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  • Tool that auto-generate a code for accesing a xml-file

    - by alex
    My application have a configuration xml-file. That file contains more than 50 program settings. At the present time I read and save each program setting separately. I guess It is not effi?iently for such tasks. I need something that can auto-generate a code for load and save my program settings using predefined xml-schema. I found a dataset in Add New Item dialog. Unfortunately, i cannot add new code to dataset1 such as events in set-accessors of properties because of this // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. Maybe, there is a tool that allows a user to generate a wrapper for accesing a xml-file ? Such as DataSet1, but with availability to add events.

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  • Why represent shopping carts and order invoices differently in a domain model?

    - by Todd
    I've built some shopping cart systems in the past, but I always designed them such that the final order invoice is just a shopping cart that has been marked as "purchased". All the logic for adding/removing/changing items in a cart is also the logic for the order. All data is stored in the same tables in the database. But it seems this is not the proper way to design an e-commerce site.. Can someone explain the benefit of separating the shopping cart from invoices in the domain model? It seems to me this would lead to a lot of duplicated code, an extra set of tables in the database, and make it harder to maintain in the event the system need to start accommodating more complicated orders (like specifying selected options for an item which may or may not change the price/availability/shipping time of the order). I'm assuming I just haven't seen the light, as every book and other example I see seems to separate these two seemingly similar concerns -- but I can't find any explanation as to the benefit of doing such! It's also the case in the systems that I design that changes are often made after the initial order is confirmed. It's not uncommon for items to be removed, replaced, or added afterwards (but prior to fulfillment).

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  • Comparing objects and inheritance

    - by ereOn
    Hi, In my program I have the following class hierarchy: class Base // Base is an abstract class { }; class A : public Base { }; class B : public Base { }; I would like to do the following: foo(const Base& one, const Base& two) { if (one == two) { // Do something } else { // Do something else } } I have issues regarding the operator==() here. Of course comparing an instance A and an instance of B makes no sense but comparing two instances of Base should be possible. (You can't compare a Dog and a Cat however you can compare two Animals) I would like the following results: A == B = false A == A = true or false, depending on the effective value of the two instances B == B = true or false, depending on the effective value of the two instances My question is: is this a good design/idea ? Is this even possible ? What functions should I write/overload ? My apologies if the question is obviously stupid or easy, I have some serious fever right now and my thinking abilities are somewhat limited :/ Thank you.

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  • Performing centralized authorization for multiple applications

    - by Vaibhav
    Here's a question that I have been wrestling with for a while. We have a situation wherein we have a number of applications that we have created. These have grown organically over a period of time. All of these applications have permissions code built into them that controls access to various parts of the application depending on whether the currently logged in user has the necessary permissions or not. Alongside these applications is a utility application which allows an administrator to map users to permissions for all applications - the way it works is that every application has code which reads this external database of the said utility application to check if the currently logged in user has the necessary permission or not. Now, the question is this. Should the user-permissions mapping information reside in and be owned by the applications themselves, or is it okay to have this information reside within an external entity/DB (as in this case the utility application's database). Part of me thinks that application permissions are very specific to the application context itself, so shouldn't be separated from the application itself. But I am not sure. Any comments?

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  • Protocol specification in XML

    - by Mathijs
    Is there a way to specify a packet-based protocol in XML, so (de)serialization can happen automatically? The context is as follows. I have a device that communicates through a serial port. It sends and receives a byte stream consisting of 'packets'. A packet is a collection of elementary data types and (sometimes) other packets. Some elements of packets are conditional; their inclusion depends on earlier elements. I have a C# application that communicates with this device. Naturally, I don't want to work on a byte-level throughout my application; I want to separate the protocol from my application code. Therefore I need to translate the byte stream to structures (classes). Currently I have implemented the protocol in C# by defining a class for each packet. These classes define the order and type of elements for each packet. Making class members conditional is difficult, so protocol information ends up in functions. I imagine XML that looks like this (note that my experience designing XML is limited): <packet> <field name="Author" type="int32" /> <field name="Nickname" type="bytes" size="4"> <condition type="range"> <field>Author</field> <min>3</min> <max>6</min> </condition> </field> </packet> .NET has something called a 'binary serializer', but I don't think that's what I'm looking for. Is there a way to separate protocol and code, even if packets 'include' other packets and have conditional elements?

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  • using partials in view helpers

    - by takeshin
    Creating custom Zend View helpers I often end up with something like: // logic here if ($condition) { $output = <<<EOS... } else { $output = <<<EOS... } or using switch. Then to eliminate this, I create setPartial(), getPartial() and htmlize() for using external .phtml's. This is not the best solution, because partials do not support doctype changing. Is there any better solution, than creating abstract class handling this common case? Are there any ready Zend solutions for this case? Separate view helper for each case? And where to put common code?

