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  • overriding callbacks avoiding attribute pollution

    - by pygabriel
    I've a class that has some callbacks and its own interface, something like: class Service: def __init__(self): connect("service_resolved", self.service_resolved) def service_resolved(self, a,b c): ''' This function is called when it's triggered service resolved signal and has a lot of parameters''' the connect function is for example the gtkwidget.connect, but I want that this connection is something more general, so I've decided to use a "twisted like" approach: class MyService(Service): def my_on_service_resolved(self, little_param): ''' it's a decorated version of srvice_resolved ''' def service_resolved(self,a,b,c): super(MyService,self).service_resolved(a,b,c) little_param = "something that's obtained from a,b,c" self.my_on_service_resolved(little_param) So I can use MyService by overriding my_on_service_resolved. The problem is the "attributes" pollution. In the real implementation, Service has some attributes that can accidentally be overriden in MyService and those who subclass MyService. How can I avoid attribute pollution? What I've thought is a "wrapper" like approach but I don't know if it's a good solution: class WrapperService(): def __init__(self): self._service = service_resolved # how to override self._service.service_resolved callback? def my_on_service_resolved(self,param): ''' '''

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  • How to handle added input data colums without having to maintain multiple versions of SSIS packages?

    - by GLFelger
    I’m writing to solicit ideas for a solution to an upcoming problem. The product that provides data to our ETL process currently has multiple versions. Our clients are all using some version of the product, but not all use the same version and they will not all be upgraded at the same time. As new versions of the product are rolled out, the most common change is to add new data columns. Columns being dropped or renamed may happen occasionally, but our main focus right now is how to handle new columns being added. The problem that we want to address is how to handle the data for clients who use an older version of the product. If we don’t account for the new columns in our SSIS packages, then the data in those columns for clients using an older product version will not be processed. What we want to avoid is having to maintain a separate version of the SSIS packages for each version of the product. Has anyone successfully implemented a solution for this situation?

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  • Domain Redirection While Maintaining Original URL

    - by Steve
    I have two domains ("this_site.com" and "that_site.com") that I want to point to the same place (same set of files). BUT What I really want to do is maintain the original URL in the address bar while the visitor accesses the different pages. Example: The primary domain holding the web files is "this_site.com". If I type in "that_site.com" in the address bar, I want the address bar to keep displaying "that_site.com" no matter where they go on the web site. Normal domain redirection causes the URL displayed in the address bar to change to the 'master' domain (i.e. the visitor that typed in "that_site.com" will see the address bar's URL change to "this_site.com"). Is there some sort of .htaccess trick that I can employ to do this? What I'm trying to do is NOT confuse visitors who visit one URL and find themselves on a different URL as well as avoid the additional expense and trouble of having to maintain two separate hosting accounts.

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  • How can I double-enhance a class with cglib?

    - by artemb
    Hi there! Here's the code: Patient patient = factory.createPatient(); Enhancer enhancer = new Enhancer(); enhancer.setSuperclass(patient.getClass()); enhancer.setCallback(new DefaultMethodInterceptor(patient)); patient = (Patient) enhancer.create(); assertThat(patient.getFirstName()).isNotNull(); Enhancer enhancer2 = new Enhancer(); enhancer2.setSuperclass(patient.getClass()); enhancer2.setCallback(new DefaultMethodInterceptor(patient)); patient = (Patient) enhancer2.create(); assertThat(patient.getFirstName()).isNotNull(); It fails on the last assert with net.sf.cglib.core.CodeGenerationException: java.lang.reflect.InvocationTargetException-->null ... Caused by: java.lang.reflect.InvocationTargetException ... Caused by: java.lang.ClassFormatError: Duplicate method name&signature in class file my/package/entity/Patient$$EnhancerByCGLIB$$ca1e6685$$EnhancerByCGLIB$$f52743be I ask this because I want to enhance Hibernate's entities, but sometimes it returns already enhanced ones by itself and my second enhancement fails. How can I avoid this?

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  • Downloading game assests to SD card on Android

    - by hgpc
    I'm developing an Android game that has to download some assets to the SD card to keep the size of the app as small as possible. I was thinking of using an uncompressed zip file to bundle all the assets. A requirement from the client is to protect these assets as much as possible. Being part of the apk is considered enough protection, but if I do this the apk size will be enormous. If I just put a zip bundle in the SD card, then anyone can unzip it and explore its contents. Is there a simple way to do this without retorting to horrid DRM? Obviously if someone really wants to check the resources of an Android game, they can. I'm just looking for a simple solution to avoid making this very easy.

