I'm fairly new to ASP.NET. And I was wondering how I could go about getting xml from a site (Kuler's API in this case), and then post the result using AJAX?
So what I want here, is to be able to do a query to Kuler's API. The URL would be something like "http://kuler-api.adobe.com/rss/search.cfm?query="+queryVariable
Then send the resulting xml back to JS in some way.
Any pointers would be appreciated (:
What you'll need to do is have a handler that will perform the request for the XML and send it back to the browser using AJAX. It will act as an intermediary between server and client, and you won't have to worry about cross-domain policies.
This is what I do on one of my sites. I have a handler (let's call it proxy.ashx) that I call from a jQuery AJAX request. The proxy.ashx simply performs a WebClient.DownloadString action on the remote URL and sends the remote response (the XML) back to the client-side.
I think that Tim said enough, but what I would like to add is how you could do the server side request:
XmlDocument doc = new XmlDocument();
HttpWebRequest r = (HttpWebRequest)HttpWebRequest.Create("http://kuler-api.adobe.com/rss/search.cfm?query="+queryVariable);
r.Method = "POST";
using (Stream writeStream = r.GetRequestStream())
{
UTF8Encoding encoding = new UTF8Encoding();
byte[] bytes = encoding.GetBytes(bodyRequest);
writeStream.Write(bytes, 0, bytes.Length);
}
try
{
using (HttpWebResponse response = (HttpWebResponse)r.GetResponse())
{
using (Stream responseStream = response.GetResponseStream())
{
using (StreamReader readStream = new StreamReader(responseStream, Encoding.UTF8))
{
doc.Load(readStream);
}
}
}
}
catch (WebException ex)
{
//Handle exception
}
I'd do the whole thing in Javascript using Jquery's ajax library, if possible. It's very simple to use and you don't have to worry about getting the XML from server to client that way.
Write a .net webservice (.asmx) that encapsulate the cross domain call, then call that service with AJAX.
Related
I generate request to a certain API which is mentioned here for sending an sms http://help.voxeo.com/go/help/evolution.sms.postapi
The request generates an XML response as follow
<rsp stat="ok">
<success msg="accepted" transactionid="2e47fe224d25559a696a7bdddec1828b" messageid="cf0d21f067e5b386a2e042134687eb5c"/>
</rsp>
I want to read if rsp stat in response is ok or fail how can i do it .
These are the first two lines how can i get particular xml tag out of response stream
HttpWebResponse response = (HttpWebResponse)myReq.GetResponse();
Stream content = response.GetResponseStream();
Why not use XmlDocument to parse the XML. For example,
using(var reader = new StreamReader(content))
{
var doc = new XmlDocument();
doc.LoadXml(reader.ReadToEnd());
// you may want to compare case in-sensitive
if (doc.DocumentElement.Attributes["stat"].Value == "ok")
{
// success
}
}
(There is also Load method that would load from stream directly but I am not sure if it expects xml declaration at the beginning or not)
Yet another alternative is using XmlReader in case response could be lengthy and you wants to parse the initial bits as soon as its available.
try to read with XmlTextReader (http://msdn.microsoft.com/en-us/library/system.xml.xmltextreader%28v=vs.71%29.aspx)
I need to upload a file to my server. I have no prior knowledge to server side programming and need some advice I can understand. I have my file (JPEG Image) in a byte array in my Windows Phone app. I now need to upload it to my server. I currently have a sample that uses HttpWebRequest with post, but I do not know how to handle the data in that post from the asp page. If you could explain how to do this it would be great, but I am open to any alternatives, providing they can be used with Windows Server.
The code I am currently using: ('b' is the byte array for the file)
var uri = "http://www.masonbogert.info/mcode/default.aspx";
var request = HttpWebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "image/jpeg"; // Change to whatever you're uploading.
request.BeginGetRequestStream((result1) =>
{
using (Stream stream = request.EndGetRequestStream(result1))
{
stream.Write(b, 0, b.Length);
}
request.BeginGetResponse((result2) =>
{
var response = request.EndGetResponse(result2);
// Optionally handle the response.
var responseStream = response.GetResponseStream();
Dispatcher.BeginInvoke(new readstreamdelegate(readstream), responseStream);
}, null);
}, null);
Remember, when it comes to ASP and any other server side programming I have no prior knowledge, so please explain!
You can try to use the "WebClient" class for getting it. More information you can get there: "http://msdn.microsoft.com/en-us/library/system.net.webclient(v=vs.80).aspx".
