Search Results

Search found 9011 results on 361 pages for 'common'.

Page 324/361 | < Previous Page | 320 321 322 323 324 325 326 327 328 329 330 331  | Next Page >

• Best method for converting several sets of numbers with several different ratios

  - by C Patton

  I'm working on an open-source harm reduction application for opioid addicts. One of the features in this application is the conversion (in mg/mcg) between common opioids, so people don't overdose by accident. If you're morally against opioid addiction and wouldn't respond because of your morals, please consider that this application is for HARM REDUCTION.. So people don't end up dead. I have this data.. 3mg morphine IV = 10mcg fentanyl IV 2mg morphine oral = 1mg oxycodone oral 3mg oral morphine = 1mg oxymorphone oral 7.0mg morphine oral = 1mg hydromorphone oral 1mg morphine iv = .10mg oxymorphone iv 1mg morphine oral = 1mg hydrocodone oral 1mg morphine oral = 6.67mg codeine oral 1mg morphine oral = .10mg methadone oral And I have a textbox that is the source dosage in mg (a double) that the user can enter in. Underneath this, I have radio boxes for the source substance (ie: morphine) and the destination substance (ie oxycodone) for conversion.. I've been trying to think of the most efficient way to do this, but nearly every seems sloppy. If I were to do something like public static double MorphinetoOxycodone(string morphineValue) { double morphine = Double.Parse(morphineValue); return (morphine / 2 ); } I would also have to make a function for OxycodonetoMorphine, OxycodonetoCodeine, etc.. and then would end up with dozens functions.. There must be an easier way than this that I'm missing. If you'll notice, all of my conversions use morphine as the base value.. what might be the easiest way to use the morphine value to convert one opioid to another? For example, if 1mg morphine oral is equal to 1mg hydrocodone and 1mg morphine oral is equal to .10mg methadone, wouldn't I just multiply 1*.10 to get the hydrocodone-methadone value? Implementing this idea is what I'm having the most trouble with. Any help would be GREATLY appreciated.. and if you'd like, I would add your name/nickname to the credits in this program. It's possible that many, many people around the world will use this (I'm translating it into several languages as well) and to know that your work could've helped an addict from dying.. I think that's a great thing :) -cory

  Read the article

• Classes to Entities; Like-class inheritence problems

  - by Stacey

  Beyond work, some friends and I are trying to build a game of sorts; The way we structure some of it works pretty well for a normal object oriented approach, but as most developers will attest this does not always translate itself well into a database persistent approach. This is not the absolute layout of what we have, it is just a sample model given for sake of representation. The whole project is being done in C# 4.0, and we have every intention of using Entity Framework 4.0 (unless Fluent nHibernate can really offer us something we outright cannot do in EF). One of the problems we keep running across is inheriting things in database models. Using the Entity Framework designer, I can draw the same code I have below; but I'm sure it is pretty obvious that it doesn't work like it is expected to. To clarify a little bit; 'Items' have bonuses, which can be of anything. Therefore, every part of the game must derive from something similar so that no matter what is 'changed' it is all at a basic enough level to be hooked into. Sounds fairly simple and straightforward, right? So then, we inherit everything that pertains to the game from 'Unit'. Weights, Measures, Random (think like dice, maybe?), and there will be other such entities. Some of them are similar, but in code they will each react differently. We're having a really big problem with abstracting this kind of thing into a database model. Without 'Enum' support, it is proving difficult to translate into multiple tables that still share a common listing. One solution we've depicted is to use a 'key ring' type approach, where everything that attaches to a character is stored on a 'Ring' with a 'Key', where each Key has a Value that represents a type. This works functionally but we've discovered it becomes very sluggish and performs poorly. We also dislike this approach because it begins to feel as if everything is 'dumped' into one class; which makes management and logical structure difficult to adhere to. I was hoping someone else might have some ideas on what I could do with this problem. It's really driving me up the wall; To summarize; the goal is to build a type (Unit) that can be used as a base type (Table per Type) for generic reference across a relatively global scope, without having to dump everything into a single collection. I can use an Interface to determine actual behavior so that isn't too big of an issue. This is 'roughly' the same idea expressed in the Entity Framework.

  Read the article

• Internet Explorer buggy when accessing a custom weblogic provider

  - by James

  I've created a custom Weblogic Security Authentication Provider on version 10.3 that includes a custom login module to validate users. As part of the provider, I've implemented the ServletAuthenticationFilter and added one filter. The filter acts as a common log on page for all the applications within the domain. When we access any secured URLs by entering them in the address bar, this works fine in IE and Firefox. But when we bookmark the link in IE an odd thing happens. If I click the bookmark, you will see our log on page, then after you've successfully logged into the system the basic auth page will display, even though the user is already authenticated. This never happens in Firefox, only IE. It's also intermittent. 1 time out of 5 IE will correctly redirect and not show the basic auth window. Firefox and Opera will correctly redirect everytime. We've captured the response headers and compared the success and failures, they are identical. final boolean isAuthenticated = authenticateUser(userName, password, req); // Send user on to the original URL if (isAuthenticated) { res.sendRedirect(targetURL); return; } As you can see, once the user is authenticated I do a redirect to the original URL. Is there a step I'm missing? The authenticateUser() method is taken verbatim from an example in Oracle's documents. private boolean authenticateUser(final String userName, final String password, HttpServletRequest request) { boolean results; try { ServletAuthentication.login(new CallbackHandler() { @Override public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException { for (Callback callback : callbacks) { if (callback instanceof NameCallback) { NameCallback nameCallback = (NameCallback) callback; nameCallback.setName(userName); } if (callback instanceof PasswordCallback) { PasswordCallback passwordCallback = (PasswordCallback) callback; passwordCallback.setPassword(password.toCharArray()); } } } }, request); results = true; } catch (LoginException e) { results = false; } return results; I am asking the question here because I don't know if the issue is with the Weblogic config or the code. If this question is more suited to ServerFault please let me know and I will post there. It is odd that it works everytime in Firefox and Opera but not in Internet Explorer. I wish that not using Internet Explorer was an option but it is currently the company standard. Any help or direction would be appreciated. I have tested against IE 6 & 8 and deployed the custom provider on 3 different environments and I can still reproduce the bug.

