Search Results

Search found 6987 results on 280 pages for 'examples'.

Page 217/280 | < Previous Page | 213 214 215 216 217 218 219 220 221 222 223 224  | Next Page >

  • Adding figures using contextual menu - Eclipse GEF

    - by darkie15
    All, I am creating a palette less eclipse plugin where am adding figures to the custom editor through the contextual menu, but am not finding a way to do it. Can anyone please guide me as to how to go about adding figures to editor dynamically through context menu i.e. adding actions/commands. Since Eclipse GEF plugin development finds so less examples to look at, I am adding my solution so others find it useful. This code helps to render a node to the editor. Source code for Action class to render figures to the editor: public class AddNodeAction extends EditorPartAction { public static final String ADD_NODE = "ADDNODE"; public AddNodeAction(IEditorPart editor) { super(editor); setText("Add a Node"); setId(ADD_NODE); // Important to set ID } public void run() { <ParentModelClass> parent= (<ParentModelClass>)getEditorPart().getAdapter(<ParentModelClass>.class); if (parent== null) return; CommandStack command = (CommandStack)getEditorPart().getAdapter(CommandStack.class); if (command != null) { CompoundCommand totalCmd = new CompoundCommand(); <ChildModelToRenderFigureCommand>cmd = new <ChildModelToRenderFigureCommand>(parent); cmd.setParent(parent); <ChildModelClass> newNode = new <ChildModelClass>(); cmd.setNode(newNode); cmd.setLocation(getLocation()); // Any location you wish to set to totalCmd.add(cmd); command.execute(totalCmd); } } @Override protected boolean calculateEnabled() { return true; } }

    Read the article

  • Practical refactoring using unit tests

    - by awhite
    Having just read the first four chapters of Refactoring: Improving the Design of Existing Code, I embarked on my first refactoring and almost immediately came to a roadblock. It stems from the requirement that before you begin refactoring, you should put unit tests around the legacy code. That allows you to be sure your refactoring didn't change what the original code did (only how it did it). So my first question is this: how do I unit-test a method in legacy code? How can I put a unit test around a 500 line (if I'm lucky) method that doesn't do just one task? It seems to me that I would have to refactor my legacy code just to make it unit-testable. Does anyone have any experience refactoring using unit tests? And, if so, do you have any practical examples you can share with me? My second question is somewhat hard to explain. Here's an example: I want to refactor a legacy method that populates an object from a database record. Wouldn't I have to write a unit test that compares an object retrieved using the old method, with an object retrieved using my refactored method? Otherwise, how would I know that my refactored method produces the same results as the old method? If that is true, then how long do I leave the old deprecated method in the source code? Do I just whack it after I test a few different records? Or, do I need to keep it around for a while in case I encounter a bug in my refactored code? Lastly, since a couple people have asked...the legacy code was originally written in VB6 and then ported to VB.NET with minimal architecture changes.

    Read the article

  • Understanding Java Wait and Notify methods

    - by Maddy
    Hello all: I have a following program: import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; public class SimpleWaitNotify implements Runnable { final static Object obj = new Object(); static boolean value = true; public synchronized void flag() { System.out.println("Before Wait"); try { obj.wait(); } catch (InterruptedException e) { System.out.println("Thread interrupted"); } System.out.println("After Being Notified"); } public synchronized void unflag() { System.out.println("Before Notify All"); obj.notifyAll(); System.out.println("After Notify All Method Call"); } public void run() { if (value) { flag(); } else { unflag(); } } public static void main(String[] args) throws InterruptedException { ExecutorService pool = Executors.newFixedThreadPool(4); SimpleWaitNotify sWait = new SimpleWaitNotify(); pool.execute(sWait); SimpleWaitNotify.value = false; SimpleWaitNotify sNotify = new SimpleWaitNotify(); pool.execute(sNotify); pool.shutdown(); } } When I wait on obj, I get the following exception Exception in thread "pool-1-thread-1" java.lang.IllegalMonitorStateException: current thread not owner for each of the two threads. But if I use SimpleWaitNotify's monitor then the program execution is suspended. In other words, I think it suspends current execution thread and in turn the executor. Any help towards understanding what's going on would be duly appreciated. This is an area1 where the theory and javadoc seem straightforward, and since there aren't many examples, conceptually left a big gap in me.

