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  • Assistance with Lua functions

    - by Josh
    As noted before, I'm relatively new to lua, but again, I learn quick. The last time I got help here, it helped me immensely, and I was able to write a better script. Now I've come to another question that I think will make my life a bit easier. I have no clue what I'm doing with functions, but I'm hoping there is a way to do what I want to do here. Below, you'll see an example of code I have to do to strip down some unneeded elements. Yeah, I realize it's not efficient in the least, so if anyone else has a better idea of how to make it much more efficient, I'm all ears. What I would like to do is create a function with it so that I can strip down whatever variable with a simple call of it (like stripdown(winds)). I appreciate any help that is offered, and any lessons given. Thanks! winds = string.gsub(winds,"%b<>","") winds = string.gsub(winds,"%c"," ") winds = string.gsub(winds," "," ") winds = string.gsub(winds," "," ") winds = string.gsub(winds,"^%s*(.-)%s*$", "%1)") winds = string.gsub(winds,"&nbsp;","") winds = string.gsub(winds,"/ ", "(") Josh

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  • Hidden div height

    - by fudgey
    Ok, I was going to answer someone's question here on SO about why their script wasn't working. They loaded content into a hidden div, then got the height so they could animate the wrapping div. But I always try to test the code I provide. So I made this demo to prove it to them. So, umm, have I entered the twilight zone or am I dreaming right now? pinches self OUCH! I tried that demo in Firefox, IE and Chrome and both methods return the same value. Firebug says zero! I rebooted my computer and I even changed the code a bit (removed the height function) and tried it with jQuery 1.3.2 and it still worked! I know hidden elements USED to return a zero value. Even this SO Answer is giving the advice I would have! So I guess my question is... did I miss something or are we giving bad advice?

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  • problem configure JBoss to work with JNDI

    - by Spiderman
    I am trying to bind connection to the DB using JNDI in my application that runs on JBoss. I did the following: I created the datasource file oracle-ds.xml filled it with the relevant xml elements: <datasources> <local-tx-datasource> <jndi-name>bilby</jndi-name> ... </local-tx-datasource> </datasources> and put it in the folder \server\default\deploy Added the relevant oracle jar file than in my application I performed: JndiObjectFactoryBean factory = new JndiObjectFactoryBean(); factory.setJndiName("bilby"); try{ factory.afterPropertiesSet(); dataSource = factory.getObject(); } catch(NamingException ne) { ne.printStackTrace(); } and this cause the error: javax.naming.NameNotFoundException: bilby not bound then in the output after this error occured I saw the line: 18:37:56,560 INFO [ConnectionFactoryBindingService] Bound ConnectionManager 'jb oss.jca:service=DataSourceBinding,name=bilby' to JNDI name 'java:bilby' So what is my configuration problem? I think that it may be that JBoss first loads and runs the .war file of my application and only then it loads the oracle-ds.xml that contain my data-source definition. The problem is that they are both located in the same folder. Is there a way to define priority of loading them, or maybe this is not the problem at all. Any idea?

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  • WPF, notify a child in the element tree about an event in a parent

    - by jester
    I am developing a WPF app and I want an event in a parent to be notified to several of its children in the element tree, so that each of them can take an action accordingly. I know that a custom RoutedEvent can be used to signal in the other direction from a child to one of its ancestors by bubbling the event upwards, so that any of the ancestor elements can handle the event. What I want is the children to be notified about an event in the parent and they handle them appropriately. What is the best strategy to achieve this? EDIT: Clarifying the comments : Say I have a parent UserControl. It has a TabControl and its contents are several nested child UserControls. Now consider a scenario where I want the TabControl.SelectionChanged() event to cause some changes in each of the child UserControl. How to achieve this? (The contents of each tab is a UserControl which themselves may contain another few levels of children UserControls. I want the UserControl in the bottom level to know about the SelectionChanged() event and respond accordingly).

