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  • Multiple Table Inheritance vs. Single Table Inheritance in Ruby on Rails

    - by Tony
    I have been struggling for the past few hours thinking about which route I should go. I have a Notification model. Up until now I have used a notification_type column to manage the types but I think it will be better to create separate classes for the types of notifications as they behave differently. Right now, there are 3 ways notifications can get sent out: SMS, Twitter, Email Each notification would have: id subject message valediction sent_people_count deliver_by geotarget event_id list_id processed_at deleted_at created_at updated_at Seems like STI is a good candidate right? Of course Twitter/SMS won't have a subject and Twitter won't have a sent_people_count, valediction. I would say in this case they share most of their fields. However what if I add a "reply_to" field for twitter and a boolean for DM? My point here is that right now STI makes sense but is this a case where I may be kicking myself in the future for not just starting with MTI? To further complicate things, I want a Newsletter model which is sort of a notification but the difference is that it won't use event_id or deliver_by. I could see all subclasses of notification using about 2/3 of the notification base class fields. Is STI a no-brainer, or should I use MTI? Thanks!

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  • How to restrict access to a class's data based on state?

    - by Marcus Swope
    In an ETL application I am working on, we have three basic processes: Validate and parse an XML file of customer information from a third party Match values received in the file to values in our system Load customer data in our system The issue here is that we may need to display the customer information from any or all of the above states to an internal user and there is data in our customer class that will never be populated before the values have been matched in our system (step 2). For this reason, I would like to have the values not even be available to be accessed when the customer is in this state, and I would like to have to avoid some repeated logic everywhere like: if (customer.IsMatched) DisplayTextOnWeb(customer.SomeMatchedValue); My first thought for this was to add a couple interfaces on top of Customer that would only expose the properties and behaviors of the current state, and then only deal with those interfaces. The problem with this approach is that there seems to be no good way to move from an ICustomerWithNoMatchedValues to an ICustomerWithMatchedValues without doing direct casts, etc... (or at least I can't find one). I can't be the first to have come across this, how do you normally approach this? As a last caveat, I would like for this solution to play nice with FluentNHibernate :) Thanks in advance...

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  • jqGrid : "All in One" approach width jqGridEdit Class > how to set a composite primary key ?

    - by Qualliarys
    Hello, How to set a composite primary key for a "All in One" approach (grid defined in JS file, and data using jqGridEdit Class in php file) ? Please, for me a composite primary key of a table T, is a elementary primary key that is defined with some fields belong to this table T ! Here is my test, but i get no data and cannot use the CRUD operations : In my JS file i have this lines code: ... colModel":[ {"name":"index","index":"index","label":"index"}, // <= THAT'S JUST THE INDEX OF MY TABLE {"name":"user","index":"user","label":"user","key":true}, // <= A PART OF MY COMPOSITE PRIMARY KEY {"name":"pwd","index":"pwd","label":"pwd","key":true}, // <= A PART OF MY COMPOSITE PRIMARY KEY {"name":"state","index":"state","label":"state","key":true}, // <= A PART OF MY COMPOSITE PRIMARY KEY ... <= AND SO ON "url":"mygrid_crud.php", "datatype":"json", "jsonReader":{repeatitems:false}, "editurl": "mygrid_crud.php", "prmNames":{"id":"index"} // <= WHAT I NEED TO WRITE HERE ??? ... In my php file (mygrid_crud.php) : ... $grid = new jqGridEdit($conn); $query = "SELECT * FROM mytable WHERE user='$user' and pwd='$pwd' and state='$state'..."; // <= SELECT * it's ok or i need to specify all fields i need ? $grid->SelectCommand = $query; $grid->dataType = "json"; $grid->table = 'mytable'; $grid->setPrimaryKeyId('index'); // <= WHAT I NEED TO WRITE HERE ??? ... $grid->editGrid(); Please, say me what is wrong, and how to do to set a composite primary key in this approach !? Thank you so much for tour responses.

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  • Save object states in .data or attr - Performance vs CSS?