    Read the article

  • Getting Depth Value on Kinect SDK 1.6

    - by AlexanderPD
    this is my first try on Kinect and Kinect SDK so I'm having a lot of "newbie issues" :) my goal is to point my mouse on the Kinect standard video output and get the depth value. I already have both normal video and depth video outputs by using the 2 "Color Basic-WPF" and "Depth Basic-WPF" samples, and handling mouse events or position is not a problem. In fact i already did all and i already got a depth value, but this value is always HIGHLY imprecise. It jumps from 500 to 4000 by just moving to the next pixel in a plane surface. So.. I'm pretty sure I'm reading the depth value in the wrong way. This is how i read it: short debugValue = depthPixels[x*y].Depth; debug.Text = "X = "+x+", Y = "+y+", value = "+debugValue.ToString(); i know it's pretty out of context, this little piece of code is inside the same SensorDepthFrameReady function in "Depth Basic-WPF"! "x" and "y" are the mouse coordinates and depthPixels is DepthImagePixel[] type, a temporary array filled with the "depthFrame.CopyDepthImagePixelDataTo(this.depthPixels);" instruction. Depth frame is filled here: DepthImageFrame depthFrame = e.OpenDepthImageFrame() the "e" comes from here: private void SensorDepthFrameReady(object sender, DepthImageFrameReadyEventArgs e) and this last one is called here: this.sensor.DepthFrameReady += this.SensorDepthFrameReady; how i must handle that depth value i get? I know the value must be between 800 and 4000 but i get values between about 500 and about 8000. i already google a lot (here on SO too) and i still can't understand if the depth value is 11 or 13 bit. The sdk examples uses shrink this value to 8 bit and this is making even more confusion in my head :(

    Read the article

  • Hibernate query for multiple items in a collection

    - by aarestad
    I have a data model that looks something like this: public class Item { private List<ItemAttribute> attributes; // other stuff } public class ItemAttribute { private String name; private String value; } (this obviously simplifies away a lot of the extraneous stuff) What I want to do is create a query to ask for all Items with one OR MORE particular attributes, ideally joined with arbitrary ANDs and ORs. Right now I'm keeping it simple and just trying to implement the AND case. In pseudo-SQL (or pseudo-HQL if you would), it would be something like: select all items where attributes contains(ItemAttribute(name="foo1", value="bar1")) AND attributes contains(ItemAttribute(name="foo2", value="bar2")) The examples in the Hibernate docs didn't seem to address this particular use case, but it seems like a fairly common one. The disjunction case would also be useful, especially so I could specify a list of possible values, i.e. where attributes contains(ItemAttribute(name="foo", value="bar1")) OR attributes contains(ItemAttribute(name="foo", value="bar2")) -- etc. Here's an example that works OK for a single attribute: return getSession().createCriteria(Item.class) .createAlias("itemAttributes", "ia") .add(Restrictions.conjunction() .add(Restrictions.eq("ia.name", "foo")) .add(Restrictions.eq("ia.attributeValue", "bar"))) .list(); Learning how to do this would go a long ways towards expanding my understanding of Hibernate's potential. :)

    Read the article

  • How should a programmer go about getting started with Flash/Flex/ActionScript?

    - by Graphics Noob
    What is the shortest path between zero (ie no flash related development software on my computer or information about where to obtain it or get started) to running a "hello world" ActionScript? I'm hoping for an answer that gives step by step instructions about exactly what software is needed to get started, an example of some "hello world" code, and instructions for compiling and running the code. I've spent more time than I think should be necessary researching this question and not found much information. Hopefully this question will be found by programmers like me who want to get started with Flash/Flex/ActionScript (After my morning of researching I still don't even know what terminology to use so I'll just throw it all out there). ActionScript tutorials I've found are focused on programming concepts, ie logic, branching, OOP, etc, and some even have code examples to download, but not a single one I've found explains how to compile and run the code. They all seem to assume you have an IDE standing by but no knowledge of programming, exactly the opposite of the position I'm in. Here are the most related SO questions I've found: http://stackoverflow.com/questions/59083/what-is-adobe-flex-is-it-just-flash-ii http://stackoverflow.com/questions/554899/getting-started-with-flex-3-ui-actionscript-programming http://stackoverflow.com/questions/2123105/how-to-learn-flex

