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  • Please , Explain these java code ..?

    - by soma
    I want understand these code before java lab exam especially methode import javax.swing.; import java.util.; import java.text.*; public class EnglishCalendar { public static String[] months = { "January" , "February" , "March", "April" , "May" , "June", "July" , "August" , "September", "October" , "November" , "December" }; public static int days[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; private void showMonth(int m, int y) { int lead_spaces = 0; if (m < 0 || m > 11) { System.out.println("It should be 1 to 12"); } else { System.out.println(); System.out.println(" " + months[m] + " " + y); System.out.println(); GregorianCalendar cal = new GregorianCalendar(y, m, 0); System.out.println("Su Mo Tu We Th Fr Sa "); lead_spaces = cal.get(Calendar.DAY_OF_WEEK); int day_of_month = days[m]; if (cal.isLeapYear(cal.get(Calendar.YEAR)) && m == 1){ day_of_month++;} for (int i = 0; i < lead_spaces; i++) { System.out.print(" "); } for (int i = 1; i <= day_of_month; i++) { if (i < 10) System.out.print(" "); System.out.print(i); if ((lead_spaces + i) % 7 == 0) { System.out.println(); } else { System.out.print(" "); } } System.out.println(); } } private static void doSimpleDateFormat() { Calendar now = Calendar.getInstance(); SimpleDateFormat formatter = new SimpleDateFormat("E yyyy.MM.dd 'at' hh:mm:ss a zzz"); System.out.print(" \n It is now : " + formatter.format(now.getTime())); System.out.println(); } public static void main(String[] args) { String mo = JOptionPane.showInputDialog("Month"); String ye = JOptionPane.showInputDialog("Year"); int mon = new Integer(mo).intValue(); int yea = new Integer(ye).intValue(); EnglishCalendar k = new EnglishCalendar(); k.showMonth(mon - 1 , yea); doSimpleDateFormat(); } }

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  • No more memory available in Mathematica, Fit the parameters of system of differential equation

    - by user1058051
    I encountered a memory problem in Mathematica, when I tried to process my experimental data. It's a system of two differential equations and I need to find most suitable parameters. Unfortunately I am not a Pro in Mathematica, so the program used a lot of memory, when the parameter epsilon is more than 0.4. When it less than 0.4, the program work properly. The command 'historylength = 0' and attempts to reduce the Accuracy Goal and WorkingPrecision didn`t help. I can't use ' clear Cache ', because there isnt a circle. I'm trying to understand what mistakes I made, and how I may limit the memory usage. I have already bought extra-RAM, now its 4GB, and now I haven't free memory-slots in motherboard Remove["Global`*"]; T=13200; L = 0.085; e = 0.41; v = 0.000557197; q = 0.1618; C0 = 0.0256; R = 0.00075; data = {{L,600,0.141124587},{L,1200,0.254134509},{L,1800,0.342888644}, {L,2400,0.424476295},{L,3600,0.562844542},{L,4800,0.657111356}, {L,6000,0.75137817},{L,7200,0.815876516},{L,8430,0.879823594}, {L,9000,0.900771775},{L,13200,1}}; model[(De_)?NumberQ, (Kf_)?NumberQ, (Y_)?NumberQ] := model[De, Kf, Y] = yeld /.Last[Last[ NDSolve[{ v (Ci^(1,0))[z,t]+(Ci^(0,1))[z,t]== -((3 (1-e) Kf (Ci[z,t]-C0))/ (R e (1-(R Kf (1-R/r[z,t]))/De))), (r^(0,1))[z,t]== (R^2 Kf (Ci[z,t]-C0))/ (q r[z,t]^2 (1-(R Kf (1-R/r[z,t]))/De)), (yeld^(0,1))[z,t]== Y*(v e Ci[z,t])/(L q (1-e)), r[z,0]==R, Ci[z,0]==0, Ci[0,t]==0, yeld[z,0]==0}, {r[z,t],Ci[z,t],yeld},{z,0,L},{t,0,T}]]] fit = FindFit[data, {model[De, Kf, Y][z, t], {Y > 0.97, Y < 1.03, Kf > 10^-6, Kf < 10^-4, De > 10^-13, De < 10^-9}}, {{De,7*10^-13}, {Kf, 10^-5}, {Y, 1}}, {z, t}, Method -> NMinimize] data = {{600,0.141124587},{1200,0.254134509},{1800,0.342888644}, {2400,0.424476295},{3600,0.562844542},{4800,0.657111356}, {6000,0.75137817},{7200,0.815876516},{8430,0.879823594}, {9000,0.900771775},{13200,1}}; YYY = model[ De /. fit[[1]], Kf /. fit[[2]], Y /. fit[[3]]]; Show[Plot[Evaluate[YYY[L,t]],{t,0,T},PlotRange->All], ListPlot[data,PlotStyle->Directive[PointSize[Medium],Red]]] the link on the .nb file http://www.4shared.com/folder/249TSjlz/_online.html

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  • How should I ethically approach user password storage for later plaintext retrieval?

    - by Shane
    As I continue to build more and more websites and web applications I am often asked to store user's passwords in a way that they can be retrieved if/when the user has an issue (either to email a forgotten password link, walk them through over the phone, etc.) When I can I fight bitterly against this practice and I do a lot of ‘extra’ programming to make password resets and administrative assistance possible without storing their actual password. When I can’t fight it (or can’t win) then I always encode the password in some way so that it at least isn’t stored as plaintext in the database—though I am aware that if my DB gets hacked that it won’t take much for the culprit to crack the passwords as well—so that makes me uncomfortable. In a perfect world folks would update passwords frequently and not duplicate them across many different sites—unfortunately I know MANY people that have the same work/home/email/bank password, and have even freely given it to me when they need assistance. I don’t want to be the one responsible for their financial demise if my DB security procedures fail for some reason. Morally and ethically I feel responsible for protecting what can be, for some users, their livelihood even if they are treating it with much less respect. I am certain that there are many avenues to approach and arguments to be made for salting hashes and different encoding options, but is there a single ‘best practice’ when you have to store them? In almost all cases I am using PHP and MySQL if that makes any difference in the way I should handle the specifics. Additional Information for Bounty I want to clarify that I know this is not something you want to have to do and that in most cases refusal to do so is best. I am, however, not looking for a lecture on the merits of taking this approach I am looking for the best steps to take if you do take this approach. In a note below I made the point that websites geared largely toward the elderly, mentally challenged, or very young can become confusing for people when they are asked to perform a secure password recovery routine. Though we may find it simple and mundane in those cases some users need the extra assistance of either having a service tech help them into the system or having it emailed/displayed directly to them. In such systems the attrition rate from these demographics could hobble the application if users were not given this level of access assistance, so please answer with such a setup in mind. Thanks to Everyone This has been a fun questions with lots of debate and I have enjoyed it. In the end I selected an answer that both retains password security (I will not have to keep plain text or recoverable passwords), but also makes it possible for the user base I specified to log into a system without the major drawbacks I have found from normal password recovery. As always there were about 5 answers that I would like to have marked correct for different reasons, but I had to choose the best one--all the rest got a +1. Thanks everyone!

