Merge pull request #3009 from crystal-lang/feature/to_pretty_json_indent

to_pretty_json: allow custom indent string. Fixes #2979
crystal-lang · Jul 18, 2016 · db7c8f8 · db7c8f8
2 parents 277609e + 6ad39f3
commit db7c8f8
Showing 2 changed files with 29 additions and 21 deletions.
diff --git a/spec/std/json/serialization_spec.cr b/spec/std/json/serialization_spec.cr
@@ -262,6 +262,14 @@ describe "JSON serialization" do
     it "does for empty Hash" do
       ({} of Nil => Nil).to_pretty_json.should eq(%({}))
     end
+
+    it "does for Array with indent" do
+      [1, 2, 3].to_pretty_json(indent: " ").should eq("[\n 1,\n 2,\n 3\n]")
+    end
+
+    it "does for nested Hash with indent" do
+      {"foo" => {"bar" => 1}}.to_pretty_json(indent: " ").should eq(%({\n "foo": {\n  "bar": 1\n }\n}))
+    end
   end
 
   it "generates an array with JSON::Builder" do

diff --git a/src/json/to_json.cr b/src/json/to_json.cr
@@ -5,20 +5,20 @@ class Object
     end
   end
 
-  def to_pretty_json
+  def to_pretty_json(indent : String = "  ")
     String.build do |str|
-      to_pretty_json str
+      to_pretty_json str, indent: indent
     end
   end
 
-  def to_pretty_json(io : IO)
-    to_json JSON::PrettyWriter.new(io)
+  def to_pretty_json(io : IO, indent : String = "  ")
+    to_json JSON::PrettyWriter.new(io, indent: indent)
   end
 end
 
 # Handly struct to write JSON objects
 struct JSON::ObjectBuilder(T)
-  def initialize(@io : T, @indent = 0)
+  def initialize(@io : T, @indent : String = "  ", @indent_level : Int32 = 0)
     @count = 0
   end
 
@@ -32,20 +32,20 @@ struct JSON::ObjectBuilder(T)
   def field(name)
     if @count > 0
       @io << ","
-      @io << '\n' if @indent > 0
+      @io << '\n' if @indent_level > 0
     end
-    @indent.times { @io << "  " }
+    @indent_level.times { @io << @indent }
     name.to_s.to_json(@io)
     @io << ":"
-    @io << " " if @indent > 0
+    @io << " " if @indent_level > 0
     yield
     @count += 1
   end
 end
 
 # Handly struct to write JSON arrays
 struct JSON::ArrayBuilder(T)
-  def initialize(@io : T, @indent = 0)
+  def initialize(@io : T, @indent : String = "  ", @indent_level : Int32 = 0)
     @count = 0
   end
 
@@ -64,9 +64,9 @@ struct JSON::ArrayBuilder(T)
   def push
     if @count > 0
       @io << ","
-      @io << '\n' if @indent > 0
+      @io << '\n' if @indent_level > 0
     end
-    @indent.times { @io << "  " }
+    @indent_level.times { @io << @indent }
     yield
     @count += 1
   end
@@ -116,30 +116,30 @@ end
 class JSON::PrettyWriter
   include IO
 
-  def initialize(@io : IO)
-    @indent = 0
+  def initialize(@io : IO, @indent : String)
+    @indent_level = 0
   end
 
   delegate read, to: @io
   delegate write, to: @io
 
   def json_object
     self << "{\n"
-    @indent += 1
-    yield JSON::ObjectBuilder.new(self, @indent)
-    @indent -= 1
+    @indent_level += 1
+    yield JSON::ObjectBuilder.new(self, @indent, @indent_level)
+    @indent_level -= 1
     self << '\n'
-    @indent.times { @io << "  " }
+    @indent_level.times { @io << @indent }
     self << "}"
   end
 
   def json_array
     self << "[\n"
-    @indent += 1
-    yield JSON::ArrayBuilder.new(self, @indent)
-    @indent -= 1
+    @indent_level += 1
+    yield JSON::ArrayBuilder.new(self, @indent, @indent_level)
+    @indent_level -= 1
     self << '\n'
-    @indent.times { @io << "  " }
+    @indent_level.times { @io << @indent }
     self << ']'
   end
 end