https://github.com/mgernand/objectdelta
Computes the delta of two object instances.
https://github.com/mgernand/objectdelta
delta difference dotnet dotnet-core object
Last synced: 6 months ago
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Computes the delta of two object instances.
- Host: GitHub
- URL: https://github.com/mgernand/objectdelta
- Owner: mgernand
- License: mit
- Created: 2022-04-12T09:58:46.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2025-03-03T11:47:05.000Z (7 months ago)
- Last Synced: 2025-04-23T12:04:32.311Z (6 months ago)
- Topics: delta, difference, dotnet, dotnet-core, object
- Language: C#
- Homepage:
- Size: 76.2 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# ObjectDelta
A libary that creates a delta of two object instances.
The library is inspired by a blog post of [Daniel Wertheim](https://github.com/danielwertheim) about
producing a delta of two objects of the same type using the library [Structurizer](https://github.com/danielwertheim/structurizer).
Unfortunately [Structurizer](https://github.com/danielwertheim/structurizer) will not provide index information
for properties with a ```null``` value, the property of a collection and for ```null``` collection items.
This information is needed to be able to record object changes from ```null``` to a value and vice versa.
I decided to create a library based on [Structurizer](https://github.com/danielwertheim/structurizer) that fits
my needs for the delta creation.
## Usage
```C#
Customer first = new Customer
{
FirstName = "Sherlock",
LastName = "Olmes",
Address = new Address
{
Street = "Baker Street",
Number = "900",
Zip = "NW1",
City = "London",
Country = "England"
},
Tags = new string[] { "detective", "addict" }
};
Customer second = new Customer
{
FirstName = "Sherlock",
LastName = "Holmes",
Address = new Address
{
Street = "Baker Street",
Number = "221b",
Zip = "NW1",
City = "London",
Country = "England"
},
Tags = new string[] { "detective", "genius", "addict" }
};
ObjectDelta result = ObjectComparer.Compare(first, second);
```
The resulting ```ObjectDelta``` provides a flat list containing the deltas for every property,
inclusing nested properties of complex types (like the ```Address```) and colleection items.
The output of ```ToString()``` of the result of operation above:
```plain
LastName (Olmes => Holmes)
Address (ConsoleApp1.Address => ConsoleApp1.Address)
Address.Number (900 => 221b)
Tags (System.String[] => System.String[])
Tags[1] (addict => genius)
Tags[2] (null => addict)
```
## Structure
This creates a flat structure for types and a flat key-value structure for instances.
### Usage
If you just ant to create the schema of a type just pass it to the ```IStructureBuilder```.
```C#
IStructureBuilder builder = new StructureBuilder();
Structure structure = builder.CreateStructure();
Console.WriteLine(structure.Schema);
```
This will result in a flat list of the property structure of the type ```Customer```.
```plain
FirstName
LastName
Address
Address.Street
Address.Number
Address.Zip
Address.City
Address.Country
Tags
```
To create the schema and accessors for the values of an instance pass the instance to the ```IStructureBuilder```.
```C#
Customer customer = new Customer
{
FirstName = "Sherlock",
LastName = "Holmes",
Address = new Address
{
Street = "Baker Street",
Number = "221b",
Zip = "NW1",
City = "London",
Country = "England"
},
Tags = new string[] { "detective", "addict" }
};
IStructureBuilder builder = new StructureBuilder();
Structure structure = builder.CreateStructure(customer);
Console.WriteLine(structure.Indices);
```
This will result in a flat list of the property values in the given instance of type ```Customer```.
```plain
FirstName = "Sherlock"
LastName = "Holmes"
Address = "ConsoleApp1.Address"
Address.Street = "Baker Street"
Address.Number = "221b"
Address.Zip = "NW1"
Address.City = "London"
Address.Country = "England"
Tags = "System.String[]"
Tags[0] = "detective"
Tags[1] = "addict"
```
## Acknowledgement
Most of the terminology and code structure of the library comes from the libary [Structurizer](https://github.com/danielwertheim/structurizer)
by [Daniel Wertheim](https://github.com/danielwertheim). This is basically a fork of his work which I bent to my needs, f.e. the need
to support ```null``` values in index values and some other fixes and tweaks. I completely remove the configuration part and added the
ability to just get the schema of a type. The library this work is based on is licensed under the MIT license and so it this library.
## References
[Daniel Wertheim](https://github.com/danielwertheim)
- [Structurizer](https://github.com/danielwertheim/structurizer)
- [How to build a simple object graph delta comparer in C# using Structurizer](https://danielwertheim.se/how-to-build-a-simple-object-graph-delta-comparer-in-csharp-using-structurizer/)