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  • MySQL: Query to obtain recipes using all given ingredients.

    - by John_A
    hi I have the following simplified tables: CREATE TABLE recipe(id int, name varchar(25)); CREATE TABLE ingredient(name varchar(25)); CREATE TABLE uses_ingredient(recipe_id int, name varchar(25)); I want to make a query that returns all id's of recipes that contain both Chicken and Cream. I have tried SELECT recipe_id FROM uses_ingredient INNER JOIN (SELECT * FROM ingredient WHERE name="Chicken" OR name="Cream") USING (name) GROUP BY recipe_id HAVING COUNT(recipe_id) >= (SELECT COUNT(*) FROM theme); which gives me :"ERROR 1248 (42000): Every derived table must have its own alias" and is probably wrong too. Next I tried SELECT recipe_id FROM (SELECT * FROM ingredient WHERE name="Chicken" OR name="Cream") AS t INNER JOIN uses_ingredient USING (name) GROUP BY recipe_id HAVING COUNT(recipe_id)>= (SELECT COUNT(*) FROM t); which gives "ERROR 1146 (42S02): Table 'recipedb.t' doesn't exist" I want to avoid creating temporary tables including using ENGINE=MEMORY.

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  • UITableViewController executes delate functions before network request finishes

    - by user1543132
    I'm having trouble trying to populate a UITableView with the results of a network request. It seems that my code is alright as it works perfectly when my network is speedy, however, when it's not, the function - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath- still executes, which results in a bad access error. I presume that this is because the array that the aforesaid function attempts to utilize has not been populated. This brings me to my question: Is there anyway that I can have the UITableView delegate methods delayed to avoid this? - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"AlbumsCell"; //UITableViewCell *basicCell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath]; AlbumsCell *cell = (AlbumsCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (!cell) { **// Here is where the Thread 1: EXC_BAD_ACCESS (code=2 address=0x8)** cell = [[[AlbumsCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } Album *album = [_albums objectAtIndex:[indexPath row]]; [cell setAlbum:album]; return cell; }

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  • How can I lock the cursor to the inside of a window on Linux?

    - by ZorbaTHut
    I'm trying to put together a game for Linux which involves a lot of fast action and flinging around of the mouse cursor. If the user wants to play in windowed mode, I'd quite like to lock the cursor to the inside of the window to avoid accidentally changing programs in the heat of battle (obviously this will cancel itself if the user changes programs or hits escape for the pause menu.) On Windows, this can be accomplished easily with ClipCursor(). I can't find an equivalent on Linux. Is there one? I plan to do this in pure X code, but obviously if anyone knows of a way to do this in any Linux windowing library then I can just read the source code and figure out how to duplicate it in X.

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  • Can I reproduce Scala's behavior for == ?

    - by JPP
    In Programming in Scala, I can read that the == operator behaves as if it was defined like this: final def == (that: Any): Boolean = if (null eq this) {null eq that} else {this equals that} But there must actually be compiler magic to avoid null pointer exceptions, right? Is there any way for me to replicate this behavior with pure Scala; i.e., have an operator/method return one thing if the receiver is null and another one if it isn't? What I mean is an actual implementation of null eq this. I suppose I can write a "pimp" and then define the method on the wrapper class, but is there a more direct way to do this?

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  • How to organize Windows Phone code base to target both 7.x and 8 platforms

    - by ljubomir
    I took over a Windows Phone project which was previously targeting WP 7.1 platform, and with the recent announcement of the new platform it should target WP 8 as well. My VS 2010 solution consists on several projects (Data access, Model, Tests and WP7 client app) and i am wandering on how to include support for WP8. I have to note that the code-base is not compatible with WP8, due to usage of Toolkit controls and other 3rd party libraries targeted for WP7.1 specifically. Also there is another problem with the Visual Studio versions - WP7.1 can work with VS 2010, but WP8 requires VS 2012. Should i move the whole code-base to VS 2012? Any good advice on how to organize code-base in a most meaningful way in order to avoid duplication and possible painful maintenance? I am thinking between one solution - multiple projects vs. multiple solutions - reusable projects approach. Code duplication (like two separate folders/solutions) should be the least possible approach (fallback).

