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  • Emulating a computer running MS-DOS

    - by Richard
    Writing emulators has always fascinated me. Now I want to write an emulator for an IBM PC and run MS-DOS on it (I've got the floppy image files). I have good experience in C++ and C and basic knowledge of assembler and the architecture of a CPU. I also know that there are thousands of emulators out there doing exactly what I want to do, but I'd be doing this for pure joy only. How much work do I have to expect? (If my goal is to boot DOS and create a text file with it, all emulated) What CPU should I emulate ? Where can I find documentation on how the machine code is organized and which opcodes mean what, so I can unpack and execute them correctly with my emulator? Does MS-DOS still run on the newest generations of processors? Would it theoretically be able to natively run on a 64-bit AMD Phenom 2 processor w/ a modern mainboard, HDD, RAM, etc.? What else, besides emulating the CPU, could be an important factor (in terms of difficulty)? I would only aim for outputting / inputting text to the system via the host system's console, no sound or other more advanced IO etc. Have you written an emulator yet? What was your first one for? How hard was it? Do you have any special tips for me? Thanks in advance

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  • CherryPy always returning HTTP 200 [closed]

    - by DarkArctic
    I'm having a bit of a problem when browsing to a non-existent resource. I get a response code of 200 instead of 404. I'm using the MethodDispatcher and I have a class that overloads the __getattr__ method to instantiate a resource if a child exists or to return AttributeError if one doesn't. My class is always returning the AttributeError correctly, but the data I actually get is always from the last good resource. Here's a simplified (except for __getattr__) version of my class: class BaseResource(object): exposed = True def __init__(self, name): self.children = [] # Pretend this has child resources def __getattr__(self, name): if name in self._children: uuid, application, obj_type, server = self._children[name] try: resource = getattr(app[application], obj_type) except AttributeError as e: raise cherrypy.HTTPError(500, e) return resource(uuid) else: raise AttributeError('Child with name \'{}\' could not be found.'.format(name)) def GET(self): cherrypy.log.error('*** {} not found, raising AttributeError'.format(name)) return 'GET request for {}'.format(self._name) So fetching I get the following when I browse to the following resources: http://localhost:8000/users - This resource exists, so it returns it correctly. http://localhost:8000/users/fake - This returns the "users" resource giving an HTTP 200. http://localhost:8000/users/fake/reallyfake - This returns the "users" resource again. So my question is, where can I start looking to find out why my code isn't returning a 404 for a non-existent resource. I'm sure I've done something wrong, but I'm not sure what. Whatever I did wrong I've undone and I'm now getting a 404 returned correctly. I'm sorry I can't give any detail on what the issue was, but I'm honestly not sure what I did.

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  • Log session and session changes of a asp.net web user

    - by Johan Wikström
    This is going to be a quite broad question, and any suggestions, examples, links are very welcome! I'm looking for a good way to log my users session, and actions on the site up to a certain point. The site in question is a site for doing bookings. The users start with doing a search, doing a few steps of data gathering and selections and end up with a booking. So what I need to implement is some kind of logging of the current session variables at each step the user takes. And perhaps some other valid information. Logging should preferably be done to the a database. At the end i would like to associate all these session with a booking reference. The goal is to later if something goes wrong with the booking or we need to investigate a situation have all information we need. I understand log4net is a popular choice for logging, and used it a bit myself for simple purposes, but can not find any good examples regarding my situation. This should be a common situation, i'm curious how others do it.

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  • Where can I find a powerful, standards compliant, web-based interactive org chart API?

    - by Adam Soltys
    Hi, I'm looking to build an interactive web-based org chart for a large organization. I somewhat like the interface at ancestry.com where you can hover over people and pan/zoom around and click on different nodes to make them the root. Ideally, I'd like it if people could belong to multiple organizational entities like committees, working groups, etc. In other words the API should support graphs in general, not just trees. I'd like to be able to visually explode each organizational substructure into substituents by clicking on it, with a nice animation of the employees ballooning or spilling out so you can really interactively drill down through the organization. I found http://code.google.com/apis/visualization/documentation/gallery/orgchart.html but it looks a bit rudimentary. I know there are desktop tools like OrgPlus and Visio that can build static charts but I'm really looking for a free, web-based API with open standards-based output like SVG or HTML5 Canvas elements rather than Flash or some proprietary output. Something I can embed into a custom web application and style myself. Something interactive.

