I'm looking for a code fragment that will show me how to get an SID for Google Reader in C#. Anyone know of such a beast?
It's quite easy. First you should perform a GET request to https://www.google.com/accounts/ClientLogin page with your login and password (don't forget to url encode them). And then just parse response (there will be several parameters divided by a new line character \n) to get SID. Here is a simplest example (no error handling):
var url = string.Format("https://www.google.com/accounts/ClientLogin?service=reader&Email={0}&Passwd={1}",
HttpUtility.UrlEncode(email),
HttpUtility.UrlEncode(password)
);
var web = new WebClient();
web.DownloadStringCompleted += (sender, e) =>
{
var sid = e.Result.Split('\n')
.First(s => s.StartsWith("SID="))
.Substring(4);
};
web.DownloadStringAsync(new Uri(url));
But you could make this code more elegant by using AsyncCTP.
You will have to deal with manual HTTP manipulations and cookies for this. A pretty decent explanation is available on this page. If you worked with HTTP requests in C#, it shouldn't be a problem to pick up the methods described there.
Related
I am currently working on a OAuth2 implementation. However I am stuck on an Error 401. It seems like there is something wrong with my post request that is supposed to retrieve the access token from the Company the User logged in to. This is my code:
internal void RequestAccessToken(string code)
{
string requestBody = "grant_type="+ WebUtility.UrlEncode(GRANTTYPE)+ "&code=" + WebUtility.UrlEncode(code)+"&redirect_uri="+ WebUtility.UrlEncode(REDIRECT_URI);
WebClient client = new WebClient();
client.Headers.Add("Authorization",HeaderBase64Encode(CLIENT_ID, SECRETKEY));
var response = client.UploadString("https://thewebsiteiamcallingto.com/some/api", requestBody);
var responseString = client.OpenRead("https://thewebsiteiamcallingto.com/some/api");
}
My Questions are:
Is there anything wrong with the way I try to make the POST request ?
Is there a way to retrieve the whole string that is posted to the URI using UploadString?
P.S. I have seen this post regarding the POST creation. However I find the async part to be too complicated for my case.
Since we dont know the api documentation, I would suggest you to make a postman request and view the actual request sent and response received, and secondly make a request using your method and capture using a utility like wireshark and compare the difference.
I'm trying to send special characters through an http request, now I'm using Loopj as my http client. The problem is that when I try to send special characters i.e. "áéíóú" the request goes out with the characters "·ÈÌÛ˙", this is causing some issues on the server sider.
I've gone through the Loopj code and couldn't find anything relative to recoding my string or anything like it. In the worst case it seems like it would be encoded in UTF-8 which actually supports this characters.
Hope anyone can help.
Best Regards.
I am guessing you mean AsyncHttpClient library, correct?
AHC defaults to encoding all I/O in UTF-8. Due to the lack of source code, I would point you to investigate the following:
What is the encoding of the input? Make sure it's in UTF-8.
Are you running the input through a filter/function that might change its encoding? Make sure that the filter/function produces UTF-8 also.
Prior to checking what your backend actually receives, change your client to submit to http://httpbin.org/post and then check the result.
If you receive correct submission in httpbin, and bad submission in your backend, the problem is NOT in AHC but in your backend.
If you receive bad submissions in both httpbin and the backend, then the data being sent was originally bad or in a wrong encoding.
I hope this helps you find the problem quickly.
