Merge pull request #2 from qri-io/orderby-util

feat(orderby): added util for orderBy support in api calls

order.go

@@ -0,0 +1,110 @@
+package apiutil
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+var (
+	// OrderASC defines the ascending order keyword
+	OrderASC = "asc"
+	// OrderDESC defines the descending order keyword
+	OrderDESC = "desc"
+)
+
+// OrderBy represents ordering information
+type OrderBy []Order
+
+// Order represents ordering information for a single key
+type Order struct {
+	Key       string
+	Direction string
+}
+
+// NewOrder constructs a basic order struct
+func NewOrder(key, orderDirection string) Order {
+	if orderDirection != OrderASC && orderDirection != OrderDESC {
+		orderDirection = OrderDESC
+	}
+	return Order{
+		Key:       key,
+		Direction: orderDirection,
+	}
+}
+
+// String implements the stringer interface for OrderBy
+func (o OrderBy) String() string {
+	var b strings.Builder
+	for i, oi := range o {
+		if i > 0 {
+			b.WriteString(",")
+		}
+		b.WriteString(oi.String())
+	}
+	return b.String()
+}
+
+// String implements the stringer interface for Order
+func (o Order) String() string {
+	return fmt.Sprintf("%s,%s", o.Key, o.Direction)
+}
+
+// SetQueryParams adds order by info to a url as query parameters
+func (o OrderBy) SetQueryParams(u *url.URL) *url.URL {
+	q := u.Query()
+	if len(o) > 0 {
+		q.Set("orderBy", o.String())
+	}
+
+	u.RawQuery = q.Encode()
+	return u
+}
+
+// OrderByFromRequest extracts orderBy params from an http request
+func OrderByFromRequest(r *http.Request) OrderBy {
+	orderBy := r.FormValue("orderBy")
+	return NewOrderByFromString(orderBy, nil)
+}
+
+// OrderByFromRequestWithKeys extracts orderBy params from an
+// http request and only takes the specified keys
+func OrderByFromRequestWithKeys(r *http.Request, validKeys []string) OrderBy {
+	orderBy := r.FormValue("orderBy")
+	return NewOrderByFromString(orderBy, validKeys)
+}
+
+// NewOrderByFromString converts a commaa delimited string to an OrderBy struct
+func NewOrderByFromString(orderBy string, validKeys []string) OrderBy {
+	orderComponents := strings.Split(orderBy, ",")
+	if orderBy == "" || len(orderComponents) == 0 || (len(orderComponents) != 1 && len(orderComponents)%2 == 1) {
+		return []Order{}
+	}
+	res := []Order{}
+	if len(orderComponents) == 1 {
+		res = append(res, NewOrder(strings.TrimSpace(orderComponents[0]), OrderDESC))
+		return res
+	}
+	for i := 0; i <= len(orderComponents)/2; i += 2 {
+		orderDirection := ""
+		if strings.ToLower(orderComponents[i+1]) == OrderASC {
+			orderDirection = OrderASC
+		} else {
+			orderDirection = OrderDESC
+		}
+		orderKey := strings.TrimSpace(orderComponents[i])
+		if validKeys != nil {
+			for _, vkey := range validKeys {
+				if vkey == orderKey {
+					res = append(res, NewOrder(orderKey, orderDirection))
+					break
+				}
+			}
+		} else {
+			res = append(res, NewOrder(orderKey, orderDirection))
+		}
+	}
+
+	return res
+}

order_test.go

@@ -0,0 +1,43 @@
+package apiutil
+
+import (
+	"net/http/httptest"
+	"testing"
+)
+
+func TestOrderByFromRequest(t *testing.T) {
+	cases := []struct {
+		description string
+		query       string
+		validKeys   []string
+		expNumber   int
+		expOrderBy  string
+	}{
+		{"no orderBy specified", "", nil, 0, ""},
+		{"orderBy with no direction (defaults to desc)", "title", nil, 1, "title,desc"},
+		{"invalid orderBy", "title,asc,date", nil, 0, ""},
+		{"orderBy with bad parameters", "title,asc, date,desc", nil, 2, "title,asc,date,desc"},
+		{"orderBy with multiple parameters", "title,asc,date,desc", nil, 2, "title,asc,date,desc"},
+		{"orderBy with some invalid parameters", "title,asc,date,desc", []string{"title"}, 1, "title,asc"},
+	}
+
+	for _, c := range cases {
+		r := httptest.NewRequest("GET", "/", nil)
+		q := r.URL.Query()
+		// add query params
+		if c.query != "" {
+			q.Set("orderBy", c.query)
+		}
+
+		r.URL.RawQuery = q.Encode()
+
+		got := OrderByFromRequestWithKeys(r, c.validKeys)
+		if c.expNumber != len(got) {
+			t.Errorf("case '%s' error: number mismatch, expected '%d', got '%d'", c.description, c.expNumber, len(got))
+		}
+		if c.expOrderBy != got.String() {
+			t.Errorf("case '%s' error: output mismatch, expected '%s', got '%s'", c.description, c.expOrderBy, got.String())
+		}
+	}
+
+}