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• How to DRY on CRUD parts of my Rails app?

  - by kolrie

  I am writing an app which - similarly to many apps out there - is 90% regular CRUD things and 10% "juice", where we need nasty business logic and more flexibility and customization. Regarding this 90%, I was trying to stick to the DRY principle as much as I can. As long as controllers go, I have found resource_controller to really work, and I could get rid of all the controllers on that area, replacing them with a generic one. Now I'd like to know how to get the same with the views. On this app I have an overall, application.html.erb layout and then I must have another layout layer, common for all CRUD views and finally a "core" part: On index.html.erb all I need to generate a simple table with the fields and labels I indicate. For new and edit, also generic form edition, indicating labels and fields (with a possibility of providing custom fields if needed). I am not sure I will need show, but if I do it would be the same as new and edit. What plugins and tools (or even articles and general pointer) would help me to get that done? Thanks, Felipe.

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• Design pattern to integrate Rails with a Comet server

  - by empire29

  I have a Ruby on Rails (2.3.5) application and an APE (Ajax Push Engine) server. When records are created within the Rails application, i need to push the new record out on applicable channels to the APE server. Records can be created in the rails app by the traditional path through the controller's create action, or it can be created by several event machines that are constantly monitoring various inputstream and creating records when they see data that meets a certain criteria. It seems to me that the best/right place to put the code that pushes the data out to the APE server (which in turn pushes it out to the clients) is in the Model's after_create hook (since not all record creations will flow through the controller's create action). The final caveat is I want to push a piece of formatted HTML out to the APE server (rather than a JSON representation of the data). The reason I want to do this is 1) I already have logic to produce the desired layout in existing partials 2) I don't want to create a javascript implementation of the partials (javascript that takes a JSON object and creates all the HTML around it for presentation). This would quickly become a maintenance nightmare. The problem with this is it would require "rendering" partials from within the Model (which im having trouble doing anyhow because they don't seem to have access to Helpers when they're rendered in this manner). Anyhow - Just wondering what the right way to go about organizing all of this is. Thanks

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• How to extract data from F# list

  - by David White

  Following up my previous question, I'm slowly getting the hang of FParsec (though I do find it particularly hard to grok). My next newbie F# question is, how do I extract data from the list the parser creates? For example, I loaded the sample code from the previous question into a module called Parser.fs, and added a very simple unit test in a separate module (with the appropriate references). I'm using XUnit: open Xunit [<Fact>] let Parse_1_ShouldReturnListContaining1 () = let interim = Parser.parse("1") Assert.False(List.isEmpty(interim)) let head = interim.Head // I realise that I have only one item in the list this time Assert.Equal("1", ???) Interactively, when I execute parse "1" the response is: val it : Element list = [Number "1"] and by tweaking the list of valid operators, I can run parse "1+1" to get: val it : Element list = [Number "1"; Operator "+"; Number "1"] What do I need to put in place of my ??? in the snippet above? And how do I check that it is a Number, rather than an Operator, etc.?

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• Plotting a graph with GD

  - by Nayena

  Here it goes. I have been thinking about this for a long time, and havent really been able to put up a proper way to do it yet. I havent implemented anything yet, as im still designing the thing. The idea is that i crawl a website for internal links, i got this settled, its easy, but after the crawling, i end up with an array with lots of links, and how many times those particular link appears on the site that i crawled (and how they're connected). With this huge array, i want to draw a graph somehow. Assuming i can handle the data correctly, the real question here is how i can draw this in a image by the use of the GD library. I figured if theres less than 12 elements, i can align them up on a unit circle spacing them up as a circle and then connecting them accordingly, so anything up to 12 elements shouldn't be a problem, but if theres more than 12, it could be awesome getting them lined up like this Or well, thats just a rough drawing, but i guess its just to prove a point. So i'm here looking for guidance or tips towards getting the math down to getting the stuff lined up in a good way. I have previously made bar-graphs, so i have little experience doing math with GD. If possible, id prefer not using some plotter-library - in the end, it gives me a better understanding on how things are supposed to be.

