Search Results

Search found 5915 results on 237 pages for 'practices'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 85/237 | < Previous Page | 81 82 83 84 85 86 87 88 89 90 91 92  | Next Page >

  • Best strategy for synching data in iPhone app

    - by iamj4de
    I am working on a regular iPhone app which pulls data from a server (XML, JSON, etc...), and I'm wondering what is the best way to implement synching data. Criteria are speed (less network data exchange), robustness (data recovery in case update fails), offline access and flexibility (adaptable when the structure of the database changes slightly, like a new column). I know it varies from app to app, but can you guys share some of your strategy/experience? For me, I'm thinking of something like this: 1) Store Last Modified Date in iPhone 2) Upon launching, send a message like getNewData.php?lastModifiedDate=... 3) Server will process and send back only modified data from last time. 4) This data is formatted as so: <+><data id="..."></data></+> // add this to SQLite/CoreData <-><data id="..."></data></-> // remove this <%><data id="..."><attribute>newValue</attribute></data></%> // new modified value I don't want to make <+, <-, <%... for each attribute as well, because it would be too complicated, so probably when receive a <% field, I would just remove the data with the specified id and then add it again (assuming id here is not some automatically auto-incremented field). 5) Once everything is downloaded and updated, I will update the Last Modified Date field. The main problem with this strategy is: If the network goes down when I am updating something = the Last Modified Date is not yet updated = next time I relaunch the app, I will have to go through the same thing again. Not to mention potential inconsistent data. If I use a temporary table for update and make the whole thing atomic, it would work, but then again, if the update is too long (lots of data change), the user has to wait a long time until new data is available. Should I use Last-Modified-Date for each of the data field and update data gradually?

    Read the article

  • Is it better to use List or Collection?

    - by Vivin Paliath
    I have an object that stores some data in a list. The implementation could change later, and I don't want to expose the internal implementation to the end user. However, the user must have the ability to modify and access this collection of data. Currently I have something like this: public List<SomeDataType> getData() { return this.data; } public void setData(List<SomeDataType> data) { this.data = data; } Does this mean that I have allowed the internal implementation details to leak out? Should I be doing this instead? public Collection<SomeDataType> getData() { return this.data; } public void setData(Collection<SomeDataType> data) { this.data = new ArrayList<SomeDataType>(data); }

    Read the article

  • Should ActionResult perform other tasks too

    - by Ori
    In Asp.net MVC one is encouraged to derive custom ActionResults, however should these classes handle other tasks unrelated to views, perhaps a EmailActionResult would render a view then send an email. What is best practice for the class ActionResult, is it only view specific? I want to keep things DRY too. Should the sending of the email be factored into a service class? perhaps using a filter would work. what are your thoughts?

    Read the article

  • PHP Database connection practice

    - by Phill Pafford
    I have a script that connects to multiple databases (Oracle, MySQL and MSSQL), each database connection might not be used each time the script runs but all could be used in a single script execution. My question is, "Is it better to connect to all the databases once in the beginning of the script even though all the connections might not be used. Or is it better to connect to them as needed, the only catch is that I would need to have the connection call in a loop (so the database connection would be new for X amount of times in the loop). Yeah Example Code #1: // Connections at the beginning of the script $dbh_oracle = connect2db(); $dbh_mysql = connect2db(); $dbh_mssql = connect2db(); for ($i=1; $i<=5; $i++) { // NOTE: might not use all the connections $rs = queryDb($query,$dbh_*); // $dbh can be any of the 3 connections } Yeah Example Code #2: // Connections in the loop for ($i=1; $i<=5; $i++) { // NOTE: Would use all the connections but connecting multiple times $dbh_oracle = connect2db(); $dbh_mysql = connect2db(); $dbh_mssql = connect2db(); $rs_oracle = queryDb($query,$dbh_oracle); $rs_mysql = queryDb($query,$dbh_mysql); $rs_mssql = queryDb($query,$dbh_mssql); } now I know you could use a persistent connection but would that be one connection open for each database in the loop as well? Like mysql_pconnect(), mssql_pconnect() and adodb for Oracle persistent connection method. I know that persistent connection can also be resource hogs and as I'm looking for best performance/practice.

    Read the article

  • Using different numeric variable types

    - by DataPimp
    Im still pretty new so bear with me on this one, my question(s) are not meant to be argumentative or petty but during some reading something struck me as odd. Im under the assumption that when computers were slow and memory was expensive using the correct variable type was much more of a necessity than it is today. Now that memory is a bit easier to come by people seem to have relaxed a bit. For example, you see this sample code everywhere: for (int i = 0; i < length; i++) int? (-2,147,483,648 to 2,147,483,648) for length? Isnt byte (0-255) a better choice? So Im curious of your opinion and what you believe to be best practice, I hate to think this would be used only because the acronym "int" is more intuitive for a beginner...or has memory just become so cheap that we really dont need to concern ourselves with such petty things and therefore we should just use long so we can be sure any other numbers/types(within reason) used can be cast automagically? ...or am Im just being silly by concerning myself with such things?

    Read the article

  • What is the most elegant way to validate the presence of ONLY one out of two attributes using Rails?

    - by marcgg
    class Followup < ActiveRecord::Base belongs_to :post belongs_to :comment end This model needs to only have either a post or a comment, but only one of the two. Here's the rspec for what I'm trying to do: it "should be impossible to have both a comment and a post" do followup = Followup.make followup.comment = Comment.make followup.should be_valid followup.post = Post.make followup.should_not be_valid end I can see a bunch of ways of doing this, but what would be the most elegant way of doing this?

    Read the article

  • QT/PyQT best practice for using QT Designer

    - by pierocampanelli
    What is your development approach with QT/PYQT and QT Designer ? Are you doing this: Put all components on the panel (without any layout) and arrange them Put components in layout (Align Vertically/Horizontally/Form/Grid) Generate UI file and start coding how do you manage when you have custom widget ? For example when you have to fine tune behaviour of a QButton or QLineEdit ? Is it possible to add this custom widget to designer?

    Read the article

  • Practical rules for premature optimization

    - by DougW
    It seems that the phrase "Premature Optimization" is the buzz-word of the day. For some reason, iphone programmers in particular seem to think of avoiding premature optimization as a pro-active goal, rather than the natural result of simply avoiding distraction. The problem is, the term is beginning to be applied more and more to cases that are completely inappropriate. For example, I've seen a growing number of people say not to worry about the complexity of an algorithm, because that's premature optimization (eg http://stackoverflow.com/questions/2190275/help-sorting-an-nsarray-across-two-properties-with-nssortdescriptor/2191720#2191720). Frankly, I think this is just laziness, and appalling to disciplined computer science. But it has occurred to me that maybe considering the complexity and performance of algorithms is going the way of assembly loop unrolling, and other optimization techniques that are now considered unnecessary. What do you think? Are we at the point now where deciding between an O(n^n) and O(n!) complexity algorithm is irrelevant? What about O(n) vs O(n*n)? What do you consider "premature optimization"? What practical rules do you use to consciously or unconsciously avoid it? This is a bit vague, but I'm curious to hear other peoples' opinions on the topic.

    Read the article

  • Super user powers in development environment?

    - by red tiger
    Is it too much to ask for when I ask the IT department to give my development team an environment where we can use whatever software that we can download without having to have security check those tools? Of course, the software can be checked by security before deploying to Test, and the development environment can be on a VLAN that is not accessible from outside. This would greatly aid us by allowing us to use whatever open-source testing tools that we want. I'm asking because we have such tight restrictions on the software approval process, and I hear of other teams that have an environment where they can configure their local server however they want and they can use whatever tools they want. What's the norm out there? Thank you for any comments!

    Read the article

  • Is my method for avoiding dynamic_cast<> faster than dynamic_cast<> itself ?

    - by ereOn
    Hi, I was answering a question a few minutes ago and it raised to me another one: In one of my projects, I do some network message parsing. The messages are in the form of: [1 byte message type][2 bytes payload length][x bytes payload] The format and content of the payload are determined by the message type. I have a class hierarchy, based on a common class Message. To instanciate my messages, i have a static parsing method which gives back a Message* depending on the message type byte. Something like: Message* parse(const char* frame) { // This is sample code, in real life I obviously check that the buffer // is not NULL, and the size, and so on. switch(frame[0]) { case 0x01: return new FooMessage(); case 0x02: return new BarMessage(); } // Throw an exception here because the mesage type is unknown. } I sometimes need to access the methods of the subclasses. Since my network message handling must be fast, I decived to avoid dynamic_cast<> and I added a method to the base Message class that gives back the message type. Depending on this return value, I use a static_cast<> to the right child type instead. I did this mainly because I was told once that dynamic_cast<> was slow. However, I don't know exactly what it really does and how slow it is, thus, my method might be as just as slow (or slower) but far more complicated. What do you guys think of this design ? Is it common ? Is it really faster than using dynamic_cast<> ? Any detailed explanation of what happen under the hood when one use dynamic_cast<> is welcome !

    Read the article

  • Should a Unit-test replicate functionality or Test output?

    - by Daniel Beardsley
    I've run into this dilemma several times. Should my unit-tests duplicate the functionality of the method they are testing to verify it's integrity? OR Should unit tests strive to test the method with numerous manually created instances of inputs and expected outputs? I'm mainly asking the question for situations where the method you are testing is reasonably simple and it's proper operation can be verified by glancing at the code for a minute. Simplified example (in ruby): def concat_strings(str1, str2) return str1 + " AND " + str2 end Simplified functionality-replicating test for the above method: def test_concat_strings 10.times do str1 = random_string_generator str2 = random_string_generator assert_equal (str1 + " AND " + str2), concat_strings(str1, str2) end end I understand that most times the method you are testing won't be simple enough to justify doing it this way. But my question remains; is this a valid methodology in some circumstances (why or why not)?

    Read the article

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

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

    Read the article

  • Using table-of-contents in code?

    - by AareP
    Do you use table-of-contents for listing all the functions (and maybe variables) of a class in the beginning of big source code file? I know that alternative to that kind of listing would be to split up big files into smaller classes/files, so that their class declaration would be self-explanatory enough.. but some complex tasks require a lot of code. I'm not sure is it really worth it spending your time subdividing implementation into multiple of files? Or is it ok to create an index-listing additionally to the class/interface declaration?

    Read the article

  • What are the worst examples of moral failure in the history of software engineering?

    - by Amanda S
    Many computer science curricula include a class or at least a lecture on disasters caused by software bugs, such as the Therac-25 incidents or Ariane 5 Flight 501. Indeed, Wikipedia has a list of software bugs with serious consequences, and a question on StackOverflow addresses some of them too. We study the failures of the past so that we don't repeat them, and I believe that rather than ignoring them or excusing them, it's important to look at these failures squarely and remind ourselves exactly how the mistakes made by people in our profession cost real money and real lives. By studying failures caused by uncaught bugs and bad process, we learn certain lessons about rigorous testing and accountability, and we make sure that our innocent mistakes are caught before they cause major problems. There are kinds of less innocent failure in software engineering, however, and I think it's just as important to study the serious consequences caused by programmers motivated by malice, greed, or just plain amorality. Thus we can learn about the ethical questions that arise in our profession, and how to respond when we are faced with them ourselves. Unfortunately, it's much harder to find lists of these failures--the only one I can come up with is that apocryphal "DOS ain't done 'til Lotus won't run" story. What are the worst examples of moral failure in the history of software engineering?

    Read the article

  • How do you go from an abstract project description to actual code?

    - by Jason
    Maybe its because I've been coding around two semesters now, but the major stumbling block that I'm having at this point is converting the professor's project description and requirements to actual code. Since I'm currently in Algorithms 101, I basically do a bottom-up process, starting with a blank whiteboard and draw out the object and method interactions, then translate that into classes and code. But now the prof has tossed interfaces and abstract classes into the mix. Intellectually, I can recognize how they work, but am stubbing my toes figuring out how to use these new tools with the current project (simulating a web server). In my professors own words, mapping the abstract description to Java code is the real trick. So what steps are best used to go from English (or whatever your language is) to computer code? How do you decide where and when to create an interface, or use an abstract class?

    Read the article

  • Best practice for storage and retrieval of error messages.

    - by ferrari fan
    What is a best practice for storing user messages in a configuration file and then retrieving them for certain events throughout an application? I was thinking of having 1 single configuration file with entries such as REQUIRED_FIELD = {0} is a required field INVALID_FORMAT = The format for {0} is {1} etc. and then calling them from a class that would be something like this public class UIMessages { public static final String REQUIRED_FIELD = "REQUIRED_FIELD"; public static final String INVALID_FORMAT = "INVALID_FORMAT"; static { // load configuration file into a "Properties" object } public static String getMessage(String messageKey) { // return properties.getProperty(messageKey); } } Is this the right way to approach this problem or is there some de-facto standard already in place?

    Read the article

  • Design patterns to avoid

    - by Brian Rasmussen
    A lot of people seem to agree, that the Singleton pattern has a number of drawbacks and some even suggest to avoid the pattern all together. There's an excellent discussion here. Please direct any comments about the Singleton pattern to that question. Are there other design patterns, that should be avoided or used with great care?

    Read the article

  • Generic data input form in asp.net mvc application

    - by Diego
    Hello, I have an application that have EF 16 classes that share this information: They all are classes only with a key field and a description. I think it should be a waste if I make a controller with just 1 method just to present a form to fill these classes info, then I was thinking in to make a generic form(with key, description) and dynamically fill the right class through a sort of selection the selected info in any way, any good suggestion or pattern to do that? Where the generic methods should be located.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 81 82 83 84 85 86 87 88 89 90 91 92  | Next Page >