Download and Unzip a Zip file with Node.js

1. Install a javascript zip implementation. I like adm-zip.

npm install adm-zip

1	npm install adm-zip

2. Require the node http module

var http = require('http')

1	var http = require('http')

3. Require the node file system module (fs)

var fs = require('fs')

1	var fs = require('fs')

5. Construct your temporary file path

var tmpFilePath = "assets/tmp/" + filename + ".zip"

1	var tmpFilePath = "assets/tmp/" + filename + ".zip"

6. Use http to get the url to the zip file, then synchronously append the data to the temporary file path. Use AdmZip to extract the zip to another directory.

7. Delete the zip file

Code and usage:

		var download = function(filename, url) {
			var tmpFilePath = "assets/tmp/" + filename + ".zip"
			http.get(url, function(response) {
		 		response.on('data', function (data) {
		 			fs.appendFileSync(tmpFilePath, data)
				});
		 		response.on('end', function() {
		 			 var zip = new AdmZip(tmpFilePath)
		 			 zip.extractAllTo("assets/extracted/" + filename)
		 			 fs.unlink(tmpFilePath)
			 	})
		 	});
		}

		for (var i = 0; i < objectsToDownload.length; i++) {
			download(objectsToDownload[i].filename, objectsToDownload[i].url)
		 }

var download = function(filename, url) {

var tmpFilePath = "assets/tmp/" + filename + ".zip"

http.get(url, function(response) {

response.on('data', function (data) {

fs.appendFileSync(tmpFilePath, data)

});

response.on('end', function() {

var zip = new AdmZip(tmpFilePath)

zip.extractAllTo("assets/extracted/" + filename)

fs.unlink(tmpFilePath)

})

});

}

for (var i = 0; i < objectsToDownload.length; i++) {

download(objectsToDownload[i].filename, objectsToDownload[i].url)

}

UIWebView Load PDF with Swift

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Sometimes you just want to load a pdf in a UIWebView, so here’s an extension to help you. A little bit of encapsulation can make the world of difference in readability and maintainability.

extension UIWebView {
    func loadPDF(name:String!) {
        let termsPath:String? = NSBundle.mainBundle().pathForResource(name, ofType: "pdf")!
        let url = NSURL(fileURLWithPath: termsPath!)
        let pdfRequest = NSURLRequest(URL: url!)
        self.loadRequest(pdfRequest)
    }
}

extension UIWebView {

func loadPDF(name:String!) {

let termsPath:String? = NSBundle.mainBundle().pathForResource(name, ofType: "pdf")!

let url = NSURL(fileURLWithPath: termsPath!)

let pdfRequest = NSURLRequest(URL: url!)

self.loadRequest(pdfRequest)

}

Usage:

self.webView.loadPDF("Terms")

1	self.webView.loadPDF("Terms")

UILabel and UIButton Font Kerning with Swift

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Here’s an extension to UILabel that kerns it’s text with a specified kerning value.

extension UILabel {
    func kern(kerningValue:CGFloat) {
        self.attributedText =  NSAttributedString(string: self.text ?? "", attributes: [NSKernAttributeName:kerningValue, NSFontAttributeName:font, NSForegroundColorAttributeName:self.textColor])
    }
}

extension UILabel {

func kern(kerningValue:CGFloat) {

self.attributedText = NSAttributedString(string: self.text ?? "", attributes: [NSKernAttributeName:kerningValue, NSFontAttributeName:font, NSForegroundColorAttributeName:self.textColor])

}

Usage:

mylabel.kern(1.5)

1	mylabel.kern(1.5)

This extension to UIButton kerns the text in it’s titleLabel property.

extension UIButton {
    func kern(kerningValue:CGFloat) {
        let attributedText =  NSAttributedString(string: self.titleLabel!.text!, attributes: [NSKernAttributeName:kerningValue, NSFontAttributeName:self.titleLabel!.font, NSForegroundColorAttributeName:self.titleLabel!.textColor])
        self.setAttributedTitle(attributedText, forState: UIControlState.Normal)
    }
}

extension UIButton {

func kern(kerningValue:CGFloat) {

let attributedText = NSAttributedString(string: self.titleLabel!.text!, attributes: [NSKernAttributeName:kerningValue, NSFontAttributeName:self.titleLabel!.font, NSForegroundColorAttributeName:self.titleLabel!.textColor])

self.setAttributedTitle(attributedText, forState: UIControlState.Normal)

}

Usage:

mybutton.kern(1.5)

1	mybutton.kern(1.5)

Note, as of XCode 6.2, the UIButton type must be custom so that the UIButton is resized with the kerned text. Resizing behavior occurs without a call to sizeToFit() or invalidateIntrinsicContentSize().

iOS Font Kerning with Swift and NSAttributedString

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From Wikipedia –

In typography, kerning (less commonly mortising) is the process of adjusting the spacing between characters in a proportional font, usually to achieve a visually pleasing result.