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  • Pagination in Joomla!

    I'm a bit new to Joomla! and I'm building my new web site using Joomla! 1.5.8 with a template bought from RocketTheme. The long article in question is a gallery of photos, and I wanted to create a horizontal pagination nav-bar in the footer of the gallery, I just clicked pagebreak where I wanted to paginate in my article in the WYSIWYG editor and thought that it's actually all I have to do. What I got was ugly; a vertically directed navigation bar placed in the top right side of my gallery with the links to each part of the article, the all without the minimum styling. And as I see it's a table! Why not outputting a list instead of a table! (Well this is not actually my concern right now). I can understand CSS and html, but I'm not really a PHP guy, so I don't understand how to use pagination.php or pagenavigation.php! Do I have to customize one of them to have my nav-bar? What I have to do to get that horizontal nav-bar? Really thanks in advance. Wassim

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  • Identity alternative for SQL Azure Federation : are Azure Queues or Service Bus Queues a good choice?

    - by JYL
    As many of developers, I'm looking for a way to integrate my existing app to SQL Azure Federations, and replacing the Identity columns (the primary keys of my tables) is a big problem. For many reasons, I do NOT want use GUID for my primary keys (please don't open the debate about the GUID or not, it's not my question : i just don't want a GUID, period). So I need to build a key provider to replace the "identity" feature of a standard SQL database. I'm using Entity Framework, so i can easily find one place to set the Id value just before the insert (by overriding the SaveChanges method of my ObjectContext class). I just need to find a "not too complicated" implementation for getting the current Id, which is "farm-ready". I've read this SO post : "ID Generation for Sharded Database (Azure Federated Database)" and "Synchronizing Multiple Nodes in Windows Azure from MSDN Magazine", but this solution sounds a bit complicated for me. I'm thinking about creating (automatically) one azure queue for each SQL table, which contain a pre-loaded list of consecutive integer. When I want an Id value, I just have to get a message from the queue (which becomes invisible and is deleted on the way), which give me the current available Id. About the choice between "Windows Azure Queues" and "Windows Azure Service Bus Queues", I prefere "Windows Azure Queues", due to the "high" latency of Service Bus Queues. I don't think that the lack of "ordering garantee" of Azure Queues is a problem. What do you think about that idea of using Azure Queues to provide Id values ? Do you see any argument to give up that idea ? Do you have a better idea, or even a good practice, to provider integer ids in SQL Azure Federation databases ? Thanks.

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  • 3 questions about JSON-P format.

    - by Tristan
    Hi, I have to write a script which will be hosted on differents domains. This script has to get information from my server. So, stackoverflow's user told me that i have to use JSON-P format, which, after research, is what i'm going to do. (the data provided in JSON-P is for displaying some information hosted on my server on other website) How do I output JSON-P from my server ? Is it the same as the json_encode function from PHP How do i design the tree pattern for the output JSON-P (you know, like : ({"name" : "foo", "id" : "xxxxx", "blog" : "http://xxxxxx.com"}); can I steal this from my XML output ? (http://bit.ly/9kzBDP) Each time a visitor browse a website on which my widget is it'll make a request on my server, requesting the JSON-P data to display on the client side. It'll increase dramatically the CPU load (1 visitor on the website who will have the script = 1 SQL request on my server to output data), so is there any way to 'caching' the JSON-P information output to refresh it only one or twice a day and stores it into a 'file' (in which extension?). BUT on the other hand i would say that requesting the JSON-P data directly (without caching it) is a plus, because, websites which will integrates the script only want to display THEIR information and not the whole data. So, making a script with something like that: jQuery.getJSON("http://www.something.com/json-p/outpout?filter=5&callback=?", function(data) { ................); }); Where filter= the information the website wants to display What do you think ? Thank you very much ;)

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  • Detect mouseover and show tooltip text for dots on an HTML Canvas

