nsextensionmanager.js

从国外的站点上淘的个人财务管理系统．开源．

 * Construct a nsIUpdateItem with the supplied metadata
 * ...
 */
function makeItem(id, version, locationKey, minVersion, maxVersion, name, 
                  updateURL, updateHash, iconURL, updateRDF, type) {
  var item = Components.classes["@mozilla.org/updates/item;1"]
                       .createInstance(Components.interfaces.nsIUpdateItem);
  item.init(id, version, locationKey, minVersion, maxVersion, name,
            updateURL, updateHash, iconURL, updateRDF, type);
  return item;
}

/**
 * Gets the specified directory at the speciifed hierarchy under a 
 * Directory Service key. 
 * @param   key
 *          The Directory Service Key to start from
 * @param   pathArray
 *          An array of path components to locate beneath the directory 
 *          specified by |key|
 * @return  nsIFile object for the location specified. If the directory
 *          requested does not exist, it is created, along with any
 *          parent directories that need to be created.
 */
function getDir(key, pathArray) {
  return getDirInternal(key, pathArray, true);
}

/**
 * Gets the specified directory at the speciifed hierarchy under a 
 * Directory Service key. 
 * @param   key
 *          The Directory Service Key to start from
 * @param   pathArray
 *          An array of path components to locate beneath the directory 
 *          specified by |key|
 * @return  nsIFile object for the location specified. If the directory
 *          requested does not exist, it is NOT created.
 */
function getDirNoCreate(key, pathArray) {
  return getDirInternal(key, pathArray, false);
}

/**
 * Gets the specified directory at the speciifed hierarchy under a 
 * Directory Service key. 
 * @param   key
 *          The Directory Service Key to start from
 * @param   pathArray
 *          An array of path components to locate beneath the directory 
 *          specified by |key|
 * @param   shouldCreate
 *          true if the directory hierarchy specified in |pathArray|
 *          should be created if it does not exist,
 *          false otherwise.
 * @return  nsIFile object for the location specified. 
 */
function getDirInternal(key, pathArray, shouldCreate) {
  var fileLocator = Components.classes["@mozilla.org/file/directory_service;1"]
                              .getService(Components.interfaces.nsIProperties);
  var dir = fileLocator.get(key, nsILocalFile);
  for (var i = 0; i < pathArray.length; ++i) {
    dir.append(pathArray[i]);
    if (shouldCreate && !dir.exists())
      dir.create(nsILocalFile.DIRECTORY_TYPE, PERMS_DIRECTORY);
  }
  dir.followLinks = false;
  return dir;
}

/**
 * Gets the file at the speciifed hierarchy under a Directory Service key.
 * @param   key
 *          The Directory Service Key to start from
 * @param   pathArray
 *          An array of path components to locate beneath the directory 
 *          specified by |key|. The last item in this array must be the
 *          leaf name of a file.
 * @return  nsIFile object for the file specified. The file is NOT created
 *          if it does not exist, however all required directories along 
 *          the way are.
 */
function getFile(key, pathArray) {
  var file = getDir(key, pathArray.slice(0, -1));
  file.append(pathArray[pathArray.length - 1]);
  return file;
}

/**
 * Gets the descriptor of a directory as a relative path to common base
 * directories (profile, user home, app install dir, etc).
 *
 * @param   itemLocation
 *          The nsILocalFile representing the item's directory.
 * @param   installLocation the nsIInstallLocation for this item
 */
function getDescriptorFromFile(itemLocation, installLocation) {
  var baseDir = installLocation.location;

  if (baseDir && baseDir.contains(itemLocation, true)) {
    return "rel%" + itemLocation.getRelativeDescriptor(baseDir);
  }

  return "abs%" + itemLocation.persistentDescriptor;
}

function getAbsoluteDescriptor(itemLocation) {
  return itemLocation.persistentDescriptor;
}

