I am consuming an API that gives me the next page in the Header inside a field called Link. (For example Github does the same, so it isn't weird.Github Doc)
The service that I am consuming retrieve me the pagination data in the following way:
As we can see in the "Link" gives me the next page,
With $0.response?.allHeaderFields["Link"]: I get </api/games?page=1&size=20>; rel="next",</api/games?page=25&size=20>; rel="last",</api/games?page=0&size=20>; rel="first".
I have found the following code to read the page, but it is very dirty... And I would like if anyone has dealt with the same problem or if there is a standard way of face with it. (I have also searched if alamofire supports any kind of feature for this but I haven't found it)
// MARK: - Pagination
private func getNextPageFromHeaders(response: NSHTTPURLResponse?) -> String? {
if let linkHeader = response?.allHeaderFields["Link"] as? String {
/* looks like:
<https://api.github.com/user/20267/gists?page=2>; rel="next", <https://api.github.com/user/20267/gists?page=6>; rel="last"
*/
// so split on "," the on ";"
let components = linkHeader.characters.split {$0 == ","}.map { String($0) }
// now we have 2 lines like '<https://api.github.com/user/20267/gists?page=2>; rel="next"'
// So let's get the URL out of there:
for item in components {
// see if it's "next"
let rangeOfNext = item.rangeOfString("rel=\"next\"", options: [])
if rangeOfNext != nil {
let rangeOfPaddedURL = item.rangeOfString("<(.*)>;", options: .RegularExpressionSearch)
if let range = rangeOfPaddedURL {
let nextURL = item.substringWithRange(range)
// strip off the < and >;
let startIndex = nextURL.startIndex.advancedBy(1) //advance as much as you like
let endIndex = nextURL.endIndex.advancedBy(-2)
let urlRange = startIndex..<endIndex
return nextURL.substringWithRange(urlRange)
}
}
}
}
return nil
}
I think that the forEach() could have a better solution, but here is what I got:
let linkHeader = "</api/games?page=1&size=20>; rel=\"next\",</api/games?page=25&size=20>; rel=\"last\",</api/games?page=0&size=20>; rel=\"first\""
let links = linkHeader.components(separatedBy: ",")
var dictionary: [String: String] = [:]
links.forEach({
let components = $0.components(separatedBy:"; ")
let cleanPath = components[0].trimmingCharacters(in: CharacterSet(charactersIn: "<>"))
dictionary[components[1]] = cleanPath
})
if let nextPagePath = dictionary["rel=\"next\""] {
print("nextPagePath: \(nextPagePath)")
}
//Bonus
if let lastPagePath = dictionary["rel=\"last\""] {
print("lastPagePath: \(lastPagePath)")
}
if let firstPagePath = dictionary["rel=\"first\""] {
print("firstPagePath: \(firstPagePath)")
}
Console output:
$> nextPagePath: /api/games?page=1&size=20
$> lastPagePath: /api/games?page=25&size=20
$> firstPagePath: /api/games?page=0&size=20
I used components(separatedBy:) instead of split() to avoid the String() conversion at the end.
I created a Dictionary for the values to hold and removed the < and > with a trim.
I have a long string in swift3 and want to check if it contains word1 and word2. It could also be more than 2 search words. I found out following solution:
var Text = "Hello Swift-world"
var TextArray = ["Hello", "world"]
var count = 0
for n in 0..<TextArray.count {
if (Text.contains(TextArray[n])) {
count += 1
}
}
if (count == TextArray.count) {
print ("success")
}
But this seems very complicated, is there not an easier way to solve this? (Xcode8 and swift3)
If you are looking for less code:
let text = "Hello Swift-world"
let wordList = ["Hello", "world"]
let success = !wordList.contains(where: { !text.contains($0) })
print(success)
It is also a little more efficient than your solution because
the contains method returns as soon as a "not contained" word
is found.
As of Swift 4 or later, you can use allSatisfy:
let success = wordList.allSatisfy(text.contains)
A more Swifty solution that will stop searching after it found a non-existent word:
var text = "Hello Swift-world"
var textArray = ["Hello", "world"]
let match = textArray.reduce(true) { !$0 ? false : (text.range(of: $1) != nil ) }
Another way to do it which stops after it found a non-match:
let match = textArray.first(where: { !text.contains($0) }) == nil
Another possibility is regular expressions:
// *'s are wildcards
let regexp = "(?=.*Hello*)(?=.*world*)"
if let range = Text.range(of:regexp, options: .regularExpression) {
print("this string contains Hello world")
} else {
print("this string doesn't have the words we want")
}
I need to save files in an alphabetical order.