    - by Neysor
    In response to my answer yesterday about rotating an Image, Jamund told me to use .data() instead of .attr() First I thought that he is right, but then I thought about a bigger context... Is it always better to use .data() instead of .attr()? I looked in some other posts like what-is-better-data-or-attr or jquery-data-vs-attrdata The answers were not satisfactory for me... So I moved on and edited the example by adding CSS. I thought it might be useful to make a different Style on each image if it rotates. My style was the following: .rp[data-rotate="0"] { border:10px solid #FF0000; } .rp[data-rotate="90"] { border:10px solid #00FF00; } .rp[data-rotate="180"] { border:10px solid #0000FF; } .rp[data-rotate="270"] { border:10px solid #00FF00; } Because design and coding are often separated, it could be a nice feature to handle this in CSS instead of adding this functionality into JavaScript. Also in my case the data-rotate is like a special state which the image currently has. So in my opinion it make sense to represent it within the DOM. I also thought this could be a case where it is much better to save with .attr() then with .data(). Never mentioned before in one of the posts I read. But then i thought about performance. Which function is faster? I built my own test following: <!DOCTYPE HTML> <html> <head> <title>test</title> <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script> <script type="text/javascript"> function runfirst(dobj,dname){ console.log("runfirst "+dname); console.time(dname+"-attr"); for(i=0;i<10000;i++){ dobj.attr("data-test","a"+i); } console.timeEnd(dname+"-attr"); console.time(dname+"-data"); for(i=0;i<10000;i++){ dobj.data("data-test","a"+i); } console.timeEnd(dname+"-data"); } function runlast(dobj,dname){ console.log("runlast "+dname); console.time(dname+"-data"); for(i=0;i<10000;i++){ dobj.data("data-test","a"+i); } console.timeEnd(dname+"-data"); console.time(dname+"-attr"); for(i=0;i<10000;i++){ dobj.attr("data-test","a"+i); } console.timeEnd(dname+"-attr"); } $().ready(function() { runfirst($("#rp4"),"#rp4"); runfirst($("#rp3"),"#rp3"); runlast($("#rp2"),"#rp2"); runlast($("#rp1"),"#rp1"); }); </script> </head> <body> <div id="rp1">Testdiv 1</div> <div id="rp2" data-test="1">Testdiv 2</div> <div id="rp3">Testdiv 3</div> <div id="rp4" data-test="1">Testdiv 4</div> </body> </html> It should also show if there is a difference with a predefined data-test or not. One result was this: runfirst #rp4 #rp4-attr: 515ms #rp4-data: 268ms runfirst #rp3 #rp3-attr: 505ms #rp3-data: 264ms runlast #rp2 #rp2-data: 260ms #rp2-attr: 521ms runlast #rp1 #rp1-data: 284ms #rp1-attr: 525ms So the .attr() function did always need more time than the .data() function. This is an argument for .data() I thought. Because performance is always an argument! Then I wanted to post my results here with some questions, and in the act of writing I compared with the questions Stack Overflow showed me (similar titles) And true enough, there was one interesting post about performance I read it and run their example. And now I am confused! This test showed that .data() is slower then .attr() !?!! Why is that so? First I thought it is because of a different jQuery library so I edited it and saved the new one. But the result wasn't changing... So now my questions to you: Why are there some differences in the performance in these two examples? Would you prefer to use data- HTML5 attributes instead of data, if it represents a state? Although it wouldn't be needed at the time of coding? Why - Why not? Now depending on the performance: Would performance be an argument for you using .attr() instead of data, if it shows that .attr() is better? Although data is meant to be used for .data()? UPDATE 1: I did see that without overhead .data() is much faster. Misinterpreted the data :) But I'm more interested in my second question. :) Would you prefer to use data- HTML5 attributes instead of data, if it represents a state? Although it wouldn't be needed at the time of coding? Why - Why not? Are there some other reasons you can think of, to use .attr() and not .data()? e.g. interoperability? because .data() is jquery style and HTML Attributes can be read by all... UPDATE 2: As we see from T.J Crowder's speed test in his answer attr is much faster then data! which is again confusing me :) But please! Performance is an argument, but not the highest! So give answers to my other questions please too!

