I am presenting some photos into a collectionView. I am getting some URL's from the server and I do a request with KingFisher. My problem is that the URLs I have include images with more than 2000x1000 pixels. Can I avoid downloading such big photos and instead requesting a smaller version of that image? I don't want to download and then resize cause that will not speed things up. Thanks.
My code :
self.image.kf.setImage(with: URL(string:imageUrl)!, placeholder: UIImage(named: "placeholderImage"), options: nil, progressBlock: { receivedSize, totalSize in
print(totalSize)
}, completionHandler: nil)
Related
I am using AlamofireImage library to download/cache web images and show it in UIImageView inside tableViewCells.
imageView.af_setImage(withURL: url, placeholderImage: nil, filter: nil, imageTransition: .crossDissolve(0.3), runImageTransitionIfCached: true, completion: { (response) in
//...... other code .....
})
It works perfect for .png/.jpg or other still images but I am not able to show GIF images using this.
I tried using external library to convert imageData to gif images and it works perfect however Alamofire is not caching the gif data and next time the image loads as still image.
Check the code below:
imageView.af_setImage(withURL: url, placeholderImage: nil, filter: nil, imageTransition: .crossDissolve(0.3), runImageTransitionIfCached: true, completion: { (response) in
if imageUrl.hasSuffix("gif") {
if let data = response.data{
self.imageView.image = UIImage.gifImageWithData(data)
}
}
})
The above code shows the GIF for first time but next time only still image appears.
Any idea how the following can be achieved using AlamofireImage:
Download the GIF imageData for the first time, cache it and show GIF to imageView
Next time get the imageData from cache and show GIF again
I have not found a direct way to play GIF with AlamofireImage but we can do using SwiftyGif. I'm using AlamofireImage throughout the app but for display GIF and load from the server, I'm using SwiftyGif. Using SwiftyGif you can play, load from the server as well as locally. I think it will be reliable solution instead of use SDWebImage.
SwiftyGif
// You can also set it with an URL pointing to your gif
let url = URL(string: "...")
let loader = UIActivityIndicatorView(style: .white)
cell.gifImageView.setGifFromURL(url, customLoader: loader)
Download GIF file , next time get the file and show
Alamofire.download(gifUrl, to: destination).responseJSON(completionHandler: {
response in
if let filePath = response.destinationURL?.path{
if let gifImage = UIImage.init(contentsOfFile: filePath){
self.imageVIew.image = gifImage
}
}
})
I've a string in which I've comma separated links of images. Here is how I'm splitting it into an array: let imagesLinks = imageLins.components(separatedBy: ","). Then I've used for loop to get one link, download the image and storing it in a UIImage array in this way:
for imag in imagesLinks
{
let img = UIImageView()
print("\(baseReportImageURL)\(imag)")
img.sd_setImage(with: URL(string: "\(baseReportImageURL)\(imag)"), placeholderImage: nil)
imagesArray.append(img.image!)
}
The print statement is giving me the correct URL which when I open on browser downloads the image. The problem is on the line where I'm appending the array i.e. imagesArray.append(img.image!). I get:
fatal error: unexpectedly found nil while unwrapping an Optional value
and
fatal error: unexpectedly found nil while unwrapping an Optional value
So what would be the correct solution for this?
UPDATE
My question is different because I'm using SDWebImage and when I use completion block there is a strange behaviour of the app:
img.sd_setImage(with: imgURL, placeholderImage: nil,options: SDWebImageOptions(rawValue: 0), completed: { (image, error, cacheType, imageURL) in
activityIndicator.stopAnimating()
imagesArray.append(image!)
self.photoCollection.reloadData()
})
So it keeps on rotating the activity indicator and when I go back and push the view again it load the images instantly. So I think that the completion block is not called when the image is downloaded but why is that?
I think that is not the proper way to get downloaded images (set images to an UIImageView and then get the images from there).
