Add examples on how to install a library from a spec repo, upstream repo,…

Add examples on how to install a library from a spec repo, upstream repo, :podspec, and inline spec.

examples/SSCatalog/Podfile

 platform :ios
 
-dependency 'SSToolkit'
 dependency 'AFNetworking'
+
+# From a spec repo
+#dependency 'SSToolkit'
+
+# Directly from the Pod’s repo
+#dependency 'SSToolkit', :git => 'https://github.com/samsoffes/sstoolkit.git'
+
+# Directly from the Pod’s repo with a specific commit (or tag)
+#dependency 'SSToolkit', :git    => 'https://github.com/samsoffes/sstoolkit.git',
+#                        :commit => '2adcd0f81740d6b0cd4589af98790eee3bd1ae7b'
+
+# From a podspec that's outside a spec repo and the library’s repo
+#dependency 'SSToolkit', :podspec => 'https://raw.github.com/gist/1353347/ef1800da9c5f5d267a642b8d3950b41174f2a6d7/SSToolkit-0.1.1.podspec'
+
+# If no podspec is available anywhere, you can define one right in your Podfile
+dependency do |s|
+  s.name         = 'SSToolkit'
+  s.version      = '0.1.3'
+  s.platform     = :ios
+  s.source       = { :git => 'https://github.com/samsoffes/sstoolkit.git', :commit => '2adcd0f81740d6b0cd4589af98790eee3bd1ae7b' }
+  s.resources    = 'Resources'
+  s.source_files = 'SSToolkit/**/*.{h,m}'
+  s.frameworks   = 'QuartzCore', 'CoreGraphics'
+
+  def s.post_install(target)
+    prefix_header = config.project_pods_root + target.prefix_header_filename
+    prefix_header.open('a') do |file|
+      file.puts(%{#ifdef __OBJC__\n#import "SSToolkitDefines.h"\n#endif})
+    end
+  end
+end

lib/cocoapods/dependency.rb

@@ -41,17 +41,21 @@ module Pod
     def specification
       @specification ||= begin
         if @external_spec_source
-          pod_root = Config.instance.project_pods_root + @name
+          config   = Config.instance
+          pod_root = config.project_pods_root + @name
           spec     = nil
           if @external_spec_source[:podspec]
-            Config.instance.project_pods_root.mkdir
-            spec = Config.instance.project_pods_root + "#{@name}.podspec"
+            config.project_pods_root.mkpath
+            spec = config.project_pods_root + "#{@name}.podspec"
+            source = @external_spec_source[:podspec]
             # can be http, file, etc
             require 'open-uri'
-            open(@external_spec_source[:podspec]) do |io|
+            puts "  * Fetching podspec for `#{@name}' from: #{source}" unless config.silent?
+            open(source) do |io|
               spec.open('w') { |f| f << io.read }
             end
           else
+            puts "  * Pre-downloading: `#{@name}'" unless config.silent?
             Downloader.for_source(pod_root, @external_spec_source).download
             spec = pod_root + "#{@name}.podspec"
           end

lib/cocoapods/specification.rb

@@ -10,6 +10,9 @@ module Pod
 
     # The file is expected to define and return a Pods::Specification.
     def self.from_file(path)
+      unless path.exist?
+        raise Informative, "No podspec exists at path `#{path}'."
+      end
       spec = Pod._eval_podspec(path)
       spec.defined_in_file = path
       spec