Add option to pass non matching XmlNodes

README.md

@@ -1,4 +1,3 @@
-
 # Xtreamer
 
 [![npm version][npm-image]][npm-url]
@@ -115,7 +114,7 @@ xtreamerTransform.on("data", (data) => { });
 
 ### max_xml_size ( default - 10000000 )
 
-`max_xml_size` is maximum the number of characters allowed to hold in memory. 
+`max_xml_size` is maximum the number of characters allowed to hold in memory.
 
 `xtreamer` raises an `error` event in case in memory xml string exceed specified limit. This ensures that the node process doesn't get terminated because of excess in memory data collection.
 
@@ -145,6 +144,34 @@ Note that the converted JSON is internally stringified before sending it back to
 
 In case transformer function encounters an error, `xtreamer` emits `error` event and stops the xml conversion process.
 
+## pass_all_nodes (default - false)
+
+`pass_all_nodes` defines whether to pass only matching nodes or all of them.
+
+This can be helpful when modifying an XML document on the fly without loosing non matching nodes.
+
+```javascript
+const xtreamer = require("xtreamer");
+// Override `pass_all_nodes`
+const options = {  pass_all_nodes: true };
+const xtreamer = Xtreamer("XmlNode", options)
+```
+
+The receiving function must verify before processing, i.e.
+```javascript
+// A piped transformer
+async _transform(chunk, enc, done) {
+  if (Buffer.isBuffer(chunk)) chunk = chunk.toString();
+  if (!chunk.startsWith("<XmlNode")) {
+      // Not interesting, just pipe out
+      this.push(chunk);
+  }
+  // Do something with an interesting matching node as usual
+  this.push(chunk + "\n");
+  done();
+}
+```
+
 ## Usage
 
 Following code snippet uses `request` NPM package as input readable stream -

lib/index.js

@@ -20,6 +20,9 @@ class Xtreamer extends Transform {
     }
 
     _flush(done) {
+        if (this._options.pass_all_nodes) {
+          this.push(this._xmlString.trim());
+        }
         done();
     }
 
@@ -31,10 +34,21 @@ class Xtreamer extends Transform {
         }
         const nodeIndices = getNodeIndices(this._xmlString, this._node);
         let nodes = [];
+        let fromIndex = 0;
+
         for (let index = 0; index < nodeIndices.length; index++) {
             const nodeObj = nodeIndices[index];
             const endIndex = nodeObj.end + this._node.length + 3;
             const xmlNode = this._xmlString.slice(nodeObj.start, endIndex);
+
+            if (this._options.pass_all_nodes) {
+               const otherNode = this._xmlString.slice(fromIndex, nodeObj.start).trim();
+               fromIndex = endIndex;
+               if (otherNode.length > 0) {
+                   this.push(otherNode);
+                   nodes.push(otherNode);
+               }
+            }
             this._options && this._options.transformer && typeof this._options.transformer === "function" ?
                 this.push(JSON.stringify(await this._options.transformer(xmlNode))) :
                 this.push(xmlNode);
@@ -52,4 +66,4 @@ module.exports = (node, options = { max_xml_size: Constants.MAX_XML_LENGTH }) =>
     options = options || {};
     options.max_xml_size = options.max_xml_size || Constants.MAX_XML_LENGTH;
     return new Xtreamer(node, options);
-};
+};

package.json

@@ -1,6 +1,6 @@
 {
     "name": "xtreamer",
-    "version": "1.1.2",
+    "version": "1.1.3",
     "description": "A NodeJS package to read XML files using NodeJS streams.",
     "main": "lib/index.js",
     "scripts": {