Allow symbol_matcher in symbol_matchers plugin to take a block to all…

…ow type conversion

This allows symbol matchers to have the same flexibility as class
matchers.

This changes the behavior of the automatically generated
match_symbol_* private request methods to return an array of the
regexp and any conversion block, instead of just the regexp.

CHANGELOG

@@ -1,3 +1,7 @@
+= master
+
+* Allow symbol_matcher in symbol_matchers plugin to take a block to allow type conversion (jeremyevans)
+
 = 3.68.0 (2023-05-11)
 
 * Make Roda.run in multi_run plugin accept blocks to allow autoloading the apps to dispatch to (jeremyevans)

lib/roda/plugins/symbol_matchers.rb

@@ -37,6 +37,35 @@ module RodaPlugins
     #
     # If using this plugin with the params_capturing plugin, this plugin should
     # be loaded first.
+    #
+    # You can provide a block when calling +symbol_matcher+, and it will be called
+    # for all matches to allow for type conversion.  The block must return an
+    # array:
+    #
+    #   symbol_matcher(:date, /(\d\d\d\d)-(\d\d)-(\d\d)/) do |y, m, d|
+    #     [Date.new(y.to_i, m.to_i, d.to_i)]
+    #   end
+    #
+    #   route do |r|
+    #     r.on :date do |date|
+    #       # date is an instance of Date
+    #     end
+    #   end
+    #
+    # If you have a segment match the passed regexp, but decide during block
+    # processing that you do not want to treat it as a match, you can have the
+    # block return nil or false.  This is useful if you want to make sure you
+    # are using valid data:
+    #
+    #   symbol_matcher(:date, /(\d\d\d\d)-(\d\d)-(\d\d)/) do |y, m, d|
+    #     y = y.to_i
+    #     m = m.to_i
+    #     d = d.to_i
+    #     [Date.new(y, m, d)] if Date.valid_date?(y, m, d)
+    #   end
+    #
+    # However, if providing a block to the symbol_matchers plugin, the symbol may 
+    # not work with the params_capturing plugin.
     module SymbolMatchers
       def self.load_dependencies(app)
         app.plugin :_symbol_regexp_matchers
@@ -50,9 +79,10 @@ def self.configure(app)
 
       module ClassMethods
         # Set the regexp to use for the given symbol, instead of the default.
-        def symbol_matcher(s, re)
+        def symbol_matcher(s, re, &block)
           meth = :"match_symbol_#{s}"
-          self::RodaRequest.send(:define_method, meth){re}
+          array = [re, block].freeze
+          self::RodaRequest.send(:define_method, meth){array}
           self::RodaRequest.send(:private, meth)
         end
       end
@@ -67,8 +97,8 @@ def _match_symbol(s)
           meth = :"match_symbol_#{s}"
           if respond_to?(meth, true)
             # Allow calling private match methods
-            re = send(meth)
-            consume(self.class.cached_matcher(re){re})
+            re, block = send(meth)
+            consume(self.class.cached_matcher(re){re}, &block)
           else
             super
           end
@@ -80,7 +110,8 @@ def _match_symbol_regexp(s)
           meth = :"match_symbol_#{s}"
           if respond_to?(meth, true)
             # Allow calling private match methods
-            send(meth)
+            re, = send(meth)
+            re
           else
             super
           end

spec/plugin/symbol_matchers_spec.rb

@@ -5,6 +5,9 @@
     app(:bare) do
       plugin :symbol_matchers
       symbol_matcher(:f, /(f+)/)
+      symbol_matcher(:c, /(c+)/) do |cs|
+        [cs, cs.length] unless cs.length == 5
+      end
 
       route do |r|
         r.is :d do |d|
@@ -19,6 +22,10 @@
           "f#{f}"
         end
 
+        r.is :c do |cs, nc|
+          "#{cs}#{nc}"
+        end
+
         r.is 'q', :rest do |rest|
           "rest#{rest}"
         end
@@ -27,8 +34,8 @@
           "w#{w}"
         end
 
-        r.is :d, :w, :f do |d, w, f|
-          "dwf#{d}#{w}#{f}"
+        r.is :d, :w, :f, :c do |d, w, f, cs, nc|
+          "dwfc#{d}#{w}#{f}#{cs}#{nc}"
         end
       end
     end
@@ -40,9 +47,12 @@
     body("/1az0").must_equal 'w1az0'
     body("/f").must_equal 'ff'
     body("/ffffffffffffffff").must_equal 'fffffffffffffffff'
+    body("/c").must_equal 'c1'
+    body("/cccc").must_equal 'cccc4'
+    body("/ccccc").must_equal 'wccccc'
     status("/-").must_equal 404
-    body("/1/1a/f").must_equal 'dwf11af'
-    body("/12/1azy/fffff").must_equal 'dwf121azyfffff'
+    body("/1/1a/f/cc").must_equal 'dwfc11afcc2'
+    body("/12/1azy/fffff/ccc").must_equal 'dwfc121azyfffffccc3'
     status("/1/f/a").must_equal 404
     body("/q/a/b/c/d//f/g").must_equal 'resta/b/c/d//f/g'
     body('/q/').must_equal 'rest'