cwebp/lib/wrapper.js

node.js wrapper for cwebp and dwebp binaries from WebP image processing utility

// Generated by CoffeeScript 1.9.1
var When, Wrapper, mixin, spawn;

When = require('when');

spawn = require('child_process').spawn;

mixin = require('./utils').mixin;

module.exports = Wrapper = (function() {
  mixin(Wrapper, require('./args'));

  mixin(Wrapper, require('./io'));

  function Wrapper(source, bin) {
    this._args = {
      _: []
    };
    this.source = source;
    this.bin = bin || this.constructor.bin;
  }

  Wrapper.prototype._spawn = function(args, stdin, stdout) {
    var onClose, onErr, proc, promise, ref, reject, res, resolve, stderr, stdio;
    if (stdin == null) {
      stdin = false;
    }
    if (stdout == null) {
      stdout = false;
    }
    ref = When.defer(), resolve = ref.resolve, reject = ref.reject, promise = ref.promise;
    stderr = '';
    stdio = [stdin ? 'pipe' : 'ignore', stdout ? 'pipe' : 'ignore', 'pipe'];
    proc = spawn(this.bin, args, {
      stdio: stdio
    });
    proc.once('error', reject);
    proc.once('close', onClose = function(code, signal) {
      var err;
      if (code !== 0 || signal !== null) {
        err = new Error("Command failed: " + stderr);
        err.code = code;
        err.signal = signal;
        return reject(err);
      } else {
        return resolve();
      }
    });
    proc.stderr.on('data', onErr = function(data) {
      return stderr += data;
    });
    promise = promise.ensure(function() {
      proc.removeListener('error', reject);
      proc.removeListener('close', onClose);
      return proc.stderr.removeListener('close', onErr);
    });
    res = {
      promise: promise
    };
    if (stdin) {
      res.stdin = proc.stdin;
    }
    if (stdout) {
      res.stdout = proc.stdout;
    }
    return res;
  };

  return Wrapper;

})();