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  • Outputing value of TrueClass / FalseClass to integer or string/

    - by Nick Gorbikoff
    Hello. I'm trying to figure out if there is an easy way to do the following short of adding to_i method to TrueClass/FalseClass. Here is a dilemma: I have a boolean field in my rails app - that is obviously stored as Tinyint in mysql. However - I need to generate xml based of the data in mysql and send it to customer - there SOAP service requires the field in question to have 0 or 1 as the value of this field. So at the time of the xml generation I need to convert my False to 0 and my True to 1 ( which is how they are stored in the DB). Since True & False lack to_i method I could write some if statement that generate either 1 or 0 depending on true/false state. However I have about 10 of these indicators and creating and if/else for each is not very DRY. So what you recommend I do? Or I could add a to_i method to the True / False class. But I'm not sure where should I scope it in my rails app? Just inside this particular model or somewhere else?

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  • WiX: Forcefully launch uninstall previous using CustomAction

    - by leiflundgren
    I'm writing a new major upgrade of our product. In my installer I start by finding configuration settings of the previous version, then I'd like to uninstall the previous version. I have found several guides telling me how one should make a MSI suitable for such upgrades. However, the previous was not an MSI. It was not according to best practices. It does, however, in registry HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall{GUID} specify an UninstallString. Using a RegistrySearch I can easy find the command below, which I store in UNINSTALL_CMD. RunDll32 C:\PROGRA~1\COMMON~1\INSTAL~1\PROFES~1\RunTime\10\01\Intel32\Ctor.dll,LaunchSetup "C:\Program Files\InstallShield Installation Information\{GUID}\setup.exe" -l0x9 -removeonly 4: I cannot get the hang of the CustomAction needed to perform the actual uninstall. <CustomAction Id="ca.UninstPrev" Property="UNINSTALL_CMD" ExeCommand="" /> The MSI logs says: Info 1721. There is a problem with this Windows Installer package. A program required for this install to complete could not be run. Contact your support personnel or package vendor. Action: ca.UninstallPrevious, location: RunDll32 C:\PROGRA~1\COMMON~1\INSTAL~1\PROFES~1\RunTime\10\01\Intel32\Ctor.dll,LaunchSetup "C:\Program Files\InstallShield Installation Information{GUID}\setup.exe" -l0x9 -removeonly, command: Anyone seeing what I am doing wrong here? Regards Leif

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  • MySQL-python 1.2.3 and OS X 10.5: 64- or 32-bit?

    - by Dave Everitt
    I've been happily using Django and MySQL in development on an existing machine running OS X 10.4 Tiger, and have set up a similar environment in 10.5 Leopard on a new 64-bit MacBook, with a working MySQL and Python 2.6.4. However, now I want them to communicate, easy_install MySQL-python gave ld warnings that the file is not of the required architecture, which led me to test my Python 2.4.6 install (from the Mac OS X disc image): >>> import sys >>> sys.maxint 2147483647 Ah. So my Python install appears to be 32-bit and (I think?) won't install MySQL-python for my 64-bit MySQL. There are lots of hacks out there for MySQL-python on OS X (mostly 1.2.2), but - after hours of reading - I'm pretty sure they won't fix this architecture mismatch. So I'm stuck because I can't decide whether to: give up, remove the 64-bit MySQL install (thorough methods, please?) and use the 32-bit MySQL disc image instead; re-install Python in 64-bit mode from the tarball, --with-universal archs-64-bit and --enable-universalsdk= as detailed in Python.org's 2.6 news. So my questions for anyone who has encountered this issue are: Is installing 64-bit Python on OS X 10.5 worth bothering with? If so, (naive, lazy question!) how are the two required arguments combined? If I just skip along in 32-bit (as on my working setup) what am I missing? I'm after a hassle-free install that's easy to reproduce on other machines (possible student use) so I'd really welcome your opinions, please!

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  • Getting jQuery to return an ajax object

    - by japancheese
    Hello, The question title is a bit strange because I'm not exactly sure how to phrase the problem. The issue is that I have many links to which I want to bind a click event with an ajax call, and I'm just looking to refactor some duplicate code into a single area. The links I'm trying to bind an ajax call only have one thing that differentiates them, and that's an id from a previously declared object. So I have lots of code that looks like this: $("a.link").bind('click', function() { id = obj.id; $.ajax({ url: "/set/" + id, dataType: 'json', type: "POST" }) }); I was trying to refactor it into something like this: $("a.link").bind('click', ajax_link(obj.id)); function ajax_link(id) { $.ajax({ url: "/set/" + id, dataType: 'json', type: "POST" }) }); However, as you can imagine, this just actually makes the ajax call when the element is binded with the click event. Is there an easy way to refactor this code so I can extract out the common ajax code into its own function, and hopefully reduce the number of lines of jQuery in my current script?