Now my code is saving files in numeric order
1.png
2.png
3.png ...
The problem is when i read this files again I read this files as described here
So I was thinking of changing the code and to save the files not in a numeric order but in an alphabetical order as:
a.png b.png c.png ... z.png aa.png ab.png ...
But in Swift it's difficult to increment even Character type.
How can I start from:
var s: String = "a"
and increment s in that way?
You can keep it numeric, just use the right option when sorting:
let arr = ["1.png", "19.png", "2.png", "10.png"]
let result = arr.sort {
$0.compare($1, options: .NumericSearch) == .OrderedAscending
}
// result: ["1.png", "2.png", "10.png", "19.png"]
If you'd really like to make them alphabetical, try this code to increment the names:
/// Increments a single `UInt32` scalar value
func incrementScalarValue(_ scalarValue: UInt32) -> String {
return String(Character(UnicodeScalar(scalarValue + 1)))
}
/// Recursive function that increments a name
func incrementName(_ name: String) -> String {
var previousName = name
if let lastScalar = previousName.unicodeScalars.last {
let lastChar = previousName.remove(at: previousName.index(before: previousName.endIndex))
if lastChar == "z" {
let newName = incrementName(previousName) + "a"
return newName
} else {
let incrementedChar = incrementScalarValue(lastScalar.value)
return previousName + incrementedChar
}
} else {
return "a"
}
}
var fileNames = ["a.png"]
for _ in 1...77 {
// Strip off ".png" from the file name
let previousFileName = fileNames.last!.components(separatedBy: ".png")[0]
// Increment the name
let incremented = incrementName(previousFileName)
// Append it to the array with ".png" added again
fileNames.append(incremented + ".png")
}
print(fileNames)
// Prints `["a.png", "b.png", "c.png", "d.png", "e.png", "f.png", "g.png", "h.png", "i.png", "j.png", "k.png", "l.png", "m.png", "n.png", "o.png", "p.png", "q.png", "r.png", "s.png", "t.png", "u.png", "v.png", "w.png", "x.png", "y.png", "z.png", "aa.png", "ab.png", "ac.png", "ad.png", "ae.png", "af.png", "ag.png", "ah.png", "ai.png", "aj.png", "ak.png", "al.png", "am.png", "an.png", "ao.png", "ap.png", "aq.png", "ar.png", "as.png", "at.png", "au.png", "av.png", "aw.png", "ax.png", "ay.png", "az.png", "ba.png", "bb.png", "bc.png", "bd.png", "be.png", "bf.png", "bg.png", "bh.png", "bi.png", "bj.png", "bk.png", "bl.png", "bm.png", "bn.png", "bo.png", "bp.png", "bq.png", "br.png", "bs.png", "bt.png", "bu.png", "bv.png", "bw.png", "bx.png", "by.png", "bz.png"]`
You will eventually end up with
a.png
b.png
c.png
...
z.png
aa.png
ab.png
...
zz.png
aaa.png
aab.png
...
Paste this code in the playground and check result. n numbers supported means you can enter any high number such as 99999999999999 enjoy!
you can uncomment for loop code to check code is working fine or not
but don't forget to assign a lesser value to counter variable otherwise Xcode will freeze.
