update readme

README.md

@@ -18,16 +18,15 @@ In the `splash.html` file
  * 3. Launches a window pointed to the latest version
  */
 nwSplasherAutoUpdate.downloadLatestAppAndOpenWindowInBackground({
-  // OPTIONAL: defaults to true
+  // OPTIONAL: defaults to true, will not show console messages if false
   verbose: true,
   /**
-   * OPTIONAL: console.error is called by default if verbose: true.
+   * OPTIONAL: Your own custom logging function called with helpful
+   * warning/error messages from the internal validators. Only used if
+   * verbose: true. Defaults to console.error if not supplied.
    *
-   * Your own custom logging function called with helpful warning/error
-   * messages from the internal validators. Only used if verbose: true.
-   *
-   * @param  {string} message The human readable warning/error message
-   * @param  {object} error   Sometimes an error or options object is passed
+   * @param string} message  The human readable warning/error message
+   * @param object} error    Sometimes an error or options object is passed
    */
   customLogger: function (message, error) {
     console.log(message, error);
@@ -51,20 +50,24 @@ nwSplasherAutoUpdate.downloadLatestAppAndOpenWindowInBackground({
      * then pass the response into the confirmNewVersion and downloadPath
      * callback functions you provide.
      */
-    // This is an example, you can put whatever URL you want here
+    // This is an example, you can put whatever URL you want here, does not need to be JSON.
     versionUrl: 'https://example.com/versions.json',
     /**
-     * Check if the latest remote version is newer than the latest local version.
+     * This function is handed the response from the versionUrl request, and the version number
+     * of the latest locally installed version of your app. You can then perform whatever logic
+     * you want (including additional network calls) to determine wether to download a new
+     * version of your app or to use the local copy.
+     *
      * If a new version is available, return the new version number to begin the
      * download/extract. If no new version exists, then return false and the latest
      * local version will be opened in a new window and the splash screen closed.
      *
-     * @param  {string}  response     The network respone from versionUrl
-     * @param  {string}  latestLocal  The latest downloaded version, or undefined if not present
-     * @return {string}               The new version number (continue to download zip), or false (open current version)
+     * @param  {string} response     The network respone from versionUrl
+     * @param  {string} latestLocal  The latest downloaded version, or undefined if not present
+     * @return {string}              The new version number (continue to download zip), or false (open current version)
      */
     confirmNewVersion: function (response, latestLocal) {
-      //This is just an example, you can put any logic you want here
+      // This is just an example, you can put any logic you want here
       response = JSON.parse(response);
       const latestRemote = response.latest.version;
       const updateAvailable = require('semver').gt(latestRemote, latestLocal);
@@ -81,22 +84,23 @@ nwSplasherAutoUpdate.downloadLatestAppAndOpenWindowInBackground({
      * @return {string}           A url to a ZIP file to be downloaded
      */
     downloadPath: function (response) {
-      //This is just an example, you can put any logic you want here
+      // This is just an example, you can put any logic you want here
       response = JSON.parse(response);
       return response.latest.downloadUrl;
     },
-    // If the download or extract fails, we will retry n times before stopping
+    // If the download or extract fails, we will retry the following amount of times before stopping
     downloadRetries: 3,
     extractRetries: 3,
     /**
-     * Called when an update occurs during download/extract.
+     * Optional event hook.
+     * Called when an update occurs during download/extract. May be called many times.
      *
-     * @param  {object} update                   Object containing percents
-     * @param  {number} update.downloadProgress  The download progress percent
-     * @param  {number} update.extractProgress   The extract progress percent
+     * @param {object} update                   Object containing percents
+     * @param {number} update.downloadProgress  The download progress percent
+     * @param {number} update.extractProgress   The extract progress percent
      */
     onUpdate: function ({ downloadProgress, extractProgress }) {
-      //This is just an example, you can put any logic you want here
+      // This is just an example, you can put any logic you want here
       if (downloadProgress) {
         console.log('Download progress: ' + downloadProgress + '%');
       }
@@ -107,40 +111,42 @@ nwSplasherAutoUpdate.downloadLatestAppAndOpenWindowInBackground({
     /**
      * Optional function. You can run any code to validate
      * that the downloaded zip matches expecations.
-     * If it does return true. If you return false, then
-     * nwSplasherAutoUpdate will retry or stop running.
+     * If it does, return true. If you return false, then
+     * nwSplasherAutoUpdate will retry the download or stop running.
      *
      * @param  {string}  pathToZip  File path to the downloaded zip file
      * @return {Boolean}            true = continue, false = retry/stop
      */
     validateZip: function (pathToZip) {
-      //This is just an example, you can put any logic you want here
+      // This is just an example, you can put any logic you want here
       return true;
     },
     /**
      * Optional function. You can run any code to validate
      * that the files extracted from the zip match your
-     * expecations. If they do return true. If you return false,
-     * then nwSplasherAutoUpdate will retry or stop running.
+     * expecations. If they do, return true. If you return false,
+     * then nwSplasherAutoUpdate will retry extraction or stop running.
      *
-     * @param  {string}  pathToExtract  File path to the downloaded zip file
+     * @param  {string}  pathToExtract  File path to extracted folder
      * @return {Boolean}                true = continue, false = retry/stop
      */
     validateExtract: function (pathToExtract) {
-      //This is just an example, you can put any logic you want here
+      // This is just an example, you can put any logic you want here
       return true;
     },
     /**
+     * Optional event hook.
      * When download or extract fails, but we haven't
      * exhausted all retries yet, this is called.
      *
      * @param {string} message  Human readable warning message
      */
     onRetry: function (message) {
-      //This is just an example, you can put any logic you want here
+      // This is just an example, you can put any logic you want here
       console.log(message);
     },
     /**
+     * Optional event hook.
      * Called when an error is encountered that ended execution
      * prematurely. Such as failing to download or extract after
      * all retries were exhausted.
@@ -149,10 +155,11 @@ nwSplasherAutoUpdate.downloadLatestAppAndOpenWindowInBackground({
      * @param {object} err           Detailed error information if available
      */
     onError: function (errorMessage, err) {
-      //This is just an example, you can put any logic you want here
+      // This is just an example, you can put any logic you want here
       console.log(errorMessage, err);
     },
     /**
+     * Optional event hook.
      * Called just prior to opening the new window
      * and closing the splash screen.
      */
@@ -172,14 +179,17 @@ nwSplasherAutoUpdate.downloadLatestAppAndOpenWindowInBackground({
 });
 ```
 
-In your main window that is displayed after the auto-update
+In your main window that is displayed after the auto-update (probably `index.html`);
 
-```js
+```html
+<script>
+const nwSplasherAutoUpdate = require('nw-splasher-auto-update');
 nwSplasherAutoUpdate.setCurrentWorkingDirectory();
 nwSplasherAutoUpdate.closeSplashAndShowApp({
   // Must match the port number used in the splash.html
   port: 4443
 });
+</script>
 ```
 