    - by carl asquith
    Ive recently created a "map" although not very sophisticated (im working on it) it has the basic function and is generally heading in the right direction. If you look at it you can see a tiny red dots and on those tiny red dots i want to mouseover it and see text basically but ive had a bit of trouble getting the code right. http://hummingbird2.x10.mx/website%20creation/mainpage.htm This is all the code so far. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Oynx Warrior</title> <link rel="stylesheet" type="text/css" href="mystyle.css" /> </head> <body> <h1>Oynx Warrior</h1> <canvas id="myCanvas" width="500" height="500" style="border:1px solid #c3c3c3;"> Your browser does not support the canvas element. </canvas> <script type="text/javascript"> var c=document.getElementById("myCanvas"); var cxt=c.getContext("2d"); cxt.fillStyle="#red"; cxt.beginPath(); cxt.arc(50,50,1,0,Math.PI*2,true); cxt.closePath(); cxt.fill(); </script> </body> </html>

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  • Regularly update database without browser/user

    - by Chris M
    I currently have a MySQL database which I was hoping to use to store regularly updated data from a temperature sensor connected to the internet. I currently have a page that, when opened, will grab the current temperature and the current timestamp and add it as an entry to the database, but I was looking for a way to do that without me refreshing the page every 5 seconds. Detail: The data comes from an Arduino Ethernet, posted to an IP address. Currently, I'm using cURL to grab the data from the IP, add a timestamp and save it to the DB. Obviously only updates when the page is refreshed (it uses PHP). Here is a live feed of the data - http://wetdreams.org.uk/ChrisProject/UI/live_graph_two.html TL;DR - Basically I need a middle man to grab the data from the IP and post it to a MySQL Edit: Thanks for all the advice. There might be a little bit of confusion, I'm looking for a solution that (ideally) doesn't require a computer to be on at all (other than the Server containing Database). Since I'm looking to store data over long periods of time (weeks), I'd like to set it up and leave a script running on the server (or Arduino) that gets the temp and posts it to the Database. In my head I would like to have a page on the server that automatically (without any browser open, or any other prompting other than a timer) calls a PHP script. Hope that clears things up!

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  • Error with zoomStartTime and AnnotatedTimeLine

    - by user973025
    I'm a bit of a beginner with Javascript, but last month I had a working Google chart linked to a Google Docs file, which uses a start date for the graph at 90 days before the current date. I checked the page today and in Chrome I get the message "Object # has no method 'getTime'", and in Firefox I get the message "b.zoomStartTime[y] is not a function". Both stop the graph from loading. I have simplified the code to help me with the error, but I'm not getting anywhere... Here's the code: <script type="text/javascript"> var oldDate = new Date(); oldDate.setDate(oldDate.getDate() - 90); </script> <script type="text/javascript" src="//ajax.googleapis.com/ajax/static/modules/gviz/1.0/chart.js"> { "dataSourceUrl": "//docs.google.com/spreadsheet/tq?key=0AkQH6d2CUv_qdDhwd3gtZzdTVFlNX3AwX2xUSUVuclE&transpose=0&headers=-1&range=A1%3AB2436&gid=0&pub=1", "options": { "zoomStartTime": oldDate, "width": 650, "height": 371 }, "chartType": "AnnotatedTimeLine", } </script> Any ideas would be hugely appreciated. David.

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  • How do I vertcally align thumbnails of unknown height using jQuery?

    - by playahabana
    Ok, I am a complete beginner to this, in fact I am still building my first website. I am attempting to do this all by hand-coding without a CMS in order to try and learn as much possible as quickly as possible. If this post is in the wrong place I apologise, and a pointer to right place would be appreciated. Here goes, I am trying to peice together a bit of jQuery that will automatically vertically align my thumbnails in my image gallery (they are all different sizes). They are within fixed size div's and the function I am attempting looks something like this: <script type="text/javascript"> $('#ul.photo).bind(function() { var smartVert=$(this); var phty=ob.("ul.photo img").height(); //get height of photos var phtdif=Math.floor(208 - phty); //subtract height of photo from div height var phttop=Math.floor(phtdif / 2); //gets padding reqd. $ob.("ul.photo").css({'padding-top' : phttop}) //sets padding to center thumbnail }); smartVert(); unsurprisingly this doesn't work, if some kindly soul could take pity on a total noob, and point out where I am going wrong (probably in writing complete gibberish would be my first guess) it would be greatly appreciated- even if you could just point me in the direcion of a tutorial regarding these things, I have looked and found one reference that said such a function was easy to create, but it did not elaborate. thankyou in advance

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  • Google maps and J-Query: Individual markers?