Why Don't you use this Approach:
HttpParams httpParameters = new BasicHttpParams();
HttpProtocolParams.setContentCharset(httpParameters, HTTP.UTF_8);
HttpProtocolParams.setHttpElementCharset(httpParameters, HTTP.UTF_8);
HttpClient client = new DefaultHttpClient(httpParameters);
client.getParams().setParameter("http.protocol.version", HttpVersion.HTTP_1_1);
client.getParams().setParameter("http.socket.timeout", new Integer(2000));
client.getParams().setParameter("http.protocol.content-charset", HTTP.UTF_8);
httpParameters.setBooleanParameter("http.protocol.expect-continue", false);
HttpPost request = new HttpPost("http://www.server.com/some_script.php?sid=" + String.valueOf(Math.random()));
request.getParams().setParameter("http.socket.timeout", new Integer(5000));
List<NameValuePair> postParameters = new ArrayList<NameValuePair>();
// you get this later in php with $_POST['value_name']
postParameters.add(new BasicNameValuePair("value_name", "value_val"));
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(postParameters, HTTP.UTF_8);
request.setEntity(formEntity);
HttpResponse response = client.execute(request);
in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuffer sb = new StringBuffer("");
String line = "";
String lineSeparator = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line);
sb.append(lineSeparator);
}
in.close();
String result = sb.toString();
Users of above code says, this code works like charm. And i think if you are facing issues with your approach then you should change your approach to solve your problem.
See this Link which i found useful for you: Android default charset when sending http post/put - Problems with special characters
I am trying to call google maps geocode and am following the example on their webpage to try and apply it to mine
http://code.google.com/apis/maps/documentation/geocoding/index.html
in this example, the Geocoding API requests an xml response for the
identical query shown above for "1600 Amphitheatre Parkway, Mountain
View, CA":
http://maps.googleapis.com/maps/api/geocode/xml?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=true_or_false
The XML returned by this request is shown below.
Now i am trying to run that url like this in my c# winforms application
string url = "http://maps.googleapis.com/maps/api/geocode/xml?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=true_or_false";
WebRequest req = HttpWebRequest.Create(url);
WebResponse res = req.GetResponse();
StreamReader sr = new StreamReader(res.GetResponseStream());
try
{
Match coord = Regex.Match(sr.ReadToEnd(), "<coordinates>.*</coordinates>");
var b = coord.Value.Substring(13, coord.Length - 27);
}
finally
{
sr.Close();
}
However it doesnt seem to be returning anything and as such my var b line gives an index out of bounds error. Can anyone point me in the right direction for at least getting the example to work so i can apply the logic to my own application?
Thanks
If you visit your link "http://maps.googleapis.com/maps/api/geocode/xml?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=true_or_false" directly in a browser you can see what it's returning. It's giving me a REQUEST DENIED error.
The problem is caused by the sensor=true_or_false parameter. You have to choose if you want it to be true or false. Google put it this way in their example so that you have to explicitly decide for yourself. This setting indicates if your application is using a location sensor or not. In your case, I'm guessing not, so set it to false.
If you change the link you're using to http://maps.googleapis.com/maps/api/geocode/xml?address=1600%20Amphitheatre%20Parkway,%20Mountain%20View,%20CA&sensor=false, I think you'll get the results you were expecting.
I am trying to post to google so I can log into Google Reader and download subscription list, but I am unable to find a way to post to google in the windows 7 phone sdk, does anyone have an example on how to do this?
*Edit: Sorry wasn't very clear I am trying use the POST method, to submit an email and password to google login and retrieve a sid. I have used WebClient and HttpWebRequest but all the examples I have seen to send post data, the api calls are not in the windows 7 phone sdk.
I don't know anything about the Google API you're trying to use, but if all you need is to send a POST request, you can certainly do that with WebClient or HttpWebRequest. With WebClient, you can use either WebClient.OpenWriteAsync() or WebClient.UploadStringAsync(), the documentation is here: http://msdn.microsoft.com/en-us/library/tt0f69eh%28v=VS.95%29.aspx
With HttpWebRequest, you'll need to set the Method property to "POST". Here's a basic example:
var request = WebRequest.Create(new Uri(/* your_google_url */)) as HttpWebRequest;
request.Method = "POST";
request.BeginGetRequestStream(ar =>
{
var requestStream = request.EndGetRequestStream(ar);
using (var sw = new StreamWriter(requestStream))
{
// Write the body of your request here
}
request.BeginGetResponse(a =>
{
var response = request.EndGetResponse(a);
var responseStream = response.GetResponseStream();
using (var sr = new StreamReader(responseStream))
{
// Parse the response message here
}
}, null);
}, null);
The WebClient class may be easier to use, but is less customizable. For instance, I haven't seen a way to be able to attach cookies to WebClient requests, or a way to set the Content-Type header when using WebClient.
