Flex HttpService : appending to destination - apache-flex

I am using Flex to connect to a Rest service. To access order #32, for instance, I can call the URL http://[service]/orders/32.
The URL must be configured as a destination - since the client will connect to different instances of the service. All of this is using the Blaze Proxy, since it involves GET, PUT, DELETE and POST calls.
The problem is:- how do I append the "32" to the end of a destination when using HttpService? All I do is set the destination, and at some point this is converted into a URL. I have traced the code, but I don't know where this is done, so can't replace it.
Options are:
1. Resolve the destination to a URL within the Flex client, and then set the URL (with the appended data) as the URL.
2. Write my own java Flex Adapter that overrides the standard Proxy, and map parameters to the url like the following: http://[service]/order/{id}?id=32 to http://[service]/order/32
Has anyone come across this problem before, and are there any simple ways to resolve this?

Just so everyone knows, this is how I resolved this issue:
I created a custom HTTPProxyAdapter on the server
public MyHTTPProxyAdapter extends flex.messaging.services.http.HTTPProxyAdapter {
public Object invoke(Message message) {
// modify the message - if required
process(message);
return super.invoke(message);
}
private void process(Message message) {
HTTPMessage http = (HTTPMessage)message;
if(http != null) {
String url = http.getUrl();
ASObject o = (ASObject)http.getBody();
if(o != null) {
Set keys = o.keySet();
Iterator it = keys.iterator();
while(it.hasNext()) {
String key = (String)it.next();
String token = "[" + key +"]";
if(url.contains(token)) {
url = url.replace(token, o.get(key).toString());
o.remove(key);
}
}
http.setUrl(url);
}
}
}
}
Then replaced the destination adapter to my adapter.
I can now use the following URL in the config.xml and anything in square brackets will be replaced by the Query string:
<destination id="user-getbytoken">
<properties>
<url>http://localhost:8080/myapp/public/client/users/token/[id]</url>
</properties>
</destination>
In this example, setting the destination to user-getbytoken and the parameters {id:123} will result in the url of http://localhost:8080/myapp/public/client/users/token/123

Here's a simple way to resolve the url to the HTTPService within Flex via the click event's handler.
here's a service:
<mx:HTTPService
id="UCService"
result="UCServiceHandler(event)"
showBusyCursor="true"
resultFormat="e4x"
/>
Then here's the handler:
private function UCmainHandler(UCurl:String) {
UCService.url = UCurl;
UCService.send();
}
And here's a sample click event:
<mx:Button label="add to cart" click="UCmainHandler('http://sampleurl.com/cart/add/p18_q1?destination=cart')" />
Of course you could pass other values to the click handler, or even have the handler add things to the url based on other current settings etc...
Hope that helps!

