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  • Java application design question

    - by ring bearer
    I have a hobby project, which is basically to maintain 'todo' tasks in the way I like. One task can be described as: public class TodoItem { private String subject; private Date dueBy; private Date startBy; private Priority priority; private String category; private Status status; private String notes; } As you can imagine I would have 1000s of todo items at a given time. What is the best strategy to store a todo item? (currently on an XML file) such that all the items are loaded quickly up on app start up(the application shows kind of a dashboard of all the items at start up)? What is the best way to design its back-end so that it can be ported to Android/or a J2ME based phone? Currently this is done using Java Swing. What should I concentrate on so that it works efficiently on a device where memory is limited? The application throws open a form to enter new todo task. For now, I would like to save the newly added task to my-todos.xml once the user presses "save" button. What are the common ways to append such a change to an existing XML file?(note that I don't want to read the whole file again and then persist)

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  • How do I launch background jobs w/ paramiko?

    - by sophacles
    Here is my scenario: I am trying to automate some tasks using Paramiko. The tasks need to be started in this order (using the notation (host, task)): (A, 1), (B, 2), (C, 2), (A,3), (B,3) -- essentially starting servers and clients for some testing in the correct order. Further, because in the tests networking may get mucked up, and because I need some of the output from the tests, I would like to just redirect output to a file. In similar scenarios the common response is to use 'screen -m -d' or to use 'nohup'. However with paramiko's exec_cmd, nohup doesn't actually exit. Using: bash -c -l nohup test_cmd & doesnt work either, exec_cmd still blocks to process end. In the screen case, output redirection doesn't work very well, (actually, doesnt work at all the best I can figure out). So, after all that explanation, my question is: is there an easy elegant way to detach processes and capture output in such a way as to end paramiko's exec_cmd blocking? Update The dtach command works nicely for this!

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  • Email function using templates. Includes via ob_start and global vars

    - by Geo
    I have a simple Email() class. It's used to send out emails from my website. <? Email::send($to, $subj, $msg, $options); ?> I also have a bunch of email templates written in plain HTML pierced with a few PHP variables. E.g. /inc/email/templates/account_created.php: <p>Dear <?=$name?>,</p> <p>Thank you for creating an account at <?=$SITE_NAME?>. To login use the link below:</p> <p><a href="https://<?=$SITE_URL?>/account" target="_blank"><?=$SITE_NAME?>/account</a></p> In order to have the PHP vars rendered I had to include the template into my function. But since include does not return the contents but rather just sends it directly to the output, I had to wrap it with the buffer functions: <? abstract class Email { public static function send($to, $subj, $msg, $options = array()) { /* ... */ ob_start(); include '/inc/email/templates/account_created.php'; $msg = ob_get_clean(); /* ... */ } } After that I realized that the PHP vars are not rendered as they are being inside of the function scope, so I had to globalize the variables inside of the template: <? global $SITE_NAME, $SITE_URL, $name; ?> <p>Dear <?=$name?>,</p> ... So the question is whether there is a more elegant solution to this? Mainly I am concerned about my workarounds using ob_start() and global. For some reason that seems to me odd. Or this is pretty much the common practice?

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  • is there a Universal Model for languages?

    - by Smandoli
    Many programming languages share generic and even fairly universal features. For example, if you compared Java, VB6, .NET, PHP, Python, then you would find common functions such as control structures, numeric and string manipulation, etc. What has been done to define these features at a meta-language (or language-agnostic) level? UML offers a descriptive reference of software in every aspect, but the real-world focus seems to be data processes. Is UML relevant? I'm not asking "Why we don't have a single language that replaces the current plethora." We need many different tools (at least in this eon). I'm not asking that all languages fit a template -- assembly vs. compiled languages are different enough to make that unfeasible (and some folks call HTML a language, though I wouldn't). Any attempt would start with a properly narrow scope. In line with this, I wouldn't expect the model to cover even a small selection with full validity. I would expect however that such a model could be used to transpose from one language to another (with limited goals -- think jist translation).