    Read the article

  • Puting contact number into field

    - by dfilkovi
    I have this code that has one button that let's me choose an entry from contacts, and passes that choesn contact to onActivityResult function. My question is how do I select data of that single contact when all that is passed is an Intent in data variable. That data variable, if converted to string shows something like "dat: content://contacts/people/4" so I see that selected contact is somehow passed, but what now? How to get that data? And also all I found by googling was examples with deprecated class People, so I don't know how too use new classes. Please help. Thank you. public class HelloAndroid extends Activity { private static final int CONTACT_ACTIVITY = 100; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final Button contactButton = (Button) findViewById(R.id.pick_contact_button); contactButton.setOnClickListener(new OnClickListener() { public void onClick(View v) { Uri uri = Uri.parse("content://contacts/people"); Intent contacts_intent = new Intent(Intent.ACTION_PICK, uri); startActivityForResult(contacts_intent, CONTACT_ACTIVITY); } }); } public void onActivityResult(int requestCode, int resultCode, Intent data){ super.onActivityResult(requestCode, resultCode, data); switch(requestCode){ case(CONTACT_ACTIVITY): { if(resultCode == Activity.RESULT_OK) { alertText(data.toString()); } break; } } } }

    Read the article

  • Login with Kohana auth module - what am I doing wrong?

    - by keithjgrant
    I'm trying to login with the following controller action, but my login attempt keeps failing (I get the 'invalid username and/or password' message). What am I doing wrong? I also tried the other method given in the examples in the auth documentation, Auth::instance()->login($user->username, $form->password);, but I get the same result. Kohana version is 2.3.4. public function login() { $auth = Auth::instance(); if ($auth->logged_in()) { url::redirect('/account/summary'); } $view = new View('login'); $view->username = ''; $view->password = ''; $post = $this->input->post(); $form = new Validation($post); $form->pre_filter('trim', 'username') ->pre_filter('trim', 'password') ->add_rules('username', 'required'); $failed = false; if (!empty($post) && $form->validate()) { $login = array( 'username' => $form->username, 'password' => $form->password, ); if (ORM::factory('user')->login($login)) { url::redirect('/accounts/summary'); } else { $view->username = $form->username; $view->message = in_array('required', $form->errors()) ? 'Username and password are required.' : 'Invalid username and/or password.'; } } $view->render(true); }

    Read the article

  • Combining aggregate functions in an (ANSI) SQL statement

    - by morpheous
    I have aggregate functions foo(), foobar(), fredstats(), barneystats() I want to create a domain specific query language (DSQL) above my DB, to facilitate using using a domain language to query the DB. The 'language' comprises of boolean expressions (or more specifically SQL like criteria) which I then 'translate' back into pure (ANSI) SQL and send to the underlying Db. The following lines are examples of what the language statements will look like, and hopefully, it will help further clarify the concept: **Example 1** DQL statement: foobar('yellow') between 1 and 3 and fredstats('weight') > 42 Translation: fetch all rows in an underlying table where computed values for aggregate function foobar() is between 1 and 3 AND computed value for AGG FUNC fredstats() is greater than 42 **Example 2** DQL statement: fredstats('weight') < barneystats('weight') AND foo('fighter') in (9,10,11) AND foobar('green') <> 42 Translation: Fetch all rows where the specified criteria matches **Example 3** DQL statement: foobar('green') / foobar('red') <> 42 Translation: Fetch all rows where the specified criteria matches **Example 4** DQL statement: foobar('green') - foobar('red') >= 42 Translation: Fetch all rows where the specified criteria matches Given the following information: The table upon which the queries above are being executed is called 'tbl' table 'tbl' has the following structure (id int, name varchar(32), weight float) The result set returns only the tbl.id, tbl.name and the names of the aggregate functions as columns in the result set - so for example the foobar() AGG FUNC column will be called foobar in the result set. So for example, the first DQL query will return a result set with the following columns: id, name, foobar, fredstats Given the above, my questions then are: What would be the underlying SQL required for Example1 ? What would be the underlying SQL required for Example3 ? Given an algebraic equation comprising of AGGREGATE functions, Is there a way of generalizing the algorithm needed to generate the required ANSI SQL statement(s)? I am using PostgreSQL as the db, but I would prefer to use ANSI SQL wherever possible.