Related

.Net Core 3.1 Razor Pages : autoredirect to culture

I try to accomplish a similar behaviour with MS Docs.
For example, if you visit https://learn.microsoft.com/, you will be redirected to your culture, in my case I'm being redirected automatically to https://learn.microsoft.com/en-gb/.
Same goes for inner pages if you access them without the culture in the URL.
For instance, by accessing:
https://learn.microsoft.com/aspnet/core/razor-pages/?view=aspnetcore-3.1&tabs=visual-studio
it will be automatically redirect you to:
https://learn.microsoft.com/en-gb/aspnet/core/razor-pages/?view=aspnetcore-3.1&tabs=visual-studio
I have a small demo app where I conduct my localisation experiment for .NET Core 3.1 and Razor Pages here.
I have set options.Conventions here, and I have created CustomCultureRouteRouteModelConvention class here, but I'm fairly novice with .NET Core and I'm kind of stuck on how to implement the above-described functionality.
Thank you all in advance!
You should use existing Rewriting Middleware to do redirects: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/url-rewriting?view=aspnetcore-3.1
In the simplest form, you can tell rewrite middleware to redirect if it does not see a locale pattern at the beginning of the URL path, maybe
new RewriteOptions() .AddRedirect("^([a-z]{2}-[a-z]{2})", "en-US/$1")
(regex not tested) or do full redirect class with more detailed rules when and to what locale you want to redirect. Example in that aspnet document references RedirectImageRequest which you can use to get an understanding of how custom redirect rules works. Adapting to your case as a proof of concept, I reused most of the logic in your existing RedirectUnsupportedCulture:
public class RedirectUnsupportedCultures : IRule
{
private readonly string _extension;
private readonly PathString _newPath;
private IList<CultureInfo> _cultureItems;
private string _cultureRouteKey;
public RedirectUnsupportedCultures(IOptions<RequestLocalizationOptions> options)
{
RouteDataRequestCultureProvider provider = options.Value.RequestCultureProviders
.OfType<RouteDataRequestCultureProvider>()
.First();
_cultureItems = options.Value.SupportedUICultures;
_cultureRouteKey = provider.RouteDataStringKey;
}
public void ApplyRule(RewriteContext rewriteContext)
{
// do not redirect static assets and do not redirect from a controller that is meant to set the locale
// similar to how you would not restrict a guest user from login form on public site.
if (rewriteContext.HttpContext.Request.Path.Value.EndsWith(".ico") ||
rewriteContext.HttpContext.Request.Path.Value.Contains("change-culture"))
{
return;
}
IRequestCultureFeature cultureFeature = rewriteContext.HttpContext.Features.Get<IRequestCultureFeature>();
string actualCulture = cultureFeature?.RequestCulture.Culture.Name;
string requestedCulture = rewriteContext.HttpContext.GetRouteValue(_cultureRouteKey)?.ToString();
// Here you can add more rules to redirect based on maybe cookie setting, or even language options saved in database user profile
if(string.IsNullOrEmpty(requestedCulture) || _cultureItems.All(x => x.Name != requestedCulture)
&& !string.Equals(requestedCulture, actualCulture, StringComparison.OrdinalIgnoreCase))
{
string localizedPath = $"/{actualCulture}{rewriteContext.HttpContext.Request.Path.Value}";
HttpResponse response = rewriteContext.HttpContext.Response;
response.StatusCode = StatusCodes.Status301MovedPermanently;
rewriteContext.Result = RuleResult.EndResponse;
// preserve query part parameters of the URL (?parameters) if there were any
response.Headers[HeaderNames.Location] =
localizedPath + rewriteContext.HttpContext.Request.QueryString;
}
}
and registered it in Startup.cs with
// Attempt to make auto-redirect to culture if it is not exist in the url
RewriteOptions rewriter = new RewriteOptions();
rewriter.Add(new RedirectUnsupportedCultures(app.ApplicationServices.GetService<IOptions<RequestLocalizationOptions>>()));
app.UseRewriter(rewriter);
Improvement:
After using the above code I bumped on a bug that in case the culture is not supported by the application, the redirection will end up with infinite culture paths. For example, if I support the cultures en (default) and gr, if instead of either /en/foobar or /gr/foobar I would write /fr/foobar, I would end up getting /en/fr/foobar then /en/en/fr/foobar and etc.
I added private readonly LinkGenerator _linkGenerator; to the class, which I initialise it in the constructor. I removed that line string localizedPath = $"/{actualCulture}{rewriteContext.HttpContext.Request.Path.Value}"; and the code after that line looks like this:
rewriteContext.HttpContext.GetRouteData().Values[_cultureRouteKey] = actualCulture;
HttpResponse response = rewriteContext.HttpContext.Response;
response.StatusCode = StatusCodes.Status301MovedPermanently;
rewriteContext.Result = RuleResult.EndResponse;
// preserve query part parameters of the URL (?parameters) if there were any
response.Headers[HeaderNames.Location] =
_linkGenerator.GetPathByAction(
rewriteContext.HttpContext,
values: rewriteContext.HttpContext.GetRouteData().Values
)
+ rewriteContext.HttpContext.Request.QueryString;
As decribed in Microsoft docs localization middleware; each the localization request initializes a list of RequestCultureProvider and is enumerated by the below order :
QueryStringRequestCultureProvider : e.g. http://localhost:1234/Index?culture=en
CookieRequestCultureProvider : Looks for the culture cookie, and it will be null if you haven't set it manually.
AcceptLanguageHeaderRequestCultureProvider : This one depends on the browsers cultures adn this is what you need to look for.
To make sure how it works, delete the culture cookie and change the browser language preferences by moving the desired language to the top, you will see that the language is selected according to the browser preferences.

