Search Results

Search found 26618 results on 1065 pages for 'amazon instance store'.

Page 831/1065 | < Previous Page | 827 828 829 830 831 832 833 834 835 836 837 838  | Next Page >

  • using jquery in mysql php

    - by JPro
    I am new to using Jquery using mysql and PHP I am using the following code to pull the data. But there is not data or error displayed. JQUERY: <html> <head> <script> function doAjaxPost() { // get the form values var field_a = $("#field_a").val(); $("#loadthisimage").show(); $.ajax({ type: "POST", url: "serverscript.php", data: "ID="+field_a, success: function(resp){ $("#resposnse").html(resp); $("#loadthisimage").hide(); }, error: function(e){ alert('Error: ' + e); } }); } </script> </head> <body> <select id="field_a"> <option value="data_1">data_1</option> <option value="data_2">data_2</option> </select> <input type="button" value="Ajax Request" onClick="doAjaxPost()"> <a href="#" onClick="doAjaxPost()">Here</a> </form> <div id="resposnse"> <img src="ajax-loader.gif" style="display:none" id="loadthisimage"> </div> </body> and now serverscript.php <?php if(isset($_POST['ID'])) { $nm = $_POST['ID']; echo $nm; //insert your code here for the display. mysql_connect("localhost", "root", "pop") or die(mysql_error()); mysql_select_db("JPro") or die(mysql_error()); $result1 = mysql_query("select Name from results where ID = \"$nm\" ") or die(mysql_error()); // store the record of the "example" table into $row while($row1 = mysql_fetch_array( $result1 )) { $tc = $row1['Name']; echo $tc; } } ?>

    Read the article

  • PDO prepare silently fails

    - by Wabbitseason
    I'm experimenting with PHP's session_set_save_handler and I'd like to use a PDO connection to store session data. I have this function as a callback for write actions: function _write($id, $data) { logger('_WRITE ' . $id . ' ' . $data); try { $access = time(); $sql = 'REPLACE INTO sessions SET id=:id, access=:access, data=:data'; logger('This is the last line in this function that appears in the log.'); $stmt = $GLOBALS['db']->prepare($sql); logger('This never gets logged! :('); $stmt->bindParam(':id', $id, PDO::PARAM_STR); $stmt->bindParam(':access', $access, PDO::PARAM_INT); $stmt->bindParam(':data', $data, PDO::PARAM_STR); $stmt->execute(); $stmt->closeCursor(); return true; } catch (PDOException $e) { logger('This is never executed.'); logger($e->getTraceAsString()); } } The first two log messages always show up, but the third one right after $stmt = $GLOBALS['db']->prepare($sql) never makes it to the log file and there's no trace of an exception either. The sessions db table remains empty. The log message from the _close callback is always present. Here's how I connect to the database: $db = new PDO('mysql:host=' . DBHOST . ';dbname=' . DBNAME, DBUSER, DBPASS); $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); I have PHP 5.2.10. I tried to simply run $GLOBALS['db']->exec($sql) with a "manually prepared" $sql content, but it still failed silently. The query itself is all right I was able to execute it via the db console.

    Read the article

  • Redirect uploaded files to another server, using nginx

    - by Serg ikS
    I am creating a web service of scheduled posts to some soc. network.Need help dealing with file uploads under high traffic. Process overview: User uploads files to SomeServer (not mine). SomeServer then responds with a JSON string. My web app should store that JSON response. Opt. 1 — Save, cURL POST, delete tmp The stupid way I made it work: User uploads files to MyWebApp; MyWebApp cURL's the file further to SomeServer, getting the response. Opt.2 — JS magic The smart way it could be perfect: User uploads the file directly to SomeServer, from within an iFrame; MyWebApp gets the response through JavaScript. But this is(?) impossible due to the 'Same Origin Policy', isn't it? Opt. 3 — nginx proxying? The better way for a production server: User uploads files to MyWebApp; nginx intercepts the file uploads and sends them directly to the SomeServer; JSON response is also intercepted by nginx and processed by MyWebApp. Does this make any sense, and what would be the nginx config for, say, /fileupload Location to proxy it to SomeServer ?