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  • Persistence scheme & state data for low memory situations (iphone)

    - by Robin Jamieson
    What happens to state information held by a class's variable after coming back from a low memory situation? I know that views will get unloaded and then reloaded later but what about some ancillary classes & data held in them that's used by the controller that launched the view? Sample scenario in question: @interface MyCustomController: UIViewController { ServiceAuthenticator *authenticator; } -(id)initWithAuthenticator:(ServiceAuthenticator *)auth; // the user may press a button that will cause the authenticator // to post some data to the service. -(IBAction)doStuffButtonPressed:(id)sender; @end @interface ServiceAuthenticator { BOOL hasValidCredentials; // YES if user's credentials have been validated NSString *username; NSString *password; // password is not stored in plain text } -(id)initWithUserCredentials:(NSString *)username password:(NSString *)aPassword; -(void)postData:(NSString *)data; @end The app delegate creates the ServiceAuthenticator class with some user data (read from plist file) and the class logs the user with the remote service. inside MyAppDelegate's applicationDidFinishLaunching: - (void)applicationDidFinishLaunching:(UIApplication *)application { ServiceAuthenticator *auth = [[ServiceAuthenticator alloc] initWithUserCredentials:username password:userPassword]; MyCustomController *controller = [[MyCustomController alloc] initWithNibName:...]; controller.authenticator = auth; // Configure and show the window [window addSubview:..]; // make everything visible [window makeKeyAndVisible]; } Then whenever the user presses a certain button, 'MyCustomController's doStuffButtonPressed' is invoked. -(IBAction)doStuffButtonPressed:(id)sender { [authenticator postData:someDataFromSender]; } The authenticator in-turn checks to if the user is logged in (BOOL variable indicates login state) and if so, exchanges data with the remote service. The ServiceAuthenticator is the kind of class that validates the user's credentials only once and all subsequent calls to the object will be to postData. Once a low memory scenario occurs and the associated nib & MyCustomController will get unloaded -- when it's reloaded, what's the process for resetting up the 'ServiceAuthenticator' class & its former state? I'm periodically persisting all of the data in my actual model classes. Should I consider also persisting the state data in these utility style classes? Is that the pattern to follow?

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  • Freemarker rendering differently on IE8

    - by scphantm
    we have a template that uses this for the record line <input type="${inputType}" name="${variableName}.code" id="${variable}.${vnum}.${answer.code}" class="checkbox" value="${answer.code}" [#nested/] [#if (answer.textLength > 0) && scripting]onchange="showOtherBox( this, '${variable}.[#if descriptionHack]${variableNumber}[#else]${vnum}[/#if].${answer.code}.description' )"[/#if] [#if showValues && (existing == answer.code)]checked="checked"[/#if]/> On IE8 it renders as this <span class="field"> <INPUT id=responses.8.L class=checkbox value=L type=checkbox name="responses['8'].answers['L'].code"> <LABEL for=responses.8.L>Award(s) for special accomplishment or performance related to activity participation (please list)</LABEL> <TEXTAREA id=responses.8.L.description class=" visible" rows=4 cols=60 name="responses['8'].answers['L'].description"></TEXTAREA> </span> and on every other browser we tried, it renders as this <span class="field"> <input type="checkbox" name="responses['8'].answers['L'].code" id="responses.8.L" class="checkbox" value="L" onchange="showOtherBox( this, 'responses.8.L.description' )"> <label for="responses.8.L">Award(s) for special accomplishment or performance related to activity participation (please list)</label> <textarea rows="4" cols="60" name="responses['8'].answers['L'].description" id="responses.8.L.description" class="visible" classname="visible"></textarea> </span> The difference being that in the FTL script, the if statement [#if (answer.textLength > 0) && scripting] is true for everything except IE. In IE8 its false for some reason and therefore it does not put the OnChange javascript event on the input tag. Has anyone seen anything like this before? we are using Freemarker 2.3.9 Update, it kinda works if i turn compatibility mode on for IE8. but not exactly. when i do that, the onchange event doesn't fire until the check box loses focus. which is very different than everything else. Is there a quick way to fix this without too much trouble? i suppose i could put something in that says if ie8, insert onclick instead of onchange. that may work, but i would need an authorization from the client to fix it like that.

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  • â?? in my hmtl after purify

    - by mmcgrail
    I have a database the i am rebuilding the table structure was crap so I'm porting some of the data from one table to another. This data appears to have been copy past from MSO product so as I'm getting the data I clean it up with htmlpurifier and some alittle str_replace in php here the clean function function clean_html($html) { $config = HTMLPurifier_Config::createDefault(); $config->set('AutoFormat','RemoveEmpty',true); $config->set('HTML','AllowedAttributes','href,src'); $config->set('HTML','AllowedElements','p,em,strong,a,ul,li,ol,img'); $purifier = new HTMLPurifier($config); $html = $purifier->purify($html); $html = str_replace('&nbsp;',' ',$html); $html = str_replace("\r",'',$html); $html = str_replace("\n",'',$html); $html = str_replace("\t",'',$html); $html = str_replace(' ',' ',$html); $html = str_replace('<p> </p>','',$html); $html = str_replace(chr(160),' ',$html); return trim($html); } but when I put the results into my new table and out put them to the ckeditor I get those three characters. I then have a javascript function that is called to remove special characters from the content of the ckeditor too. it doesn't clean it either function remove_special(str) { var rExps=[ /[\xC0-\xC2]/g, /[\xE0-\xE2]/g, /[\xC8-\xCA]/g, /[\xE8-\xEB]/g, /[\xCC-\xCE]/g, /[\xEC-\xEE]/g, /[\xD2-\xD4]/g, /[\xF2-\xF4]/g, /[\xD9-\xDB]/g, /[\xF9-\xFB]/g, /\xD1/,/\xF1/g, "/[\u00a0|\u1680|[\u2000-\u2009]|u200a|\u200b|\u2028|\u2029|\u202f|\u205f|\u3000|\xa0]/g", /\u000b/g,'/[\u180e|\u000c]/g', /\u2013/g, /\u2014/g, /\xa9/g,/\xae/g,/\xb7/g,/\u2018/g,/\u2019/g,/\u201c/g,/\u201d/g,/\u2026/g]; var repChar=['A','a','E','e','I','i','O','o','U','u','N','n',' ','\t','','-','--','(c)','(r)','*',"'","'",'"','"','...']; for(var i=0; i<rExps.length; i++) { str=str.replace(rExps[i],repChar[i]); } for (var x = 0; x < str.length; x++) { charcode = str.charCodeAt(x); if ((charcode < 32 || charcode > 126) && charcode !=10 && charcode != 13) { str = str.replace(str.charAt(x), ""); } } return str; } Does anyone know off hand what I need to do to get rid of them. I think they may be some sort of quote

