unwrap optionals #2698

russellbstephens · 2017-08-09T21:19:53Z

an attempt to reduce the number of force unwraps

codecov-io · 2017-08-09T23:19:40Z

Codecov Report

Merging #2698 into master will increase coverage by 0.05%.
The diff coverage is 9.56%.

@@            Coverage Diff             @@
##           master    #2698      +/-   ##
==========================================
+ Coverage   19.64%   19.69%   +0.05%     
==========================================
  Files         113      113              
  Lines       13792    13720      -72     
==========================================
- Hits         2709     2702       -7     
+ Misses      11083    11018      -65

Impacted Files	Coverage Δ
Source/Charts/Charts/RadarChartView.swift	`0% <0%> (ø)`	⬆️
Source/Charts/Components/MarkerImage.swift	`0% <0%> (ø)`	⬆️
Source/Charts/Animation/Animator.swift	`1.44% <0%> (+0.15%)`	⬆️
Source/Charts/Charts/PieRadarChartViewBase.swift	`0% <0%> (ø)`	⬆️
Source/Charts/Charts/CombinedChartView.swift	`0% <0%> (ø)`	⬆️
...ata/Implementations/Standard/BubbleChartData.swift	`0% <0%> (ø)`	⬆️
...ta/Implementations/Standard/ScatterChartData.swift	`0% <0%> (ø)`	⬆️
...s/Data/Implementations/Standard/BarChartData.swift	`3.7% <0%> (+0.06%)`	⬆️
...ta/Implementations/Standard/LineChartDataSet.swift	`24.19% <0%> (+1.8%)`	⬆️
...a/Implementations/Standard/BarChartDataEntry.swift	`2.3% <0%> (ø)`	⬆️
... and 5 more

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liuxuan30 · 2017-08-11T08:32:45Z

Mind to give some details and what this for?

russellbstephens · 2017-08-11T17:01:26Z

I was just looking through the repo and noticed some areas that could be refactored to remove !. Overall it adds a more swifty feel to your codebase

pmairoldi · 2017-09-07T04:13:12Z

Thanks for the submission. Moving to a more swift style is great. I've wanted to do that myself but hadn't had the time. I'd like to merge this change after swift 4 support is merge. Should be soon.

jjatie · 2017-09-10T22:05:33Z

Source/Charts/Charts/BarLineChartViewBase.swift

            {
                foundScrollView = nil
            }

            var scrollViewPanGestureRecognizer: NSUIGestureRecognizer!

-            if foundScrollView !== nil


replace the loop with

let scrollViewPanGestureRecognizer = foundScrollView?.nsuiGestureRecognizers?.first { $0 is NSUIPanGestureRecognizer }

I'm not confident in using .first here to achieve the same effect

Why not? The code you've replaced the for loop with is not the same. In the for loop, we escape after we find the first NSUIPanGestureRecognizer, in your code it will continue to loop through and find more.

Rather than leave it the old way (using our own implementation of first) why not simply use the built-in method and replace 5 lines with 2 more explicit lines.

jjatie · 2017-09-10T22:09:09Z

Source/Charts/Charts/ChartViewBase.swift

@@ -562,12 +561,12 @@ open class ChartViewBase: NSUIView, ChartDataProvider, AnimatorDelegate
        {
            if h == nil
            {
-                delegate!.chartValueNothingSelected?(self)
+                delegate?.chartValueNothingSelected?(self)


Why leave delegate != nil in the if statement if you're going to use optional chaining?
Maybe
if callDelegate, let delegate = delegate { ... } instead?

jjatie · 2017-09-10T22:10:02Z

Source/Charts/Charts/ChartViewBase.swift

@@ -562,12 +561,12 @@ open class ChartViewBase: NSUIView, ChartDataProvider, AnimatorDelegate
        {
            if h == nil


To follow the spirit of your PR, you should flip the order of the if-else, i.e.

if let h = h { ... } else { ... }

jjatie · 2017-09-10T22:14:53Z

@russellbstephens I'd encourage you to look at PR #2737. It takes this a lot further and reduces many algorithms to one-liners. Perhaps you could bring some of those changes into here, as currently I can't get that PR to build.

russellbstephens · 2017-09-16T17:24:39Z

@jjatie sure no problem, I put this up to see if you all would be interested in cleaning up the code a bit. Now that I know there is interest, I would be happy to go further with this

russellbstephens · 2017-09-16T17:33:57Z

@jjatie after looking at #2737 I feel you should be able to resolve the conflicts and get it into running order, as these two refactors are separate with different goals

russellbstephens · 2017-09-27T19:15:48Z

@petester42 is this ready to go in?

liuxuan30 · 2017-10-08T01:52:23Z

sorry to jump in. Is this on swift 4 or need another convert on your side?