 
@@ -193,6 +203,7 @@ Deleting old cache
  */
 nwSplasherAutoUpdate.deletePastVersions({
   /**
+   * Optional event hook.
    * Called when any errors are encountered during deletion.
    *
    * @param {string} errorMessage  Human readable error message
@@ -202,6 +213,7 @@ nwSplasherAutoUpdate.deletePastVersions({
     console.log(errorMessage, err);
   },
   /**
+   * Optional event hook.
    * When deletion attempt finishes, whether successful or not.
    */
   onComplete: function () {
@@ -231,7 +243,7 @@ path.join(nw.App.dataPath, 'nwSplasherExtracts', version);
 * Would use `nw-splasher` as a dependency
 * Would use `fs-extra` to delete files
 * Not sure what to use for network requests (versions.json), downloading zip (including progress updates), or extracting the zip file (including progress updates)
-* We have a lot of beginner programmers. So although internally we may use async/await and promises, I'd like the API to be kept as a simple/approachable object with callbacks to be more approachable
+* We have a lot of beginner programmers. So although internally we may use async/await and promises, I'd like to keep the API as a simple object with callbacks to be more approachable
 * There are a lot of other features we might want to add in the future, like support for `.tar.gz`, `.rar`, `.7z`, etc but let's keep the scope small for now until those features are requested.
 
 
@@ -242,8 +254,12 @@ path.join(nw.App.dataPath, 'nwSplasherExtracts', version);
 nwSplasherAutoUpdate.downloadLatestAppAndOpenWindowInBackground({
   autoUpdate: {
     versionUrl: 'https://example.com/versions.json',
-    confirmNewVersion: function (response, latestLocal) {},
-    downloadPath: function (response) {}
+    confirmNewVersion: function (response, latestLocal) {
+      return true || false;
+    },
+    downloadPath: function (response) {
+      return 'url to download zip file containing new app version'
+    }
   }
 });
 
@@ -272,6 +288,14 @@ If they release different auto-update packages for different NW.js versions.
 We suggest ALL users of this library code in some UI to convey to users when an auto-update won't work, and they'll need to download the full version from the website again. So if a user is on a 3 year old version of NW.js that you want to drop support for, there is some way of conveying that cleanly in the UI that is compatible with the older version.
 
 
+## How can I force the user to update to a newer NW.js version?
+
+Two ways:
+
+* **Thinking ahead:** Include some code in the splasher window to look at your end point response, notice a flag, and then display a message with a link "You must manually download and install the latest version", then the link opens in the user's default browser with `nw.Shell.openExternal('https://expample.com/download')`.
+* **Not thinking ahead:** If you didn't preemptively include a way of handling this case, you can instead have the latest version of the app just be a window that directs people to download a new version. The new version's splasher could then be better designed to handle this scenario.
+
+
 ### For-profit software
 
 If you are using NW.js to create for-profit software, then this style of auto-update may not work for you. If you require authenticating a license, key, or the user, or the download requires authentication, then this "splash + download a zip" approach is likely too simple for your needs, and you should consider writing your own solution custom to your use case.