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• jQuery tokeninput plugin + passing id to another tokeninput url

  - by Elson Solano

  I am using a jquery plugin called jQuery Tokeninput http://loopj.com/jquery-tokeninput/ and I am having a logic issue. var country_id = ""; jQuery("#demo-input-prevent-duplicates").tokenInput(host+"/forms/campaign_location.php?action=country", { theme: "facebook", hintText: "Enter a Country...", placeholder: "Enter a Country...", preventDuplicates: true, onAdd: function(item) { country_id = item.id; }, onDelete: function(){ hideElements(); }, tokenDelimiter: "|", }); My question here is how would I pass the value of country_id to the parameter of the below code. I'm not seeing how to do this one on the jquery tokeninput documentation. jQuery("#targ_state").tokenInput(host+"/forms/campaign_location.php?action=stateorprovince&cid="+country_id, { theme: "facebook", preventDuplicates: true, hintText: "Enter a State or Province...", placeholder: "Enter a State or Province..." }); If you'll look on this part of the code, I am passing the country_id that was generated above on the "onAdd". This doesn't work though. jQuery("#targ_state").tokenInput(host+"/forms/campaign_location.php?action=stateorprovince&cid="+country_id .... How would I do that one? Your help would be greatly appreciated and of course, rewarded! Thanks! :-)

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• Improve this generic abstract class

  - by Keivan

  I have the following abstract class design, I was wondering if anyone can suggest any improvements in terms of stronger enforcement of our requirements or simplifying implementing of the ControllerBase. //Dependency Provider base public abstract class ControllerBase<TContract, TType> where TType : TContract, class { public static TContract Instance { get { return ComponentFactory.GetComponent<TContract, TType>(); } } public TContract GetComponent<TContract, TType>() where TType : TContract, class { component = (TType)Activator.CreateInstance(typeof(TType), true); RegisterComponentInstance<TContract>(component); } } //Contract public interface IController { void DoThing(); } //Actual Class Logic public class Controller: ControllerBase<IController,Controller> { public void DoThing(); //internal constructor internal Controller(){} } //Usage public static void Main() { Controller.Instance.DoThing(); } The following facts should always be true, TType should always implement TContract (Enforced using a generic constraint) TContract must be an interface (Can't find a way to enforce it) TType shouldn't have public constructor, just an internal one, is there any way to Enforce that using ControllerBase? TType must be an concrete class (Didn't include New() as a generic constrain since the constructors should be marked as Internal)

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• Using entity framework to connect to multiple similar tables in .net MVC.

  - by Dite

  A relative newcomer to .net MVC2 and the entity framework, I am working on a project which requires a single web application, (C# .net 4), to connect to multiple different databases depending on the route of access, (ie subdomain). No problem with this in principle and all the logic is written to transform the subdomain into an entity connection and pass this through to the Entity Model. The problem comes with the fact that the different database whilst being largely similar in structure contain 3 or 4 unique tables bespoke to that instance. To my mind there are two ways to solve this issue, neither of which i am sure will be possible. 1/ Use a separate entity model for each database. -Attempts down this route have through up conflicts where table/sp names are the same across differnt db's, or implicit conversion errors when I try and put the different models in different namespaces. or 2/ Overwrite the classes which refer to the changeable database objects based on the value of a base controller property. -I have found nothing to suggest i can even do this. My question is if either of theser routes can ever work in principle or if i should just give up on the EF and connect to the dtabases directlky using ADO. Perhaps there is another way to solve this problem i haven't thought of? Thanks for any help...

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• Complex SQL design, help/advice needed

  - by eugeneK

  Hi, i have few questions for SQL gurus in here ... Briefly this is ads management system where user can define campaigns for different countries, categories, languages. I have few questions in mind so help me with what you can. Generally i'm using ASP.NET and i want to cache all result set of certain user once he asks for statistics for the first time, this way i will avoid large round-trips to server. any help is welcomed Click here for diagram with all details you need for my questions 1.Main issue of this application is to show to the user how many clicks/impressions were and how much money he spent on campaign. What is the easiest way to get this information for him? I will also include filtering by date, date ranges and few other params in this statistics table. 2.Other issue is what happens when user will try to edit campaign. Old campaign will die this means if user set 0.01$ as campaignPPU (pay-per-unit) and next day updates it to 0.05$ all will be reset to 0.05$. 3.If you could re-design some parts of table design so it would be more flexible and easier to modify, how would you do it? Thanks... sorry for so large job but it may interest some SQL guys in here

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• Strategies for dealing with Circular references caused by JPA relationships?