    - by user351189
    Hi there, I have created a Google maps mashup, where with a bit of input, I have managed to have a sidebar that links to a video icon/marker that then opens up an info window showing virtual tours. I would, however, like to put different coloured marker icons on the map depending on the category that the video is in. This would be easy enough to do, but my page is made up of a mixture of J-Query and JavaScript all calling to the individual flash files. Could someone help me with the code for adding extra marker icons for different categories? Here is the code: So, after the intial 'var camera;' point, there comes this: function addMarker(point, title, video, details) { var marker = new GMarker(point, {title: title, icon:camera}); GEvent.addListener(marker, "click", function() { if (details) { marker.openInfoWindowTabsHtml([new GInfoWindowTab("Video", video), new GInfoWindowTab("More", details)]); } else { marker.openInfoWindowHtml(video); } }); Then further down, is the code for calling the individual marker image. I would like to add another image to this list - would I start out by calling the new object 'camera-red.image' or something similar? function initialize() { if (GBrowserIsCompatible()) { map = new GMap2(document.getElementById("mapDiv")); map.setCenter(new GLatLng(51.52484592590448, -0.13345599174499512), 17); map.setUIToDefault(); var uclvtSatMapType = createUclVTSatMapType() map.addMapType(uclvtSatMapType); map.setMapType(uclvtSatMapType); camera = new GIcon(G_DEFAULT_ICON); camera.image = "ucl-video.png"; camera.iconSize = new GSize(32,37); camera.iconAnchor = new GPoint(16,35); camera.infoWindowAnchor = new GPoint(16,2); addMarkersToMap(); } The actual map can be found here: link text Thanks. Gray

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  • Write to the second line of a PHP file

    - by Woz
    I have a php file that I want to add an include path to on the second line. I need to open the file and inset a line of code on line 2. I have tried a few techniques none of which are working but I think it has something to do with the text I am trying to write and possibly not escaping character correctly as I am not too familiar with file writing. So here is the file I want to write to: $file = $_SERVER['DOCUMENT_ROOT'].'/'.$domaindir.'/test.php'; Here is the piece of text I want to insert into the file: $dbfile = "include('".$_SERVER['DOCUMENT_ROOT']."/".$domaindir."/web_".$dbname.".inc.php');"; Then what I was doing was a string replace but all it did was bump the "session_start();" bit to a newline! Can anyone point me in the direction of a tutorial that might tell me how to insert this into the second line of my php file or indeed if anyone has any ideas? I can say for sure that the path to the PHP file is fully tested so i know its not that the file is not being open or written to. Any ideas would be much appreciated. Thanks in advance.

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  • visual analysis of web pages in ruby

    - by Clint Miller
    I'm looking to write some code that does visual analysis of web pages, preferably using Ruby. My code will need to be able to determine the top, left, width, height, background color, color, and font size for all the elements in the DOM. Of course, these values can only be calculated once all CSS is applied. So, I don't think that Nokogiri is up for the job. Ultimately, I'm trying to use this data in a VIPS-like (Vision-Based Page Segmentation) algorithm in an attempt to find the main content in downloaded news articles. I've considered using Watir to drive Chrome or Firefox and then extract the data. The problem is that browsers can't be run headless through Watir (I think). Ultimately, this code will be running on an array of Linux servers in a data center. So, the code won't have easy access to an X Server for displaying the browser. I suppose one solution is to use Watir and run a headless X Server on the Linux servers. That's a bit of a pain, but it looks like my best option right now. Does anyone have any better ideas?

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  • Subquery with multiple results combined into a single field?

