path: root/internal/jsre/completion.go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package jsre

import (
    "sort"
    "strings"

    "github.com/robertkrimen/otto"
)

// CompleteKeywords returns potential continuations for the given line. Since line is
// evaluated, callers need to make sure that evaluating line does not have side effects.
func (jsre *JSRE) CompleteKeywords(line string) []string {
    var results []string
    jsre.Do(func(vm *otto.Otto) {
        results = getCompletions(vm, line)
    })
    return results
}

func getCompletions(vm *otto.Otto, line string) (results []string) {
    parts := strings.Split(line, ".")
    objRef := "this"
    prefix := line
    if len(parts) > 1 {
        objRef = strings.Join(parts[0:len(parts)-1], ".")
        prefix = parts[len(parts)-1]
    }

    obj, _ := vm.Object(objRef)
    if obj == nil {
        return nil
    }
    iterOwnAndConstructorKeys(vm, obj, func(k string) {
        if strings.HasPrefix(k, prefix) {
            if objRef == "this" {
                results = append(results, k)
            } else {
                results = append(results, strings.Join(parts[:len(parts)-1], ".")+"."+k)
            }
        }
    })

    // Append opening parenthesis (for functions) or dot (for objects)
    // if the line itself is the only completion.
    if len(results) == 1 && results[0] == line {
        obj, _ := vm.Object(line)
        if obj != nil {
            if obj.Class() == "Function" {
                results[0] += "("
            } else {
                results[0] += "."
            }
        }
    }

    sort.Strings(results)
    return results
}