Class FileDataSourceBuilder

A builder for configuring the file data source.

Inheritance

object

FileDataSourceBuilder

Implements

IComponentConfigurer<IDataSource>

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: LaunchDarkly.Sdk.Server.Integrations

Assembly: LaunchDarkly.ServerSdk.dll

Syntax

public sealed class FileDataSourceBuilder : IComponentConfigurer<IDataSource>

Remarks

To use the file data source, obtain a new instance of this class with DataSource(); call the builder method {@link #filePaths(String...)} to specify file path(s), and/or {@link #classpathResources(String...)} to specify classpath data resources; then pass the resulting object to DataSource(IComponentConfigurer<IDataSource>).

Constructors

FileDataSourceBuilder()

Declaration

public FileDataSourceBuilder()

Methods

AutoUpdate(bool)

Specifies whether the data source should watch for changes to the source file(s) and reload flags whenever there is a change.

Declaration

public FileDataSourceBuilder AutoUpdate(bool autoUpdate)

Parameters

Type	Name	Description
bool	autoUpdate	true if flags should be reloaded whenever a source file changes

Returns

Type	Description
FileDataSourceBuilder	the same factory object

Remarks

This option is off by default: unless you set this option to true, files will only be loaded once.

Whenever possible, you should update a file's entire contents in one atomic operation; in Unix-like OSes, that can be done by creating a temporary file, writing to it, and then renaming it to replace the original file. In Windows, that is not always possible, so FileDataSource might detect an update before the file has been fully written; in that case it will retry until it succeeds.

Note that auto-updating may not work if any of the files you specified has an invalid directory path.

Build(LdClientContext)

Called internally by the SDK to create an implementation instance. Applications should not need to call this method.

Declaration

public IDataSource Build(LdClientContext context)

Parameters

Type	Name	Description
LdClientContext	context	provides configuration properties and other components from the current SDK client instance

Returns

Type	Description
IDataSource	a instance of the component type

DuplicateKeysHandling(DuplicateKeysHandling)

Specifies how to handle keys that are duplicated across files.

Declaration

public FileDataSourceBuilder DuplicateKeysHandling(FileDataTypes.DuplicateKeysHandling duplicateKeysHandling)

Parameters

Type	Name	Description
FileDataTypes.DuplicateKeysHandling	duplicateKeysHandling	how duplicate keys should be handled

Returns

Type	Description
FileDataSourceBuilder	the same factory object

Remarks

By default, the file data source will throw if keys are duplicated across files.

FilePaths(params string[])

Adds any number of source files for loading flag data, specifying each file path as a string.

Declaration

public FileDataSourceBuilder FilePaths(params string[] paths)

Parameters

Type	Name	Description
string[]	paths	path(s) to the source file(s); may be absolute or relative to the current working directory

Returns

Type	Description
FileDataSourceBuilder	the same factory object

Remarks

The files will not actually be loaded until the LaunchDarkly client starts up.

Files are normally expected to contain JSON; see Parser(Func<string, object>) for alternatives.

FileReader(IFileReader)

Specifies an alternate file reader which can support custom OS error handling and retry logic.

Declaration

public FileDataSourceBuilder FileReader(FileDataTypes.IFileReader fileReader)

Parameters

Type	Name	Description
FileDataTypes.IFileReader	fileReader	The flag file reader.

Returns

Type	Description
FileDataSourceBuilder	the same factory object

Parser(Func<string, object>)

Specifies an alternate parsing function to use for non-JSON source files.

Declaration

public FileDataSourceBuilder Parser(Func<string, object> parseFn)

Parameters

Type	Name	Description
Func<string, object>	parseFn	the parsing function

Returns

Type	Description
FileDataSourceBuilder	the same factory object

Remarks

By default, the file data source attempts to parse files as JSON objects. You may wish to use another format, such as YAML. To avoid bringing in additional dependencies that might conflict with application dependencies, the LaunchDarkly SDK does not import a YAML parser, but you can use Parser to specify a parser of your choice.

The function you provide should take a string and return an object which should contain only the basic types that can be represented in JSON: so, for instance, string values should be string, arrays should be List, and objects with key-value pairs should be Dictionary<string, object>. It should throw an exception if it can't parse the data.

The file data source will still try to parse files as JSON if their first non-whitespace character is '{', but if that fails, it will use the custom parser.

Here is an example of how you would do this with the YamlDotNet package. Note the use of a DeserializerBuilder configuration method to tell the parser that it should interpret a property like on: true or variation: 3 as a boolean or integer rather than a string; YAML syntax is very flexible, so how you configure the parser will depend on how you are formatting the file, but data types do matter in flag configurations so you do not want it to simply read every property as a string.

var yaml = new DeserializerBuilder()
    .WithAttemptingUnquotedStringTypeDeserialization()
    .Build();
var source = FileData.DataSource()
    .FilePaths(myYamlFilePath)
    .Parser(s => yaml.Deserialize<object>(s));

SkipMissingPaths(bool)

Specifies to ignore missing file paths instead of treating them as an error.

Declaration

public FileDataSourceBuilder SkipMissingPaths(bool skipMissingPaths)

Parameters

Type	Name	Description
bool	skipMissingPaths	If true, missing file paths will be skipped, otherwise they will be treated as an error

Returns

Type	Description
FileDataSourceBuilder	the same factory object

Implements

IComponentConfigurer<T>

See Also

FileData