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  • Realtime MySQL search results on an advanced search page

    - by Andrew Heath
    I'm a hobbyist, and started learning PHP last September solely to build a hobby website that I had always wished and dreamed another more competent person might make. I enjoy programming, but I have little free time and enjoy a wide range of other interests and activities. I feel learning PHP alone can probably allow me to create 98% of the desired features for my site, but that last 2% is awfully appealing: The most powerful tool of the site is an advanced search page that picks through a 1000+ record game scenario database. Users can data-mine to tremendous depths - this advanced page has upwards of 50 different potential variables. It's designed to allow the hardcore user to search on almost any possible combination of data in our database and it works well. Those who aren't interested in wading through the sea of options may use the Basic Search, which is comprised of the most popular parts of the Advanced search. Because the advanced search is so comprehensive, and because the database is rather small (less than 1,200 potential hits maximum), with each variable you choose to include the likelihood of getting any qualifying results at all drops dramatically. In my fantasy land where I can wield AJAX as if it were Excalibur, my users would have a realtime Total Results counter in the corner of their screen as they used this page, which would automatically update its query structure and report how many results will be displayed with the addition of each variable. In this way it would be effortless to know just how many variables are enough, and when you've gone and added one that zeroes out the results set. A somewhat similar implementation, at least visually, would be the Subtotal sidebar when building a new custom computer on IBuyPower.com For those of you actually still reading this, my question is really rather simple: Given the time & ability constraints outlined above, would I be able to learn just enough AJAX (or whatever) needed to pull this one feature off without too much trouble? would I be able to more or less drop-in a pre-written code snippet and tweak to fit? or should I consider opening my code up to a trusted & capable individual in the future for this implementation? (assuming I can find one...) Thank you.

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  • 'Good' programming form in maintaining / updating / accessing files by entry

    - by zhermes
    Basic Question: If I'm storying/modifying data, should I access elements of a file by index hard-coded index, i.e. targetFile.getElement(5); via a hardcoded identifier (internally translated into index), i.e. target.getElementWithID("Desired Element"), or with some intermediate DESIRED_ELEMENT = 5; ... target.getElement(DESIRED_ELEMENT), etc. Background: My program (c++) stores data in lots of different 'dataFile's. I also keep a list of all of the data-files in another file---a 'listFile'---which also stores some of each one's properties (see below, but i.e. what it's name is, how many lines of information it has etc.). There is an object which manages the data files and the list file, call it a 'fileKeeper'. The entries of a listFile look something like: filename , contents name , number of lines , some more numbers ... Its definitely possible that I may add / remove fields from this list --- but in general, they'll stay static. Right now, I have a constant string array which holds the identification of each element in each entry, something like: const string fileKeeper::idKeys[] = { "FileName" , "Contents" , "NumLines" ... }; const int fileKeeper::idKeysNum = 6; // 6 - for example I'm trying to manage this stuff in 'good' programatic form. Thus, when I want to retrieve the number of lines in a file (for example), instead of having a method which just retrieves the '3'rd element... Instead I do something like: string desiredID = "NumLines"; int desiredIndex = indexForID(desiredID); string desiredElement = elementForIndex(desiredIndex); where the function indexForID() goes through the entries of idKeys until it finds desiredID then returns the index it corresponds to. And elementForIndex(index) actually goes into the listFile to retrieve the index'th element of the comma-delimited string. Problem: This still seems pretty ugly / poor-form. Is there a way I should be doing this? If not, what are some general ways in which this is usually done? Thanks!

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  • How do you return a string from a function correctly in Dynamic C?

    - by aquanar
    I have a program I am trying to debug, but Dynamic C apparently treats strings differently than normal C does (well, character arrays, anyway). I have a function that I made to make an 8 character long (well, 10 to include the \0 ) string of 0s and 1s to show me the contents of an 8-bit char variable. (IE, I give it the number 13, it returns the string "0001101\0" ) When I use the code below, it prints out !{happy face] 6 times (well, the second one is the happy face alone for some reason), each return comes back as 0xDEAE or "!\x02. I thought it would dereference it and return the appropriate string, but it appears to just be sending the pointer and attempting to parse it. This may seem silly, but my experience was actually in C++ and Java, so going back to C brings up a few issues that were dealt with in later programming languages that I'm not entirely sure how to deal with (like the lack of string variables). How could I fix this code, or how would be a better way to do what I am trying to do (I thought maybe sending in a pointer to a character array and working on it from the function might work, but I thought I should ask to see if maybe I'm just trying to reinvent the wheel). Currently I have it set up like this: this is an excerpt from the main() display[0] = '\0'; for(i=0;i<6;i++) { sprintf(s, "%s ", *char_to_bits(buffer[i])); strcat(display, s); } DispStr(8,5, display); and this is the offending function: char *char_to_bits(char x) { char bits[16]; strcpy(bits,"00000000\0"); if (x & 0x01) bits[7]='1'; if (x & 0x02) bits[6]='1'; if (x & 0x04) bits[5]='1'; if (x & 0x08) bits[4]='1'; if (x & 0x10) bits[3]='1'; if (x & 0x20) bits[2]='1'; if (x & 0x40) bits[1]='1'; if (x & 0x80) bits[0]='1'; return bits; } and just for the sake of completion, the other function is used to output to the stdio window at a specific location: void DispStr(int x, int y, char *s) { x += 0x20; y += 0x20; printf ("\x1B=%c%c%s", x, y, s); }

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  • Rails controller not rendering correct view when form is force-submitted by Javascript

