Huge Respect for Ravi Sir, He is genius Guy, With the help of him videos related to an iOS , I was selected in reputed company , and now I have around 2year of experience and salary package is also great . all credit to Ravi sir. Salute to this man bcz I was selected in covid time and also I supported to my family with my earning. Again Really thanks from my heart. :)))
Super cool .. 👌👌 ... As always you are ... I have question here, Instead of direct initialise DispatchGroup can we create wrappper for it with Lazy and as per our need we can call in our code ? other question is, How can i setup swagger part for testing my API ? If possible need your support Thanks
You can create a wrapper for the DispatchGroup. Swagger Integration involves adding a package and configuring it. I am a dotnet developer to the core so integrating swagger is simple but if you're using a different stack, feel free to ask, and I can provide the specific steps. Additionally, you can refer to Swagger's official documentation for setup guidelines, as I'll also be using it as a reference.
Dispatch Group is blocked thread is there any other way for async api call with same scenario Please make video for other ways to do api calls handling
The dispatchGroup does not block your main thread and will perform the task concurrently, however using the wait( ) function of the DispatchGroup you may opt to wait synchronously else it won’t wait or block your threads If you don’t want to use DispatchGroup an alternative is operation queue
I don't understand how we can notify if we got an error? I'm calling network API call with Result type closure. if the case .success I'm appending the user and leaving the group. if case .failure do I need to use DispatchQueue.main.async? Also, how can I call the second API after I got the result of the first API?
Hi.. in my App i m hitting multiple Api's and saving there Json responce in Code Data but i m getting an error Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) so can you please tell how can i handle this error
Push your code on GitHub so that I can check what’s going on and why are we getting this error, there can be multiple reasons for this which can be identified looking at the code My id: codecat15 If you want to email then id is codecat15@gmail.com
haha majority from apple developer documentation :) aur kuch errors aur bugs bhi sikha dete hai, is topic pe kuch doubt hoga to puchna aur aapne iOS group k saath is video ko zaroor share karna
DG is pretty awesome in handling a group of task, do feel free to ask questions on this topic and do share the video with your iOS group and share the knowledge :)
Hello Rahul, Nice to see your all hard work on explaining all things about Swift and SwiftUI and most of your explanation outside the code. For the last couple of months, I am following all the videos till up to date. Many things now I clearly understand. Thank you. Well, please explain on concept of semaphore in GCD and as well as with Dispatch Queue Label. If possible, I am looking for an explanation about these also. Thanks in advance.
I am working on the threading topics as of now to complete some of the concepts which were long pending, I hope to cover them all and you should also see some swiftui and combine videos in between. Do share the video with your iOS group and My name is Ravi and not Rahul :)
This is really great Ravi since the day i started watching your videos , day to day im getting close to swift . please keep making videos more on regular basis . so that we can learn more n more from you .
Thank you so much for your kind words and support! I'm thrilled to hear that my videos have been helping you with Swift. I'll definitely continue to create more content regularly. Stay tuned for more!
Clean and neat way of handing multiple api calls on a screen. A thing to note here is when you have several different types of api calls, and assume if 1 of those calls don't return a response due to some issue ( say bug in server code), 1 dispatchQueue.leave() call will be missed out of n calls and even if remaining n-1 are executed, still there'll be no output on screen because dispatchGroup.notify() is not called unless the the number of enters match number of leave calls. This is the most important thing to be taken care of while using DispatchGroup.
There's one more way of handling that and I did that in the past for one of my friend, I am assuming it was using flatMap can't really remember need to revisit the code, you see the use case was even if one API fails you don't want to call the other APIs at all and I thought it was hard but then the solution turned out to be pretty short actually would create a video on that. You bring in a very interesting topic for conversation buddy and that indeed is a neat observation you got going there
It's hard to tell without seeing the code but I will take a random guess here this may happen if you create more threads and there's an undocumented limit on the number of threads we can create which is 64. OR perhaps you missed to make call to leave function of the dispatch group
@@CodeCat15 Thanks for replying. Dispatch Groups is unreliable and risky api to use. If any network calls doesn't give callback or if we have retries where callback called twice. App crashes. it relies on external factors. I would recommend devs to use Operations than DispatchGroups.