  Read the article

• Function Point Analysis -- a seriously overestimating technique?

  - by kizzx2

  I know questions about FPA has been asked numerous times before, but this time I'm taking a more analytical angle at it, backed up with data. 1. First, some data This question is based on a tutorial. He had a "Sample Count" section where he demonstrated it step by step. You can see some screenshots of his sample application here. In the end, he calculated the unadjusted FP to be 99. There is another article on InformIT with industry data on typical hour/FP. It ranges from 2 hours/FP to 27.4 hours/FP. Let's try to stick with 2 for the moment (since SO readers are probably the more efficient crowd :p). 2. Reality check!? Now just check out the screenshots again. Do a little math here 99 * 2 = 198 hours 198 hours / 40 hours per week = 5 weeks Seriously? That sample application is going to take 5 weeks to implement? Is it just my feeling that it wouldn't take any decent programmer longer than one week (I"m not even saying weekend) to have it completed? Now let's try estimating the cost of the project. We'll use New York's minimum wage at the moment (Wikipedia), which is $7.25 198 * 7.25 = $1435.5 From what I could see from the screenshots, this application is a small excel-improvement app. I could have bought MS Office Pro for 200 bucks which gives me greater interoperability (.xls files) and flexibility (spreadsheets). (For the record, that same Web site has another article discussing productivity. It seems like they typically use 4.2 hours/FP, which gives us even more shocking stats: 99 * 4.2 = 415 hours = 10 weeks = almost 3 whopping months! 415 hours * $7.25 = $3000 zomg (That's even assuming that all our poor coders get the minimum wage!) 3. Am I missing something here? Right now, I could come up with several possible explanation: FPA is really only suited for bigger projects (1000+ FPs) so it becomes extremely inaccurate at smaller scale. The hours/FP metric fluctuates abruptly from team to team, project to project. For a small project like this, we could have used something like 0.5 hour/FP or something. (Now this kind of makes the whole estimation thing pointless, unless my firm does the same type of projects for several years with the same team, not really common.) From my experience with several software metrics, Function Point is really not a lightweight metric. If the hour/FP thing fluctuates so much, then what's the point, maybe I could have gone with User Story Points which is a lot faster to get and arguably almost as uncertain. What would be the FP experts' answers to this?

  Read the article

• How and why do I set up a C# build machine?

  - by mmr

  Hi all, I'm working with a small (4 person) development team on a C# project. I've proposed setting up a build machine which will do nightly builds and tests of the project, because I understand that this is a Good Thing. Trouble is, we don't have a whole lot of budget here, so I have to justify the expense to the powers that be. So I want to know: What kind of tools/licenses will I need? Right now, we use Visual Studio and Smart Assembly to build, and Perforce for source control. Will I need something else, or is there an equivalent of a cron job for running automated scripts? What, exactly, will this get me, other than an indication of a broken build? Should I set up test projects in this solution (sln file) that will be run by these scripts, so I can have particular functions tested? We have, at the moment, two such tests, because we haven't had the time (or frankly, the experience) to make good unit tests. What kind of hardware will I need for this? Once a build has been finished and tested, is it a common practice to put that build up on an ftp site or have some other way for internal access? The idea is that this machine makes the build, and we all go to it, but can make debug builds if we have to. How often should we make this kind of build? How is space managed? If we make nightly builds, should we keep around all the old builds, or start to ditch them after about a week or so? Is there anything else I'm not seeing here? I realize that this is a very large topic, and I'm just starting out. I couldn't find a duplicate of this question here, and if there's a book out there I should just get, please let me know. EDIT: I finally got it to work! Hudson is completely fantastic, and FxCop is showing that some features we thought were implemented were actually incomplete. We also had to change the installer type from Old-And-Busted vdproj to New Hotness WiX. Basically, for those who are paying attention, if you can run your build from the command line, then you can put it into hudson. Making the build run from the command line via MSBuild is a useful exercise in itself, because it forces your tools to be current.

  Read the article

• Is the recent trend toward widescreen (16:9) computer monitors a plus or minus for programmers?

  - by DanM

  It's almost gotten to the point where you can't buy a conventional (4:3) monitor anymore. Pretty much everything is widescreen. This is fine for watching movies or TV, but is it good or bad for programming? My initial thoughts on the issue are that widescreens are a net negative for programmers. Here are some of the disadvantages I see: Poor space utiliziation One disadvantage of widescreens you can't argue with is that they offer poor space utilization for the amount of total pixels you get. For example, my Thinkpad, which I bought just before the widescreen craze, has a 15" monitor with a native resolution of 1600 x 1200. The newer 15.4" Thinkpads run at most 1680 x 1050. So (if you do the math) you get fewer pixels in a wider (but not shorter) package. With desktop monitors, you pay a price in terms of desk space used. Two 1680 x 1050 monitors will simply take up more of your desk than two 1600 x 1200 monitors (assuming equal dot pitch). More scrolling If you compare a 1680 x 1050 monitor to a 1600 x 1200 monitor, you get 80 extra pixels of width but 150 fewer pixels of height. The height reduction means you lose approximately 11 lines of code. That's less you can see on the screen at one time and more scrolling you have to do. This harms productivity, maybe not dramatically, but insidiously. Less room for wide panels Widescreens also mean you lose space for wide but short panels common in programming environments. If you use Visual Studio, for example, your code window will be that much shorter when viewing the Find Results, Task List, or Error List (all of which I use frequently). This isn't to say the 80 pixels of extra width you get with widescreen would never be useful, but I tend to keep my lines of code short, so seeing more lines would be more valuable to me than seeing fewer, longer lines. What do you think? Do you agree/disagree? Are you now using one or more widescreen monitors for development? What resolution are you running on each? Do you ever miss the height of the traditional 4:3 monitor? Would you complain if your monitors were one inch narrower but two inches taller?

  Read the article

• XSD: xs:sequence & xs:choice combination for xs:extension elements?

