How to Read HTML out of a webpage and use it as body of HTML Auto-Responder E-Mail
-
19-09-2019 - |
Question
I am working on an HTML auto responder email. If there is a simpler way than what i am doing please let me know.
So far, i've built "pagename.aspx" and i read this page into a string variable, then use this variable as the BODY of the mail. This works.
The page optionally accepts a QueryString called "leadID". This is used to pull data from a database and populate fields on this page. This also works fine when i manually browse to the page - pagename.aspx?leadid=xyz
My Problem / Question is, how do i pass this querystring to the page and return the resulting HTML output of the page into a string , which can then be used as the body of my email.
Again, if there is a better way please let me know. I'm using LINQ to SQL, VB.NET and ASP.NET 3.5.
Thanks a million.
Solution
The easiest way is just to do a WebRequest
to it:
string url = "...";
string result;
HttpWebRequest webrequest = (HttpWebRequest) HttpWebRequest.Create(url);
webrequest.Method = "GET";
webrequest.ContentLength = 0;
WebResponse response = webrequest.GetResponse();
using(StreamReader stream = new StreamReader(response.GetResponseStream())){
result = stream.ReadToEnd();
}
OTHER TIPS
As described in this article, you could use the HttpWebRequest class to retrieve the stream of data from your page "pagename.aspx?leadID=1". But that could cause a bit of overhead to your application due to the additional HTTP request.
Wouldn't it be possible/better to generate your HTML content from a simple class? What content generates your page?
Edit: As asked by Khalid here is a simple class to generate a dynamic HTML file using your leadID parameter and a gridview control. It's only an example, you would need to custom it and make more reusable:
using System;
using System.Text;
using System.IO;
using System.Web.UI.WebControls;
using System.Web.UI;
public class PageBroker
{
/*
* How to use PageBroker:
*
* string leadID = "xyz"; // dynamic querystring parameter
* string pathToHTML = Server.MapPath(".") + "\\HTML\\leadForm.html"; //more detail about this file below
* PageBroker pLeadBroker = new PageBroker(pathToHTML, leadID);
* Response.Write(pLeadBroker.GenerateFromFile()); // will show content of generated page
*/
private string _pathToFile;
private StringBuilder _fileContent;
private string _leadID;
public PageBroker(string pathToFile, string leadID)
{
_fileContent = new StringBuilder();
_pathToFile = pathToFile;
_leadID = leadID;
}
public string GenerateFromFile() {
return LoadFile();
}
private string LoadFile()
{
// Grab file and load content inside '_fileContent'
// I used an html file to create the basic structure of your page
// but you can also create
// a page from scratch.
if (File.Exists(_pathToFile))
{
FileStream stream = new FileStream(_pathToFile, FileMode.Open, FileAccess.Read);
StreamReader reader = new StreamReader(stream);
while (reader.Peek() > -1)
_fileContent.Append(reader.ReadLine() + "\n");
stream.Close();
reader.Close();
InjectTextContent();
InjectControlsContent();
}
return _fileContent.ToString();
}
// (Ugly) method to inject dynamic values inside the generated html
// You html files need to contain all the necesary tags to place your
// content (for example: '__USER_NAME__')
// It would be more OO if a dictionnary object was passed to the
// constructor of this class and then used inside this method
// (I leave it hard-coded for the sake of understanding but
// I can give you a more detailled code if you need it).
private void InjectTextContent() {
_fileContent.Replace("__USER_NAME__", "Khalid Rahaman");
}
// This method add the render output of the controls you need to place
// on the page. At this point you will make use of your leadID parameter,
// I used a simple array with fake data to fill the gridview.
// You can add whatever control you need.
private void InjectControlsContent() {
string[] products = { "A", "B", "C", "D" };
GridView gvProducts = new GridView();
gvProducts.DataSource = products;
gvProducts.DataBind();
// HtmlTextWriter is used to write HTML programmatically.
// It provides formatting capabilities that ASP.NET server
// controls use when rendering markup to clients
// (http://msdn.microsoft.com/en- us/library/system.web.ui.htmltextwriter.aspx)
// This way you will be able to inject the griview's
// render output inside your file.
StringWriter gvProductsWriter = new StringWriter();
HtmlTextWriter htmlWrit = new HtmlTextWriter(gvProductsWriter);
gvProducts.RenderControl(htmlWrit);
_fileContent.Replace("__GRIDVIEW_PRODUCTS__", gvProductsWriter.ToString());
}
}