    Read the article

  • De-normalization alternative to specific MYSQL problem?

    - by Booker
    I am facing quite a specific optimization problem. I currently have 4 normalized tables of data. Every second, possibly thousands of users will pull down up-to-date info from these tables using AJAX. The thing is that I can predict relatively easily which subset of data they need... The most recent 100 or so entries in those 4 normalized tables. I have been researching de-normalization... but feel that perhaps there is an easier solution. I was thinking that I could somehow every second run one sql query to condense the needed info, store it in a temp cached table and then have all of the user queries just draw from this. This will allow the complex join of 4 tables to only be run once, and then from there the users just need to do a simple lookup from the cached table. I really don't know if this is feasible. Comments on this or any other suggestions would be much appreciated. Thanks!

    Read the article

  • Data Structures for Junior Java Developer

    - by user1639637
    Ok,still learning Arrays. I wrote this code which fills the array named "rand" with random numbers between 0 and 1( exclusive). I want to start learning Complexity. the For loop executes n times (100 times) ,every time it takes O(1) time,so the worse case scenario is O(n),am I right? Also,I used ArrayList to store the 100 elements and I imported "Collections" and used Collections.sort() method to sort the elements. import java.util.Arrays; public class random { public static void main(String args[]) { double[] rand=new double[10]; for(int i=0;i<rand.length;i++) { rand[i]=(double) Math.random(); System.out.println(rand[i]); } Arrays.sort(rand); System.out.println(Arrays.toString(rand)); } } ArrayList: import java.util.ArrayList; import java.util.Collections; public class random { public static void main(String args[]) { ArrayList<Double> MyArrayList=new ArrayList<Double>(); for(int i=0;i<100;i++) { MyArrayList.add(Math.random()); } Collections.sort(MyArrayList); for(int j=0;j<MyArrayList.size();j++) { System.out.println(MyArrayList.get(j)); } } }

    Read the article

  • what is the point of heterogenous arrays?

    - by aharon
    I know that more-dynamic-than-Java languages, like Python and Ruby, often allow you to place objects of mixed types in arrays, like so: ["hello", 120, ["world"]] What I don't understand is why you would ever use a feature like this. If I want to store heterogenous data in Java, I'll usually create an object for it. For example, say a User has int ID and String name. While I see that in Python/Ruby/PHP you could do something like this: [["John Smith", 000], ["Smith John", 001], ...] this seems a bit less safe/OO than creating a class User with attributes ID and name and then having your array: [<User: name="John Smith", id=000>, <User: name="Smith John", id=001>, ...] where those <User ...> things represent User objects. Is there reason to use the former over the latter in languages that support it? Or is there some bigger reason to use heterogenous arrays? N.B. I am not talking about arrays that include different objects that all implement the same interface or inherit from the same parent, e.g.: class Square extends Shape class Triangle extends Shape [new Square(), new Triangle()] because that is, to the programmer at least, still a homogenous array as you'll be doing the same thing with each shape (e.g., calling the draw() method), only the methods commonly defined between the two.

    Read the article

  • reinitializing javascript object's properties

    - by Pino
    In my Javascript drag and drop build app, a variety of buildings can be built. The specific characteristics of these are all saved in one object, like var buildings = { house: ['#07DA21',12,12,0,20], bank: ['#E7DFF2',16,16,0,3], stadium: ['#000000',12,12,0,1], townhall: ['#2082A8',20,8,0,1], etcetera } So every building has a number of characteristics, like color, size, look which can be called as buildings[townhall][0] (referring to the color). The object changes as the user changes things. When clicking 'reset' however, the whole object should be reset to its initial settings again to start over, but I have no idea how to do that. For normal objects it is something like. function building() {} var building = new building(); delete building; var building2 = new building(); You can easily delete and remake it, so the properties are reset. But my object is automatically initialized. Is there a way to turn my object into something that can be deleted and newly created, without making it very complicating, or a better way to store this information?