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  • Symfony: How to hide form fields from display and then set values for them in the action class

    - by Tom
    I am fairly new to symfony and I have 2 fields relating to my table "Pages"; created_by and updated_by. These are related to the users table (sfGuardUser) as foreign keys. I want these to be hidden from the edit/new forms so I have set up the generator.yml file to not display these fields: form: display: General: [name, template_id] Meta: [meta_title, meta_description, meta_keywords] Now I need to set the fields on the save. I have been searching for how to do this all day and tried a hundred methods. The method I have got working is this, in the actions class: protected function processForm(sfWebRequest $request, sfForm $form) { $form_params = $request->getParameter($form->getName()); $form_params['updated_by'] = $this->getUser()->getGuardUser()->getId(); if ($form->getObject()->isNew()) $form_params['created_by'] = $this->getUser()->getGuardUser()->getId(); $form->bind($form_params, $request->getFiles($form->getName())); So this works. But I get the feeling that ideally I shouldnt be modifying the web request, but instead modifying the form/object directly. However I havent had any success with things like: $form->getObject()->setUpdatedBy($this->getUser()->getGuardUser()); If anyone could offer any advice on the best ways about solving this type of problem I would be very grateful. Thanks, Tom

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  • Can I automatically throw descriptive exceptions with parameter values and class feild information?

    - by Robert H.
    I honestly don't throw exceptions often. I catch them even less, ironically. I currently work in shop where we let them bubble up to avicode. For whatever reason, however, avicode isn't configured to capture some of the critical bits I need when these exceptions come bouncing back to my attention. Specifically, I'd like to see the parameter values and the class’s field data at the time of the exception. I’d guess with the large suite of .Net services that I could create a static method to crawl up the stack, gather these bits and store them in a string that I could stick in my exception message. I really don't are how long such a method would take to execute as performance is no longer a concern when I hit one of these scenarios. If it's possible, I'm sure someone has done it. If that's the case, I'm having a hard time finding it. I think any search containing "exception" brings back too many resutls. Anyway, can this be done? If so, some examples or links would be great. Thanks in advance for your time, Robert

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  • Why does the BigFraction class in the Apache-Commons-Math library return incorrect division results?

    - by Timothy Lee Russell
    In the spirit of using existing, tested and stable libraries of code, I started using the Apache-Commons-Math library and its BigFraction class to perform some rational calculations for an Android app I'm writing called RationalCalc. It works great for every task that I have thrown at it, except for one nagging problem. When dividing certain BigFraction values, I am getting incorrect results. If I create a BigFraction with the inverse of the divisor and multiply instead, I get the same incorrect answer but perhaps that is what the library is doing internally anyway. Does anyone know what I am doing wrong? The division works correctly with a BigFraction of 2.5 but not 2.51, 2.49, etc... // *** incorrect! *** BigFraction one = new BigFraction(1.524); //one: 1715871458028159 / 1125899906842624 BigFraction two = new BigFraction(2.51); //two: 1413004383087493 / 562949953421312 BigFraction three = one.divide(two); //three: 0 Log.i("solve", three.toString()); //should be 0.607171315 ?? //returns 0 // *** correct! **** BigFraction four = new BigFraction(1.524); //four: 1715871458028159 / 1125899906842624 BigFraction five = new BigFraction(2.5); //five: 5 / 2 BigFraction six = four.divide(five); //six: 1715871458028159 / 2814749767106560 Log.i("solve", six.toString()); //should be 0.6096 ?? //returns 0.6096

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  • Why StrinUtils Apache class is not recognized in android?