You should use the image downloader, provided by SDWebImage:
SDWebImageManager.shared().imageDownloader?.downloadImage(with: <YOUR_URL>, options: [], progress: { (received, expected, nil) in
print(received,expected)
}, completed: { (image, data, error, true) in
yourArray.append(image)
})
If you have indexes, you can update the current row in the tableview every time when an image downloaded, or just reload() the whole, but I recommend the first.
It is because
imagesArray.append(img.image!)
Image take some times for downloading. When you do imagesArray.append(img.image!) at that time it is possible that your image is not set to your imageview and that means you are trying to add nil in your imageArray!
Second thing why are you storing image in an array ? You have array of urls and you are using SDWebImage then every time when you want to display image use SDWebImage. No need to store in array!
And if you want images in array anyhow than use NSUrlSession asynchronous requests with completion handlers and from completion handler add image to your array!
Append the image into the images array in the sd_setImage completion block.
The image is not yet downloaded when you are trying to add it into the array, and check if the image is not equal nil before adding it.
Use this Block For Image Download After download Perform Operation(append Image)
cell.appIcon.sd_setImage(with: url!, placeholderImage: UIImage(named: "App-Default"),options: SDWebImageOptions(rawValue: 0), completed: { (image, error, cacheType, imageURL) in
// Perform operation.
//append Image Here
})
i downloaded images from the server with alamofire framework. I worked with Alamofire.download . Each image has size above 1MB +-, but after each request memory increase a lot. After downloading 4 images the memory used is above 171MB and after that each image give more than 35MB.
Downloading code is:
Alamofire.download(mainReguest, to: self.destination)
.downloadProgress{ progress in
self.progressView.progress = Float(progress.fractionCompleted)
}
.response{ response in
if response.error == nil, let imagePath = response.destinationURL?.path {
let image = UIImage(contentsOfFile: imagePath)
self.addNewImageToTheScrollView(img: image)
}
}
}
Code with destination is:
let destination = DownloadRequest.suggestedDownloadDestination(for: .documentDirectory,
in: .userDomainMask,
with: [DownloadRequest.DownloadOptions.removePreviousFile])
The problem is with this...
UIImage(contentsOfFile: imagePath)
Specifically with the fact that you are (presumably) downloading a compressed format of your image.
However, UIImage is uncompressed in memory. So each pixel of your image will take 4 bytes of information (red, green, blue, alpha).
So if you have an image that is (for example) 5 mega pixels.
Then 5,000,000 pixels * 4b = 20MB.
So, I imagine your images are around 10MP?
The best way around this is to optimise your image download. If you're displaying an image on an iPhone then there is no point downloading a 10MP version of it. You might as well resize it to be much much smaller.
Ideally, you should be resizing the images on the backend before the download happens.
Your Alamofire's code is ok. Most likely you have issues somewhere in UI part, for example because of the high image resolution. The first thing you have to do is to localise an issue. To check networking code please comment all UI related code and run your app one more time.
Alamofire.download(mainReguest, to: self.destination)
.downloadProgress{ progress in
// self.progressView.progress = Float(progress.fractionCompleted)
}
.response{ response in
if response.error == nil, let imagePath = response.destinationURL?.path {
let image = UIImage(contentsOfFile: imagePath)
print("Image is successfully downloaded!")
//self.addNewImageToTheScrollView(img: image)
}
}
}
func loadCell(personObj:Person){
self.lblTitle.text = personObj.title
self.lblDesc.text = personObj.desc
print("ImgUrlInCell:", personObj.imageUrl)
do {
self.imgPicture.image = try UIImage(data:NSData(contentsOf:NSURL(string: personObj.imageUrl) as! URL) as Data)
} catch {
print("Error:",error)
}
}
Firstly, I've parsed data from API and put it in object and then insert it into database. At the time of displaying data I fetched them from database and list them in Tableview.
If there is an internet connection everything is working fine
If there is no internet connection image url doesn't work, It prints error 6 times. (I have 10 images in database or API)
Also, There are 10 image url displaying in console in ImgUrlInCell:
Please someone help me with this issue. What have I wronged.
