Lets consider you have a sample JSON as shown belowhttps://gist.github.com/kmdarshan/cfa6a940268f7091faf886ed63b3b559 You can make use of Codable Library (https://developer.apple.com/documentation/swift/codable) in Swift to read and write data from a JSON. Firstly you need to map your data from the JSON onto a Struct as shown below. Once you have done that, its easy to read it using
View the code on Gist.
View the code on Gist.
View the code on Gist.
Sometimes using storyboard to do your alignment is easier than doing it via code. Here are the steps. Select all the icons, you want to add to the stack view. Click on the Embed in StackView at the bottom of the Xcode editor. Refer video.
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If you observe the output below, you will see that the progressive, repeated fields , single frame and multiple frame have values in them. This should give you an idea that it’s an interlaced video. Also most interlaced videos will have an ‘i’ in them. e.g. 1080i
Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. If there is no such substring, return the empty string “”. The testcases will be generated such that the answer is unique. A substring is a contiguous sequence of characters within the string. Example 1: Input: s = “ADOBECODEBANC”, t = “ABC”
The median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value and the median is the mean of the two middle values. For example, for arr = [2,3,4], the median is 3. For example, for arr = [2,3], the median is (2 + 3) / 2 = 2.5.
Largest Triple Products You’re given a list of n integers arr[0..(n-1)]. You must compute a list output[0..(n-1)] such that, for each index i (between 0 and n-1, inclusive), output[i] is equal to the product of the three largest elements out of arr[0..i] (or equal to -1 if i < 2, as arr[0..i] then includes fewer
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Send a notification from Objective C to React Native. Follow the link below to see how you can send a notification from Javascript to Objective-C and then back again to JS front end. View the code on Gist.
Drag and drop In iOS 11 https://en.wikipedia.org/wiki/Apple_File_System app store multiple days / user reviews iOS 11 – 64bit only. 32 bit apps not supported anymore High sierra last release to support 32bit release Jan 2018 – 64bit only app store Xcode 9 is much faster Semantic highlight – useful for functions opening and closing braces
If you have multiple targets use config files. This is the way to create them. Below is a sample of what you can specify in the config files. ARCHS = arm64 CLANG_CXX_LANGUAGE_STANDARD = gnu++98 CLANG_CXX_LIBRARY = libstdc++ LD_NO_PIE = NO OTHER_LDFLAGS = -Wl,-warn_compact_unwind HEADER_SEARCH_PATHS = ../code/ FRAMEWORK_SEARCH_PATHS = ../debug One of the things you can
Goto https://software.intel.com/en-us/articles/intel-ipp-legacy-libraries and download the links for your OS. Then follow the installation text file inside the zipped file. The password is specified in the installation file. Once downloaded extract the headers and libs into the proper folder. e.g. /opt/intel/include…
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As you can see in the above video, the last row of the photos is getting cut by the buttons. Ideally you would need to have the collection view scroll up, so that the last row is correctly visible. This can be done by setting the content offset programmatically. Today I would be showing
Always, when you set the constraints in auto layout in iOS, set the update option as shown in the pictures below : Also in most cases uncheck “Relative to margin” option.