liuxuan30 · 2017-10-08T02:06:09Z

Source/Charts/Charts/ChartViewBase.swift

@@ -888,7 +887,7 @@ open class ChartViewBase: NSUIView, ChartDataProvider, AnimatorDelegate

        do
        {
-            try imageData.write(to: URL(fileURLWithPath: path), options: .atomic)
+            try imageData?.write(to: URL(fileURLWithPath: path), options: .atomic)


Optional chaining can cover up the exception if the image type is not supported?

liuxuan30 · 2017-10-08T02:19:56Z

Source/Charts/Charts/CombinedChartView.swift

@@ -120,7 +120,7 @@ open class CombinedChartView: BarLineChartViewBase, CombinedChartDataProvider
            {
                return nil
            }
-            return (_data as! CombinedChartData!).lineData


It has been sometime we review this part. But seems CombinedChartData! can be CombinedChartData now,

liuxuan30 · 2017-10-08T02:19:57Z

Source/Charts/Charts/CombinedChartView.swift

@@ -120,7 +120,7 @@ open class CombinedChartView: BarLineChartViewBase, CombinedChartDataProvider
            {
                return nil
            }
-            return (_data as! CombinedChartData!).lineData
+            return (_data as? CombinedChartData)?.lineData


shall we use (_data as! CombinedChartData) or (_data as? CombinedChartData)? ? seems as! is safe here though as? is safer

I want to avoid using !, since in a case where _data === nil ! will crash

liuxuan30 · 2017-10-08T02:24:35Z

Source/Charts/Charts/CombinedChartView.swift

@@ -55,7 +55,7 @@ open class CombinedChartView: BarLineChartViewBase, CombinedChartDataProvider

            self.highlighter = CombinedHighlighter(chart: self, barDataProvider: self)

-            (renderer as! CombinedChartRenderer?)!.createRenderers()
+            (renderer as? CombinedChartRenderer)?.createRenderers()


old code is a bit weird (maybe the compiler bug). But if it's safe unwrap here, why not use (renderer as! CombinedChartRenderer).createRenderers()? renderer has been setup as combined chart renderer in initialize() above.

I'd rather not rely on the assumption renderer !== nil

I agree with @russellbstephens because while the three of us may know it's safe to force unwrap here, it is in no way clear that this is the case. I think a future ticket should involve making renderer a required property since you can't really do anything with a chart without a renderer.

liuxuan30 · 2017-10-08T02:26:07Z

Source/Charts/Charts/PieChartView.swift

@@ -104,16 +104,16 @@ open class PieChartView: PieRadarChartViewBase
        let optionalContext = NSUIGraphicsGetCurrentContext()
        guard let context = optionalContext else { return }

-        renderer!.drawData(context: context)
+        renderer?.drawData(context: context)


why ? here and below?

its best to avoid ! in swift

liuxuan30 · 2017-10-08T02:28:33Z

Source/Charts/Charts/PieRadarChartViewBase.swift

-                let touchLocation = touch?.location(in: self)
-
-                processRotationGestureBegan(location: touchLocation!)
+                if let touch = touches.first {


I'm not sure why use if here. Any ideas?

liuxuan30 · 2017-10-08T02:30:45Z

Source/Charts/Data/Implementations/Standard/BarChartDataEntry.swift

@@ -102,17 +102,17 @@ open class BarChartDataEntry: ChartDataEntry

    open func sumBelow(stackIndex :Int) -> Double
    {
-        if _yVals == nil
+        guard let _yVals = _yVals else


shall we keep using _ for local instant here? seems a little bit weird, though we don't have to change other code.

russellbstephens · 2017-11-06T15:05:32Z

is there any hope of this going in?

jjatie · 2017-11-06T15:20:33Z

Source/Charts/Animation/Animator.swift

@@ -115,9 +103,9 @@ open class Animator: NSObject
                elapsed = duration
            }

-            if _easingX != nil
+            if let _easingX = _easingX


Why isn't this one line?
phaseX = _easingX?(elapsed, duration) ?? Double(elapsed / duration)

jjatie · 2017-11-06T15:20:57Z

Source/Charts/Animation/Animator.swift

            {
-                phaseY = _easingY!(elapsed, duration)


This can be one line as well.

jjatie · 2017-11-06T15:28:00Z

Source/Charts/Charts/BarLineChartViewBase.swift

@@ -233,7 +233,7 @@ open class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChartD

        context.restoreGState()

-        renderer!.drawExtras(context: context)


Why not use
guard let data = data, let renderer = renderer else { return }
at the beginning of the function?