    - by Todd
    Assume I have these tables, from which i need to display search results in a browser: Table: Containers id | name 1 Big Box 2 Grocery Bag 3 Envelope 4 Zip Lock Table: Sale id | date | containerid 1 20100101 1 2 20100102 2 3 20091201 3 4 20091115 4 Table: Items id | name | saleid 1 Barbie Doll 1 2 Coin 3 3 Pop-Top 4 4 Barbie Doll 2 5 Coin 4 I need output that looks like this: itemid itemname saleids saledates containerids containertypes 1 Barbie Doll 1,2 20100101,20100102 1,2 Big Box, Grocery Bag 2 Coin 3,4 20091201,20091115 3,4 Envelope, Zip Lock 3 Pop-Top 4 20091115 4 Zip Lock The important part is that each item type only gets one record/row in the return on the screen. I accomplished this in the past by returning multiple rows of the same item and using a scripting language to limit the output. However, this makes the ui overly complicated and loopy. So, I'm hoping I can get the database to spit out only as many records as there are rows to display. This example may be a bit extreme because of the 2 joins needed to get to the container from the item (through the sale table). I'd be happy for just an example query that outputs this: itemid itemname saleids saledates 1 Barbie Doll 1,2 20100101,20100102 2 Coin 3,4 20091201,20091115 3 Pop-Top 4 20091115 I can only return a single result in a subquery, so I'm not sure how to do this.

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  • SQL developer here -- Nesting with select * finicky in Oracle 10g?

    - by John Sullivan
    I am writing a simple diagnostic query I will execute in my Oracle 10g scratchpad. I am trying to do this as part of a step to build the query. In the SQL Scratchpad for Oracle 10g Enterprise Manager Console, this statement runs fine. SELECT * FROM v$session sess, v$sql sql WHERE sql.sql_id(+) = sess.sql_id and sql.sql_text <> ' ' If I try to wrap that up in Select * from () tb2 I get an error, "ORA-00918: Column Ambiguously Defined". I didn't think that could ever happen with this kind of statement so I am a bit confused. select * from (SELECT * FROM v$session sess, v$sql sql WHERE sql.sql_id(+) = sess.sql_id and sql.sql_text <> ' ') tb2 You should always be able to select * from the result set of another select * statement using this structure as far as I'm aware... right? Is Oracle/10g/the scratchpad trying to force me to accept a certain syntactic structure to prevent excessive nesting? Is this a bug in scratchpad or something about how oracle works?

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  • Deterministic floating point and .NET

    - by code2code
    How can I guarantee that floating point calculations in a .NET application (say in C#) always produce the same bit-exact result? Especially when using different versions of .NET and running on different platforms (x86 vs x86_64). Inaccuracies of floating point operations do not matter. In Java I'd use strictfp. In C/C++ and other low level languages this problem is essentially solved by accessing the FPU / SSE control registers but that's probably not possible in .NET. Even with control of the FPU control register the JIT of .NET will generate different code on different platforms. Something like HotSpot would be even worse in this case... Why do I need it? I'm thinking about writing a real-time strategy (RTS) game which heavily depends on fast floating point math together with a lock stepped simulation. Essentially I will only transmit user input across the network. This also applies to other games which implement replays by storing the user input. Not an option are: decimals (too slow) fixed point values (too slow and cumbersome when using sqrt, sin, cos, tan, atan...) update state across the network like an FPS: Sending position information for hundreds or a few thousand units is not an option Any ideas?

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  • Absence of property syntax in Java

    - by Vojislav Stojkovic
    C# has syntax for declaring and using properties. For example, one can declare a simple property, like this: public int Size { get; set; } One can also put a bit of logic into the property, like this: public string SizeHex { get { return String.Format("{0:X}", Size); } set { Size = int.Parse(value, NumberStyles.HexNumber); } } Regardless of whether it has logic or not, a property is used in the same way as a field: int fileSize = myFile.Size; I'm no stranger to either Java or C# -- I've used both quite a lot and I've always missed having property syntax in Java. I've read in this question that "it's highly unlikely that property support will be added in Java 7 or perhaps ever", but frankly I find it too much work to dig around in discussions, forums, blogs, comments and JSRs to find out why. So my question is: can anyone sum up why Java isn't likely to get property syntax? Is it because it's not deemed important enough when compared to other possible improvements? Are there technical (e.g. JVM-related) limitations? Is it a matter of politics? (e.g. "I've been coding in Java for 50 years now and I say we don't need no steenkin' properties!") Is it a case of bikeshedding?