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  • Sharing base object with inheritance

    - by max
    I have class Base. I'd like to extend its functionality in a class Derived. I was planning to write: class Derived(Base): def __init__(self, base_arg1, base_arg2, derived_arg1, derived_arg2): super().__init__(base_arg1, base_arg2) # ... def derived_method1(self): # ... Sometimes I already have a Base instance, and I want to create a Derived instance based on it, i.e., a Derived instance that shares the Base object (doesn't re-create it from scratch). I thought I could write a static method to do that: b = Base(arg1, arg2) # very large object, expensive to create or copy d = Derived.from_base(b, derived_arg1, derived_arg2) # reuses existing b object but it seems impossible. Either I'm missing a way to make this work, or (more likely) I'm missing a very big reason why it can't be allowed to work. Can someone explain which one it is? [Of course, if I used composition rather than inheritance, this would all be easy to do. But I was hoping to avoid the delegation of all the Base methods to Derived through __getattr__.]

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  • is vim able to detect in which language a file is written, and then load the correct dictionnary ?

    - by Niels
    I am using several languages, and by now I am obliged to indicate vim with which of these the spell check must be done. Is there a way to set up vim so that he automatically detects the correct one ? I remember vaguely that in a previous version of vim, when the spell check was not integrated, this was possible, using the vimspell script. It would be even better if this could apply not only to a file but also to a portion of a file, since I frequently mix several languages in a single file. Of course, I would like to avoid to load several dictionaries simultaneously.

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  • How can you check if a file exists before including/importing it in JSP?

    - by codeninja
    Assuming that requestScope.importMe is expecting a path to a jsp file <c:choose> <c:when test="${!empty requestScope.importMe && fileExists(requestScope.importMe) }"> <c:import url="${requestScope.importMe}" /> ... How can I check if the file exists before trying to include it so that an error is not thrown? I'd like to avoid using inline Java. Something using one of the JSTL tags is the preferred approach.

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  • iPhone view architecture question

    - by Joe
    So I have (for instance) three views: A: root view B: a view functionally identical to root C: a data entry view which collects a few piece of info What I'm trying to do is reuse C to supply the data it collects to either A or B. It should supply the data to whichever of the two it is pushed onto. The data for A is similar, but functionally distinct, to what collects for B. Right now, I'm passing data from C to A or B via a singleton class. What I'm trying to avoid is having two instances of C, one to supply data to A and B (because, in actuality, the program will have 5 total views like C. Does the question make sense?

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  • Thread Suicide on Shutdown?

    - by yar
    I have a java.util.Timer running at a fixed interval. I have added a Runtime#addShutdownHook and it shuts down when the VM ends normally or abnormally. However, it keeps the VM alive when a main terminates, unless I insist by doing a System.exit in the main. Is there any way for me to check if I'm the last Thread standing, or some other way to avoid altering a main that would exit normally on finish? Note: I know a lot of people believe that java.util.Timer is deprecated (it's not), but unless your alternative helps me solve this problem...

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  • Why does code need to be reloaded in Rails 3?

    - by Venkat D.
    I am a former PHP developer learning Rails and Sinatra. In PHP, every page request loaded all of the required files. If I changed some code and refreshed the page, I could be sure that the code was fresh. In Rails 3, Controller code is fresh on every request. However, if I modify any code in the /lib folder, I need to restart the server so the changes take effect. Why does this happen? Is it something to do with the way Ruby is designed? Is Rails doing some optimizations to avoid reloading code on every request? Thanks!

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  • returning values from function or method multiple times by only calling the class once

    - by Sokhrat Sikar
    I have a members.php file that shows my websites members. I echo members name by using foreach method. A method of Members class returns an array, then I use foreach loop in the members.php file to echo the members. I am trying to aovid writing php code in my members.php file. Is there a way to avoid using foreach inside members.php file? For example, is it possible to return value from a method couple of times? (by only calling the object once). Just like how we normally call the functions? This question doesn't make sense, but I am just trying to see if there is a away around this issue?

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  • Override decimal ToString() method

    - by Jimbo
    I have a decimal datatype with a precision of (18, 8) in my database and even if its value is simply 14.765 it will still get displayed as 14.76500000 when I use Response.Write to return its value into a webpage. Is it possible to override its default ToString method to return the number in the format #,###,##0.######## so that it only displays relevant decimal places? UPDATE I'm assuming that when one outputs number on a page like <%= item.price %> (where item.price is a number) that the number's ToString method is being called? I'm trying to avoid having to change every instance where the value is displayed by defaulting the ToString() format somehow.

