featureofinterest.go

package core

import (
	"encoding/json"
	"errors"
)

// FeatureOfInterest in SensorThings represents the phenomena an Observation is detecting. In some cases a FeatureOfInterest
// can be the Location of the Sensor and therefore of the Observation. A FeatureOfInterest is linked to a single Observation
type FeatureOfInterest struct {
	BaseEntity
	Name               string                 `json:"name,omitempty"`
	Description        string                 `json:"description,omitempty"`
	EncodingType       string                 `json:"encodingType,omitempty"`
	Feature            map[string]interface{} `json:"feature,omitempty"`
	NavObservations    string                 `json:"Observations@iot.navigationLink,omitempty"`
	Observations       []*Observation         `json:"Observations,omitempty"`
	OriginalLocationID interface{}            `json:"-"`
}

func (f *FeatureOfInterest) ClearNav() {
	f.NavSelf = ""
	f.NavObservations = ""
}

// GetEntityType returns the EntityType for FeatureOfInterest
func (f FeatureOfInterest) GetEntityType() EntityType {
	return EntityTypeFeatureOfInterest
}

// GetPropertyNames returns the available properties for a FeatureOfInterest
func (f *FeatureOfInterest) GetPropertyNames() []string {
	return []string{"id", "name", "description", "encodingType", "feature"}
}

// ParseEntity tries to parse the given json byte array into the current entity
func (f *FeatureOfInterest) ParseEntity(data []byte) error {
	foi := &f
	err := json.Unmarshal(data, foi)
	if err != nil {
		return errors.New("Unable to parse FeatureOfInterest")
	}

	return nil
}

// ContainsMandatoryParams checks if all mandatory params for a FeatureOfInterest are available before posting
func (f *FeatureOfInterest) ContainsMandatoryParams() (bool, []error) {
	err := []error{}
	CheckMandatoryParam(&err, f.Name, f.GetEntityType(), "name")
	CheckMandatoryParam(&err, f.Description, f.GetEntityType(), "description")
	CheckMandatoryParam(&err, f.EncodingType, f.GetEntityType(), "encodingType")
	CheckMandatoryParam(&err, f.Feature, f.GetEntityType(), "feature")

	if len(err) != 0 {
		return false, err
	}

	return true, nil
}

// SetAllLinks sets the self link and relational links
func (f *FeatureOfInterest) SetAllLinks(externalURL string) {
	f.SetSelfLink(externalURL)
	f.SetLinks(externalURL)

	for _, o := range f.Observations {
		o.SetAllLinks(externalURL)
	}
}

// SetSelfLink sets the self link for the entity
func (f *FeatureOfInterest) SetSelfLink(externalURL string) {
	f.NavSelf = CreateEntitySelfLink(externalURL, EntityLinkFeatureOfInterests.ToString(), f.ID)
}

// SetLinks sets the entity specific navigation links, empty string if linked(expanded) data is not nil
func (f *FeatureOfInterest) SetLinks(externalURL string) {
	f.NavObservations = CreateEntityLink(f.Observations == nil, externalURL, EntityLinkFeatureOfInterests.ToString(), EntityLinkObservations.ToString(), f.ID)
}