@@freekkarar204 It actually depends on how one implements it and a lot has to do with the tools that we are using like a hammer cannot be used where a needle is required. Dispatch group has a wait function and you can use that to wait till the time your operation returns you the response but make sure you are not waiting on the main thread. But then I always prefer using the highest level of abstraction if more control is required for my task which is the operation queue
very informative video sir, I like the way you created array of requests. Previously I tried to add the dispatch group but didn't add due to miss information. Thanks for clarifying everything.
Thanks for this video bro. I guess next topic will be on operation queues to handle dependencies. Also make a video on DispatchSemaphore and compare it with DispatchGroups. ✌🏻
You indeed are a mind reader Waseem, yes the next session is on operation queues they handle dependencies more elegantly as compared to DG. As of now am trying to cover most of the threading concepts which were not present in the channel by showing how they can solve common uses cases of our iOS project. Do share the video with your iOS group 😊 and feel free to ask questions on this topic
Sure I am going topic by topic next video will be on operation queues solving the second part of the problem which is dependency based requests and there’s also one more short video i plan to make using protocol oriented programming which is for multiple data sources for a single screen.
Its similar like OperationQueue adddependency. But via using dispatchgroup.leave() e can controll, at which point the task will be ended. Here Ravi has used api example which is best demonstration for the task
Thread sanitizer are used to detect any issues with the code that you write, mostly used in debugging memory related issues which you can fix, the only issue with enabling them is that they kind of make your build process a little slow coz they are analyzing your code but hey a slow build is better than a runtime crash
Am glad now you will be able to resolve them more elegantly using dispatch group. Do share the video with your iOS group and feel free to ask questions on this topic
Hey Nagaraj, dispatch group indeeds performs better than nested closure and I have made a quick video for this and released it just now so do check and let me know if you have any questions regarding the same Link: th-cam.com/video/HucU2jBQffc/w-d-xo.html
I am glad this video was helpful, do check out the second part of the video where we compare the performance of nested closure and dispatch group Link: th-cam.com/video/HucU2jBQffc/w-d-xo.html
What about thread safety here. Assuming we have 100 department for which we need to fetch data. The response of those data need to add into an array from different threads. Arrays are not thread safe will it not crash or create issue on data show.
Given that requirement fetching 100 records of department is just too much, data should always be fetched on-demand. If you fetch everything at once even the unwanted records you are just consuming space in the users phone that’s a bad system design. Having said that, the assumption you made on the approach is not foolproof and will fail if you just keep on storing everything in one giant array doesn’t matter what approach you go with it. Array gets big and soon the app runs out of memory or worse, who knows threading bugs are unpredictable man. 🤷♂️ Anyways, If you want to walk that path then maybe first try with groups see if it really fails, have a test case as a proof that it fails or not and then maybe you can use semaphores or barriers. I don’t usually recommend locks I always try to avoid them coz of their unpredictability. Dispatch group is not a silver bullet for every use case that we face but yes it surely will give you a good starting point. There are many classes in the dispatch framework and every class handles a different use case so choose your tools wisely.
Huge Respect for Ravi Sir, He is genius Guy, With the help of him videos related to an iOS , I was selected in reputed company , and now I have around 2year of experience and salary package is also great . all credit to Ravi sir. Salute to this man bcz I was selected in covid time and also I supported to my family with my earning. Again Really thanks from my heart. :)))
in this example, we are entering and leaving DG 2 times, so will notify called 2 times?
Super cool .. 👌👌 ... As always you are ...
I have question here, Instead of direct initialise DispatchGroup can we create wrappper for it with Lazy and as per our need we can call in our code ?
other question is, How can i setup swagger part for testing my API ? If possible need your support
Thanks
You can create a wrapper for the DispatchGroup.
Swagger Integration involves adding a package and configuring it. I am a dotnet developer to the core so integrating swagger is simple but if you're using a different stack, feel free to ask, and I can provide the specific steps. Additionally, you can refer to Swagger's official documentation for setup guidelines, as I'll also be using it as a reference.
