From 33ca0c1915c3a6fefd4e643e9e4a8f30d46b5d5e Mon Sep 17 00:00:00 2001
From: Josh Perez <josh@goatslacker.com>
Date: Tue, 5 May 2015 10:51:22 -0700
Subject: [PATCH] An opinionated way of doing async with alt

---
 src/alt/utils/StoreMixins.js | 33 ++++++++++++++++++
 src/alt/utils/StoreUtils.js  |  4 +++
 src/utils/decorators.js      |  8 +++++
 stargazer.js                 | 67 ++++++++++++++++++++++++++++++++++++
 4 files changed, 112 insertions(+)
 create mode 100644 stargazer.js

diff --git a/src/alt/utils/StoreMixins.js b/src/alt/utils/StoreMixins.js
index ab52e6f0..e365de28 100644
--- a/src/alt/utils/StoreMixins.js
+++ b/src/alt/utils/StoreMixins.js
@@ -25,6 +25,39 @@ export const StoreMixinEssentials = {
     this.dispatcher.waitFor(tokens)
   },
 
+  exportAsync(asyncMethods) {
+    const toExport = Object.keys(asyncMethods).reduce((publicMethods, methodName) => {
+      const asyncSpec = asyncMethods[methodName]
+
+      const validHandlers = ['success', 'error', 'loading']
+      validHandlers.forEach((handler) => {
+        if (asyncSpec[handler] && !asyncSpec[handler][ACTION_KEY]) {
+          throw new Error(`${handler} handler must be an action function`)
+        }
+      })
+
+      publicMethods[methodName] = (...args) => {
+        const state = this.getInstance().getState()
+        const value = asyncSpec.cache(state, ...args)
+
+        // if we don't have it in cache then fetch it
+        if (!value) {
+          if (asyncSpec.loading) asyncSpec.loading()
+          asyncSpec.fetch(state, ...args)
+            .then(asyncSpec.success)
+            .catch(asyncSpec.error)
+        } else {
+          // otherwise emit the change now
+          this.emitChange()
+        }
+      }
+
+      return publicMethods
+    }, {})
+
+    this.exportPublicMethods(toExport)
+  },
+
   exportPublicMethods(methods) {
     Object.keys(methods).forEach((methodName) => {
       if (typeof methods[methodName] !== 'function') {
diff --git a/src/alt/utils/StoreUtils.js b/src/alt/utils/StoreUtils.js
index c514635e..e9b6b6eb 100644
--- a/src/alt/utils/StoreUtils.js
+++ b/src/alt/utils/StoreUtils.js
@@ -135,6 +135,10 @@ export function createStoreFromClass(alt, StoreModel, key, ...argsForClass) {
 
   const store = new Store(...argsForClass)
 
+  if (config.datasource) {
+    StoreMixinEssentials.exportAsync.call(Store.prototype, config.datasource)
+  }
+
   storeInstance = assign(
     new AltStore(
       alt,
diff --git a/src/utils/decorators.js b/src/utils/decorators.js
index 9e6345d1..2fa302f2 100644
--- a/src/utils/decorators.js
+++ b/src/utils/decorators.js
@@ -9,3 +9,11 @@ export function createStore(alt, ...args) {
     return alt.createStore(Store, undefined, ...args)
   }
 }
+
+export function datasource(source) {
+  return function (Store) {
+    Store.config = Store.config || {}
+    Store.config.datasource = source
+    return Store
+  }
+}
diff --git a/stargazer.js b/stargazer.js
new file mode 100644
index 00000000..8e98a595
--- /dev/null
+++ b/stargazer.js
@@ -0,0 +1,67 @@
+import Alt from './'
+import { createStore, datasource } from './utils/decorators'
+import axios from 'axios'
+
+const alt = new Alt()
+
+const StargazerActions = alt.generateActions(
+  'fetchingUsers',
+  'usersReceived',
+  'failed'
+)
+
+const StargazerSource = {
+  fetchUsers: {
+    fetch(state) {
+      const url = `https://api.github.com/repos/${state.user}/${state.repo}/stargazers`
+      return axios({ url }).then(response => response.data)
+    },
+
+    cache(state) {
+      return state.users.length ? state.users : null
+    },
+
+    loading: StargazerActions.fetchingUsers,
+
+    success: StargazerActions.usersReceived,
+
+    error: StargazerActions.failed
+  }
+}
+
+@createStore(alt)
+@datasource(StargazerSource)
+class StargazerStore {
+  constructor() {
+    this.user = 'goatslacker'
+    this.repo = 'alt'
+    this.users = []
+    this.errorMessage = null
+    this.isLoading = false
+
+    this.bindListeners({
+      loading: StargazerActions.fetchingUsers,
+      receivedUsers: StargazerActions.usersReceived,
+      failed: StargazerActions.failed
+    })
+  }
+
+  loading() {
+    console.log('STORE: starting to load users')
+    this.isLoading = true
+  }
+
+  failed(e) {
+    console.log('STORE: Uh oh')
+    this.errorMessage = e.statusText || String(e)
+  }
+
+  receivedUsers(users) {
+    console.log('STORE: got users')
+    this.users = users
+    this.errorMessage = null
+  }
+}
+
+StargazerStore.listen((state) => console.log('CHANGED', state.users.length))
+StargazerStore.fetchUsers()