  - by bguiz

  Hi, My question is about defining an XML schema that will validate the following sample XML: <rules> <other>...</other> <bool>...</bool> <other>...</other> <string>...</string> <other>...</other> </rules> The order of the child nodes does not matter. The cardinality of the child nodes is 0..unbounded. All the child elements of the rules node have a common base type, rule, like so: <xs:complexType name="booleanRule"> <xs:complexContent> <xs:extension base="rule"> ... </xs:extension> </xs:complexContent> </xs:complexType> <xs:complexType name="stringFilterRule"> <xs:complexContent> <xs:extension base="filterRule"> ... </xs:extension> </xs:complexContent> </xs:complexType> My current attempt at defining the schema for the rules node is below. However, Can I nest xs:choice within xs:sequence? If, where do I specify the maxOccurs="unbounded" attribute? Is there a better way to do this, such as an xs:sequence which specifies only the base type of its child elements? <xs:element name="rules"> <xs:complexType> <xs:sequence> <xs:choice> <xs:element name="bool" type="booleanRule" /> <xs:element name="string" type="stringRule" /> <xs:element name="other" type="someOtherRule" /> </xs:choice> </xs:sequence> </xs:complexType> </xs:element>

  Read the article

• How do I display a jquery dialog box before the entire page is loaded?

  - by obarshay

  On my site a number of operations can take a long time to complete. When I know a page will take a while to load, I would like to display a progress indicator while the page is loading. Ideally I would like to say something along the lines of: $("#dialog").show("progress.php"); and have that overlay on top of the page that is being loaded (disappearing after the operation is completed). Coding the progress bar and displaying progress is not an issue, the issue is getting a progress indicator to pop up WHILE the page is being loaded. I have been trying to use JQuery's dialogs for this but they only appear after the page is already loaded. This has to be a common problem but I am not familiar enough with JavaScript to know the best way to do this. Here's simple example to illustrate the problem. The code below fails to display the dialog box before the 20 second pause is up. I have tried in Chrome and Firefox. In fact I don't even see the "Please Wait..." text. Here's the code I am using: <html> <head> <link type="text/css" href="http://jqueryui.com/latest/themes/base/ui.all.css" rel="stylesheet" /> <script type="text/javascript" src="http://jqueryui.com/latest/jquery-1.3.2.js"></script> <script type="text/javascript" src="http://jqueryui.com/latest/ui/ui.core.js"></script> <script type="text/javascript" src="http://jqueryui.com/latest/ui/ui.dialog.js"></script> </head> <body> <div id="please-wait">My Dialog</div> <script type="text/javascript"> $("#please-wait").dialog(); </script> <?php flush(); echo "Waiting..."; sleep(20); ?> </body> </html>

  Read the article

• XML - how to use namespace prefixes

  - by Asbie

  I have this XML at http://localhost/file.xml: <?xml version="1.0" encoding="utf-8"?> <val:Root xmlns:val="http://www.hw-group.com/XMLSchema/ste/values.xsd"> <Agent> <Version>2.0.3</Version> <XmlVer>1.01</XmlVer> <DeviceName>HWg-STE</DeviceName> <Model>33</Model> <vendor_id>0</vendor_id> <MAC>00:0A:DA:01:DA:DA</MAC> <IP>192.168.1.1</IP> <MASK>255.255.255.0</MASK> <sys_name>HWg-STE</sys_name> <sys_location/> <sys_contact> HWg-STE:For more information try http://www.hw-group.com </sys_contact> </Agent> <SenSet> <Entry> <ID>215</ID> <Name>Home</Name> <Units>C</Units> <Value>27.7</Value> <Min>10.0</Min> <Max>40.0</Max> <Hyst>0.0</Hyst> <EmailSMS>1</EmailSMS> <State>1</State> </Entry> </SenSet> </val:Root> I am trying to read this from my c# code: static void Main(string[] args) { var xmlDoc = new XmlDocument(); xmlDoc.Load("http://localhost/file.xml"); XmlElement root = xmlDoc.DocumentElement; // Create an XmlNamespaceManager to resolve the default namespace. XmlNamespaceManager nsmgr = new XmlNamespaceManager(xmlDoc.NameTable); nsmgr.AddNamespace("val", "http://www.hw-group.com/XMLSchema/ste/values.xsd"); XmlNodeList nodes = root.SelectNodes("/val:SenSet/val:Entry"); foreach (XmlNode node in nodes) { string name = node["Name"].InnerText; string value = node["Value"].InnerText; Console.Write("name\t{0}\value\t{1}", name, value); } Console.ReadKey(); } } Problem is that the node is empty. I understand this is a common newbie problem when reading XML, still not able to solve what I am doing wrong, probably something with the Namespace "val" ?

  Read the article

• What are the weaknesses of this user authentication method?

  - by byronh

  I'm developing my own PHP framework. It seems all the security articles I have read use vastly different methods for user authentication than I do so I could use some help in finding security holes. Some information that might be useful before I start. I use mod_rewrite for my MVC url's. Passwords are sha1 and md5 encrypted with 24 character salt unique to each user. mysql_real_escape_string and/or variable typecasting on everything going in, and htmlspecialchars on everything coming out. Step-by step process: Top of every page: session_start(); session_regenerate_id(); If user logs in via login form, generate new random token to put in user's MySQL row. Hash is generated based on user's salt (from when they first registered) and the new token. Store the hash and plaintext username in session variables, and duplicate in cookies if 'Remember me' is checked. On every page, check for cookies. If cookies set, copy their values into session variables. Then compare $_SESSION['name'] and $_SESSION['hash'] against MySQL database. Destroy all cookies and session variables if they don't match so they have to log in again. If login is valid, some of the user's information from the MySQL database is stored in an array for easy access. So far, I've assumed that this array is clean so when limiting user access I refer to user.rank and deny access if it's below what's required for that page. I've tried to test all the common attacks like XSS and CSRF, but maybe I'm just not good enough at hacking my own site! My system seems way too simple for it to actually be secure (the security code is only 100 lines long). What am I missing? I've also spent alot of time searching for the vulnerabilities with mysql_real_escape string but I haven't found any information that is up-to-date (everything is from several years ago at least and has apparently been fixed). All I know is that the problem was something to do with encoding. If that problem still exists today, how can I avoid it? Any help will be much appreciated.