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  • Why can’t PHP script write a file on server 2008 via command line or task scheduler?

    - by rg89
    I created a question on serverfault.com, and it was recommended that I ask here. http://serverfault.com/questions/140669/why-cant-php-script-write-a-file-on-server-2008-via-command-line-or-task-schedul I have a PHP script. It runs well when I use a browser. It writes an XML file in the same directory. The script takes ~60 seconds to run, and the resulting XML file is ~16 MB. I am running PHP 5.2.13 via FastCGI on Windows Server Web edition SP1 64 bit. The code pulls inventory from SQL server, runs a loop to build an XML file for a third party. I created a task in task scheduler to run c:\php5\php.exe "D:\inetpub\tools\build.php" The task scheduler shows a time lapse of about a minute, which is how long the script takes to run in a browser. No error returned, but no file created. Each time I make a change to the scheduled task properties, a user password box comes up and I enter the administrator account password. If I run this same path and argument at a command line it does not error and does not create the file. When I right click run command prompt as an administrator, the file is still not created. I get my echo statement "file published" that is after the file creation and no error is returned. I am doing a simple fopen fwrite fclose to save the contents of a php variable to a .xml file, and the file only gets created when the script is run through the browser. Here's what happens after the xml-building loop: $feedContent .= "</feed"; sqlsrv_close( $conn ); echo "<p>feed built</p>"; $feedFile = "feed.xml"; $handler = fopen($feedFile, 'w'); fwrite( $handler, $feedContent ); fclose( $handler ); echo "<p>file published</p>"; Thanks

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  • Can a PHP object respond to an undefined method?

    - by Nathan Long
    Rails relies on some of the neat aspects of Ruby. One of those is the ability to respond to an undefined method. Consider a relationship between Dog and Owner. Owner has_many :dogs and Dog belongs_to :owner. If you go into script/console, get a dog object with fido = Dog.find(1), and look at that object, you won't see a method or attribute called Owner. What you will see is an owner_id. And if you ask for fido.owner, the object will do something like this (at least, this is how it appears to me): I'm being asked for my .owner attribute. I don't have one of those! Before I throw a NoMethodError, do I have a rule about how to deal with this? Yes, I do: I should check and see if I have an owner_id. I do! OK, then I'll do a join and return that owner object. PHP's documentation is - ahem - a bit lacking sometimes, so I wonder if anyone here knows the answer to this: Can I define similar behavior for objects in PHP? If not, do you know of a workaround for flexible model joins like these?

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  • Reverse engineering and redistributing code from .NET Framework

    - by ToxicAvenger
    Once or twice I have been running into the following issue: Classes I want to reuse in my applications (and possibly redistribute) exist in the .NET Framework assemblies, but are marked internal or private. So it is impossible to reuse them directly. One way is to disassemble them, pick the pieces you need, put them in a different namespace, recompile (this can be some effort, but usually works quite well). My question is: Is this legal? Is this only legal for the classes of the Framework which are available as source code anyway? Is it illegal? I think that Microsoft marks them internal or private primarily so that they don't have to support them or can change the interfaces later. But some pieces - be it SharePoint or WCF - are almost impossible to properly extend by only using public classes from the apis. And rewriting everything from scratch generates a huge amount of effort, before you even start solving the problem you intended to solve. This is in my eyes not a "dirty" approach per se. The classes Microsoft ships are obviously well tested, if I reuse them under a different namespace I have "control" over them. If Microsoft changes the original implementation, my code won't be affected (some internals in WCF changed quite a bit with v4). It is not a super-clean approach. I would much prefer Microsoft making several classes public, because there are some nice classes hidden inside the framework.

