Class FileAppender

The file appender appends log messages to a file.

Version

1

Hierarchy (view full)

Constructors

constructor

Properties

_active _appending _backingUp _buffer _currentFileName _currentTargetPath _failed _file _fileNamePatternContainsInstancePlaceholder _fileWriteBuffer _filterRelation _filters _instanceId _instanceStartTime _nextDateRollover _size _writable acceptExistingFile ageLookup backupCompression dateRollover dayOfTheWeekLookup deferredStart fileExtension fileNamePattern format maxFileSize monthLookup noonLookup pretty separatorLookup severityLookup syntax targetPath timeFormat

Accessors

buffer filterRelation filters

Methods

_appendMessage _backupFile _compressBackupFile _flush _fs_createReadStream _fs_createWriteStream _fs_mkdir _fs_open _fs_readdir _fs_rename _fs_rm _fs_stat _handleError _handleMessage _handleOpen activate addFilter cleanAnsiStyle clearBuffer close evalFilters getDirEntry getFile getFileName getFormatLookup getGzipFileExtension getTargetPath isWritable openFile pause processFilePattern processFormat processMessageParameters processTimeFormat pushToBuffer receiveFallBackMessage receiveMessage resume setNextDateRollover setTargetPath

Constructors

constructor

  • new FileAppender(format?, timeFormat?, formatLookups?, fileAppenderOptions?): FileAppender

  • Parameters

    • format: string = DefaultFormats.MESSAGE

      The log message format to use. All properties of a log message can be inserted to their placeholders, e.g. '%id%'.

    • timeFormat: string = DefaultFormats.TIME

      The time format to use for the %time% placeholder. The time format is inspired by https://msdn.microsoft.com/de-de/library/8kb3ddd4(v=vs.110).aspx, but some of the placeholders might not work.

    • Optional formatLookups: FormatLookup

      map containing lookups for the printing of formatted messages, see DefaultFormats

    • fileAppenderOptions: FileAppenderOptions = {}

      map containing the options specifically for the file appender. fileNamePattern defaults to ''; fileExtension defaults to '.log'; targetPath defaults to the current working directory; acceptExistingFile defaults to false; maxFileSize defaults to 1000000000; backupCompression defaults to BackupCompressionMode.GZIP; syntax defaults to FileAppenderSyntax.PLAIN; pretty defaults to false; dateRollover defaults to false; deferredStart defaults to false;

    Returns FileAppender

Properties

Protected _active

_active: boolean = false

The flag indicating the activation state.

Protected _appending

_appending: boolean = false

Flag indicating that the log file currently is written.

Protected _backingUp

_backingUp: boolean = false

Flag indicating that the log file currently is backed up.

Protected _buffer

_buffer: LogMessage[]

A buffer that will be filled with log messages until the Appender is writable.

Protected _currentFileName

_currentFileName: string = ""

Stores the currently used file name of the log file. This will be recalculated in case of date rollovers.

Protected _currentTargetPath

_currentTargetPath: string = ""

Stores the currently used target path.

Protected _failed

_failed: boolean = false

Flag indicating, that writing to the log file failed.

Protected _file

_file: null | FileHandle = null

The file handle opened for appending the log entries.

Protected _fileNamePatternContainsInstancePlaceholder

_fileNamePatternContainsInstancePlaceholder: boolean = false

Flag indicating whether the file name pattern already contains a placeholder for the instance counter.

Protected _fileWriteBuffer

_fileWriteBuffer: null | Buffer = null

Used internally for buffering contents to be written to the file.

_filterRelation

_filterRelation: FilterRelation

The relation, to which all the appenders results must adhere. See FilterRelation.

Protected _filters

_filters: Filter[]

The filter that will be evaluated in order to determine whether a message shall be handled by this appender.

Protected _instanceId

_instanceId: number = 0

The, by existing log files, determined instance id that will be issued if a placeholder is present in the file name pattern, or if existing files shall not be overridden, or if the log file is not writable. The value will be preserved in case of date or file size rollovers.

Protected _instanceStartTime

_instanceStartTime: Date = ...

Timestamp when starting the current process.

Protected _nextDateRollover

_nextDateRollover: null | Date = null

The point in time when the file name shall be re-evaluated and a date rollover is to be performed Currently, this property is set but ignored.

Protected _size

_size: number = 0

The current file size

Protected _writable

_writable: boolean = false

The writable flag of the appender.

Protected acceptExistingFile

acceptExistingFile: boolean = false

Sets the Appender to append logs to an existing log file on startup if it already exists. See FileAppenderOptions#acceptExistingFile.

Protected ageLookup

ageLookup: string[] = DefaultFormats.ENUMS.AGE

see DefaultFormats.ENUMS.AGE

Protected backupCompression

backupCompression: BackupCompressionMode = BackupCompressionMode.GZIP

The backup compression mode. See FileAppenderOptions#backupCompression.

Protected dateRollover

dateRollover: boolean = false

Whether to re-determine the file name at 00:00h when the date changes. See FileAppenderOptions#dateRollover. Currently, this feature is not supported.

Protected dayOfTheWeekLookup

dayOfTheWeekLookup: string[] = DefaultFormats.ENUMS.DAY_OF_WEEK

see DefaultFormats.ENUMS.DAY_OF_WEEK

Protected deferredStart

deferredStart: boolean = false

Whether the appender shall immediately create its file handle on instanciation. If set to true, clients habe to activate it explicitly.

Protected fileExtension

fileExtension: string = ".log"

The file extension that is being appended to the file name, should start with period (.). See FileAppenderOptions#fileExtension.