    Read the article

  • SQL Distinct keyword in assignment statement

    - by Brandi
    I have a query that works: DECLARE @ProductID int SET @ProductID = '1234' SELECT DISTINCT TOP 12 a.ProductID FROM A a WHERE a.CategoryID IN (SELECT b.CategoryID FROM B b WHERE b.ProductID = @ProductID) AND a.ProductID != @ProductID It returns a list of 12 product numbers, all unique. I need to store these results in a variable, comma separated, because that's what 3rd party stored procedure needs. So I have this: DECLARE @ProductID int DECLARE @relatedprods varchar(8000) SET @ProductID = '1234' SET @relatedprods = '' SELECT TOP 12 @relatedprods = @relatedprods + CONVERT(VARCHAR(20), a.ProductID) + ', ' FROM A a WHERE a.CategoryID IN (SELECT b.CategoryID FROM B b WHERE B.ProductID = @ProductID) AND a.ProductID != @ProductID SELECT @relatedprods Now, none of these are distinct, but it is returning 12 rows. Now I add the 'distinct' back in, like in the first query: DECLARE @ProductID int DECLARE @relatedprods varchar(8000) SET @ProductID = '1234' SET @relatedprods = '' SELECT DISTINCT TOP 12 @relatedprods = @relatedprods + CONVERT(VARCHAR(20), a.ProductID) + ', ' FROM A a WHERE a.CategoryID IN (SELECT b.CategoryID FROM B b WHERE B.ProductID = @ProductID) AND a.ProductID != @ProductID SELECT @relatedprods Only one product is returned in the comma separated list! Does 'distinct' not work in assignment statements? What did I do wrong? Or is there a way to get around this? Thanks in advance!

    Read the article

  • Time delay an external RSS feed

    - by x3ja
    I subscribe to a number of RSS feeds, mostly from within my own timezone (UK: currently GMT+1, a.k.a BST). However I'm also interested in news from New Zealand (currently GMT+12). My problem is caused by my addiction to needing to keep my unread count at, or near, zero. When I load up my RSS reader in the mornings it has gathered all the NZ news at once (normally around 100 items) and I feel compelled either to read them all or to mark them all as read to feed my need for zero-unread-count. I figured a good solution to this would be to time delay the RSS feed somehow, so I would be drip-fed the stories at their time +12 hours, so I could read them through the day as they come in. So my question (or, rather, questions): Does such a thing exist currently & what is it? (no point reworking the wheel) If not: What would be the best way to approach doing this myself? I have access to a Linux web server on which I can run scripts, create databases, store files etc, so there should be a way... I'm most conversant in perl and have done a little fiddling with XML within that, so would naturally process ... or is there some simpler way to do it that I'm missing?

    Read the article

  • 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 there a way to customize how the value for a custom Model Field is displayed in a template?

    - by Jordan Reiter
    I am storing dates as an integer field in the format YYYYMMDD, where month or day is optional. I have the following function for formatting the number: def flexibledateformat(value): import datetime, re try: value = str(int(value)) except: return None match = re.match(r'(\d{4})(\d\d)(\d\d)$',str(value)) if match: year_val, month_val, day_val = [int(v) for v in match.groups()] if day_val: return datetime.datetime.strftime(datetime.date(year_val,month_val,day_val),'%b %e, %Y') elif month_val: return datetime.datetime.strftime(datetime.date(year_val,month_val,1),'%B %Y') else: return str(year_val) Which results in the following outputs: >>> flexibledateformat(20100415) 'Apr 15, 2010' >>> flexibledateformat(20100400) 'April 2010' >>> flexibledateformat(20100000) '2010' So I'm wondering if there's a function I can add under the model field class that would automatically call flexibledateformat. So if there's a record r = DataRecord(name='foo',date=20100400) when processed in the form the value would be 20100400 but when output in a template using {{ r.date }} it shows up as "April 2010". Further clarification I do normally use datetime for storing date/time values. In this specific case, I need to record non-specific dates: "x happened in 2009", "y happened sometime in June 1996". The easiest way to do this while still preserving most of the functionality of a date field, including sorting and filtering, is by using an integer in the format of yyyymmdd. That is why I am using an IntegerField instead of a DateTimeField. This is what I would like to happen: I store what I call a "Flexible Date" in a FlexibleDateField as an integer with the format yyyymmdd. I render a form that includes a FlexibleDateField, and the value remains an integer so that functions necessary for validating it and rendering it in widgets work correctly. I call it in a template, as in {{ object.flexibledate }} and it is formatted according to the flexibledateformat rules: 20100416 - April 16, 2010; 20100400 - April 2010; 20100000 - 2010. This also applies when I'm not calling it directly, such as when it's used as a header in admin (http://example.org/admin/app_name/model_name/). I'm not aware if these specific things are possible.