  Read the article

• C++ adding friend to a template class in order to typecast

  - by user1835359

  I'm currently reading "Effective C++" and there is a chapter that contains code similiar to this: template <typename T> class Num { public: Num(int n) { ... } }; template <typename T> Num<T> operator*(const Num<T>& lhs, const Num<T>& rhs) { ... } Num<int> n = 5 * Num<int>(10); The book says that this won't work (and indeed it doesn't) because you can't expect the compiler to use implicit typecasting to specialize a template. As a soluting it is suggested to use the "friend" syntax to define the function inside the class. //It works template <typename T> class Num { public: Num(int n) { ... } friend Num operator*(const Num& lhs, const Num& rhs) { ... } }; Num<int> n = 5 * Num<int>(10); And the book suggests to use this friend-declaration thing whenever I need implicit conversion to a template class type. And it all seems to make sense. But why can't I get the same example working with a common function, not an operator? template <typename T> class Num { public: Num(int n) { ... } friend void doFoo(const Num& lhs) { ... } }; doFoo(5); This time the compiler complaints that he can't find any 'doFoo' at all. And if i declare the doFoo outside the class, i get the reasonable mismatched types error. Seems like the "friend ..." part is just being ignored. So is there a problem with my understanding? What is the difference between a function and an operator in this case?

  Read the article

• Recommendations for a C++ polymorphic, seekable, binary I/O interface

  - by Trevor Robinson

  I've been using std::istream and ostream as a polymorphic interface for random-access binary I/O in C++, but it seems suboptimal in numerous ways: 64-bit seeks are non-portable and error-prone due to streampos/streamoff limitations; currently using boost/iostreams/positioning.hpp as a workaround, but it requires vigilance Missing operations such as truncating or extending a file (ala POSIX ftruncate) Inconsistency between concrete implementations; e.g. stringstream has independent get/put positions whereas filestream does not Inconsistency between platform implementations; e.g. behavior of seeking pass the end of a file or usage of failbit/badbit on errors Don't need all the formatting facilities of stream or possibly even the buffering of streambuf streambuf error reporting (i.e. exceptions vs. returning an error indicator) is supposedly implementation-dependent in practice I like the simplified interface provided by the Boost.Iostreams Device concept, but it's provided as function templates rather than a polymorphic class. (There is a device class, but it's not polymorphic and is just an implementation helper class not necessarily used by the supplied device implementations.) I'm primarily using large disk files, but I really want polymorphism so I can easily substitute alternate implementations (e.g. use stringstream instead of fstream for unit tests) without all the complexity and compile-time coupling of deep template instantiation. Does anyone have any recommendations of a standard approach to this? It seems like a common situation, so I don't want to invent my own interfaces unnecessarily. As an example, something like java.nio.FileChannel seems ideal. My best solution so far is to put a thin polymorphic layer on top of Boost.Iostreams devices. For example: class my_istream { public: virtual std::streampos seek(stream_offset off, std::ios_base::seekdir way) = 0; virtual std::streamsize read(char* s, std::streamsize n) = 0; virtual void close() = 0; }; template <class T> class boost_istream : public my_istream { public: boost_istream(const T& device) : m_device(device) { } virtual std::streampos seek(stream_offset off, std::ios_base::seekdir way) { return boost::iostreams::seek(m_device, off, way); } virtual std::streamsize read(char* s, std::streamsize n) { return boost::iostreams::read(m_device, s, n); } virtual void close() { boost::iostreams::close(m_device); } private: T m_device; };

  Read the article

• Question about Architecture for Viewing Images in ASP.NET MVC App

  - by Charlie Flowers

  I have an approach in mind for an image viewer in a web app, and want to get a sanity check and any thoughts you stackoverflowers might have. Here's the whirlwind nutshell summary: I'm working on an ASP.NET MVC application that will run in my company's retail stores. Even though it is a web application, we own the store machines and have control over them. We have a "windows agent" running on the store machine which we can talk to from the browser via javascript (it is a WCF service, and our web app has permission to talk to it from the browser). One of the web pages needs to be an "image viewer" page with some common things like Rotate & Zoom. Now, there are some WebForms controls that offer Rotate and Zoom. However, they take up server resources and generate a good bit of traffic between the server and the browser. For example, the Rotate function would cause an ajax call to the server, which would then generate a new image written to a .NET Canvas object, which would then be written to a file on the server, which would then be returned from the ajax call and refreshed inside the browser. Normally, that's a pretty good way of doing things. But in our case, we have code running on the store machine that we can communicate with. This leads me to consider the following approach: When the user asks to view an image, we tell our "windows agent" to download it from our image server to the store machine. We then redirect our browser to our image viewer page, which will pull the image from the local file we just wrote to the store machine. When the user clicks "Rotate", we cause JavaScript code in the browser to call our "windows agent" software, asking it to perform the "Rotate" function. The "windows agent" does the rotation using the same kind of imaging control that would formerly have been used on the server, but it does so now on the store machine. Javascript in the browser then refreshes the image on the page to show the newly rotated image. Zoom and similar features would be implemented the same way. This seems to be much more efficient, scalable, and responsive for the end-users. However, I've never heard of anything like it being done, mostly because it's rare to have this combination of a web app plus a "windows agent" on the client machine. What do you think? Feasible? Reasonable? Any pitfalls I overlooked or improvements / suggestions you can see? Has anyone done anything like this who would like to offer the wisdom of experience? Thanks!

