Overview
The Fluent API for runtime type parsers in PocketCsvReader provides an intuitive and flexible way to define parsers for various runtime types. This is particularly useful when working with custom or non-standard types serialized in a CSV file that need to be correctly deserialized.
By defining a set of parsers, you ensure that these types are always deserialized properly across different CSV files. However, if the deserialization logic varies depending on the field, you should register the parser at the field level instead. See: Providing a Custom Parser.
Defining a set of parsers
You can configure runtime type parsers in two ways:
- Using a CSV Profile
The CsvProfile class allows you to define a set of parsers as part of the CSV processing configuration:
var profile = new CsvProfile(
new DialectDescriptorBuilder().Build()
, new SchemaDescriptorBuilder()
.Indexed()
.WithField<YearMonth>()
.Build()
, null
, new RuntimeParsersDescriptorBuilder()
.WithParser(...)
.Build()
);
- Using a CSV Reader Builder
You can also configure parsers using the CsvReaderBuilder class:
var builder = new CsvReaderBuilder().WithParsers
(
new RuntimeParsersDescriptorBuilder()
.WithParser(...)
);
var reader = builder.Build();
Registering a Custom Parser
To define custom parsers, instantiate a RuntimeParsersDescriptorBuilder and use its method WithParser method.
Example: Custom Parser for Point
Point parse(string input)
{
var parts = input.Split(';');
return new Point(parts[0], parts[1]);
}
var schema = new RuntimeParsersDescriptorBuilder()
.WithParser<Point>(parse)
.Build();
In this example:
- The custom parser splits the input string using ; as a delimiter.
- It parses the extracted values into integers.
- It creates a Point instance from the parsed values.
Handling Multiple Parsers
- You can define multiple parsers for different types.
- If two parsers are registered for the same type, the most recently registered parser overrides the previous one.