    - by Maxood
    Why import org.apache.commons.lang.StringUtils cannot be imported in android by default. Do i have to include an external library? Then where can i find that library on the web? package com.myapps.urlencoding; import android.app.Activity; import org.apache.commons.lang.StringUtils; public class EncodeIdUtil extends Activity { /** Called when the activity is first created. */ private static Long multiplier=Long.parseLong("1zzzz",36); /** * Encodes the id. * @param id the id to encode * @return encoded string */ public static String encode(Long id) { return StringUtils.reverse(Long.toString((id*multiplier), 35)); } /** * Decodes the encoded id. * @param encodedId the encodedId to decode * @return the Id * @throws IllegalArgumentException if encodedId is not a validly encoded id. */ public static Long decode(String encodedId) throws IllegalArgumentException { long product; try { product = Long.parseLong(StringUtils.reverse(encodedId), 35); } catch (Exception e) { throw new IllegalArgumentException(); } if ( 0 != product % multiplier || product < 0) { throw new IllegalArgumentException(); } return product/multiplier; } }

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  • accessing a method from a button within a class?

    - by flo
    #import "GameObject.h" #import "Definitions.h" @implementation GameObject @synthesize owner; @synthesize state; @synthesize mirrored; @synthesize button; @synthesize switcher; - (id) init { if ( self = [super init] ) { [self setOwner: EmptyField]; button = [UIButton buttonWithType:UIButtonTypeCustom]; [self setSwitcher: FALSE]; } return self; } - (UIButton*) display{ button.frame = CGRectMake(0, 0, GO_Width, GO_Height); [button setBackgroundImage:[UIImage imageNamed:BlueStone] forState:UIControlStateNormal]; [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside]; return button; } -(void)buttonPressed:(id) sender { //... } } - (void) dealloc { [super dealloc]; } @end Hi! i would like to know if the above is possible somehow within a class (in my case it is called GameObject) or if i HAVE to have the button call a methode in the viewcontroller... the above results with the app crashing. i would call display within a loop on the viewcontroller and id like to change some of the GameObjects instance variables within buttonPressed. Also id like to change some other stuff by calling some other methods from within buttonPressed but i think that will be the lesser of my problems ;) also id like to know how i can pass some variables to the buttonPressed method... cant find it anywhere :( help on this one would be much appreciated ;) thanks flo

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  • Iphone SDK quesiton: How to make a Drawing method in a View class work using CGContextRef?

    - by SimpleCode
    I have these 2 methods in the View class. the drawRect method always gets called when the view is initalized. But i can't get the drawLine method to work. It doesn't do anything when it gets called. Am i supposed to deal with cgimagecontext or something like that? please help!! (void)drawRect:(CGRect)rect { // Drawing code // Drawing code CGContextRef contextRef = UIGraphicsGetCurrentContext(); //CGContextSetRGBFillColor(contextRef, 0, 0, 255, 1); CGContextSetRGBStrokeColor(contextRef, 0, 0, 0, 1); CGContextSetLineWidth(contextRef, 5.0); CGContextBeginPath(contextRef); CGContextMoveToPoint(contextRef, 0, 0); CGContextAddLineToPoint(contextRef, 320, 480); CGContextStrokePath(contextRef); } -(void)drawLine:(CGPoint)from to:(CGPoint) to { // Drawing code CGContextRef contextRef = UIGraphicsGetCurrentContext(); //CGContextSetRGBFillColor(contextRef, 0, 0, 255, 1); CGContextSetRGBStrokeColor(contextRef, 0, 128, 0, 1); CGContextSetLineWidth(contextRef, 5.0); CGContextBeginPath(contextRef); CGContextMoveToPoint(contextRef, 0, 0); CGContextAddLineToPoint(contextRef, 320, 50); CGContextStrokePath(contextRef); }

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  • Utility of List<T>.Sort() versus List<T>.OrderBy() for a member of a custom container class

