Merge pull request #76 from rhuss/master

Add new feature LITERAL_BLOCK_STYLE

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/dataformat/yaml/YAMLGenerator.java

@@ -91,7 +91,16 @@ public enum Feature // implements FormatFeature // for 2.7
          *
          * @since 2.8.2
          */
-        ALWAYS_QUOTE_NUMBERS_AS_STRINGS(false)
+        ALWAYS_QUOTE_NUMBERS_AS_STRINGS(false),
+
+        /**
+         * Whether for string containing newlines a <a href="http://www.yaml.org/spec/1.2/spec.html#style/block/literal">literal block style</a>
+         * should be used. This automatically enabled when {@link #MINIMIZE_QUOTES} is set.
+         * <p>
+         * The content of such strings is limited to printable characters according to the rules of
+         * <a href="http://www.yaml.org/spec/1.2/spec.html#style/block/literal">literal block style</a>.
+         */
+        LITERAL_BLOCK_STYLE(false)
         ;
 
         protected final boolean _defaultState;
@@ -488,6 +497,8 @@ public void writeString(String text) throws IOException,JsonGenerationException
             } else {
                 style = STYLE_PLAIN;
             }
+        } else if (Feature.LITERAL_BLOCK_STYLE.enabledIn(_formatFeatures) && text.indexOf('\n') >= 0) {
+            style = STYLE_LITERAL;
         }
         _writeScalar(text, "string", style);
     }

src/test/java/com/fasterxml/jackson/dataformat/yaml/SimpleGenerationTest.java

@@ -332,6 +332,31 @@ public void testNonQuoteNumberStoredAsString() throws Exception
                 "key: 2.0.1.2.3", yaml);
     }
 
+    public void testLiteralBlockStyle() throws Exception
+    {
+        YAMLFactory f = new YAMLFactory();
+        // verify default settings
+        assertFalse(f.isEnabled(YAMLGenerator.Feature.LITERAL_BLOCK_STYLE));
+
+        f.configure(YAMLGenerator.Feature.LITERAL_BLOCK_STYLE, true);
+
+        YAMLMapper mapper = new YAMLMapper(f);
+
+        Map<String, Object> content = new HashMap<String, Object>();
+        content.put("text", "Hello\nWorld");
+        String yaml = mapper.writeValueAsString(content).trim();
+
+        assertEquals("---\n" +
+                     "text: |-\n  Hello\n  World", yaml);
+
+        content.clear();
+        content.put("text", "Hello World");
+        yaml = mapper.writeValueAsString(content).trim();
+
+        assertEquals("---\n" +
+                     "text: \"Hello World\"", yaml);
+    }
+
     /*
     /**********************************************************************
     /* Helper methods