Allow array values for the label_col and control_col options.

Fixes #703

Author: UweKubosch

.gitignore

@@ -3,8 +3,7 @@
 log/*.log
 pkg/
 demo/db/*.sqlite3
-demo/doc/screenshots/**/*.committed.png
-demo/doc/screenshots/**/*.latest.png
+demo/doc/screenshots/**/*.diff.png
 demo/log/*.log
 demo/tmp/
 *.gem

README.md

@@ -1214,7 +1214,7 @@ The `label_col` and `control_col` css classes can also be changed per control:
 ```erb
 <%= bootstrap_form_for(@user, layout: :horizontal) do |f| %>
   <%= f.email_field :email %>
-  <%= f.text_field :age, label_col: "col-sm-3", control_col: "col-sm-3" %>
+  <%= f.text_field :age, label_col: %w[col-sm-3 text-bg-info], control_col: %w[col-sm-3 text-bg-success] %>
   <%= f.check_box :terms, label_col: "", control_col: "col-sm-11" %>
   <%= f.form_group do %>
     <%= f.submit %>
@@ -1233,8 +1233,8 @@ This generates:
     </div>
   </div>
   <div class="mb-3 row">
-    <label class="col-form-label col-sm-3" for="user_age">Age</label>
-    <div class="col-sm-3">
+    <label class="col-form-label col-sm-3 text-bg-info" for="user_age">Age</label>
+    <div class="col-sm-3 text-bg-success">
       <input class="form-control" id="user_age" name="user[age]" type="text" value="42">
     </div>
   </div>

demo/doc/screenshots/bootstrap/readme/41_example.png

@@ -104,7 +104,7 @@ def default_label_col
     end
 
     def offset_col(label_col)
-      label_col.gsub(/\bcol-(\w+)-(\d)\b/, 'offset-\1-\2')
+      [*label_col].flat_map { |s| s.split(/\s+/) }.grep(/^col-/).join(" ").gsub(/\bcol-(\w+)-(\d)\b/, 'offset-\1-\2')
     end
 
     def default_control_col

lib/bootstrap_form/form_builder.rb

@@ -686,7 +686,7 @@ def warn(message, ...)
       </form>
     HTML
     assert_equivalent_html expected,
-                           bootstrap_form_for(@user, layout: :horizontal, label_col: "col-sm-4 col-md-2",
+                           bootstrap_form_for(@user, layout: :horizontal, label_col: %w[col-sm-4 col-md-2],
                                                      control_col: "col-sm-8 col-md-10") { |f| f.form_group { f.submit } }
   end