Different ways to set url path in base tag in mvc website

Hi i am just passing url like this in my MVC website:
<base href="http:4546//localhost/" />
It works in local but if i am hosting it on ISS.This url creates issues.
If i am removing 4546 in url like this:
http://localhost/Home/Contact
Then its working.
I tried it by removing port number in code but still in url port number displays itself.
how i can remove port number or what will be the way so i can host it with port number 80 on public?
Please let me know where i am lacking.
Thanks
You can create one Base Controller and add this method
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
base.OnActionExecuting(filterContext);
var request = HttpContext.Request;
var baseUrl = string.Format("{0}://{1}{2}", request.Url.Scheme, request.Url.Authority, HttpRuntime.AppDomainAppVirtualPath == "/" ? "" : HttpRuntime.AppDomainAppVirtualPath);
ViewBag.BasePath = baseUrl;
}
This method OnActionExecuting will always be called on each request and user this viewbag in you code.
This will resolve your issue of writting every where in code.
I was running into a similar issue where, on certain IIS configurations, the base tag (which is necessary for AngularJS) was providing the incorrect address. The way I got around this is by replacing <base href="/"> with:
<base href="#(string.Format("{0}://{1}{2}/", HttpContext.Current.Request.Url.Scheme, HttpContext.Current.Request.Url.Authority, HttpRuntime.AppDomainAppVirtualPath == "/" ? "" : HttpRuntime.AppDomainAppVirtualPath))">
This is basically a shorter version of Sulay's solution, but it has worked for me so far.
My need to set base tag stems from using AngularJS as it requires base for correct routing, if html5 mode is on.
I ended up with this method:
private const string Action = "action";
private const string Controller = "controller";
public static string CurrentActionWithoutRouteReuse(this UrlHelper urlHelper)
{
var routeValues = urlHelper.RequestContext.RouteData.Values;
var actionName = (string)routeValues[Action];
var controllerName = (string)routeValues[Controller];
var routeValuesWithoutParams = new RouteValueDictionary(routeValues);
routeValuesWithoutParams.Remove(Action);
routeValuesWithoutParams.Remove(Controller);
routeValuesWithoutParams.Keys
.ToList().ForEach(parameterName => routeValuesWithoutParams[parameterName] = null);
var url = urlHelper.Action(actionName, controllerName, routeValuesWithoutParams);
return url.EndsWith("/") ? url : url + "/";
}
Note, here I explicitly set other params to null. That is because of route reuse which MVC uses, but I didn't need at the moment.
Why not just adding this in your page?
<base href="~/">
This will be replaced when compiled by your URL path. I do that to make routing work for my Angular (2+) app and it works fine.