var fileName:String = ""
var counter = 0.0
var alphabets = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]
let totalAlphaBets = Double(alphabets.count)
let numFiles = 9999
func getCharacter(counter c:Double) -> String {
var chars:String
var divisionResult = Int(c / totalAlphaBets)
let modResult = Int(c.truncatingRemainder(dividingBy: totalAlphaBets))
chars = getCharFromArr(index: modResult)
if(divisionResult != 0){
divisionResult -= 1
if(divisionResult > alphabets.count-1){
chars = getCharacter(counter: Double(divisionResult)) + chars
}else{
chars = getCharFromArr(index: divisionResult) + chars
}
}
return chars
}
func getCharFromArr(index i:Int) -> String {
if(i < alphabets.count){
return alphabets[i]
}else{
print("wrong index")
return ""
}
}
for _ in 0...numFiles {
fileName = getCharacter(counter: counter)+".png"
print(fileName)
counter += 1
}
fileName = getCharacter(counter: Double(numFiles))+".png"
print(fileName)
func updateTotalScore() -> Int {
var totalScoreDefault = NSUserDefaults.standardUserDefaults()
var highScoreAB1 = defaults.integerForKey("highScoreAB1")
var highScoreAB2 = defaults.integerForKey("highScoreAB2")
var highScoreAB3 = defaults.integerForKey("highScoreAB3")
var highScoreAB4 = defaults.integerForKey("highScoreAB4")
var highScoreAB5 = defaults.integerForKey("HighScoreAB5")
var highScoreAB6 = defaults.integerForKey("highScoreAB6")
var highScoreAB7 = defaults.integerForKey("highScoreAB7")
totalScoreDefault =
(defaults.integerForKey("highScoreAB1") + defaults.integerForKey("highScoreAB2")) + (defaults.integerForKey("highScoreAB3") + defaults.integerForKey("highScoreAB4")) + (defaults.integerForKey("highScoreAB5") + defaults.integerForKey("highScoreAB6")) + defaults.integerForKey("highScoreAB7") }
Adding multiple keys to get a total score default throws the following error. I tried grouping them together into pairs, and that did not work. Thank you in advance. This is a continuation from a post from yesterday.
Just as an addition to Logan's answer, because you are saying that you have problems with "complex expression" compiler error. This should compile:
func updateTotalScore() -> Int {
let defaults = NSUserDefaults.standardUserDefaults()
let totalScoretDefault =
defaults.integerForKey("highScoreAB1") +
defaults.integerForKey("highScoreAB2") +
defaults.integerForKey("highScoreAB3") +
defaults.integerForKey("highScoreAB4") +
defaults.integerForKey("highScoreAB5") +
defaults.integerForKey("highScoreAB6") +
defaults.integerForKey("highScoreAB7")
return totalScoretDefault
}
It looks like you are trying to add all of the highscores up into one UserDefault named totalScoreDefault. If so, you need to be setting the totalScoreDefault like so:
default.setInteger(highScoreAB1 + ... + highScoreAB7, forKey: "totalScoreDefault")
// You can also consider adding all highScores up before
// this to make the setInteger portion look cleaner.
var totalScore = 0
for var i = 1; i < 8; i++ {
totalScore += defaults.integerForKey("highScoreAB\(i)")
}
defaults.setInteger(totalScore, forKey: "totalScoreDefault")
I would like to print the result of the bool value
When I do it I have "true" instead the amount.
I know it probably sounds really stupid but I'm just getting started with swift
var monthsWeek:Int?
var hoursWageHours:Double = 14.47
let months4WeeksHours:Double = 156.00
let months5WeeksHours:Double = 195.00
var normalpay:Double = 0
let months5weeks:Bool = true
let months4weeks:Bool = true
if months5weeks {
normalpay = hoursWageHours * months5WeeksHours
if months4weeks {
normalpay = hoursWageHours * months4WeeksHours
}
}
or woud that make more sence even if didnt print the result still
var monthsWeek:Int?
var hoursWageHours:Double = 14.47
let months4WeeksHours:Double = 156.00
let months5WeeksHours:Double = 195.00
var normalpay:Double = 0
if monthsWeek == 195 {
normalpay = hoursWageHours * months5WeeksHours
if monthsWeek == 4 {
normalpay = hoursWageHours * months4WeeksHours
}
}
monthsWeek = 4
I came here looking for an actual print of a bool. It turns out you can do this:
var a_bool = false
print("a_bool is ")
println(a_bool)
And you can do this with ints:
var a_int = 42
println("This is an int " + String(a_int))
You can't do this with bools though. However you can do:
println("This is a bool " + String(stringInterpolationSegment: a_bool))
This is the closet I can come up with for something like this:
println("a_bool is ", a_bool) // does not work
println("a_bool is " + a_bool) // also does not work
Later on, I learned you can use \(variable) embedding like this:
println("This is an int \(a_int)")
A boolean variable can take only 2 values (true or false).
So it is logical that when you print it you have true or false.