November 2012 - Pharo-users

Recovering Changes from a broken image
by Sven Van Caekenberghe Nov. 8, 2012

Nov. 8, 2012

Hi, One of the cool things of Smalltalk's images/changes file is that you can do a World Menu > Tools > Recover lost changesâ¦ to get back most [1] of your code in case your image/OS/machine suddenly crashed or you forgot to save your image or commit your Monticello packages. But we all have encountered the situation where the image is broken, saved in such a state that it no longer starts up properly. In that case your code might seem lost forever. No, it is not ! Two days ago I had this problem myself and I remembered something Marcus said some time ago: you can access the changes file of one (in casu your broken image) from another (working) image to select/recover the changes you want. It worked perfectly. The easiest procedure it to copy the .changes file from the broken image and rename its extension to .cs and then open it from a World Menu > Tools > File Browser and open a Changes browser on it. I found this very useful. This is a really important technique to be aware of. Sven [1] Sadly, not everything is logged in the changes file: creation of new classes, method deletions are not recorded. -- Sven Van Caekenberghe http://stfx.eu Smalltalk is the Red Pill

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stream usage in workspace
by Ben Coman Nov. 5, 2012

Nov. 5, 2012

I am refereshing my familiarity with streams by looking at PharoByExample1 which says... "You have to remember that each time you open a stream on a ï¬le, you have to close it too." Does that mean if in Workspace I iteratively develop some code to process a stream, so that I am continually running... myStream := FileStream readOnlyFileNamed: 'C:\test.txt. ...so that 'myStream' is overwritten each time such that I lose reference to the previous stream, and I am no longer able to send #close to it, am I creating a memory leak in my image ? My prior assumption has been that once 'myStream' drops the reference drops to the previous stream, garbage collection would take care of 'everything'. cheers -ben

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secure sockets https in Zinc
by Cameron Sanders Nov. 3, 2012

Nov. 3, 2012

In the method... ZnNetworkingUtils >> streamClassForScheme: scheme scheme = #http ifTrue: [ ^ self socketStreamClass ]. scheme = #https ifTrue: [ ^ self secureSocketStreamClass ifNil: [ self error: 'No secure socket stream class set or available' ] ]. (ZnUnknownScheme scheme: scheme) signal I am getting the error indicating the lack fo secureSocketStreamClass. The initialize and lazy-initialization try to use ZdcSecureSocketStream, but that is not found. I am using Pharo 1.4 (downloaded & configured last summer) with Pier3 loaded, along with Zinc-HTTP (SvenVanCaekenberghe.280), Zinc-Path-HTTPSocket (StephaneDucasse.2) and Zinc-Seaside (SvenVanCaekenberghe.22). I see numerous updates to those and various other new packages. I believe what I have was pulled in by the following last summer: Gofer new squeaksource: 'MetacelloRepository'; package: 'ConfigurationOfPier3'; load. (Smalltalk at: #ConfigurationOfPier3) load. Gofer it squeaksource: 'MetacelloRepository'; package: 'ConfigurationOfPier3AddOns'; load. (Smalltalk at: #ConfigurationOfPier3AddOns) load. - What is the recommended update approach for me, by those *in the know*? Thanks in advance, Cam

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Gettext in Pharo 1.4
by Chris Nov. 3, 2012

Nov. 3, 2012

Hi All, Is anyone maintaining the above package? I had a few issues when trying to use it in Pharo 1.4 Summer but have done a few fixes and it is now working well for me; would like to run them by someone who knows a bit more about it first. Thanks Chris

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Acquiring lock, releasing in callback
by Sebastian Nozzi Nov. 2, 2012

Nov. 2, 2012

Hello Dear Pharo users, threads and co. are giving me headaches :-) I wanted to ask for advice... What do I use in Pharo to prevent more than one thread entering a region, but "releasing" the exclusivity in another block/callback? For example, let's suppose there is an hypothetical class "Lock" that does that. lock acquire. longOperation performWhenFinished: [ callback code ... lock release ]. ... rest of the program ... Is there something like that? Or do I have to simulate it with something else? (Semaphore?) I am aware or Monitor/Mutex critical:, but I am not sure I can use it in my case. Thanks in advance, Sebastian

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