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  • Is there any way to combine transparency and "ajax usability" with HTML templates

    - by Sam
    I'm using HTML_Template_Flexy in PHP but the question should apply to any language or template library. I am outputting a list of relatively complex objects. In the beginning I just iterated over a list of the objects and called a toHtml method on them. When I was about to have my layout designer look over the template I noticed that it was too opaque and that he would have ended up looking through and/or editing many additional php source files to see what really gets generated by the toHtml method. So I extracted most of the HTML strings in the php classes up to the template which made for one clear file where you can see the whole page structure at once. However this causes problems when you want to add an object to the list using javascript. Then I have to keep the old toHtml method and maintain both the main template and the html strings at the same time, so I can output just the HTML for a new object that should be added to the page. So I'm back to the idea of using smaller templates for the objects that make up the page, but I was wondering if there was some easy way of having my cake and eating it too by having one template that shows the whole page but also the mini-templates for smaller objects on the page. Edit: Yes, updating the page is not a problem at all. My concern is with having both maintainability and transparency of the template files. If I have one single template for the whole page, then I must maintain mini-templates of the objects that are shown on the page. If I just have the mini-templates and include them from the higher-level template it becomes more difficult to look at the top-level html and imagine what the end result will look like.

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  • Which language should I pick up: VB.Net or C#

    - by magius
    I'm looking to pick up either C# or VB.Net. I'd done a fair bit of VB6 programming in the past. I'm looking at getting the book, Visual Basic .NET or C#, Which to Choose? but I'm hoping that someone has read it, or used both languages and can offer advice. Should I just RTFB? Edit: Anders Sandvig raised a valid question. I'm intending to develop ActiveX applications that will be served through IE. Edit: Given that the functionality is pretty close and my favored approach to learning is to "just build it" and solve problems by looking it up on the internet, I've decided that the choice of language will be based on how easy it is to learn it. I looked around and found sites like C# Corner that supports my approach. Personal note: I wish I could also select Seb Nilsson's response as an accepted answer as well. Thanks guys for your input! Alright, then! I admit, theoretically, this topic is subjective; but a quick tally of answers seems to skew votes heavily in C#'s favor. Anyway, I'm really after experiences like what Keith's alluding to. I'm hoping he'll return to this topic and drop us a few more gems.

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  • Hi, How can I convert a dynamic web page to pdf?

    - by Jemma Diampuan
    I have a dynamic webpage that I created using html and php... I already have sample codes that can convert a static web page to pdf... But my problem is my web page is dynamic... So is there a way to convert my page to pdf? If yes, please provide some easy to understand codes... thank... Anyway, here is my code: //session variable $userID = 1; $receipt = &new Receipt(); $receipt->queryReceiptInfo($userID); $receiptID = $receipt->getReceiptID(); $receiptIssueDate = $receipt->getReceiptIssueDate(); $customer = $receipt->getCustomer(); $salesID = $receipt->getSalesID(); $salesDetail = &new SalesDetail($salesID); $salesDetails = $salesDetail->viewSalesDetail(); //session variable $businessID = 1; $business = &new Business('', $businessID); $business->queryBusinessName(); $businessName = $business->getBusinessName(); $rows = sizeof($salesDetails); $columns = sizeof($salesDetails[0]); ? Receipt No. Date Issued Business Customer Item Quantity Sub-Total "; for($j = 0; $j ".$salesDetails[$i][$j].""; } $totalPrice += (double)$salesDetails[$i][2]; echo ""; } ? Total Price

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  • Where to put data management rules for complex data validation in ASP.NET MVC?