    Read the article

  • Some Async Socket Code - Help with Garbage Collection?

    - by divinci
    Hi all, I think this question is really about my understanding of Garbage collection and variable references. But I will go ahead and throw out some code for you to look at. // Please note do not use this code for async sockets, just to highlight my question // SocketTransport // This is a simple wrapper class that is used as the 'state' object // when performing Async Socket Reads/Writes public class SocketTransport { public Socket Socket; public byte[] Buffer; public SocketTransport(Socket socket, byte[] buffer) { this.Socket = socket; this.Buffer = buffer; } } // Entry point - creates a SocketTransport, then passes it as the state // object when Asyncly reading from the socket. public void ReadOne(Socket socket) { SocketTransport socketTransport_One = new SocketTransport(socket, new byte[10]); socketTransport_One.Socket.BeginRecieve ( socketTransport_One.Buffer, // Buffer to store data 0, // Buffer offset 10, // Read Length SocketFlags.None // SocketFlags new AsyncCallback(OnReadOne), // Callback when BeginRead completes socketTransport_One // 'state' object to pass to Callback. ); } public void OnReadOne(IAsyncResult ar) { SocketTransport socketTransport_One = ar.asyncState as SocketTransport; ProcessReadOneBuffer(socketTransport_One.Buffer); // Do processing // New Read // Create another! SocketTransport (what happens to first one?) SocketTransport socketTransport_Two = new SocketTransport(socket, new byte[10]); socketTransport_Two.Socket.BeginRecieve ( socketTransport_One.Buffer, 0, 10, SocketFlags.None new AsyncCallback(OnReadTwo), socketTransport_Two ); } public void OnReadTwo(IAsyncResult ar) { SocketTransport socketTransport_Two = ar.asyncState as SocketTransport; .............. So my question is: The first SocketTransport to be created (socketTransport_One) has a strong reference to a Socket object (lets call is ~SocketA~). Once the async read is completed, a new SocketTransport object is created (socketTransport_Two) also with a strong reference to ~SocketA~. Q1. Will socketTransport_One be collected by the garbage collector when method OnReadOne exits? Even though it still contains a strong reference to ~SocketA~ Thanks all!

    Read the article

  • CakePHP: Custom Function in bootstrap that uses $ajax->link not working

    - by nekko
    Hello I have two questions: (1) Is it best practice to create global custom functions in the bootstrap file? Is there a better place to store them? (2) I am unable use the following line of code in my custom function located in my bootstrap.php file: $url = $ajax->link ( 'Delete', array ('controller' => 'events', 'action' => 'delete', 22 ), array ('update' => 'event' ), 'Do you want to delete this event?' ); echo $url; I receive the following error: Notice (8): Undefined variable: ajax [APP\config\bootstrap.php, line 271] Code } function testAjax () { $url = $ajax->link ( 'Delete', array ('controller' => 'events', 'action' => 'delete', 22 ), array ('update' => 'event' ), 'Do you want to delete this event?' ); testAjax - APP\config\bootstrap.php, line 271 include - APP\views\event\queue.ctp, line 19 View::_render() - CORE\cake\libs\view\view.php, line 649 View::render() - CORE\cake\libs\view\view.php, line 372 Controller::render() - CORE\cake\libs\controller\controller.php, line 766 Dispatcher::_invoke() - CORE\cake\dispatcher.php, line 211 Dispatcher::dispatch() - CORE\cake\dispatcher.php, line 181 [main] - APP\webroot\index.php, line 91 However it works as intended if I place that same code in my view: <a onclick=" event.returnValue = false; return false;" id="link1656170149" href="/shout/events/delete/22">Delete</a> Please help :) Thanks in advance!!

