Improve pipeline to support bound local variables, locals in exec

Gemfile

@@ -4,5 +4,3 @@ git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
 
 # Specify your gem's dependencies in serbea.gemspec
 gemspec
-
-gem "erubi", github: "jaredcwhite/erubi", branch: "config-literal-prefix"

README.md

@@ -13,7 +13,7 @@ Serbea combines the best ideas from "brace-style" template languages such as Liq
 * Supports every convention of ERB and builds upon it with new features (which is why it's "awesomer!").
 * Builtin frontmatter support so you can access the variables written into the top YAML within your templates. In any Rails view, including layouts, you'll have access to the `@frontmatter` ivar which is a merged `HashWithDotAccess::Hash` with data from any part of the view tree (partials, pages, layout).
 * The filters accessible within Serbea templates are either helpers (where the variable gets passed as the first argument) or instance methods of the variable itself, so you can build extremely expressive pipelines that take advantage of the code you already know and love. (For example, in Rails you could write `{{ "My Link" | link_to: route_path }}`).
-* The `Serbea::Pipeline.exec` method lets you pass a pipeline template in, along with an optional input value or included helpers module, and you'll get the output as a object of any type (not converted to a string like in traditional templates). For example: `Serbea::Pipeline.exec("[1,2,3] |> map: ->(i) { i * 10 }")` will return `[10, 20, 30]`.
+* The `Serbea::Pipeline.exec` method lets you pass a pipeline template in, along with an optional input value or included helpers module, and you'll get the output as a object of any type (not converted to a string like in traditional templates). For example: `Serbea::Pipeline.exec("arr |> map: ->(i) { i * 10 }", arr: [1,2,3])` will return `[10, 20, 30]`.
 
 ## What It Looks Like
 

lib/serbea.rb

@@ -10,7 +10,7 @@ class SerbeaTemplate < ErubiTemplate
     def prepare
       @options.merge!(
         outvar: "@_erbout",
-        bufval: "Serbea::Buffer.new", 
+        bufval: "Serbea::OutputBuffer.new", 
         literal_prefix: "{%",
         literal_postfix: "%}",
         engine_class: Serbea::TemplateEngine

lib/serbea/helpers.rb

@@ -8,11 +8,12 @@ def self.included(mod)
 
     def capture(obj = nil, &block)
       previous_buffer_state = @_erbout
-      @_erbout = Serbea::Buffer.new
+      @_erbout = Serbea::OutputBuffer.new
 
       # For compatibility with ActionView, not used by Bridgetown normally
       previous_ob_state = @output_buffer
-      @output_buffer = Serbea::Buffer.new
+      @output_buffer = Serbea::OutputBuffer.new
+
 
       result = instance_exec(obj, &block)
       if @output_buffer != ""
@@ -32,11 +33,11 @@ def pipeline(context, value)
     def helper(name, &helper_block)
       self.class.define_method(name) do |*args, &block|
         previous_buffer_state = @_erbout
-        @_erbout = Serbea::Buffer.new
+        @_erbout = Serbea::OutputBuffer.new
 
         # For compatibility with ActionView, not used by Bridgetown normally
         previous_ob_state = @output_buffer
-        @output_buffer = Serbea::Buffer.new
+        @output_buffer = Serbea::OutputBuffer.new
 
         result = helper_block.call(*args, &block)
         if @output_buffer != ""

lib/serbea/pipeline.rb

@@ -1,25 +1,25 @@
 require "active_support/core_ext/string/output_safety"
+require "active_support/core_ext/object/blank"
 
 module Serbea
   class Pipeline
-    def self.exec(template, input: (no_input_passed = true; nil), include_helpers: nil)
+    def self.exec(template, locals = {}, include_helpers: nil, **kwargs)
       anon = Class.new do
         include Serbea::Helpers
 
-        attr_accessor :input, :output
+        attr_accessor :output
       end
 
       if include_helpers
         anon.include include_helpers
       end
 
       pipeline_obj = anon.new
-      pipeline_obj.input = input unless no_input_passed
 
       full_template = "{{ #{template} | assign_to: :output }}"
 
       tmpl = Tilt::SerbeaTemplate.new { full_template }
-      tmpl.render(pipeline_obj)
+      tmpl.render(pipeline_obj, locals.presence || kwargs)
 
       pipeline_obj.output
     end
@@ -54,8 +54,9 @@ def self.value_methods_denylist
       @value_methods_denylist ||= Set.new
     end
 
-    def initialize(context, value)
-      @context = context
+    def initialize(binding, value)
+      @binding = binding
+      @context = binding.receiver
       @value = value
     end
 
@@ -83,6 +84,19 @@ def filter(name, *args, **kwargs)
         else
           @value = @context.send(name, @value, *args)
         end
+      elsif @binding.local_variables.include?(name)
+        var = @binding.local_variable_get(name)
+        if var.respond_to?(:call)
+          unless kwargs.empty?
+            @value = var.call(@value, *args, **kwargs)
+          else
+            @value = var.call(@value, *args)
+          end
+        else
+          "Serbea warning: Filter #{name} does not respond to call".tap do |warning|
+            self.class.raise_on_missing_filters ? raise(warning) : STDERR.puts(warning)
+          end
+        end
       else
         "Serbea warning: Filter not found: #{name}".tap do |warning|
           self.class.raise_on_missing_filters ? raise(warning) : STDERR.puts(warning)

lib/serbea/template_engine.rb

@@ -1,7 +1,7 @@
 require "strscan"
 
 module Serbea
-  class Buffer < String
+  class OutputBuffer < String
     def concat_to_s(input)
       concat input.to_s
     end
@@ -125,7 +125,7 @@ def process_serbea_input(template, properties)
             end
           end
 
-          segments[0] = "pipeline(self, (#{segments[0].strip}))"
+          segments[0] = "pipeline(binding, (#{segments[0].strip}))"
           segments[1..-1].each_with_index do |segment, index|
             filter, args = segment.strip.match(/([^ :]*)(.*)/m).captures
             segments[index + 1] = ".filter(:" + filter

lib/version.rb

@@ -1,3 +1,3 @@
 module Serbea
-  VERSION = "0.8.1"
+  VERSION = "0.9.0"
 end

serbea.gemspec

@@ -17,7 +17,7 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_runtime_dependency("activesupport", "~> 6.0")
-  spec.add_runtime_dependency("erubi", "~> 1.9")
+  spec.add_runtime_dependency("erubi", ">= 1.10")
   spec.add_runtime_dependency("hash_with_dot_access", "~> 1.1")
   spec.add_runtime_dependency("tilt", "~> 2.0")
 

test/template.serb

@@ -148,3 +148,6 @@ Prepend permanent?
 {{ [1, 3, 6] \| [2, 3, 9] | join: "-" | append: " Foo \| bar!" | gsub: /ba\|r/, "x" }}
 
 {{ LambdaTest.new | scope: "lambda test", ->(x) { x * 20 }, ->{} | center: 50 }}
+
+{% use_local_helper = ->(input) { input.downcase } %}
+{{ "YO" | use_local_helper }}

test/test.rb

@@ -78,7 +78,7 @@ def page
 
   def form(classname:)
     previous_buffer_state = @_erbout
-    @_erbout = Serbea::Buffer.new
+    @_erbout = Serbea::OutputBuffer.new
     fields = Fields.new
     str = "<form class=\"#{classname}\">"
     str << yield(fields)

test/test_output.txt

@@ -93,3 +93,5 @@ ha1heha2heha3he
 1-3-6-2-9 Foo | xx!
 
           Name: lambda test, output: 200          
+
+yo