    - by whazzmaster
    I'm using Rails with jQuery, and I'm working on a page for a simple site that prints each record to a table. The only editable field for each record is a checkbox. My goal is that every time a checkbox is changed, an ajax request updates that boolean attribute for the record (i.e., no submit button). My view code: <td> <% form_remote_tag :url => admin_update_path, :html => { :id => "form#{lead.id}" } do %> <%= hidden_field :lead, :id, :value => lead.id %> <%= check_box :lead, :contacted, :id => "checkbox"+lead.id.to_s, :checked => lead.contacted, :onchange => "$('#form#{lead.id}').submit();" %> <% end %> </td> In my routes.rb, admin_update_path is defined by map.admin_update 'update', :controller => "admin", :action => "update", :method => :post I also have an RJS template to render back an update. The contents of this file is currently just for testing (I just wanted to see if it worked, this will not be the ultimate functionality on a successful save)... page << "$('#checkbox#{@lead.id}').hide();" When clicked, the ajax request is successfully sent, with the correct params, and the action on the controller can retrieve the record and update it just fine. The problem is that it doesn't send back the JS; it changes the page in the browser and renders the generated Javascript as plain text rather than executing it in-place. Rails does some behind-the-scenes stuff to figure out if the incoming request is an ajax call, and I can't figure out why it's interpreting the incoming request as a regular web request as opposed to an ajax request. I may be missing something extremely simple here, but I've kind-of burned myself out looking so I thought I'd ask for another pair of eyes. Thanks in advance for any info!

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  • Can I use the [] operator in C++ to create virtual arrays

    - by Shane MacLaughlin
    I have a large code base, originally C ported to C++ many years ago, that is operating on a number of large arrays of spatial data. These arrays contain structs representing point and triangle entities that represent surface models. I need to refactor the code such that the specific way these entities are stored internally varies for specific scenarios. For example if the points lie on a regular flat grid, I don't need to store the X and Y coordinates, as they can be calculated on the fly, as can the triangles. Similarly, I want to take advantage of out of core tools such as STXXL for storage. The simplest way of doing this is replacing array access with put and get type functions, e.g. point[i].x = XV; becomes Point p = GetPoint(i); p.x = XV; PutPoint(i,p); As you can imagine, this is a very tedious refactor on a large code base, prone to all sorts of errors en route. What I'd like to do is write a class that mimics the array by overloading the [] operator. As the arrays already live on the heap, and move around with reallocs, the code already assumes that references into the array such as point *p = point + i; may not be used. Is this class feasible to write? For example writing the methods below in terms of the [] operator; void MyClass::PutPoint(int Index, Point p) { if (m_StorageStrategy == RegularGrid) { int xoffs,yoffs; ComputeGridFromIndex(Index,xoffs,yoffs); StoreGridPoint(xoffs,yoffs,p.z); } else m_PointArray[Index] = p; } } Point MyClass::GetPoint(int Index) { if (m_StorageStrategy == RegularGrid) { int xoffs,yoffs; ComputeGridFromIndex(Index,xoffs,yoffs); return GetGridPoint(xoffs,yoffs); // GetGridPoint returns Point } else return m_PointArray[Index]; } } My concern is that all the array classes I've seen tend to pass by reference, whereas I think I'll have to pass structs by value. I think it should work put other than performance, can anyone see any major pitfalls with this approach. n.b. the reason I have to pass by value is to get point[a].z = point[b].z + point[c].z to work correctly where the underlying storage type varies.

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  • Authenticating users in iPhone app

    - by Myron
    I'm developing an HTTP api for our web application. Initially, the primary consumer of the API will be an iPhone app we're developing, but I'm designing this with future uses in mind (such as mobile apps for other platforms). I'm trying to decide on the best way to authenticate users so they can access their accounts from the iPhone. I've got a design that I think works well, but I'm no security expert, so I figured it would be good to ask for feedback here. The design of the user authentication has 3 primary goals: Good user experience: We want to allow users to enter their credentials once, and remain logged in indefinitely, until they explicitly log out. I would have considered OAuth if not for the fact that the experience from an iPhone app is pretty awful, from what I've heard (i.e. it launches the login form in Safari, then tells the user to return to the app when authentication succeeds). No need to store the user creds with the app: I always hate the idea of having the user's password stored in either plain text or symmetrically encrypted anywhere, so I don't want the app to have to store the password to pass it to the API for future API requests. Security: We definitely don't need the intense security of a banking app, but I'd obviously like this to be secure. Overall, the API is REST-inspired (i.e. treating URLs as resources, and using the HTTP methods and status codes semantically). Each request to the API must include two custom HTTP headers: an API Key (unique to each client app) and a unique device ID. The API requires all requests to be made using HTTPS, so that the headers and body are encrypted. My plan is to have an api_sessions table in my database. It has a unique constraint on the API key and unique device ID (so that a device may only be logged into a single user account through a given app) as well as a foreign key to the users table. The API will have a login endpoint, which receives the username/password and, if they match an account, logs the user in, creating an api_sessions record for the given API key and device id. Future API requests will look up the api_session using the API key and device id, and, if a record is found, treat the request as being logged in under the user account referenced by the api_session record. There will also be a logout API endpoint, which deletes the record from the api_sessions table. Does anyone see any obvious security holes in this?

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  • Sorting a list of numbers with modified cost

    - by David
    First, this was one of the four problems we had to solve in a project last year and I couldn’t find a suitable algorithm so we handle in a brute force solution. Problem: The numbers are in a list that is not sorted and supports only one type of operation. The operation is defined as follows: Given a position i and a position j the operation moves the number at position i to position j without altering the relative order of the other numbers. If i j, the positions of the numbers between positions j and i - 1 increment by 1, otherwise if i < j the positions of the numbers between positions i+1 and j decreases by 1. This operation requires i steps to find a number to move and j steps to locate the position to which you want to move it. Then the number of steps required to move a number of position i to position j is i+j. We need to design an algorithm that given a list of numbers, determine the optimal (in terms of cost) sequence of moves to rearrange the sequence. Attempts: Part of our investigation was around NP-Completeness, we make it a decision problem and try to find a suitable transformation to any of the problems listed in Garey and Johnson’s book: Computers and Intractability with no results. There is also no direct reference (from our point of view) to this kind of variation in Donald E. Knuth’s book: The art of Computer Programing Vol. 3 Sorting and Searching. We also analyzed algorithms to sort linked lists but none of them gives a good idea to find de optimal sequence of movements. Note that the idea is not to find an algorithm that orders the sequence, but one to tell me the optimal sequence of movements in terms of cost that organizes the sequence, you can make a copy and sort it to analyze the final position of the elements if you want, in fact we may assume that the list contains the numbers from 1 to n, so we know where we want to put each number, we are just concerned with minimizing the total cost of the steps. We tested several greedy approaches but all of them failed, divide and conquer sorting algorithms can’t be used because they swap with no cost portions of the list and our dynamic programing approaches had to consider many cases. The brute force recursive algorithm takes all the possible combinations of movements from i to j and then again all the possible moments of the rest of the element’s, at the end it returns the sequence with less total cost that sorted the list, as you can imagine the cost of this algorithm is brutal and makes it impracticable for more than 8 elements. Our observations: n movements is not necessarily cheaper than n+1 movements (unlike swaps in arrays that are O(1)). There are basically two ways of moving one element from position i to j: one is to move it directly and the other is to move other elements around i in a way that it reaches the position j. At most you make n-1 movements (the untouched element reaches its position alone). If it is the optimal sequence of movements then you didn’t move the same element twice.