Please see this page: http://nediml.wordpress.com/2012/05/10/uploading-files-to-remote-server-with-multiple-parameters/#more-234
I have given
[WebGet(UriTemplate = "/{year}/{issue}/{article}")]
Article GetArticle(string year, string issue, string article);
[OperationContract]
[WebInvoke(UriTemplate = "/{year}/{issue}",Method="POST")]
Article AddArticle(string year, string issue, Article article);
My URL is http://localhost:1355/Issues.svc/
if I give this I am fetching all data from the database
http://localhost:1355/Issues.svc/2010/June/A
GetArticle method fires for the filtered data to bring from db.
Similarly I have to call the Add Article(WebInvoke) method to insert data in to the database.
How should I call this method in the browser
how my url should be should I give method=post
check this post help you to achieve the task you want :Create REST service with WCF and Consume using jQuery
You won't be able to send an HTTP post from a browser by just modifying the URL. You'll have to have a web page with a HTML form, some Javascript code, some server-side code, or something else that has the ability to make an HTTP POST request to your service URL.
If you are just wanting to test your service while in development, here's a good HTTP debugging tool that you might want to check out: http://fiddler2.com
You can't use post it using browser url.
Try this code
//Creating the Web Request.
HttpWebRequest httpWebRequest = HttpWebRequest.Create("http://localhost/DemoApp/Default.aspx") as HttpWebRequest;
//Specifing the Method
httpWebRequest.Method = "POST";
//Data to Post to the Page, itis key value pairs; separated by "&"
string data = "Username=username&password=password";
//Setting the content type, it is required, otherwise it will not work.
httpWebRequest.ContentType = "application/x-www-form-urlencoded";
//Getting the request stream and writing the post data
using (StreamWriter sw = new StreamWriter(httpWebRequest.GetRequestStream()))
{
sw.Write(data);
}
//Getting the Respose and reading the result.
HttpWebResponse httpWebResponse = httpWebRequest.GetResponse() as HttpWebResponse;
using (StreamReader sr = new StreamReader(httpWebResponse.GetResponseStream()))
{
MessageBox.Show(sr.ReadToEnd());
}
Source : http://www.dotnetthoughts.net/2009/11/10/post-data-using-httpwebrequest-in-c-sharp/
I have a web service sitting on a dev machine written in python. I am trying to access said webservice using asp.net via the server side. the webservice has been tested and works in every other instance. but when I hit it via asp.net using a post method asp.net doesn't seem to be sending the post values to the webservice at all, everything else is sent fine. If I run the exact same code in a console application everything works 100%.
using System;
using System.IO;
using System.Net;
using System.Web;
using System.Text;
class WebService {
static public String GetContent(String user_id, String content_id) {
Uri address = new Uri("http://url.to.api/");
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(address);
String response_text = String.Empty;
// Set type to POST
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.Credentials = new NetworkCredential("username", "password");
string data = string.Format("userid={0}&contentid={1}", user_id, content_id);
byte[] byteData = UTF8Encoding.UTF8.GetBytes(data.ToString());
request.ContentLength = byteData.Length;
using (Stream postStream = request.GetRequestStream()) {
postStream.Write(byteData, 0, byteData.Length);
}
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse()) {
StreamReader reader = new StreamReader(response.GetResponseStream());
response_text = reader.ReadToEnd();
}
return response_text;
}
}
updated * with the class more or less thats being used. "url, user/pass".
Also we have checked the information going back and fourth and the webservice never sees the post data... this code as is ran on both a console app and in a asp.net project both hit the webservice, both get a response. the console gets a response with valid information showing that its working, the asp.net project runs and receives and error stating that userid isn't being passed. We have dozens of other sites hitting this webservice with no issues, except non are written in asp.net.
Use a proxy such as Fiddler to view the HTTP transaction between your app and the web service. That should give you a better idea of which end the error is on, and its nature.
You may consider running this against a test "Hello World" service just to test communcations.
Also, post your real code. Change the uri if you want, but what you've quoted above won't compile. The problem may be outside of this snippet.
update
How long is it taking for you to receive a reply? Timeout? Running out of connections?
Our Situation:
Our team needs to retrieve log information from a 3rd party website (Specifically, this log
information is call logs -- our client rents an 866 number. When calls come in, they assist
people and need to make notes accordingly in our application that will correspond with the
current call). Our client has a web account with the 3rd party that allows them to view the
current call logs (date/time, phone number, amount of time on each call, etc).
I contacted the developer of their website and inquired about API or any other means of syncing
our database with their constantly updating database. They currently DO NOT support API. I
informed them of my situation and they are perfectly fine with any way we can retrieve the
information (bot/crawler). *The 3rd party said that they are working on API but could not give
us a general timeline as to when it will be up... and as with every client, they need to start
production ASAP.
I completely understand that if the 3rd party were to change their HTML layout, it may cause a
slight headache for us (sorting the data from the webpage). That being said, this is a temporary
solution to a long term issue. Once they implement their API, we will switch them over to it.