Logically, a draw() function would require a renderer to draw anything, and looking through the implementation of the function this is true.

jjatie · 2017-11-06T15:30:38Z

Source/Charts/Charts/BarLineChartViewBase.swift

@@ -533,7 +533,7 @@ open class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChartD

            let h = getHighlightByTouchPoint(recognizer.location(in: self))

-            if h === nil || h!.isEqual(self.lastHighlighted)
+            if h === nil || h?.isEqual(self.lastHighlighted) ?? false


this can be just if h?.isEqual(self.lastHighlighted) ?? true { because we want to enter the if statement if h == nil

The former force unwrapping was also acceptable, because if the first condition passed on the or statement, we would have already entered the if statement.

jjatie · 2017-11-06T15:46:46Z

Source/Charts/Charts/BarLineChartViewBase.swift

@@ -753,7 +753,7 @@ open class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChartD

                if ((h === nil && lastHighlighted !== nil) ||
                    (h !== nil && lastHighlighted === nil) ||
-                    (h !== nil && lastHighlighted !== nil && !h!.isEqual(lastHighlighted)))
+                    (h !== nil && lastHighlighted !== nil && !(h?.isEqual(lastHighlighted) ?? false)))


Here we've already checked that h != nil in the AND statement. If h == nil escape early from the AND statement, so it is safe to force unwrap h

Alternatively, we can do the same thing as before and write
lastHighlighted !== nil && !(h?.isEqual(lastHighlighted) ?? true)

Currently there is an issue in the last statement. If the whole expression was evaluated, then in the last component (!(h?.isEqual(lastHighlighted) ?? false)) you would return true when h == nil which is not what we want.

jjatie · 2017-11-06T15:51:13Z

Source/Charts/Charts/BarLineChartViewBase.swift

@@ -931,7 +931,7 @@ open class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChartD
            ))
        {
            var scrollView = self.superview
-            while (scrollView !== nil && !scrollView!.isKind(of: NSUIScrollView.self))
+            while (scrollView !== nil && !(scrollView?.isKind(of: NSUIScrollView.self) ?? false))


Same issue here where if the last component is evaluated and scrollView == nil we return true
Easiest way to solve this is to replace
(scrollView !== nil && !(scrollView?.isKind(of: NSUIScrollView.self) ?? false))
with
!(scrollView?.isKind(of: NSUIScrollView.self) ?? true)

jjatie · 2017-11-06T15:59:47Z

Source/Charts/Charts/ChartViewBase.swift

-        // if no position specified, draw on default position
-        if position == nil
-        {
+        let position: CGPoint


Could be cleaner to do this.

let p = description.position ?? CGPoint(x: bounds.width - _viewPortHandler.offsetRight - description.xOffset, y: bounds.height - _viewPortHandler.offsetBottom - description.yOffset - description.font.lineHeight)

Might just come down to preference.

jjatie · 2017-11-06T16:02:22Z

Source/Charts/Charts/ChartViewBase.swift

+        let position: CGPoint
+        if let descriptionPosition = description.position {
+            position = descriptionPosition
+        } else {
            let frame = self.bounds


It's generally good practice to short a variable call (i.e. let width = self.frame.size.width), but in this case it is unnecessary and wrong. Unnecessary because you don't need to explicitly state self, and wrong because in Cocoa frame and bounds mean two different things. frame should have never been here in the first place.

So we can just write

CGPoint(x: bounds.width - _viewPortHandler.offsetRight - description.xOffset, y: bounds.height - _viewPortHandler.offsetBottom - description.yOffset - description.font.lineHeight)

jjatie · 2017-11-06T16:13:37Z

Source/Charts/Charts/PieRadarChartViewBase.swift

-            let touchLocation = touch?.location(in: self)
-
-            processRotationGestureMoved(location: touchLocation!)
+            if let touch = touches.first {


Can we move the if let touch = touches.first into if rotationEnabled && !rotationWithTwoFingers
i.e.

if rotationEnabled && !rotationWithTwoFingers, let touch = touches.first { ... }

Actually, we don't need to check to see if touches.first is non-nil. We know there is at least one touch because the delegate method is called. Even Apple force unwraps this their sample code.

jjatie · 2017-11-06T16:15:54Z

Source/Charts/Charts/PieRadarChartViewBase.swift

-            let touchLocation = touch?.location(in: self)
-
-            processRotationGestureEnded(location: touchLocation!)
+            if let touch = touches.first {


Same as previous comment

jjatie · 2017-11-06T16:17:18Z

Source/Charts/Charts/RadarChartView.swift

@@ -118,19 +118,19 @@ open class RadarChartView: PieRadarChartViewBase

        if drawWeb
        {
-            renderer!.drawExtras(context: context)
+            renderer?.drawExtras(context: context)


guard let data = _data, let renderer = renderer else { return } at the beginning of the function,

jjatie · 2017-11-06T16:18:52Z

Source/Charts/Components/MarkerImage.swift

@@ -102,7 +102,7 @@ open class MarkerImage: NSObject, IMarker
            height: size.height)

