http Request parsing, plus a convenient accessor.

R=rsc
APPROVED=rsc
DELTA=95  (40 added, 14 deleted, 41 changed)
OCL=30727
CL=30784

src/pkg/http/request.go

@@ -103,8 +103,8 @@ type Request struct {
 	// The User-Agent: header string, if sent in the request.
 	UserAgent string;
 
-	// The parsed form data. Only available after ParseForm is called.
-	FormData map[string] *vector.StringVector
+	// The parsed form. Only available after ParseForm is called.
+	Form map[string] []string;
 
 }
 
@@ -581,9 +581,9 @@ func ReadRequest(b *bufio.Reader) (req *Request, err os.Error) {
 	return req, nil
 }
 
-func parseForm(body string) (data map[string] *vector.StringVector, err os.Error) {
-	data = make(map[string] *vector.StringVector);
-	for _, kv := range strings.Split(body, "&", 0) {
+func parseForm(query string) (m map[string] []string, err os.Error) {
+	data := make(map[string] *vector.StringVector);
+	for _, kv := range strings.Split(query, "&", 0) {
 		kvPair := strings.Split(kv, "=", 2);
 
 		var key, value string;
@@ -593,7 +593,7 @@ func parseForm(body string) (data map[string] *vector.StringVector, err os.Error
 			value, e = URLUnescape(kvPair[1]);
 		}
 		if e != nil {
-			err := e;
+			err = e;
 		}
 
 		vec, ok := data[key];
@@ -603,26 +603,56 @@ func parseForm(body string) (data map[string] *vector.StringVector, err os.Error
 		}
 		vec.Push(value);
 	}
+
+	m = make(map[string] []string);
+	for k, vec := range data {
+		m[k] = vec.Data();
+	}
+
 	return
 }
 
-// ParseForm parses the request body as a form.
-// TODO(dsymonds): Parse r.Url.RawQuery instead for GET requests.
+// ParseForm parses the request body as a form for POST requests, or the raw query for GET requests.
+// It is idempotent.
 func (r *Request) ParseForm() (err os.Error) {
-	if r.Body == nil {
-		return os.ErrorString("missing form body");
-	}
-	ct, ok := r.Header["Content-Type"];
-	if !ok {
-		ct = "application/x-www-form-urlencoded";  // default
-	}
-	switch ct {
-	case "text/plain", "application/x-www-form-urlencoded":
-		buf := new(io.ByteBuffer);
-		io.Copy(r.Body, buf);
-		r.FormData, err = parseForm(string(buf.Data()));
-		return err
-	// TODO(dsymonds): Handle multipart/form-data
-	}
-	return &badStringError{"unknown Content-Type", ct};
+	if r.Form != nil {
+		return
+	}
+
+	var query string;
+
+	switch r.Method {
+	case "GET":
+		query = r.Url.RawQuery;
+	case "POST":
+		if r.Body == nil {
+			return os.ErrorString("missing form body")
+		}
+		ct, _ := r.Header["Content-Type"];
+		switch ct {
+		case "text/plain", "application/x-www-form-urlencoded", "":
+			var b []byte;
+			if b, err = io.ReadAll(r.Body); err != nil {
+				return
+			}
+			query = string(b);
+		// TODO(dsymonds): Handle multipart/form-data
+		default:
+			return &badStringError{"unknown Content-Type", ct}
+		}
+	}
+	r.Form, err = parseForm(query);
+	return
+}
+
+// FormValue returns the first value for the named component of the query.
+// FormValue calls ParseForm if necessary.
+func (r *Request) FormValue(key string) string {
+	if r.Form == nil {
+		r.ParseForm();
+	}
+	if vs, ok := r.Form[key]; ok && len(vs) > 0 {
+		return vs[0]
+	}
+	return ""
 }

src/pkg/http/request_test.go

@@ -7,56 +7,66 @@ package http
 import (
 	"fmt";
 	"http";
+	"os";
 	"testing";
 )
 
 type stringMultimap map[string] []string
 
 type parseTest struct {
-	body string;
+	query string;
 	out stringMultimap;
 }
 
 var parseTests = []parseTest{
 	parseTest{
-		body: "a=1&b=2",
+		query: "a=1&b=2",
 		out: stringMultimap{ "a": []string{ "1" }, "b": []string{ "2" } },
 	},
 	parseTest{
-		body: "a=1&a=2&a=banana",
+		query: "a=1&a=2&a=banana",
 		out: stringMultimap{ "a": []string{ "1", "2", "banana" } },
 	},
 	parseTest{
-		body: "ascii=%3Ckey%3A+0x90%3E",
+		query: "ascii=%3Ckey%3A+0x90%3E",
 		out: stringMultimap{ "ascii": []string{ "<key: 0x90>" } },
 	},
 }
 
 func TestParseForm(t *testing.T) {
 	for i, test := range parseTests {
-		data, err := parseForm(test.body);
+		form, err := parseForm(test.query);
 		if err != nil {
 			t.Errorf("test %d: Unexpected error: %v", i, err);
 			continue
 		}
-		if dlen, olen := len(data), len(test.out); dlen != olen {
-			t.Errorf("test %d: Have %d keys, want %d keys", i, dlen, olen);
+		if len(form) != len(test.out) {
+			t.Errorf("test %d: len(form) = %d, want %d", i, len(form), len(test.out));
 		}
-		for k, vs := range test.out {
-			vec, ok := data[k];
+		for k, evs := range test.out {
+			vs, ok := form[k];
 			if !ok {
 				t.Errorf("test %d: Missing key %q", i, k);
 				continue
 			}
-			if dlen, olen := vec.Len(), len(vs); dlen != olen {
-				t.Errorf("test %d: key %q: Have %d keys, want %d keys", i, k, dlen, olen);
+			if len(vs) != len(evs) {
+				t.Errorf("test %d: len(form[%q]) = %d, want %d", i, k, len(vs), len(evs));
 				continue
 			}
-			for j, v := range vs {
-				if dv := vec.At(j); dv != v {
-					t.Errorf("test %d: key %q: val %d: Have %q, want %q", i, k, j, dv, v);
+			for j, ev := range evs {
+				if v := vs[j]; v != ev {
+					t.Errorf("test %d: form[%q][%d] = %q, want %q", i, k, j, v, ev);
 				}
 			}
 		}
 	}
 }
+
+func TestQuery(t *testing.T) {
+	var err os.Error;
+	req := &Request{ Method: "GET" };
+	req.Url, err = ParseURL("http://www.google.com/search?q=foo&q=bar");
+	if q := req.FormValue("q"); q != "foo" {
+		t.Errorf(`req.FormValue("q") = %q, want "foo"`, q);
+	}
+}