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  • dynamic inheritance without touching classes

    - by Jasper
    I feel like the answer to this question is really simple, but I really am having trouble finding it. So here goes: Suppose you have the following classes: class Base; class Child : public Base; class Displayer { public: Displayer(Base* element); Displayer(Child* element); } Additionally, I have a Base* object which might point to either an instance of the class Base or an instance of the class Child. Now I want to create a Displayer based on the element pointed to by object, however, I want to pick the right version of the constructor. As I currently have it, this would accomplish just that (I am being a bit fuzzy with my C++ here, but I think this the clearest way) object->createDisplayer(); virtual void Base::createDisplayer() { new Displayer(this); } virtual void Child::createDisplayer() { new Displayer(this); } This works, however, there is a problem with this: Base and Child are part of the application system, while Displayer is part of the GUI system. I want to build the GUI system independently of the Application system, so that it is easy to replace the GUI. This means that Base and Child should not know about Displayer. However, I do not know how I can achieve this without letting the Application classes know about the GUI. Am I missing something very obvious or am I trying something that is not possible?

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  • How to lazy load a data structure (python)

    - by Anton Geraschenko
    I have some way of building a data structure (out of some file contents, say): def loadfile(FILE): return # some data structure created from the contents of FILE So I can do things like puppies = loadfile("puppies.csv") # wait for loadfile to work kitties = loadfile("kitties.csv") # wait some more print len(puppies) print puppies[32] In the above example, I wasted a bunch of time actually reading kitties.csv and creating a data structure that I never used. I'd like to avoid that waste without constantly checking if not kitties whenever I want to do something. I'd like to be able to do puppies = lazyload("puppies.csv") # instant kitties = lazyload("kitties.csv") # instant print len(puppies) # wait for loadfile print puppies[32] So if I don't ever try to do anything with kitties, loadfile("kitties.csv") never gets called. Is there some standard way to do this? After playing around with it for a bit, I produced the following solution, which appears to work correctly and is quite brief. Are there some alternatives? Are there drawbacks to using this approach that I should keep in mind? class lazyload: def __init__(self,FILE): self.FILE = FILE self.F = None def __getattr__(self,name): if not self.F: print "loading %s" % self.FILE self.F = loadfile(self.FILE) return object.__getattribute__(self.F, name) What might be even better is if something like this worked: class lazyload: def __init__(self,FILE): self.FILE = FILE def __getattr__(self,name): self = loadfile(self.FILE) # this never gets called again # since self is no longer a # lazyload instance return object.__getattribute__(self, name) But this doesn't work because self is local. It actually ends up calling loadfile every time you do anything.

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  • How does this Bookmarklet allow you to stay signed into this site?

    - by Abs
    Hello all, I have come across Evernote's bookmarklet and was wondering how this worked. You can just drag it to your bookmark and go to any webpage, click that bookmarklet and it will first ask you to login in. All this I have done already and know how it works. The bit that I don't understand is that when you log in they authenticate you and allow you to submit stuff (in this case, a site url etc). When you are done the bookmarklet which placed a small overlay on the page you are viewing disappears. When you go to a new tab and use the bookmarklet again you are still logged in! How? I can see they are using an iFrame when their bookmarklet loads the overlay onto the page - but do they set cookies or something? If so, is this secure? Anyone can change the values? Or are they using some sort of private/public key system Btw, I would like to replicate this Bookmarklet using PHP/Javascript(JQuery maybe). I would appreciate if anyone can help me understand how they do this or point me to relevant tutorials. Thanks all for any help.

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  • Codeigniter PHP - loading a view at an anchor point

    - by James Billings
    I have a form at the bottom of a long page, if a user fills out the form but it doesn't validate the page is reloaded in the typical codeigniter fashion: $this->load->view('template',$data); however because the form is way down at the bottom of the page I need the page to load down there like you do with HTML anchors. Does anyone know how to do this in codeigniter? I can't use the codeigniter redirect(); function because it loses the object and the validation errors are gone. Other frameworks I've used like Yii you can call the redirect function like: $this->redirect(); which solves the problem because you keep the object. I've tried using: $this->index() within the controller which works fine as a redirect but the validation errors are in another method which is where the current page is loaded from: $this->item($labs) but when I use this it get stuck in a loop Any ideas? I've seen this question a lot on the net but no clear answers. I'm researching using codeigniter "flash data" but think it's a bit overkill. cheers.

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