Tag select with optgroups option in combination with value option

[v-kolesnikov]

Hi!

I came across an ambiguous behaviour of select tag with optgroups option in combination with value option.

Consider the following tag:

 <select>
   A <-- optgroup
     Cat
     Dog <<- Selected if the current value of object field is `Dog`
   B <-- optgroup
     Cow <<- Should be selected if the current value of object field is `Cow` but isn't
 </select>

optgroups = [['A',
              [['Cat', :cat],
               ['Dog', :dog]]],
             ['B',
              [['Cow', :cow]]]]

# 1. With object
data = { item: :dog }
f = Forme::Form.new(obj: data)
f.input :item, type: :select, optgroups: optgroups
# =>
# <select id="item" name="item">
#   <optgroup label="A">
#     <option value="cat">Cat</option>
#     <option selected="selected" value="dog">Dog</option>
#   </optgroup>
#   <optgroup label="B">
#     <option value="cow">Cow</option>
#   </optgroup>
# </select>

data = { item: :cow }
f = Forme::Form.new(obj: data)
f.input :item, type: :select, optgroups: optgroups
# =>
# <select id="item" name="item">
#    <optgroup label="A">
#       <option value="cat">Cat</option>
#       <option value="dog">Dog</option>
#    </optgroup>
#    <optgroup label="B">
#       <option value="cow">Cow</option>
#    </optgroup>
# </select>

# 2. Works when `selected` is specified.
f = Forme::Form.new
f.input :select, optgroups: optgroups, selected: :dog
# => <select><optgroup label="A"><option value="cat">Cat</option><option selected="selected" value="dog">Dog</option></optgroup><optgroup label="B"><option value="cow">Cow</option></optgroup></select>
f.input :select, optgroups: optgroups, selected: :cow
# => <select><optgroup label="A"><option value="cat">Cat</option><option value="dog">Dog</option></optgroup><optgroup label="B"><option selected="selected" value="cow">Cow</option></optgroup></select>

# 3. Doesn't work when `value` is specified
f = Forme::Form.new
f.input :select, optgroups: optgroups, value: :dog
# => <select><optgroup label="A"><option value="cat">Cat</option><option selected="selected" value="dog">Dog</option></optgroup><optgroup label="B"><option value="cow">Cow</option></optgroup></select>
f.input :select, optgroups: optgroups, value: :cow
# => <select><optgroup label="A"><option value="cat">Cat</option><option value="dog">Dog</option></optgroup><optgroup label="B"><option value="cow">Cow</option></optgroup></select>

I've also found a reason for that in Formatter:

forme/lib/forme/transformers/formatter.rb

Lines 411 to 415 in b480ce4

	def process_select_optgroups(grouper, &block)
	os = if groups = @opts[:optgroups]
	groups.map do |group, options|
	send(grouper, group, process_select_options(options, &block))
	end

forme/lib/forme/transformers/formatter.rb

Lines 434 to 437 in b480ce4

	def process_select_options(os)
	vm = @opts[:value_method]
	tm = @opts[:text_method]
	sel = @opts[:selected] || @attr.delete(:value)

forme/lib/forme/transformers/formatter.rb

Line 437 in b480ce4

sel = @opts[:selected] || @attr.delete(:value)

On iteration over optgroups field value of @attr var deleted on the first group iteration.

I'm ready to send a PR if needed.

# lib/forme/transformers/formatter.rb

    def process_select_optgroups(grouper, &block)
      os = if groups = @opts[:optgroups]
        groups.map do |group, options|
          send(grouper, group, process_select_options(options, &block))
        end
      else
        return unless @opts[:options]
        process_select_options(@opts[:options], &block)
      end
      @attr.delete(:value) # `value` should be deleted to keep compatibility in tests
      ...
    end

    def process_select_options(os)
      vm = @opts[:value_method]
      tm = @opts[:text_method]
      sel = @opts[:selected] || @attr[:value]
      ...
    end

# spec/forme_spec.rb

  it "should create select tag with option groups and specified value" do
    @f.input(:select, :optgroups=>[['d', [[:a, 1], [:b, 2]]], ['e', [[:c, 3]]]], :value=>3).must_equal '<select><optgroup label="d"><option value="1">a</option><option value="2">b</option></optgroup><optgroup label="e"><option selected="selected" value="3">c</option></optgroup></select>'
  end

[v-kolesnikov]

From bf16dcf52ad2148de4055c52105394ac3569a7cf Mon Sep 17 00:00:00 2001
From: Vasily Kolesnikov <re.vkolesnikov@gmail.com>
Date: Fri, 27 Jan 2023 04:25:39 +0300
Subject: [PATCH] Fix tag select with optgroups and value opts

---
 lib/forme/transformers/formatter.rb | 3 ++-
 spec/forme_spec.rb                  | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/forme/transformers/formatter.rb b/lib/forme/transformers/formatter.rb
index 8847265..c9dc32a 100644
--- a/lib/forme/transformers/formatter.rb
+++ b/lib/forme/transformers/formatter.rb
@@ -417,6 +417,7 @@ module Forme
         return unless @opts[:options]
         process_select_options(@opts[:options], &block)
       end
+      @attr.delete(:value)
 
       if prompt = @opts[:add_blank]
         unless prompt.is_a?(String)
@@ -434,7 +435,7 @@ module Forme
     def process_select_options(os)
       vm = @opts[:value_method]
       tm = @opts[:text_method]
-      sel = @opts[:selected] || @attr.delete(:value)
+      sel = @opts[:selected] || @attr[:value]
 
       if @opts[:multiple]
         sel = Array(sel)
diff --git a/spec/forme_spec.rb b/spec/forme_spec.rb
index e52858f..bdc8667 100644
--- a/spec/forme_spec.rb
+++ b/spec/forme_spec.rb
@@ -378,6 +378,10 @@ describe "Forme plain forms" do
     @f.input(:select, :optgroups=>[['d', [[:a, 1], [:b, 2]]], ['e', [[:c, 3]]]], :selected=>2).must_equal '<select><optgroup label="d"><option value="1">a</option><option selected="selected" value="2">b</option></optgroup><optgroup label="e"><option value="3">c</option></optgroup></select>'
   end
 
+  it "should create select tag with option groups and specified value" do
+    @f.input(:select, :optgroups=>[['d', [[:a, 1], [:b, 2]]], ['e', [[:c, 3]]]], :value=>3).must_equal '<select><optgroup label="d"><option value="1">a</option><option value="2">b</option></optgroup><optgroup label="e"><option selected="selected" value="3">c</option></optgroup></select>'
+  end
+
   it "should create select tag with option groups with attributes" do
     @f.input(:select, :optgroups=>[[{:label=>'d', :class=>'f'}, [[:a, 1], [:b, 2]]], [{:label=>'e', :class=>'g'}, [[:c, 3]]]], :selected=>2).must_equal '<select><optgroup class="f" label="d"><option value="1">a</option><option selected="selected" value="2">b</option></optgroup><optgroup class="g" label="e"><option value="3">c</option></optgroup></select>'
   end
-- 
2.38.1

[jeremyevans]

Great work on this! I can apply your patch, but if you want to submit it as a PR, I can merge that directly.

[v-kolesnikov]

Great work on this! I can apply your patch, but if you want to submit it as a PR, I can merge that directly.

Done! #111