Why might simple changes to code fail to update? The 'hot code replace' message appears as usual when making big changes, but changing a println string, or commenting out a method call sometimes does nothing, and the app has to be restarted to apply the change. I think it may have something to do with native calls, but other than that there seems no pattern to it.
If you are not introducing changes that affect the class signature as Stephen mentioned, it should work. If it's not working, makesure that you have enabled 'Build Automatically' for the project (Project -> Build Automatically).
This is required for Eclipse to perform local builds when you do changes and push those to the server when you make a change.
Hot code replace does not allow you to change a class signature. That means, no attribute changes, no adding or removing methods, etc.
What you are allowed to do is to change a method's implementation.
Related
I am using Eclipse IDE for Java Developers
Version: Helios Service Release 1
Build id: 20100917-0705
In remote debugging Web app with tomcat 7.0.37, when I make some changes, even a line, the changes can not be made into the runtime, so I need to recompile and re-deploy the war application. Wast a lot of time. The message:
Hot code replace failed - Delete method not implemented
I do not understand the message.
Anyone know the secret on how to auto reflect the code change in debug mode? Thanks.
I've found that for hot code replacement to work the code being modified/replaced must be in the execution stack. So you can hot replace changes made to a method you've stopped in, but you can't hot replace changes to that method once you step out of that method... unless you first stop back in the method on a successive call to the method.
With the standard JVM (Oracle's), you can only modify existing methods. Both adding and deleting methods, and changing structure of class (moving methods, fields) are NOT supported. For that, go to JRebel!
One thing to notice is that changes to seemingly "normal code" inside some method will actually need for the java compiler to add or delete methods - and hence it will fail. This happens e.g. if you in an inner class accesses private fields in the outer class - the java compiler will need to add synthetic accessor-methods to the outer class to let the inner class access those fields - which hence will fail to Hot Code Replace. Also, if you remove some code accessing such fields, the java compiler wants to remove the corresponding synthetic accessor-method, which also will fail.
I think there is no way to reflect the code change in debug mode
Debug mode is to trace program flow and find if any issues or errors at particular piece of code....
it just points to line of code in eclipse, which is running in your tomcat, ie. code in eclipse is not used to run application the code u have installed or put in tomcat runs
hence your changes made in eclipse cant reflect in tomcat code
I sometimes make use of projection classes (subclasses of %Projection.AbstractProjection) to generate various things, and I'm finding that if I use the %Dictionary classes to modify other classes from within the CreateProjection method, the changes make it into ^oddDEF correctly, the changed classes compile and run correctly, but Cache Studio doesn't see the changes, and keeps displaying them the way they were prior to modification. If I then compile from Cache Studio, it overwrites the changes made by the projection class.
It's fairly "sticky" - if I close the changed classes, remove them from my project, then add them back and open them, the unchanged, cached version is still there in Cache Studio.
I am calling QueueClass on the changed classes, but that doesn't seem to matter. I'm on 2008.2, in case that matters.
How can I programatically get Cache Studio to update its cache, or otherwise fix this problem in a reasonable way (closing Cache Studio each time isn't really reasonable, for example)?
Try to reset TimeChanged property of %Dictionary.ClassDefinition
What does it do exactly? Can't find an explanation in plain language
Basically it erases all compiled components, so the next build will build everything fresh. This in theory should never be necessary, since we all know that IDEs are perfect and totally keep track of all source changes and hence know precisely what components need recompiling/rebuilding at any given time. (But, of course, such perfection seems to be a bit elusive.)
The concept of "clean" is found in most IDEs. You use it when things are behaving strangely, or in certain known cases where a "clean" rebuild is required.
A very important usage for "Clean" is when you have images in your application and you update their contents without changing their name. For example say you have an image named Background.png that you used for a while, then you edited this picture in Photoshop and saved the new one in the same name. On the next run of the app the image will not be refreshed; the compiler will continue to show the old one. To make sure to see the updated image you need to do "Clean" before you run. So in principle on all image updates where the name did not change you need to "Clean".
By the way, you might need to "Clean" once for the simulator and once for the real device run. One final note, don't have the idea in mind that every time you write code that you think should work but don't work as you expect then the solution is "Clean", in such a case it is always a problem in your code which needs revision.
I have recently come across the LESS Leaner CSS a template engine for CSS based on ruby. The idea sounded neat, but in practice we need to compile the program to get CSS. This is cumbersome as we make too many changes while working on CSS and for every edit we don't want to compile.
In Eclipse, there are "Save-Actions" but it handles only formatting changes.
Is there a way on saving the file in Eclipse, to call or trigger the compilation?
Its easy to do this in Vi or Emacs.
I think all you need is to define a custom Builder for your project. That way, you can run a program or an ant script whenever certain files change.
Right click on the project -> Properties -> Builders -> New
While the Builders are a good solution, keep in mind they only work when a build is issued - either using auto-build or using a manual build which is invoked, well, manually. If you are looking for something that will operate after a save, regardless of the auto-build state you will need to write a plugin which listens to resource changes in Eclipse.
You do that by creating a workspace change listener and installing it like that:
ResourcesPlugin.getWorkspace().addResourceChangeListener(
..., IResourceChangeEvent.POST_CHANGE);
I'm sure you can take it from here :-)
Have any other iPhone developers experienced this phenomenon? I can see his contributions in xCode - I see for example my colleague has wrapped a navigation controller around one of my view controllers and added it to my tab bar. Great! That view really did call for a navigation controller and this is a welcome addition to the project.
So, I up my code and compile - no navigation controller. I do build -> clean all targets, thinking maybe some pre-compiled code is mucking me up and compile again. Same result. I was eventually able to get his changes to compile by deleting the whole directory and checking it out from the repository, but I really don't want to do that every time my colleague checks in code.
Is there some kind of box I need to check or something? What could be causing this behavior?
Thanks in advance.
Here are a number of possible fixes:
1) Delete the current version of your app off the simulator and/or device. This especially becomes necessary when using Default.png or app icons. There are a lot of shortcuts that the compiler takes for apps that are already "installed".
2) Make sure that there are NEVER any build folders or user specific files (pbuser.USERNAME I think). These files wrecked havoc on a few projects and we basically had to delete and start over.
3) Make sure that all files are svn added to the project before each commit (although this wouldn't matter for your current problem.
4) Find the changed code and set breakpoints for the debugger to catch. I believe that breakpoints that turn YELLOW while running signify that there is a difference between run and code.
I would tend to believe that it would be a problem with the .proj file also, but it sounds like that's not it.
Some things to check (but maybe you already did it):
is the new code added to the correct target? You will still see it in the project tree, but it won't be compiled
if you are using a SVN (or CVS) client that is not XCode, you have to remember to commit (and update) the .xcodeproject file too.
Your question isn't entirely clear to me, so forgive these follow-up questions:
Where in Xcode did you see the changes? In the repository browser, or in the file browser part of Xcode?
What do you mean by "up your code"? (I'm assuming you mean that you chose the "Update source from repository" option or whatever it is called - I'm away from my mac right now - but I thought I'd check.)