mozilla
Your Search Results

    io/text-streams

    Experimental

    Provides streams for reading and writing text.

    function readTextFromFile(filename) {
      var fileIO = require("sdk/io/file");
      var text = null;
      if (fileIO.exists(filename)) {
        var TextReader = fileIO.open(filename, "r");
        if (!TextReader.closed) {
          text = TextReader.read();
          TextReader.close();
        }
      }
      return text;
    }
    function writeTextToFile(text, filename) {
      var fileIO = require("sdk/io/file");
      var TextWriter = fileIO.open(filename, "w");
      if (!TextWriter.closed) {
        TextWriter.write(text);
        TextWriter.close();
      }
    }

    Globals

    Constructors

    TextReader(inputStream, charset)

    Creates a buffered input stream that reads text from a backing stream using a given text encoding.

    You can also create TextReader objects using io/file's open() function.

    Parameters

    inputStream : stream
    The backing stream, an nsIInputStream. It must already be opened.

    charset : string
    inputStream is expected to be in the character encoding named by this value. If not specified, "UTF-8" is assumed. See nsICharsetConverterManager.idl for documentation on how to determine other valid values for this.

    TextWriter(outputStream, charset)

    Creates a buffered output stream that writes text to a backing stream using a given text encoding.

    You can also create TextWriter objects using io/file's open() function.

    Parameters

    outputStream : stream
    The backing stream, an nsIOutputStream. It must already be opened.

    charset : string
    Text will be written to outputStream using the character encoding named by this value. If not specified, "UTF-8" is assumed. See nsICharsetConverterManager.idl for documentation on how to determine other valid values for this.

    TextReader

    Methods

    close()

    Closes both the stream and its backing stream.

    read(numChars)

    Reads and returns a string from the stream. If the stream is closed, an exception is thrown.

    Parameters

    numChars : number
    The number of characters to read. If not given, the remainder of the stream is read.

    Returns

    string : The string read. If the stream is at the end, the empty string is returned.

    Properties

    closed

    True if the stream is closed.

    TextWriter

    Methods

    close()

    Flushes the backing stream's buffer and closes both the stream and the backing stream. If the stream is already closed, an exception is thrown.

    flush()

    Flushes the backing stream's buffer.

    write(str)

    Writes a string to the stream. If the stream is closed, an exception is thrown.

    Parameters

    str : string
    The string to write.

    writeAsync(str, callback)

    Writes a string on a background thread. After the write completes, the backing stream's buffer is flushed, and both the stream and the backing stream are closed, also on the background thread. If the stream is already closed, an exception is thrown immediately.

    Parameters

    str : string
    The string to write.

    callback : callback
    callback, if given, must be a function. It's called as callback(error) when the write completes. error is an Error object or undefined if there was no error. Inside callback, this is the TextWriter object.

    Properties

    closed

    True if the stream is closed.

    Document Tags and Contributors

    Contributors to this page: wbamberg, backy0175
    Last updated by: wbamberg,
    Hide Sidebar