Today I received a PSD with kerned fonts, so I created a type level method in Swift that lets me create an attributed string by specifying a kerning value.

class func attributedString(string text:String, withFont font:UIFont!, kerning: CGFloat!, andColor color:UIColor!) -> NSAttributedString?  {
    return NSAttributedString(string: text, attributes: [NSKernAttributeName:kerning, NSFontAttributeName:font, NSForegroundColorAttributeName:color])
}

class func attributedString(string text:String, withFont font:UIFont!, kerning: CGFloat!, andColor color:UIColor!) -> NSAttributedString? {

return NSAttributedString(string: text, attributes: [NSKernAttributeName:kerning, NSFontAttributeName:font, NSForegroundColorAttributeName:color])

}

Now lets say this method was in a class called “AppearanceService”, this usage would be like this:

let attributedText:NSAttributedString? = AppearanceService.attributedString(string: "Kern it, Kern it good.", withFont: AppearanceService.mediumFont(size: 15), kerning: 1.5, andColor: UIColor.whiteColor())

1	let attributedText:NSAttributedString? = AppearanceService.attributedString(string: "Kern it, Kern it good.", withFont: AppearanceService.mediumFont(size: 15), kerning: 1.5, andColor: UIColor.whiteColor())

Resize UIImage in Swift and iOS 8

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Here is an extension to UIImage that adds a public method called resize(size:CGSize, completionHandler:(resizedImage:UIImage, data:NSData)->()). The image is resized on a global concurrent queue and the completion handler is called on the main queue with the new UIImage and image data. Good for resizing images before sending them to a server. The jpeg compression ratio should probably also be parameterized! Enjoy!

extension UIImage {
    public func resize(size:CGSize, completionHandler:(resizedImage:UIImage, data:NSData)->()) {
        dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0), { () -> Void in
            var newSize:CGSize = size
            let rect = CGRectMake(0, 0, newSize.width, newSize.height)
            UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)
            self.drawInRect(rect)
            let newImage = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
            let imageData = UIImageJPEGRepresentation(newImage, 0.5)
            dispatch_async(dispatch_get_main_queue(), { () -> Void in
                completionHandler(resizedImage: newImage, data:imageData)
            })
        })
    }
}

extension UIImage {

public func resize(size:CGSize, completionHandler:(resizedImage:UIImage, data:NSData)->()) {

dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0), { () -> Void in

var newSize:CGSize = size

let rect = CGRectMake(0, 0, newSize.width, newSize.height)

UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)

self.drawInRect(rect)

let newImage = UIGraphicsGetImageFromCurrentImageContext()

UIGraphicsEndImageContext()

let imageData = UIImageJPEGRepresentation(newImage, 0.5)

dispatch_async(dispatch_get_main_queue(), { () -> Void in

completionHandler(resizedImage: newImage, data:imageData)

})

}

Open App Settings in iOS 8

1 Reply

Apple, Y is this so poorly documented?

1. Add a key to your app-info.plist file called UIApplicationOpenSettingsURLString

2. Set the value of this key to “app-settings:”

3. In your code, access this value as a global constant:

NSString *const UIApplicationOpenSettingsURLString

1	NSString *const UIApplicationOpenSettingsURLString

in Objective-C, and

let UIApplicationOpenSettingsURLString: NSString!

1	let UIApplicationOpenSettingsURLString: NSString!

in Swift

4. Use this global constant like so :

[UIApplication sharedApplication] openURL:[NSURL URWithString: UIApplicationOpenSettingsURLString]]

1	[UIApplication sharedApplication] openURL:[NSURL URWithString: UIApplicationOpenSettingsURLString]]

in Objective C and

UIApplication.sharedApplication().openURL(NSURL(UIApplicationOpenSettingsURLString))

1	UIApplication.sharedApplication().openURL(NSURL(UIApplicationOpenSettingsURLString))

in Swift.

Use canOpenURL: to test if this is possible during run time. It is not possible on iOS 7. I also wonder if there are paths you can add after “app-settings:” to open specific app settings screens such as privacy. Please leave a comment if you have any information on this.

Swift Optional Type NSString! can not be used as a boolean

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Did you import UIKit?