Unable to get property 'value' of undefined or null reference

I have registration form and button. OnClick - I call function on server side which make a validation of user's zip code at Database with Zipcodes. If validation passed successfully - user's data stored in Database (here I continue use server function). But if ZipCode does not match - I call Javascript function where I ask if user still wants to save his data to DB. and If yes - I save it using Ajax request. Problem is when I call Javascript function - firstly it should receive user's data on client side. But when reading data happens - I receive an error "Unable to get property 'value' of undefined or null reference". But user's data still exist at the form's fields. It seems that the data that read by the server from the form once - reset somewhere - and can not be read a second time on the client.
Here is my ASP Form
<body>
<form id="frmZipValidation" runat="server">
<div>
<asp:Label runat="server">Registration Form</asp:Label>
<asp:TextBox runat="server" ID="txtbxName"></asp:TextBox>
<asp:TextBox runat="server" ID="txtbxZipCode"></asp:TextBox>
<asp:DropDownList runat="server" ID="DDLCountry">
<asp:ListItem Text="Select country" Value="Select" Selected="True"></asp:ListItem>
<asp:ListItem Text="USA" Value="USA"></asp:ListItem>
<asp:ListItem Text="Canada" Value="Canada"></asp:ListItem>
</asp:DropDownList>
<asp:TextBox runat="server" ID="txtbxState"></asp:TextBox>
<asp:TextBox runat="server" ID="txtbxCity"></asp:TextBox>
<asp:Button runat="server" ID="btnSubmit" Text="Submit" OnClick="btnSubmit_Click"/>
</div>
</form>
</body>
Here is my Server Side
public partial class Default : System.Web.UI.Page
{
string Name;
string ZipCode;
string Country;
string State;
string City;
bool IsMatch;
Addresses dbAddresses = new Addresses();
User newUser;
protected void Page_Load(object sender, EventArgs e)
{
if (Request["Action"] != null && Request["Action"].Trim() != "")
{
if (Request["Action"] == "AddUser")
{
AddUser(Request["Name"], Request["ZipCode"], Request["Country"], Request["State"], Request["City"]);
}
}
}
private void AddUser(string UserName, string UserZip, string UserCountry, string UserState, string UserCity)
{
newUser = new User(UserName, UserZip, UserCountry, UserState, UserCity);
dbAddresses.Users.Add(newUser);
dbAddresses.SaveChanges();
}
protected void btnSubmit_Click(object sender, EventArgs e)
{
if (IsValid)
{
ZipCode = txtbxZipCode.Text;
Country = DDLCountry.Text;
State = txtbxState.Text;
City = txtbxCity.Text;
Name = txtbxName.Text;
IsMatch = false;
List<ZipCode> ZipC = (from z in dbAddresses.Zips
where z.Zip == ZipCode
select z).ToList();
//If ZipCode entered by client do not exists at Database return false
if (!ZipC.Any())
{
IsMatch = false;
}
else
{
for (int i = 0; i < ZipC.Count; i++)
{
if (ZipC[i].Country.ToString() == Country)
{
if (ZipC[i].State.ToString() == State)
{
if (ZipC[i].City.ToString() == City)
{
AddUser(Name, ZipCode, Country, State, City);
//Message to the user that all saved successfully
Page.ClientScript.RegisterClientScriptBlock(typeof(Page), "1", "<script>alert('Your data was saved successfully!');</script>");
IsMatch = true;
break;
}
else
{
IsMatch = false;
break;
}
}
else
{
IsMatch = false;
break;
}
}
else
{
IsMatch = false;
break;
}
}
}
//If user's data are not match, then go to JS client code where - If user wants in any case to save data - make it using AJAX request
if (!IsMatch)
{
string clientScript = "AjaxRequestSaveToDB();";
this.Page.ClientScript.RegisterStartupScript(this.GetType(), "MyClientScript", clientScript);
}
}
}
}
And here is Javascript:
function AjaxRequestSaveToDB()
{
var SaveData = confirm('Zip/Postal code doesn’t match region. Are you sure you want to save this data?');
if (SaveData)
{
var UserName = document.getElementById('txtbxName').value;
var UserZipCode = document.getElementById('txtbxZipCode').value;
var UserCountry = document.getElementById('DDLCountry').value;
var USerState = document.getElementById('txtbxState').value;
var UserCity = document.getElementById('txtbxCity').value;
SendDataToServer('AddUser', UserName, UserZipCode, UserCountry, USerState, UserCity);
alert("You data was saved successfully!");
}
else { alert('Not saved');
}
}
}
function SendDataToServer(RequestType, Name, ZipCode, Country, State, City)
{
var xmlHttp = getXmlHttp();
var Url = "Default.aspx?Action=" + escape(RequestType)
+ "&Name=" + escape(Name)
+ "&ZipCode=" + escape(ZipCode)
+ "&Country=" + escape(Country)
+ "&State=" + escape(State)
+ "&City=" + escape(City);
xmlHttp.open("GET", Url, true);
xmlHttp.send();
}
A short book about Client-Server Communications using "Custom" AJAX requests.
In ASP.net programming (almost) every time the client interacts with the server, the client sends all of its information to the server and then throws out its old content and replaces it with the response the client received from the server. So the problem you were running into is that your asp:button on the client machine was sending information to your .aspx page on the server and the server was interpreting the information, realizing something was wrong and telling the client it should ask the user for more information but throw out all the information that had been previously entered.
The best way that I have found to get around this problem is to use what I call "custom AJAX requests." Basically this means that we write a string of XML and send it to an ASP handler page which is set up to accept the XML string and do something with it. In my travels I have slimmed this down to basically 3 parts. The first is the user interface which contains all of the markup and CSS(and validation), the second is the JavaScript file that contains all of the data gathering and the actual AJAX request and lastly there is the ashx file that handles the request from the client.
So to start you will need to set up your user interface. Something along the lines of:
<body>
<form id="frmZipValidation" runat="server">
<div>
<div class="label">Registration Form<div>
<asp:TextBox ID="txtbxName" class="txtbxName" ClientIDMode="Static" runat="server"></asp:TextBox>
<asp:TextBox ID="txtbxZipCode" class="txtbxZipCode" ClientIDMode="Static" runat="server" ></asp:TextBox>
<asp:DropDownList ID="DDLCountry" class="DDLCountry" ClientIDMode="Static" runat="server" >
<asp:ListItem Text="Select country" Value="Select" Selected="True"></asp:ListItem>
<asp:ListItem Text="USA" Value="USA"></asp:ListItem>
<asp:ListItem Text="Canada" Value="Canada"></asp:ListItem>
</asp:DropDownList>
<asp:TextBox ID="txtbxState" class="txtbxState" ClientIDMode="Static" runat="server" ></asp:TextBox>