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  • Magic Method __set() on a Instantiated Object

    - by streetparade
    Ok i have a problem, sorry if i cant explaint it clear but the code speaks for its self. i have a class which generates objects from a given class name; Say we say the class is Modules: public function name($name) { $this->includeModule($name); try { $module = new ReflectionClass($name); $instance = $module->isInstantiable() ? $module->newInstance() : "Err"; $this->addDelegate($instance); } catch(Exception $e) { Modules::Name("Logger")->log($e->getMessage()); } return $this; } The AddDelegate Method: protected function addDelegate($delegate) { $this->aDelegates[] = $delegate; } The __call Method public function __call($methodName, $parameters) { $delegated = false; foreach ($this->aDelegates as $delegate) { if(class_exists(get_class($delegate))) { if(method_exists($delegate,$methodName)) { $method = new ReflectionMethod(get_class($delegate), $methodName); $function = array($delegate, $methodName); return call_user_func_array($function, $parameters); } } } The __get Method public function __get($property) { foreach($this->aDelegates as $delegate) { if ($delegate->$property !== false) { return $delegate->$property; } } } All this works fine expect the function __set public function __set($property,$value) { //print_r($this->aDelegates); foreach($this->aDelegates as $k=>$delegate) { //print_r($k); //print_r($delegate); if (property_exists($delegate, $property)) { $delegate->$property = $value; } } //$this->addDelegate($delegate); print_r($this->aDelegates); } class tester { public function __set($name,$value) { self::$module->name(self::$name)->__set($name,$value); } } Module::test("logger")->log("test"); // this logs, it works echo Module::test("logger")->path; //prints /home/bla/test/ this is also correct But i cant set any value to class log like this Module::tester("logger")->path ="/home/bla/test/log/"; The path property of class logger is public so its not a problem of protected or private property access. How can i solve this issue? I hope i could explain my problem clear.

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  • highlite text parts with jquery, best practice

    - by helle
    Hey guys, i have a list of items containig names. then i have a eventlistener, which ckecks for keypress event. if the user types i.g. an A all names starting with an A should be viewed with the A bold. so all starting As should be bold. what is the best way using jquery to highlite only a part of a string? thanks for your help

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  • How to avoid nested functions when using AJAX?

    - by Fletcher Moore
    Sequential Asynchronous calls are gross. Is there a more readable solution? The problem is this is hard to follow: ajaxOne(function() { // do something ajaxTwo(function() { // do something ajaxThree() }); }); where the anonymous functions are callbacks that are called on server response. I'm using a third party API to make the AJAX calls, so I need a generic solution.

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  • What is a mantainable way of saving "star rating" in a database?

    - by Montecristo
    I'll use the jQuery plugin for presenting the user with a nice interface The request is to display 5 stars, up to a total score of 10 (2 points per star). By now I thought about using 7/10 as a format for that value, but what if at some point in the future I'll receive a request like We would like to give users more choice, let's increase the total score to 20 (so that each star contributes with a maximum of 4 points) I'll end up with a table with mixed values for the "star rating" column: some will be like 7/10 while others will be like 14/20. Is it ok for you to have this difference in the database and deal with it in the logic layer to have it consistent? Or is preferred another way so that querying the table will not result in inconsistent results outside the application? Maybe floating point values could help me, is it better to store that value as a number less than or equal to one? So in each of the two examples the resulting value stored in the database would be 0,7, as a number, not a varchar, which can be queried also outside the application. What do you think?

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  • Arguments to convince to switch from CVS to SVN

    - by ereOn
    Hi, The UNIX department of my company currently uses CVS as source-version control system. They use it in a very strange way: different repositories for development/testing/production code (for the same project), no one tags anything, weird directory architecture, and so on. The system has been set for ages but now, I have an opportunity to organize a meeting where I have to suggest changes. I'd like to make them change from CVS to SVN (Mercurial or Git might be even better, however I can't really recommand using a system I don't know well, and switching to SVN will already be a great step forward). I don't have much experience with CVS so I can't compare them efficiently: I just know it doesn't support atomic operations and that it is deprecated. What killer arguments would you use to convince my collegues to do the switch ? Thank you very much.

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  • When is C++ covariance the best solution?

    - by Neil Butterworth
    This question was asked here a few hours ago and made me realise that I have never actually used covariant return types in my own code. For those not sure what covariance is, it's allowing the return type of (typically) virtual functions to differ provided the types are part of the same inheritance hierarchy. For example: struct A { virtual ~A(); virtual A * f(); ... }; struct B : public A { virtual B * f(); ... }; The different return types of the two f() functions are said to be covariant. Older versions of C++ required the return types to be the same, so B would have to look like: struct B : public A { virtual A * f(); ... }; So, my question: Does anyone have a real-world example where covariant return types of virtual functions are required, or produce a superior solution to simply returning a base pointer or reference?

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  • using ref to view error

    - by Avram
    Hello. I working now on firm that using ref in every function. The reason, is to catch errors. There example : //return true if the read is success //otherwise writing to the error ,the problem bool ReadFile(ref string error) Question: How do you catching errors? Using ref,exceptions or other way?

