storage: add promptSaveAs option to getSignedUrl

Author: mziccard

lib/storage/file.js

@@ -1019,9 +1019,13 @@ File.prototype.getSignedPolicy = function(options, callback) {
  *     link will expire.
  * @param {string=} options.extensionHeaders - If these headers are used, the
  *     server will check to make sure that the client provides matching values.
+ * @param {string=} options.promptSaveAs - If you provide this value the SaveAs 
+ *     prompt will be displayed when accessing the signed url and the file name 
+ *     will be set to the provided value. If options.responseDisposition is set 
+ *     this option is ignored.
  * @param {string=} options.responseDisposition - If you provide this value, 
- *     the response-content-disposition parameter of the signed url is set 
- *     accordingly.
+ *     the response-content-disposition parameter (http://goo.gl/yMWxQV) of the 
+ *     signed url is set accordingly.
  * @param {string=} options.responseType - If you provide this value, the 
  *     response-content-type parameter of the signed url is set accordingly.
  * @param {function=} callback - The callback function.
@@ -1030,7 +1034,7 @@ File.prototype.getSignedPolicy = function(options, callback) {
  * file.getSignedUrl({
  *   action: 'read',
  *   expires: Math.round(Date.now() / 1000) + (60 * 60 * 24 * 14), // 2 weeks.
- *   responseDisposition: 'attachment; filename="filename.ext"'
+ *   promptSaveAs: 'filename.ext'
  * }, function(err, url) {});
  */
 File.prototype.getSignedUrl = function(options, callback) {
@@ -1074,7 +1078,18 @@ File.prototype.getSignedUrl = function(options, callback) {
     }
 
     var responseContentDisposition = '';
+    if (util.is(options.promptSaveAs, 'string')) {
+      responseContentDisposition =
+        '&response-content-disposition=attachment; filename="' + 
+        encodeURIComponent(options.promptSaveAs) + '"';
+    }
     if (util.is(options.responseDisposition, 'string')) {
+      if (responseContentDisposition !== '') {
+        console.warn([
+          'getSignedUrl: the promptSaveAs option is ignored',
+          'when responseDisposition is provided.'
+        ].join(' '));
+      }
       responseContentDisposition = 
         '&response-content-disposition=' + 
         encodeURIComponent(options.responseDisposition);

test/storage/file.js

@@ -1350,27 +1350,63 @@ describe('File', function() {
       });
     });
 
-    it('should add response content disposition parameter', function(done) {
-      var disposition = 'attachment; filename="fname.ext"';
+    it('should add response-content-type parameter', function(done) {
+      var type = 'application/json';
       directoryFile.getSignedUrl({
         action: 'read',
         expires: Math.round(Date.now() / 1000) + 5,
-        responseDisposition: disposition
+        responseType: type
       }, function(err, signedUrl) {
-        assert(signedUrl.indexOf(encodeURIComponent(disposition)) > -1);
+        assert(signedUrl.indexOf(encodeURIComponent(type)) > -1);
         done();
       });
     });
 
-    it('should add response content type parameter', function(done) {
-      var type = 'application/json';
-      directoryFile.getSignedUrl({
-        action: 'read',
-        expires: Math.round(Date.now() / 1000) + 5,
-        responseType:  type
-      }, function(err, signedUrl) {
-        assert(signedUrl.indexOf(encodeURIComponent(type)) > -1);
-        done();
+    describe('promptSaveAs', function() {
+      it('should add response-content-disposition', function(done) {
+        var disposition = 'attachment; filename="fname.ext"';
+        directoryFile.getSignedUrl({
+          action: 'read',
+          expires: Math.round(Date.now() / 1000) + 5,
+          promptSaveAs: 'fname.ext'
+        }, function(err, signedUrl) {
+          assert(signedUrl.indexOf(disposition) > -1);
+          done();
+        });
+      });
+    });
+
+    describe('responseDisposition', function() {
+      it('should add response-content-disposition', function(done) {
+        var disposition = 'attachment; filename="fname.ext"';
+        directoryFile.getSignedUrl({
+          action: 'read',
+          expires: Math.round(Date.now() / 1000) + 5,
+          responseDisposition: disposition
+        }, function(err, signedUrl) {
+          assert(signedUrl.indexOf(encodeURIComponent(disposition)) > -1);
+          done();
+        });
+      });
+
+      it('should warn and ignore promptSaveAs if set', function(done) {
+        var disposition = 'attachment; filename="fname.ext"';
+        var saveAs = 'fname2.ext';
+        var oldWarn = console.warn;
+        console.warn = function(message) {
+          assert(message.indexOf('promptSaveAs') > -1);
+          console.warn = oldWarn;
+        };
+        directoryFile.getSignedUrl({
+          action: 'read',
+          expires: Math.round(Date.now() / 1000) + 5,
+          promptSaveAs: saveAs,
+          responseDisposition: 'attachment; filename="fname.ext"'
+        }, function(err, signedUrl) {
+          assert(signedUrl.indexOf(encodeURIComponent(disposition)) > -1);
+          assert(signedUrl.indexOf(encodeURIComponent(saveAs)) === -1);
+          done();
+        });
       });
     });