How cURL POST image file works? - c#

I am trying to use the new Facebook Messenger Platform API to send image message using image file from application directory.
Facebook gives the example using cURL like below:
curl \
-F recipient='{"id":"USER_ID"}' \
-F message='{"attachment":{"type":"image", "payload":{}}}' \
-F filedata=#/tmp/testpng.png \
"https://graph.facebook.com/v2.6/me/messages?access_token=PAGE_ACCESS_TOKEN"
But I am trying to use the API with C#. For your information, I have successfully use the API if I use the file from an internet url.
I have tried to fill in the filedata property by using base64 string of the image file, but unsuccessful.
Kindly explain how does cURL works with the given file path especially image and create a POST request to the web server? And if possible, what options do I have to do it with C#?

The -F option is for form. This is equivalent to issuing a POST request with the Content-Type header of multipart/formdata and the request body containing all the key-value pairs listed with a proper boundary set. cURL will read the binary data and put the bytes in the correct boundary in the request. There are many examples online for C# to submit a multipart/formdata request. Look into HttpClient or WebClient file uploads and you'll find what you need.
I'll be away from a computer for a few days and submitting sample code from a mobile device isn't the easiest thing to do. If you need some sample code, let me know.

Related

Equivalent of curl "--path-as-is" in C# WebClient/WebRequest

The argument --path-as-is in CURL by definition sends the request with the URL path as is, without squashing (Do not squash .. sequences in URL path).
How can I achieve the same behavior in C# using either WebClient or WebRequest?

How to make a C# REST request using a Google Cloud JSON Service account file?

I'd like to leverage the new Google TTS using a simple rest request. To that end, I've created a Service Account which downloaded a JSON file containing a private key id, a private key, client email, client id, client_x509_cert_url, etc.
I've also set the environment variable for the system:
Environment.SetEnvironmentVariable("GOOGLE_APPLICATION_CREDENTIALS", jsonFile);
I then found this sample CURL request to use the WaveNet TTS engine provided by Google:
curl -H "Authorization: Bearer "$(gcloud auth application-default print-access-token) \
-H "Content-Type: application/json; charset=utf-8" \
--data "{
'input':{
'text':'Android is a mobile operating system developed by Google,
based on the Linux kernel and designed primarily for
touchscreen mobile devices such as smartphones and tablets.'
},
'voice':{
'languageCode':'en-gb',
'name':'en-GB-Standard-A',
'ssmlGender':'FEMALE'
},
'audioConfig':{
'audioEncoding':'MP3'
}
}" "https://texttospeech.googleapis.com/v1beta1/text:synthesize" > writtenfile.txt
I want to create a simple C# webrequest from the above CURL request, but the line "gcloud auth application-default print-access-token" is a problem for me. I cannot install a CLI gcloud instance on this machine. Isn't there some way to setup the webrequest authorization access token from the JSON service account file? Surely I don't HAVE to have gcloud installed.
Looking for code sample demonstrating how to convert CURL code to a C# rest request using the service account json file without gcloud.
In case you don't want to install the gcloud packages, you can execute REST calls by using API Keys. These keys can be created directly in the GCP console and they can be passed as a parameter through the request header; in this way, you can authenticate to the service without the need of gcloud. Additionally, I suggest you to take a look on this guide that contains the steps required to make REST requests with C#.
You can use this Restlet Client tool to test the following example:
REST content Example
Header
https://texttospeech.googleapis.com/v1beta1/text:synthesize?key=<YOUR_API_KEY>
Body
{
'input':{
'text':'Android is a mobile operating system developed by Google,
based on the Linux kernel and designed primarily for
touchscreen mobile devices such as smartphones and tablets.'
},
'voice':{
'languageCode':'en-gb',
'name':'en-GB-Standard-A',
'ssmlGender':'FEMALE'
},
'audioConfig':{
'audioEncoding':'MP3'
}
}
Finally, in case you want to consume a Service Account JSON file, you can use the Client libraries to create and send your TTS requests to then authenticate them directly from your code; however, this method require to install the TextToSpeech packages.