You are using TableView and in TableView as per screen size and Cell size, it will show max cell in your screens so it may be possible that in your case its loading 6 cells data and all 6 cells have load image method so its throwing error 6 times.
To load Images lazily there are many famous libraries which will manage single time download and cache that image.
SDWebImage is one of the best libraries fits for your problem.
Link : SDWebImage
And follow below code to get Image from the server.
Swift:
import SDWebImage
imageView.sd_setImage(with: URL(string: "http://www.example.com/path/to/image.jpg"), placeholderImage: UIImage(named: "placeholder.png"))
Put an above line of code in your loadCell method with your imageURL.
Please check Internet connection by using Apple Reachability classes and load your image if the Internet connection is there.
Edit:
For Locally storing image you can use below function of SDWebImage Downloader and cache your image before showing it to the user.
SDWebImageManager.shared().imageDownloader?.downloadImage(with: NSURL(string: strURL) as URL!, options: SDWebImageDownloaderOptions.continueInBackground, progress: {
(receivedSize, ExpectedSize, imageURL) in
print("receive:",receivedSize,"Expected:",ExpectedSize,"Image URL:",imageURL ?? "No URL")
}, completed: {
(image, data, error, finished) in
print("Image Data:",data ?? "No Data")
// Do your stuff to store downloaded image
})
Link : Reachability Sample
Hope this will helps.
I'm using SDWebImage library to cache web images in my UICollectionView:
cell.packItemImage.sd_setImage(with: URL(string: smileImageUrl[indexPath.row]))
but I want to save the cached images locally in a file instead of downloading them again
FileManager.default.createFile(atPath: newPath, contents: Data(contentsOf: URL(string: snapchildvalue[Constants.smiles.smileImageUrl] as! String)!), attributes: nil)
is there a way to get the data of cached images
SDWebImage caches downloaded images automatically by default. You can use SDImageCache to retrieve images from the cache. There is a memory cache for the current app session, which will be quicker, and there is the disk cache. Example usage:
if let image = SDImageCache.shared().imageFromDiskCache(forKey: imageURL.absoluteString) {
//use image
}
if let image = SDImageCache.shared().imageFromMemoryCache(forKey: imageURL.absoluteString) {
//use image
}
Also make sure you import SDWebImage in your file. (If you're using Swift/Carthage, it will be import WebImage
SDWebimage chaches image once it is downloaded from a url. Basically it saves image against a url and next time if an image is available for a URL. It will simply get that image from cache. So the below method will be called instantly if the image is already downloaded to device.
imgView.sd_setImage(with: URL(string:url), completed: { (image, error, type, url) in
imgView.image = image
//Do any thing with image here. This will be called instantly after image is downloaded to cache. E.g. if you want to save image (Which is not required for a simple image fetch,
//you can use FileManager.default.createFile(atPath: newPath, contents: UIImagePNGRepresentation(image), attributes: nil)
})
Still if you want to save that image somewhere else or modify it or whatever, you can do it in the completion block above.
SDWebImage already have this kind of caching file locally
Create a SDImageCache with namespace of your choice
Try get the image with imageCache.queryDiskCache
If the image exist, set it to your imageview, if not, use sd_setImage to get the image then save it to the local cache with SDImageCache.shared().store
The key usually to be the image url string
Something like this, might not be correct syntax:
imageCache.queryDiskCache(forKey: urlForImageString().absoluteString, done: {(_ image: UIImage, _ cacheType: SDImageCacheType) -> Void in
if image {
self.imageView.image = image
}
else {
self.imageView.sd_setImage(withURL: urlForImageString(), placeholderImage: UIImage(named: "placeholder")!, completed: {(_ image: UIImage, _ error: Error, _ cacheType: SDImageCacheType, _ imageURL: URL) -> Void in
SDImageCache.shared().store(image, forKey: urlForImageString().absoluteString)
})
}
})