  Read the article

• Separate specific #ifdef branches

  - by detly

  In short: I want to generate two different source trees from the current one, based only on one preprocessor macro being defined and another being undefined, with no other changes to the source. If you are interested, here is my story... In the beginning, my code was clean. Then we made a new product, and yea, it was better. But the code saw only the same peripheral devices, so we could keep the same code. Well, almost. There was one little condition that needed to be changed, so I added: #if defined(PRODUCT_A) condition = checkCat(); #elif defined(PRODUCT_B) condition = checkCat() && checkHat(); #endif ...to one and only one source file. In the general all-source-files-include-this header file, I had: #if !(defined(PRODUCT_A)||defined(PRODUCT_B)) #error "Don't make me replace you with a small shell script. RTFM." #endif ...so that people couldn't compile it unless they explicitly defined a product type. All was well. Oh... except that modifications were made, components changed, and since the new hardware worked better we could significantly re-write the control systems. Now when I look upon the face of the code, there are more than 60 separate areas delineated by either: #ifdef PRODUCT_A ... #else ... #endif ...or the same, but for PRODUCT_B. Or even: #if defined(PRODUCT_A) ... #elif defined(PRODUCT_B) ... #endif And of course, sometimes sanity took a longer holiday and: #ifdef PRODUCT_A ... #endif #ifdef PRODUCT_B ... #endif These conditions wrap anywhere from one to two hundred lines (you'd think that the last one could be done by switching header files, but the function names need to be the same). This is insane. I would be better off maintaining two separate product-based branches in the source repo and porting any common changes. I realise this now. Is there something that can generate the two different source trees I need, based only on PRODUCT_A being defined and PRODUCT_B being undefined (and vice-versa), without touching anything else (ie. no header inclusion, no macro expansion, etc)?

  Read the article

• Modular GWT design concerns

  - by GlGuru

  Hi, I have a couple of questions regarding a modular GWT based application framework. I have some ideas about them but being new to the field of web development I feel they are far from ideal. I'd appreciate a few comments and suggestions in this regard. Here are my questions: I am developing a framework which will allow third parties to embed GWT applications into our website and do some communication with them using simple iFrame postMessage. All these third party modules are going to use our SDK which is also GWT based. The problem arises that even though all the modules will be using the same codebase there is going to be a massive overheard in the amount of duplicate Javascript code (i.e. our common SDK code base which is quite large) being downloaded on the client's machine. This is highly redundant and problematic, not only due to the sheer size of duplicate code but, also due to the fact that subsequent updates of the SDK would require the modules to be recompiled which is going to create a DLL hell kind of scenario in the long run. What is the best way of doing this kind of thing? Is there a way where I can have some static GWT code (i.e. the SDK) and the dynamic GWT module refers to it (even if lies on a different domain) and it all work happily? The other part of the problem lies in providing robust scripting front end to the SDK. At first it appears to be trivial since Javascript itself is a scripting language. However, I do not know how to load and call a piece of pure Javascript code at runtime? I am willing to put restrictions on the target Javascript (i.e. having a function main and unique namespace or something). Furthermore the Javascript will come as a string from a database and not as a full URL. If its doable in Javascript how does one get this right in GWT i.e. forcing the compiler to emit a certain function in the generated Javascript? This I believe can be lesser of a problem by having a stub Javascript with all the right requirements which just loads up a GWT generated Javascript. Is any of this possible at all? I generally hate to be this verbose but I hope to find a quick solution to the problem as its holding up my progress. I'd highly appreciate any comments, suggestions and experiences.

  Read the article

• What are the Options for Storing Hierarchical Data in a Relational Database?

  - by orangepips

  Good Overviews One more Nested Intervals vs. Adjacency List comparison: the best comparison of Adjacency List, Materialized Path, Nested Set and Nested Interval I've found. Models for hierarchical data: slides with good explanations of tradeoffs and example usage Representing hierarchies in MySQL: very good overview of Nested Set in particular Hierarchical data in RDBMSs: most comprehensive and well organized set of links I've seen, but not much in the way on explanation Options Ones I am aware of and general features: Adjacency List: Columns: ID, ParentID Easy to implement. Cheap node moves, inserts, and deletes. Expensive to find level (can store as a computed column), ancestry & descendants (Bridge Hierarchy combined with level column can solve), path (Lineage Column can solve). Use Common Table Expressions in those databases that support them to traverse. Nested Set (a.k.a Modified Preorder Tree Traversal) First described by Joe Celko - covered in depth in his book Trees and Hierarchies in SQL for Smarties Columns: Left, Right Cheap level, ancestry, descendants Compared to Adjacency List, moves, inserts, deletes more expensive. Requires a specific sort order (e.g. created). So sorting all descendants in a different order requires additional work. Nested Intervals Combination of Nested Sets and Materialized Path where left/right columns are floating point decimals instead of integers and encode the path information. Bridge Table (a.k.a. Closure Table: some good ideas about how to use triggers for maintaining this approach) Columns: ancestor, descendant Stands apart from table it describes. Can include some nodes in more than one hierarchy. Cheap ancestry and descendants (albeit not in what order) For complete knowledge of a hierarchy needs to be combined with another option. Flat Table A modification of the Adjacency List that adds a Level and Rank (e.g. ordering) column to each record. Expensive move and delete Cheap ancestry and descendants Good Use: threaded discussion - forums / blog comments Lineage Column (a.k.a. Materialized Path, Path Enumeration) Column: lineage (e.g. /parent/child/grandchild/etc...) Limit to how deep the hierarchy can be. Descendants cheap (e.g. LEFT(lineage, #) = '/enumerated/path') Ancestry tricky (database specific queries) Database Specific Notes MySQL Use session variables for Adjacency List Oracle Use CONNECT BY to traverse Adjacency Lists PostgreSQL ltree datatype for Materialized Path SQL Server General summary 2008 offers HierarchyId data type appears to help with Lineage Column approach and expand the depth that can be represented.

  Read the article

• Using pointers, references, handles to generic datatypes, as generic and flexible as possible