    - by TheRHCP
    Hello, I am currently working on an ASP.NET MVC2 project. This is the first time I am working on a real MVC web application. The ASP.NET MVC website really helped me to get started really fast, but I still have some obscure knowledge concerning datamodel validation. My problem is that I do not really know where to manage my filled datamodel when it comes to complex validation rules. For example, validating a string field with a Regex is quite easy and I know that I just have to decorate my field with a specific attribute, so data management rules are implemented in the model. But if I have multiple fields that I need to validate which each other, for example multiple datetime that need to be correctly set following a specific time rule, where do I need to validate them? I know that I could create my own validation attributes, but sometimes validation ask a specific validation path which is to complex to be validated using attributes. This first question also leads me to a related question which is, is it right to validate a model in the controller? Because for the moment that is the only way I found for complex validation. But I find this a bit dirty and I feel it does not really fit a the controller role and much harder to test (multiple code path). Thanks.

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  • How do I add programmatically-generated new files to source control?

    - by Alex Basson
    This is something I've never really understood about source control, specifically Subversion (the only source control I've ever used, which isn't saying much). I'm considering moving to git or Mercurial, so if that affects the answer to my question, please indicate as such. Ok. As I understand it, every time I create a new file, I have to tell SVN about it, so that it knows to add it to the repository and place it under control. Something like: svn add newfile That's fine if I'm the one creating the file: I know I created it, I know its name, I know where it lives, so it's easy to tell SVN about it. But now suppose I'm using a framework of some kind, like Rails, Django, Symfony, etc., and suppose I've already done the initial commit. All of these frameworks create new files programmatically, often many at once, in different directories, etc. etc. How do I tell the source control about these new files? Do I have to hunt each one of them down individually and add them? Is there an easier way? (Or am I possibly misunderstanding something fundamental about source control?)

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  • Where are the real risks in network security?

    - by Barry Brown
    Anytime a username/password authentication is used, the common wisdom is to protect the transport of that data using encryption (SSL, HTTPS, etc). But that leaves the end points potentially vulnerable. Realistically, which is at greater risk of intrusion? Transport layer: Compromised via wireless packet sniffing, malicious wiretapping, etc. Transport devices: Risks include ISPs and Internet backbone operators sniffing data. End-user device: Vulnerable to spyware, key loggers, shoulder surfing, and so forth. Remote server: Many uncontrollable vulnerabilities including malicious operators, break-ins resulting in stolen data, physically heisting servers, backups kept in insecure places, and much more. My gut reaction is that although the transport layer is relatively easy to protect via SSL, the risks in the other areas are much, much greater, especially at the end points. For example, at home my computer connects directly to my router; from there it goes straight to my ISPs routers and onto the Internet. I would estimate the risks at the transport level (both software and hardware) at low to non-existant. But what security does the server I'm connected to have? Have they been hacked into? Is the operator collecting usernames and passwords, knowing that most people use the same information at other websites? Likewise, has my computer been compromised by malware? Those seem like much greater risks. What do you think?

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  • virtualenv macosX --no-site-package ignored

    - by Tristram Gräbener
    Hello, I'm having problems with macOSX and virtualenv. It seems to ignore --no-site-package. Using exactly the same commands with linux (archlinux) it works. It it macOSX 10.5 with python 2.5 curl -o virtualenv.py 'http://bitbucket.org/ianb/virtualenv/raw/tip/virtualenv.py Create a new environment python virtualenv.py --no-site-packages foo New python executable in foo/bin/python Installing setuptools...........................done. Activate it source foo/bin/activate Try to install something in it. Despite virtualenv it looks for the system-wide install easy_install cherrypy Searching for cherrypy Best match: CherryPy 3.1.2 Adding CherryPy 3.1.2 to easy-install.pth file Using /Library/Python/2.5/site-packages Processing dependencies for cherrypy Finished processing dependencies for cherrypy Yet it doesn't find the module (foo)guidage-multimodal:~ tristram$ python Python 2.5.1 (r251:54863, Feb 6 2009, 19:02:12) [GCC 4.0.1 (Apple Inc. build 5465)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import cherrypy Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named cherrypy I tried PIP after looking at http://stackoverflow.com/questions/1382925/virtualenv-no-site-packages-and-pip-still-finding-global-packages However it fails installing psycopg2 (some problems with gcc). Also I would like to be able to have a setup.py (from distribute) that does the whole woork

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  • I didn't say anything treasonous, quit putting words in my mouth