    Read the article

  • Combinatorial optimisation of a distance metric

    - by Jose
    I have a set of trajectories, made up of points along the trajectory, and with the coordinates associated with each point. I store these in a 3d array ( trajectory, point, param). I want to find the set of r trajectories that have the maximum accumulated distance between the possible pairwise combinations of these trajectories. My first attempt, which I think is working looks like this: max_dist = 0 for h in itertools.combinations ( xrange(num_traj), r): for (m,l) in itertools.combinations (h, 2): accum = 0. for ( i, j ) in itertools.izip ( range(k), range(k) ): A = [ (my_mat[m, i, z] - my_mat[l, j, z])**2 \ for z in xrange(k) ] A = numpy.array( numpy.sqrt (A) ).sum() accum += A if max_dist < accum: selected_trajectories = h This takes forever, as num_traj can be around 500-1000, and r can be around 5-20. k is arbitrary, but can typically be up to 50. Trying to be super-clever, I have put everything into two nested list comprehensions, making heavy use of itertools: chunk = [[ numpy.sqrt((my_mat[m, i, :] - my_mat[l, j, :])**2).sum() \ for ((m,l),i,j) in \ itertools.product ( itertools.combinations(h,2), range(k), range(k)) ]\ for h in itertools.combinations(range(num_traj), r) ] Apart from being quite unreadable (!!!), it is also taking a long time. Can anyone suggest any ways to improve on this?

    Read the article

  • Can I remove duplicating events in EventAggregator?

    - by Mcad001
    Hi, I have a quite simple scenario that I cannot get to work correctly. I have 2 views, CarView and CarWindowView (childwindow) with corresponding ViewModels. In my CarView I have an EditButton that that opens CarWindowView (childwindow) where I can edit the Car object fields. My problem is that the DisplayModule method in my CarWindowView ViewModel is getting called too many times...When I push the edit button first time its getting called once, the second time its getting called twince, the third time its getting called 3 times and so fort... ! CarView ViewModel constructor: Public Sub New(ByVal eventAggregator As IEventAggregator, ByVal con As IUnityContainer, ByVal mgr As ICarManager, ByVal CarService As ICarService) _Container = con _CarManager = mgr _EventAggregator = eventAggregator 'Create the DelegateCommands NewBtnClick = New DelegateCommand(Of Object)(AddressOf HandleNewCarBtnClick) EditBtnClick = New DelegateCommand(Of Object)(AddressOf HandleEditCarBtnClick) End Sub CarView ViewModel HandleEditCarBtnClick method: Private Sub HandleEditCarBtnClick() Dim view = New CarWindowView Dim viewModel = _Container.Resolve(Of CarWindowViewModel)() viewModel.CurrentDomainContext = DomainContext viewModel.CurrentItem = CurrentItem viewModel.IsEnabled = False view.ApplyModel(viewModel) view.Show() _EventAggregator.GetEvent(Of CarCollectionEvent)().Publish(EditObject) End Sub CarWindowView ViewModel constructor: Public Sub New(ByVal eventAggregator As IEventAggregator, ByVal con As IUnityContainer, ByVal mgr As ICarManager, ByVal CarService As ICarService) _Container = con _CarManager = mgr _EventAggregator = eventAggregator _EventAggregator.GetEvent(Of CarCollectionEvent).Subscribe(AddressOf DisplayModule) End Sub CarWindowView ViewModel DisplayModule method (this is the method getting called too many times): Public Sub DisplayModule(ByVal param As String) If param = EditObject Then IsInEditMode = True ' Logic removed for display reasons here. This logic breaks because it's called too many times. End If End Sub So, I cannot understand how I can only have the EventAggregator to store just the one single click, and not all my click on the Edit button. Sorry if this is not to well explained! Help appreciated!!

