We have a 3rd party API that sends back a HTTP "POST" page to us using a URL that we specify. The ashx page that we are receiving needs to read the data returned from various fields. Below is how I was told to get each piece of data and just wanted to verify.
Dim contextData1 As String = CStr((HttpContext.Current.Items("TranRef")))
Dim contextData2 As String = CStr((HttpContext.Current.Items("TranAmt")))
etc.
First of all, HttpContext.Items Property is used to share data between an IHttpModule interface and an IHttpHandler interface
during an HTTP request. As you may know, each and every client request passes through the HTTP Pipeline and HTTP Pipeline consists of HTTP Module and HTTP Handler. So If you
are writing one custom HTTP Module by Implementing IHttpModule and you want pass some information from this module to the current requested page or any other module, you can use the HttpContext.Current.Items to store the data.
To summarize, in ASP.NET, HttpContext.Current.Items allows us to hold information for a single request.
dlchase
We have a 3rd party API that sends back a HTTP "POST" page to us using a URL that we specify.
However, I can read from above that you will get a "HTTP POST Page" from a 3rd party API.
How could you get the data from HttpContext.Items Property? It seems like no one stores the data in the HttpContext.Items so that you could not get the data from it.
If the value is contained in few specific html fields/elements, you could parse the returned html and fetch the value using
HtmlAgilityPack.
If I misunderstand your problem, please feel free to let me know.
We are going to use an online payment system that sends payment receipt information back like accepted/failed, transaction number, etc. that we need to read from our web page (handler ashx page). We will then be able to store those items in our database,
etc. Does that help explain? Would context.request be a way to do that?
First of all, I think you need to understand what kind of the result you will get from that payment system.
What I am guessing is that it is like a web api and will return you with a
json format information. Correct?
However, if it is a html page, you might need to think about using HtmlAgilityPack to parse the page and find out the data you want.
You could refer to below codes for more details.
Note that I use a button click to simulate the call back from the online payment system and post some information via
json string.
Simulation from the button click:
<head runat="server">
<title></title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>
</head>
<body>
<script>
$(function () {
$("#bntSubmit").on('click', function (e) {
// Initialize the object, before adding data to it.
// { } is declarative shorthand for new Object()
var obj = {};
obj.accepted = "true";
obj.transaction_number = "123456";
//In order to proper pass a json string, you have to use function JSON.stringfy
var jsonData = JSON.stringify(obj);
$.ajax({
url: 'PaymentHandler.ashx',
type: 'POST',
data: jsonData,
success: function (data) {
console.log(data);
alert("Success :" + data);
},
error: function (errorText) {
alert("Wwoops something went wrong !");
}
});
e.preventDefault();
});
})
</script>
<form id="form1" runat="server">
<div>
<button id="bntSubmit">Submit</button>
</div>
</form>
</body>
PaymentHandler.ashx.cs: To read the json data
public class PaymentHandler : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
try
{
string strJson = new StreamReader(context.Request.InputStream).ReadToEnd();
//deserialize the object
PaymentInfo objPayment = JsonConvert.DeserializeObject<PaymentInfo>(strJson);
if (objPayment != null)
{
string accepted = objPayment.accepted.ToString();
string transaction_number = objPayment.transaction_number.ToString();
context.Response.Write(string.Format("Accepted :{0} , Transaction Number={1}", accepted, transaction_number));
}
else
{
context.Response.Write("No Data");
}
}
catch (Exception ex)
{
context.Response.Write("Error :" + ex.Message);
}
}
public bool IsReusable
{
get
{
return false;
}
}
public class PaymentInfo
{
public bool accepted { get; set; }
public int transaction_number { get; set; }
}
}
Demo:
Here I only focus on reading data from the call back.
If you still have any question, feel free to let me know.
If you don't want to use any other 3rd party tool to read an html page, then I would suggest you use either string methods (e.g. IndexOf) or Regular expression to target the areas.
For example, I will use below html codes to fetch the value inside the label "accepted" and "transaction_number".
Simulation from the button click:
<script>
$(function () {
$("#bntSubmit").on('click', function (e) {
// Post a html page to PaymentHandler
var html = '<!DOCTYPE html>'
+ '<html>'
+ '<head>'
+ '<title>Page Example</title>'
+ '</head>'
+ '<body>'
+ '<label id="accepted">true</label>'
+ '<label id="transaction_number">123456</label>'
+ '</body>'
+ '</html>';
// Prove that the PaymentHandler got the page and extract the information.