    Read the article

  • Can any linux API or tool watch for any change in any folder below e.g. /SharedRoot or do I have to

    - by Simon B.
    I have a folder with ~10 000 subfolders. Can any linux API or tool watch for any change in any folder below e.g. /SharedRoot or do I have to setup inotify for each folder? (i.e. I loose if I want to do this for 10k+ folders). I guess yes, since I've already seen examples of this inefficient method, for instance http://twistedmatrix.com/trac/browser/trunk/twisted/internet/inotify.py?rev=28866#L345 My problem: I need to keep folders time-sorted with most recently active "project" up top. When a file changes, each folder above that file should update its last-modified timestamp to match the file. Delays are ok. Opening a file (typically MS Excel) and closing again, its file date can jump up and then down again. For this reason I need to wait until after a file is closed, then queue the folder of that file for checking, and only a while later do I go and look for the newest file in its folder, since the filedate of the triggering file could already be back-dated to its original timestamp by Excel or similar programs. Also in case several files from same folder are used/created, it makes sense to buffer timestamping of that folders' parents to at least get a bunch of updates collapsed into one delayed update. I'm looking for a linux solution. I have some code that can be run on a windows server, most of the queing functionality is here: http://github.com/sesam/FolderdateFollowsFiles/blob/master/FolderdateFollowsFiles/Follower.vb Available API:s The relative of inotify on windows, ReadDirectoryChangesW, can watch a folder and its whole subtree; see bWatchSubtree on http://msdn.microsoft.com/en-us/library/aa365465(VS.85).aspx Samba? Patching samba source is a possibility, but perhaps there are already hooks available? Other possibilities, like client side (various windows versions) and spying on file activities in order to update folders recursively?

    Read the article

  • [iPhone] UIScrollView notifications

    - by ryyst
    Hi, I'm coding an app that works much like Apple's Weather.app: There's a UIPageControl at the bottom and a UIScrollView in the middle of the screen. In my code, I implemented the - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView method to figure out when the user did move to a new page. If they move to a new page, I load the adjacent pages' data, as to make further page-switching faster. (In one of Apple's examples, the - (void)scrollViewDidScroll:(UIScrollView *)sender is used, but that causes my app to shortly hang when loading a new page, so it's not suitable.) That code works very well. I'm using scrollRectToVisible:: to programmatically scroll inside the scrollview when the user clicks the UIPageControl. The problem is that the scrollRectToVisible: doesn't post a notification to the UIScrollViewDelegate when it's done scrolling - so the code responsible for loading adjacent pages never get's called when using the UIPageControl. Is there any way to make the UIScrollView notify its delegate when it gets called by the scrollRectToVisible: method? Or will I have to use threads in order to prevent my app from freezing? Thanks! -- Ry

    Read the article

  • ASP.NET MVC unit testing

    - by Simon Lomax
    Hi, I'm getting started with unit testing and trying to do some TDD. I've read a fair bit about the subject and written a few tests. I just want to know if the following is the right approach. I want to add the usual "contact us" facility on my web site. You know the thing, the user fills out a form with their email address, enters a brief message and hits a button to post the form back. The model binders do their stuff and my action method accepts the posted data as a model. The action method would then parse the model and use smtp to send an email to the web site administrator infoming him/her that somebody filled out the contact form on their site. Now for the question .... In order to test this, would I be right in creating an interface IDeliver that has a method Send(emailAddress, message) to accept the email address and message body. Implement the inteface in a concrete class and let that class deal with smtp stuff and actually send the mail. If I add the inteface as a parameter to my controller constructor I can then use DI and IoC to inject the concrete class into the controller. But when unit testing I can create a fake or mock version of my IDeliver and do assertions on that. The reason I ask is that I've seen other examples of people generating interfaces for SmtpClient and then mocking that. Is there really any need to go that far or am I not understanding this stuff?