/**
 * Initializes a Local File object based on a descriptor
 * provided by "getDescriptorFromFile".
 *
 * @param   descriptor
 *          The descriptor that locates the directory
 * @param   installLocation
 *          The nsIInstallLocation object for this item.
 * @returns The nsILocalFile object representing the location of the item
 */
function getFileFromDescriptor(descriptor, installLocation) {
  var location = Components.classes["@mozilla.org/file/local;1"]
                           .createInstance(nsILocalFile);

  var m = descriptor.match(/^(abs|rel)\%(.*)$/);
  if (!m)
    throw Components.results.NS_ERROR_INVALID_ARG;

  if (m[1] == "rel") {
    location.setRelativeDescriptor(installLocation.location, m[2]);
  }
  else {
    location.persistentDescriptor = m[2];
  }

  return location;
}

/**
 * Determines if a file is an item package - either a XPI or a JAR file.
 * @param   file
 *          The file to check
 * @returns true if the file is an item package, false otherwise.
 */
function fileIsItemPackage(file) {
  var fileURL = getURIFromFile(file);
  if (fileURL instanceof nsIURL)
    var extension = fileURL.fileExtension.toLowerCase();
  return extension == "xpi" || extension == "jar";
}

/** 
 * Return the leaf name used by the extension system for staging an item.
 * @param   id
 *          The GUID of the item
 * @param   type
 *          The nsIUpdateItem type of the item
 * @returns The leaf name of the staged file.
 */
function getStagedLeafName(id, type) {
  if (type == nsIUpdateItem.TYPE_THEME) 
    return id + ".jar";
  return id + ".xpi";
}

/**
 * Opens a safe file output stream for writing. 
 * @param   file
 *          The file to write to.
 * @param   modeFlags
 *          (optional) File open flags. Can be undefined. 
 * @returns nsIFileOutputStream to write to.
 */
function openSafeFileOutputStream(file, modeFlags) {
  var fos = Components.classes["@mozilla.org/network/safe-file-output-stream;1"]
                      .createInstance(Components.interfaces.nsIFileOutputStream);
  if (modeFlags === undefined)
    modeFlags = MODE_WRONLY | MODE_CREATE | MODE_TRUNCATE;
  if (!file.exists()) 
    file.create(nsILocalFile.NORMAL_FILE_TYPE, PERMS_FILE);
  fos.init(file, modeFlags, PERMS_FILE, 0);
  return fos;
}

/**
 * Closes a safe file output stream.
 * @param   stream
 *          The stream to close.
 */
function closeSafeFileOutputStream(stream) {
  if (stream instanceof Components.interfaces.nsISafeOutputStream)
    stream.finish();
  else
    stream.close();
}

/**
 * Deletes a directory and its children. First it tries nsIFile::Remove(true).
 * If that fails it will fall back to recursing, setting the appropriate
 * permissions, and deleting the current entry. This is needed for when we have
 * rights to delete a directory but there are entries that have a read-only
 * attribute (e.g. a copy restore from a read-only CD, etc.)
 * @param   dir
 *          A nsIFile for the directory to be deleted
 */
function removeDirRecursive(dir) {
  try {
    dir.remove(true);
    return;
  }
  catch (e) {
  }

  var dirEntries = dir.directoryEntries;
  while (dirEntries.hasMoreElements()) {
    var entry = dirEntries.getNext().QueryInterface(Components.interfaces.nsIFile);

    if (entry.isDirectory()) {
      removeDirRecursive(entry);
    }
    else {
      entry.permissions = PERMS_FILE;
      entry.remove(false);
    }
  }
  dir.permissions = PERMS_DIRECTORY;
  dir.remove(true);
}

/**
 * Logs a string to the error console. 
 * @param   string
 *          The string to write to the error console..
 */  
function LOG(string) {
  if (gLoggingEnabled) {
    dump("*** " + string + "\n");
    gConsole.logStringMessage(string);
  }
}