$.ajax({
url: 'PaymentHandler.ashx',
type: 'POST',
data: html,
success: function (data) {
console.log(data);
alert("Success : " + data);
},
error: function (errorText) {
alert("Wwoops something went wrong !");
}
});
e.preventDefault();
});
})
</script>
<form id="form1" runat="server">
<div>
<button id="bntSubmit">Submit</button>
</div>
</form>
PaymentHandler.ashx.cs
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
string accepted = null, transaction_number = null;
try
{
string strJson = new StreamReader(context.Request.InputStream).ReadToEnd();
// Regex: [\w ] allow the area contains spaces
Regex regex = new Regex("<label id=\"(?<id>[\\w ]+)\">(?<value>[\\w ]*)<\\/label>");
MatchCollection matches = regex.Matches(strJson);
foreach (Match match in matches)
{
GroupCollection groups = match.Groups;
if (groups["id"] != null)
{
switch (groups["id"].Value)
{
case "accepted":
accepted = groups["value"].Value;
break;
case "transaction_number":
transaction_number = groups["value"].Value;
break;
default: break;
}
}
}
context.Response.Write(string.Format("Accepted :{0} , Transaction Number={1}", accepted, transaction_number));
}
catch (Exception ex)
{
context.Response.Write("Error :" + ex.Message);
}
}
public bool IsReusable
{
get
{
return false;
}
}
public class PaymentInfo
{
public bool accepted { get; set; }
public int transaction_number { get; set; }
}
I am using an IHttpHandler (see below). The form content loop brings back nothing.
Public Class PayHandler : Implements IHttpHandler
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
context.Response.ContentType = "text/plain"
'context.Response.Write("Hello World")
Dim loop1 As Integer
Dim coll As NameValueCollection
coll = context.Request.Form
Dim arr1 As String() = coll.AllKeys
Dim strText As String = ""
Dim path As String = "c:\W_Drive\ReadForm.txt"
If Not File.Exists(path) Then
Using sw As StreamWriter = File.CreateText(path)
For loop1 = 0 To arr1.Length - 1
sw.WriteLine("Form: " & arr1(loop1))
Next
If Not context.Request("x_amount") Is Nothing Then
sw.WriteLine("x_amount: " & context.Request("x_amount"))
End If
If Not context.Request("DollarAmount") Is Nothing Then
sw.WriteLine("DollarAmount: " & context.Request("DollarAmount"))
End If
If Not context.Request("x_response_code") Is Nothing Then
sw.WriteLine("x_response_code: " & context.Request("x_response_code"))
End If
If Not context.Request("x_fp_sequence") Is Nothing Then
sw.WriteLine("x_fp_sequence: " & context.Request("x_fp_sequence"))
End If
If Not context.Request("x_fp_timestamp") Is Nothing Then
sw.WriteLine("x_fp_timestamp: " & context.Request("x_fp_timestamp"))
End If
End Using
End If
End Sub
Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
Get
Return False
End Get
End Property
End Class
Public Class PayHandler
Implements System.Web.IHttpHandler
Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
context.Response.ContentType = "text/plain"
Dim path = "C:\test\" & Guid.NewGuid().ToString() & ".txt"
context.Request.SaveAs(path, True)
For Each key In context.Request.Form.AllKeys
System.IO.File.AppendAllText(path, System.Environment.NewLine & key & "=" & context.Request.Form(key))
Next
End Sub
ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
Get
Return False
End Get
End Property
End Class
Member
344 Points
1513 Posts
Reading POST content
Aug 13, 2020 09:49 PM|dlchase|LINK
We have a 3rd party API that sends back a HTTP "POST" page to us using a URL that we specify. The ashx page that we are receiving needs to read the data returned from various fields. Below is how I was told to get each piece of data and just wanted to verify.
Dim contextData1 As String = CStr((HttpContext.Current.Items("TranRef"))) Dim contextData2 As String = CStr((HttpContext.Current.Items("TranAmt"))) etc.Participant
1900 Points
562 Posts
Re: Reading POST content
Aug 14, 2020 02:43 AM|Sean Fang|LINK
Hi dlchase,
First of all, HttpContext.Items Property is used to share data between an IHttpModule interface and an IHttpHandler interface
during an HTTP request. As you may know, each and every client request passes through the HTTP Pipeline and HTTP Pipeline consists of HTTP Module and HTTP Handler. So If you
are writing one custom HTTP Module by Implementing
IHttpModuleand you want pass some information from this module to the current requested page or any other module, you can use theHttpContext.Current.Itemsto store the data.To summarize, in ASP.NET,
HttpContext.Current.Itemsallows us to hold information for a single request.However, I can read from above that you will get a "HTTP POST Page" from a 3rd party API.