  - by ams

  I am trying to partition my application into modules by features packaged into separate jars such as feature-a.jar, feature-b.jar, ... etc. Individual feature jars such as feature-a.jar should contain all the code for a feature a including jpa entities, business logic, rest apis, unit tests, integration test ... etc. The problem I am running into is that bi-directional relationships between JPA entities cause circular references between the jar files. For example Customer entity should be in customer.jar and the Order should be in order.jar but Customer references order and order references customer making it hard to split them into separate jars / eclipse projects. Options I see for dealing with the circular dependencies in JPA entities: Option 1: Put all the entities into one jar / one project Option 2: Don't map certain bi-directianl relationships to avoid circular dependencies across projects. Questions: What rules / principles have you used to decide when to do bi-directional mapping vs. not? Have you been able to break jpa entities into their own projects / jar by features if so how did you avoid the circular dependencies issues?

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• Grails GORM rarely works in domain classes

  - by Vena

  I have many to many relationship between User and Organization. I want to delete user from all his organizations when the user is being deleted, so this is basically what I came up with: class User { ... def beforeDelete() { def user = User.get(id) Organization.all.each { it.removeFromMembers(user) it.save() } } } This surprisingly doesn't work because User.get(id) returns null even though the user with the given id is in the database, when I look at the log, no sql statement is even executed. So I tried to use load() method insted. ObjectNotFoundException is the result then. So I tried this as I was quite desperate: def user = User.find("from User as u where u.id = ?", [1L]) This, for some reason, works. But now, the line with it.removeFromMembers(user) throws NullPointerException. I tried to put this logic in my UserController and it works! Why is this? Why can't I do this in domain classes? This makes beforeDelete hook (and all the others too) pretty useless.

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• How do I make a HTTP POST request to an url from within a c++ dll?

  - by tjorriemorrie

  Hi, there's an open-source application I need to use. It allows you to use a custom dll. Unfortunately, I can't code c++; i don't like it; it don't want to learn it. I do know PHP very well however, thus you can see that I'll rather do my logic within a PHP application. Thus I'm thinking about posting the data from c++/dll to a url on my localhost. (i have my local server set up, that's not the problem). I need to post a large amount of variables (thus a POST and not GET request required). The return value will only be one (int)variable, either 0, 1 or 2. So I need a c++ function that: 1) will post variables to an url. 2) Wait for, and receive the answer. The data type can be in xml, soap, json, whatever, doesn't matter. Is there anyone that can write a little c++ http function for me? pretty please? ;)

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• How to limit setAccessible to only "legitimate" uses?

  - by polygenelubricants

  The more I learned about the power of setAccessible, the more astonished I am at what it can do. This is adapted from my answer to the question (Using reflection to change static final File.separatorChar for unit testing). import java.lang.reflect.*; public class EverythingIsTrue { static void setFinalStatic(Field field, Object newValue) throws Exception { field.setAccessible(true); Field modifiersField = Field.class.getDeclaredField("modifiers"); modifiersField.setAccessible(true); modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL); field.set(null, newValue); } public static void main(String args[]) throws Exception { setFinalStatic(Boolean.class.getField("FALSE"), true); System.out.format("Everything is %s", false); // "Everything is true" } } You can do truly outrageous stuff: public class UltimateAnswerToEverything { static Integer[] ultimateAnswer() { Integer[] ret = new Integer[256]; java.util.Arrays.fill(ret, 42); return ret; } public static void main(String args[]) throws Exception { EverythingIsTrue.setFinalStatic( Class.forName("java.lang.Integer$IntegerCache") .getDeclaredField("cache"), ultimateAnswer() ); System.out.format("6 * 9 = %d", 6 * 9); // "6 * 9 = 42" } } Presumably the API designers realize how abusable setAccessible can be, but must have conceded that it has legitimate uses to provide it. So my questions are: What are the truly legitimate uses for setAccessible? Could Java has been designed as to NOT have this need in the first place? What would the negative consequences (if any) of such design be? Can you restrict setAccessible to legitimate uses only? Is it only through SecurityManager? How does it work? Whitelist/blacklist, granularity, etc? Is it common to have to configure it in your applications?