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  • Creating content for rails-based applications

    - by Matthias Hryniszak
    Hi, I'm facing a problem of cleaning up my application in Ruby on Rails. What I have is a pretty standard 3-panel, header and footer layout where different parts of the screen contain different functionality. By that I mean for example that the header contains (among others) a select that allows one to select parts of the application and a context-dependent menu. The main content area contains obviously the most interactive stuff whereas side panels contain quick-links with stuff like shopping-cart preview, list of potentially attractive products for the customer, a selector to narrow down the list of options... I was wondering how do I go about simplifying the design. Right now I have the stuff that provides data for the "common" stuff (as opposed to direct content that's placed in the center) called from all the actions (with a filter) but that doesn't feel right for me. I've read that "components" are also not the way to go for obvious performance reasons. Is there something that's more like component-oriented (other frameworks do have that kind of stuff - Grails: <ui:include ../>, ASP.NET MVC: <% Html.RenderAction() %>)? Best regards, Matthias.

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  • Create a strongly typed view which inherites a class which is concrete

    - by Ashwani K
    Hello All: I am having one class called BaseClass which contains some logic applicable to whole web site. In order to create a strongly typed view we need to inherit the page from System.Web.Mvc.ViewPage generic class. But In our case I have to Inherit the BaseClass from System.Web.Mvc.ViewPage to apply some common settings, but the BaseClass should be inherited from System.Web.Mvc.ViewPage< generic version. But I cannot inherit the BaseClass from System.Web.Mvc.ViewPage< as it will change other class also. So I created one more class of type BaseClass< inheriting it from System.Web.Mvc.ViewPage< and copied the whole code of BaseClass in BaseClass<. But the code in BaseClass is controlled by other team so it will be changed frequently so my BaseClass< should be in sync with BaseClass. Please help me in eliminating the code duplication or any other approach to make strongly typed View. Thanks Ashwani

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  • JSF how to temporary disable validators to save draft

    - by Swiety
    I have a pretty complex form with lots of inputs and validators. For the user it takes pretty long time (even over an hour) to complete that, so they would like to be able to save the draft data, even if it violates rules like mandatory fields being not typed in. I believe this problem is common to many web applications, but can't find any well recognised pattern how this should be implemented. Can you please advise how to achieve that? For now I can see the following options: use of immediate=true on "Save draft" button doesn't work, as the UI data would not be stored on the bean, so I wouldn't be able to access it. Technically I could find the data in UI component tree, but traversing that doesn't seem to be a good idea. remove all the fields validation from the page and validate the data programmaticaly in the action listener defined for the form. Again, not a good idea, form is really complex, there are plenty of fields so validation implemented this way would be very messy. implement my own validators, that would be controlled by some request attribute, which would be set for standard form submission (with full validation expected) and would be unset for "save as draft" submission (when validation should be skipped). Again, not a good solution, I would need to provide my own wrappers for all validators I am using. But as you see no one is really reasonable. Is there really no simple solution to the problem?

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  • Where do I put jar files in Tomcat 6?

    - by Simon
    I am having trouble getting my JSP page to load a Java class which is in a jar file. The message I get appears to indicate a class not found exception: Jan 6, 2011 12:21:45 PM org.apache.catalina.core.StandardWrapperValve invoke SEVERE: Servlet.service() for servlet jsp threw exception org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: 72 in the jsp file: /xmlloader.jsp FactArray cannot be resolved to a type 69: sourceType = "1"; 70: } 71: 72: FactArray fa = new FactArray(); 73: Fact f; 74: 75: /***********************/ The Type FactArray is one of my classes in a package com.mypackage.fact.FactArray which exists in myjar.jar. myjar.jar is a separate Java project (using NetBeans, but I don't think that's relevant). I include the package in my JSP as follows: <%@ page import="com.mypackage.fact.*" %> I deploy my web site and JSPs into Tomcat 6 as a WAR file. I include myjar.jar in that WAR in WEB-INF/lib but that doesn't work. I tried putting myjar.jar in my tomcat/lib folder, but that doesn't work either. I have bounced the server several times between changes. I have read a whole bunch of questions on here which say "put it in WEB-INF/lib" but that isn't working, so I'm asking my own question. Where do I need to put common JAR files so they get picked up by Tomcat?