How could you get the data from HttpContext.Items Property? It seems like no one stores the data in the HttpContext.Items so that you could not get the data from it.
If the value is contained in few specific html fields/elements, you could parse the returned html and fetch the value using HtmlAgilityPack.
If I misunderstand your problem, please feel free to let me know.
Best regards,
Sean
Member
344 Points
1513 Posts
Re: Reading POST content
Aug 14, 2020 01:02 PM|dlchase|LINK
We are going to use an online payment system that sends payment receipt information back like accepted/failed, transaction number, etc. that we need to read from our web page (handler ashx page). We will then be able to store those items in our database, etc. Does that help explain? Would context.request be a way to do that?
Participant
1900 Points
562 Posts
Re: Reading POST content
Aug 17, 2020 08:04 AM|Sean Fang|LINK
Hi dlchase,
First of all, I think you need to understand what kind of the result you will get from that payment system.
What I am guessing is that it is like a web api and will return you with a json format information. Correct?
However, if it is a html page, you might need to think about using HtmlAgilityPack to parse the page and find out the data you want.
You could refer to below codes for more details.
Note that I use a button click to simulate the call back from the online payment system and post some information via json string.
Simulation from the button click:
<head runat="server"> <title></title> <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script> </head> <body> <script> $(function () { $("#bntSubmit").on('click', function (e) { // Initialize the object, before adding data to it. // { } is declarative shorthand for new Object() var obj = {}; obj.accepted = "true"; obj.transaction_number = "123456"; //In order to proper pass a json string, you have to use function JSON.stringfy var jsonData = JSON.stringify(obj); $.ajax({ url: 'PaymentHandler.ashx', type: 'POST', data: jsonData, success: function (data) { console.log(data); alert("Success :" + data); }, error: function (errorText) { alert("Wwoops something went wrong !"); } }); e.preventDefault(); }); }) </script> <form id="form1" runat="server"> <div> <button id="bntSubmit">Submit</button> </div> </form> </body>PaymentHandler.ashx.cs: To read the json data
public class PaymentHandler : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/plain"; try { string strJson = new StreamReader(context.Request.InputStream).ReadToEnd(); //deserialize the object PaymentInfo objPayment = JsonConvert.DeserializeObject<PaymentInfo>(strJson); if (objPayment != null) { string accepted = objPayment.accepted.ToString(); string transaction_number = objPayment.transaction_number.ToString(); context.Response.Write(string.Format("Accepted :{0} , Transaction Number={1}", accepted, transaction_number)); } else { context.Response.Write("No Data"); } } catch (Exception ex) { context.Response.Write("Error :" + ex.Message); } } public bool IsReusable { get { return false; } } public class PaymentInfo { public bool accepted { get; set; } public int transaction_number { get; set; } } }Demo:
Here I only focus on reading data from the call back.
If you still have any question, feel free to let me know.
Best regards,
Sean
Member
344 Points
1513 Posts
Re: Reading POST content
Aug 17, 2020 12:51 PM|dlchase|LINK
I shouldn't need a 3rd party tool to read an html "post" page. I already know the names of the fields they will send back.
Participant
1900 Points
562 Posts
Re: Reading POST content
Aug 18, 2020 08:55 AM|Sean Fang|LINK
Hi dlchase,
If you don't want to use any other 3rd party tool to read an html page, then I would suggest you use either string methods (e.g. IndexOf) or Regular expression to target the areas.
For example, I will use below html codes to fetch the value inside the label "accepted" and "transaction_number".
Simulation from the button click:
<script> $(function () { $("#bntSubmit").on('click', function (e) { // Post a html page to PaymentHandler var html = '<!DOCTYPE html>' + '<html>' + '<head>' + '<title>Page Example</title>' + '</head>' + '<body>' + '<label id="accepted">true</label>' + '<label id="transaction_number">123456</label>' + '</body>' + '</html>'; // Prove that the PaymentHandler got the page and extract the information. $.ajax({ url: 'PaymentHandler.ashx', type: 'POST', data: html, success: function (data) { console.log(data); alert("Success : " + data); }, error: function (errorText) { alert("Wwoops something went wrong !"); } }); e.preventDefault(); }); }) </script> <form id="form1" runat="server"> <div> <button id="bntSubmit">Submit</button> </div> </form>PaymentHandler.ashx.cs
public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/plain"; string accepted = null, transaction_number = null; try { string strJson = new StreamReader(context.Request.InputStream).ReadToEnd(); // Regex: [\w ] allow the area contains spaces Regex regex = new Regex("<label id=\"(?<id>[\\w ]+)\">(?<value>[\\w ]*)<\\/label>"); MatchCollection matches = regex.Matches(strJson); foreach (Match match in matches) { GroupCollection groups = match.Groups; if (groups["id"] != null) { switch (groups["id"].Value) { case "accepted": accepted = groups["value"].Value; break; case "transaction_number": transaction_number = groups["value"].Value; break; default: break; } } } context.Response.Write(string.Format("Accepted :{0} , Transaction Number={1}", accepted, transaction_number)); } catch (Exception ex) { context.Response.Write("Error :" + ex.Message); } } public bool IsReusable { get { return false; } } public class PaymentInfo { public bool accepted { get; set; } public int transaction_number { get; set; } }Demo:
Hope this can help you.