<asp:TextBox ID="txtbxCity" class="txtbxCity" ClientIDMode="Static" runat="server" ></asp:TextBox>
<input id="btnSubmit" class="btnSubmit" type="button" value="Save" onclick="SubmitForm()" />
</div>
</form>
</body>
Couple things to note with this:
The button to submit the form is NOT an ASP button but a HTML button.
All of the input controls are ASP controls but they have the ClientIDMode set to Static, this will only work in .NET 4.0 or higher.
We set the class to the same thing as the ID in case we aren't using .NET 4.0 or higher. Any CSS classes that you want to also add to the control can be added after the dummy ID class.(for my examples I'm assuming you are in .NET 4.0 but I can easily switch them to work without the ClientIDMode attribute if you need)
The second piece to the puzzle is the JavaScript. There are a couple ways that we can accomplish what we need. The first is by using vanilla JS without the help of any plugins or external libraries. This saves a very small amount of processing time, a marginal amount of loading time and can accomplish everything we ask of it. But, if we include an external library, JQuery, and plugin, JQuery Validation, then we can make our lives a whole heck of a lot easier during the programming phase by reducing the amount of code we have to write by a factor of about 10. And if we are really concerned about the load times then we can use the client cache to store the external libraries so that they only have to download them once. So whether or not you decide to use any external JavaScript libraries is up to what your project needs but since you are only concerned with validating that the zip code is not empty I will not use any JQuery but I just thought it would be worth mentioning because of how streamlined it makes the process.
Once you are ready to submit your form your first step will be to validate that the zipcode is valid. You can do this a couple ways depending on how in depth you want to get. The quickest check would just be to verify that the zip code text box is not empty when the button is clicked. So to do that we would just need to do:
function SubmitForm() { //This will be assigned as the click handler on your button in your HTML
if (document.getElementById('txtbxZipCode').value != null && document.getElementById('txtbxZipCode').value != '') {
Save('YourHandler', GetQueryString, GetXmlString, SuccessHandler, FailureHandler);
} else {
//Your user needs to know what went wrong...
}
}
So, down to the meat and potatoes of this whole situation. The AJAX request. I've come up with a reusable function that handles the entire AJAX request that looks like:
function Save(handlerName, GetQueryString, GetXmlString, SuccessHandler, FailureHandler) {
// Date.GetTime gets the number of milliseconds since 1 January 1970, so we divide by 1000 to get the seconds.
end = (new Date().getTime() / 1000) + 30;
//This variable is the actual AJAX request. This object works for IE8+ but if you want backwards compatability for earlier versions you will need a different object which I can dig up for you if you need.
var xmlhttp = new XMLHttpRequest();
//This is the function that fires everytime the status of the request changes.
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
//Get all the headers to determine whether or not the request was successful. This is a header you will need to add to the response manually.
var xx = xmlhttp.getResponseHeader("Success");
//the object xx will be a string that you designate. I chose to use True as the indicator that it was successful because it was intuitive.
var x1 = xx.trim();
if (x1 != undefined && x1 == 'True' && (new Date().getTime() / 1000) < end) {
//If the response was successful and the timeout hasn't elapsed then we get the XML from the response and call the success handler
var xmlResponse = xmlhttp.responseXML;
SuccessHandler(sender, xmlResponse);
} else if ((new Date().getTime() / 1000) < end) {
//If the response was not successful and the timeout hasn't elapsed then we get the XML from the response and call the failure handler
var xmlResponse = xmlhttp.responseXML;
FailureHandler(sender, xmlResponse);
} //If the request was successful
} //If the readystate is 4 and the status is 200
} //OnReadyStateChanged function
//This gets the query string to be added to the url
var varString = GetQueryString();
//Build XML string to send to the server
var xmlString = GetXmlString();
//Open the request using the handler name passed in and the querystring we got from the function passed in
xmlhttp.open("POST", "../RequestHandlers/" + handlerName + ".ashx" + varString, true);
//This tells the handler that the content of the request is XML
xmlhttp.setRequestHeader("Content-Type", "text/xml");
//Send the request using the XML we got from the other function passed in.
xmlhttp.send(xmlString);
}
This function has a built in timeout which makes it so that if the server takes more than 30 seconds to respond to a request then any response that the client receives is ignored. For my implementations this is combined with another function that displays something to the user to tell them that the website is working on their request and if the time out elapses it tells them that a time out occurred.
The second thing this function does is it assumes that all handlers will be in a folder next to the root of your website named RequestHandlers. I use this set up just to consolidate all of my handler files but you can really change where it is looking to wherever you want.
The function itself takes in a string and four function pointers. The string represents the name of the handler that will be waiting to interpret the request, the four function pointers all have very specific jobs.
The first function pointer is GetQueryString this represents a function you will have to write that will append any variables that you deem necessary to the end of the URL being posted back to. This site gives a pretty accurate explanation of what the query string should be used for. For me a common GetQueryString function looks something like:
function GetPaymentQueryString() {
var varString = '';
varString = "?CCPayment=True";
return varString;
}
The second function pointer, GetXMLString, is used to create the XML string(go figure...) that will be sent to the handler page that we are posting back to. This string will represent the bulk of the request. Everything that should not be shown to anyone snooping your requests should be sent as an XML string, if you are really paranoid you can send it as an encrypted XML string but that's not, strictly speaking, necessary. It all depends on what you are sending, if its complete credit card information then, yeah, maybe you would want to consider it, but if its first and last names then encrypting it would be overkill.