Protected fileNamePattern

fileNamePattern: string = "yyyy-MM-dd_HH-mm_%INSTANCE%"

The name pattern of the log file. See FileAppenderOptions#fileNamePattern.

Protected format

format: string

The log message format to use. All properties of a log message can be inserted to their placeholders, e.g. '%id%'.

Protected maxFileSize

maxFileSize: number = ...

The maximum log file size. If exceeded, a backup will be created. Defaults to 1GB See FileAppenderOptions#maxFileSize.

Protected monthLookup

monthLookup: string[] = DefaultFormats.ENUMS.MONTH

see DefaultFormats.ENUMS.MONTH

Protected noonLookup

noonLookup: string[] = DefaultFormats.ENUMS.NOON

see DefaultFormats.ENUMS.NOON

Protected pretty

pretty: boolean = false

Whether to print pretty XML and JSON. See FileAppenderOptions#pretty.

Protected separatorLookup

separatorLookup: string[] = DefaultFormats.ENUMS.SEPARATOR

see DefaultFormats.ENUMS.SEPARATOR

Protected severityLookup

severityLookup: string[] = DefaultFormats.ENUMS.SEVERITY

A simple lookup from where the strings for the severity levels can be fetched. see DefaultFormats.ENUMS.SEVERITY

Protected syntax

syntax: FileAppenderSyntax = FileAppenderSyntax.PLAIN

The write syntax mode. See FileAppenderOptions#syntax.

Protected targetPath

targetPath: string = ...

The path to generate the log files to. See FileAppenderOptions#targetPath.

Protected timeFormat

timeFormat: string

The time format to use for the %time% placeholder. The time format is inspired by https://msdn.microsoft.com/de-de/library/8kb3ddd4(v=vs.110).aspx, but some of the placeholders might not work.

Accessors

buffer

filterRelation

filters

Methods

_appendMessage

Protected _backupFile

  • _backupFile(): Promise<void>

  • Backs the log file up using the specified compression method.

    Returns Promise<void>

Protected _compressBackupFile

  • _compressBackupFile(fileName): Promise<void>

  • creates a compressed file from a given file fith the file extension '.gz' appended to the file name.

    Parameters

    • fileName: string

    Returns Promise<void>

Protected _flush

  • _flush(): void

  • Appends the current content to the file. Checks the resulting file size and backs the file up, if needed. Repeats the flush, if new content to be logged has arrived in the mean time.

    Returns void

Protected _fs_createReadStream

Protected _fs_createWriteStream

Protected _fs_mkdir

  • _fs_mkdir(path, options?): Promise<undefined | string>

  • Parameters

    • path: string
    • Optional options: MakeDirectoryOptions

    Returns Promise<undefined | string>

Protected _fs_open

Protected _fs_readdir

  • _fs_readdir(path, options?): Promise<string[]>

  • Parameters

    • path: string
    • Optional options: ObjectEncodingOptions & {
          withFileTypes?: boolean;
      }

    Returns Promise<string[]>

Protected _fs_rename

  • _fs_rename(srcPath, targetPath): Promise<void>

  • Parameters

    • srcPath: string
    • targetPath: string

    Returns Promise<void>

Protected _fs_rm

Protected _fs_stat

Protected _handleError

Protected _handleMessage

Protected _handleOpen

activate

addFilter

cleanAnsiStyle

clearBuffer

close

Protected evalFilters

Protected getDirEntry

  • getDirEntry(fileName, entries): null | Dirent

  • Returns a dirent entry matching the specified file name from a collection of dirent entries

    Parameters

    • fileName: string
    • entries: Dirent[]

    Returns null | Dirent

Protected getFile

getFileName

  • getFileName(): string

  • Returns string

    the file name according to the file name pattern specified including the instance id, if required.

Protected getFormatLookup

Protected getGzipFileExtension

getTargetPath

isWritable

Protected openFile

  • openFile(): Promise<void>

  • Initializes the appender by either cleaning the file or reading its current size.

    Returns Promise<void>

Protected pause

processFilePattern

processFormat

processMessageParameters

processTimeFormat

Protected pushToBuffer

receiveFallBackMessage

receiveMessage

  • receiveMessage(msg): boolean

  • The input function of an Appender for any log message. This function calls the filter evaluation, and hands the message over to the _handleMessage method, if the appender is currently writable. If the appender is not writable, the message is stored to the internal buffer.

    Parameters

    • msg: LogMessage

      The message that shall be received and appended.

    Returns boolean

    True, if the message was handled, false otherwise.

Protected resume

Protected setNextDateRollover

setTargetPath

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constructor_active_appending_backingUp_buffer_currentFileName_currentTargetPath_failed_file_fileNamePatternContainsInstancePlaceholder_fileWriteBuffer_filterRelation_filters_instanceId_instanceStartTime_nextDateRollover_size_writableacceptExistingFileageLookupbackupCompressiondateRolloverdayOfTheWeekLookupdeferredStartfileExtensionfileNamePatternformatmaxFileSizemonthLookupnoonLookupprettyseparatorLookupseverityLookupsyntaxtargetPathtimeFormatbufferfilterRelationfilters_appendMessage_backupFile_compressBackupFile_flush_fs_createReadStream_fs_createWriteStream_fs_mkdir_fs_open_fs_readdir_fs_rename_fs_rm_fs_stat_handleError_handleMessage_handleOpenactivateaddFiltercleanAnsiStyleclearBuffercloseevalFiltersgetDirEntrygetFilegetFileNamegetFormatLookupgetGzipFileExtensiongetTargetPathisWritableopenFilepauseprocessFilePatternprocessFormatprocessMessageParametersprocessTimeFormatpushToBufferreceiveFallBackMessagereceiveMessageresumesetNextDateRolloversetTargetPath