Extract JSON generating for preview to each RegexpPreview class

app/controllers/api_controller.rb

@@ -20,19 +20,8 @@ class ApiController < ApplicationController
 
   def regexp_preview
     preview = RegexpPreview.processor(params[:format]).new(params[:file], params[:format], params)
-    matches = preview.matches
 
-    render json: {
+    render json: preview.matches_json
-      params: {
-        setting: {
-          # NOTE: regexp and timeformat are used when format == 'apache' || 'nginx' || etc.
-          # TODO: prepare rendered JSON by prcessor(RegexpPreview::{Signle,Multi}Line
-          regexp: preview.try(:regexp).try(:source),
-          time_format: preview.try(:time_format),
-        }
-      },
-      matches: matches.compact,
-    }
   end
 
   def grok_to_regexp

lib/regexp_preview/multi_line.rb

@@ -8,6 +8,20 @@ module RegexpPreview
       @params = params[:params]
     end
 
+    def matches_json
+      {
+        params: {
+          setting: { # for vue.js
+            regexp: nil,
+            time_format: nil,
+          }
+        },
+        matches: matches.compact,
+      }
+    end
+
+    private
+
     def matches
       return [] if patterns.empty?
       reader = FileReverseReader.new(File.open(file))

lib/regexp_preview/single_line.rb

@@ -1,11 +1,13 @@
 module RegexpPreview
   class SingleLine
-    attr_reader :file, :format, :params, :regexp
+    attr_reader :file, :format, :params, :regexp, :time_format
 
     def initialize(file, format, params = {})
       @file = file
       @format = format
+      @time_format = params[:time_format]
       @params = params
+
       case format
       when "regexp"
         @regexp = Regexp.new(params[:regexp])
@@ -18,6 +20,21 @@ module RegexpPreview
       end
     end
 
+    def matches_json
+      {
+        params: {
+          setting: {
+            # NOTE: regexp and time_format are used when format == 'apache' || 'nginx' || etc.
+            regexp: regexp.source,
+            time_format: time_format,
+          }
+        },
+        matches: matches.compact,
+      }
+    end
+
+    private
+
     def matches
       return [] unless @regexp # such as ltsv, json, apache, etc
       reader = FileReverseReader.new(File.open(file))