    Read the article

  • Data of the web services in a RSS

    - by vymz
    I only have the .wsdl and I want to put the data that the web services return in the RSS. And in a web page of SAP, I can only upload RSS, so I need put the information of the web services in the RSS For example, I put the information manually(name and total value) in the fields <title> and <descripcion>, these data are extracted from the web services. But sometimes I don´t know how much information brings the web service. Also, I know that RSS is not to store information such as web services. <?xml version="1.0" encoding="UTF-8" ?> <rss version="2.0"> <channel> <title>Test RSS</title> <link>http://solutions.com</link> <description>RSS</description> <item> <title>Luiz</title> <link>http://www.solutions.com/prueba1</link> <description>10</description> </item> <item> <title>Clodoaldo</title> <link>http://www.solutions.com/prueba2</link> <description>5</description> </item>

    Read the article

  • What is the most efficient/elegant way to parse a flat table into a tree?

    - by Tomalak
    Assume you have a flat table that stores an ordered tree hierarchy: Id Name ParentId Order 1 'Node 1' 0 10 2 'Node 1.1' 1 10 3 'Node 2' 0 20 4 'Node 1.1.1' 2 10 5 'Node 2.1' 3 10 6 'Node 1.2' 1 20 What minimalistic approach would you use to output that to HTML (or text, for that matter) as a correctly ordered, correctly intended tree? Assume further you only have basic data structures (arrays and hashmaps), no fancy objects with parent/children references, no ORM, no framework, just your two hands. The table is represented as a result set, which can be accessed randomly. Pseudo code or plain English is okay, this is purely a conceptional question. Bonus question: Is there a fundamentally better way to store a tree structure like this in a RDBMS? EDITS AND ADDITIONS To answer one commenter's (Mark Bessey's) question: A root node is not necessary, because it is never going to be displayed anyway. ParentId = 0 is the convention to express "these are top level". The Order column defines how nodes with the same parent are going to be sorted. The "result set" I spoke of can be pictured as an array of hashmaps (to stay in that terminology). For my example was meant to be already there. Some answers go the extra mile and construct it first, but thats okay. The tree can be arbitrarily deep. Each node can have N children. I did not exactly have a "millions of entries" tree in mind, though. Don't mistake my choice of node naming ('Node 1.1.1') for something to rely on. The nodes could equally well be called 'Frank' or 'Bob', no naming structure is implied, this was merely to make it readable. I have posted my own solution so you guys can pull it to pieces.

    Read the article

  • Why is my PHP string being converted to 1?

    - by animuson
    Ok, so here's the quick rundown. I have a function to generate the page numbers. This: <?php die($ani->e->tmpl->pages("/archive", 1, 15, 1, true)); ?> will output Single Page like expected. But this: <?php $page_numbers = $ani->e->tmpl->pages("/archive", 1, 15, 1, true); ?> <?= $page_numbers ?> will output a simple 1 to the page. Why is it getting converted to a 1? I would expect it to store the 'Single Page' string to the page_numbers variable and then output it (like an echo) exactly the same. EDIT: Running a var_dump($page_numbers) returns int(1)... Here is the entire function in context: <?php // other functions... function show_list() { global $ani; $page_numbers = $ani->e->tmpl->pages("/archive", 1, 15, 1, true); ob_start(); ?> <!-- content:start --> <?php $archive_result = $ani->e->db->build(array("select" => "*", "from" => "animuson_archive", "orderby" => "0-time", "limit" => 15)); while ($archive = $ani->e->db->fetch($archive_result)) { ?> <h2><a href="/archive/article/<?= $archive['aid'] ?>/<?= $archive['title_nice'] ?>"><?= $archive['title'] ?></a></h2> <!-- breaker --> <?php } ?> <?= var_dump($page_numbers) ?> <!-- content:stop --> <?php $ani->e->tmpl->process("box", ob_get_clean()); } // other functions... ?>

    Read the article

  • How is a referencing environment generally implemented for closures?

