Merge branch 'Oldharlem-master'

Author: jassa

README.md

@@ -18,18 +18,32 @@ See [example](http://backbonejs.org/#examples) (scroll down to see images load)
 ### Features
 
 * Add `lazy: true` option to Rails `image_tag` helpers to render lazyload-friendly img tags.
+* Global config available to make them lazy by default.
 * Simple (really). That's pretty much it.
 
 ### Example
 
 ```erb
-<%= image_tag "kittenz.png", alt: "OMG a cat!", lazy: true %>
+<%= image_tag "kittenz.png", lazy: true %>
+```
+
+or
+
+```ruby
+# config/initializers/lazyload.rb
+Lazyload::Rails.configure do |config|
+  config.lazy_by_default = true
+end
+```
+```erb
+<%= image_tag "kittenz.png" %>
 ```
 
 Equals:
 
 ```html
-<img alt="OMG a cat!" data-original="/images/kittenz.png" src="http://www.appelsiini.net/projects/lazyload/img/grey.gif">
+<img src="data:image/gif;base64,R0lGODdhAQABAPAAAMPDwwAAACwAAAAAAQABAAACAkQBADs="
+     data-original="/images/kittenz.png" />
 ```
 
 **PRO TIP!** You must set image dimensions either as width and height attributes or in CSS. Otherwise plugin might not work properly.
@@ -57,12 +71,16 @@ Lazy Load can be customized, [see more options](http://www.appelsiini.net/projec
 
 ## Configuration
 
-By default, a 1x1 grey gif is used as placeholder (from [http://appelsiini.net/projects/lazyload/img/grey.gif](http://www.appelsiini.net/projects/lazyload/img/grey.gif)). This can be easily customized:
-
 ```ruby
 # config/initializers/lazyload.rb
 Lazyload::Rails.configure do |config|
+  # By default, a 1x1 grey gif is used as placeholder ("data:image/gif;base64,...").
+  # This can be easily customized:
   config.placeholder = "/public/img/grey.gif"
+
+  # image_tag can return lazyload-friendly images by default,
+  # no need to pass the { lazy: true } option
+  config.lazy_by_default = true
 end
 ```
 

lib/lazyload-rails.rb

@@ -37,16 +37,18 @@ def image_tag(*attrs)
     options, args = extract_options_and_args(*attrs)
     image_html = rails_image_tag(*args)
 
-    if options[:lazy]
-      to_lazy_image(image_html)
+    is_lazy = options.fetch(:lazy) { Lazyload::Rails.configuration.lazy_by_default }
+
+    if is_lazy
+      to_lazy(image_html)
     else
       image_html
     end
   end
 
   private
 
-  def to_lazy_image(image_html)
+  def to_lazy(image_html)
     img = Nokogiri::HTML::DocumentFragment.parse(image_html).at_css("img")
 
     img["data-original"] = img["src"]

lib/lazyload-rails/config.rb

@@ -20,9 +20,18 @@ def placeholder=(new_placeholder)
         @placeholder = new_placeholder
       end
 
+      # When set to true every image_tag will include { lazy: true } by default
+      def lazy_by_default=(lazy_by_default)
+        @lazy_by_default = !!lazy_by_default
+      end
+      def lazy_by_default
+        @lazy_by_default
+      end
+
       # Set default settings
       def initialize
         @placeholder = "data:image/gif;base64,R0lGODdhAQABAPAAAMPDwwAAACwAAAAAAQABAAACAkQBADs="
+        @lazy_by_default = false
       end
     end
   end

test/test_image_tag.rb

@@ -5,6 +5,7 @@ class TestImageTag < ::ActionView::TestCase
 
   def setup
     backwards_compatibility_setup
+    Lazyload::Rails.reset
   end
 
   def test_lazy_option_sets_lazy_attributes
@@ -15,6 +16,29 @@ def test_lazy_option_sets_lazy_attributes
     assert_equal "101", img["width"]
   end
 
+  def test_lazy_by_default_config_sets_lazy_attributes
+    Lazyload::Rails.configure do |config|
+      config.lazy_by_default = true
+    end
+
+    img = parse(image_tag("foo.png", size: "101x151"))
+
+    assert_match %r(^.*foo.png$), img["data-original"]
+    assert_equal "151", img["height"]
+    assert_equal "101", img["width"]
+  end
+
+  def test_lazy_option_overrides_default_config
+    Lazyload::Rails.configure do |config|
+      config.lazy_by_default = true
+    end
+
+    img = parse(image_tag("foo.png", size: "101x151", lazy: false))
+
+    assert_nil img["data-original"]
+    assert_match %r(^.*foo.png$), img["src"]
+  end
+
   def test_lazy_attrs_override_conflicting_attributes
     conflicting_opts = { data: { original: "foo.png" } } # because the gem sets data-original
 
@@ -32,8 +56,6 @@ def test_custom_placeholder_is_used_instead_of_normal_src
 
     assert_equal "/public/img/grey.gif", img["src"]
     assert_match %r(^.*baz.png$), img["data-original"]
-
-    Lazyload::Rails.reset
   end
 
   def test_nonlazy_attributes_can_be_set