I converted ipad signature to png image successfully using UIImagePNGRrepresentation(Image). Now I want to store this Image from swift to a SQL Server database using a web service. I have not any idea about how do this?
This is my swift code
UIGraphicsBeginImageContextWithOptions(self.signatureMainImageview.bounds.size, false, 0.0)
self.signatureMainImageview.image?.drawInRect(CGRectMake(0, 0, self.signatureMainImageview.frame.size.width, self.signatureMainImageview.frame.size.height))
let SaveImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
let image = UIImagePNGRepresentation(SaveImage)
var CardDataObj = structCardData()
CardDataObj.CustomerSignature = image!
let requestCardData = NSMutableURLRequest(URL: NSURL(string: "http://URL")!)
requestCardData.HTTPMethod = "POST"
let postString = CardDataObj.jsonRepresentation
requestCardData.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
let task = NSURLSession.sharedSession().dataTaskWithRequest(requestCardData) {
data, response, error in
if error != nil {
print("error=\(error)")
return
}
print("response = \(response)")
let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
print("responseString = \(responseString)")
}
Now I want to know how to get this image in webservice? which datatype use in webservice for image? which datatype use in sql for image? How to send this image to sql?
Rather than a data task you need an upload task. Either uploadTaskWithRequest:fromData:completionHandler or its file or stream variants
In order to begin the task you need to call task.resume()
It also helps to retrieve the response if you cast to HTTPURLResponse like so:
if let response = response as? NSHTTPURLResponse {
response.statusCode
response.allHeaderFields
}
I wrote a blogpost on uploading using a stream, which might be of some use. Here's also a more general post about NSURLSession.
The first blogpost linked to will give you some server-side code in PHP to receive a stream, but if you are uncertain about what to do on the SQL I'd recommended breaking this question into two and asking that question separately.
Related
Supabase is wonderful !! I am trying to upload an image to the public bucket using POST request to <SUPABASE_URL>/storage/v1/object/<BUCKET_NAME>/<IMAGE_NAME>.
The difficult is I have only base64 encoded image string and I am not able to make a successful request to above endpoint. Have tried numerous iterations of setting Content-type but no luck.
I am trying to upload my image from Appsmith which provides base64 format for the image from where I will have to hit the above endpoint.
Please help me out here.
I'm glad to be able to find another Supabase fan like me!
I hear your pain. Could you try this technique to convert base 64 string to a blob object?
const byteCharacters = atob(b64Data);
const byteNumbers = new Array(byteCharacters.length);
for (let i = 0; i < byteCharacters.length; i++) {
byteNumbers[i] = byteCharacters.charCodeAt(i);
}
const byteArray = new Uint8Array(byteNumbers);
const blob = new Blob([byteArray], {type: contentType});
The blob variable at the end is the variable you can use to upload to Supabase.
Also, have you considered using the Supabase-js SDK? It will make your life a lot easier as they provide better API's to interact with Supabase.
You can get the supabase-js package here:
https://www.npmjs.com/package/#supabase/supabase-js
And you can find some sample code here:
https://supabase.io/docs/reference/javascript/storage-from-upload
In your case, you could do something like this to upload your file:
const { data, error } = await supabase
.storage
.from('avatars')
.upload('public/sample.png', blob, {
cacheControl: 3600,
upsert: false
})
I am building an app where people need to fill out a form and then it creates an HTTP post where the API will return a Json file to the app with data I need. Everything is working fine with accessing the API however I want to parse the data in another view controller. How can I access the JSON file from another view controller?
let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
guard error == nil else {
return
}
guard let data = data else {
return
}
do {
//create json object from data
if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] {
print(json)
^^^^^^^
How do I take this JSON file to the next view controller so I dont have to do the parsing below?
let jsonData = json
let ratesJson = jsonData["rates"]!
let rates = ratesJson as! NSArray
print("Rates: \(rates)")
print("*************")
print(rates.count)
print("*************")
for item in 0..<rates.count {
let specificRate = rates[item]
let price = (specificRate as AnyObject)["amount_local"]!
let provider = (specificRate as AnyObject)["provider"]!
print("--\(item)--")
print("Price: \(price!)")
print("Provider: \(provider!)")
}
}
} catch let error {
print(error.localizedDescription)
}
})
I assume by your comment, your intention is to actually pass a JSON object, not a JSON file to the next view controller.
Therefore, you just need to pass the JSON object to your segue and assign it as a property to the next view controller.
Since the question was very open ended, here is one possible solution and interpretation.
Example:
//Sample snippet from code from question
if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] {
performSegue(withIdentifier: "MySegue", sender: json);
}
override func prepare(for segue: UIStoryboardSegue!, sender: Any?) {
if (segue.identifier == "MySegue") {
let vc = segue.destinationViewController as! RandomViewController
vc.json = sender as! [String:Any];
}
}
One of the things that usually cause bugs in programs is state. What you are asking here in my opinion is state.
What I would do is i would write a generic function ( Swift encourages functional programming in a lot of cases, have a look at: swift map, filter etc. that deals with the HTTP request and returning the data in a closure.
This closure will then live within the view controller you want your json object in, thus solving your problem of accessing said data.
Now I don't believe that is the right approach either. I would create an object for your specific data returned, like say a "struct Person" or whatever your needs are.
This has 2 advantages:
In swift 3.1 you can have a custom init() method that parses the JSON safely ( remember, optionals! ) and populates the structs data accordingly
In swift 4.0 and Xcode9.0 You will be able to morph the struct you just created to conform to the Codable and Decodable protocols with wich json parsing will be greatly simplified, as explained here: ultimate swift json guide
Hope this was of any help.