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  • Is it always bad idea to use inline css for used-once property?

    - by user93422
    I have a table, with 10 columns. I want to control the width of each column. Each column is unique, right now I create an external CSS style for each column: div#my-page table#members th.name-col { width: 40px; } I know there is a best practice to avoid inline style. I do approve using external CSS for anything look'n'feel related: fonts, colors, images. But is it really better to use external CSS in this case? It does not incur extra maintenance cost. It is easier to produce. Cons I can think of: If you have separate designers and development team - using inline styles will force designers to modify content-file (aspx in my case). It might use more bandwidth. Anything else I've missed?

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  • Tests that are 2-3 times bigger than the testable code

    - by HeavyWave
    Is it normal to have tests that are way bigger than the actual code being tested? For every line of code I am testing I usually have 2-3 lines in the unit test. Which ultimately leads to tons of time being spent just typing the tests in (mock, mock and mock more). Where are the time savings? Do you ever avoid tests for code that is along the lines of being trivial? Most of my methods are less than 10 lines long and testing each one of them takes a lot of time, to the point where, as you see, I start questioning writing most of the tests in the first place. I am not advocating not unit testing, I like it. Just want to see what factors people consider before writing tests. They come at a cost (in terms of time, hence money), so this cost must be evaluated somehow. How do you estimate the savings created by your unit tests, if ever?

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  • exactly what does rake db:migrate do?

    - by happythenewsad
    Does rake db:migrate only add new migrations, or does it drop all migrations/changes and build everything new? I think rake is throwing an error because it is trying to access a table attribute in migration 040 that was deleted in migration 042. somehow my DB and rake are out of synch and I want to fix them. for you experts out there - is it common for rake to get out of synch with migrations? how can I avoid this (no, I do not hand-edit my schema or rake files).

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  • How to address thread-safety of service data used for maintaining static local variables in C++?

    - by sharptooth
    Consider the following scenario. We have a C++ function with a static local variable: void function() { static int variable = obtain(); //blahblablah } the function needs to be called from multiple threads concurrently, so we add a critical section to avoid concurrent access to the static local: void functionThreadSafe() { CriticalSectionLockClass lock( criticalSection ); static int variable = obtain(); //blahblablah } but will this be enough? I mean there's some magic that makes the variable being initialized no more than once. So there's some service data maintained by the runtime that indicates whether each static local has already been initialized. Will the critical section in the above code protect that service data as well? Is any extra protection required for this scenario?

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  • Websphere/Oracle 11 - much more Heap Usage than with Oracle 10

    - by swalkner
    Hi all, while testing our application with Oracle 11 (previously, we had Oracle 10), we saw that our server uses much more heap space. It seems as it has something to do with T4CConnection; there are 500 objects of T4CConnection allocated. Someone told me, that Oracle 11 is using SoftReferences to keep the connection pool; but we don't need that. Is that correct? Could that be the problem for the increased heap space? If yes - how can we avoid connection pooling? Thanks a lot!!

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  • Should I put a try-finally block after every Object.Create?

    - by max
    I have a general question about best practice in OO Delphi. Currently, I put try-finally blocks anywhere I create an object to free that object after usage (to avoid memory leaks). E.g.: aObject := TObject.Create; try aOBject.AProcedure(); ... finally aObject.Free; end; instead of: aObject := TObject.Create; aObject.AProcedure(); .. aObject.Free; Do you think it is good practice, or too much overhead? And what about the performance?

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  • 1120: Why can't it access the variable?

    - by Oden
    I'm new at as3, maybe thats the reason why i don't understand, why the setInterval causes an error. <mx:Script> <![CDATA[ import flash.utils.setInterval; import mx.controls.Alert; [Bindable] public var MyInt:int = 500; setInterval(function():void{ ++MyInt; },1000); ]]> </mx:Script> I have a label where the value of MyInt gets visible, the bind works perfect, i've tested it several ways, and i i create a button it grows the number, but if i use the setInterval function i get an error: Access of undefined property myInt. Why? What does cause this? Please explain it, so I can avoid errors like this. Thanks

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