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  • Returning the same type the function was passed

    - by Ken Bloom
    I have the following code implementation of Breadth-First search. trait State{ def successors:Seq[State] def isSuccess:Boolean = false def admissableHeuristic:Double } def breadthFirstSearch(initial:State):Option[List[State]] = { val open= new scala.collection.mutable.Queue[List[State]] val closed = new scala.collection.mutable.HashSet[State] open.enqueue(initial::Nil) while (!open.isEmpty){ val path:List[State]=open.dequeue() if(path.head.isSuccess) return Some(path.reverse) closed += path.head for (x <- path.head.successors) if (!closed.contains(x)) open.enqueue(x::path) } return None } If I define a subtype of State for my particular problem class CannibalsState extends State { //... } What's the best way to make breadthFirstSearch return the same subtype as it was passed? Supposing I change this so that there are 3 different state classes for my particular problem and they share a common supertype: abstract class CannibalsState extends State { //... } class LeftSideOfRiver extends CannibalsState { //... } class InTransit extends CannibalsState { //... } class RightSideOfRiver extends CannibalsState { //... } How can I make the types work out so that breadthFirstSearch infers that the correct return type is CannibalsState when it's passed an instance of LeftSideOfRiver? Can this be done with an abstract type member, or must it be done with generics?

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  • Problems compiliing c++ code using cygwin

    - by user343403
    I am trying to compile some source code in cygwin (in windows 7) and get the following error when I run the make file g++ -DHAVE_CONFIG_H -I. -I.. -I.. -Wall -Wextra -Werror -g -O2 -MT libcommon_a Fcntl.o -MD -MP -MF .deps/libcommon_a-Fcntl.Tpo -c -o libcommon_a-Fcntl.o `test -f 'Fcntl.cpp' || echo './'`Fcntl.cpp Fcntl.cpp: In function int setCloexec(int): Fcntl.cpp:8: error: 'F_GETFD' was not declared in this scope Fcntl.cpp:8: error: 'fcntl' was not declared in this scope Fcntl.cpp:11: error: 'FD_CLOEXEC' was not declared in this scope Fcntl.cpp:12: error: 'F_SETFD' was not declared in this scope make[4]: *** [libcommon_a-Fcntl.o] Error 1 make[4]: Leaving directory `/abyss-1.1.2/Common' make[3]: *** [all-recursive] Error 1 make[3]: Leaving directory `/abyss-1.1.2' make[2]: *** [all] Error 2 make[2]: Leaving directory `/abyss-1.1.2' make[1]: *** [.build-conf] Error 2 make[1]: Leaving directory `/cygdrive/c/Users/Martin/Documents/NetBeansProjects/abyss-1.1.2_1' make: *** [.build-impl] Error 2 The problem file is:- #include "Fcntl.h" #include <fcntl.h> /* Set the FD_CLOEXEC flag of the specified file descriptor. */ int setCloexec(int fd) { int flags = fcntl(fd, F_GETFD, 0); if (flags == -1) return -1; flags |= FD_CLOEXEC; return fcntl(fd, F_SETFD, flags); } I don't understand what is going on, the file fcntl.h is available and the varaiables that it says were not declared in this scope do not give an error when I compile the file on its own Any help would be much appreciated Many Thanks

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  • Python script to calculate aded combinations from a dictionary