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• What is the best / proper idiom in django for modifying a field during a .save() where you need to o

  - by MDBGuy

  Hi, say I've got: class LogModel(models.Model): message = models.CharField(max_length=512) class Assignment(models.Model): someperson = models.ForeignKey(SomeOtherModel) def save(self, *args, **kwargs): super(Assignment, self).save() old_person = #????? LogModel(message="%s is no longer assigned to %s"%(old_person, self).save() LogModel(message="%s is now assigned to %s"%(self.someperson, self).save() My goal is to save to LogModel some messages about who Assignment was assigned to. Notice that I need to know the old, presave value of this field. I have seen code that suggests, before super().save(), retrieve the instance from the database via primary key and grab the old value from there. This could work, but is a bit messy. In addition, I plan to eventually split this code out of the .save() method via signals - namely pre_save() and post_save(). Trying to use the above logic (Retrieve from the db in pre_save, make the log entry in post_save) seemingly fails here, as pre_save and post_save are two seperate methods. Perhaps in pre_save I can retrieve the old value and stick it on the model as an attribute? I was wondering if there was a common idiom for this. Thanks.

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• Android lifecycle of thread-based game

  - by ehehhh

  I ran into a bit of trouble while trying to get my game to work correctly after being put to the background by the user or a phone call for example. My app has a SurfaceView class called GameView, which has the onDraw() method to do all the necessary drawing for my game and two threads - one for calling the onDraw() and one for doing the necessary calculations for the game's logic. I succesfully implemented onPause() and onResume(). (I paused both threads when back button was pressed and resumed them after user cancelled in the AlertDialog.) Now I would like to have the game paused the same way when onStop() gets called. I put both threads on pause and saved my characters location in the savedInstanceState, but when I start my app again, no method gets called (I checked with Logcat). I believe onRestart() should be called first, then onStart() and then onResume(), but none of that happens. What am I doing wrong? (Didn't include any code, because it seems to be a problem of me not understanding the lifecycle, not a problem in code. If it seems necessary, I'll post the parts you request.)

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• Atomic operations on several transactionless external systems

  - by simendsjo

  Say you have an application connecting 3 different external systems. You need to update something in all 3. In case of a failure, you need to roll back the operations. This is not a hard thing to implement, but say operation 3 fails, and when rolling back, the rollback for operation 1 fails! Now the first external system is in an invalid state... I'm thinking a possible solution is to shut down the application and forcing a manual fix of the external system, but then again... It might already have used this information (and perhaps that's why it failed), or we might not have sufficient access. Or it might not even be a good way to rollback the action! Are there some good ways of handling such cases? EDIT: Some application details.. It's a multi user web application. Most of the work is done with scheduled jobs (through Quartz.Net), so most operations is run in it's own thread. Some user actions should trigger jobs that update several systems though. The external systems are somewhat unstable. I Was thinking of changing the application to use the Command and Unit Of Work pattern

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• Can Win32_NetworkAdapterConfiguration.EnableStatic() be used to set more than one IP address?

  - by Andrew J. Brehm

  I ran into this problem in a Visual Basic program that uses WMI but could confirm it in PowerShell. Apparently the EnableStatic() method can only be used to set one IP address, despite taking two parameters IP address(es) and subnetmask(s) that are arrays. I.e. $a=get-wmiobject win32_networkadapterconfiguration -computername myserver This gets me an array of all network adapters on "myserver". After selecting a specific one ($a=$a[14] in this case), I can run $a.EnableStatic() which has this signature System.Management.ManagementBaseObject EnableStatic(System.String[] IPAddress, System.String[] SubnetMask) I thought this implies that I could set several IP addresses like this: $ips="192.168.1.42","192.168.1.43" $a.EnableStatic($ips,"255.255.255.0") But this call fails. However, this call works: $a.EnableStatic($ips[0],"255.255.255.0") It looks to me as if EnableStatic() really takes two strings rather than two arrays of strings as parameters. In Visual Basic it's more complicated and arrays must be passed but the method appears to take into account only the first element of each array. Am I confused again or is there some logic here?

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• What's the best way to "shuffle" a table of database records?

  - by Darth

  Say that I have a table with a bunch of records, which I want to randomly present to users. I also want users to be able to paginate back and forth, so I have to perserve some sort of order, at least for a while. The application is basically only AJAX and it uses cache for already visited pages, so even if I always served random results, when the user tries to go back, he will get the previous page, because it will load from the local cache. The problem is, that if I return only random results, there might be some duplicates. Each page contains 6 results, so to prevent this, I'd have to do something like WHERE id NOT IN (1,2,3,4 ...) where I'd put all the previously loaded IDs. Huge downside of that solution is that it won't be possible to cache anything on the server side, as every user will request different data. Alternate solution might be to create another column for ordering the records, and shuffle it every insert time unit here. The problem here is, I'd need to set random number out of a sequence to every record in the table, which would take as many queries as there are records. I'm using Rails and MySQL if that's of any relevance.

