luciano/mount
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

[doc]: moving start/stop order above composing states

Browse source
This commit is contained in:
Anatoly 2016-02-23 01:33:49 -05:00
parent f801599f68
commit a1e8e9c8e0
1 changed files with 27 additions and 27 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

54
README.md
View file

@ -28,8 +28,8 @@ _**Alan J. Perlis** from [Structure and Interpretation of Computer Programs](htt
- [Talking States](#talking-states)
- [Value of Values](#value-of-values)
- [The Importance of Being Reloadable](#the-importance-of-being-reloadable)
- [Composing States](#composing-states)
- [Start and Stop Order](#start-and-stop-order)
- [Composing States](#composing-states)
- [Start and Stop Parts of Application](#start-and-stop-parts-of-application)
- [Start an Application Without Certain States](#start-an-application-without-certain-states)
- [Swapping Alternate Implementations](#swapping-alternate-implementations)
@ -231,6 +231,31 @@ Here is a [dev.clj](dev/clj/dev.clj) as an example, that sums up to:
the `(reset)` is then used in REPL to restart / reload application state without the need to restart the REPL itself.
## Start and Stop Order
Since dependencies are "injected" by `require`ing on the namespace level, `mount` **trusts the Clojure compiler** to
maintain the start and stop order for all the `defstates`.
The "start" order is then recorded and replayed on each `(reset)`.
The "stop" order is simply `(reverse "start order")`:
```clojure
dev=> (reset)
08:21:39.430 [nREPL-worker-1] DEBUG mount - << stopping.. nrepl
08:21:39.431 [nREPL-worker-1] DEBUG mount - << stopping.. conn
08:21:39.432 [nREPL-worker-1] DEBUG mount - << stopping.. config
:reloading (app.config app.nyse app.utils.datomic app)
08:21:39.462 [nREPL-worker-1] DEBUG mount - >> starting.. config
08:21:39.463 [nREPL-worker-1] DEBUG mount - >> starting.. conn
08:21:39.481 [nREPL-worker-1] DEBUG mount - >> starting.. nrepl
:ready
```
You can see examples of start and stop flows in the [example app](README.md#mount-and-develop).
## Composing States
Besides calling `(mount/start)` there are other useful ways to start an application:
@ -274,7 +299,7 @@ All of the above is much easier to understand by looking at examples:
This would start off from 5 states, even though the whole application may have many more states available. It would then exclude two states (i.e. `#'foo/c` and `#'bar/d`), then it will pass runtime arguments `{:a 42}`, and finally it will start the remaining three states: `#'foo/a`, `#'foo/b`, `#'baz/e`.
You may notice that `only` takes a set, while `except` takes a vector in this example. This is done intentionally to demonstraate that both these functions can take any collection of states. `Set` would make more sense for most cases though.
You may notice that `only` takes a set, while `except` takes a vector in this example. This is done intentionally to demonstraate that both these functions can take any collection of states. `set` would make more sense for most cases though.
Here is a more "involved" example:
@ -294,31 +319,6 @@ Here is a more "involved" example:
This will do the same thing as the previous example plus it would swap `#'foo/a` with `#'test/a` state and `#'baz/e` with `{:datomic {:uri "datomic:mem://composable-mount"}}` value before starting the application.
## Start and Stop Order
Since dependencies are "injected" by `require`ing on the namespace level, `mount` **trusts the Clojure compiler** to
maintain the start and stop order for all the `defstates`.
The "start" order is then recorded and replayed on each `(reset)`.
The "stop" order is simply `(reverse "start order")`:
```clojure
dev=> (reset)
08:21:39.430 [nREPL-worker-1] DEBUG mount - << stopping.. nrepl
08:21:39.431 [nREPL-worker-1] DEBUG mount - << stopping.. conn
08:21:39.432 [nREPL-worker-1] DEBUG mount - << stopping.. config
:reloading (app.config app.nyse app.utils.datomic app)
08:21:39.462 [nREPL-worker-1] DEBUG mount - >> starting.. config
08:21:39.463 [nREPL-worker-1] DEBUG mount - >> starting.. conn
08:21:39.481 [nREPL-worker-1] DEBUG mount - >> starting.. nrepl
:ready
```
You can see examples of start and stop flows in the [example app](README.md#mount-and-develop).
## Start and Stop Parts of Application
In REPL or during testing it is often very useful to work with / start / stop _only a part_ of an application, i.e. "only these two states".