    Read the article

  • How do i write tasks? (parallel code)

    - by acidzombie24
    I am impressed with intel thread building blocks. I like how i should write task and not thread code and i like how it works under the hood with my limited understanding (task are in a pool, there wont be 100 threads on 4cores, a task is not guaranteed to run because it isnt on its own thread and may be far into the pool. But it may be run with another related task so you cant do bad things like typical thread unsafe code). I wanted to know more about writing task. I like the 'Task-based Multithreading - How to Program for 100 cores' video here http://www.gdcvault.com/sponsor.php?sponsor_id=1 (currently second last link. WARNING it isnt 'great'). My fav part was 'solving the maze is better done in parallel' which is around the 48min mark (you can click the link on the left side. That part is really all you need to watch if any). However i like to see more code examples and some API of how to write task. Does anyone have a good resource? I have no idea how a class or pieces of code may look after pushing it onto a pool or how weird code may look when you need to make a copy of everything and how much of everything is pushed onto a pool.

    Read the article

  • Oracle output: cursor, file, or very long string?

    - by Klay
    First, the setup: I have a table in an Oracle10g database with spatial columns. I need to be able to pass in a spatial reference so that I can reproject the geometry into an arbitrary coordinate system. Ultimately, I need to compress the results of this projection to a zip file and make it available for download through a Silverlight project. I would really appreciate ideas as to the best way to accomplish this. In the examples below, the SRID is the Spatial reference ID integer used to convert the geometric points into a new coordinate system. In particular, I can see a couple of possibilities. There are many more, but this is an idea of how I'm thinking: a) Pass SRID to a dynamic view -- perform projection, output a cursor -- send cursor to UTL_COMPRESS -- write output to a file (somehow) -- send URL to Silverlight app b) Use SRID to call Oracle function from Silverlight app -- perform projection, output a string -- build strings into a file -- compress file using SharpZipLib library in .NET -- send bytestream back to Silverlight app I've done the first two steps of b), and the conversion of 100 points took about 7 seconds, which is unacceptably slow. I'm hoping it would be faster doing the processing totally in Oracle. If anyone can see potential problems with either way of doing this, or can suggest a better way, it would be very helpful. Thanks!

    Read the article

  • Is JavaEE really portable?

    - by Bozho
    I'm just implementing a JavaEE assignment I was given on an interview. I have some prior experience with EJB, but nothing related to JMS and MDBs. So here's what I find through the numerous examples: application servers bind their topics and queues to different JNDI names - for example topic/queue, jms the activationConfig property is required on JBoss, while in the Sun tutorial it is not. after starting my application, jboss warns me that my topic isn't bound (it isn't actually - I haven't bound it, but I expect it to be bound automatically - in fact, in an example for JBoss 4.0 automatic binding does seem to happen). A suggested solution is to map it in some jboss files or even use jboss-specific annotations. This might be just JBoss, but since it is certified to implement to spec, it appears the spec doesn't specify these these things. And there all the alleged portability vanishes. So I wonder - how come it is claimed that JavaEE is portable and you can take an ear and deploy it on another application server and it magically runs, if such extremely basic things don't appear to be portable at all. P.S. sorry for the rant, but I'm assume I might be doing/getting something wrong, so state your opinions.

    Read the article

  • Protected and Private methods

    - by cabaret
    I'm reading through Beginning Ruby and I'm stuck at the part about private and protected methods. This is a newbie question, I know. I searched through SO for a bit but I couldn't manage to find a clear and newbie-friendly explanation of the difference between private and protected methods. The book gives two examples, the first one for private methods: class Person def initialize(name) set_name(name) end def name @first_name + ' ' + @last_name end private def set_name(name) first_name, last_name = name.split(/\s+/) set_first_name(first_name) set_last_name(last_name) end def set_first_name(name) @first_name = name end def set_last_name(name) @last_name = name end end In this case, if I try p = Person.new("Fred Bloggs") p.set_last_name("Smith") It will tell me that I can't use the set_last_name method, because it's private. All good till there. However, in the other example, they define an age method as protected and when I do fred = Person.new(34) chris = Person.new(25) puts chris.age_difference_with(fred) puts chris.age It gives an error: :20: protected method 'age' called for #<Person:0x1e5f28 @age=25> (NoMethodError) I honestly fail to see the difference between the private and protected methods, it sounds the same to me. Could someone provide me with a clear explanation so I'll never get confused about this again? I'll provide the code for the second example if necessary.