    - by dayde
    I am trying to write a script that will take a dictionary of items, each containing properties of values from 0 - 10, and add the various elements to select which combination of items achieve the desired totals. I also need the script to do this, using only items that have the same "slot" in common. For example: item_list = { 'item_1': {'slot': 'top', 'prop_a': 2, 'prop_b': 0, 'prop_c': 2, 'prop_d': 1 }, 'item_2': {'slot': 'top', 'prop_a': 5, 'prop_b': 0, 'prop_c': 1, 'prop_d':-1 }, 'item_3': {'slot': 'top', 'prop_a': 2, 'prop_b': 5, 'prop_c': 2, 'prop_d':-2 }, 'item_4': {'slot': 'mid', 'prop_a': 5, 'prop_b': 5, 'prop_c':-5, 'prop_d': 0 }, 'item_5': {'slot': 'mid', 'prop_a':10, 'prop_b': 0, 'prop_c':-5, 'prop_d': 0 }, 'item_6': {'slot': 'mid', 'prop_a':-5, 'prop_b': 2, 'prop_c': 3, 'prop_d': 5 }, 'item_7': {'slot': 'bot', 'prop_a': 1, 'prop_b': 3, 'prop_c':-4, 'prop_d': 4 }, 'item_8': {'slot': 'bot', 'prop_a': 2, 'prop_b': 2, 'prop_c': 0, 'prop_d': 0 }, 'item_9': {'slot': 'bot', 'prop_a': 3, 'prop_b': 1, 'prop_c': 4, 'prop_d':-4 }, } The script would then need to select which combinations from the "item_list" dict that using 1 item per "slot" that would achieve a desired result when added. For example, if the desired result was: 'prop_a': 3, 'prop_b': 3, 'prop_c': 8, 'prop_d': 0, the script would select 'item_2', 'item_6', and 'item_9', along with any other combination that worked. 'item_2': {'slot': 'top', 'prop_a': 5, 'prop_b': 0, 'prop_c': 1, 'prop_d':-1 } 'item_6': {'slot': 'mid', 'prop_a':-5, 'prop_b': 2, 'prop_c': 3, 'prop_d': 5 } 'item_9': {'slot': 'bot', 'prop_a': 3, 'prop_b': 1, 'prop_c': 4, 'prop_d':-4 } 'total': 'prop_a': 3, 'prop_b': 3, 'prop_c': 8, 'prop_d': 0 Any ideas how to accomplish this? It does not need to be in python, or even a thorough script, but just an explanation on how to do this in theory would be enough for me. I have tried working out looping through every combination, but that seems to very quickly get our of hand and unmanageable. The actual script will need to do this for about 1,000 items using 20 different "slots", each with 8 properties. Thanks for the help!

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  • ASP.NET MVC Authorize by Group

    - by Jimmo
    I have what seems like a common issue with SaaS applications, but have not seen this question on here anywhere. I am using ASP.NET MVC with Forms Authentication. I have implemented a custom membership provider to handle logic, but have one issue (perhaps the issue is in my mental picture of the system). As with many SaaS apps, Customers create accounts and use the app in a way that looks like they are the only ones present (they only see their items, users, etc.) In reality, there are generic controllers and views presenting data depending on their account. When calling something like ValidateUser, I have access to their affiliation in the User object - what I don't have is the context of the request to which to compare it. As an example, One company called ABC goes to abc.mysite.com Another company called XYZ goes to xyz.mysite.com When an ABC user calls http://abc.mysite.com/product/edit/12 I have an [Authorize] attribute on the Edit method in the ProductController to make sure he is signed in and has sufficient permission to do so. If that same ABC user tried to access http://xyz.mysite.com/product/edit/12 I would not want to validate him in the context of that call. In the ValidateUser of the MembershipProvider, I have the information about the user, but not about the request. I can tell that the user is from ABC, but I cannot tell that the request is for XYZ at that point in the code. How should I resolve this?

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  • How to use symbols/punctuation characters in discriminated unions

