added test for privacy Cache API block

Author: optimalisatie

LICENSE.json

@@ -0,0 +1,22 @@
+{
+    "name": "cache-api-keyval-store",
+    "version": "1.0.0",
+    "description": "Cache API key/value store with expiration and JSON object storage.",
+    "author": {
+        "name": "info@optimization.team",
+        "email": "info@optimization.team",
+        "web": "optimization.team"
+    },
+    "engines": {
+        "node": "~0.10"
+    },
+    "dependencies": {
+
+    },
+    "devDependencies": {
+        "grunt": "latest",
+        "grunt-closure-compiler": "latest",
+        "matchdep": "latest",
+        "merge": "latest"
+    }
+}

README.md

@@ -2,7 +2,7 @@
 
 # Cache API Key/Value Store
 
-Fast and tiny key/value store with +50MB storage capacity in [most browsers](https://developer.mozilla.org/en-US/docs/Web/API/Cache#Browser_compatibility), expiration and JSON object data-type.
+Fast and tiny key/value store with +50MB storage capacity in [most browsers](https://developer.mozilla.org/en-US/docs/Web/API/Cache#Browser_compatibility), expiration and JSON object data-type support.
 
 Cache API is currently available in Chrome >= 40, Firefox >=39 and Opera >= 27.
 
@@ -20,29 +20,33 @@ npm install --save cache-api-keyval
 <script src="/cache-api-keyval.js"></script>
 <script>
 
-// load database
-var db = new CacheApiDB('my-store', { namespace: 'optional' });
+// wait for Cache API accessibility test to complete
+onCacheApiDB(function() {
 
-if (db.supported) { // Cache API supported by browser
+    // load database
+    var db = new CacheApiDB('my-store', { namespace: 'optional' });
 
-    // set JSON object data
-    db.set('key', { json: 'object' }); 
+    if (db.supported) { // Cache API supported by browser
 
-    // set text data with expiration in 24 hours
-    db.set('key2', 'string', 86400); 
+        // set JSON object data
+        db.set('key', { json: 'object' }); 
 
-    // get data from cache
-    db.get('key').then(function(json) {
-        console.log('json object', json);
-    });
+        // set text data with expiration in 24 hours
+        db.set('key2', 'string', 86400); 
 
-    // delete key from database
-    db.del('key2'); 
+        // get data from cache
+        db.get('key').then(function(json) {
+            console.log('json object', json);
+        });
 
-    // prune expired cache entries
-    db.prune();
+        // delete key from database
+        db.del('key2'); 
 
-}
+        // prune expired cache entries
+        db.prune();
+    }
+
+});
 </script>
 ```
 

cache-api-keyval.ext.js

@@ -1,7 +1,8 @@
 // Closure Compiler externs
 // @link https://developers.google.com/closure/compiler/
 
-window.CacheApiDB = global.CacheApiDB = this.CacheApiDB = self.CacheApiDB = function(store, options) {
+var global;
+window.CacheApiDB = global.CacheApiDB = this.CacheApiDB = self.CacheApiDB = window.onCacheApiDB = global.onCacheApiDB = this.onCacheApiDB = self.onCacheApiDB = function(store, options) {
 
     options.namespace = '';
 

dist/cache-api-keyval.js

@@ -1,6 +1,6 @@
 {
     "name": "cache-api-keyval",
-    "version": "1.0.5",
+    "version": "1.0.6",
     "description": "Browser Cache API key/value store with +50MB capacity, expiration and JSON object data-type storage.",
     "author": {
         "name": "info@optimization.team",

package.json

@@ -1,5 +1,5 @@
 /**
- * Cache API key/value store - github.com/optimalisatie
+ * Cache API key/value store - github.com/optimalisatie/Cache-API-Key-Value-Store
  * Released under the terms of MIT license
  *
  * Copyright (C) 2018 github.com/optimalisatie
@@ -9,30 +9,70 @@
 
     var _root = ("undefined" != typeof window ? window : "undefined" != typeof global ? global : "undefined" != typeof self ? self : this);
 
-    // detect Cache API support
-    if (!(caches instanceof CacheStorage)) {
-        var error = 'Browser does not support Cache API';
+    function print_error(msg) {
         if (console) {
-            console.error(error);
+            console.error(msg);
         }
-        _root.CacheApiDB = (_root.CacheApiDBFallback) ? _root.CacheApiDBFallback() : function() {
+    }
+
+    var queue = [];
+    _root.onCacheApiDB = function(callback) {
+        if (_root.CacheApiDB) {
+            callback();
+        } else {
+            queue.push(callback);
+        }
+    }
+
+    // set cache api db controller
+    function setCacheApiDB(factory) {
+
+        _root.CacheApiDB = factory;
+
+        // process callback queue
+        var callback = queue.shift();
+        while (callback) {
+            callback();
+        }
+    }
+
+    if (!_root.CacheApiDBFallback) {
+        _root.CacheApiDBFallback = function() {
             var that = this;
             that.supported = 0;
             ['get', 'set', 'del', 'prune'].forEach(function(method) {
                 that[method] = function() {
                     return Promise.reject(error);
                 }
             });
-        };
+        }
+    }
+
+    // detect Cache API support
+    if (!(caches instanceof CacheStorage)) {
+        print_error('Browser does not support Cache API');
+        _root.CacheApiDB = _root.CacheApiDBFallback;
     } else {
-        _root.CacheApiDB = factory();
+
+        // test cache support
+        // Cache API could be blocked by browser privacy settings
+        caches.open('x').catch(function(e) {
+            if (e.name == 'SecurityError') {
+                print_error('Cache API is blocked by browser. Please check privacy settings (cookies, no-track option etc).');
+            } else {
+                print_error('Cache API error: ' + e.message);
+            }
+            setCacheApiDB(_root.CacheApiDBFallback);
+        }).then(function() {
+            setCacheApiDB(factory());
+        })
+
     }
 })(function() {
 
     var DATE_HEADER = 'x-date';
     var EXPIRE_HEADER = 'x-expire';
     var CONTENT_TYPE_HEADER = 'Content-Type';
-    var CONTENT_TYPE_JSON = 'application/json';
 
     // return timestamp
     function NOW() {
@@ -62,10 +102,7 @@
                     return false;
                 }
 
-                // detect content type
-                var json = cachedata.headers.get(CONTENT_TYPE_HEADER) === CONTENT_TYPE_JSON;
-
-                return (json) ? cachedata.json() : cachedata.text();
+                return cachedata.json();
             });
 
         });
@@ -82,17 +119,9 @@
             // cache date
             cache_headers[DATE_HEADER] = NOW();
 
-            // JSON content type
-            if (IS_OBJECT(data)) {
-
-                // JSON
-                cache_headers[CONTENT_TYPE_HEADER] = CONTENT_TYPE_JSON;
-                data = JSON.stringify(data);
-            } else {
-                // string
-                data = STRING(data);
-                cache_headers[CONTENT_TYPE_HEADER] = 'text/plain'
-            }
+            // JSON
+            cache_headers[CONTENT_TYPE_HEADER] = 'application/json';
+            data = JSON.stringify(data);
 
             // expire time
             if (expire) {