# diff-patch
## Introduction
diff-patch is a library that exposes two functions, `diff` and `patch`.
The library does not have any dependencies.
The `diff` function takes two objects (`obj1` and `obj2`) and deep compares them, returning an object that represents the difference between the two (the `diffData`).
`diffData` is an object that can be used to apply the diff to `obj1` to get an object that is the same as `obj2`.
The `patch` function takes an `obj` and a `diffData` object and applies the diff to the object, returning a new object.
The `diff` and `patch` functions are implemented in the following languages:
* TypeScript
* Python3
The `diffData` object **can be used interchangeably between the languages**.\
This makes this library very useful for networked applications, where the client and server are written in different languages.
`diffData` can be serialized to JSON and deserialized back to an object. It aims to be as small as possible, and is designed to be used in a networked environment.
More languages will be added in the future, contributions are welcome.
## Usage
To install the Python3 version of diff-patch, run:
```bash
pip install fsoft-diff-patch
```
Then, in your Python code:
```python
from fsoft_diff_patch import diff, patch
obj1 = {
'a': 1,
'b': 2,
'c': {
'd': 3,
'e': 4,
},
}
obj2 = {
'a': 1,
'b': 2,
'c': {
'd': 3,
'e': 5, # changed
},
}
# create the diff data
diff_data = diff(obj1, obj2)
# show the diff data for debugging
print("diff_data: ", diff_data)
# apply the diff data to obj1 to get an object that is the same as obj2
obj3 = patch(obj1, diff_data)
# show the result for debugging
print("obj3: ", obj3)
```
### Hint
The `diff` function can be used to see if two objects are the same, by comparing the result of `diff` to an empty object.
```python
from diff_patch import diff
obj1 = {
'a': 1,
'b': 2,
'c': {
'd': 3,
'e': 4,
},
}
obj2 = {
'a': 1,
'b': 2,
'c': {
'd': 3,
'e': 4,
},
}
diff_data = diff(obj1, obj2)
# if the objects are the same, diff_data will be an empty object
if not diff_data:
print("The objects are the same")
```
## Contributors
This library was created by [Fabio Rotondo](https://github.com/fsoft72).
New language implementations are more than welcome.\
Please open an issue or a pull request if you want to contribute.
**Collaborators**:
* [Nikola Gluhovic](https://github.com/nini-os)
The official repository for this library is [here](https://github.com/fsoft72/diff-patch).
## License
This library is licensed under the MIT License.\
See the [LICENSE](LICENSE) file for details.