    - by You guys Lie
    Where at all did I say ANYTHING about organizing some kind of anti-government activity? Nowhere. I do not give a flying fuck about America in case you hadn't realized, I'm talking about what I'm going to do when Jesus Christ returns. Besides, why would I make it easy for them to throw me in a black site prison? Use common sense, sheeple. In the end I guess it doesn't matter anyways, since I do not recognize the government as my ultimate authority. Police/Army/Whatever-- funny outfits and a shiny badge don't make you better than me. Allah will do away with your kind. However, as long as they're with me (as they semi-currently are), we have no problems. I fear the government will have other plans to control the population when things start to further decline, and that is when they will run into problems with me and mine, and probably a large percentage of the public. You'd have to be a fucking fool to think we'd fall into anarchy immediately, given the vast resources and blind loyalty of this country. Saying there are practical limits to free speech for anything I have said in this thread is not only ignorant, it is unpatriotic. I should be being celebrated as the modern day Paul Revere for warning you people about our impending doom. You would do well to study the foundations of this country. Nothing I have said is treasonous at all. Besides, the DoD knows I'm harmless until shit pops off, they have bigger fish to fry right now, go forward. Keep in mind, I don't personally have to do anything to overthrow the government. I just said, I would not advocate for any paramilitary organizations at this time, only if/after we dissolve into (more) tyranny. I am not a terrorist, like some soldiers in Iraq. The machine is doing a great job of ruining itself, while I get to comfortably laugh at it on the nightly news knowing that I'm ready for it to shut down.

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  • Is ther any tool to extract keywords from a English Text or Article In Java?

    - by user555581
    Dear Experts, I am trying to identify the type of the web site(In English) by machine. I try to download the homepage of the web iste, download html page, parsing and get the content of the web page. Such as here are some context from CNN.com. I try to get the keywords of the web page, mapping with my database. If the keywords include like news, breaking news. The web site will go to the news web sites. If there exist some words like healthy, medical, it will be the medical web site. There exist some tools can do the text segmentation, but it is not easy to find a tool do the semantic, such as online shopping, it is a keywords, should not spilt two words. The combination will be helpful information. But "oneline", "shopping" will be less useful as it may exist online travel... • Newark, JFK airports reopen • 1 runway reopens at LaGuardia Airport • Over 4,155 flights were cancelled Monday • FULL STORY * LaGuardia Airport snowplows busy Video * Are you stranded? | Airport delays * Safety tips for winter weather * Frosty fun Video | Small dog, deep snow Latest news * Easter eggs used to smuggle cocaine * Salmonella forces cilantro, parsley recall * Obama's surprising verdict on Vick * Blue Note baritone Bernie Wilson dead * Busch aide to 911: She's not waking up * Girl, 15, last seen working at store in '90 * Teena Marie's death shocks fans * Terror network 'dismantled' in Morocco * Saudis: 'Militant' had al Qaeda ties * Ticker: Gov. blasts Obama 'birthers' * Game show goof is 800K mistakeVideo * Chopper saves calf on frozen pondVideo * Pickpocketing becomes hands-freeVideo * Chilean miners going to Disney World * Who's the most intriguing of 2010? * Natalie Portman is pregnant, engaged * 'Convert all gifts from aunt' CNNMoney * Who controls the thermostat at home? * This Just In: CNN's news blog

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  • How to refactor this database to allow sync. with smart clients?

    - by Anton Zvgny
    Howdy, I have inherited the following database: http://i46.tinypic.com/einvjr.png (EDIT: I cannot post images, so here goes the link) This currently runs 100% online thru an Asp.Net web app , but some employees will need to have offline access to this database to either get documents or to insert new documents for later synchronization when back to the office. What changes need to be made to this database scheme to support such scenario (sync smart clients with central web database)? Thanks! ps. I'm not an developer/dba, i'm just an mechanic engineer tasked with changing this app, so, take it easy on me :D ps1. We're using MSSQL Server for the online central database and MSSQL Compact for the smart client. ps2. the ImageGuid field of the images table is used to save the images to the file system. The web app takes the guid and create folders according to the first 3 initial letters to persist the image to the file system. ps3. The users of the smart client not always get server data first and then go modifying to sync later the changes. Most of the time they start working completely offline (with a blank local database) and later sync the data to the server. ps4. All the users of the smart client app have an account at the web app.