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  • My store returns no code id and breaks 404 error. Magento

    - by numerical25
    I know what the issue is but I dont know how to fix it. I just migrated my magento store locally and I guess possibly some data may have been lost when transferring the DB. the DB is very large. Anyhow, when I login to my admin page, I get a 404 error, page was not found. I debugged the issue and got down to the wire. The exception is thrown in Mage/Core/Model/App.php. Line 759 to be exacted. The following is a snippet. Mage/Core/Model/App.php if (empty($this->_stores[$id])) { $store = Mage::getModel('core/store'); /* @var $store Mage_Core_Model_Store */ if (is_numeric($id)) { $store->load($id); // THIS ID IS FROM Mage_Core_Model_App::ADMIN_STORE_ID and its empty which causes the error } elseif (is_string($id)) { $store->load($id, 'code'); } if (!$store->getCode()) { // RETURNS FALSE HERE BECAUSE NO ID Specified $this->throwStoreException(); } $this->_stores[$store->getStoreId()] = $store; $this->_stores[$store->getCode()] = $store; } The store returns null because $id is null so it therefore does not load any model which explains why it returns false when calling getCode() [EDIT] If you want clarification, please ask for more before voting my post down. Remember I am still trying to get help not get neglected. I am using Version 1.4.1.1. When I type in the URL for admin, I get a 404 page. I walked through the code thouroughly and found that the Model MAGE_CORE_MODEL_STORE::getCode(); Returns Null which triggers the exception. and ends the script. I do not have any other detail. I further troubleshooted the issue by checking the database and that is what the screen shot is. Showing that there is infact data in the Code Colunn. So my question is why is the Model returning a empty column when the column clearly has a value. What can I do to further troubleshoot and figure out why its not working [EDIT UPDATE NEW] I did some research. the reason its returning NULL is because the store ID is null being passed Mage::getStoreConfigFlag('web/secure/use_in_adminhtml', Mage_Core_Model_App::ADMIN_STORE_ID); // THIS IS THE ID being specified Mage_Core_Model_App::ADMIN_STORE_ID has no value in it, so this method throws the exception. Not sure why how to fix this.

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  • Unable to get Stencil Buffer to work in iOS 4+ (5.0 works fine). [OpenGL ES 2.0]

    - by MurderDev
    So I am trying to use a stencil buffer in iOS for masking/clipping purposes. Do you guys have any idea why this code may not work? This is everything I have associated with Stencils. On iOS 4 I get a black screen. On iOS 5 I get exactly what I expect. The transparent areas of the image I drew in the stencil are the only areas being drawn later. Code is below. This is where I setup the frameBuffer, depth and stencil. In iOS the depth and stencil are combined. -(void)setupDepthBuffer { glGenRenderbuffers(1, &depthRenderBuffer); glBindRenderbuffer(GL_RENDERBUFFER, depthRenderBuffer); glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8_OES, self.frame.size.width * [[UIScreen mainScreen] scale], self.frame.size.height * [[UIScreen mainScreen] scale]); } -(void)setupFrameBuffer { glGenFramebuffers(1, &frameBuffer); glBindFramebuffer(GL_FRAMEBUFFER, frameBuffer); glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, colorRenderBuffer); glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthRenderBuffer); glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, depthRenderBuffer); // Check the FBO. if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) { NSLog(@"Failure with framebuffer generation: %d", glCheckFramebufferStatus(GL_FRAMEBUFFER)); } } This is how I am setting up and drawing the stencil. (Shader code below.) glEnable(GL_STENCIL_TEST); glDisable(GL_DEPTH_TEST); glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE); glDepthMask(GL_FALSE); glStencilFunc(GL_ALWAYS, 1, -1); glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE); glColorMask(0, 0, 0, 0); glClear(GL_STENCIL_BUFFER_BIT); machineForeground.shader = [StencilEffect sharedInstance]; [machineForeground draw]; machineForeground.shader = [BasicEffect sharedInstance]; glDisable(GL_STENCIL_TEST); glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE); glDepthMask(GL_TRUE); Here is where I am using the stencil. glEnable(GL_STENCIL_TEST); glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP); glStencilFunc(GL_EQUAL, 1, -1); ...Draw Stuff here glDisable(GL_STENCIL_TEST); Finally here is my fragment shader. varying lowp vec2 TexCoordOut; uniform sampler2D Texture; void main(void) { lowp vec4 color = texture2D(Texture, TexCoordOut); if(color.a < 0.1) gl_FragColor = color; else discard; }

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  • capistrano initial deployment