A common GetXMLString function might look like:
function GetPaymentXmlString() {
var xmlString = '';
xmlString = '<?xml version="1.0" encoding="UTF-8"?><Address><ZipCode>' + document.getElementById('txtbxZipCode').value + '</ZipCode></Address>';
return xmlString;
}
The important part of that function is to get your XML right. The first tag is pretty universal and should be fine to use in most situations and then after that its all just matching the tags up. I left out a lot of your fields to save space.
The last two function pointers are what you will want to call if everything goes as planned and if something fails respectively. The way that I normally handle successful requests is to hide the inputs as a whole(usually by putting them inside of their own div section) and displaying a confirmation message of some sort. Failed requests can be a bit trickier because you have to tell the user why they failed. The way that I do that is by having a dummy div section above everything else on the page with some sort of special CSS attached to it that makes the div stand out in some way and if the request fails then I send a string of text from the server with my best guess of why it failed and assign it to the be displayed in the div section. How you decide to display the results to the user is obviously all dictated by the project itself. Since what you do when it succeeds or fails is basically on a project by project basis I can't really give a good generic example of what you should do so for this part you are on your own.
Now that we have those pieces in place, the last piece to make is the handler.
Basically for all intents and purposes a handler is basically an ASPX webpage with nothing on it. So the HTML that makes up your handler pages, which have the extension .ashx, will look like:
<%# WebHandler Language="VB" CodeBehind="YourHandler.ashx.cs" Class="YourHandler" %>
And that's it. There should be no other markup in your actual .ashx file. Obviously the name of the handler will change depending on what you are doing.
The code behind when creating an ashx file by default will be a class that contains a single function named ProcessRequest. Basically you can treat this function as a sort of "request received" event. So in your case you would move the content of your btnSubmit_Click function to the ProcessRequest function in the ashx file. You can add any properties or other functions that you want but the ProcessRequest function must be present for the handler to work as far as I know.
One extra step that you will need to do is to get the information from the XML that was sent to your handler and also tell the response that you will be sending XML back to the client.
So to get the XML from the request you will need to do:
IO.StreamReader textReader = New IO.StreamReader(context.Request.InputStream);
context.Request.InputStream.Seek(0, IO.SeekOrigin.Begin);
textReader.DiscardBufferedData();
XDocument xml = XDocument.Load(textReader);
String zip = xml.Elements("Address").Elements("ZipCode").FirstOrDefault().Value;
In order to send XML back to the client you will need to add a couple headers to the response and you accomplish that by adding(I think this is the correct way to implement an interface in C# not positive on this point though):
class YourHandler : System.Web.IHttpHandler, System.Web.SessionState.IReadOnlySessionState
under your class definition and:
context.Response.ContentType = "text/xml";
context.Response.ContentEncoding = System.Text.Encoding.UTF8;
context.Response.Cache.SetCacheability(HttpCacheability.NoCache);
context.Response.Cache.SetAllowResponseInBrowserHistory(True);
to the beginning of your ProcessRequest function. Those six lines tell the client it will be receiving XML and not to cache any of the response which will ensure that your clients always see the most up-to-date content.
So. There it is. You should now have the framework to validate user input, create an AJAX request, send the request to a custom handler, accept XML from the client, write XML to the client and display the res-...I knew I forgot something...
What is the client supposed to do with the XML it gets from the server? throw it at the wall and see what sticks? No that won't work. You'll need a way to interpret the XML on the client side. Luckily the XMLHttpRequest object has been written to make this task a lot easier than it sounds.
You may have noticed that I set up my success and failure handlers to take a sender object and an XML object. The sender is really overkill and can be ignored(or removed) for this example to work fine. The XML object is what we are concerned with for now. Before we even get into the client side I must mention that you will have to go through the same process on the server side as you did on the client side and manually write your XML string including all the values you want the client to know about. For this example I'm going to assume you want to display a FriendlyMessage to the user. To write the response to the client you will do something like:
using (System.Xml.XmlTextWriter writer = new System.Xml.XmlTextWriter(context.Response.Output)) {
context.Response.AddHeader("Success", true);
System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
doc.LoadXml("<?xml version='1.0' encoding='UTF-8'?><Response><FriendlyMessage>" + Message + "</FriendlyMessage></Response>");
doc.WriteTo(writer);
writer.Flush();
writer.Close();
}
On the client side to get the FriendlyMessage from the XML you will need to do:
xml.getElementsByTagName("FriendlyMessage")[0].childNodes[0].nodeValue
Now this line makes a few assumptions. Like, you may want to add some checks in to make sure xml.getElementsByTagName("FriendlyMessage") actually has children before trying to evaluate them. Those sorts of checks are up to your discretion.
This time I think I've actually covered all the steps. I hope my "little" guide helps you and I didn't bore you too much. I apologize for the length but its sort of a process so getting it right takes a few steps. Once you get the base line in place and working it really lends itself to any situation. This layout also makes your user experience much better than having them wait for full trips to the server each time.
I sincerely hope this helps you get your project done and that I haven't skipped a step or something equally as embarrassing...