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  • LINQ to XML Query Help

    - by cw
    Hello, I am trying to get a "diff" of 2 xml documents and end up with a list of Elements that are different. Below is the XML, I was wondering if anyone can assist. In the case below, I want the list to contain the "file2.xml" element and the "file3.xml" element because they are both different or new than the first xml document. Thanks in advance! <?xml version="1.0" encoding="utf-8" ?> <versioninfo> <files> <file version="1.0">file1.xml</file> <file version="1.0">file2.xml</file> </files> </versioninfo> <?xml version="1.0" encoding="utf-8" ?> <versioninfo> <files> <file version="1.0">file1.xml</file> <file version="1.1">file2.xml</file> <file version="1.0">file3.xml</file> </files> </versioninfo>

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  • How should backbone.js handle a GET request that returns no results?

    - by Nyxynyx
    I have a number of text input elements that when its values are changed, will trigger a fetch on listingListView's collection listingCollection, which then updates listingListView with the new data via the function listingListView.refreshList as shown below. I am using PHP/Codeigniter to expose a RESTful API. Problem: Everything works fine if there are results retrieved from the fetch(). However, when the filters results in no result being returned, how should the server side and the client side handle it? Currently Chrome's javascript console displays a 404 error and in the Network tab, the XHR request is highlighted in red. All I want to do in the event of zero results returned, is to blank the listingListView and show a message like (No results returned) and not throw any errors in the javascript console. Thanks! PHP Code function listings_get() { // Get filters $price_min = $this->get('price_min'); $this->load->model('app_model'); $results = $this->app_model->get_listings($price_min); if($results) $this->response($results); else $this->response(NULL); } JS Code window.ListingListView = Backbone.View.extend({ tagName: 'table', initialize: function() { this.model.bind('reset', this.refreshList, this); this.model.bind('add', function(listing) { $(this.el).append(new ListingListItemView({ model: listing }).render().el); }, this); }, render: function() { _.each(this.model.models, function(listing) { $(this.el).append(new ListingListItemView({ model: listing }).render().el); }, this); return this; }, close: function() { $(this.el).unbind(); $(this.el).empty(); }, refreshList: function() { $(this.el).empty(); this.render(); } });

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  • VB.NET switching from ADO.NET to LINQ

    - by Cj Anderson
    I'm VERY new to Linq. I have an application I wrote that is in VB.NET 2.0. Works great, but I'd like to switch this application to Linq. I use ADO.NET to load XML into a datatable. The XML file has about 90,000 records in it. I then use the Datatable.Select to perform searches against that Datatable. The search control is a free form textbox. So if the user types in terms it searches instantly. Any further terms that are typed in continue to restrict the results. So you can type in Bob, or type in Bob Barker. Or type in Bob Barker Price is Right. The more criteria typed in the more narrowed your result. I bind the results to a gridview. Moving forward what all do I need to do? From a high level, I assume I need to: 1) Go to Project Properties -- Advanced Compiler Settings and change the Target framework to 3.5 from 2.0. 2) Add the reference to System.XML.Linq, Add the Imports statement to the classes. So I'm not sure what the best approach is going forward after that. I assume I use XDocument.Load, then my search subroutine runs against the XDocument. Do I just do the standard Linq query for this sort of repeated search? Like so: var people = from phonebook in doc.Root.Elements("phonebook") where phonebook.Element("userid") = "whatever" select phonebook; Any tips on how to best implement?

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  • Zipping with padding in Haskell