    - by Alexandr Kurilin
    Let's say I have a statically/lexically scoped language with deep binding and I create a closure. The closure will consist of the statements I want executed plus the so called referencing environment, or, to quote this post, the collection of variables which can be used. What does this referencing environment actually look like implementation-wise? I was recently reading about ObjectiveC's implementation of blocks, and the author suggests that behind the scenes you get a copy of all of the variables on the stack and also of all the references to heap objects. The explanation claims that you get a "snapshot" of the referencing environment at the point in time of the closure's creation. Is that more or less what happens, or did I misread that? Is anything done to "freeze" a separate copy of the heap objects, or is it safe to assume that if they get modified between closure creation and the closure executing, the closure will no longer be operating on the original version of the object? If indeed there's copying being made, are there memory usage considerations in situations where one might want to create plenty of closures and store them somewhere? I think that misunderstanding of some of these concepts might lead to tricky issues like the ones Eric Lippert mentions in this blog post. It's interesting because you'd think that it wouldn't make sense to keep a reference to a value type that might be gone by the time the closure is called, but I'm guessing that in C# the compiler will figure out that the variable is needed later and put it into the heap instead. It seems that in most memory-managed languages everything is a reference and thus ObjectiveC is a somewhat unique situation with having to deal with copying what's on the stack.

    Read the article

  • What MS technology to use for HTTP service returning XML?

    - by Borek
    I need to create a service that: accepts HTTP requests (with query string or HTTP POST parameters) does some processing on the requests (checking if the request is valid, authentication etc.) reads data from a custom store (another HTTP call in our case) returns the result as custom XML (defined with XSD) I'm trying to think of various MS technologies that could help me and how good they would be for this scenario (pretty standard one I guess). The tasks above are relatively separate, this is what comes to mind: HTTP front-end: ASP.NET Web Forms ASP.NET MVC (seems more appropriate here as I won't need server controls, view state etc.) WCF? Don't know much about it or how well it would suit my task. Custom logic on the server: this will probably be a generic C# code in all cases (sometimes "plugged into" or called from MVC controllers or some equivalent place in other technologies) Reading data from internal data stores: As said, this is another HTTP server in our case. Options that come to mind: Just read the data using something like WebClient (Just theoretically) implement a LINQ provider (Just even more theoretically) implement an EF provider Output the data as custom XML: Linq2XML Serialization? Is it flexible enough? Does WCF provide some tools for this? Some "OXM" - Object/XML mapper if there is something like that for .NET I may be wrong in many of my assumptions, this is just a quick list that comes to mind after a quick research. Some general notes / questions: Testing is important Solution with a clear domain model would be much preferred over the one without Can Entity Framework actually help somewhere in my scenario? If so, where and how? Would WCF be an appropriate technology for this? I don't know much about it.

    Read the article

  • When does an ARM7 processor increase its PC register?

    - by Summer_More_More_Tea
    Hi everyone: I'm thinking about this question for a time: when does an ARM7(with 3 pipelines) processor increase its PC register. I originally thought that after an instruction has been executed, the processor first check is there any exception in the last execution, then increase PC by 2 or 4 depending on current state. If an exception occur, ARM7 will change its running mode, store PC in the LR of current mode and begin to process current exception without modifying the PC register. But it make no sense when analyzing returning instructions. I can not work out why PC will be assigned LR when returning from an undefined-instruction-exception while LR-4 from prefetch-abort-exception, don't both of these exceptions happened at the decoding state? What's more, according to my textbook, PC will always be assigned LR-4 when returning from prefetch-abort-exception no matter what state the processor is(ARM or Thumb) before exception occurs. However, I think PC should be assigned LR-2 if the original state is Thumb, since a Thumb-instruction is 2 bytes long instead of 4 bytes which an ARM-instruction holds, and we just wanna roll-back an instruction in current state. Is there any flaws in my reasoning or something wrong with the textbook. Seems a long question. I really hope anyone can help me get the right answer. Thanks in advance.