    - by ccomet
    I've found myself running back through some old 3.5 framework legacy code, and found some points where there are a whole bunch of lists and dictionaries that must be updated in a synchronized fashion. I've determined that I can make this process infinitely easier to both utilize and understand by converging these into custom container classes of new custom classes. There are some points, however, where I came to concerns with organizing the contents of these new container classes by a specific inner property. For example, sorting by the ID number property of one class. As the container classes are primarily based around a generic List object, my first instinct was to write the inner classes with IComparable, and write the CompareTo method that compares the properties. This way, I can just call items.Sort() when I want to invoke the sorting. However, I've been thinking instead about using items = items.OrderBy(Func) instead. This way it is more flexible if I need to sort by any other property. Readability is better as well, since the property used for sorting will be listed in-line with the sort call rather than having to look up the IComparable code. The overall implementation feels cleaner as a result. I don't care for premature or micro optimization, but I like consistency. I find it best to stick with one kind of implementation for as many cases as it is appropriate, and use different implementations where it is necessary. Is it worth it to convert my code to use the LINQ OrderBy instead of using List.Sort? Is it a better practice to stick with the IComparable implementation for these custom containers? Are there any significant mechanical advantages offered by either path that I should be weighing the decision on? Or is their end-functionality equivalent to the point that it just becomes coder's preference?

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  • iPhone Apps, Objective C, a Graph, and Functions vs. Objects (or something like that)

    - by BillEccles
    Gentleones, I've got a UIImageView that I have in a UIView. This particular UIImageView displays a PNG of a graph. It's important for this particular view controller and another view controller to know what the graph "looks like," i.e., the function described by the PNG graph. These other view controllers need to be able to call a "function" of some sort with the X value returning the Y value. Please ignore the fact (from an outsider's perspective) that I could probably generate the graph programmatically. So my questions are: 1 - Where should I put this function? Should it go in one view controller or the other, or should it go in its own class or main or...? 2 - Should it be an object in some way? Or should it be a straight function? (In either case, where's it belong?) Pardon the apparent n00b-iness of the question. It's 'cause I'm honestly a n00b! This OOP stuff is giving my head a spin having been a procedural programmer for 30 years. (And I choose to learn it by jumping into an iPhone app. Talk about baptism by fire!) Thanks in advance,Bill

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  • Can someone tell me what this Java class does? I/O related

    - by anon
    I am relatively new to Java and trying to learn the I/O syntax. Could someone give me a general overview of what this code does? Thanks!! import java.io.*; public class FileReader { private String openFile=""; private String saveFile=""; FileReader(openFile, saveFile) { this.openFile=openFile; this.saveFile=saveFile; } public String process(){ System.out.println(this.openFile); System.out.println(this.saveFile); BufferedReader open=null; FileReader openFR=null; FileWriter save=null; int counter=0; String output=""; if(openFile.equals("")){ return "No open file specifified\n"; } if(this.saveFile.equals("")){ return "No save file specified\n"; } try { openFR = new FileReader(this.openFile); open = new BufferedReader(openFR); } catch (FileNotFoundException e) { return ("Open file no longer exists\n"); } try { save = new FileWriter(saveFile); } catch (IOException e){ return ("Error saving the file\n"); } try{ String temp = open.readLine(); while(temp != null){ temp = open.readLine(); counter++; save.write(output + "\n"); } } catch (IOException e){ e.getStackTrace(); return ("Error reading open file"); } try { save.flush(); } catch (IOException e) { e.printStackTrace(); return ("Error writing save file"); } return "Operation completed successfully"; } }

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  • How to change the css class="current" when using page jumping (single page website)?

    - by Bryan
    Morning, I must be asking google all the wrong questions, because I can't find anything similar. I have a standard navigation list, but I'm using page jumping because I wanted a single web page. <ul> <li><a href="#livestream">Livestream</a></li> <li><a href="#media">Media</a></li> <li><a href="#crew">Crew</a></li> <li><a href="#services">Services</a></li> <li><a href="#contact">Contact</a></li> </ul> But I can't for the life of me figure out how to make the class="current" when using page jumping. I've tried this bit of jquery because it appears to be what I'm looking for, but it did nothing. I don't think it'll work for #links. Any ideas?

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  • What's a reasonable way to mutate a primitive variable from an anonymous Java class?