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• Eliminate full table scan due to BETWEEN (and GROUP BY)

  - by Dave Jarvis

  Description According to the explain command, there is a range that is causing a query to perform a full table scan (160k rows). How do I keep the range condition and reduce the scanning? I expect the culprit to be: Y.YEAR BETWEEN 1900 AND 2009 AND Code Here is the code that has the range condition (the STATION_DISTRICT is likely superfluous). SELECT COUNT(1) as MEASUREMENTS, AVG(D.AMOUNT) as AMOUNT, Y.YEAR as YEAR, MAKEDATE(Y.YEAR,1) as AMOUNT_DATE FROM CITY C, STATION S, STATION_DISTRICT SD, YEAR_REF Y FORCE INDEX(YEAR_IDX), MONTH_REF M, DAILY D WHERE -- For a specific city ... -- C.ID = 10663 AND -- Find all the stations within a specific unit radius ... -- 6371.009 * SQRT( POW(RADIANS(C.LATITUDE_DECIMAL - S.LATITUDE_DECIMAL), 2) + (COS(RADIANS(C.LATITUDE_DECIMAL + S.LATITUDE_DECIMAL) / 2) * POW(RADIANS(C.LONGITUDE_DECIMAL - S.LONGITUDE_DECIMAL), 2)) ) <= 50 AND -- Get the station district identification for the matching station. -- S.STATION_DISTRICT_ID = SD.ID AND -- Gather all known years for that station ... -- Y.STATION_DISTRICT_ID = SD.ID AND -- The data before 1900 is shaky; insufficient after 2009. -- Y.YEAR BETWEEN 1900 AND 2009 AND -- Filtered by all known months ... -- M.YEAR_REF_ID = Y.ID AND -- Whittled down by category ... -- M.CATEGORY_ID = '003' AND -- Into the valid daily climate data. -- M.ID = D.MONTH_REF_ID AND D.DAILY_FLAG_ID <> 'M' GROUP BY Y.YEAR Update The SQL is performing a full table scan, which results in MySQL performing a "copy to tmp table", as shown here: +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ | 1 | SIMPLE | C | const | PRIMARY | PRIMARY | 4 | const | 1 | | | 1 | SIMPLE | Y | range | YEAR_IDX | YEAR_IDX | 4 | NULL | 160422 | Using where | | 1 | SIMPLE | SD | eq_ref | PRIMARY | PRIMARY | 4 | climate.Y.STATION_DISTRICT_ID | 1 | Using index | | 1 | SIMPLE | S | eq_ref | PRIMARY | PRIMARY | 4 | climate.SD.ID | 1 | Using where | | 1 | SIMPLE | M | ref | PRIMARY,YEAR_REF_IDX,CATEGORY_IDX | YEAR_REF_IDX | 8 | climate.Y.ID | 54 | Using where | | 1 | SIMPLE | D | ref | INDEX | INDEX | 8 | climate.M.ID | 11 | Using where | +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ Related http://dev.mysql.com/doc/refman/5.0/en/how-to-avoid-table-scan.html http://dev.mysql.com/doc/refman/5.0/en/where-optimizations.html http://stackoverflow.com/questions/557425/optimize-sql-that-uses-between-clause Thank you!

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• .NET Web Serivce hydrate custom class

  - by row1

  I am consuming an external C# Web Service method which returns a simple calculation result object like this: [Serializable] public class CalculationResult { public string Name { get; set; } public string Unit { get; set; } public decimal? Value { get; set; } } When I add a Web Reference to this service in my ASP .NET project Visual Studio is kind enough to generate a matching class so I can easily consume and work with it. I am using Castle Windsor and I may want to plug in other method of getting a calculation result object, so I want a common class CalculationResult (or ICalculationResult) in my solution which all my objects can work with, this will always match the object returned from the external Web Service 1:1. Is there anyway I can tell my Web Service client to hydrate a particular class instead of its generated one? I would rather not do it manually: foreach(var fromService in calcuationResultsFromService) { ICalculationResult calculationResult = new CalculationResult() { Name = fromService.Name }; yield return calculationResult; } Edit: I am happy to use a Service Reference type instead of the older Web Reference.