    Read the article

  • Python and Unicode: How everything should be Unicode

    - by A A
    Forgive if this a long a question: I have been programming in Python for around six months. Self taught, starting with the Python tutorial and then SO and then just using Google for stuff. Here is the sad part: No one told me all strings should be Unicode. No, I am not lying or making this up, but where does the tutorial mention it? And most examples also I see just make use of byte strings, instead of Unicode strings. I was just browsing and came across this question on SO, which says how every string in Python should be a Unicode string. This pretty much made me cry! I read that every string in Python 3.0 is Unicode by default, so my questions are for 2.x: Should I do a: print u'Some text' or just print 'Text' ? Everything should be Unicode, does this mean, like say I have a tuple: t = ('First', 'Second'), it should be t = (u'First', u'Second')? I read that I can do a from __future__ import unicode_literals and then every string will be a Unicode string, but should I do this inside a container also? When reading/ writing to a file, I should use the codecs module. Right? Or should I just use the standard way or reading/ writing and encode or decode where required? If I get the string from say raw_input(), should I convert that to Unicode also? What is the common approach to handling all of the above issues in 2.x? The from __future__ import unicode_literals statement? Sorry for being a such a noob, but this changes what I have been doing for a long time and so clearly I am confused.

    Read the article

  • Refreshing Facebook session from an iframe application

    - by zombat
    I've got a Facebook iframe application that is completely external. By this I mean that once a user accesses the canvas URL to load the application, all the links in the iframe app go to my servers, and the canvas page never gets refreshed unless the user navigates to somewhere else on Facebook and comes back (or does a browser refresh). On the initial load of the app where Facebook creates the iframe, I get passed all the usual parameters like fb_sig_user which allows me to create an internal app session based on the facebook user. This app session (which is not the Facebook session, it's my own app session) is all I need to allow the user to work with the app. The problem comes an hour later. If the user leaves the computer, or uses the app for more than an hour, the Facebook session expires. There are some app pages which require fetching friend information, and once the FB session has expired, these pages break, throwing out errors such as "Error: Session key invalid or no longer valid". My question is whether there is a way to refresh the user's Facebook session from within an iframe application to keep it from expiring an hour later. Do any of the API calls do this? Is there a Facebook Connect trick to ping something? Is there any definitive method to keep it alive? I haven't been able to find any examples that specifically address this.

    Read the article

  • MSBuild file for deployment process

    - by Lee Englestone
    I could do with some pointers, code examples or references that may help me do the following in an msbuild file to help speed up the deployment process.. This scenario involves getting a developers 'local' version onto a 'development' server.. Increment a developers local Web Applications Assembly version number Publish a developers local Web Application files somewhere .rar the publsihed files or folder into the format v[IncrementedAssemblyNumber].rar Copy the .rar to somewhere Backup (.rar) the existing live website folder (located elsewhere) in the format Pre_v[IncrementedAssemblyNumber].rar Move the backed up .rar to a /Backup folder. Overwrite the development web files with the published local web files Should be simple for all those MSBUILD Gurus out there. Like I said, answers or 'Good and applicable' links would be much appreciated. Also i'm thinking of getting one of the MSbuild books. From what I can tell there are 2, possibly 3 contenders. I am not using TFS. Can anyone recommend a book for beginning MSBUILD? Ideally from people that have read more than one book on the subject. Cheers, -- Lee

    Read the article

  • How would the 'Model' in a Rails-type webapp be implemented in a functional programming langauge?

    - by ceptorial
    In MVC web development frameworks such as Ruby on Rails, Django, and CakePHP, HTTP requests are routed to controllers, which fetch objects which are usually persisted to a backend database store. These objects represent things like users, blog posts, etc., and often contain logic within their methods for permissions, fetching and/or mutating other objects, validation, etc. These frameworks are all very much object oriented. I've been reading up recently on functional programming and it seems to tout tremendous benefits such as testability, conciseness, modularity, etc. However most of the examples I've seen for functional programming implement trivial functionality like quicksort or the fibonnacci sequence, not complex webapps. I've looked at a few 'functional' web frameworks, and they all seem to implement the view and controller just fine, but largely skip over the whole 'model' and 'persistence' part. (I'm talking more about frameworks like Compojure which are supposed to be purely functional, versus something Lift which conveniently seems to use the OO part of Scala for the model -- but correct me if I'm wrong here.) I haven't seen a good explanation of how functional programming can be used to provide the metaphor that OO programming provides, i.e. tables map to objects, and objects can have methods which provide powerful, encapsulated logic such as permissioning and validation. Also the whole concept of using SQL queries to persist data seems to violate the whole 'side effects' concept. Could someone provide an explanation of how the 'model' layer would be implemented in a functionally programmed web framework?

