PrettyWriter formatting options.

This change adds PrettyWriter::SetFormatOptions with a corresponding
bitfield enum PrettyFormatOptions. This allows options affecting the
format of the PrettyWriter to be set. The first option to be provided
is kFormatSingleLineArray, which instructs the PrettyWriter to write
arrays on a single line, rather than breaking them up onto a line
per element.

include/rapidjson/prettywriter.h

@@ -24,6 +24,14 @@ RAPIDJSON_DIAG_OFF(effc++)
 
 RAPIDJSON_NAMESPACE_BEGIN
 
+//! Combination of PrettyWriter format flags.
+/*! \see PrettyWriter::SetFormatOptions
+ */
+enum PrettyFormatOptions {
+    kFormatDefault = 0,         //!< Default pretty formatting.
+    kFormatSingleLineArray = 1  //!< Format arrays on a single line.
+};
+
 //! Writer with indentation and spacing.
 /*!
     \tparam OutputStream Type of ouptut os.
@@ -43,7 +51,7 @@ public:
         \param levelDepth Initial capacity of stack.
     */
     explicit PrettyWriter(OutputStream& os, StackAllocator* allocator = 0, size_t levelDepth = Base::kDefaultLevelDepth) : 
-        Base(os, allocator, levelDepth), indentChar_(' '), indentCharCount_(4) {}
+        Base(os, allocator, levelDepth), indentChar_(' '), indentCharCount_(4), formatOptions_(kFormatDefault) {}
 
 
     explicit PrettyWriter(StackAllocator* allocator = 0, size_t levelDepth = Base::kDefaultLevelDepth) : 
@@ -61,6 +69,14 @@ public:
         return *this;
     }
 
+    //! Set pretty writer formatting options.
+    /*! \param options Formatting options.
+    */
+    PrettyWriter& SetFormatOptions(PrettyFormatOptions options) {
+        formatOptions_ = options;
+        return *this;
+    }
+
     /*! @name Implementation of Handler
         \see Handler
     */
@@ -130,7 +146,7 @@ public:
         RAPIDJSON_ASSERT(Base::level_stack_.template Top<typename Base::Level>()->inArray);
         bool empty = Base::level_stack_.template Pop<typename Base::Level>(1)->valueCount == 0;
 
-        if (!empty) {
+        if (!empty && !(formatOptions_ & kFormatSingleLineArray)) {
             Base::os_->Put('\n');
             WriteIndent();
         }
@@ -173,11 +189,14 @@ protected:
             if (level->inArray) {
                 if (level->valueCount > 0) {
                     Base::os_->Put(','); // add comma if it is not the first element in array
-                    Base::os_->Put('\n');
+                    if (formatOptions_ & kFormatSingleLineArray)
+                        Base::os_->Put(' ');
                 }
-                else
+
+                if (!(formatOptions_ & kFormatSingleLineArray)) {
                     Base::os_->Put('\n');
-                WriteIndent();
+                    WriteIndent();
+                }
             }
             else {  // in object
                 if (level->valueCount > 0) {
@@ -213,6 +232,7 @@ protected:
 
     Ch indentChar_;
     unsigned indentCharCount_;
+    PrettyFormatOptions formatOptions_;
 
 private:
     // Prohibit copy constructor & assignment operator.

test/unittest/prettywritertest.cpp

@@ -39,6 +39,19 @@ static const char kPrettyJson[] =
 "    \"i64\": -1234567890123456789\n"
 "}";
 
+static const char kPrettyJson_FormatOptions_SLA[] =
+"{\n"
+"    \"hello\": \"world\",\n"
+"    \"t\": true,\n"
+"    \"f\": false,\n"
+"    \"n\": null,\n"
+"    \"i\": 123,\n"
+"    \"pi\": 3.1416,\n"
+"    \"a\": [1, 2, 3, -1],\n"
+"    \"u64\": 1234567890123456789,\n"
+"    \"i64\": -1234567890123456789\n"
+"}";
+
 TEST(PrettyWriter, Basic) {
     StringBuffer buffer;
     PrettyWriter<StringBuffer> writer(buffer);
@@ -48,6 +61,16 @@ TEST(PrettyWriter, Basic) {
     EXPECT_STREQ(kPrettyJson, buffer.GetString());
 }
 
+TEST(PrettyWriter, FormatOptions) {
+    StringBuffer buffer;
+    PrettyWriter<StringBuffer> writer(buffer);
+    writer.SetFormatOptions(kFormatSingleLineArray);
+    Reader reader;
+    StringStream s(kJson);
+    reader.Parse(s, writer);
+    EXPECT_STREQ(kPrettyJson_FormatOptions_SLA, buffer.GetString());
+}
+
 TEST(PrettyWriter, SetIndent) {
     StringBuffer buffer;
     PrettyWriter<StringBuffer> writer(buffer);