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• AJAX or a server side framework?

  - by Romansky

  I am working with a friend on building a web site, in general this web site will be a custom web app along with a very custom social network type of thing.. Currently I have a mock-up site that uses simple PHP with AJAX and JSON and JQUERY and I love how it works, I love the way it all fits together. But for a mock-up I did not implement any of the Social Network design patterns such as a login, rating, groups etc.. This brought me to a higher level of decision making requirement, I need to decide if I want to develop all this functionality by hand or use some kind of a framework. I spent this entire day researching, and it would seem that using Drupal and such frameworks will make the Social Network part easy (overlooking the customization requirement for now..) but will make client side Web App development less so. I found some other frameworks that are more developer friendly (customizable) such as Zend and Symfony etc.. but these seem to take allot of the power from the client and implement it in the server side, to me this seems a waste (and an unjustified performance bottleneck) .. Finally I found Aptana Jaxer framework that seems to think the same way I feel. That said it seems a bit under-developed, I didn't find modules for a social network and the community around it seems thin.. (searching Jaxer in StackOverflow returns few results) So other then making server side DB comm a bit simpler it does not help me greatly.. My requirements are a good facility to develop web apps on while containing all the user centric logic usually used for social networks in advance. What would you recommend? EDIT: OK, lats fine tune this question, after considering this abit further, is there a good down loadable source of a social network site in PHP that I can work around in building my web app? (I really like using JQUERY AJAX JSON etc..)

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• What single software development tool do you think holds the most value?

  - by Phobis

  Every day I realize how much I love Visual Studio for .NET development.... but, I believe that Resharper, may hold a value that surpasses Visual Studio's (I am using VS 2005 for WPF/WCF development). I decided it would be great to compile a list of the most valuable tools for software development. These can be applications/plug-ins anything that you think holds GREAT value. Also, please explain the benefits of the tool that you are posting. Resharper: Intergrated Unit testing "Camel Hump" code auto completion Find "usings" (inverse of "Go to Deceleration") Code formating and member rearranging Assembly and namespace inclusion (based on your code) Check for common optimizations and possible bugs in code and suggests/rewrites the code for you (things like null checking, redundant delegate creation, inverting if statements, etc...); Tells you when code and be more generic (may suggest things like "use this interface instead" if your code never refers to something specific on an object) Helps you see code that is not being used and will clean any unused members. File structure view helps you jump around the regions of your file (this is really awesome and clean). Class searching (you can use things like camel humps) Asks you which partial file to open once you find a class. It also has it's own plugin support, so you can do things like FxCop, documentation and relfector (all free). This thing has so much I don't think I hit 10% of it yet :) [When I get time, I will try to add more... feel free to help me out]

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• Open closed prinicple, problem

  - by Marcus

  Hi, I'm trying to apply OCP to a code snippet I have that in it's current state is really smelly, but I feel I'm not getting all the way to the end. Current code: public abstract class SomeObject {} public class SpecificObject1 : SomeObject {} public class SpecificObject2 : SomeObject {} // Smelly code public class Model { public void Store(SomeObject someObject) { if (someObject is SpecificObject1) {} else if (someObject is SpecificObject2) {} } } That is really ugly, my new approach looks like this: // No so smelly code public class Model { public void Store(SomeObject someObject) { throw new Expception("Not allowed!"); } public void Store(SpecificObject1 someObject) {} public void Store(SpecificObject2 someObject) {} } When a new SomeObject type comes along I must implement how that specific object is stored, this will break OCP cause I need to alter the Model-class. To move the store logic to SomeObject also feels wrong cause then I will violate SRP (?), becuase in this case the SomeObject is almost like a DTO, it's resposibility it not how to know to store itself. If a new implementation to SomeObject comes along who's store implementation is missing I will get a runtime error due to exception in Store method in Model class, it also feels like a code smell. This is because calling code will in the form of IEnumerable<SomeObject> sequence; I will not know the specific types of the sequence objects. I can't seem to grasp the OCP-concept. Anyone has any concrete examples or links that is a bit more than just some Car/Fruit example?

