wide/playground/autocomplete.go

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2017-03-14 17:40:45 +03:00
// Copyright (c) 2014-2017, b3log.org & hacpai.com
2015-02-15 09:24:49 +03:00
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package playground
import (
"bytes"
"encoding/json"
"net/http"
"os/exec"
"strconv"
"strings"
"github.com/b3log/wide/session"
"github.com/b3log/wide/util"
)
// AutocompleteHandler handles request of code autocompletion.
func AutocompleteHandler(w http.ResponseWriter, r *http.Request) {
var args map[string]interface{}
if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
logger.Error(err)
http.Error(w, err.Error(), 500)
return
}
session, _ := session.HTTPSession.Get(r, "wide-session")
if session.IsNew {
http.Error(w, "Forbidden", http.StatusForbidden)
return
}
code := args["code"].(string)
line := int(args["cursorLine"].(float64))
ch := int(args["cursorCh"].(float64))
offset := getCursorOffset(code, line, ch)
argv := []string{"-f=json", "autocomplete", strconv.Itoa(offset)}
gocode := util.Go.GetExecutableInGOBIN("gocode")
cmd := exec.Command(gocode, argv...)
stdin, _ := cmd.StdinPipe()
stdin.Write([]byte(code))
stdin.Close()
output, err := cmd.CombinedOutput()
if nil != err {
logger.Error(err)
http.Error(w, err.Error(), 500)
return
}
w.Header().Set("Content-Type", "application/json")
w.Write(output)
}
// getCursorOffset calculates the cursor offset.
//
// line is the line number, starts with 0 that means the first line
// ch is the column number, starts with 0 that means the first column
func getCursorOffset(code string, line, ch int) (offset int) {
lines := strings.Split(code, "\n")
// calculate sum length of lines before
for i := 0; i < line; i++ {
offset += len(lines[i])
}
// calculate length of the current line and column
curLine := lines[line]
var buffer bytes.Buffer
r := []rune(curLine)
for i := 0; i < ch; i++ {
buffer.WriteString(string(r[i]))
}
offset += len(buffer.String()) // append length of current line
offset += line // append number of '\n'
return offset
}