  - by Patrick

  In my application I have lots of different data types, e.g. Car, Bicycle, Person, ... (they're actually other data types, but this is just for the example). Since I also have quite some 'generic' code in my application, and the application was originally written in C, pointers to Car, Bicycle, Person, ... are often passed as void-pointers to these generic modules, together with an identification of the type, like this: Car myCar; ShowNiceDialog ((void *)&myCar, DATATYPE_CAR); The 'ShowNiceDialog' method now uses meta-information (functions that map DATATYPE_CAR to interfaces to get the actual data out of Car) to get information of the car, based on the given data type. That way, the generic logic only has to be written once, and not every time again for every new data type. Of course, in C++ you could make this much easier by using a common root class, like this class RootClass { public: string getName() const = 0; }; class Car : public RootClass { ... }; void ShowNiceDialog (RootClass *root); The problem is that in some cases, we don't want to store the data type in a class, but in a totally different format to save memory. In some cases we have hundreds of millions of instances that we need to manage in the application, and we don't want to make a full class for every instance. Suppose we have a data type with 2 characteristics: A quantity (double, 8 bytes) A boolean (1 byte) Although we only need 9 bytes to store this information, putting it in a class means that we need at least 16 bytes (because of the padding), and with the v-pointer we possibly even need 24 bytes. For hundreds of millions of instances, every byte counts (I have a 64-bit variant of the application and in some cases it needs 6 GB of memory). The void-pointer approach has the advantage that we can almost encode anything in a void-pointer and decide how to use it if we want information from it (use it as a real pointer, as an index, ...), but at the cost of type-safety. Templated solutions don't help since the generic logic forms quite a big part of the application, and we don't want to templatize all this. Additionally, the data model can be extended at run time, which also means that templates won't help. Are there better (and type-safer) ways to handle this than a void-pointer? Any references to frameworks, whitepapers, research material regarding this?

  Read the article

• Need help accessing PHP DOM elements

  - by Michael Pasqualone

  Hey guys, I have the following HTML structure that I am trying to pull information from: // Product 1 <div class="productName"> <span id="product-name-1">Product Name 1</span> </div> <div class="productDetail"> <span class="warehouse">Warehouse 1, ACT</span> <span class="quantityInStock">25</span> </div> // Product 2 <div class="productName"> <span id="product-name-2">Product Name 2</span> </div> <div class="productDetail"> <span class="warehouse">Warehouse 2, ACT</span> <span class="quantityInStock">25</span> </div> … // Product X <div class="productName"> <span id="product-name-X">Product Name X</span> </div> <div class="productDetail"> <span class="warehouse">Warehouse X, ACT</span> <span class="quantityInStock">25</span> </div> I don't have control of the source html and as you'll see productName and it's accompanying productDetail are not contained within a common element. Now, I am using the following php code to try and parse the page. $html = new DOMDocument(); $html->loadHtmlFile('product_test.html'); $xPath = new DOMXPath($html); $domQuery = '//div[@class="productName"]|//div[@class="productDetail"]'; $entries = $xPath->query($domQuery); foreach ($entries as $entry) { echo "Detail: " . $entry->nodeValue) . "<br />\n"; } Which prints the following: Detail: Product Name 1 Detail: Warehouse 1, ACT Detail: 25 Detail: Product Name 2 Detail: Warehouse 2, ACT Detail: 25 Detail: Product Name X Detail: Warehouse X, ACT Detail: 25 Now, this is close to what I want. But I need to do some processing on each Product, Warehouse and Quantity stock and can't figure out how to parse it out into separate product groups. The final output I am after is something like: Product 1: Name: Product Name 1 Warehouse: Warehouse 1, ACT Stock: 25 Product 2: Name: Product Name 2 Warehouse: Warehouse 2, ACT Stock: 25 I can't just figure it out, and I can't wrap my head around this DOM stuff as the elements don't quite work the same as a standard array. If anyone can assist, or point me in the right direction I will be ever appreciative.

  Read the article

• How to learn proper C++?

  - by Chris

  While reading a long series of really, really interesting threads, I've come to a realization: I don't think I really know C++. I know C, I know classes, I know inheritance, I know templates (& the STL) and I know exceptions. Not C++. To clarify, I've been writing "C++" for more than 5 years now. I know C, and I know that C and C++ share a common subset. What I've begun to realize, though, is that more times than not, I wind up treating C++ something vaguely like "C with classes," although I do practice RAII. I've never used Boost, and have only read up on TR1 and C++0x - I haven't used any of these features in practice. I don't use namespaces. I see a list of #defines, and I think - "Gracious, that's horrible! Very un-C++-like," only to go and mindlessly write class wrappers for the sake of it, and I wind up with large numbers (maybe a few per class) of static methods, and for some reason, that just doesn't seem right lately. The professional in me yells "just get the job done," the academic yells "you should write proper C++ when writing C++" and I feel like the point of balance is somewhere in between. I'd like to note that I don't want to program "pure" C++ just for the sake of it. I know several languages. I have a good feel for what "Pythonic" is. I know what clean and clear PHP is. Good C code I can read and write better than English. The issue is that I learned C by example, and picked up C++ as a "series of modifications" to C. And a lot of my early C++ work was creating class wrappers for C libraries. I feel like my own personal C-heavy background while learning C++ has sort of... clouded my acceptance of C++ in it's own right, as it's own language. Do the weathered C++ lags here have any advice for me? Good examples of clean, sharp C++ to learn from? What habits of C does my inner-C++ really need to break from? My goal here is not to go forth and trumpet "good" C++ paradigm from rooftops for the sake of it. C and C++ are two different languages, and I want to start treating them that way. How? Where to start? Thanks in advance! Cheers, -Chris

  Read the article

• approximating log10[x^k0 + k1]

  - by Yale Zhang

  Greetings. I'm trying to approximate the function Log10[x^k0 + k1], where .21 < k0 < 21, 0 < k1 < ~2000, and x is integer < 2^14. k0 & k1 are constant. For practical purposes, you can assume k0 = 2.12, k1 = 2660. The desired accuracy is 5*10^-4 relative error. This function is virtually identical to Log[x], except near 0, where it differs a lot. I already have came up with a SIMD implementation that is ~1.15x faster than a simple lookup table, but would like to improve it if possible, which I think is very hard due to lack of efficient instructions. My SIMD implementation uses 16bit fixed point arithmetic to evaluate a 3rd degree polynomial (I use least squares fit). The polynomial uses different coefficients for different input ranges. There are 8 ranges, and range i spans (64)2^i to (64)2^(i + 1). The rational behind this is the derivatives of Log[x] drop rapidly with x, meaning a polynomial will fit it more accurately since polynomials are an exact fit for functions that have a derivative of 0 beyond a certain order. SIMD table lookups are done very efficiently with a single _mm_shuffle_epi8(). I use SSE's float to int conversion to get the exponent and significand used for the fixed point approximation. I also software pipelined the loop to get ~1.25x speedup, so further code optimizations are probably unlikely. What I'm asking is if there's a more efficient approximation at a higher level? For example: Can this function be decomposed into functions with a limited domain like log2((2^x) * significand) = x + log2(significand) hence eliminating the need to deal with different ranges (table lookups). The main problem I think is adding the k1 term kills all those nice log properties that we know and love, making it not possible. Or is it? Iterative method? don't think so because the Newton method for log[x] is already a complicated expression Exploiting locality of neighboring pixels? - if the range of the 8 inputs fall in the same approximation range, then I can look up a single coefficient, instead of looking up separate coefficients for each element. Thus, I can use this as a fast common case, and use a slower, general code path when it isn't. But for my data, the range needs to be ~2000 before this property hold 70% of the time, which doesn't seem to make this method competitive. Please, give me some opinion, especially if you're an applied mathematician, even if you say it can't be done. Thanks.