    - by Richard G
    I'm trying to set up Capistrano to deploy to an AWS box. This is the first time I've tried to set this up, so please bear with me. Could someone take a look at this and let me know if you can solve this error? The output below is the deploy.rb file, and it's output when it runs. set :application, "apparel1" set :repository, "git://github.com/rgilling/GroceryRun.git" set :scm, :git set :user, "ubuntu" set :scm_passphrase, "pre5ence" # Or: `accurev`, `bzr`, `cvs`, `darcs`, `git`, `mercurial`, `perforce`, `subversion` or `none` ssh_options[:keys] = ["/Users/rgilling/Documents/Projects/Apparel1/abesakey.pem"] ssh_options[:forward_agent] = true set :location, "ec2-107-22-27-42.compute-1.amazonaws.com" role :web, location # Your HTTP server, Apache/etc role :app, location # This may be the same as your `Web` server role :db, location, :primary => true # This is where Rails migrations will run set :deploy_to, "/var/www/#{application}" set :deploy_via, :remote_cache set :use_sudo, true # if you want to clean up old releases on each deploy uncomment this: # after "deploy:restart", "deploy:cleanup" # if you're still using the script/reaper helper you will need # these http://github.com/rails/irs_process_scripts # If you are using Passenger mod_rails uncomment this: namespace :deploy do task :start do ; end task :stop do ; end task :restart, :roles => :app, :except => { :no_release => true } do run "#{try_sudo} touch #{File.join(current_path,'tmp','restart.txt')}" end end Then the execution results in this permission error. I think I"ve set up the SSH etc. correctly... updating the cached checkout on all servers executing locally: "git ls-remote git://github.com/rgilling/GroceryRun.git HEAD" command finished in 1294ms * executing "if [ -d /var/www/apparel1/shared/cached-copy ]; then cd /var/www/apparel1/shared/cached-copy && git fetch -q origin && git fetch --tags -q origin && git reset -q --hard f35dc5868b52649eea86816d536d5db8c915856e && git clean -q -d -x -f; else git clone -q git://github.com/rgilling/GroceryRun.git /var/www/apparel1/shared/cached-copy && cd /var/www/apparel1/shared/cached-copy && git checkout -q -b deploy f35dc5868b52649eea86816d536d5db8c915856e; fi" servers: ["ec2-107-22-27-42.compute-1.amazonaws.com"] [ec2-107-22-27-42.compute-1.amazonaws.com] executing command ** **[ec2-107-22-27-42.compute-1.amazonaws.com :: err] error: cannot open .git/FETCH_HEAD: Permission denied**

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  • Getting caught in loops - R

    - by user334898
    I am looking at whether or not certain 'systems' for betting really do work as claimed, namely, that they have a positive expectation. One such system is based on the rebate on loss. You basically have a large master pot, say $1 million. Your bankroll for each game is $50k. The way it works, is as follows: 1) Start with $50k, always bet on banker 2) If you win, add the money to the master pot. Then play again with $50k. 3) If you lose(now you're at $30k) play till you either: (a) hit 0, you get a rebate of 10%. Begin playing again with $50k+5k=$55k. (b) If you win more than the initial bankroll, add the money to the master pot. Then play again with $50k. 4) Continue until you double the master pot. I just cant find an easy way of programming out the possible cases in R, since you can eventually go down an improbable path. For example, you start at 50k, lose 20, win 19, now you're at 49, now you lose 20, lose 20, now youre at 9, you either lose 9 and get back 5k or you win and this cycle continues until you either end up with more than 50k or hit 0 and get the rebate on the 50k and start again with $50k +5k. Here's some code i started, but i havent figured out a good way of handling the cases where you get stuck and keeping track of the number of games played. Thanks again for your help. Obviously, I understand you may be busy and not have time. p.loss <- .4462466 p.win <- .4585974 p.tie <- 1 - (p.win+p.loss) prob <- c(p.win,p.tie,p.loss) bet<-20 x <- c(19,0,-20) r <- 10 # rebate = 20% br.i <- 50 br<-200 #for(i in 1:100){ # cbr.i<-0 y <- sample(x,1,replace=T,prob) cbr.i<-y+br.i if(cbr.i > br.i){ br<-br+(cbr.i-br.i); cbr.i<-br.i; }else{ y <- sample(x,2,replace=T,prob); if( sum(y)< cbr.i ){ cbr.i<-br.i+(1/r)*br.i; br<-br-br.i} cbr.i<-y+ }else{ cbr.i<- sum(y) + cbr.i; }if(cbr.i <= bet){ y <- sample(x,1,replace=T,prob) if(abs(y)>cbr.i){ cbr.i<-br.i+(1/r)*br.i } }

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  • Is typeid of type name always evaluated at compile time in c++ ?

    - by cyril42e
    I wanted to check that typeid is evaluated at compile time when used with a type name (ie typeid(int), typeid(std::string)...). To do so, I repeated in a loop the comparison of two typeid calls, and compiled it with optimizations enabled, in order to see if the compiler simplified the loop (by looking at the execution time which is 1us when it simplifies instead of 160ms when it does not). And I get strange results, because sometimes the compiler simplifies the code, and sometimes it does not. I use g++ (I tried different 4.x versions), and here is the program: #include <iostream> #include <typeinfo> #include <time.h> class DisplayData {}; class RobotDisplay: public DisplayData {}; class SensorDisplay: public DisplayData {}; class RobotQt {}; class SensorQt {}; timespec tp1, tp2; const int n = 1000000000; int main() { int avg = 0; clock_gettime(CLOCK_REALTIME, &tp1); for(int i = 0; i < n; ++i) { // if (typeid(RobotQt) == typeid(RobotDisplay)) // (1) compile time // if (typeid(SensorQt) == typeid(SensorDisplay)) // (2) compile time if (typeid(RobotQt) == typeid(RobotDisplay) || typeid(SensorQt) == typeid(SensorDisplay)) // (3) not compile time ???!!! avg++; else avg--; } clock_gettime(CLOCK_REALTIME, &tp2); std::cout << "time (" << avg << "): " << (tp2.tv_sec-tp1.tv_sec)*1000000000+(tp2.tv_nsec-tp1.tv_nsec) << " ns" << std::endl; } The conditions in which this problem appear are not clear, but: - if there is no inheritance involved, no problem (always compile time) - if I do only one comparison, no problem - the problem only appears only with a disjunction of comparisons if all the terms are false So is there something I didn't get with how typeid works (is it always supposed to be evaluated at compilation time when used with type names?) or may this be a gcc bug in evaluation or optimization? About the context, I tracked down the problem to this very simplified example, but my goal is to use typeid with template types (as partial function template specialization is not possible). Thanks for your help!

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  • Exception from Response.Redirect?