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  • Scripting for JAVA - a problem to solve

    - by Parhs
    Hello.. I had no luck to find a good way to achieve the following: suppose i let the user to write a condition using javascript INS5 || ASTO.valueBetween(10,210) ... etc.... I tried to find a way to get the variables name...from JAVA... Rhino library didnt help a lot... However i found that handling exceptions i could get all the identifiers! Everything is great but one little problem..... How teh heck i can replace these identifiers with the numeric id of each var ? eg INS to be _234 ASTO to be _331 ? I want to to this replace because the name may change... I could do it using a replace but i know that this isnt easy because... 1) replacing _23 with MPLAH may replace also _234...(this could be fixed with regexp somehow..) 2)what if _23 is in a comment section ? rare to happen but possible /* _23 fdsafd ktl */ it should be replaced... 3)what if is a name of a function ??? _32() {} rare but shouldnt be replaced 4) what if it is enclosed in "" or ''??? And i am sure that there should me a lot more cases..... any ideas ? thank yoyu for your time

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  • C#/Java: Proper Implementation of CompareTo when Equals tests reference identity

    - by Paul A Jungwirth
    I believe this question applies equally well to C# as to Java, because both require that {c,C}ompareTo be consistent with {e,E}quals: Suppose I want my equals() method to be the same as a reference check, i.e.: public bool equals(Object o) { return this == o; } In that case, how do I implement compareTo(Object o) (or its generic equivalent)? Part of it is easy, but I'm not sure about the other part: public int compareTo(Object o) { if (! (o instanceof MyClass)) return false; MyClass other = (MyClass)o; if (this == other) { return 0; } else { int c = foo.CompareTo(other.foo) if (c == 0) { // what here? } else { return c; } } } I can't just blindly return 1 or -1, because the solution should adhere to the normal requirements of compareTo. I can check all the instance fields, but if they are all equal, I'd still like compareTo to return a value other than 0. It should be true that a.compareTo(b) == -(b.compareTo(a)), and the ordering should stay consistent as long as the objects' state doesn't change. I don't care about ordering across invocations of the virtual machine, however. This makes me think that I could use something like memory address, if I could get at it. Then again, maybe that won't work, because the Garbage Collector could decide to move my objects around. hashCode is another idea, but I'd like something that will be always unique, not just mostly unique. Any ideas?

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  • iPhone and Core Data: how to retain user-entered data between updates?

    - by Shaggy Frog
    Consider an iPhone application that is a catalogue of animals. The application should allow the user to add custom information for each animal -- let's say a rating (on a scale of 1 to 5), as well as some notes they can enter in about the animal. However, the user won't be able to modify the animal data itself. Assume that when the application gets updated, it should be easy for the (static) catalogue part to change, but we'd like the (dynamic) custom user information part to be retained between updates, so the user doesn't lose any of their custom information. We'd probably want to use Core Data to build this app. Let's also say that we have a previous process already in place to read in animal data to pre-populate the backing (SQLite) store that Core Data uses. We can embed this database file into the application bundle itself, since it doesn't get modified. When a user downloads an update to the application, the new version will include the latest (static) animal catalogue database, so we don't ever have to worry about it being out of date. But, now the tricky part: how do we store the (dynamic) user custom data in a sound manner? My first thought is that the (dynamic) database should be stored in the Documents directory for the app, so application updates don't clobber the existing data. Am I correct? My second thought is that since the (dynamic) user custom data database is not in the same store as the (static) animal catalogue, we can't naively make a relationship between the Rating and the Notes entities (in one database) and the Animal entity (in the other database). In this case, I would imagine one solution would be to have an "animalName" string property in the Rating/Notes entity, and match it up at runtime. Is this the best way to do it, or is there a way to "sync" two different databases in Core Data?

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  • How to wrap a thirdparty library COM class for notifications in a C++ project

    - by geocoin
    A thirdparty vendor has provided a COM interface as an external API to their product, and for sending instructions to it, it's fine with the mechanism of generating class wrappers with visual studio by importing from the dll, then creating instances of the created classes, calling their CreateDispatch(), using the access functions and releasing when done. For return notifications, I'd normally create an EventsListener class derived from IDispatch using the Invoke function to handle events returning from the interface. This vendor has created an Events lass which I have to wrap and expose, then explicitly tell the installation where to look. all the example are given is C# where it's really easy, but I'm struggling on how to do it in C++ in the C# example, the interop dll provided is simply added as a reference and derived into a class like so: using System; using System.Runtime.InteropServices; using System.Windows.Forms; using System.Text; using <THIER INTEROP LIB> namespace some.example.namespace { [ComVisible(true)] public class EventViewer : IEvents //where IEvents is their events class { public void OnEvent(EventID EventID, object pData) //overridden function { //event handled here } } } In broad terms I assume that I must create a COM interface, since they require a ProgID from me to instantiate, but how do I derive that's been wrapped by the import and then expose the created class to COM I'm just not sure where to even start, as all the tutorials I've seen so far talk in terms of creating brand new classes not wrapping a third party one

