Awesomnium Post Parameters

Question

currently i am working with Awsomnium 1.7 in the C# environment. I'm just using the Core and trying to define custom post parameters. Now, i googled a lot and i even posted at the awsomnium forums, but there was no answer. I understand the concept, but the recent changes just dropped the suggested mechanic and examples.

What i found: http://support.awesomium.com/kb/general-use/how-do-i-send-form-values-post-data

The problem with this is, that the WebView Class does not contain "OnResourceRequest" Event anymore. So far, i have implemented the IResourceInterceptor and have the "OnRequest"-Function overwritten public ResourceResponse OnRequest(ResourceRequest request) is the signature, but i have no chance to reach in there in order to add request headers. Anyone here any idea? I tried to look in the documentation, but i didn't find anything on that.....

Answer 1

You need to attach your IResourceInterceptor to WebCore, not WebView. Here's a working example:

Resource interceptor:

public class CustomResourceInterceptor : ResourceInterceptor
{
    protected override ResourceResponse OnRequest(ResourceRequest request)
    {
        request.Method = "POST";
        var bytes = "Appending some text to the request";
        request.AppendUploadBytes(bytes, (uint) bytes.Length);
        request.AppendExtraHeader("custom-header", "this is a custom header");

        return null;
    }
}

Main application:

public MainWindow()
{
    WebCore.Started += WebCoreOnStarted;
    InitializeComponent();
}

private void WebCoreOnStarted(object sender, CoreStartEventArgs coreStartEventArgs)
{
    var interceptor = new CustomResourceInterceptor();

    WebCore.ResourceInterceptor = interceptor;
    //webView is a WebControl on my UI, but you should be able to create your own WebView off WebCore
    webView.Source = new Uri("http://www.google.com");
}

Answer 2

HotN's answer above is good; in fact, it's what I based my answer on. However, I spent a week searching for this information and putting together something that will work. (The answer above has a couple of issues which, at the very least, make it unworkable with v1.7 of Awesomium.) What I was looking for was something that would work right out of the box.

And here is that solution. It needs improvement, but it suits my needs at the moment. I hope this helps someone else.

// CRI.CustomResourceInterceptor
//
// Author:   Garison E Piatt
// Contact:  {removed}
// Created:  11/17/14
// Version:  1.0.0
//
// Apparently, when Awesomium was first created, the programmers did not understand that someone would
// eventually want to post data from the application. So they made it incredibly difficult to upload
// POST parameters to the remote web site. We have to jump through hoops to get that done.
//
// This module provides that hoop-jumping in a simple-to-understand fashion. We hope. It overrides
// the current resource interceptor (if any), replacing both the OnRequest and OnFilterNavigation
// methods (we aren't using the latter yet).
//
// It also provides settable parameters. Once this module is attached to the WebCore, it is *always*
// attached; therefore, we can simply change the parameters before posting to the web site.
//
// File uploads are currently unhandled, and, once handled, will probably only upload one file. We
// will deal with that issue later.
//
// To incoroprate this into your application, follow these steps:
// 1. Add this file to your project. You know how to do that.
// 2. Edit your MainWindow.cs file.
//   a. At the top, add:
//       using CRI;
//   b. inside the main class declaration, near the top, add:
//       private CustomResourceInterceptor cri;
//   c. In the MainWindow method, add:
//       WebCore.Started += OnWebCoreOnStarted;
//       cri = new CustomResourceInterceptor();
//     and (set *before* you set the Source value for the Web Control):
//       cri.Enabled = true;
//       cri.Parameters = String.Format("login={0}&password={1}", login, pw);
//     (Choose your own parameters, but format them like a GET query.)
//   d. Add the following method:
//       private void OnWebCoreOnStarted(object sender, CoreStartEventArgs coreStartEventArgs) {
//         WebCore.ResourceInterceptor = cri;
//       }
// 3. Compile your application. It should work.

using System;
using System.Runtime.InteropServices;
using System.Text;
using Awesomium.Core;
using Awesomium.Windows.Controls;


namespace CRI {
  //* CustomResourceInterceptor
  // This object replaces the standard Resource Interceptor (if any; we still don't know) with something
  // that allows posting data to the remote web site. It overrides both the OnRequest and OnFilterNavigation
  // methods. Public variables allow for run-time configuration.
  public class CustomResourceInterceptor : IResourceInterceptor {
    // Since the default interceptor remains overridden for the remainder of the session, we need to disable
    // the methods herein unless we are actually using them. Note that both methods are disabled by default.
    public bool RequestEnabled = false;
    public bool FilterEnabled = false;

    // These are the parameters we send to the remote site. They are empty by default; another safeguard
    // against sending POST data unnecessarily. Currently, both values allow for only one string. POST
    // variables can be combined (by the caller) into one string, but this limits us to only one file
    // upload at a time. Someday, we will have to fix that. And make it backward-compatible.
    public String Parameters = null;
    public String FilePath = null;

    /** OnRequest
    ** This ovverrides the default OnRequest method of the standard resource interceptor. It receives
    ** the resource request object as a parameter.
    **
    ** It first checks whether or not it is enabled, and returns NULL if not. Next it sees if any
    ** parameters are defined. If so, it converst them to a byte stream and appends them to the request.
    ** Currently, files are not handled, but we hope to add that someday.
    */
    public ResourceResponse OnRequest(ResourceRequest request) {
      // We do nothing at all if we aren't enabled. This is a stopgap that prevents us from sending
      // POST data with every request.
      if (RequestEnabled == false) return null;

      // If the Parameters are defined, convert them to a byte stream and append them to the request.
      if (Parameters != null) {
        var str = Encoding.Default.GetBytes(Parameters);
        var bytes = Encoding.UTF8.GetString(str);

        request.AppendUploadBytes(bytes, (uint)bytes.Length);
      }

      // If either the parameters or file path are defined, this is a POST request. Someday, we'll
      // figure out how to get Awesomium to understand Multipart Form data.
      if (Parameters != null || FilePath != null) {
        request.Method = "POST";
        request.AppendExtraHeader("Content-Type", "application/x-www-form-urlencoded"); //"multipart/form-data");
      }

      // Once the data has been appended to the page request, we need to disable this process. Otherwise,
      // it will keep adding the data to every request, including those that come from the web site.
      RequestEnabled = false;
      Parameters = null;
      FilePath = null;

      return null;
    }


    /** OnFilterNavigation
    ** Not currently used, but needed to keep VisualStudio happy.
    */
    public bool OnFilterNavigation(NavigationRequest request) {
      return false;
    }
  }
}