Roughing in characteristics

characteristics.go

@@ -0,0 +1,112 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"log"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/gorilla/mux"
+)
+
+func init() {
+	DB.AddTableWithName(CharacteristicBase{}, "characteristics").SetKeys(true, "Id")
+}
+
+// A Characteristic is a lookup type
+type CharacteristicBase struct {
+	Id                   int64     `json:"id,omitempty"`
+	CharacteristicName   string    `db:"characteristic_name" json:"characteristicName"`
+	CharacteristicTypeId int64     `db:"characteristic_type_id" json:"-"`
+	CreatedAt            time.Time `db:"created_at" json:"createdAt"`
+	UpdatedAt            time.Time `db:"updated_at" json:"updatedAt"`
+	DeletedAt            NullTime  `db:"deleted_at" json:"deletedAt"`
+}
+
+type Characteristic struct {
+	*CharacteristicBase
+	Measurements           NullSliceInt64 `db:"measurements" json:"measurements"`
+	Strains                NullSliceInt64 `db:"strains" json:"strains"`
+	CharacteristicTypeName string         `db:"characteristic_type_name" json:"characteristicType"`
+}
+
+type CharacteristicJSON struct {
+	Characteristic *Characteristic `json:"characteristic"`
+}
+
+type CharacteristicsJSON struct {
+	Characteristics []*Characteristic `json:"characteristics"`
+}
+
+type CharacteristicListOptions struct {
+	ListOptions
+	Genus string
+}
+
+func serveCharacteristicsList(w http.ResponseWriter, r *http.Request) {
+	var opt CharacteristicListOptions
+	if err := schemaDecoder.Decode(&opt, r.URL.Query()); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	opt.Genus = mux.Vars(r)["genus"]
+	log.Printf("%v", opt)
+
+	characteristics, err := dbGetCharacteristics(&opt)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if characteristics == nil {
+		characteristics = []*Characteristic{}
+	}
+	data, err := json.Marshal(CharacteristicsJSON{Characteristics: characteristics})
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json; charset=UTF-8")
+	w.Write(data)
+}
+
+func dbGetCharacteristics(opt *CharacteristicListOptions) ([]*Characteristic, error) {
+	if opt == nil {
+		return nil, errors.New("must provide options")
+	}
+	var vals []interface{}
+	sql := `SELECT c.*, ct.characteristic_type_name,
+			array_agg(m.id) AS measurements, array_agg(st.id) AS strains
+			FROM characteristics c
+			INNER JOIN characteristic_types ct ON ct.id=characteristic_type_id
+			LEFT OUTER JOIN measurements m ON m.characteristic_id=c.id
+			LEFT OUTER JOIN strains st ON st.id=m.strain_id
+			INNER JOIN species sp ON sp.id=st.species_id
+			INNER JOIN genera g ON g.id=sp.genus_id AND LOWER(g.genus_name)=$1`
+	vals = append(vals, opt.Genus)
+
+	if len(opt.Ids) != 0 {
+		var conds []string
+
+		c := "c.id IN ("
+		for i, id := range opt.Ids {
+			c = c + fmt.Sprintf("$%v,", i+2) // start param index at 2
+			vals = append(vals, id)
+		}
+		c = c[:len(c)-1] + ")"
+		conds = append(conds, c)
+		sql += " WHERE (" + strings.Join(conds, ") AND (") + ")"
+	}
+
+	sql += " GROUP BY c.id, ct.characteristic_type_name;"
+
+	var characteristics []*Characteristic
+	err := DBH.Select(&characteristics, sql, vals...)
+	if err != nil {
+		return nil, err
+	}
+	return characteristics, nil
+}

handlers.go

@@ -26,6 +26,9 @@ func Handler() http.Handler {
 	s.Handle("/measurements", authHandler(serveMeasurementsList)).Methods("GET")
 	s.Handle("/measurements/{Id:.+}", authHandler(serveMeasurement)).Methods("GET")
 
+	// Characteristics
+	s.Handle("/characteristics", authHandler(serveCharacteristicsList)).Methods("GET")
+
 	return corsHandler(m)
 }