    - by Steve
    I would like to write the following code: boolean found = false; search(new SearchCallback() { @Override void onFound(Object o) { found = true; } }); Obviously this is not allowed, since found needs to be final. I can't make found a member field for thread-safety reasons. What is the best alternative? One workaround is to define final class MutableReference<T> { private T value; MutableReference(T value) { this.value = value; } T get() { return value; } void set(T value) { this.value = value; } } but this ends up taking a lot of space when formatted properly, and I'd rather not reinvent the wheel if at all possible. I could use a List<Boolean> with a single element (either mutating that element, or else emptying the list) or even a Boolean[1]. But everything seems to smell funny, since none of the options are being used as they were intended. What is a reasonable way to do this?

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  • inheritance confusion. Adding a special class for making errors obvious on form validation

    - by aslum
    So I've got a form... The relevant CSS is (I think): .libform input { background-color:transparent; color:#000; border-left:0; border-right:0; border-top:0; border-bottom: 1px solid #555; margin: 0 5px 1px 5px; display:inline-block; } .libform input:focus { border:0; border-bottom: 1px dotted #000; color:#939; background-color:#fed; } .error { border-bottom: 1px solid red; } Form field: <? if ($name=="") {$nameerror="error";}?> <input name="name" type="text" class="<?php echo $nameerror;?>" value="<?echo $name;?>" id="name"> I'd like for when they've left the field blank the input button's underline to change from black to red. But it doesn't seem to inherit right. What am I doing wrong?

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  • How can I change the tags/css class of some dynamic text based on output from a helper?

    - by Angela
    I have a repeated line which outputs something like: Call John Jones in -3 days (status) I have a helper called show_status(contact,email) which will output whether that particular email had been sent to that particular contact. If it is "sent," then that entire line should show up as "strike out." Similarly, if the number of days is -3 (<0), the line should be formatted in red. Here's my hack, but there must be a cleaner way to put the logic into the controller? I hard-code a value that wraps around the lines I want formatted, and assign the value based on a separate call to the same helper: <% for call in @campaign.calls %> <% if !show_call_status(@contact,call).blank? %> <%= strike_start = '<s>'%> <%= strike_end = '</s>' %> <% end %> <p> <%= strike_start %> <%= link_to call.title, call_path(call) %> on <%= (@contact.date_entered + call.days).to_s(:long) %> in <%= interval_email(@contact,call) %> days <%= make_call(@contact,call) %> <span class='status'><%= show_call_status(@contact,call) %></span> <%= strike_end %> </p> <% end %> I guess what I'd like to do is not have the if statement in the View. Not sure how to do this.

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  • Catchable fatal error: Object of class view_user could not be converted to string in C:\xampp\xampp\htdocs\textile\admin\view_class.php on line 9 [closed]

    - by user1282142
    <?php include('config.inc'); class view_user { function view($user) { $temp = mysql_query("SELECT * from register_user where user_name = '$user'"); $value = mysql_fetch_array($temp); $query = mysql_query("SELECT order_user.design_name, order_user.reaad, order_user.pick, order_user.yarn_detail FROM register_user INNER JOIN order_user ON register_user.register_id = '$value[register_id]' and order_user.register_id = $value[register_id]"); if($query) { echo "<center><table border = 1> <tr> <th>Design Name</th> <th>Read</th> <th>Pick</th> <th>Design Detail</th> </tr>"; while($row = mysql_fetch_array($query)) { echo "<tr>"; echo "<td>$row[design_name]</td>"; echo "<td>$row[reaad]</td>"; echo "<td>$row[pick]</td>"; echo "<td>$row[yarn_detail]</td>"; echo"</tr></center>"; } } else { echo"User doesn't Exist"; include('footer1.php'); } } } ?>

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  • How to display panel which is of Singleton class in two different frames at a time?