    - by user343550
    I'm trying to create a discriminated union for part of speech tags and other labels returned by a natural language parser. It's common to use either strings or enums for these in C#/Java, but discriminated unions seem more appropriate in F# because these are distinct, read-only values. In the language reference, I found that this symbol ``...`` can be used to delimit keywords/reserved words. This works for type ArgumentType = | A0 // subject | A1 // indirect object | A2 // direct object | A3 // | A4 // | A5 // | AA // | ``AM-ADV`` However, the tags contain symbols like $, e.g. type PosTag = | CC // Coordinating conjunction | CD // Cardinal Number | DT // Determiner | EX // Existential there | FW // Foreign Word | IN // Preposision or subordinating conjunction | JJ // Adjective | JJR // Adjective, comparative | JJS // Adjective, superlative | LS // List Item Marker | MD // Modal | NN // Noun, singular or mass | NNP // Proper Noun, singular | NNPS // Proper Noun, plural | NNS // Noun, plural | PDT // Predeterminer | POS // Possessive Ending | PRP // Personal Pronoun | PRP$ //$ Possessive Pronoun | RB // Adverb | RBR // Adverb, comparative | RBS // Adverb, superlative | RP // Particle | SYM // Symbol | TO // to | UH // Interjection | VB // Verb, base form | VBD // Verb, past tense | VBG // Verb, gerund or persent participle | VBN // Verb, past participle | VBP // Verb, non-3rd person singular present | VBZ // Verb, 3rd person singular present | WDT // Wh-determiner | WP // Wh-pronoun | WP$ //$ Possessive wh-pronoun | WRB // Wh-adverb | ``#`` | ``$`` | ``''`` | ``(`` | ``)`` | ``,`` | ``.`` | ``:`` | `` //not sure how to escape/delimit this ``...`` isn't working for WP$ or symbols like ( Also, I have the interesting problem that the parser returns `` as a meaningful symbol, so I need to escape it as well. Is there some other way to do this, or is this just not possible with a discriminated union? Right now I'm getting errors like Invalid namespace, module, type or union case name Discriminated union cases and exception labels must be uppercase identifiers I suppose I could somehow override toString for these goofy cases and replace the symbols with some alphanumeric equivalent?

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  • Moving .NET assemblies away from the application base directory?

    - by RasmusKL
    I have a WinForms application with a bunch of third party references. This makes the output folder quite messy. I'd like to place the compiled / referenced dlls into a common subdirectory in the output folder, bin / lib - whatever - and just have the executables (+ needed configs etc) reside in the output folder. After some searching I ran into assembly probing (http://msdn.microsoft.com/en-us/library/4191fzwb.aspx) - and verified that if I set this up and manually move the assemblies my application will still work if they are stored in the designated subdirectory like so: <configuration> <runtime> <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1"> <probing privatePath="bin" /> </assemblyBinding> </runtime> </configuration> However, this doesn't solve the build part - is there any way to specify where referenced assemblies and compiled library assemblies go? Only solutions I can think of off the top of my head is either post-build actions or dropping the idea and using ILMerge or something. There has got to be a better way of defining the structure :-)

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  • How to migrate primary key generation from "increment" to "hi-lo"?

    - by Bevan
    I'm working with a moderate sized SQL Server 2008 database (around 120 tables, backups are around 4GB compressed) where all the table primary keys are declared as simple int columns. At present, primary key values are generated by NHibernate with the increment identity generator, which has worked well thus far, but precludes moving to a multiprocessing environment. Load on the system is growing, so I'm evaluating the work required to allow the use of multiple servers accessing a common database backend. Transitioning to the hi-lo generator seems to be the best way forward, but I can't find a lot of detail about how such a migration would work. Will NHibernate automatically create rows in the hi-lo table for me, or do I need to script these manually? If NHibernate does insert rows automatically, does it properly take account of existing key values? If NHibernate does take care of thing automatically, that's great. If not, are there any tools to help? Update NHibernate's increment identifier generator works entirely in-memory. It's seeded by selecting the maximum value of used identifiers from the table, but from that point on allocates new values by a simple increment, without reference back to the underlying database table. If any other process adds rows to the table, you end up with primary key collisions. You can run multiple threads within the one process just fine, but you can't run multiple processes. For comparison, the NHibernate identity generator works by configuring the database tables with identity columns, putting control over primary key generation in the hands of the database. This works well, but compromises the unit of work pattern. The hi-lo algorithm sits inbetween these - generation of primary keys is coordinated through the database, allowing for multiprocessing, but actual allocation can occur entirely in memory, avoiding problems with the unit of work pattern.