    - by allencoded
    I keep getting an error: A first chance exception of type 'System.Threading.ThreadAbortException' occurred in mscorlib.dll An exception of type 'System.Threading.ThreadAbortException' occurred in mscorlib.dll but was not handled in user code The thread '' (0x27ee4) has exited with code 0 (0x0). I was told it was related to this: protected void Button1_Click(object sender, EventArgs e) { Response.Redirect("Results.aspx?Keywords=" + searchString.Text); } I figured it may help to include my complete code. The code above is the only C# code on my first asp page. That code relates to this code on this page. It is also the only C# code I have on my second page. I am simply just trying to pass a keyword from a search form to this block of code: if (Request.QueryString["Keywords"] != null){ string keywords = Request.QueryString["Keywords"]; string myAppID = "HIDDEN"; var xml = XDocument.Load("http://svcs.ebay.com/services/search/FindingService/v1?OPERATION-NAME=findItemsByKeywords&SERVICE-VERSION=1.0.0&SECURITY-APPNAME=" + myAppID + "&RESPONSE-DATA-FORMAT=XML&REST-PAYLOAD&keywords=" + keywords + "&paginationInput.entriesPerPage=5"); XNamespace ns = "http://www.ebay.com/marketplace/search/v1/services"; var titles = from item in xml.Root.Descendants(ns + "title") select new{ title = xml.Descendants(ns + "title").Select (x => x.Value), }; foreach (var item in titles){ Label1.Text += item; } } This block of code calls the keyword value and uses it in an api to perform a search. The code of the xml(api) formats like this: <findItemsByKeywordsResponse xmlns="http://www.ebay.com/marketplace/search/v1/services"> <searchReslut count="5"> <item> <title></title> </item> <item> <title></title> </item> <item> <title></title> </item> Why am I getting this error how do you fix it?

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  • CSS: right wrapper dropping off the end of the page

    - by user310606
    I have an issue with a site I am working on where the right wrapper keeps dropping down below the site. Obviously I want it to stay on the right hand side. I've coded up a test case which shows my issue (I think) and I'm wondering if there is a better way to do things. The website url is http://www.musicworkshop.co.nz/ Below is the test case which (I think) is the cause of my issue, however it may not be. The pink box drops down if it does not fit within the page width. Is there a better way to do this? John <html> <head> <title> Test page </title> <link rel="stylesheet" href="test.css" type="text/css" /> </head> <body> <div id="superbox"> <div id="box1"> </div> <div id="box2"> </div> <div id="box3"> </div> <div id="box4"> </div> <div id="box5"> </div> <div id="box6"> </div> </div> </body> </html> #outsidebox{ width: 100%; } #superbox{ width: 1000px; height: 100px; margin: 0 auto; } #box1{ height: 100px; width: 200px; background: red; float: left; } #box2{ height: 100px; width: 200px; background: yellow; float: left; } #box3{ height: 100px; width: 200px; background: blue; float: left; } #box4{ height: 100px; width: 200px; background: green; float: left; } #box5{ height: 100px; width: 200px; background: grey; float: left; } #box6{ height: 100px; width: 200px; background: pink; float: left; }

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  • Delete duplicate rows, do not preserve one row

    - by Radley
    I need a query that goes through each entry in a database, checks if a single value is duplicated elsewhere in the database, and if it is - deletes both entries (or all, if more than two). Problem is the entries are URLs, up to 255 characters, with no way of identifying the row. Some existing answers on Stackoverflow do not work for me due to performance limitations, or they use uniqueid which obviously won't work when dealing with a string. Long Version: I have two databases containing URLs (and only URLs). One database has around 3,000 urls and the other around 1,000. However, a large majority of the 1,000 urls were taken from the 3,000 url database. I need to merge the 1,000 into the 3,000 as new entries only. For this, I made a third database with combined URLs from both tables, about 4,000 entries. I need to find all duplicate entries in this database and delete them (Both of them, without leaving either). I have followed the query of a few examples on this site, but whenever I try to delete both entries it ends up deleting all the entries, or giving sql errors. Alternatively: I have two databases, each containing the separate database. I need to check each row from one database against the other to find any that aren't duplicates, and then add those to a third database. Edit: I've got my own PHP solution which is pretty hacky, but works. I cannot answer my own question for 8 hours because I'm new, so here it is for now: I went with a PHP script to accomplish this, as I'm more familiar with PHP than MySQL. This generates a simple list of urls that only exist in the target database, but not both. If you have more than 7,000 entries to parse this may take awhile, and you will need to copy/paste the results into a text file or expand the script to store them back into a database. I'm just doing it manually to save time. Note: Uses MeekroDB <pre> <?php require('meekrodb.2.1.class.php'); DB::$user = 'root'; DB::$password = ''; DB::$dbName = 'testdb'; $all = DB::query('SELECT * FROM old_urls LIMIT 7000'); foreach($all as $row) { $test = DB::query('SELECT url FROM new_urls WHERE url=%s', $row['url']); if (!is_array($test)) { echo $row['url'] . "\n"; }else{ if (count($test) == 0) { echo $row['url'] . "\n"; } } } ?> </pre>

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  • getting service from wsdd via xpath not wroking (xmltask)

    - by subes
    Hi, I am trying to get the XPath "/deployment/service". Tested on this site: http://www.xmlme.com/XpathTool.aspx <?xml version="1.0" encoding="UTF-8" standalone="no"?> <deployment xmlns="http://xml.apache.org/axis/wsdd/" xmlns:java="http://xml.apache.org /axis/wsdd/providers/java"> <service name="kontowebservice" provider="java:RPC" style="rpc" use="literal"> <parameter name="wsdlTargetNamespace" value="http://strategies.spine"/> <parameter name="wsdlServiceElement" value="ExposerService"/> <parameter name="wsdlServicePort" value="kontowebservice"/> <parameter name="className" value="dmd4biz.container.webservice.konto.internal.KontoWebServiceImpl_WS"/> <parameter name="wsdlPortType" value="Exposer"/> <parameter name="typeMappingVersion" value="1.2"/> <operation xmlns:operNS="http://strategies.spine" xmlns:rtns="http://www.w3.org/2001/XMLSchema" name="expose" qname="operNS:expose" returnQName="exposeReturn" returnType="rtns:anyType" soapAction=""> <parameter xmlns:tns="http://www.w3.org/2001/XMLSchema" qname="in0" type="tns:anyType"/> </operation> <parameter name="allowedMethods" value="expose"/> <parameter name="scope" value="Request"/> </service> </deployment> I absolutely can't find out why it always tells me that my xpath does not match... This may be stupid, but am I missing something? EDIT Thanks to the answer from Dimitre Novatchev I was able to find a workaround: <xmltask failwithoutmatch="true" report="false"> <fileset dir="${src.gen}/" includes="**/*-deploy.wsdd" /> <copy path="//*[local-name()='service']" buffer="tmpServiceBuf" append="true" /> </xmltask> <xmltask failwithoutmatch="true" report="false" source="${basedir}/env/axis/WEB-INF/server-config.wsdd" dest="${build.stage}/resources/WEB-INF/server-config.wsdd"> <insert path="//*[local-name()='transport'][last()]" buffer="tmpServiceBuf" position="after" /> </xmltask> Binding namespaces with xmltask (which is the tool that gave me the headaches) seems not to be possible. The code above did the trick.