        NSUIGraphicsPushContext(context)
-        image!.draw(in: rect)
+        image?.draw(in: rect)


Seems like there should be a guard let image = image else { return } at the beginning of the method. Drawing will do nothing if image == nil

jjatie · 2017-11-06T16:19:58Z

Source/Charts/Components/MarkerView.swift

@@ -36,18 +36,18 @@ open class MarkerView: NSUIView, IMarker
        {
            offset.x = -point.x
        }
-        else if chart != nil && point.x + width + offset.x > chart!.bounds.size.width
+        else if let chart = chart, point.x + width + offset.x > chart.bounds.size.width


guard let chart = chartView else { return } at the beginning.

this func must return a CGPoint

guard let chart = chartView else { return offset }

jjatie · 2017-11-06T16:34:29Z

Source/Charts/Data/Implementations/Standard/BarChartDataEntry.swift

@@ -102,17 +102,17 @@ open class BarChartDataEntry: ChartDataEntry

    @objc open func sumBelow(stackIndex :Int) -> Double
    {
-        if _yVals == nil
+        guard let yVals = _yVals else


Throughout the project we're being inconsistent in how we write closures. Sometimes we open the closure on a new line, sometimes not, and sometimes we write one liners. Since you're going through a significant portion of the project already, can we consolidate on a format?

I would love too, personally I think opening on the same line is fine

jjatie · 2017-11-06T16:35:17Z

Source/Charts/Data/Implementations/Standard/BubbleChartData.swift

@@ -27,8 +27,7 @@ open class BubbleChartData: BarLineScatterCandleBubbleChartData
    /// Sets the width of the circle that surrounds the bubble when highlighted for all DataSet objects this data object contains
    @objc open func setHighlightCircleWidth(_ width: CGFloat)
    {
-        for set in (_dataSets as? [IBubbleChartDataSet])!
-        {
+        (_dataSets as? [IBubbleChartDataSet])?.forEach { set in


Could be a one liner as
(_dataSets as? [IBubbleChartDataSet])?.forEach { $0.highlightCircleWidth = width }

russellbstephens · 2017-11-06T18:58:07Z

@jjatie how's it looking?

jjatie · 2017-11-06T19:05:29Z

Looks fine to me!

russellbstephens · 2017-11-06T20:22:09Z

nice!

russellbstephens · 2017-11-09T14:13:11Z

so merge?

russellbstephens · 2017-11-09T14:13:19Z

:)

jjatie · 2017-11-09T15:12:18Z

@liuxuan30

liuxuan30 · 2017-11-10T03:46:27Z

seems I don't have further questions. @danielgindi @petester42, any comments?

pmairoldi · 2017-11-15T02:22:31Z

The review that has been done by everyone seems adequate to me.

liuxuan30 · 2017-11-15T02:30:43Z

ok, merging.

russellbstephens force-pushed the cleanup branch from 6573132 to 7d8ec67 Compare August 9, 2017 22:42

jjatie reviewed Sep 10, 2017

View reviewed changes

liuxuan30 reviewed Oct 8, 2017

View reviewed changes

russellbstephens force-pushed the cleanup branch from e2fecde to 4f9f5c2 Compare October 15, 2017 22:54

jjatie reviewed Nov 6, 2017

View reviewed changes

Russell Stephens added 7 commits November 6, 2017 15:27

unwrap optionals

115c857

unwrap delegate

d25b005

unwrap h

dd32a87

remove underscore from local constant

5b08caf

updates from code review

b98bf67

more cleanup

4ffbec1

add guard

83ec416

russellbstephens force-pushed the cleanup branch from 83ed464 to 83ec416 Compare November 6, 2017 20:27

liuxuan30 merged commit fc22a27 into ChartsOrg:master Nov 15, 2017

jjatie mentioned this pull request Nov 15, 2017

Minor changes to Animator #3005

Merged

russellbstephens deleted the cleanup branch November 19, 2017 14:54

		@@ -562,12 +561,12 @@ open class ChartViewBase: NSUIView, ChartDataProvider, AnimatorDelegate
		{
		if h == nil

		@@ -233,7 +233,7 @@ open class BarLineChartViewBase: ChartViewBase, BarLineScatterCandleBubbleChartD

		context.restoreGState()

		renderer!.drawExtras(context: context)

unwrap optionals #2698

unwrap optionals #2698

Conversation

russellbstephens commented Aug 9, 2017 • edited Loading

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liuxuan30 commented Aug 11, 2017

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jjatie commented Sep 10, 2017

russellbstephens commented Sep 16, 2017

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