jimnoble/object-string-map

Use a text map to turn objects into strings and back again.

String Map

Use a text map to turn simple objects into strings and back again.

Good for moving structured data into and out of file paths and URLs.

Usage

Create a class for your data. A flat POCO with simple types such as int, string, Guid and DateTime:

public class FileKey
{
    int AccountId { get; set; }
    
    DateTime? CreateTime { get; set; }
}

Create a new StringMap that describes how to turn your data to and from a string:

var map = new StringMap<FileKey>(
    "/accounts/{AccountId}/{CreateTime:yyyy/MM/dd}/data.json");

Use the StringMap to turn an object into a string:

var obj = new FileKey
{
    AccountId = 1234,
    
    CreateTime = new DateTime(2016, 7, 9)
};

var str = map.Map(obj);

Here str will be /accounts/1234/2016/07/09/data.json.

Use the StringMap to turn a string into an object:

var str = "/accounts/1234/2016/07/09/data.json";

var obj = map.Map(str);

Here obj will equal the FileKey defined above.

Partial Mapping

Suppose in the above example that you have an AccountId but you do not know the CreateTime:

var fileKey = new FileKey
{
    AccountId = 123,
    
    CreateTime = null // or just omit this for the default of null.
};

You can create a partial string that will be as complete as possible from left to right, stopping once a needed value is null:

var str = map.Map(fileKey, allowPartialMap: true);

Here str will be /accounts/1234/.

Simple Data Types

The data type does not need to be a class, and can instead be a simple data type, e.g. int, Guid, etc. In this case you can use this to refer to the data object itself in the map:

var map = new StringMap<int>("/accounts/{this}");

var str = map.Map(123);

Here str will be /accounts/123.