  Read the article

• How to remove the explicit dependencies to other projects' libraries in Eclipse launch configuration

  - by euluis

  In Eclipse it is possible to create launch configurations in a project, specifying the runtime dependencies from another project. A problem I found was that if you have a multiple project workspace, being possible that each project has its own libraries, it is easy to add explicit dependencies in a secondary project to libraries that are of another project and therefore subject to change. An example of this problem follows: proj1 +-- src +-- lib +-- jar1-v1.0.jar +-- jar2-v1.0.jar proj2 +-- src +-- proj2-tests.launch I don't have a dependency from the code in proj2/src to the libraries in proj1/lib. Nevertheless, I do have a dependency from proj2/src to proj1/src, although since there is an internal dependency in the code in proj1/src to its libraries jar1-v1.0.jar and jar2.v1.0.jar, I have to add a dependency in proj2-tests.launch to the libraries in proj1/lib. This translates to the following ugly lines in proj2-tests.launch: <listEntry value="<?xml version="1.0" encoding="UTF-8" standalone="no"?> <runtimeClasspathEntry path="3" projectName="proj1" type="1"/> "/> <listEntry value="<?xml version="1.0" encoding="UTF-8" standalone="no"?> <runtimeClasspathEntry internalArchive="/proj1/lib/jar1-v1.0.jar" path="3" type="2"/> "/> <listEntry value="<?xml version="1.0" encoding="UTF-8" standalone="no"?> <runtimeClasspathEntry internalArchive="/proj1/lib/jar2-v1.0.jar" path="3" type="2"/> "/> This wouldn't be a big problem if there wasn't the need from time to time to evolve the software, upgrade the libraries and etc. Consider the common need to upgrade the libraries jar1-v1.0.jar and jar2-v1.0.jar to their versions v1.1. Consider that you have about 10 projects in one workspace, having about 5 libraries each and about 4 launch configurations. You get a maintenance overhead in doing a simple upgrade of a library, which normally must imply changes in files for which there wasn't the need for. Or maybe I'm doing something wrong... What I would like to state is proj2 depends on proj1 and on its libraries and having this translated to simply that in the *.launch files. Is that possible?

  Read the article

• Why I get java.net.SocketException: Connection reset

  - by Jammy

  I need sent some requests to server side and get reponse, sometimes when I call specific method to run the flollowing common code, I get one error in line(addToCookieJar(connection);), any idea how this get happened? URL url = new URL(providerURL); HttpURLConnection connection = (HttpURLConnection)url.openConnection(); connection.setRequestMethod("POST"); connection.setDoInput(true); connection.setDoOutput(true); connection.setUseCaches(false); connection.setRequestProperty("Content-Type", "application/octet-stream"); // We understand gzip encoding connection.addRequestProperty("Accept-Encoding", "gzip"); if (cookie != null && cookieHandler != null) { connection.setRequestProperty("Cookie", cookie); } if (cookieHandler == null) { addFromCookieJar(connection); } // Send the request ObjectOutputStream oos = new ObjectOutputStream(connection.getOutputStream()); oos.writeObject(remote.getName()); oos.writeObject(m.getName()); // method name oos.writeObject(m.getParameterTypes()); // formal parameters oos.writeObject(args); // actual parameters oos.flush(); oos.close(); if (cookieHandler == null) { cookieJar.put(new URI(providerURL), connection.getHeaderFields()); } Exception: java.lang.reflect.UndeclaredThrowableException at $Proxy0.updateDocument(Unknown Source) at com.agst.ui.gantt.GanttPanel.doUpdateDocument(GanttPanel.java:1931) at com.agst.ui.gantt.GanttPanel.save(GanttPanel.java:1419) at com.agst.ui.gantt.GanttPanel$4.run(GanttPanel.java:1673) at java.lang.Thread.run(Unknown Source) Caused by: java.net.SocketException: Connection reset at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection$6.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at sun.net.www.protocol.http.HttpURLConnection.getChainedException(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) at com.agst.rmi.RemoteCallHandler.call(RemoteCallHandler.java:196) at com.agst.rmi.RemoteCallHandler.invoke(RemoteCallHandler.java:142) ... 5 more Caused by: java.net.SocketException: Connection reset at java.net.SocketInputStream.read(Unknown Source) at java.io.BufferedInputStream.fill(Unknown Source) at java.io.BufferedInputStream.read1(Unknown Source) at java.io.BufferedInputStream.read(Unknown Source) at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source) at sun.net.www.http.HttpClient.parseHTTP(Unknown Source) at sun.net.www.http.HttpClient.parseHTTP(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getHeaderFields(Unknown Source) at com.agst.rmi.RemoteCallHandler.addToCookieJar(RemoteCallHandler.java:529) at com.agst.rmi.RemoteCallHandler.call(RemoteCallHandler.java:192) ... 6 more

