add import/export feature for preferences

README.md

@@ -30,7 +30,6 @@ Community instances:
 
 ## TODO
 
-* Import/export preferences
 * User trophies
 * "other discussions" feature
 * "Open on reddit" links

routes.js

@@ -29,6 +29,42 @@ module.exports = (app, redis, fetch, RedditAPI) => {
     return res.redirect('/preferences')
   })
   
+  app.get('/import_prefs/:key', (req, res, next) => {
+    let key = req.params.key
+    if(!key)
+      return res.redirect('/')
+    if(key.length !== 10)
+      return res.redirect('/')
+    
+    key = `prefs_key:${key}`
+    redis.get(key, (error, json) => {
+      if(error) {
+        console.error(`Error getting the preferences import key ${key} from redis.`, error)
+        return res.render('index', { json: null, user_preferences: req.cookies })
+      }
+      if(json) {
+        try {
+          let prefs = JSON.parse(json)
+          let subbed_subreddits_is_set = false
+          for(var setting in prefs) {
+            if(prefs.hasOwnProperty(setting)) {
+              res.cookie(setting, prefs[setting], { maxAge: 365 * 24 * 60 * 60 * 1000, httpOnly: true })
+              if(setting === 'subbed_subreddits')
+                subbed_subreddits_is_set = true
+            }
+          }
+          if(!subbed_subreddits_is_set)
+            res.clearCookie('subbed_subreddits')
+          return res.redirect('/preferences')
+        } catch(e) {
+          console.error(`Error setting imported preferences to the cookies. Key: ${key}.`, error)
+        }
+      } else {
+        return res.redirect('/preferences')
+      }
+    })
+  })
+
   app.get('/privacy', (req, res, next) => {
     return res.render('privacypolicy', { user_preferences: req.cookies })
   })
@@ -1225,6 +1261,19 @@ module.exports = (app, redis, fetch, RedditAPI) => {
     return res.redirect('/preferences')
   })
   
+  app.post('/export_prefs', (req, res, next) => {
+    let r = `${(Math.random().toString(36)+'00000000000000000').slice(2, 10+2).toUpperCase()}`
+    let key = `prefs_key:${r}`
+    redis.set(key, JSON.stringify(req.cookies), (error) => {
+      if(error) {
+        console.error(`Error saving preferences to redis.`, error)
+        return res.redirect('/preferences')
+      } else {
+        return res.render('preferences', { user_preferences: req.cookies, instance_config: config, preferences_key: r })
+      }
+    })
+  })
+
   app.post('/r/:subreddit/comments/:id/:snippet', (req, res, next) => {
     /* morechildren route */
     let all_ids = req.body.all_ids

static/css/styles.css

@@ -150,6 +150,12 @@ form .setting {
   margin: 10px 0;
   width: 100%;
 }
+#export-form {
+  margin: 60px 0px 0px 0px;
+}
+#export-form input {
+  margin: 10px 0px 10px 0px;
+}
 .container .content small.notice {
   padding-top: 20px;
   padding-bottom: 5px;

views/preferences.pug

@@ -67,4 +67,27 @@ html
           small(class="notice") Preferences are stored client-side using cookies without any personal information.
           input(type="submit", value="Save preferences")
           a(href="/resetprefs", class="btn") Reset preferences
+        form(action="/export_prefs", method="POST", id="export-form")
+          if preferences_key
+            details(open)
+              summary
+                span Export preferences
+              .setting
+                small By exporting your preferences you can transfer your subscribed subreddits and preferences to another device. Or you could create a bookmark if you tend to delete your cookies frequently.
+                br
+                input(type="submit", value="Export preferences")
+                if preferences_key
+                  - var protocol = 'http'
+                  if instance_config.https_enabled === true
+                    - var protocol = 'https'
+                  p Visit this URL to import your preferences:
+                  a(href=`${protocol}://${instance_config.domain}/import_prefs/${preferences_key}`) #{protocol}://#{instance_config.domain}/import_prefs/#{preferences_key}
+          else
+            details
+              summary
+                span Export preferences
+              .setting
+                small By exporting your preferences you can transfer your subscribed subreddits and preferences to another device. Or you could create a bookmark if you tend to delete your cookies frequently.
+                br
+                input(type="submit", value="Export preferences")
     include includes/footer.pug