How do I get Url.Action to use the right port number?

I'm creating a website using MVC3, I'm using the razor syntax to create the views and it's all running under azure.
Currently I'm running under the azure emulator locally.
I have a view at the url: 'http://localhost:81/Blah/Foo'.
In that view I want to get the Url for another action.
To achieve this I use: Url.Action("SomeAction", "SomeController", null, this.Request.Url.Scheme)
However because of the load balancing the azure emulator does the port number the request is made on changes.
i.e. whilst it's running on port 81, the request might come from port 82.
This leads to to create an incorrect url 'http://localhost:82/Blah/Bar' and I get a 400, bad hostname error.
Following the info in this post http://social.msdn.microsoft.com/Forums/en-US/windowsazure/thread/9142db8d-0f85-47a2-91f7-418bb5a0c675/ I found that I could get the correct host and port number using HttpContext.Request.Headers["Host"].
But I can only pass a host-name to Url.Action, if I try passing the host-name and port then it still appends what it thinks is the right port so I end up with localhost:81:82.
EDIT: I found someone with the same problem. They seem to have gathered the same information I have (except they've included a reproduction too) but they don't have a useful fix as I can't specify the port number manually.
http://social.msdn.microsoft.com/Forums/en-US/windowsazuredevelopment/thread/87c729e8-094c-4578-b9d1-9c8ff7311577/
I suppose one fix would be to make my own Url.Action overload that lets me specify the port.
For everyone coming here who actually NEEDS an absolute path and are behind a load balanced system, here's what I came up with:
//http://stackoverflow.com/questions/126242/how-do-i-turn-a-relative-url-into-a-full-url
public static string AbsoluteAction(this UrlHelper url, string actionName, string controllerName, object routeValues = null)
{
Uri publicFacingUrl = GetPublicFacingUrl(url.RequestContext.HttpContext.Request, url.RequestContext.HttpContext.Request.ServerVariables);
string relAction = url.Action(actionName, controllerName, routeValues);
//this will always have a / in front of it.
var newPort = publicFacingUrl.Port == 80 || publicFacingUrl.Port == 443 ? "" : ":"+publicFacingUrl.Port.ToString();
return publicFacingUrl.Scheme + Uri.SchemeDelimiter + publicFacingUrl.Host + newPort + relAction;
}
And then, from https://github.com/aarnott/dotnetopenid/blob/v3.4/src/DotNetOpenAuth/Messaging/HttpRequestInfo.cs via http://go4answers.webhost4life.com/Example/azure-messing-port-numbers-creates-28516.aspx
/// <summary>
/// Gets the public facing URL for the given incoming HTTP request.
/// </summary>
/// <param name="request">The request.</param>
/// <param name="serverVariables">The server variables to consider part of the request.</param>
/// <returns>
/// The URI that the outside world used to create this request.
/// </returns>
/// <remarks>
/// Although the <paramref name="serverVariables"/> value can be obtained from
/// <see cref="HttpRequest.ServerVariables"/>, it's useful to be able to pass them
/// in so we can simulate injected values from our unit tests since the actual property
/// is a read-only kind of <see cref="NameValueCollection"/>.
/// </remarks>
internal static Uri GetPublicFacingUrl(HttpRequestBase request, NameValueCollection serverVariables)
{
//Contract.Requires<ArgumentNullException>(request != null);
//Contract.Requires<ArgumentNullException>(serverVariables != null);
// Due to URL rewriting, cloud computing (i.e. Azure)
// and web farms, etc., we have to be VERY careful about what
// we consider the incoming URL. We want to see the URL as it would
// appear on the public-facing side of the hosting web site.
// HttpRequest.Url gives us the internal URL in a cloud environment,
// So we use a variable that (at least from what I can tell) gives us
// the public URL:
if (serverVariables["HTTP_HOST"] != null)
{
//ErrorUtilities.VerifySupported(request.Url.Scheme == Uri.UriSchemeHttps || request.Url.Scheme == Uri.UriSchemeHttp, "Only HTTP and HTTPS are supported protocols.");
string scheme = serverVariables["HTTP_X_FORWARDED_PROTO"] ?? request.Url.Scheme;
Uri hostAndPort = new Uri(scheme + Uri.SchemeDelimiter + serverVariables["HTTP_HOST"]);
UriBuilder publicRequestUri = new UriBuilder(request.Url);
publicRequestUri.Scheme = scheme;
publicRequestUri.Host = hostAndPort.Host;
publicRequestUri.Port = hostAndPort.Port; // CC missing Uri.Port contract that's on UriBuilder.Port
return publicRequestUri.Uri;
}
// Failover to the method that works for non-web farm enviroments.
// We use Request.Url for the full path to the server, and modify it
// with Request.RawUrl to capture both the cookieless session "directory" if it exists
// and the original path in case URL rewriting is going on. We don't want to be
// fooled by URL rewriting because we're comparing the actual URL with what's in
// the return_to parameter in some cases.
// Response.ApplyAppPathModifier(builder.Path) would have worked for the cookieless
// session, but not the URL rewriting problem.
return new Uri(request.Url, request.RawUrl);
}
What happens if you just use Url.Action("Action", "Controller")? That should just generate a relative URL, which should work.
(Or perhaps a better question is: why aren't you using that overload?)
I found this worked for me...
var request = HttpContext.Request;
string url = request.Url.Scheme + "://" +
request.UserHostAddress + ":" +
request.Url.Port;