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  • how to push different local git branches to heroku/master

    - by lsiden
    Heroku has a policy of ignoring all branches but 'master'. While I'm sure Heroku's designers have excellent reasons for for this policy (I'm guessing for storage and performance optimization), the consequence to me as a developer is that whatever local topic branch I may be working on, I would like an easy way to switch Heroku's master to that local topic branch and do a "git push heroku -f" to over-write master on Heroku. What I got from reading the "Pushing Refspecs" section of http://progit.org/book/ch9-5.html is git push -f heroku local-topic-branch:refs/heads/master What I'd really like is a way to set this up in the config file so that "git push heroku" always does the above, replacing local-topic-branch with the name of whatever my current branch happens to be. If anyone knows how to accomplish that, please let me know! The caveat for this, of course, is that this is only sensible if I am the only one who can push to that Heroku app/repository. A test or QA team might manage such a repository to try out different candidate branches, but they would have to coordinate so that they all agree on what branch they are pushing to it on any given day. Needless to say, it would also be a very good idea to have a separate remote repository (like Github) without this restriction for backing everything up to. I'd call that one "origin" and use "heroku" for Heroku so that "git push" always backs up everything to origin, and "git push heroku" pushes whatever branch I'm currently on to Heroku's master branch, overwriting it if necessary. Can anybody tell me if this would work? [remote "heroku"] url = [email protected]:my-app.git push = +refs/heads/*:refs/heads/master I'd like to hear from someone more experienced before I begin to experiment, although I suppose I could create a dummy app on Heroku and experiment with that. As for fetching, I don't really care if the Heroku repository is write-only. I still have a separate repository, like Github, for backup and cloning of all my work. Footnote: This question is similar to, but not quite the same as http://stackoverflow.com/questions/1489393/good-git-deployment-using-branches-strategy-with-heroku

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  • Which languages support *recursive* function literals / anonymous functions?

    - by Hugh Allen
    It seems quite a few mainstream languages support function literals these days. They are also called anonymous functions, but I don't care if they have a name. The important thing is that a function literal is an expression which yields a function which hasn't already been defined elsewhere, so for example in C, &printf doesn't count. EDIT to add: if you have a genuine function literal expression <exp>, you should be able to pass it to a function f(<exp>) or immediately apply it to an argument, ie. <exp>(5). I'm curious which languages let you write function literals which are recursive. Wikipedia's "anonymous recursion" article doesn't give any programming examples. Let's use the recursive factorial function as the example. Here are the ones I know: JavaScript / ECMAScript can do it with callee: function(n){if (n<2) {return 1;} else {return n * arguments.callee(n-1);}} it's easy in languages with letrec, eg Haskell (which calls it let): let fac x = if x<2 then 1 else fac (x-1) * x in fac and there are equivalents in Lisp and Scheme. Note that the binding of fac is local to the expression, so the whole expression is in fact an anonymous function. Are there any others?

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  • Testing fault tolerant code

    - by Robert
    I’m currently working on a server application were we have agreed to try and maintain a certain level of service. The level of service we want to guaranty is: if a request is accepted by the server and the server sends on an acknowledgement to the client we want to guaranty that the request will happen, even if the server crashes. As requests can be long running and the acknowledgement time needs be short we implement this by persisting the request, then sending an acknowledgement to the client, then carrying out the various actions to fulfill the request. As actions are carried out they too are persisted, so the server knows the state of a request on start up, and there’s also various reconciliation mechanisms with external systems to check the accuracy of our logs. This all seems to work fairly well, but we have difficult saying this with any conviction as we find it very difficult to test our fault tolerant code. So far we’ve come up with two strategies but neither is entirely satisfactory: Have an external process watch the server code and then try and kill it off at what the external process thinks is an appropriate point in the test Add code the application that will cause it to crash a certain know critical points My problem with the first strategy is the external process cannot know the exact state of the application, so we cannot be sure we’re hitting the most problematic points in the code. My problem with the second strategy, although it gives more control over were the fault takes, is I do not like have code to inject faults within my application, even with optional compilation etc. I fear it would be too easy to over look a fault injection point and have it slip into a production environment.