    - by Sriku
    I am trying to display a singleton obj on two different Jframe, but it is displayed only in the Jframe in which the object is added at last ( in example Frame2). Other Jframe is empty. This Singleton class is inherited from Panel and contains a label in it. Can anybody please tell me how can i display this singleton object in two different frame ? public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { public void run() { NewJFrame inst = new NewJFrame(); inst.setTitle("Frame1"); inst.setSize(300, 300); inst.setLocationRelativeTo(null); inst.setVisible(true); singltonpanel _sin = singltonpanel.instance(); inst.add(_sin); inst.repaint(); JFrame frame = new JFrame("Frame2"); frame.setSize(300, 300); frame.setVisible(true); singltonpanel _sin1 = singltonpanel.instance(); frame.add(_sin1); frame.repaint(); } });

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  • Entity Framework LINQ Query using Custom C# Class Method - Once yes, once no - because executing on the client or in SQL?

    - by BrooklynDev
    I have two Entity Framework 4 Linq queries I wrote that make use of a custom class method, one works and one does not: The custom method is: public static DateTime GetLastReadToDate(string fbaUsername, Discussion discussion) { return (discussion.DiscussionUserReads.Where(dur => dur.User.aspnet_User.UserName == fbaUsername).FirstOrDefault() ?? new DiscussionUserRead { ReadToDate = DateTime.Now.AddYears(-99) }).ReadToDate; } The linq query that works calls a from after a from, the equivalent of SelectMany(): from g in oc.Users.Where(u => u.aspnet_User.UserName == fbaUsername).First().Groups from d in g.Discussions select new { UnReadPostCount = d.Posts.Where(p => p.CreatedDate > DiscussionRepository.GetLastReadToDate(fbaUsername, p.Discussion)).Count() }; The query that does not work is more like a regular select: from d in oc.Discussions where d.Group.Name == "Student" select new { UnReadPostCount = d.Posts.Where(p => p.CreatedDate > DiscussionRepository.GetLastReadToDate(fbaUsername, p.Discussion)).Count(), }; The error I get is: LINQ to Entities does not recognize the method 'System.DateTime GetLastReadToDate(System.String, Discussion)' method, and this method cannot be translated into a store expression. My question is, why am I able to use my custom GetLastReadToDate() method in the first query and not the second? I suppose this has something to do with what gets executed on the db server and what gets executed on the client? These queries seem to use the GetLastReadToDate() method so similarly though, I'm wondering why would work for the first and not the second, and most importantly if there's a way to factor common query syntax like what's in the GetLastReadToDate() method into a separate location to be reused in several different places LINQ queries. Please note all these queries are sharing the same object context.

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  • Why doesn't my UIViewController class keep track of an NSArray instance variable.

    - by TaoStoner
    Hey, I am new to Objective-C 2.0 and Xcode, so forgive me if I am missing something elementary here. Anyways, I am trying to make my own UIViewController class called GameView to display a new view. To work the game I need to keep track of an NSArray that I want to load from a plist file. I have made a method 'loadGame' which I want to load the correct NSArray into an instance variable. However it appears that after the method executes the instance variable loses track of the array. Its easier if I just show you the code.... @interface GameView : UIViewController { IBOutlet UIView *view IBOutlet UILabel *label; NSArray *currentGame; } -(IBOutlet)next; -(void)loadDefault; ... @implementation GameView - (IBOutlet)next{ int numElements = [currentGame count]; int r = rand() % numElements; NSString *myString = [currentGame objectAtIndex:(NSUInteger)r]; [label setText: myString]; } - (void)loadDefault { NSDictionary *games; NSString *path = [[NSBundle mainBundle] bundlePath]; NSString *finalPath = [path stringByAppendingPathComponent:@"Games.plist"]; games = [NSDictionary dictionaryWithContentsOfFile:finalPath]; currentGame = [games objectForKey:@"Default"]; } when loadDefault gets called, everything runs perfectly, but when I try to use the currentGame NSArray later in the method call to next, currentGame appears to be nil. I am also aware of the memory management issues with this code. Any help would be appreciated with this problem.

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  • Should I delete the string members of a C++ class?

