add support of persistable context to template node

nodes/core/core/80-template.html

@@ -77,7 +77,7 @@
 }</pre>
     <p>The resulting property will be:
     <pre>Hello Fred. Today is Monday</pre>
-    <p>It is possible to use a property from the flow context or global context. Just use <code>{{flow.name}}</code> or <code>{{global.name}}</code>.
+    <p>It is possible to use a property from the flow context or global context. Just use <code>{{flow.name}}</code> or <code>{{global.name}}</code>, or for persistable store <code>store</code> use <code>{{flow[store].name}}</code> or <code>{{flobal[store].name}}</code>.
     <p><b>Note: </b>By default, <i>mustache</i> will escape any HTML entities in the values it substitutes.
        To prevent this, use <code>{{{triple}}}</code> braces.
 </script>

nodes/core/core/80-template.js

@@ -19,20 +19,39 @@ module.exports = function(RED) {
     var mustache = require("mustache");
     var yaml = require("js-yaml");
 
+    function parseContext(key) {
+        var match = /^(flow|global)(\[(\w+)\])?\.(.+)/.exec(key);
+        if (match) {
+            var parts = {};
+            parts.type = match[1];
+            parts.store = (match[3] === '') ? "default" : match[3];
+            parts.field = match[4];
+            return parts;
+        }
+        return undefined;
+    }
 
     /**
-     * Custom Mustache Context capable to resolve message property and node
+     * Custom Mustache Context capable to collect message property and node
      * flow and global context
      */
-    function NodeContext(msg, nodeContext, parent, escapeStrings) {
+
+    function NodeContext(msg, nodeContext, parent, escapeStrings, promises, results) {
         this.msgContext = new mustache.Context(msg,parent);
         this.nodeContext = nodeContext;
         this.escapeStrings = escapeStrings;
+        this.promises = promises;
+        this.results = results;
     }
 
     NodeContext.prototype = new mustache.Context();
 
     NodeContext.prototype.lookup = function (name) {
+        var results = this.results;
+        if (results) {
+            var val = results.shift();
+            return val;
+        }
         // try message first:
         try {
             var value = this.msgContext.lookup(name);
@@ -45,23 +64,40 @@ module.exports = function(RED) {
                     value = value.replace(/\f/g, "\\f");
                     value = value.replace(/[\b]/g, "\\b");
                 }
+                this.promises.push(Promise.resolve(value));
                 return value;
             }
 
-            // try node context:
-            var dot = name.indexOf(".");
-            /* istanbul ignore else  */
-            if (dot > 0) {
-                var contextName = name.substr(0, dot);
-                var variableName = name.substr(dot + 1);
-
-                if (contextName === "flow" && this.nodeContext.flow) {
-                    return this.nodeContext.flow.get(variableName);
+            // try flow/global context:
+            var context = parseContext(name);
+            if (context) {
+                var type = context.type;
+                var store = context.store;
+                var field = context.field;
+                var target = this.nodeContext[type];
+                if (target) {
+                    var promise = new Promise((resolve, reject) => {
+                        var callback = (err, val) => {
+                            if (err) {
+                                reject(err);
+                            } else {
+                                resolve(val);
+                            }
+                        };
+                        target.get(field, store, callback);
+                    });
+                    this.promises.push(promise);
+                    return '';
                 }
-                else if (contextName === "global" && this.nodeContext.global) {
-                    return this.nodeContext.global.get(variableName);
+                else {
+                    this.promises.push(Promise.resolve(''));
+                    return '';
                 }
             }
+            else {
+                this.promises.push(Promise.resolve(''));
+                return '';
+            }
         }
         catch(err) {
             throw err;
@@ -69,7 +105,7 @@ module.exports = function(RED) {
     }
 
     NodeContext.prototype.push = function push (view) {
-        return new NodeContext(view, this.nodeContext,this.msgContext);
+        return new NodeContext(view, this.nodeContext, this.msgContext, undefined, this.promises, this.results);
     };
 
     function TemplateNode(n) {
@@ -83,8 +119,33 @@ module.exports = function(RED) {
 
         var node = this;
         node.on("input", function(msg) {
+            function output(value) {
+                /* istanbul ignore else  */
+                if (node.outputFormat === "json") {
+                    value = JSON.parse(value);
+                }
+                /* istanbul ignore else  */
+                if (node.outputFormat === "yaml") {
+                    value = yaml.load(value);
+                }
+
+                if (node.fieldType === 'msg') {
+                    RED.util.setMessageProperty(msg, node.field, value);
+                    node.send(msg);
+                } else if ((node.fieldType === 'flow') ||
+                           (node.fieldType === 'global')) {
+                    var context = RED.util.parseContextStore(node.field);
+                    var target = node.context()[node.fieldType];
+                    target.set(context.key, value, context.store, function (err) {
+                        if (err) {
+                            node.error(err, msg);
+                        } else {
+                            node.send(msg);
+                        }
+                    });
+                }
+            }
             try {
-                var value;
                 /***
                 * Allow template contents to be defined externally
                 * through inbound msg.template IFF node.template empty
@@ -97,31 +158,18 @@ module.exports = function(RED) {
                 }
 
                 if (node.syntax === "mustache") {
-                    if (node.outputFormat === "json") {
-                        value = mustache.render(template,new NodeContext(msg, node.context(), null, true));
-                    } else {
-                        value = mustache.render(template,new NodeContext(msg, node.context(), null, false));
-                    }
+                    var is_json = (node.outputFormat === "json");
+                    var promises = [];
+                    mustache.render(template, new NodeContext(msg, node.context(), null, is_json, promises, null));
+                    Promise.all(promises).then(function (values) {
+                        var value = mustache.render(template, new NodeContext(msg, node.context(), null, is_json, null, values));
+                        output(value);
+                    }).catch(function (err) {
+                        node.error(err.message);
+                    });
                 } else {
-                    value = template;
+                    output(template);
                 }
-                /* istanbul ignore else  */
-                if (node.outputFormat === "json") {
-                    value = JSON.parse(value);
-                }
-                /* istanbul ignore else  */
-                if (node.outputFormat === "yaml") {
-                    value = yaml.load(value);
-                }
-
-                if (node.fieldType === 'msg') {
-                    RED.util.setMessageProperty(msg,node.field,value);
-                } else if (node.fieldType === 'flow') {
-                    node.context().flow.set(node.field,value);
-                } else if (node.fieldType === 'global') {
-                    node.context().global.set(node.field,value);
-                }
-                node.send(msg);
             }
             catch(err) {
                 node.error(err.message);