Have you tried using RESTSharp for your Windows Phone 7 project? The latest release supports Windows Phone 7 and I have had no issues working with popular REST APIs with it. In your particular case where you are trying to use the Google Reader API, this article by Luke Lowry can possibly help.
Not sure what you've already used, but have you tried WebClient?
WebClient web = new WebClient();
web.DownloadStringCompleted += (s, e) =>
{
if (e.Error == null)
CodeHereToHandleSuccess();
else
CodeHereToHandleError(e.Error);
};
web.DownloadStringAsync(new Uri(theURLYoureTryingToUse));
There's also WebRequest to look at too, that might work for what you're doing.
Edit: As for your "POST" edit, webclient lets you do post:
web.OpenWriteAsync(new Uri(theURLYoureTryingToUse), "POST");
you also then have to add an OpenWriteCompleted handler.
not sure exactly what you're doing, so you'll need to add more info to your question.
i want to build a piece of software that will process some html forms, the software will be a kind of bot that will process some forms on my website automatically.
Is there anyone who can give me some basic steps how to do this job...Any tutorials, samples, books or whatever can help me.
Can some of you post an working code with POST method ?
Check out How to: Send Data Using the WebRequest Class. It gives an example of how create a page that posts to another page using the HttpWebRequest class.
To fill out the form...
Find all of the INPUT or TEXTAREA elements that you want to fill out.
Build the data string that you are going to send back to the server. The string is formatted like "name1=value1&name2=value2" (just like in the querystring). Each value will need to be URL encoded.
If the form's "method" attribute is "GET", then take the URL in the "action" attribute, add a "?" and the data string, then make a "GET" web request to the URL.
If the form's "method" is "POST", then the data is submitted in a different area of the web request. Take a look at this page for the C# code.
To expand on David and JP's answers':
Assuming you're working with forms whose contents you're not familiar with, you can probably...
pull the page with the form via an HttpWebRequest.
load it into an XmlDocument
Use XPath to traverse/select the form elements.
Build your query string/post data based on the elements.
Send the data with HttWebRequest
If the form's structure is known in advance, you can really just start at #4.
(untested) example (my XPath is not great so the syntax is almost certainly not quite right):
HttpWebRequest request;
HttpWebResponse response;
XmlDocument xml = new XmlDocument();
string form_url = "http://...."; // you supply this
string form_submit_url;
XmlNodeList element_nodes;
XmlElement form_element;
StringBuilder query_string = new StringBuilder();
// #1
request = (HttpWebRequest)WebRequest.Create(form_url));
response = (HttpWebResponse)request.GetResponse();
// #2
xml.Load(response.GetResponseStream());
// #3a
form_element = xml.selectSingleNode("form[#name='formname']");
form_submit_url = form_element.GetAttribute("action");
// #3b
element_nodes = form_element.SelectNodes("input,select,textarea", nsmgr)
// #4
foreach (XmlNode input_element in element_nodes) {
if (query_string.length > 0) { query_string.Append("&"); }
// MyFormElementValue() is a function/value you need to provide/define.
query_string.Append(input_element.GetAttribute("name") + "=" + MyFormElementValue(input_element.GetAttribute("name"));
}
// #5
// This is a GET request, you can figure out POST as needed, and deduce the submission type via the <form> element's attribute.
request = (HttpWebRequest)WebRequest.Create(form_submit_url + "?" + query_string.ToString()));
References:
Link
http://www.developerfusion.com/forum/thread/26371/
http://msdn.microsoft.com/en-us/library/system.xml.xmlelement.getattribute.aspx
http://msdn.microsoft.com/en-us/library/system.xml.xmlelement.selectnodes.aspx
If you don't want to go the HttpWebRequest route, I would suggest WatiN. Makes it very easy to automate IE or Firefox and not worry about the internals of the HTTP requests.