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  • C++ error message output format

    - by sub
    If I want to trigger an error in my interpreter I call this function: Error( ErrorType type, ErrorSeverity severity, const char* msg, int line ); However, with that I can only output Name error: Undefined variable in line 1 instead of Name error: Undefined variable 'someVariableName' in line 1 I'm working entirely with strings (except for the error messages as they all are constant at the moment), so sprintf won't work. What is the best way to create an efficient error function that can output a constant message combined with a string that describes which object, e.g.: a non-existing variable, triggered the error?

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  • Are there any inherent benefits or drawbacks to choosing Google Code vs. SourceForge vs. Codeplex?

    - by kdmurray
    I've got a couple of different projects that I'd like to post up as open source. I've been trying to decide which of the three big open-source project hosting sites makes the most sense, or if I should just host it myself. Are there any inherent drawbacks or benefits to these three? Is there a "best" place to host a project? Do different sites make more sense for different kinds of projects?

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  • Which options do I have for Java process communication?

    - by Dmitriy Matveev
    We have a place in a code of such form: void processParam(Object param) { wrapperForComplexNativeObject result = jniCallWhichMayCrash(param); processResult(result); } processParam - method which is called with many different arguments. jniCallWhichMayCrash - a native method which is intended to do some complex processing of it's parameter and to create some complex object. It can crash in some cases. wrapperForComplexNativeObject - wrapper type generated by SWIG processResult - a method written in pure Java which processes it's parameter by creation of several kinds (by the kinds I'm not meaning classes, maybe some like hierarchies) of objects: 1 - Some non-unique objects which are referencing each other (from the same hierarchy), these objects can have duplicates created from the invocations of processParam() method with different parameter values. Since it's costly to keep all the duplicates it's necessary to cache them. 2 - Some unique objects which are referencing each other (from the same hierarchy) and some of the objects of 1st kind. After processParam is executed for each of the arguments from some set the data created in processResult will be processed together. The problem is in fact that jniCallWhichMayCrash method may crash the entire JVM and this will be very bad. The reason of crash may be such that it can happen for one argument value and not for the other. We've decided that it's better to ignore crashes inside of JVM and just skip some chunks of data when such crashes occur. In order to do this we should run processParam function inside of separate process and pass the result somehow (HOW? HOW?! This is a question) to the main process and in case of any crashes we will only lose some part of data (It's ok) without lose of everything else. So for now the main problem is implementation of transport between different processes. Which options do I have? I can think about serialization and transmitting of binary data by the streams, but serialization may be not very fast due to object complexity. Maybe I have some other options of implementing this?

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  • C++ Iterator Pipelining Designs

    - by Kirakun
    Suppose we want to apply a series of transformations, int f1(int), int f2(int), int f3(int), to a list of objects. A naive way would be SourceContainer source; TempContainer1 temp1; transform(source.begin(), source.end(), back_inserter(temp1), f1); TempContainer2 temp2; transform(temp1.begin(), temp1.end(), back_inserter(temp2), f2); TargetContainer target; transform(temp2.begin(), temp2.end(), back_inserter(target), f3); This first solution is not optimal because of the extra space requirement with temp1 and temp2. So, let's get smarter with this: int f123(int n) { return f3(f2(f1(n))); } ... SourceContainer source; TargetContainer target; transform(source.begin(), source.end(), back_inserter(target), f123); This second solution is much better because not only the code is simpler but more importantly there is less space requirement without the intermediate calculations. However, the composition f123 must be determined at compile time and thus is fixed at run time. How would I try to do this efficiently if the composition is to be determined at run time? For example, if this code was in a RPC service and the actual composition--which can be any permutation of f1, f2, and f3--is based on arguments from the RPC call.

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  • Is this multi line if statement too complex?

    - by AndHeCodedIt
    I am validating input on a form and attempting to prompt the user of improper input(s) based on the combination of controls used. For example, I have 2 combo boxes and 3 text boxes. The 2 combo boxes must always have a value other than the first (default) value, but one of three, or two of three, or all text boxes can be filled to make the form valid. In one such scenario I have a 6 line if statement to try to make the test easily readable: if ((!String.Equals(ComboBoxA.SelectedValue.ToString(), DEFAULT_COMBO_A_CHOICE.ToString()) && !String.IsNullOrEmpty(TextBoxA.Text) && !String.Equals(ComboBoxB.SelectedValue.ToString(), DEFAULT_COMBO_B_CHOICE.ToString())) || (!String.IsNullOrEmpty(TextBoxB.Text) || !String.IsNullOrEmpty(TextBoxC.Text))) { //Do Some Validation } I have 2 questions: Should this type of if statement be avoided at all cost? Would it be better to enclose this test in another method? (This would be a good choice as this validation will happen in more than one scenario) Thanks for your input(s)!

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  • Alternative to jQuery .data()?

    - by thebossman
    I'm a big fan of jQuery's .data() method, but I can't always use it. Often times I am rendering html templates that I pass via AJAX and I need to attach metadata to each of the elements in the template. For example: <ul> {% for item in itemlist %} <li metadata="{{ item.metadata }}">{{ item.name }}</li> {% endfor %} </ul> I know attaching attributes to store data is bad practice (and it might not even work in older versions of IE). What is the best practice? Is there a good alternative to this method?

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