re-frame provides a data driven architecture, but we need to be able to inspect it. re-frame-trace takes inspiration from [redux-devtools](https://github.com/gaearon/redux-devtools), and provides several ways to visualise the structure and state of your re-frame application.
If you are using leiningen, modify `project.clj` in the following ways. When puzzling over the various possible leiningen configurations, it's often helpful to look at a sample [project.clj](https://github.com/technomancy/leiningen/blob/stable/sample.project.clj).
re-frame has instrumentation to collect traces throughout various important points in the lifecycle of a re-frame app. re-frame-trace is a consumer of these traces, and provides visualisations of the traces. These traces have a well-defined structure, and will eventually be standardised, allowing other developers to create their own tooling to work against the traces. Currently, re-frame's tracing and re-frame-trace are in alpha and are subject to change at any time.
By default, re-frame tracing is compiled out, so it won't impose a performance cost in production. The trade-off here is that you need to explicitly enable it in development.
The [preloads](https://github.com/clojure/clojurescript/wiki/Compiler-Options#preloads) option (`:preloads [day8.re-frame.trace.preload]`) has to be set in order to automatically monkeypatch Reagent to add appropriate lifecycle hooks. Yes this is gross, and yes we will try and make a PR to reagent to add proper hooks, once we know exactly what we need. The preload namespace also injects a div containing the devtools panel into the DOM.
You need both the re-frame-trace project _and_ a test project to develop it against. For example, you can use the [todo-mvc](https://github.com/Day8/re-frame/tree/master/examples/todomvc) project.
- Clone `re-frame-trace` to your machine:
```
git clone git@github.com:Day8/re-frame-trace.git
```
- Go into the root folder of the test project you're using to develop re-frame-trace with.
```
cd /your/project/folder
```
- Add re-frame-trace into this test project using the [instructions](#getting-started) above.
- Still in the test project, create a folder called `checkouts`, then enter the folder:
- Create a [relative symlink](https://superuser.com/questions/146231/how-do-i-create-a-relative-symbolic-link-in-linux) from your local re-frame-trace project in the checkouts folder. For example:
- If you're using figwheel in the test project, you need to add the checkouts folder (`checkouts/re-frame-trace/src`) to `:cljsbuild :source-paths` in the `project.clj` file. If you're having trouble locating the right place to put this, it might help to look to a sample [project.clj](https://github.com/technomancy/leiningen/blob/stable/sample.project.clj) for inspiration. For example:
