Search Results

Search found 8692 results on 348 pages for 'patterns practices'.

Page 178/348 | < Previous Page | 174 175 176 177 178 179 180 181 182 183 184 185  | Next Page >

  • Concatenating Strings in Obj C

    - by eco_bach
    Hi It seems that Objective C jumps thru hoops to make seemingly simple tasks extremely difficult. I simply need to create a sequence of strings, image1.jpg, image2.jpg, etc etc ie in a loop var imgString:String='image'+i+'.jpg; I assume a best practice is to use a NSMutableString with appendString method? What am I doing wrong?? NSMutableString *imgString; for(int i=1;i<=NUMIMAGES;i++){ imgString.appendString(@"image"+i+@".jpg"); } I get the following error error: request for member 'appendString' in something not a structure or union

    Read the article

  • Writing my own implementation of stl-like Iterator in C++.

    - by Negai
    Good evening everybody, I'm currently trying to understand the intrinsics of iterators in various languages i.e. the way they are implemented. For example, there is the following class exposing the list interface. template<class T> class List { public: virtual void Insert( int beforeIndex, const T item ) throw( ListException ) =0 ; virtual void Append( const T item ) =0; virtual T Get( int position ) const throw( ListException ) =0; virtual int GetLength() const =0; virtual void Remove( int position ) throw( ListException ) =0; virtual ~List() =0 {}; }; According to GoF, the best way to implement an iterator that can support different kinds of traversal is to create the base Iterator class (friend of List) with protected methods that can access List's members. The concrete implementations of Iterator will handle the job in different ways and access List's private and protected data through the base interface. From here forth things are getting confusing. Say, I have class LinkedList and ArrayList, both derived from List, and there are also corresponding iterators, each of the classes returns. How can I implement LinkedListIterator? I'm absolutely out of ideas. And what kind of data can the base iterator class retrieve from the List (which is a mere interface, while the implementations of all the derived classes differ significantly) ? Sorry for so much clutter. Thanks.

    Read the article

  • How do I get mercurial to show the diff during `hg com`?

    - by Kev
    Is there a way to configure hg com so that in the commit message file that pops up in the external editor, instead of just showing which files were changed (in the HG: lines) it actually shows the full diff? I'd rather view the output and compose my commit message simultaneously from the comfort of my text editor as opposed to doing hg diff on the command line separately beforehand.

    Read the article

  • Do I need to perform a commit after a rebase?

    - by Benjol
    I've just rebased a feature branch onto another feature branch (in preparation for rebasing everything to the head of my master), and it involved quite a few tricky merge resolutions. Is the rebase automatically saved as a commit somewhere? Just where do those modifications live? I can't see anything in gitk, or git log --oneline. (Same question for when I merge back my branch after rebasing.)

    Read the article

  • Formating a date field in the Model (Codeigniter)

    - by Landitus
    Hi, I', trying to re-format a date from a table in Codeigniter. The Controller is for a blog. I was succesfull when the date conversion happens in the View. I was hoping to convert the date in the Model to have things in order. This is the Model: class Novedades_model extends Model { function getAll() { $this->db->order_by('date','desc'); $query = $this->db->get('novedades'); if($query->num_rows() > 0) { foreach ($query->result() as $row) { $data[] = $row; } } return $data; } } This is part of the controller $this->load->model('novedades_model'); $data['records'] = $this->novedades_model->getAll(); Here's the date conversion as it happens in the View. This is inside the posts loop: <?php foreach($records as $row) : ?> <?php $fdate = "%d <abbr>%M</abbr> %Y"; $dateConv = mdate($fdate, mysql_to_unix($row->date)); ?> <div class="article section"> <span class="date"><?php echo $dateConv ;?></span> ... Keeps going ... How can I convert the date in the Model? Can I access the date key and refactor it?

    Read the article

  • Sequencing ajax requests

    - by Scott Evernden
    I find I sometimes need to iterate some collection and make an ajax call for each element. I want each call to return before moving to the next element so that I don't blast the server with requests - which often leads to other issues. And I don't want to set async to false and freeze the browser. Usually this involves setting up some kind of iterator context that i step thru upon each success callback. I think there must be a cleaner simpler way? Does anyone have a clever design pattern for how to neatly work thru a collection making ajax calls for each item?

    Read the article

  • int i vs int index etc. Which one is better?

    - by Earlz
    Coming from a C background I've always used int i for generic loop variables. Of course in big nested loops or other complex things I may use a descriptive name but which one had you rather see? int i; for(i=0;i<Controls.Count;i++){ DoStuff(Controls[i]); } or int index; for(index=0;index<Controls.Count;index++){ DoStuff(Controls[index]); } In the current project I am working on there are both of these styles and index being replaced by ndx. Which one is better? Is the i variable too generic? Also what about the other C style names? i, j, k Should all of these be replaced by actual descriptive variables?

    Read the article

  • User submitted content filtering

    - by Jim
    Hey all, Does anyone have any ideas on what could be used as a way to filter untrustworthy user submitted content? Take Yelp for instance, they would need to prevent competitors writing business reviews on their competitors. They would need to prevent business owners favourably reviewing their own business, or forcing friends/family to do so. They would need to prevent poor quality reviews from affecting a businesses rating and so on. I can't think what they might use to do this: Prevent multiple users from the same IP reviewing certain things Prevent business owners reviewing their own business (maybe even other businesses in the same categories as their own?) Somehow determine what a review is about and what the actual intentions behind it are Other than the first and second points, I can't think of any clever/easy way to filter potentially harmful reviews from being made available, other than a human doing it. Obviously for a site the size of Yelp this wouldn't be feasible, so what parameters could they take into consideration? Even with human intervention, how would anyone know it was the owners best buddy writing a fake review without knowing the people? I'm using this as an example in a larger study on the subject of filtering user content automatically. Does anyone have any ideas how these systems may work and what they take into consideration? Thanks!

    Read the article

  • Exception handling pattern

    - by treefrog
    It is a common pattern I see where the error codes associated with an exception are stored as Static final ints. when the exception is created to be thrown, it is constructed with one of these codes along with an error message. This results in the method that is going to catch it having to look at the code and then decide on a course of action. The alternative seems to be- declare a class for EVERY exception error case Is there a middle ground ? what is the recommended method ?

    Read the article

  • benefit os having a factory for object creation?

    - by ajsie
    im trying to understand the factory design pattern. i dont understand why it's good to have a middleman between the client and the product (object that the client wants). example with no factory: $mac = new Mac(); example with a factory: $appleStore = new AppleStore(); $mac = $appleStore->getProduct('mac'); how does the factory pattern decouple the client from the product? could someone give an example of a future code change that will impact on example 1 negative, but positive in example 2 so i understand the importance of decoupling? thanks

    Read the article

  • require_once at the beginning or when really needed?

    - by takeshin
    Where should I put require_once statements, and why? Always on the beginning of a file, before the class, In the actual method when the file is really needed It depends ? Most frameworks put includes at the beginning and do not care if the file is really needed. Using autoloader is the other case here.

    Read the article

  • Mandatory method documentation

    - by Sjoerd
    On my previous job, providing all methods with javadoc was mandatory, which resulted in things like this: /** * Sets the Frobber. * * @param frobber The frobber */ public setFrobber(Frobber frobber) { ... } As you can see, the documentation adds little to the code, but takes up space and work. Should documenting all methods be mandatory or optional? Is there a rule for which methods to document? What are pros and cons of requiring every method to be documented?

    Read the article

  • When to use basic types (Integer, String), and when to write a new class?

    - by belgarat
    Stackoverflow users: A lot of things can be represented in programs by using the basic types, or we can create a new class for it. Example: A social security number can be a number, string or its own object. (Other common examples: Phone numbers, names, zip codes, user id, order id and other id's.) My question is: When should the basic types be used, and when should we write ourselves a new class? I see that when you need to add behavior, you'll want to create a class (example, social security number parsing, validation, formatting, etc). But is this the only criteria? I have come across cases where many of these things are represented as java Integers and/or Strings. We loose the benefit of type-checking, and I have often seen bugs caused by parameters being mixed in calls to function(Intever, Integer, Integer, Integer). On the other hand, some programmers are opposed to over-designing by creating classes for "eveything". Obviously, the answer is "it depends". But, what do you think, and what do you normally do?

    Read the article

  • What is the best way to restore(rollback) data in an application to a specified state(date) ?

    - by panzerschreck
    Hello, An example would set the context right, the example below captures the various states of the entity, which needs to be reverted(rolled back) . State 1 - Recorded on 01-Mar-2010 Column1 Column2 Data1 0.56 State 2 - Recorded on 02-Mar-2010 Column1 Column2 Data1 0.57 State 3 - Recorded on 03-Mar-2010 Column1 Column2 Data1 0.58 User notices that state3 is not what he intended to be in, decides to revert back to state2. One approach that I can think of, without modifying the entity is via "auditing" all the inserts/updates, as below, the rollback information captures the data just before the updates/modifications on the entity, so that it can be applied in an order when you need to revert.Please note that changing the entity's schema, is not an option. Rollback - R1 recorded on 01-Mar-2010 Column1 Column2 Data1 0.56 Rollback - R2 Recorded on 02-Mar-2010 Column1 Column2 Data1 0.56 Rollback - R3 Recorded on 03-Mar-2010 Column1 Column2 Data1 0.57 So, to get to state2 , we would start with rollback information R1,apply R2 onto it. Is there a better approach to achieve this ? Thanks for your time.

    Read the article

  • Structuring iPhone/iPad application views

    - by Mark
    I have an idea about an application that I want to build and Im new to iPhone/iPad development (but not new to development in other languages/frameworks such as .NET and Java). I want to layout some views on the screen so that they animate (slide in) from different directions into their places. The question is about the strucuture of the application, if I have say 4 rectanglular areas on the screen that contain business data, such as contacts (name, photo, etc...) and they all take up different widths of the screen (say the first contact takes up one row of the screen, but the next 2 take up half the width of the next row each, and so on). Should I create a custom view for the different sized contact views, (i.e. LargeCustomView and SmallCustomView, and any other special type that I make) or should it all be one type, say, CustomerDetailsView which could be stretched to fit at design time? Also, if there were, say, 3 different instances of the same custom view on the one screen, are there 3 instances of the view controller also? Im a little confused about powering the data behind a view, can someone shed some light on this for me? Do I just set the properties (say an instance variable ContactForView) on the view controller for each instance? Thanks for any help you can give Cheers, Mark

    Read the article

  • slowing down a loop in a recursive function

    - by eco_bach
    I have a difficult problem with a recursive function. Essentially I need to 'slow down' a for loop within a function that repeatedly calls itself(the function); Is this possible, or do I need to somehow extract the recursive nature of the function? function callRecursiveFuncAgain(ob:Object):void{ //do recursive stuff; for (var i:int = 0; i < 4; i++) { _nextObj=foo callRecursiveFuncAgain(_nextObj); } }

    Read the article

  • Where does the query language sit within the MVC pattern?

    - by weesilmania
    I'd assume that since the query language sits within the controller (typically) that it belongs to that component, but if I play devil's advocate I'd argue that the query language is execute within the domain of the model, and is tightly coupled to that component so it might also be a part of it. Anyone know the answer? Is there a straight answer or is it technology specific?

    Read the article

  • how to organize classes in ruby if they are literal subclasses

    - by RetroNoodle
    I know that title didn't make sense, Im sorry! Its hard to word what I am trying to ask. I had trouble googling it for the same reason. So this isn't even Ruby specific, but I am working in ruby and I am new to it, so bear with me. So you have a class that is a document. Inside each document, you have sentences, and each sentence has words. Words will have properties, like "noun" or a count of how many times they are used in the document, etc. I would like each of the elements, document, sentence, word be an object. Now, if you think literally - sentences are in documents, and words are in sentences. Should this be organized literally like this as well? Like inside the document class you will define and instantiate the sentence objects, and inside the sentence class you will define and instantiate the words? Or, should everything be separate and reference each other? Like the word class would sit outside the sentence class but the sentence class would be able to instantiate and work with words? This is a basic OOP question I guess, and I suppose you could argue to do it either way. What do you guys think? Each sentence in the document could be stored in a hash of sentence objects inside the document object, and each word in the sentence could be stored in a hash of word objects inside the sentence. I dont want to code myself into a corner here, thats why I am asking, plus I have wondered this before in other situations. Thank you!

    Read the article

  • Factory Method Using Is/As Operator

    - by Swim
    I have factory that looks something like the following snippet. Foo is a wrapper class for Bar and in most cases (but not all), there is a 1:1 mapping. As a rule, Bar cannot know anything about Foo, yet Foo takes an instance of Bar. Is there a better/cleaner approach to doing this? public Foo Make( Bar obj ) { if( obj is Bar1 ) return new Foo1( obj as Bar1 ); if( obj is Bar2 ) return new Foo2( obj as Bar2 ); if( obj is Bar3 ) return new Foo3( obj as Bar3 ); if( obj is Bar4 ) return new Foo3( obj as Bar4 ); // same wrapper as Bar3 throw new ArgumentException(); } At first glance, this question might look like a duplicate (maybe it is), but I haven't seen one exactly like it. Here is one that is close, but not quite: http://stackoverflow.com/questions/242097/factory-based-on-typeof-or-is-a

    Read the article

< Previous Page | 174 175 176 177 178 179 180 181 182 183 184 185  | Next Page >