Add comments.

app/scripts/controllers/address-book.js

@@ -3,6 +3,10 @@ const extend = require('xtend')
 
 class AddressBookController {
 
+
+  // Controller in charge of managing the address book functionality from the
+  // recipients field on the send screen. Manages a history of all saved
+  // addresses and all currently owned addresses.
   constructor (opts = {}) {
     const initState = extend({
       addressBook: [],
@@ -14,8 +18,9 @@ class AddressBookController {
   // PUBLIC METHODS
   //
 
+  // Sets a new address book in store by accepting a new address and nickname.
   setAddressBook (address, name) {
-    return this.addToAddressBook(address, name)
+    return this._addToAddressBook(address, name)
     .then((addressBook) => {
       this.store.updateState({
         addressBook,
@@ -24,8 +29,16 @@ class AddressBookController {
     })
   }
 
-  addToAddressBook (address, name) {
+  //
-    let addressBook = this.getAddressBook()
+  // PRIVATE METHODS
+  //
+
+
+  // Performs the logic to add the address and name into the address book. The
+  // pushed object is an object of two fields. Current behavior does not set an
+  // upper limit to the number of addresses.
+  _addToAddressBook (address, name) {
+    let addressBook = this._getAddressBook()
     let index = addressBook.findIndex((element) => { return element.address === address || element.name === name })
     if (index !== -1) {
       addressBook.splice(index, 1)
@@ -37,7 +50,9 @@ class AddressBookController {
     return Promise.resolve(addressBook)
   }
 
-  getAddressBook () {
+  // Internal method to get the address book. Current persistence behavior
+  // should not require that this method be called from the UI directly.
+  _getAddressBook () {
     return this.store.getState().addressBook
   }
 

ui/app/actions.js

@@ -698,6 +698,7 @@ function setRpcTarget (newRpc) {
   }
 }
 
+// Calls the addressBookController to add a new address. 
 function addToAddressBook (recipient, nickname) {
   log.debug(`background.addToAddressBook`)
   return (dispatch) => {

ui/app/components/ens-input.js

@@ -47,11 +47,13 @@ EnsInput.prototype.render = function () {
     style: { width: '100%' },
   }, [
     h('input.large-input', opts),
+    // The address book functionality.
     h('datalist',
       {
         id: 'addresses',
       },
       [
+        // Corresponds to the addresses owned.
         Object.keys(props.identities).map((key) => {
           let identity = props.identities[key]
           return h('option', {
@@ -59,6 +61,7 @@ EnsInput.prototype.render = function () {
             label: identity.name,
           })
         }),
+        // Corresponds to previously sent-to addresses.
         props.addressBook.map((identity) => {
           return h('option', {
             value: identity.address,
@@ -118,6 +121,8 @@ EnsInput.prototype.lookupEnsName = function () {
 EnsInput.prototype.componentDidUpdate = function (prevProps, prevState) {
   const state = this.state || {}
   const ensResolution = state.ensResolution
+  // If an address is sent without a nickname, meaning not from ENS or from
+  // the user's own accounts, a default of a one-space string is used.
   const nickname = state.nickname || ' '
   if (ensResolution && this.props.onChange &&
       ensResolution !== prevState.ensResolution) {