code cleanup, kinda

README.md

@@ -1,8 +1,7 @@
 # XHR eXtensions
-Prototype modifications that enable manipulating and listening to XmlHttpRequests throughout their life-cycle.
+Prototype modifications enabling manipulation and snooping of XMLHttpRequests.
 
 ## Why?
-Its primary purpose is for reverse engineering. \
-Used in some of my own projects.
+To aid in personal reverse engineering projects.
 - [winnpixie/socialrip](https://github.com/winnpixie/socialrip)
-- [winnpixie/anypin](https://github.com/winnpixie/anypin) (now defunct)
+- [winnpixie/anypin](https://github.com/winnpixie/anypin)

xhr-x.js

@@ -0,0 +1,116 @@
+(function () {
+    'use strict';
+
+    // BEGIN Event declarations
+    class XHREvent {
+        constructor(context) {
+            this.context = context;
+
+            this.cancelled = false;
+        }
+    }
+
+    class XHROpenEvent extends XHREvent {
+        constructor(context, state) {
+            super(context);
+
+            this.state = state;
+        }
+    }
+
+    class XHRHeaderSetEvent extends XHREvent {
+        constructor(context, key, value) {
+            super(context);
+
+            this.key = key;
+            this.value = value;
+        }
+    }
+
+    class XHRSendEvent extends XHREvent {
+        constructor(context, state) {
+            super(context);
+
+            this.state = state;
+        }
+    }
+
+    class XHRFinishedEvent extends XHREvent {
+        constructor(context) {
+            super(context);
+        }
+    }
+    // END Event declarations
+
+    const XHRExt = {
+        openHandlers: [],
+        headerSetHandlers: [],
+        sendHandlers: [],
+        finishHandlers: []
+    };
+    window.XHRExt = XHRExt;
+
+    // BEGIN Prototype hacking
+    const xhr_open = XMLHttpRequest.prototype.open;
+    XMLHttpRequest.prototype.open = function () {
+        this.xMethod = arguments[0];
+        this.xUrl = arguments[1];
+        this.xAsync = arguments[2] || false;
+        this.xUsername = arguments[3];
+        this.xPassword = arguments[4];
+
+        let xhrEvent = new XHROpenEvent(this, "before");
+        XHRExt.openHandlers.forEach(handler => handler.call(null, xhrEvent));
+        if (xhrEvent.cancelled) return;
+
+        arguments[0] = this.xMethod;
+        arguments[1] = this.xUrl;
+        arguments[2] = this.xAsync;
+        arguments[3] = this.xUsername;
+        arguments[4] = this.xPassword;
+
+        xhr_open.apply(this, arguments);
+        XHRExt.openHandlers.forEach(handler => handler.call(null, new XHROpenEvent(this, "after")));
+    };
+
+    const xhr_setRequestHeader = XMLHttpRequest.prototype.setRequestHeader;
+    XMLHttpRequest.prototype.setRequestHeader = function () {
+        if (this.xHeaders == null) this.xHeaders = [];
+
+        this.xHeaders[arguments[0]] = arguments[1];
+
+        let xhrEvent = new XHRHeaderSetEvent(this, arguments[0], arguments[1]);
+        XHRExt.headerSetHandlers.forEach(handler => handler.call(null, xhrEvent));
+        if (xhrEvent.cancelled) return;
+
+        this.xHeaders[xhrEvent.key] = xhrEvent.value;
+        arguments[0] = xhrEvent.key;
+        arguments[1] = xhrEvent.value;
+
+        xhr_setRequestHeader.apply(this, arguments);
+    };
+
+    const xhr_send = XMLHttpRequest.prototype.send;
+    XMLHttpRequest.prototype.send = function () {
+        this.xBody = arguments[0];
+
+        let xhrEvent = new XHRSendEvent(this, "before");
+        XHRExt.sendHandlers.forEach(handler => handler.call(null, xhrEvent));
+        if (xhrEvent.cancelled) return;
+
+        arguments[0] = this.xBody;
+
+        const xhr_onreadystatechange = this.onreadystatechange;
+        this.onreadystatechange = function () {
+            if (this.readyState === XMLHttpRequest.DONE) {
+                XHRExt.finishHandlers.forEach(handler => handler.call(null, new XHRFinishedEvent(this)));
+            }
+
+            if (xhr_onreadystatechange != null) xhr_onreadystatechange.apply(this, arguments);
+        };
+
+        xhr_send.apply(this, arguments);
+        XHRExt.sendHandlers.forEach(handler => handler.call(null, new XHRSendEvent(this, "after")));
+    };
+    // END Prototype hacking
+})();