Added YAML parser node (#1034)

Thanks @natcl -
(sorry pressed closed by mistake !)
* Added YAML parser node

* Added YAML error strings in messages.json

* Change location of YAML library import

* Remove copyright

* Remove copyright

* Change order of yaml in Template node

* Add YAML test

* Add working test

nodes/core/core/80-template.html

@@ -37,6 +37,7 @@
                 <option value="css">CSS</option>
                 <option value="markdown">Markdown</option>
                 <option value="text">none</option>
+                <option value="yaml">YAML</option>
             </select>
         </div>
     </div>

nodes/core/locales/en-US/messages.json

@@ -614,6 +614,13 @@
             "dropped-error": "Failed to convert payload"
         }
     },
+    "yaml": {
+        "errors": {
+            "dropped-object": "Ignored non-object payload",
+            "dropped": "Ignored unsupported payload type",
+            "dropped-error": "Failed to convert payload"
+        }
+    },
     "xml": {
         "label": {
             "represent": "Represent XML tag attributes as a property named",

nodes/core/parsers/70-YAML.html

@@ -0,0 +1,31 @@
+<script type="text/x-red" data-template-name="yaml">
+    <div class="form-row">
+        <label for="node-input-name"><i class="fa fa-tag"></i> <span data-i18n="common.label.name"></span></label>
+        <input type="text" id="node-input-name" data-i18n="[placeholder]common.label.name">
+    </div>
+</script>
+
+<script type="text/x-red" data-help-name="yaml">
+    <p>A function that parses the <code>msg.payload</code> to convert a YAML string to/from a javascript object. Places the result back into the payload.</p>
+    <p>If the input is a YAML string it tries to parse it to a javascript object.</p>
+    <p>If the input is a javascript object it creates a YAML string.</p>
+</script>
+
+<script type="text/javascript">
+    RED.nodes.registerType('yaml',{
+        category: 'function',
+        color:"#DEBD5C",
+        defaults: {
+            name: {value:""}
+        },
+        inputs:1,
+        outputs:1,
+        icon: "parser-yaml.png",
+        label: function() {
+            return this.name||"yaml";
+        },
+        labelStyle: function() {
+            return this.name?"node_label_italic":"";
+        }
+    });
+</script>

nodes/core/parsers/70-YAML.js

@@ -0,0 +1,34 @@
+module.exports = function(RED) {
+    "use strict";
+    var yaml = require('js-yaml');
+    function YAMLNode(n) {
+        RED.nodes.createNode(this,n);
+        var node = this;
+        this.on("input", function(msg) {
+            if (msg.hasOwnProperty("payload")) {
+                if (typeof msg.payload === "string") {
+                    try {
+                        msg.payload = yaml.load(msg.payload);
+                        node.send(msg);
+                    }
+                    catch(e) { node.error(e.message,msg); }
+                }
+                else if (typeof msg.payload === "object") {
+                    if (!Buffer.isBuffer(msg.payload)) {
+                        try {
+                            msg.payload = yaml.dump(msg.payload);
+                            node.send(msg);
+                        }
+                        catch(e) {
+                            node.error(RED._("yaml.errors.dropped-error"));
+                        }
+                    }
+                    else { node.warn(RED._("yaml.errors.dropped-object")); }
+                }
+                else { node.warn(RED._("yaml.errors.dropped")); }
+            }
+            else { node.send(msg); } // If no payload - just pass it on.
+        });
+    }
+    RED.nodes.registerType("yaml",YAMLNode);
+};