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  • Need guidelines for optimizing WebGL performance by minimizing shader changes

    - by brainjam
    I'm trying to get an idea of the practicality of WebGL for rendering large architectural interior scenes, consisting of 100K's of triangles. These triangles are distributed over many objects, and there are many materials in the scene. On the other hand, there are no moving parts. And the materials tend to be fairly simple, mostly based on texture maps. There is a lot of texture map sharing .. for example all the chairs in scene will share a common map. There is also some multitexturing - up to three textures overlaid in a material. I've been doing a little experimentation and reading, and gather that frequently switching materials during a rendering pass will slow things down. For example, a scene with 200K triangles will have significant performance differences, depending on whether there are 10 or 1000 objects, assuming that each time an object is displayed a new material is set up. So it seems that if performance is important the scene should be sorted by materials so as to minimize material switching. What I'm looking for is guidelines on how to think of the overhead of various state changes, and where do I get the biggest bang for the buck. For example, what are the relative performance costs of, say, gl.useProgram(), gl.uniformMatrix4fv(), gl.drawElements() should I try to write ubershaders to minimize shader switching? should I try to aggregate geometry to minimize the number of gl.drawElements() calls I realize that mileage may vary depending on browser, OS, and graphics hardware. And I'm also not looking for heroic measures. Just some guidelines from people who have already had some experience in making scenes fast. I'll add that while I've had some experience with fixed-pipeline OpenGL programming in the past, I'm rather new to the WebGL/OpenGL ES 2.0 way of doing things.

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  • Separating Javascript functions

    - by msharma
    I am wondering how javascripts get included in a jsp - can we put any code which the jsp will recognize and not just javascript code only in the .js file? I have some common javascript code which needs to get executed on different pages, so I decided to place it in its own separate .js file and include it on all jsps which call that function. The js function now refers to a key from a properties file and some other non-javascript code: function openPrivacyStmntWindow(){ var url = <h:outputText escape="false" value="\"#{urls.url_privacyStatement}\";" /> newwindow=window.open(url,'Terms','height=600,width=800,left=300,top=100,scrollbars=1'); newwindow.focus(); return false; } This function worked just fine when it was included in the jsp itself. Now that I have separated it into its own file it doesnt, do I need to include the properties bundle in this file. The value="\"#{urls.url_privacyStatement}\";" is referring to a bundle called "urls" which has a key called "url_privacyStatement" Also in Line 1 var url = <h:outputText escape="false" value="\"#{urls.url_privacyStatement}\";" /> the <h:outputText escape="false" ... /> will it cause any issues? Thanks.

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  • actionscript-3: refactor interface inheritance to get rid of ambiguous reference error

    - by maxmc
    hi! imagine there are two interfaces arranged via composite pattern, one of them has a dispose method among other methods: interface IComponent extends ILeaf { ... function dispose() : void; } interface ILeaf { ... } some implementations have some more things in common (say an id) so there are two more interfaces: interface ICommonLeaf extends ILeaf { function get id() : String; } interface ICommonComponent extends ICommonLeaf, IComponent { } so far so good. but there is another interface which also has a dispose method: interface ISomething { ... function dispose() : void; } and ISomething is inherited by ICommonLeaf: interface ICommonLeaf extends ILeaf, ISomething { function get id() : String; } As soon as the dispose method is invoked on an instance which implements the ICommonComponent interface, the compiler fails with an ambiguous reference error because ISomething has a method called dispose and ILeaf also has a dispose method, both living in different interfaces (IComponent, ISomething) within the inheritace tree of ICommonComponent. I wonder how to deal with the situation if the IComponent, the ILeaf and the ISomething can't change. the composite structure must also work for for the ICommonLeaf & ICommonComponent implementations and the ICommonLeaf & ICommonComponent must conform to the ISomething type. this might be an actionscript-3 specific issue. i haven't tested how other languages (for instance java) handle stuff like this.

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  • magento payment process.. how it works in general

    - by spirytus
    hi everyone, got a question and I hope this is right place to ask :).. don’t quite understand how payment works in magento. client goes to checkout and lets say wants to pay as a guest, so provides address etc. and finally gets to payment methods. Then I want clients to pay thru credit card. Already have module installed for gateway (bank?) of my choice. At that point I would expect users to be redirected to 3rd party page (bank hosted) where they giving all the details, only after being returned to my magento site with appropriate message. In magento however it seems like they need to provide cc numbers and details on magento checkout page. I don’t understand if I (or the payment module I installed) need to transfer then all the credit card details to bank? I would have to have checkout page on ssl connection and static ip right? The thing is I want to avoid touching CC numbers at any point and would love to have it done by a bank page. I like the idea of magento interface all the way without redirecting to another page though, the only problem is not sure if would be able to set it all up properly. If anyone could explain to me possible options, what is the common way to do it and how the whole process works that would be very much appreciated. I did my research and looked all over google and various forums still need someones help though. Please let me know if some parts of my question are not quite clear, will try to better explain if necessary.