    Read the article

  • Do fluent interfaces significantly impact runtime performance of a .NET application?

    - by stakx
    I'm currently occupying myself with implementing a fluent interface for an existing technology, which would allow code similar to the following snippet: using (var directory = Open.Directory(@"path\to\some\directory")) { using (var file = Open.File("foobar.html").In(directory)) { // ... } } In order to implement such constructs, classes are needed that accumulate arguments and pass them on to other objects. For example, to implement the Open.File(...).In(...) construct, you would need two classes: // handles 'Open.XXX': public static class OpenPhrase { // handles 'Open.File(XXX)': public static OpenFilePhrase File(string filename) { return new OpenFilePhrase(filename); } // handles 'Open.Directory(XXX)': public static DirectoryObject Directory(string path) { // ... } } // handles 'Open.File(XXX).XXX': public class OpenFilePhrase { internal OpenFilePhrase(string filename) { _filename = filename } // handles 'Open.File(XXX).In(XXX): public FileObject In(DirectoryObject directory) { // ... } private readonly string _filename; } That is, the more constituent parts statements such as the initial examples have, the more objects need to be created for passing on arguments to subsequent objects in the chain until the actual statement can finally execute. Question: I am interested in some opinions: Does a fluent interface which is implemented using the above technique significantly impact the runtime performance of an application that uses it? With runtime performance, I refer to both speed and memory usage aspects. Bear in mind that a potentially large number of temporary, argument-saving objects would have to be created for only very brief timespans, which I assume may put a certain pressure on the garbage collector. If you think there is significant performance impact, do you know of a better way to implement fluent interfaces?

    Read the article

  • Multiple Unpacking Assignment in Python when you don't know the sequence length

    - by doug
    The textbook examples of multiple unpacking assignment are something like: import numpy as NP M = NP.arange(5) a, b, c, d, e = M # so of course, a = 0, b = 1, etc. M = NP.arange(20).reshape(5, 4) # numpy 5x4 array a, b, c, d, e = M # here, a = M[0,:], b = M[1,:], etc. (ie, a single row of M is assigned each to a through e) (My Q is not numpy specfic; indeed, i would prefer a pure python solution.) W/r/t the piece of code i'm looking at now, i see two complications on that straightforward scenario: i usually won't know the shape of M; and i want to unpack a certain number of items (definitely less than all items) and i want to put the remainder into a single container so back to the 5x4 array above, what i would very much like to be able to do is, for instance, assign the first three rows of M to a, b, and c respectively (exactly as above) and the rest of the rows (i have no idea how many there will be, just some positive integer) to a single container, all_the_rest = []. I'm not sure if i have explained this clearly; in any event, if i get feedback i'll promptly edit my Question.

    Read the article

  • Cocoa Drag and Drop, reading back the data

    - by kodai
    Ok, I have a NSOutlineView set up, and I want it to capture PDF's if a pdf is dragged into the NSOutlineView. My first question, I have the following code: [outlineView registerForDraggedTypes:[NSArray arrayWithObjects:NSStringPboardType, NSFilenamesPboardType, nil]]; In all the apple Docs and examples I've seen I've also seen something like MySupportedType being an object registered for dragging. What does this mean? Do I change the code to be: [outlineView registerForDraggedTypes:[NSArray arrayWithObjects:@"pdf", NSStringPboardType, NSFilenamesPboardType, nil]]; Currently I have it set up to recognize drag and drop, and I can even make it spit out the URL of the dragged file once the drag is accepted, however, this leads me to my second question. I want to keep a copy of those PDF's app side. I suppose, and correct me if I'm wrong, that the best way to do this is to grab the data off the clipboard, save it in some persistant store, and that's that. (as apposed to using some sort of copy command and literally copying the file to the app director.) That being said, I'm not sure how to do that. I've the code: - (BOOL)outlineView:(NSOutlineView *)ov acceptDrop:(id <NSDraggingInfo>)info item:(id)item childIndex:(NSInteger)childIndex { NSPasteboard *pboard = [info draggingPasteboard]; NSURL *fileURL; if ( [[pboard types] containsObject:NSURLPboardType] ) { fileURL = [NSURL URLFromPasteboard:pboard]; // Perform operation using the file’s URL } NSData *data = [pboard dataForType:@"NSPasteboardTypePDF"]; But this never actually gets any data. Like I said before, it does get the URL, just not the data. Does anyone have any advise on how to get this going? Thanks so much!