I'm implementing file download using AngularJS and WCF. My back-end is a .NET project hosted in IIS. The file is serialized as an array of bytes and then on the client side I utilize the File API to save the content.
To simplify the problem, back-end is like:
[WebInvoke(Method = "GET", UriTemplate = "FileService?path={path}")]
[OperationContract]
public byte[] DownloadFileBaseOnPath(string path)
{
using (var memoryStream = new MemoryStream())
{
var fileStream = File.OpenRead(path);
fileStream.CopyTo(memoryStream);
fileStream.Close();
WebOperationContext.Current.OutgoingResponse.Headers["Content-Disposition"] = "attachment; filename=\"Whatever\"";
WebOperationContext.Current.OutgoingResponse.ContentType = "application/octet-stream"; // treat all files as binary file
return memoryStream.ToArray();
}
}
And on client side, it just sends a GET request to get those bytes, converts in into a blob and save it.
function sendGetReq(url, config) {
return $http.get(url, config).then(function(response) {
return response.data;
});
}
Save the file then:
function SaveFile(url) {
var downloadRequest = sendGetReq(url);
downloadRequest.then(function(data){
var aLink = document.createElement('a');
var byteArray = new Uint8Array(data);
var blob = new Blob([byteArray], { type: 'application/octet-stream'});
var downloadUrl = URL.createObjectURL(blob);
aLink.setAttribute('href', downloadUrl);
aLink.setAttribute('download', fileNameDoesNotMatter);
if (document.createEvent) {
var event = document.createEvent('MouseEvents');
event.initEvent('click', false, false);
aLink.dispatchEvent(event);
}
else {
aLink.click();
}
setTimeout(function () {
URL.revokeObjectURL(downloadUrl);
}, 1000); // cleanup
});
}
This approach works fine with small files. I could successfully download files up to 64MB. But when I try to download a file larger than 64MB, the response.body is empty in Chrome. I also used Fiddler to capture the traffic. According to Fiddler, Back-end has successfully serialized the byte array and returned it. Please refer to the screenshot below.
In this example, I was trying to download a 70MB file:
And the response.data is empty:
Any idea why this is empty for file over 70MB? Though the response itself is more than 200MB, I do have enough memory for that.
Regarding to the WCF back-end, I know I should use Stream Mode when it comes to large files. But the typical use of my application is to download files less than 10MB. So I hope to figure this out first.
Thanks
Answer my own question.
Honestly I don't know what's going wrong. The issue still persists if I transfer it as a byte array. I eventually gave up this approach by returning a stream instead. Then on the client side, adding the following configuration
{responseType : blob}
and save it as a blob.
I am met with a problem when I tried to download a batch of images off firebase storage. Basically, because the file sizes differ, the images are not appended to the image array properly causing the images to be in the wrong order that I wanted. Below is the code
import Foundation
import FirebaseStorage
class GalleryCellDetailedData {
var selectedGallery:String?
var count:Int
init(selectedGallery:String?,count:Int){
self.selectedGallery = selectedGallery
self.count = count
}
func addImages(completion:(data:[NSData])->()){
var datas = [NSData]()
let myGroup = dispatch_group_create()
for i in 0..<count {
dispatch_group_enter(myGroup)
getImage(i, completion: { (image:NSData) in
datas.append(image)
print("Finish Request \(i)")
dispatch_group_leave(myGroup)
})
}
dispatch_group_notify(myGroup, dispatch_get_main_queue(), {
completion(data: datas)
})
}
private func getImage(number:Int, completion:(image:NSData)->()){
let storage = FIRStorage.storage()
//Reference to Firebase Profile Picture Storage
let storageRef = storage.referenceForURL("gs://mannacatering-addcb.appspot.com")
print("Initiating Image Download")
let galleryPicRef = storageRef.child("Gallery/\(selectedGallery!)/g\(String(number)).jpg")
//Download Image
galleryPicRef.dataWithMaxSize(1 * 1024 * 1024) { (data, error) -> Void in
if (error != nil) {
print("fail to download image")
}
dispatch_async(dispatch_get_main_queue(), {
print("Dispatching image")
completion(image:data!)
})
}
}
}
I split them up into 2 separate functions because I tried to manage them in a single function and the order is in a mess as well and I thought this might work but apparently not.
Instead of storing your data in an array, store it in a dictionary. The key can be the number i or however you want to refer to an image when you use it.
I recommend taking an approach similar to Storing multiple images into firebase and getting urls, where you store the URLs in the Realtime Database, and use that as your source of truth for ordering, display, etc. It's far easier and makes for better apps :)
I have a remote server which has profile data and an image and when I retrieve it, I get the image url, which I can display using the <img> tag, by using the url.
When I have to modify the details, I send a new image, for which I upload a new image using a small AngularJS function and send the whole data using formData and http request.
But, out of curiosity, I was wondering whether there is any way to send an object of the same image using the url I received from the server.
Another reason I thought of it was that I was thinking of maybe changing its dimensions,etc.
Just in case if I ever needed to generate a thumbnail of the image of a smaller size in future.
Solved it myself by looking around and generating a canvas from the url, through dataURI by using the function :
var byteString = atob(dataURI.split(',')[1]);
var ab = new ArrayBuffer(byteString.length);
var ia = new Uint8Array(ab);
for (var i = 0; i < byteString.length; i++) {
ia[i] = byteString.charCodeAt(i);
}
var blob= new Blob([ab], { type: 'image/jpeg' });
to create a blob to send the image back after scaling(was required).