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  • What techniques can be used to detect so called "black holes" (a spider trap) when creating a web crawler?

    - by Tom
    When creating a web crawler, you have to design somekind of system that gathers links and add them to a queue. Some, if not most, of these links will be dynamic, which appear to be different, but do not add any value as they are specifically created to fool crawlers. An example: We tell our crawler to crawl the domain evil.com by entering an initial lookup URL. Lets assume we let it crawl the front page initially, evil.com/index The returned HTML will contain several "unique" links: evil.com/somePageOne evil.com/somePageTwo evil.com/somePageThree The crawler will add these to the buffer of uncrawled URLs. When somePageOne is being crawled, the crawler receives more URLs: evil.com/someSubPageOne evil.com/someSubPageTwo These appear to be unique, and so they are. They are unique in the sense that the returned content is different from previous pages and that the URL is new to the crawler, however it appears that this is only because the developer has made a "loop trap" or "black hole". The crawler will add this new sub page, and the sub page will have another sub page, which will also be added. This process can go on infinitely. The content of each page is unique, but totally useless (it is randomly generated text, or text pulled from a random source). Our crawler will keep finding new pages, which we actually are not interested in. These loop traps are very difficult to find, and if your crawler does not have anything to prevent them in place, it will get stuck on a certain domain for infinity. My question is, what techniques can be used to detect so called black holes? One of the most common answers I have heard is the introduction of a limit on the amount of pages to be crawled. However, I cannot see how this can be a reliable technique when you do not know what kind of site is to be crawled. A legit site, like Wikipedia, can have hundreds of thousands of pages. Such limit could return a false positive for these kind of sites. Any feedback is appreciated. Thanks.

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  • Bilinear interpolation - DirectX vs. GDI+

    - by holtavolt
    I have a C# app for which I've written GDI+ code that uses Bitmap/TextureBrush rendering to present 2D images, which can have various image processing functions applied. This code is a new path in an application that mimics existing DX9 code, and they share a common library to perform all vector and matrix (e.g. ViewToWorld/WorldToView) operations. My test bed consists of DX9 output images that I compare against the output of the new GDI+ code. A simple test case that renders to a viewport that matches the Bitmap dimensions (i.e. no zoom or pan) does match pixel-perfect (no binary diff) - but as soon as the image is zoomed up (magnified), I get very minor differences in 5-10% of the pixels. The magnitude of the difference is 1 (occasionally 2)/256. I suspect this is due to interpolation differences. Question: For a DX9 ortho projection (and identity world space), with a camera perpendicular and centered on a textured quad, is it reasonable to expect DirectX.Direct3D.TextureFilter.Linear to generate identical output to a GDI+ TextureBrush filled rectangle/polygon when using the System.Drawing.Drawing2D.InterpolationMode.Bilinear setting? For this (magnification) case, the DX9 code is using this (MinFilter,MipFilter set similarly): Device.SetSamplerState(0, SamplerStageStates.MagFilter, (int)TextureFilter.Linear); and the GDI+ path is using: g.InterpolationMode = InterpolationMode.Bilinear; I thought that "Bilinear Interpolation" was a fairly specific filter definition, but then I noticed that there is another option in GDI+ for "HighQualityBilinear" (which I've tried, with no difference - which makes sense given the description of "added prefiltering for shrinking") Followup Question: Is it reasonable to expect pixel-perfect output matching between DirectX and GDI+ (assuming all external coordinates passed in are equal)? If not, why not? Finally, there are a number of other APIs I could be using (Direct2D, WPF, GDI, etc.) - and this question generally applies to comparing the output of "equivalent" bilinear interpolated output images across any two of these. Thanks!

