# Prosemirror Composer (WIP)
**URL:** https://discuss.prosemirror.net/t/prosemirror-composer-wip/3887
**Category:** Show
**Created:** [July 7, 2021, 8:46am UTC](https://discuss.prosemirror.net/t/prosemirror-composer-wip/3887 "2021-07-07T08:46:07Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@jstleger0](https://discuss.prosemirror.net/u/jstleger0)
#### Post date: [July 7, 2021, 8:46am UTC](https://discuss.prosemirror.net/t/prosemirror-composer-wip/3887/1 "2021-07-07T08:46:07Z")
Hello all.
Over the last few years, we have been working on a relatively complex Prosemirror project. As this project developed we ended up thinking about how we structured our code. For the most part our document handlers.
I am sure others are doing similar things. Just wanted to share our approach so far.
**Terms**
We decided to use the terms **Modifier** and **Handler**
- **Modifier** - A modifier function takes a `transaction` and returns a `transaction`.
- **Handler** - A handler function takes the `editorView` and composes the modifier functions and dispatches them.
**The NPM Library (WIP)**
Link - [prosemirror-composer - npm](https://www.npmjs.com/package/prosemirror-composer)
We have created a typed npm module that exports some wrapped functions to get you started. I am still working on the README.md.
**Why**
This approach comes into its own once you start writing your own modifiers as you can write tests for those independently. Ill write some examples sometime soon.
Either way - just wanted to start some communication around the package on npm if people saw it… Keen to hear if people think this is worthwhile once the README is fleshed out a bit more.
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### Author:  [@marijn](https://discuss.prosemirror.net/u/marijn)
#### Post date: [July 7, 2021, 9:42pm UTC](https://discuss.prosemirror.net/t/prosemirror-composer-wip/3887/2 "2021-07-07T21:42:15Z")
Interesting. How are you handling positions from multiple changes? Should positions for subsequent changes refer to the document created by the changes before them (in the argument list to `composeModifiers`), or can they all refer to the initial document?
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### Author:  [@ccorcos](https://discuss.prosemirror.net/u/ccorcos)
#### Post date: [July 20, 2021, 8:31am UTC](https://discuss.prosemirror.net/t/prosemirror-composer-wip/3887/3 "2021-07-20T08:31:20Z")
> [@marijn](#):
>
> can they all refer to the initial document?
It looks like the code does not handle mapping positions from the initial document, but that was what I was hoping for!