A little improvement

1. Replace params key 'q' with 'extended_sha1'. A extended SHA1 syntax is explained in 'man gitrevisions'.
2. Change the placeholder of looking for commit.
3. Change the label of ref filter.

app/views/projects/network/_head.html.haml

@@ -4,7 +4,7 @@
   .pull-left
     = form_tag project_network_path(@project, @id), method: :get do |f|
       .control-group
-        = label_tag :filter_ref, "Show only selected ref", class: 'control-label light'
+        = label_tag :filter_ref, "Begin with the selected commit", class: 'control-label light'
         .controls
           = check_box_tag :filter_ref, 1, @options[:filter_ref]
     - @options.each do |key, value|
@@ -15,9 +15,9 @@
       .control-group
         = label_tag :search , "Looking for commit:", class: 'control-label light'
         .controls
-          = text_field_tag :q, @options[:q], placeholder: "Input SHA", class: "search-input input-xlarge"
+          = text_field_tag :extended_sha1, @options[:extended_sha1], placeholder: "Input an extended SHA1 syntax", class: "search-input input-xlarge"
           = button_tag type: 'submit', class: 'btn vtop' do
             %i.icon-search
           - @options.each do |key, value|
-            = hidden_field_tag(key, value, id: nil) unless key == "q"
+            = hidden_field_tag(key, value, id: nil) unless key == "extended_sha1"

features/steps/project/project_network_graph.rb

@@ -76,7 +76,7 @@ class ProjectNetworkGraph < Spinach::FeatureSteps
   When 'I looking for a commit by SHA of "v2.1.0"' do
     within ".content .search" do
-      fill_in 'q', with: '98d6492'
+      fill_in 'extended_sha1', with: '98d6492'
       find('button').click
     end
     sleep 2
@@ -90,7 +90,7 @@ class ProjectNetworkGraph < Spinach::FeatureSteps
   When 'I look for a commit by ";"' do
     within ".content .search" do
-      fill_in 'q', with: ';'
+      fill_in 'extended_sha1', with: ';'
       find('button').click
     end
   end

lib/extracts_path.rb

@@ -95,17 +95,17 @@ module ExtractsPath
   # resolved (e.g., when a user inserts an invalid path or ref).
   def assign_ref_vars
     # assign allowed options
-    allowed_options = ["filter_ref", "q"]
+    allowed_options = ["filter_ref", "extended_sha1"]
     @options = params.select {|key, value| allowed_options.include?(key) && !value.blank? }
     @options = HashWithIndifferentAccess.new(@options)
     @id = get_id
     @ref, @path = extract_ref(@id)
     @repo = @project.repository
-    if @options[:q].blank?
+    if @options[:extended_sha1].blank?
       @commit = @repo.commit(@ref)
     else
-      @commit = @repo.commit(@options[:q])
+      @commit = @repo.commit(@options[:extended_sha1])
     end
     @tree = Tree.new(@repo, @commit.id, @ref, @path)
     @hex_path = Digest::SHA1.hexdigest(@path)