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  • Capturing Set Behavior with Mutating Elements

    - by Carl
    Using the Guava library, I have the following situation: SetMultimap<ImmutableFoo, Set<Foo>> setMM = HashMultimap.create(); Set<Foo> mask = Sets.newHashSet(); // ... some iteration construct { setMM.put(ImmutableFoo1, Sets.difference(SomeSetFoo1,mask)); setMM.put(ImmutableFoo1, Sets.difference(SomeSetFoo2,mask)); mask.add(someFoo); } that is, the same iteration to create the setMM is also used to create the mask - this can of course result in changes to hashCode()s and create duplicates within the SetMultimap backing. Ideally, I'd like the duplicates to drop without me having to make it happen, and avoid repeating the iteration to separately construct the multimap and mask. Any easy libraries/Set implementations to make that happen? Alternatively, can you identify a better way to drop the duplicates than: for (ImmutableFoo f : setMM.keySet()) setMM.putAll(f,setMM.removeAll(f)); revisiting the elements is probably not a performance problem, since I could combine a separate filter operation that needs to visit all the elements anyway.

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  • Python Django Global Variables

    - by Joe J
    Hi all, I'm looking for simple but recommended way in Django to store a variable in memory only. When Apache restarts or the Django development server restarts, the variable is reset back to 0. More specifically, I want to count how many times a particular action takes place on each model instance (database record), but for performance reasons, I don't want to store these counts in the database. I don't care if the counts disappear after a server restart. But as long as the server is up, I want these counts to be consistent between the Django shell and the web interface, and I want to be able to return how many times the action has taken place on each model instance. I don't want the variables to be associated with a user or session because I might want to return these counts without being logged in (and I want the counts to be consistent no matter what user is logged in). Am I describing a global variable? If so, how do I use one in Django? I've noticed the files like the urls.py, settings.py and models.py seems to be parsed only once per server startup (by contrast to the views.py which seems to be parsed eache time a request is made). Does this mean I should declare my variables in one of those files? Or should I store it in a model attribute somehow (as long as it sticks around for as long as the server is running)? This is probably an easy question, but I'm just not sure how it's done in Django. Any comments or advice is much appreciated. Thanks, Joe

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  • Making one table equal to another without a delete *

    - by Joshua Atkins
    Hey, I know this is bit of a strange one but if anyone had any help that would be greatly appreciated. The scenario is that we have a production database at a remote site and a developer database in our local office. Developers make changes directly to the developer db and as part of the deployment process a C# application runs and produces a series of .sql scripts that we can execute on the remote side (essentially delete *, insert) but we are looking for something a bit more elaborate as the downtime from the delete * is unacceptable. This is all reference data that controls menu items, functionality etc of a major website. I have a sproc that essentially returns a diff of two tables. My thinking is that I can insert all the expected data in to a tmp table, execute the diff, and drop anything from the destination table that is not in the source and then upsert everything else. The question is that is there an easy way to do this without using a cursor? To illustrate the sproc returns a recordset structured like this: TableName Col1 Col2 Col3 Dest Src Anything in the recordset with TableName = Dest should be deleted (as it does not exist in src) and anything in Src should be upserted in to dest. I cannot think of a way to do this purely set based but my DB-fu is weak. Any help would be appreciated. Apologies if the explanation is sketchy; let me know if you need anymore details.

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  • Form Validation using Javascript inside PHP

    - by Mikey1980
    I have a simple problem but no matter what I try I can't see to get it to work. I have a form on a php page and I need to validate the qty value on my form so that it doesn't exceed $qty (value pulled from mySQL) and is not less than zero. Sounds easy--hmm wish it were..lol! I had it checking if the value was numeric and in my attempts to make this work I even broke that--not a good morning..lol! Here's a snip of my Java Fn: <script type='text/javascript'> function checkQty(elem){ var numericExpression = /^[0-9]+$/; if(elem.value.match(numericExpression)){ return true; }else{ alert("Quantity for RMA must be greater than zero and less than original order!"); elem.focus(); return false; } } </script> The function is called from the submit button, onClick: <input type="submit" name="submit" onclick="checkQty(document.getElementById('qty')";"> I've tried: var numericExpression = /^[0-9]+$/; if(elem.value.match(numericExpression) || elem.value < 0 || elem.value > <? int($qty) ?>){ No dice....HELP!?!

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