    Read the article

  • Trouble bringing a Blackberry App to Foreground

    - by Luis Armando
    I have an app that is listening in background and when the user clicks "send" it displays a dialogue. However I need to bring my app to foreground so the user answers some questions before letting the message go. but I haven't been able to do this, this is the code in my SendListener: SendListener sl = new SendListener(){ public boolean sendMessage(Message msg){ Dialog myDialog = new Dialog(Dialog.D_OK, "message from within SendListener", Dialog.OK,Bitmap.getPredefinedBitmap(Bitmap.EXCLAMATION), Dialog.GLOBAL_STATUS) { //Override inHolster to prevent the Dialog from being dismissed //when a user holsters their BlackBerry. This can //cause a deadlock situation as the Messages //application tries to save a draft of the message //while the SendListener is waiting for the user to //dismiss the Dialog. public void inHolster() { } }; //Obtain the application triggering the SendListener. Application currentApp = Application.getApplication(); //Detect if the application is a UiApplication (has a GUI). if( currentApp instanceof UiApplication ) { //The sendMessage method is being triggered from //within a UiApplication. //Display the dialog using is show method. myDialog.show(); App.requestForeground(); } else { //The sendMessage method is being triggered from // within an application (background application). Ui.getUiEngine().pushGlobalScreen( myDialog, 1, UiEngine.GLOBAL_MODAL ); } return true; } }; store.addSendListener(sl); App is an object I created above: Application App = Application.getApplication(); I have also tried to invoke the App to foreground using its processID but so far no luck.

    Read the article

  • Java application design question

    - by ring bearer
    I have a hobby project, which is basically to maintain 'todo' tasks in the way I like. One task can be described as: public class TodoItem { private String subject; private Date dueBy; private Date startBy; private Priority priority; private String category; private Status status; private String notes; } As you can imagine I would have 1000s of todo items at a given time. What is the best strategy to store a todo item? (currently on an XML file) such that all the items are loaded quickly up on app start up(the application shows kind of a dashboard of all the items at start up)? What is the best way to design its back-end so that it can be ported to Android/or a J2ME based phone? Currently this is done using Java Swing. What should I concentrate on so that it works efficiently on a device where memory is limited? The application throws open a form to enter new todo task. For now, I would like to save the newly added task to my-todos.xml once the user presses "save" button. What are the common ways to append such a change to an existing XML file?(note that I don't want to read the whole file again and then persist)

    Read the article

  • SQL, MVC, Entity Framework

    - by Anthony
    Hi Im using the above technologies and have ran into what I presume is a design issue I have made. I have an Artwork table in my DB and have been able to add art (I now think of these as Digital Products) to a shopping cart + CartLine table fine. The system I have that adds art to galleries and user accounts etc works fine. Now the client wants to sell T-shirts, Mugs and Pens etc, 'HardwareProducts' so I have created a 'HardwareProducts' table. Now I have two different product types in two tables. I use GUID's as the PK's in both the HardwareProducts table and Artwork table. When a customer adds an item to their cart I store the GUID in the ProductID column in the CartItems table. The issue is the database will not know which table to reference when I bring the LineItem object up through my ORM to the front end. In OOP I can see how you would have a base class of Product, and then a DigitalProduct class and HardwareProduct class drived from it, but how do you model this in SQL Server and the Entity Framework please, or is there another way?

    Read the article

  • How do I use IPTC/EXIF metadata to categorise photos?

    - by kbro
    Many photo viewing and editing applications allow you to examine and change EXIF and IPTC data in JPEG and other image files. For example, I can see things like shutter speed, aperture and orientation in the picture files that come off my Canon A430. There are many, many name/value pairs in all this metadata. But... What do I do if I want to store some data that doesn't have a build-in field name. Let's say I'm photographing an athletics competition and I want to tag every photo with the competitor's bib number. Can I create a "bib_number" field and assign it a values of "0001", "5478", "8124" etc, and then search for all photos with bib_number="5478"? I've spent a few hours searching and the best I can come up with is to put this custom information in the "keywords" field but this isn't quite what I'm after. With this socution I'd have to craft a query like "keywords contains bib_number_5478" whereas what I want it "bib_number is 5478". So do the EXIF and/or IPTC standards allow addtional user-defined field names? Thanks Kev

    Read the article

< Previous Page | 827 828 829 830 831 832 833 834 835 836 837 838  | Next Page >