Best regards,
Sean
All-Star
47690 Points
17659 Posts
Re: Reading POST content
Aug 18, 2020 09:21 AM|PatriceSc|LINK
Hi,
If you want to rread posted form fields you'll use https://docs.microsoft.com/en-us/dotnet/api/system.web.httprequest.form?view=netframework-4.8
If
Dim contextData1 As String = HttpContext.Current.Request.Form("TranRef")Dim contextData2 As String = HttpContext.Current.Request.Form("TranAmt")
doesn't work you could start by dumping all form fields to see if they are what you expect.
Member
344 Points
1513 Posts
Re: Reading POST content
Aug 20, 2020 07:19 PM|dlchase|LINK
Below is what they gave me as a sample response POST.
All-Star
47690 Points
17659 Posts
Re: Reading POST content
Aug 20, 2020 08:30 PM|PatriceSc|LINK
Ok and so what if you try:
Member
344 Points
1513 Posts
Re: Reading POST content
Aug 20, 2020 08:58 PM|dlchase|LINK
I am using an IHttpHandler (see below). The form content loop brings back nothing.
Public Class PayHandler : Implements IHttpHandler Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest context.Response.ContentType = "text/plain" 'context.Response.Write("Hello World") Dim loop1 As Integer Dim coll As NameValueCollection coll = context.Request.Form Dim arr1 As String() = coll.AllKeys Dim strText As String = "" Dim path As String = "c:\W_Drive\ReadForm.txt" If Not File.Exists(path) Then Using sw As StreamWriter = File.CreateText(path) For loop1 = 0 To arr1.Length - 1 sw.WriteLine("Form: " & arr1(loop1)) Next If Not context.Request("x_amount") Is Nothing Then sw.WriteLine("x_amount: " & context.Request("x_amount")) End If If Not context.Request("DollarAmount") Is Nothing Then sw.WriteLine("DollarAmount: " & context.Request("DollarAmount")) End If If Not context.Request("x_response_code") Is Nothing Then sw.WriteLine("x_response_code: " & context.Request("x_response_code")) End If If Not context.Request("x_fp_sequence") Is Nothing Then sw.WriteLine("x_fp_sequence: " & context.Request("x_fp_sequence")) End If If Not context.Request("x_fp_timestamp") Is Nothing Then sw.WriteLine("x_fp_timestamp: " & context.Request("x_fp_timestamp")) End If End Using End If End Sub Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable Get Return False End Get End Property End ClassAll-Star
47690 Points
17659 Posts
Re: Reading POST content
Aug 21, 2020 11:06 AM|PatriceSc|LINK
It seems it shoudl work. You could start perhaps with a test page such as:
<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="WebForm1.aspx.vb" Inherits="vb48.WebForm1" %> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title></title> </head> <body> <form id="form1" runat="server" action="PayHandler.ashx"> <div> <input type="text" name="SequenceNo" value="435677" /> <input type="text" name="Language" value="1" /> <input type="submit" /> </div> </form> </body> </html>with PayHandler.ashx being:
Public Class PayHandler Implements System.Web.IHttpHandler Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest context.Response.ContentType = "text/plain" Dim path = "C:\test\" & Guid.NewGuid().ToString() & ".txt" context.Request.SaveAs(path, True) For Each key In context.Request.Form.AllKeys System.IO.File.AppendAllText(path, System.Environment.NewLine & key & "=" & context.Request.Form(key)) Next End Sub ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable Get Return False End Get End Property End Classwhich gives something such as:
Edit: are you sure it is currently a POST request rather than a GET request ?
Member
344 Points
1513 Posts
Re: Reading POST content
Aug 21, 2020 11:35 AM|dlchase|LINK
Thank you.