Spoofing HTTP Referrer data using ASP.NET

Answers on here and various other sites are often full of warnings not to trust HTTP Referrer headers because they are 'so easily' spoofed or faked.
Before I go any further - no, I'm not up to no good - but I do want to run some referrer-dependant tests.
Whilst I don't doubt that the warnings about fake referrers are true, I can't really find much detailed info on how they can be manipulated. Even the Wikipedia article only talks about it in general terms.
I'm about to play with the RefControl addin for FireFox.
Programatically (in ASP.NET specifically) the UrlReferrer is a read-only property, so I don't see how I can fire off requests with fake referrer data if I can't set it? Do I really have to do it manually?
How would I use ASP.NET to send a request to my site with a user-supplied variable to populate the referrer header?
EDIT : As per my comment below, I ideally want to take an incoming request, manupulate the referrer data and then pass the request on to another page, intact. If I can make it appear intact by building a new one from scratch and copying the original properties, then that is fine too.
I don't know if this exactly what you want, but in general, you should be able to spoof the value of the UrlReferer property (even if it's read-only) in HttpContext.Current.Request by using a bit of reflection.
For example:
FieldInfo fi = HttpContext.Current.Request.GetType().GetField("_referrer", BindingFlags.NonPublic | BindingFlags.Instance);
string initialReferer = HttpContext.Current.Request.UrlReferrer.ToString();
if (fi != null)
fi.SetValue(HttpContext.Current.Request, new Uri("http://example.com"));
string fakedReferer = HttpContext.Current.Request.UrlReferrer.ToString();
On VS; these are the values before and after changing the UrlReferrer:
initialReferer
"http://localhost/Test/Default.aspx"
fakedReferer
"http://example.com/"
If you open the System.Web assembly using ILSpy you'll notice that the UrlReferrer property looks something like this:
public Uri UrlReferrer
{
get
{
if (this._referrer == null && this._wr != null)
{
string knownRequestHeader = this._wr.GetKnownRequestHeader(36);
if (!string.IsNullOrEmpty(knownRequestHeader))
{
try
{
if (knownRequestHeader.IndexOf("://", StringComparison.Ordinal) >= 0)
{
this._referrer = new Uri(knownRequestHeader);
}
else
{
this._referrer = new Uri(this.Url, knownRequestHeader);
}
}
catch (HttpException)
{
this._referrer = null;
}
}
}
return this._referrer;
}
}
This likely isn't going to get you what you want. But you can edit the Referror of an HttpWebRequest. I don't think there is a way of editing the referrer of your request in context.
using System.Net;
HttpWebRequest Req= (HttpWebRequest)System.Net.HttpWebRequest.Create("http://somewhere.com/");
Req.Referer = "http://www.fakesite.com";

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