C# socket download file from REST API

I'm talking to a custom API, that will give me a file, if I send a GET request, with a body. And yes, I'm fully aware of how horrible that is, so please don't remind me.
I'm using Sockets to send the requests, and normally these GET requests return JSON data, which I can read just fine. However, I now need to download a file, and the socket keeps on closing. To be specific, I keep on getting this exception:
System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
If I use curl to make the request, I get the file:
curl -d '{"thing" : "blah"}' -H "Content-Type: application/json" -X GET http://127.0.0.1:1337/api/0.1/test/download > test.zip
If I use fiddler, I get the file returned.
But C# sockets keep on throwing that exception. I don't have any code to show, as I really don't know the best way to handle the data transfer. But I've tried no end of loops, and nothing seems to be working. If anyone could provide some guidance on how to do this, I'd appreciate it.
Thanks

Video Url Resolver for dailymotion and blip.tv

I'm stuck in getting the direct link of the video file on dailymotion and blip.tv website.
Ex:
direct video url of http: //www.dailymotion.com/video/x96bku_the-forest-short-animation-film_shortfilms is http: //proxy-36.dailymotion.com/video/684/114/15411486%3amp4_h264_aac_hq.mp4?auth=1281348558-2a834e9c8537ef9c8301dcae7c5c565a
http: //blip.tv/file/2765938/ -> http: //a52.video2.blip.tv/7320004900441/BenjaminHershleder-PixarOpeningParody552.flv
These links are captured by IDM
I appreciate any idea that could help me to resolve this problem.
Have you taken a look at Embedly? It allows you to give the url of a resource and receive the embed code for that resource.
While it might not give you the url directly, it will at least give you a structured format (the HTML) which you can then parse to try and get the video file data you need.

How to programatically upload/post an image to an image hosting website without a browser?

I want to write a simple utility to upload images to various free image hosting websites like TinyPic or Imageshack via a right-click context menu for the file.
How can I do this using .NET? I've seen some linux scripts that use cURL to post images to these website but I'm not sure how I could create the post request, complete with an image in C#?
Can someone point me in the right direction?
EDIT:
I've found a pretty good resource. Cropper, a free screenshot tool written in .net, has a lot of open-source plugins. One of them is a SendToTinyPic.. complete with source. Link here:
http://www.codeplex.com/cropperplugins
The FlickrNet API makes this extremely easy for working with Flickr from .NET. You have to have a Flickr account as well as an API key and shared secret. Once you have what you need, working with the API is very simple:
// http://www.flickr.com/services/api/misc.api_keys.html
string flickrApiKey = "<api key>";
string flickrApiSharedSecret = "<shared secret>";
string flickrAuthenticationToken = "<authentication token>";
Flickr flickr = new Flickr( flickrApiKey, flickrApiSharedSecret );
flickr.AuthToken = flickrAuthenticationToken;
foreach ( FileInfo image in new FileInfo[] {
new FileInfo( #"C:\image1.jpg" ),
new FileInfo( #"C:\image2.jpg" ) } )
{
string photoId = flickr.UploadPicture(
image.FullName, image.Name, image.Name, "tag1, tag2" );
}
Use HttpWebRequest.
Using this class, you can POST data to a remote HTTP address, just set the mime/type to multi-part/form encoded, and post the binary data from the image with the request.
http://msdn.microsoft.com/en-us/library/system.net.httpwebrequest(VS.71).aspx
For ImageShack, take a look to this Application.
TinyPic.com doesn't have an API as far as I know, but the Cropper SendToTinyPic Plugin tries to upload using "Screen scraping". The official version of the plugin doesn't work right now, but I put together a patch using the same approach, and submitted it to the cropperplugins project. It's just one source module that changed. Anyone can download the plugins project, and then drop in my patch and it should work.
With the patch, it's PritScrn or Alt-PrntScrn will save the image and upload to tinypic, and stuff the URL of the raw image on your clipboard. All in 2 seconds. easy.
If you don't want the actual tool, you can still look at the source code of my patch to see how to POST a page with form-data and a file upload. No direct link. See http://cropperplugins.codeplex.com/SourceControl/PatchList.aspx and look for #3239.
This example image was produced and then auto-uploaded to tinypic.com with the Alt-PrtScrn key-combo.
To embed it here, I just had to ctrl-V because the URL is stored on the clipboard.

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