    Read the article

  • How to replace custom IDs in the order of their appearance with a shell script?

    - by Péter Török
    I have a pair of rather large log files with very similar content, except that some identifiers are different between the two. A couple of examples: UnifiedClassLoader3@19518cc | UnifiedClassLoader3@d0357a JBossRMIClassLoader@13c2d7f | JBossRMIClassLoader@191777e That is, wherever the first file contains UnifiedClassLoader3@19518cc, the second contains UnifiedClassLoader3@d0357a, and so on. I want to replace these with identical IDs so that I can spot the really important differences between the two files. I.e. I want to replace all occurrences of both UnifiedClassLoader3@19518cc in file1 and UnifiedClassLoader3@d0357a in file2 with UnifiedClassLoader3@1; all occurrences of both JBossRMIClassLoader@13c2d7f in file1 and JBossRMIClassLoader@191777e in file2 with JBossRMIClassLoader@2 etc. Using the Cygwin shell, so far I managed to list all different identifiers occurring in one of the files with grep -o -e 'ClassLoader[0-9]*@[0-9a-f][0-9a-f]*' file1.log | sort | uniq However, now the original order is lost, so I don't know which is the pair of which ID in the other file. With grep -n I can get the line number, so the sort would preserve the order of appearance, but then I can't weed out the duplicate occurrences. Unfortunately grep can not print only the first match of a pattern. I figured I could save the list of identifiers produced by the above command into a file, then iterate over the patterns in the file with grep -n | head -n 1, concatenate the results and sort them again. The result would be something like 2 ClassLoader3@19518cc 137 ClassLoader@13c2d7f 563 ClassLoader3@1267649 ... Then I could (either manually or with sed itself) massage this into a sed command like sed -e 's/ClassLoader3@19518cc/ClassLoader3@2/g' -e 's/ClassLoader@13c2d7f/ClassLoader@137/g' -e 's/ClassLoader3@1267649/ClassLoader3@563/g' file1.log > file1_processed.log and similarly for file2. However, before I start, I would like to verify that my plan is the simplest possible working solution to this. Is there any flaw in this approach? Is there a simpler way?

    Read the article

  • Binding, Prefixes and generated HTML

    - by Vman
    MVC newbie question re binders. Supposing I have two strongly typed partial actions that happen to have a model attributes with the same name, and are rendered in the same containing page i.e.: Class Friend {string Name {get; set ;} DateTime DOB {get; set ;}} Class Foe {string Name {get; set ;} string ReasonForDislike {get; set ;}} Both partials will have a line: <%= Html.TextBoxFor(model => model.Name) %> And associated controller actions: public ActionResult SaveFriend(Friend friend) public ActionResult SaveFoe(Foe foe) My problem is that both will render on my containing page with the same id (of course, bad for lots of reasons). I’m aware of the [Bind] attribute that allows me add a prefix, resulting in code: public ActionResult SaveFriend([Bind(Prefix = “friend”)] Friend friend) <%= Html.TextBox("friend.Name", Model. Name) %> //Boo, no TextBoxFor :( But this still doesn’t cut it. I can just about tolerate the loss of the strongly typed TextBoxFor helpers but I’ve yet to get clientside validation to work with prefixes: I’ve tried: <%= Html.ValidationMessage("friend.Name") %> ...and every other variant I can think of. I seem to need the model to be aware of the prefix in both directions but bind only applies when mapping the inbound request. It seems (to me) a common scenario but I’m struggling to find examples out there. What am I missing! Thanks in advance.

    Read the article

< Previous Page | 213 214 215 216 217 218 219 220 221 222 223 224  | Next Page >