    - by Bobby
    If I have the following declaration: #include <iostream> #include <string> class DEMData { private: int bitFldPos; int bytFldPos; std::string byteOrder; std::string desS; std::string engUnit; std::string oTag; std::string valType; int idx; public: DEMData(); DEMData(const DEMData &d); void SetIndex(int idx); int GetIndex() const; void SetValType(const char* valType); const char* GetValType() const; void SetOTag(const char* oTag); const char* GetOTag() const; void SetEngUnit(const char* engUnit); const char* GetEngUnit() const; void SetDesS(const char* desS); const char* GetDesS() const; void SetByteOrder(const char* byteOrder); const char* GetByteOrder() const; void SetBytFldPos(int bytFldPos); int GetBytFldPos() const; void SetBitFldPos(int bitFldPos); int GetBitFldPos() const; friend std::ostream &operator<<(std::ostream &stream, DEMData d); bool operator==(const DEMData &d) const; ~DEMData(); }; what code should be in the destructor? Should I "delete" the std::string fields?

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  • Computation overhead in C# - Using getters/setters vs. modifying arrays directly and casting speeds

    - by Jeffrey Kern
    I was going to write a long-winded post, but I'll boil it down here: I'm trying to emulate the graphical old-school style of the NES via XNA. However, my FPS is SLOW, trying to modify 65K pixels per frame. If I just loop through all 65K pixels and set them to some arbitrary color, I get 64FPS. The code I made to look-up what colors should be placed where, I get 1FPS. I think it is because of my object-orented code. Right now, I have things divided into about six classes, with getters/setters. I'm guessing that I'm at least calling 360K getters per frame, which I think is a lot of overhead. Each class contains either/and-or 1D or 2D arrays containing custom enumerations, int, Color, or Vector2D, bytes. What if I combined all of the classes into just one, and accessed the contents of each array directly? The code would look a mess, and ditch the concepts of object-oriented coding, but the speed might be much faster. I'm also not concerned about access violations, as any attempts to get/set the data in the arrays will done in blocks. E.g., all writing to arrays will take place before any data is accessed from them. As for casting, I stated that I'm using custom enumerations, int, Color, and Vector2D, bytes. Which data types are fastest to use and access in the .net Framework, XNA, XBox, C#? I think that constant casting might be a cause of slowdown here. Also, instead of using math to figure out which indexes data should be placed in, I've used precomputed lookup tables so I don't have to use constant multiplication, addition, subtraction, division per frame. :)

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  • jquery ui dialog open multiple dialog boxes using the same class on the button and the content div

    - by MichaelAntoni
    Hello there, i want to open multiple dialog boxes by using the same class on both the button and the content div. The below works but only for the first time. jQuery('.helpDialog').hide(); jQuery('.helpButton').click(function() { jQuery(this).next('.helpDialog').dialog({ autoOpen: true, title: 'Help', width: 500, height: 300, position: [180,10], draggable: true, resizable: false, modal: false }); return false; }); we know the reason for this http://blog.nemikor.com/2009/04/08/basic-usage-of-the-jquery-ui-dialog/ "the second call is ignored because the dialog has already been instantiated on that element." But when i fix that problem by trying the code below, the dialog box no longer opens. Can anyone help? Thanks in advance jQuery('.helpDialog').hide(); jQuery(function() { jQuery('.helpDialog').dialog({ autoOpen: false, modal: true, title: 'Info', width: 600, height: 400, position: [200,0], draggable: false }); }); jQuery('.helpButton').click(function() { jQuery(this).next('.helpDialog').dialog('open'); return false; });

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  • How can I store and access a filehandle in a Perl class?

    - by Haiyuan Zhang
    please look at the following code first. #! /usr/bin/perl package foo; sub new { my $pkg = shift; my $self = {}; my $self->{_fd} = undef; bless $self, $pkg; return $self; } sub Setfd { my $self = shift; my $fd = shift; $self_->{_fd} = $fd; } sub write { my $self = shift; print $self->{_fd} "hello word"; } my $foo = new foo; My intention is to store a file handle within a class using hash. the file handle is undefined at first, but can be initilized afterwards by calling Setfd function. then write can be called to actually write string "hello word" to a file indicated by the file handle, supposed that the file handle is the result of a success "write" open. but, perl compiler just complains that there are syntax error in the "print" line. can anyone of you tells me what's wrong here? thanks in advance.

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