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  • Is 4-5 years the “Midlife Crisis” for a programming career?

    - by Jeffrey
    I’ve been programming C# professionally for a bit over 4 years now. For the past 4 years I’ve worked for a few small/medium companies ranging from “web/ads agencies”, small industry specific software shops to a small startup. I've been mainly doing "business apps" that involves using high-level programming languages (garbage collected) and my overall experience was that all of the works I’ve done could have been more professional. A lot of the things were done incorrectly (in a rush) mainly due to cost factor that people always wanted something “now” and with the smallest amount of spendable money. I kept on thinking maybe if I could work for a bigger companies or a company that’s better suited for programmers, or somewhere that's got the money and time to really build something longer term and more maintainable I may have enjoyed more in my career. I’ve never had a “mentor” that guided me through my 4 years career. I am pretty much blog / google / self taught programmer other than my bachelor IT degree. I’ve also observed another issue that most so called “senior” programmer in “my working environment” are really not that senior skill wise. They are “senior” only because they’ve been a long time programmer, but the code they write or the decisions they make are absolutely rubbish! They don't want to learn, they don't want to be better they just want to get paid and do what they've told to do which make sense and most of us are like that. Maybe that’s why they are where they are now. But I don’t want to become like them I want to be better. I’ve run into a mental state that I no longer intend to be a programmer for my future career. I started to think maybe there are better things out there to work on. The more blogs I read, the more “best practices” I’ve tried the more I feel I am drifting away from “my reality”. But I am not a great programmer otherwise I don't think I am where I am now. I think 4-5 years is a stage that can be a step forward career wise or a step out of where you are. I just wanted to hear what other have to say about what I’ve mentioned above and whether you’ve experienced similar situation in your past programming career and how you dealt with it. Thanks.

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  • How do I mock/fake/replace/stub a base class at unit-test time in C#?

    - by MatthewMartin
    UPDATE: I've changed the wording of the question. Previously it was a yes/no question about if a base class could be changed at runtime. I may be working on mission impossible here, but I seem to be getting close. I want to extend a ASP.NET control, and I want my code to be unit testable. Also, I'd like to be able to fake behaviors of a real Label (namely things like ID generation, etc), which a real Label can't do in an nUnit host. Here a working example that makes assertions on something that depends on a real base class and something that doesn't-- in a more realistic unit test, the test would depend on both --i.e. an ID existing and some custom behavior. Anyhow the code says it better than I can: public class LabelWrapper : Label //Runtime //public class LabelWrapper : FakeLabel //Unit Test time { private readonly LabelLogic logic= new LabelLogic(); public override string Text { get { return logic.ProcessGetText(base.Text); } set { base.Text=logic.ProcessSetText(value); } } } //Ugh, now I have to test FakeLabelWrapper public class FakeLabelWrapper : FakeLabel //Unit Test time { private readonly LabelLogic logic= new LabelLogic(); public override string Text { get { return logic.ProcessGetText(base.Text); } set { base.Text=logic.ProcessSetText(value); } } } [TestFixture] public class UnitTest { [Test] public void Test() { //Wish this was LabelWrapper label = new LabelWrapper(new FakeBase()) LabelWrapper label = new LabelWrapper(); //FakeLabelWrapper label = new FakeLabelWrapper(); label.Text = "ToUpper"; Assert.AreEqual("TOUPPER",label.Text); StringWriter stringWriter = new StringWriter(); HtmlTextWriter writer = new HtmlTextWriter(stringWriter); label.RenderControl(writer); Assert.AreEqual(1,label.ID); Assert.AreEqual("<span>TOUPPER</span>", stringWriter.ToString()); } } public class FakeLabel { virtual public string Text { get; set; } public void RenderControl(TextWriter writer) { writer.Write("<span>" + Text + "</span>"); } } //System Under Test internal class LabelLogic { internal string ProcessGetText(string value) { return value.ToUpper(); } internal string ProcessSetText(string value) { return value.ToUpper(); } }

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  • Is there anything wrong with having a few private methods exposing IQueryable<T> and all public meth

    - by Nate Bross
    I'm wondering if there is a better way to approach this problem. The objective is to reuse code. Let’s say that I have a Linq-To-SQL datacontext and I've written a "repository style" class that wraps up a lot of the methods I need and exposes IQueryables. (so far, no problem). Now, I'm building a service layer to sit on top of this repository, many of the service methods will be 1<-1 with repository methods, but some will not. I think a code sample will illustrate this better than words. public class ServiceLayer { MyClassDataContext context; IMyRepository rpo; public ServiceLayer(MyClassDataContext ctx) { context = ctx; rpo = new MyRepository(context); } private IQueryable<MyClass> ReadAllMyClass() { // pretend there is some complex business logic here // and maybe some filtering of the current users access to "all" // that I don't want to repeat in all of the public methods that access // MyClass objects. return rpo.ReadAllMyClass(); } public IEnumerable<MyClass> GetAllMyClass() { // call private IQueryable so we can do attional "in-database" processing return this.ReadAllMyClass(); } public IEnumerable<MyClass> GetActiveMyClass() { // call private IQueryable so we can do attional "in-database" processing // in this case a .Where() clause return this.ReadAllMyClass().Where(mc => mc.IsActive.Equals(true)); } #region "Something my class MAY need to do in the future" private IQueryable<MyOtherTable> ReadAllMyOtherTable() { // there could be additional constrains which define // "all" for the current user return context.MyOtherTable; } public IEnumerable<MyOtherTable> GetAllMyOtherTable() { return this.ReadAllMyOtherTable(); } public IEnumerable<MyOtherTable> GetInactiveOtherTable() { return this.ReadAllMyOtherTable.Where(ot => ot.IsActive.Equals(false)); } #endregion } This particular case is not the best illustration, since I could just call the repository directly in the GetActiveMyClass method, but let’s presume that my private IQueryable does some extra processing and business logic that I don't want to replicate in both of my public methods. Is that a bad way to attack an issue like this? I don't see it being so complex that it really warrants building a third class to sit between the repository and the service class, but I'd like to get your thoughts. For the sake of argument, lets presume two additional things. This service is going to be exposed through WCF and that each of these public IEnumerable methods will be calling a .Select(m => m.ToViewModel()) on each returned collection which will convert it to a POCO for serialization. The service will eventually need to expose some context.SomeOtherTable which wont be wrapped into the repository.

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