Dispatch Group is blocked thread is there any other way for async api call with same scenario
Please make video for other ways to do api calls handling
The dispatchGroup does not block your main thread and will perform the task concurrently, however using the wait( ) function of the DispatchGroup you may opt to wait synchronously else it won’t wait or block your threads
If you don’t want to use DispatchGroup an alternative is operation queue
Sir dispatch group main ma chahta hoon k meri pahi query ka response jab aye tu tab dosri query update ho wo kase karain ge
For serial api call I have a video do check it out and let me know if that answers your question
Link: th-cam.com/video/II7bJmC64IY/w-d-xo.html
closure Nightmare XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD XD
I don't understand how we can notify if we got an error? I'm calling network API call with Result type closure. if the case .success I'm appending the user and leaving the group. if case .failure do I need to use DispatchQueue.main.async? Also, how can I call the second API after I got the result of the first API?
Very informative and explained in very simple way.
Hi.. in my App i m hitting multiple Api's and saving there Json responce in Code Data but i m getting an error
Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)
so can you please tell how can i handle this error
Push your code on GitHub so that I can check what’s going on and why are we getting this error, there can be multiple reasons for this which can be identified looking at the code
My id: codecat15
If you want to email then id is codecat15@gmail.com
bhai aap itna sara knowledge late kaha se ho...yaar
haha majority from apple developer documentation :) aur kuch errors aur bugs bhi sikha dete hai, is topic pe kuch doubt hoga to puchna aur aapne iOS group k saath is video ko zaroor share karna
never thought this scenario can be handled so easily with DG. Take a bow man. 👏
DG is pretty awesome in handling a group of task, do feel free to ask questions on this topic and do share the video with your iOS group and share the knowledge :)
Hello Rahul,
Nice to see your all hard work on explaining all things about Swift and SwiftUI and most of your explanation outside the code. For the last couple of months, I am following all the videos till up to date. Many things now I clearly understand. Thank you. Well, please explain on concept of semaphore in GCD and as well as with Dispatch Queue Label. If possible, I am looking for an explanation about these also. Thanks in advance.
I am working on the threading topics as of now to complete some of the concepts which were long pending, I hope to cover them all and you should also see some swiftui and combine videos in between. Do share the video with your iOS group and My name is Ravi and not Rahul :)
@@CodeCat15 Dont worry about the name he is watching you...😀😅
Thank you
Glad it was helpful Pramod
This is really great Ravi since the day i started watching your videos , day to day im getting close to swift . please keep making videos more on regular basis . so that we can learn more n more from you .
Thank you so much for your kind words and support! I'm thrilled to hear that my videos have been helping you with Swift. I'll definitely continue to create more content regularly. Stay tuned for more!
Clean and neat way of handing multiple api calls on a screen. A thing to note here is when you have several different types of api calls, and assume if 1 of those calls don't return a response due to some issue ( say bug in server code), 1 dispatchQueue.leave() call will be missed out of n calls and even if remaining n-1 are executed, still there'll be no output on screen because dispatchGroup.notify() is not called unless the the number of enters match number of leave calls. This is the most important thing to be taken care of while using DispatchGroup.
There's one more way of handling that and I did that in the past for one of my friend, I am assuming it was using flatMap can't really remember need to revisit the code, you see the use case was even if one API fails you don't want to call the other APIs at all and I thought it was hard but then the solution turned out to be pretty short actually would create a video on that. You bring in a very interesting topic for conversation buddy and that indeed is a neat observation you got going there
Dispatch Group Crash BUG IN CLIENT OF LIBDISPATCH: Too many nested calls to dispatch_group_enter().. Hi Ravi.. you know when this occurs
It's hard to tell without seeing the code but I will take a random guess here this may happen if you create more threads and there's an undocumented limit on the number of threads we can create which is 64. OR perhaps you missed to make call to leave function of the dispatch group
@@CodeCat15 Thanks for replying. Dispatch Groups is unreliable and risky api to use. If any network calls doesn't give callback or if we have retries where callback called twice. App crashes. it relies on external factors. I would recommend devs to use Operations than DispatchGroups.