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• MySQL query against pseudo-key-value pair data in WordPress custom query

  - by andrevr

  I'm writing a custom WordPress query to use some of the data which the Woothemes Diarise theme creates. Diarise is an event planner theme with calendar blah, blah... and uses custom fields to store the event start and end dates in WP custom fields in the *wp_postmeta* table, which implements a key-value store. So for each post in the "event" category, there are 2 records in *wp_postmeta*, named *event_start_date* and *event_end_date* that I'm interested in. The task is to compare a tourist's arrival and departure dates with the start and end dates of events, yielding a what's on list of events available. We thought we'd killed it with a grand flash of logic, that goes like this: Disregard any event that ends before the tourist arrives, and any that begin after the departure date. I wrote this query: SELECT wposts.* FROM wp_posts wposts LEFT JOIN wp_postmeta wpostmeta ON wposts.ID = wpostmeta.post_id LEFT JOIN wp_term_relationships ON (wposts.ID = wp_term_relationships.object_id) LEFT JOIN wp_term_taxonomy ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id) WHERE wp_term_taxonomy.taxonomy = 'category' AND wp_term_taxonomy.term_id IN(3,4) AND ( wpostmeta.meta_key = 'event_start_date' AND NOT ( concat(subst(wpostmeta.meta_value,7,4),'-',subst(wpostmeta.meta_value,4,2),'-',subst(wpostmeta.meta_value,1,2) > '2010-07-31' ) ) AND ( wpostmeta.meta_key = 'event_end_date' AND NOT ( concat(subst(wpostmeta.meta_value,7,4),'-',subst(wpostmeta.meta_value,4,2),'-',subst(wpostmeta.meta_value,1,2) < '2010-05-01' ) ) ) ORDER BY wpostmeta.meta_value ASC And, of course it returns no records. The problem I believe is in the dual reference to wpostmeta.meta_key, but how to get around that?

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• Mutually beneficial IP/copyright clauses for contract-based freelance work

  - by Nathan de Vries

  I have a copyright section in the contract I give to my clients stating that I retain copyright on any works produced during my work for them as an independent contractor. This is most definitely not intended to place arbitrary restrictions on my clients, but rather to maintain my ability to decide on how the software I create is licensed and distributed. Almost every project I work on results in at least one part of it being released as open source. Every project I work on makes use of third-party software released in the same fashion, so returning the favour is something I would like to continue doing. Unfortunately, the contract is not so clear when it comes to defining the rights of the client in the use of said software. I mention that the code will be licensed to them, but do not mention specifics about exclusivity, ability to produce derivatives etc. As such, a client has raised concerns about the copyright section of my contract, and has suggested that I reword it such that all copyrights are transferred entirely to the client on final payment for the project. This will almost certainly reduce my ability to distribute the software I have created; I would much prefer to find a more mutually beneficial agreement where both our concerns are appeased. Are there any tried and true approaches to licensing software in this kind of situation? To summarise: I want to maintain the ability to license (parts of) the software under my own terms, independently of my relationship with the client; with some guarantee to the client that no trade-secrets or critical business logic will be shared; giving them the ability to re-use my code in their future projects; but not necessarily letting them sell it (I'm not sure about this, though...what happens if they sell their business and the software along with it?) I realise that everyone's feedback is going to be prefixed with "IANAL", however I appreciate any thoughts you might have on the matter.

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• Resources for setting up a Visual Studio/C++ development environment

  - by Tom H.

  I haven't done much "front-end" development in about 15 years since moving to database development. I'm planning to start work on a personal project using C++ and since I already have MSDN I'll probably end up doing it in Visual Studio 2010. I'm thinking about using Subversion as a version control system eventually. Of course, I'd like to get up and running as quickly as I can, but I'd also like to avoid any pitfalls from a poorly organized project environment. So, my question is, are there any good resources with common best practices for setting up a development environment? I'm thinking along the lines of where to break down a solution into multiple projects if necessary, how to set up a unit testing process, organizing resources, directories, etc. Are there any great add-ons that I should make sure I have set up from the start? Most tutorials just have one simple project, type in your code and click on build to see that your new application says, "Hello World!". This will be a Windows application with several DLLs as well (no web development), so there doesn't need to be a deploy to a web server kind of process. Mostly I just want to make sure that I don't miss anything big and then have to extensively refactor because of it. Thanks!

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