So my question is this:
What is the best way to log into the 3rd party website (see image: http://i903.photobucket.com/albums/ac239/jreedinc/customtf.jpg)
and retrieve certain HTML pages? We have reviewed source codes of webcrawlers, but none of them
have the capability of storing cookies and posting information back to the website (with log in information). We would prefer to do this in ASP.NET.
Is there another way to accomplish logging on to the website, then retrieving said information?
The classes you'll need to use are in the System.Net namespace. Below is some quick and dirty proof of concept code. To login in to a site that uses form login + cookies for security and then scrape the HTML output of a page.
In order to parse the HTML results you'll need to use an additional tool.
Possible HTML parsing tools.
SgmlReader, can convert HTML to XML. You then use .NET's XML features to extract data from the XML.
http://code.msdn.microsoft.com/SgmlReader
HTML Agility Pack, allows XPath queries against HTML documents.
http://htmlagilitypack.codeplex.com/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
class WebWorker {
/// <summary>
/// Cookies for use by web worker
/// </summary>
private System.Collections.Generic.List `<System.Net.Cookie` > cookies = new List < System.Net.Cookie > ();
public string GetWebPageContent(string url) {
System.Net.HttpWebRequest request = (System.Net.HttpWebRequest) System.Net.WebRequest.Create(url);
System.Net.CookieContainer cookieContainer = new System.Net.CookieContainer();
request.CookieContainer = cookieContainer;
request.Method = "GET";
//add cookies to maintain session state
foreach(System.Net.Cookie c in this.cookies) {
cookieContainer.Add(c);
}
System.Net.HttpWebResponse response = request.GetResponse() as System.Net.HttpWebResponse;
System.IO.Stream responseStream = response.GetResponseStream();
System.IO.StreamReader sReader = new System.IO.StreamReader(responseStream);
System.Diagnostics.Debug.WriteLine("Content:\n" + sReader.ReadToEnd());
return sReader.ReadToEnd();
}
public string Login(string url, string userIdFormFieldName, string userIdValue, string passwordFormFieldName, string passwordValue) {
System.Net.HttpWebRequest request = (System.Net.HttpWebRequest) System.Net.WebRequest.Create(url);
System.Net.CookieContainer cookieContainer = new System.Net.CookieContainer();
request.CookieContainer = cookieContainer;
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
string postData = System.Web.HttpUtility.UrlEncode(userIdFormFieldName) + "=" + System.Web.HttpUtility.UrlEncode(userIdValue) +
"&" + System.Web.HttpUtility.UrlEncode(passwordFormFieldName) + "=" + System.Web.HttpUtility.UrlEncode(passwordValue);
request.ContentLength = postData.Length;
request.AllowAutoRedirect = false; //allowing redirect seems to loose cookies
byte[] postDataBytes = System.Text.Encoding.UTF8.GetBytes(postData);
System.IO.Stream requestStream = request.GetRequestStream();
requestStream.Write(postDataBytes, 0, postDataBytes.Length);
System.Net.HttpWebResponse response = request.GetResponse() as System.Net.HttpWebResponse;
// System.Diagnostics.Debug.Write(WriteLine(new StreamReader(response.GetResponseStream()).ReadToEnd());
System.IO.Stream responseStream = response.GetResponseStream();
System.IO.StreamReader sReader = new System.IO.StreamReader(responseStream);
System.Diagnostics.Debug.WriteLine("Content:\n" + sReader.ReadToEnd());
this.cookies.Clear();
if (response.Cookies.Count > 0) {
for (int i = 0; i < response.Cookies.Count; i++) {
this.cookies.Add(response.Cookies[i]);
}
}
return "OK";
}
} //end class
//sample to use class
WebWorker worker = new WebWorker();
worker.Login("http://localhost/test/default.aspx", "uid", "bob", "pwd", "secret");
worker.GetWebPageContent("http://localhost/test/default.aspx");
I used a tool recently called WebQL (its a web scraper tool that lets the developer use SQL like syntax to scrape information from web pages.
WebQL on Wikipedia
This is actually a relatively simple operation. What you need to do is get the page that the screenshot posts back to (something like login.php, etc) and then construct a webrequest to that page with the login data you have. You will most likely get back a cookiecontainer that will have your login cookie to use on all subsequent requests.
You can look at this MSDN article for the basics of how to do it, but their write-up is kind of confusing. Look at the community comments at the end for an example of how to post back page variables (like the username and password). You will need to make sure you pass the cookiecontainer around on subsequent requests.
Unfortunately .NET does not natively have something like WWW::Mechanize, but the Webclient does have an "upload value" which might make it easier. You will still have to manually parse the page to figure out what fields you need to pass.