Will KIF support targeting elements in WKWebView ? By now, you must have already known that KIF wouldn’t support accessing and tapping elements in WKWebView. This would surely cause a lot of problems for automation tests which were written to access UIWebView. [tester waitForViewWithAccessibilityLabel:@”SIGN IN”]; The above call will surely fail in WKWebView. In most
In your xcode settings, you might have seen the configurations as shown below: You can find the current configuration : xcodebuild -workspace test.xcworkspace -scheme “UXtests” -showBuildSettings You would use it in the code as follows : #ifdef TESTING // do something #endif But how would you apply the debug and testing configurations. These preprocessor statements
I have come across posts saying that the image doesn’t render on the iOS simulator. In order to generate an image, you get the pixels using this call. CIImage* ciImage = [CIImage imageWithCVPixelBuffer:pixelBuffer]; This will always fail on the simulator. The workaround to fix this would be creating a frame of your own, and then reading
How to do it ? +(Class)layerClass { return [CAEAGLLayer class] or [CAMetalLayer class]; } Why should you do it ? Your view draws content using Metal or OpenGL ES, in which case you would use a CAMetalLayer or CAEAGLLayer object. There is a specialized layer class that offers better performance. You want to take advantage
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Reason : You most likely have set the ownership permissions to 777 or something similar. .ssh folder must be set to 700. How to find out : Tail your logs. sudo tail -f /var/log/secure You can get warnings similar to this. Authentication refused: bad ownership or modes for directory /home/kmdarshan/.ssh. Solution : chmod 700 ~/.ssh chmod 600
TEsting Guidelines Define API requirements. It is important to define requirements and outcomes for each method or function that you add to your project. For requirements, include input and output ranges, exceptions thrown and the conditions under which they are raised, and the type of values returned (especially if the values are instances of classes).
Recently I was involved in a project, which involved converting all links from http to https, basically making the site SSL enabled. After we did the changes we needed to measure the performance of the pages. You can test this using a combination of techniques described here : a. Using chrome developer tools, you can
For threaded code, locks are one of the traditional ways to synchronize access to resources that are shared between threads. However, the use of locks comes at a cost. Even in the non-contested case, there is always a performance penalty associated with taking a lock. And in the contested case, there is the potential for
Different ways you can make use of blocks with examples. Hope it helps you get going with blocks :-). View the code on Gist.
Try running this simple experiment to see, how using autorelease pools can add up and save you tons of memory. I did, and it really helped. No autorelease pool for temporary objects: View the code on Gist. Memory Usage: View the code on Gist. Memory Usage:
I recently had to design a date picker, similar to the above but with custom text in it. For ex: the year component needs to have 2001,2000 and the string “no idea” in it as shown below. I could not use the default date picker since it doesn’t allow us to change the data source
I implemented some sample animations using UIKit Dynamics which are commonly used. e.g bringing a view down, pushing it up..etc. I have commented the code when needed. If you want more details look into the apple docs. View the code on Gist.
View the code on Gist. View the code on Gist.
Let’s consider this snippet of code: View the code on Gist. Using respondsToSelector: View the code on Gist. Obviously you can add additional checks, to see the kind of class, check the length and so on.
Lets consider this example, you need to customize your navigation bar, for text color, tint color and fonts. If you aren’t using UIAppearance, you would either do one of the following : subclass navigation bar/controller, set the changes in this class. change the settings every time you use the navigation controller. Now, lets consider if
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The treat app makes use of a wheel based selection menu. This is used for selecting occasions, photos and moods. I have tried to explain the reasoning behind the implementation of this, as shown below. If you want a sample implementation of this project its here: https://github.com/kmdarshan/wheel Below are some of the reasons, we had
This helps the user focus on the message with the background blacked out. Helps you get the message through. I just started using this for a project. I am planning on doing more customizations to this. Hosted here: https://github.com/kmdarshan/KMDAlertView
https://github.com/kmdarshan/LogIt
You can download the project here: https://github.com/kmdarshan/RRContacts
Click advanced on the login screen, and select “Use Old authentication protocol”. You should be able to connect, without any issues.
You would have probably learnt about using sprites from here http://www.w3schools.com/css/css_image_sprites.asp or somewhere else on the web. Many tutorials who have told you to use background positioning to position the sprite. This is somewhat correct, but you aren’t really thinking long term over here. If in the future, there is a change in the sprite generation
What’s wrong with the below code ? The reason it will crash, is because the enumeration doesn’t check the class type. If we get invalid data from the method, other than an array and pass it to this it will crash. The easiest way to fix this is as shown below :
If you don’t know about web workers learn them here: https://developer.mozilla.org/en-US/docs/Web/Guide/Performance/Using_web_workers Disclaimer: Might not follow strict coding standards, this is just a demo. This post basically shows how you can use webworkers to display a timer. For this I will be using the following files: a. index.php b. worker.js Inside your index.php, lets write some