added simple sql filter string parser/generator

Marko Tikvić
1 parent feb3471e7a
Showing 1 changed file with 76 additions and 0 deletions Show diff stats
filtering.go
@@ -0,0 +1,76 @@
+package webutility
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+)
+
+type Filter map[string]string
+
+func (fs Filter) validate(validFilters []string) (Filter, bool) {
+	goodFilters := make(map[string]string)
+	cnt := 0
+	len := 0
+	for f, _ := range fs {
+		len++
+		for _, v := range validFilters {
+			if f == v {
+				cnt++
+				goodFilters[f] = fs[f]
+			}
+		}
+	}
+
+	result := true
+	if len > 0 && cnt == 0 {
+		// if no valid filters are found declare filtering request as invalid
+		result = false
+	}
+
+	return goodFilters, result
+}
+
+// requires input in format: "param1::value1|param2::value2..."
+func ParseFilters(req *http.Request, header string) (filters Filter) {
+	q := req.FormValue(header)
+	q = strings.Trim(q, "\"")
+	kvp := strings.Split(q, "|")
+	filters = make(map[string]string, len(kvp))
+
+	for i, _ := range kvp {
+		kv := strings.Split(kvp[i], "::")
+		if len(kv) == 2 {
+			key := kv[0]
+			val := kv[1]
+			filters[key] = val
+		}
+	}
+
+	return filters
+}
+
+func MakeFilterString(prefix string, filters Filter, validFilters []string) (res string, ok bool) {
+	if prefix != "" {
+		prefix += "."
+	}
+	if len(filters) == 0 {
+		return "", true
+	}
+
+	filters, ok = filters.validate(validFilters)
+	if !ok {
+		return "", ok
+	}
+
+	for k, v := range filters {
+		if res != "" {
+			res += " and "
+		} else {
+			res += " where "
+		}
+		res += fmt.Sprintf("%s%s = '%s'", prefix, k, v)
+	}
+
+	return res, ok
+}
...	...	@@ -0,0 +1,76 @@
	1	+package webutility
	2	+
	3	+import (
	4	+ "fmt"
	5	+ "net/http"
	6	+ "strings"
	7	+)
	8	+
	9	+type Filter map[string]string
	10	+
	11	+func (fs Filter) validate(validFilters []string) (Filter, bool) {
	12	+ goodFilters := make(map[string]string)
	13	+ cnt := 0
	14	+ len := 0
	15	+ for f, _ := range fs {
	16	+ len++
	17	+ for _, v := range validFilters {
	18	+ if f == v {
	19	+ cnt++
	20	+ goodFilters[f] = fs[f]
	21	+ }
	22	+ }
	23	+ }
	24	+
	25	+ result := true
	26	+ if len > 0 && cnt == 0 {
	27	+ // if no valid filters are found declare filtering request as invalid
	28	+ result = false
	29	+ }
	30	+
	31	+ return goodFilters, result
	32	+}
	33	+
	34	+// requires input in format: "param1::value1\|param2::value2..."
	35	+func ParseFilters(req *http.Request, header string) (filters Filter) {
	36	+ q := req.FormValue(header)
	37	+ q = strings.Trim(q, "\"")
	38	+ kvp := strings.Split(q, "\|")
	39	+ filters = make(map[string]string, len(kvp))
	40	+
	41	+ for i, _ := range kvp {
	42	+ kv := strings.Split(kvp[i], "::")
	43	+ if len(kv) == 2 {
	44	+ key := kv[0]
	45	+ val := kv[1]
	46	+ filters[key] = val
	47	+ }
	48	+ }
	49	+
	50	+ return filters
	51	+}
	52	+
	53	+func MakeFilterString(prefix string, filters Filter, validFilters []string) (res string, ok bool) {
	54	+ if prefix != "" {
	55	+ prefix += "."
	56	+ }
	57	+ if len(filters) == 0 {
	58	+ return "", true
	59	+ }
	60	+
	61	+ filters, ok = filters.validate(validFilters)
	62	+ if !ok {
	63	+ return "", ok
	64	+ }
	65	+
	66	+ for k, v := range filters {
	67	+ if res != "" {
	68	+ res += " and "
	69	+ } else {
	70	+ res += " where "
	71	+ }
	72	+ res += fmt.Sprintf("%s%s = '%s'", prefix, k, v)
	73	+ }
	74	+
	75	+ return res, ok
	76	+}
...	...