    - by Travis Brown
    A couple of times I've found myself wanting a zip in Haskell that adds padding to the shorter list instead of truncating the longer one. This is easy enough to write. (Monoid works for me here, but you could also just pass in the elements that you want to use for padding.) zipPad :: (Monoid a, Monoid b) => [a] -> [b] -> [(a, b)] zipPad xs [] = zip xs (repeat mempty) zipPad [] ys = zip (repeat mempty) ys zipPad (x:xs) (y:ys) = (x, y) : zipPad xs ys This approach gets ugly when trying to define zipPad3. I typed up the following and then realized that of course it doesn't work: zipPad3 :: (Monoid a, Monoid b, Monoid c) => [a] -> [b] -> [c] -> [(a, b, c)] zipPad3 xs [] [] = zip3 xs (repeat mempty) (repeat mempty) zipPad3 [] ys [] = zip3 (repeat mempty) ys (repeat mempty) zipPad3 [] [] zs = zip3 (repeat mempty) (repeat mempty) zs zipPad3 xs ys [] = zip3 xs ys (repeat mempty) zipPad3 xs [] zs = zip3 xs (repeat mempty) zs zipPad3 [] ys zs = zip3 (repeat mempty) ys zs zipPad3 (x:xs) (y:ys) (z:zs) = (x, y, z) : zipPad3 xs ys zs At this point I cheated and just used length to pick the longest list and pad the others. Am I overlooking a more elegant way to do this, or is something like zipPad3 already defined somewhere?

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  • Load an html table from a mysql database when an onChange event is triggered from a select tag

    - by Crew Peace
    So, here's the deal. I have an html table that I want to populate. Specificaly the first row is the one that is filled with elements from a mysql database. To be exact, the table is a questionnaire about mobile phones. The first row is the header where the cellphone names are loaded from the database. There is also a select tag that has company names as options in it. I need to trigger an onChange event on the select tag to reload the page and refill the first row with the new names of mobiles from the company that is currently selected in the dropdown list. This is what my select almost looks like: <select name="select" class="companies" onChange="reloadPageWithNewElements()"> <?php $sql = "SELECT cname FROM companies;"; $rs = mysql_query($sql); while($row = mysql_fetch_array($rs)) { echo "<option value=\"".$row['cname']."\">".$row['cname']."</option>\n "; } ?> </select> So... is there a way to refresh this page with onChange and pass the selected value to the same page again and assign it in a new php variable so i can do the query i need to fill my table? <?php //$mobileCompanies = $_GET["selectedValue"]; $sql = "SELECT mname FROM ".$mobileCompanies.";"; $rs = mysql_query($sql); while ($row = mysql_fetch_array($rs)) { echo "<td><div class=\"q1\">".$row['mname']."</div></td>"; } ?> something like this. (The reloadPageWithNewElements() and selectedValue are just an idea for now)

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  • FluentNHibernate, getting 1 column from another table

    - by puffpio
    We're using FluentNHibernate and we have run into a problem where our object model requires data from two tables like so: public class MyModel { public virtual int Id { get; set; } public virtual string Name { get; set; } public virtual int FooId { get; set; } public virtual string FooName { get; set; } } Where there is a MyModel table that has Id, Name, and FooId as a foreign key into the Foo table. The Foo tables contains Id and FooName. This problem is very similar to another post here: http://stackoverflow.com/questions/1896645/nhibernate-join-tables-and-get-single-column-from-other-table but I am trying to figure out how to do it with FluentNHibernate. I can make the Id, Name, and FooId very easily..but mapping FooName I am having trouble with. This is my class map: public class MyModelClassMap : ClassMap<MyModel> { public MyModelClassMap() { this.Id(a => a.Id).Column("AccountId").GeneratedBy.Identity(); this.Map(a => a.Name); this.Map(a => a.FooId); // my attempt to map FooName but it doesn't work this.Join("Foo", join => join.KeyColumn("FooId").Map(a => a.FooName)); } } with that mapping I get this error: The element 'class' in namespace 'urn:nhibernate-mapping-2.2' has invalid child element 'join' in namespace 'urn:nhibernate-mapping-2.2'. List of possible elements expected: 'joined-subclass, loader, sql-insert, sql-update, sql-delete, filter, resultset, query, sql-query' in namespace 'urn:nhibernate-mapping-2.2'. any ideas?