  Read the article

• Basic shared memory program in C

  - by nicopuri

  Hi, I want to make a basic chat application in C using Shared memory. I am working in Linux. The application consist in writing the client and the server can read, and if the server write the client can read the message. I tried to do this, but I can't achieve the communication between client and server. The code is the following: Server.c int main(int argc, char **argv) { char *msg; static char buf[SIZE]; int n; msg = getmem(); memset(msg, 0, SIZE); initmutex(); while ( true ) { if( (n = read(0, buf, sizeof buf)) 0 ) { enter(); sprintf(msg, "%.*s", n, buf); printf("Servidor escribe: %s", msg); leave(); }else{ enter(); if ( strcmp(buf, msg) ) { printf("Servidor lee: %s", msg); strcpy(buf, msg); } leave(); sleep(1); } } return 0; } Client.c int main(int argc, char **argv) { char *msg; static char buf[SIZE-1]; int n; msg = getmem(); initmutex(); while(true) { if ( (n = read(0, buf, sizeof buf)) 0 ) { enter(); sprintf(msg, "%.*s", n, buf); printf("Cliente escribe: %s", msg); leave(); }else{ enter(); if ( strcmp(buf, msg) ) { printf("Cliente lee: %s", msg); strcpy(buf, msg); } leave(); sleep(1); } } printf("Cliente termina\n"); return 0; } The shared memory module is the folowing: #include "common.h" void fatal(char *s) { perror(s); exit(1); } char * getmem(void) { int fd; char *mem; if ( (fd = shm_open("/message", O_RDWR|O_CREAT, 0666)) == -1 ) fatal("sh_open"); ftruncate(fd, SIZE); if ( !(mem = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) ) fatal("mmap"); close(fd); return mem; } static sem_t *sd; void initmutex(void) { if ( !(sd = sem_open("/mutex", O_RDWR|O_CREAT, 0666, 1)) ) fatal("sem_open"); } void enter(void) { sem_wait(sd); } void leave(void) { sem_post(sd); }

  Read the article

• LinearLayout as custom button, OnClickListener never called

  - by ohra

  I've been using the common Android Button with both icon (drawableTop) and text. It works really poorly if you want to have a non-standard size button, so I decided to make a custom button with a LinearLayout having the following layout: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" style="@style/ButtonHoloDark" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center" android:clickable="true" android:focusable="true" android:orientation="vertical" > <ImageView android:id="@+id/buttonIcon" android:layout_width="fill_parent" android:layout_height="wrap_content" android:duplicateParentState="true" /> <TextView android:id="@+id/buttonText" android:layout_width="fill_parent" android:layout_height="wrap_content" android:duplicateParentState="true" android:gravity="center" android:textColor="@color/white" /> </LinearLayout> The layout is used by a custom class: public class CustomIconButton extends LinearLayout { public CustomIconButton(Context context, AttributeSet attrs) { super(context, attrs); setAttributes(context, attrs); LayoutInflater.from(context).inflate(R.layout.custom_icon_button, this, true); } ... But when I set an OnClickListener on my button in its parent layout it never gets called. I can only receive clicks if a set the listener to the ImageView and/or TextView. This leads to two possible effects when the button is clicked: The click is inside the ImageView or the TextView. The click is registered ok, but the buttons state drawable doesn't change i.e. it doesn't appear depressed. The click is inside the "empty area" of the button. The click is not registered, but the state drawable works ok. Neither of these is feasible. I've played around with the following attributes on the LinearLayout or its children, but none really seem to have any effect whether true or false: duplicateParentState clickable focusable There doesn't seem to be any reasonable way to get the LinearLayout parent receive clicks instead of its children. I've seen some possible solutions overriding dispatchTouchEvent or onInterceptTouchEvent on the custom component itself, but that really seems like a big mess if I have to start analyzing touch events to identify proper clicks. So OnClickListener on a LinearLayout with children = no go?

  Read the article

• Foreign key pointing to different tables

  - by Álvaro G. Vicario

  I'm implementing a table per subclass design I discussed in a previous question. It's a product database where products can have very different attributes depending on their type, but attributes are fixed for each type and types are not manageable at all. I have a master table that holds common attributes: product_type ============ product_type_id INT product_type_name VARCHAR E.g.: 1 'Magazine' 2 'Web site' product ======= product_id INT product_name VARCHAR product_type_id INT -> Foreign key to product_type.product_type_id valid_since DATETIME valid_to DATETIME E.g. 1 'Foo Magazine' 1 '1998-12-01' NULL 2 'Bar Weekly Review' 1 '2005-01-01' NULL 3 'E-commerce App' 2 '2009-10-15' NULL 4 'CMS' 2 '2010-02-01' NULL ... and one subtable for each product type: item_magazine ============= item_magazine_id INT title VARCHAR product_id INT -> Foreign key to product.product_id issue_number INT pages INT copies INT close_date DATETIME release_date DATETIME E.g. 1 'Foo Magazine Regular Issue' 1 89 52 150000 '2010-06-25' '2010-06-31' 2 'Foo Magazine Summer Special' 1 90 60 175000 '2010-07-25' '2010-07-31' 3 'Bar Weekly Review Regular Issue' 2 12 16 20000 '2010-06-01' '2010-06-02' item_web_site ============= item_web_site_id INT name VARCHAR product_id INT -> Foreign key to product.product_id bandwidth INT hits INT date_from DATETIME date_to DATETIME E.g. 1 'The Carpet Store' 3 10 90000 '2010-06-01' NULL 2 'Penauts R Us' 3 20 180000 '2010-08-01' NULL 3 'Springfield Cattle Fair' 4 15 150000 '2010-05-01' '2010-10-31' Now I want to add some fees that relate to one specific item. Since there are very little subtypes, it's feasible to do this: fee === fee_id INT fee_description VARCHAR item_magazine_id INT -> Foreign key to item_magazine.item_magazine_id item_web_site_id INT -> Foreign key to item_web_site.item_web_site_id net_price DECIMAL E.g.: 1 'Front cover' 2 NULL 1999.99 2 'Half page' 2 NULL 500.00 3 'Square banner' NULL 3 790.50 4 'Animation' NULL 3 2000.00 I have tight foreign keys to handle cascaded editions and I presume I can add a constraint so only one of the IDs is NOT NULL. However, my intuition suggests that it would be cleaner to get rid of the item_WHATEVER_id columns and keep a separate table: fee_to_item =========== fee_id INT -> Foreign key to fee.fee_id product_id INT -> Foreign key to product.product_id item_id INT -> ??? But I can't figure out how to create foreign keys on item_id since the source table varies depending on product_id. Should I stick to my original idea?

  Read the article

< Previous Page | 320 321 322 323 324 325 326 327 328 329 330 331  | Next Page >