@@freekkarar204 It actually depends on how one implements it and a lot has to do with the tools that we are using like a hammer cannot be used where a needle is required. Dispatch group has a wait function and you can use that to wait till the time your operation returns you the response but make sure you are not waiting on the main thread. But then I always prefer using the highest level of abstraction if more control is required for my task which is the operation queue
very informative video sir, I like the way you created array of requests. Previously I tried to add the dispatch group but didn't add due to miss information. Thanks for clarifying everything.
That’s awesome I am glad this was helpful Anil, plz do feel free to ask questions and do share this video with your iOS group on WhatsApp or Facebook
Thanks for this video bro. I guess next topic will be on operation queues to handle dependencies. Also make a video on DispatchSemaphore and compare it with DispatchGroups. ✌🏻
You indeed are a mind reader Waseem, yes the next session is on operation queues they handle dependencies more elegantly as compared to DG. As of now am trying to cover most of the threading concepts which were not present in the channel by showing how they can solve common uses cases of our iOS project. Do share the video with your iOS group 😊 and feel free to ask questions on this topic
great
Great video for multiple api call with clean code... Great work.
I am glad this was helpful, do ask questions on this topic and do share the channel with your iOS group.
can you put some light on Static Dispatch and Dynamic dispatch in any of your video?
Sure I am going topic by topic next video will be on operation queues solving the second part of the problem which is dependency based requests and there’s also one more short video i plan to make using protocol oriented programming which is for multiple data sources for a single screen.
Its similar like OperationQueue adddependency. But via using dispatchgroup.leave() e can controll, at which point the task will be ended. Here Ravi has used api example which is best demonstration for the task
love you bro
@codeCat what is the purpose of code sanitiser ?
Thread sanitizer are used to detect any issues with the code that you write, mostly used in debugging memory related issues which you can fix, the only issue with enabling them is that they kind of make your build process a little slow coz they are analyzing your code but hey a slow build is better than a runtime crash
Useful video
thanks sir really good video i am learn more ..
Hey Ramani, am glad this video was helpful 😊
Brother you are Amazing✌✌✌
Thank you so much bro 😀
My favourite TH-camr 👍👍👍👍 I have so much these scenarios in our app
Am glad now you will be able to resolve them more elegantly using dispatch group. Do share the video with your iOS group and feel free to ask questions on this topic
@@CodeCat15 yeah sure sure 👍
Performs better than nested closure?
Hey Nagaraj, dispatch group indeeds performs better than nested closure and I have made a quick video for this and released it just now so do check and let me know if you have any questions regarding the same
Link: th-cam.com/video/HucU2jBQffc/w-d-xo.html
Nice tutorial. Can you make video on multiple images upload along with other parameters using alamofire
This is what I was looking for. Thanks 😎
Glad you found it Rakesh, and I hope this video was helpful
Superb. Thanks Ravi
Great work sir 👍
Thank you Abdul
Niceeee
I am glad this video was helpful, do check out the second part of the video where we compare the performance of nested closure and dispatch group
Link: th-cam.com/video/HucU2jBQffc/w-d-xo.html
What about thread safety here. Assuming we have 100 department for which we need to fetch data. The response of those data need to add into an array from different threads. Arrays are not thread safe will it not crash or create issue on data show.
Given that requirement fetching 100 records of department is just too much, data should always be fetched on-demand.
If you fetch everything at once even the unwanted records you are just consuming space in the users phone that’s a bad system design.
Having said that, the assumption you made on the approach is not foolproof and will fail if you just keep on storing everything in one giant array doesn’t matter what approach you go with it.
Array gets big and soon the app runs out of memory or worse, who knows threading bugs are unpredictable man. 🤷♂️
Anyways, If you want to walk that path then maybe first try with groups see if it really fails, have a test case as a proof that it fails or not and then maybe you can use semaphores or barriers.
I don’t usually recommend locks I always try to avoid them coz of their unpredictability.
Dispatch group is not a silver bullet for every use case that we face but yes it surely will give you a good starting point.
There are many classes in the dispatch framework and every class handles a different use case so choose your tools wisely.
Awesome Bro 👍🏻