Get Application Documents directory in iOS Using Swift

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Heres the snippet:


func applicationDocumentsDirectory()->NSString {
        let paths:NSArray = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
        let basePath: AnyObject! = (paths.count > 0) ? paths.objectAtIndex(0) : nil
        return basePath as NSString;
}

func applicationDocumentsDirectory()->NSString {

let paths:NSArray = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)

let basePath: AnyObject! = (paths.count > 0) ? paths.objectAtIndex(0) : nil

return basePath as NSString;

}

Copy a pre-populated SQLite file to documents directory for Core Data using Swift

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Here is a quick snippet that shows how to check for the existence of a sqlite file in the documents directory and how to copy the file from the app bundle to the documents directory if it does not exists. This should be done before adding the persistent store to the persistent store coordinator ensure that there is pre-populated data
.

let storePath : NSString = self.applicationDocumentsDirectory().stringByAppendingPathComponent("MyDb.sqlite")
        let fileManager : NSFileManager = NSFileManager.defaultManager()
        var fileCopyError:NSError? = NSError()
        if !fileManager.fileExistsAtPath(storePath) {
            let defaultStorePath : NSString! = NSBundle.mainBundle().pathForResource("MyDb", ofType: "sqlite")
            if(defaultStorePath) {
                fileManager.copyItemAtPath(defaultStorePath, toPath: storePath, error: &fileCopyError)
            }
        }

let storePath : NSString = self.applicationDocumentsDirectory().stringByAppendingPathComponent("MyDb.sqlite")

let fileManager : NSFileManager = NSFileManager.defaultManager()

var fileCopyError:NSError? = NSError()

if !fileManager.fileExistsAtPath(storePath) {

let defaultStorePath : NSString! = NSBundle.mainBundle().pathForResource("MyDb", ofType: "sqlite")

if(defaultStorePath) {

fileManager.copyItemAtPath(defaultStorePath, toPath: storePath, error: &fileCopyError)

}

Using NSURLSession and NSURLSessionDataTask in Swift to make a GET request

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Make a simple GET request using NSURLSession and NSURLSessionDataTask. Here i’m creating a singleton that has access to ‘network’ struct that has a computed property called session.
//API.swift

public struct network {
    public var session:NSURLSession? {
    get {
        let sessionConfig = NSURLSessionConfiguration.defaultSessionConfiguration()
        sessionConfig.HTTPAdditionalHeaders = ["API-KEY": "ABCDEF"];
        return NSURLSession(configuration: sessionConfig)
    }
    }
}

class API {
    class var sharedInstance : API {
    struct Static {
        static let instance : API = API()
        }
        return Static.instance
    }

//name argument isn't used in this method, 

    func apiRequest(name:String, completionblock:(error:NSError, wordInformation:NSDictionary)->()) {
        let session = network().session!;
        let task : NSURLSessionDataTask = session.dataTaskWithURL(NSURL(string:"https://url_here"),completionHandler: {(data: NSData!, response: NSURLResponse!, error: NSError!) -> Void in
            let JSON: AnyObject! = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.AllowFragments, error: nil)
            NSLog(JSON!.description)
            return
            })
        task.resume()
    }
}

public struct network {

public var session:NSURLSession? {

get {

let sessionConfig = NSURLSessionConfiguration.defaultSessionConfiguration()

sessionConfig.HTTPAdditionalHeaders = ["API-KEY": "ABCDEF"];

return NSURLSession(configuration: sessionConfig)

}

class API {

class var sharedInstance : API {

struct Static {

static let instance : API = API()

}

return Static.instance

}

//name argument isn't used in this method,

func apiRequest(name:String, completionblock:(error:NSError, wordInformation:NSDictionary)->()) {

let session = network().session!;

let task : NSURLSessionDataTask = session.dataTaskWithURL(NSURL(string:"https://url_here"),completionHandler: {(data: NSData!, response: NSURLResponse!, error: NSError!) -> Void in

let JSON: AnyObject! = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.AllowFragments, error: nil)

NSLog(JSON!.description)

return

})

task.resume()

}

In your ViewController.swift file or another file that references the API class use this:


API.sharedInstance.apiRequest("name", completionblock: {(error: NSError, responseDictionary: NSDictionary) -> () in
//Set variables and do further processing here
 })

API.sharedInstance.apiRequest("name", completionblock: {(error: NSError, responseDictionary: NSDictionary) -> () in

//Set variables and do further processing here

})

Rajiev

I build high quality software.

Download and Unzip a Zip file with Node.js

UIWebView Load PDF with Swift

UILabel and UIButton Font Kerning with Swift

iOS Font Kerning with Swift and NSAttributedString

Resize UIImage in Swift and iOS 8

Open App Settings in iOS 8

Swift Optional Type NSString! can not be used as a boolean

Get Application Documents directory in iOS Using Swift

Copy a pre-populated SQLite file to documents directory for Core Data using Swift

Using NSURLSession and NSURLSessionDataTask in Swift to make a GET request