freesewing/markdown/dev/howtos/code/inject/en.md

title	for	about
Part inheritance	developers	Shows how you can use one part of your pattern as the basis for another

Part inheritance within your own pattern is handled via the inject settings in the pattern configuration. Here is a simple example:

inject: {
  front: "base",
  back: "base",

}

The front and back parts will be injected with the base part. As a result, both the front and back parts will be instantiated with a cloned copy of all the points, paths, and snippets of the base part.

This is a common design pattern where one part builds on another. In our example, we can imagine a T-shirt pattern where the front and back are rather similar, apart from the neckline. So rather than repeating ourselves, we draft a base part and inject that in the front and back parts.

Using inject will cause FreeSewing to always draft the injected part prior to drafting the part it gets injected to. It will, in other words, influece the draft order.

For inheriting parts from other patterns, please refer to Design inheritance.