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  • How to search cvs comment history

    - by Chris Noe
    I am aware of this command: cvs log -N -w<userid> -d"1 day ago" Unfortunately this generates a formatted report with lots of newlines in it, such that the file-path, the file-version, and the comment-text are all on separate lines. Therefore it is difficult to scan it for all occurrences of comment text, (eg, grep), and correlate the matches to file/version. (Note that the log output would be perfectly acceptable, if only cvs could perform the filtering natively.) EDIT: Sample output. A block of text like this is reported for each repository file: RCS file: /data/cvs/dps/build.xml,v Working file: build.xml head: 1.49 branch: locks: strict access list: keyword substitution: kv total revisions: 57; selected revisions: 1 description: ---------------------------- revision 1.48 date: 2008/07/09 17:17:32; author: noec; state: Exp; lines: +2 -2 Fixed src.jar references ---------------------------- revision 1.47 date: 2008/07/03 13:13:14; author: noec; state: Exp; lines: +1 -1 Fixed common-src.jar reference. =============================================================================

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  • Recommended approach to port to ASP.NET MVC

    - by tshao
    I think many of us used to face the same question, what's the best practices to port existing web forms App to MVC. The situation for me is that we'll support both web forms and MVC at the same time. It means, we create new features in MVC, while maintaining legacy pages in web forms, and they're all in a same project. The point is: we want to keep the DRY (do not repeat yourself) principle and reduce duplicate code as much as possible. The ASPX page is not a problem as we only create new features in MVC, but there're still some shared components we want to re-use the both new / legacy pages: Master page UserControl The question here is: Is that possible to create a common master page / usercontrol that could be used in both web forms and MVC? I know that ViewMasterPage inherits from MasterPage and ViewUserControl inherits from UserControl, so it's maybe OK to let both web forms and MVC ASPX page refer to the MVC version. I did some testing and found sometimes it generates errors during the rendering of usercontrols. Any idea / experience you can share with me? Very appreciate to it.

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  • Problem implementing Interceptor pattern

    - by ph0enix
    I'm attempting to develop an Interceptor framework (in C#) where I can simply implement some interfaces, and through the use of some static initialization, register all my Interceptors with a common Dispatcher to be invoked at a later time. The problem lies in the fact that my Interceptor implementations are never actually referenced by my application so the static constructors never get called, and as a result, the Interceptors are never registered. If possible, I would like to keep all references to my Interceptor libraries out of my application, as this is my way of (hopefully) enforcing loose coupling across different modules. Hopefully this makes some sense. Let me know if there's anything I can clarify... Does anyone have any ideas, or perhaps a better way to go about implementing my Interceptor pattern? Update: I came across Spring.NET. I've heard of it before, but never really looked into it. It sounds like it has a lot of great features that would be very useful for what I'm trying to do. Does anyone have any experience with Spring.NET? TIA, Jeremy

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  • ASP.NET MVC Authorize by Subdomain

    - by Jimmo
    I have what seems like a common issue with SaaS applications, but have not seen this question on here anywhere. I am using ASP.NET MVC with Forms Authentication. I have implemented a custom membership provider to handle logic, but have one issue (perhaps the issue is in my mental picture of the system). As with many SaaS apps, customers create accounts and use the app in a way that looks like they are the only ones present (they only see their items, users, etc.). In reality, there are generic controllers and views presenting data depending on the customer represented in the URL. When calling something like the MembershipProvider.ValidateUser, I have access to the user's customer affiliation in the User object - what I don't have is the context of the request to compare whether it is a data request for the same customer as the user. As an example, One company called ABC goes to abc.mysite.com Another company called XYZ goes to xyz.mysite.com When an ABC user calls http://abc.mysite.com/product/edit/12 I have an [Authorize] attribute on the Edit method in the ProductController to make sure he is signed in and has sufficient permission to do so. If that same ABC user tried to access http://xyz.mysite.com/product/edit/12 I would not want to validate him in the context of that call. In the ValidateUser of the MembershipProvider, I have the information about the user, but not about the request. I can tell that the user is from ABC, but I cannot tell that the request is for XYZ at that point in the code. How should I resolve this?

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