCertsFromPEM(caFile)
                if !ok {
                    logger.Printf("MQTTConnector.configureMqttConnection() ERROR: failed to parse CA certificate %s\n", c.config.CaFile)
                }
            }
        }
        // Certificate-based client authentication
        if c.config.CertFile != "" && c.config.KeyFile != "" {
            cert, err := tls.LoadX509KeyPair(c.config.CertFile, c.config.KeyFile)
            if err != nil {
                logger.Printf("MQTTConnector.configureMqttConnection() ERROR: failed to load client TLS credentials: %s\n",
                    err.Error())
            } else {
                tlsConfig.Certificates = []tls.Certificate{cert}
            }
        }

        connOpts.SetTLSConfig(tlsConfig)
    }

    c.client = MQTT.NewClient(connOpts)
}

到控制器：

  search_methods :user_exclude_eq
  scope :user_exclude_eq,  lambda {|user| where('user_id != ?', user)}

ActiveAdmin过滤器按输入排除结果

1 个答案: