The LXDatedFileEndpoint writes Log Entries to a selected file, which changes a daily. Developers can specify a base URL for the log files, and the Endpoint will prepend the current datestamp to each file’s name. At each midnight UTC, the Endpoint will create a new dated file for that day’s logging.

The Dated File Endpoint is safe to be used in environments featuring concurrency. This Endpoint does some of its work asynchronously to allow better logging performance. Because the Dated File Endpoint takes advantage of asynchronous technologies, Log Entries written to this Endpoint may not appear until slightly after execution has moved on. In other words, if your application attempts to create a Log Entry directly before it crashes, it may not be delivered before the crash occurs. While debugging your application, if the asynchronous nature of this Endpoint is problematic, consider using a synchronous Console Endpoint in addition.

Usage

Initializers

The following initializers are available for LXDatedFileEndpoint:

init?(baseURL: minimumPriorityLevel: dateFormatter: entryFormatter: )

Parameters

baseURL Type: NSURL?
Default: see below		 The URL used to build the date files’ URLs; see description below
minimumPriorityLevel Type: LXPriorityLevel
Default: .All		 The minimum Priority Level a Log Entry must meet to be accepted by this Endpoint
dateFormatter Type: LXDateFormatter
Default: .standardFormatter()		 The formatter used by this Endpoint to serialize a Log Entry’s dateTime property to a string
entryFormatter Type: LXEntryFormatter
Default: .standardFormatter()		 The formatter used by this Endpoint to serialize each Log Entry to a string

This Endpoint writes Log Entries to a series of files specified by baseURL, with each file’s name automatically prepended with a UTC datestamp in the format yyyy-MM-dd. If the specified file cannot be opened, or if the datestamp-prepended URL evaluates to nil, the initializer may fail.

If omitted, the URL defaults to {AppSupport}/{bundleID}/logs/{datestamp}_log.txt, where {AppSupport} is the system-determined Application Support directory, {bundleID} is the host application’s bundleIdentifier string, and {datestamp} is the current UTC date’s datestamp.

As an example, if an LXDatedFileEndpoint is initialized with its default parameter values and today’s date is October 5, 2015, it will create a file in Application Support/{bundleID}/logs/ named 2015-10-05_log.txt. At midnight UTC, Log Entries will automatically begin being written to a new file named 2015-10-06_log.txt.

Returns an initialized Dated File Endpoint instance if successful, or nil if the file cannot be opened.

Notifications

LXDatedFileEndpoint instances will post notifications before and after they automatically move to a new dated log file.

Before changing files, the instance will post a LXFileEndpointWillRotateFilesNotification notification. The notification’s object is the actual Endpoint instance that is changing files. The userInfo dictionary contains the current and next URLs, at the LXFileEndpointRotationCurrentURLKey and LXFileEndpointRotationNextURLKey keys, respectively.

After changing files, the instance will post a LXFileEndpointDidRotateFilesNotification notification. The notification’s object is the actual Endpoint instance that is changing files. The userInfo dictionary contains the current and previous URLs, at the LXFileEndpointRotationCurrentURLKey and LXFileEndpointRotationPreviousURLKey keys, respectively.

All notifications are posted to the default notification center.

Note: Developers should not modify the log file currently in use by the Endpoint.