/** 
 * Randomize the specified file name. Used to force RDF to bypass the cache
 * when loading certain types of files.
 * @param   fileName 
 *          A file name to randomize, e.g. install.rdf
 * @returns A randomized file name, e.g. install-xyz.rdf
 */
function getRandomFileName(fileName) {
  var extensionDelimiter = fileName.lastIndexOf(".");
  var prefix = fileName.substr(0, extensionDelimiter);
  var suffix = fileName.substr(extensionDelimiter);
  
  var characters = "abcdefghijklmnopqrstuvwxyz0123456789";
  var nameString = prefix + "-";
  for (var i = 0; i < 3; ++i) {
    var index = Math.round((Math.random()) * characters.length);
    nameString += characters.charAt(index);
  }
  return nameString + "." + suffix;
}

/**
 * Get the RDF URI prefix of a nsIUpdateItem type. This function should be used
 * ONLY to support Firefox 1.0 Update RDF files! Item URIs in the datasource 
 * are NOT prefixed.
 * @param   type
 *          The nsIUpdateItem type to find a RDF URI prefix for
 * @returns The RDF URI prefix.
 */
function getItemPrefix(type) {
  if (type & nsIUpdateItem.TYPE_EXTENSION) 
    return PREFIX_EXTENSION;
  else if (type & nsIUpdateItem.TYPE_THEME)
    return PREFIX_THEME;
  return PREFIX_ITEM_URI;
}

/**
 * Trims a prefix from a string.
 * @param   string
 *          The source string
 * @param   prefix
 *          The prefix to remove.
 * @returns The suffix (string - prefix)
 */
function stripPrefix(string, prefix) {
  return string.substr(prefix.length);
}

/**
 * Gets a File URL spec for a nsIFile
 * @param   file
 *          The file to get a file URL spec to
 * @returns The file URL spec to the file
 */
function getURLSpecFromFile(file) {
  var ioServ = Components.classes["@mozilla.org/network/io-service;1"]
                         .getService(Components.interfaces.nsIIOService);
  var fph = ioServ.getProtocolHandler("file")
                  .QueryInterface(Components.interfaces.nsIFileProtocolHandler);
  return fph.getURLSpecFromFile(file);
}

/**
 * Constructs a URI to a spec.
 * @param   spec
 *          The spec to construct a URI to
 * @returns The nsIURI constructed.
 */
function newURI(spec) {
  var ioServ = Components.classes["@mozilla.org/network/io-service;1"]
                         .getService(Components.interfaces.nsIIOService);
  return ioServ.newURI(spec, null, null);
}

/** 
 * Constructs a File URI to a nsIFile
 * @param   file
 *          The file to construct a File URI to
 * @returns The file URI to the file
 */
function getURIFromFile(file) {
  var ioServ = Components.classes["@mozilla.org/network/io-service;1"]
                         .getService(Components.interfaces.nsIIOService);
  return ioServ.newFileURI(file);
}

/**
 * @returns Whether or not we are currently running in safe mode.
 */
function inSafeMode() {
  return gApp.inSafeMode;
}

/**
 * Extract the string value from a RDF Literal or Resource
 * @param   literalOrResource
 *          RDF String Literal or Resource
 * @returns String value of the literal or resource, or undefined if the object
 *          supplied is not a RDF string literal or resource.
 */
function stringData(literalOrResource) {
  if (literalOrResource instanceof Components.interfaces.nsIRDFLiteral)
    return literalOrResource.Value;
  if (literalOrResource instanceof Components.interfaces.nsIRDFResource)
    return literalOrResource.Value;
  return undefined;
}

/**
 * Extract the integer value of a RDF Literal
 * @param   literal
 *          nsIRDFInt literal
 * @return  integer value of the literal
 */
function intData(literal) {
  if (literal instanceof Components.interfaces.nsIRDFInt)
    return literal.Value;
  return undefined;
}

/**
 * Gets a property from an install manifest.
 * @param   installManifest
 *          An Install Manifest datasource to read from
 * @param   property
 *          The name of a proprety to read (sans EM_NS)
 * @returns The literal value of the property, or undefined if the property has
 *          no value.
 */
function getManifestProperty(installManifest, property) {
  var target = installManifest.GetTarget(gInstallManifestRoot, 
                                         gRDF.GetResource(EM_NS(property)), true);
  var val = stringData(target);
  return val === undefined ? intData(target) : val;
}