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  • Python script to calculate aded combinations from a dictionary

    - by dayde
    I am trying to write a script that will take a dictionary of items, each containing properties of values from 0 - 10, and add the various elements to select which combination of items achieve the desired totals. I also need the script to do this, using only items that have the same "slot" in common. For example: item_list = { 'item_1': {'slot': 'top', 'prop_a': 2, 'prop_b': 0, 'prop_c': 2, 'prop_d': 1 }, 'item_2': {'slot': 'top', 'prop_a': 5, 'prop_b': 0, 'prop_c': 1, 'prop_d':-1 }, 'item_3': {'slot': 'top', 'prop_a': 2, 'prop_b': 5, 'prop_c': 2, 'prop_d':-2 }, 'item_4': {'slot': 'mid', 'prop_a': 5, 'prop_b': 5, 'prop_c':-5, 'prop_d': 0 }, 'item_5': {'slot': 'mid', 'prop_a':10, 'prop_b': 0, 'prop_c':-5, 'prop_d': 0 }, 'item_6': {'slot': 'mid', 'prop_a':-5, 'prop_b': 2, 'prop_c': 3, 'prop_d': 5 }, 'item_7': {'slot': 'bot', 'prop_a': 1, 'prop_b': 3, 'prop_c':-4, 'prop_d': 4 }, 'item_8': {'slot': 'bot', 'prop_a': 2, 'prop_b': 2, 'prop_c': 0, 'prop_d': 0 }, 'item_9': {'slot': 'bot', 'prop_a': 3, 'prop_b': 1, 'prop_c': 4, 'prop_d':-4 }, } The script would then need to select which combinations from the "item_list" dict that using 1 item per "slot" that would achieve a desired result when added. For example, if the desired result was: 'prop_a': 3, 'prop_b': 3, 'prop_c': 8, 'prop_d': 0, the script would select 'item_2', 'item_6', and 'item_9', along with any other combination that worked. 'item_2': {'slot': 'top', 'prop_a': 5, 'prop_b': 0, 'prop_c': 1, 'prop_d':-1 } 'item_6': {'slot': 'mid', 'prop_a':-5, 'prop_b': 2, 'prop_c': 3, 'prop_d': 5 } 'item_9': {'slot': 'bot', 'prop_a': 3, 'prop_b': 1, 'prop_c': 4, 'prop_d':-4 } 'total': 'prop_a': 3, 'prop_b': 3, 'prop_c': 8, 'prop_d': 0 Any ideas how to accomplish this? It does not need to be in python, or even a thorough script, but just an explanation on how to do this in theory would be enough for me. I have tried working out looping through every combination, but that seems to very quickly get our of hand and unmanageable. The actual script will need to do this for about 1,000 items using 20 different "slots", each with 8 properties. Thanks for the help!

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  • passing groups of properties from 1 class to another

    - by insanepaul
    I have a group of 13 properties in a class. I created a struct for these properties and passed it to another class. I need to add another 10 groups of these 13 properties. So thats 130 properties in total. What do I do? I could add all 130 properties to the struct. Will this affect performance and readability I could create a list of structs but don't know how to access an item eg. to add to the list: listRowItems.Add(new RowItems(){a=1, b=1, c=1, d=1...}); listRowItems.Add(new RowItems(){a=2, b=2, c=2, d=2...}); How do I access the second group item b? is it Could I use just a dictionary with 130 items Should I use a list of dictionaries (again I don't know how to access a particular item) Should I pass in a class of 130 properties Just for your interest the properties are css parameters used for a composite control. The control displays 13 elements in each row and there are 10 rows and each row is customisable.

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  • Delphi : Handling the fact that Strings are not Objects

    - by awmross
    I am trying to write a function that takes any TList and returns a String representation of all the elements of the TList. I tried a function like so function ListToString(list:TList<TObject>):String; This works fine, except you can't pass a TList to it. E2010 Incompatible types: 'TList<System.TObject>' and 'TList<System.string>' In Delphi, a String is not an Object. To solve this, I've written a second function: function StringListToString(list:TList<string>):String; Is this the only solution? Are there other ways to treat a String as more 'object-like'? In a similar vein, I also wanted to write an 'equals' function to compare two TLists. Again I run into the same problem function AreListsEqual(list1:TList<TObject>; list2:TList<TObject>):boolean; Is there any way to write this function (perhaps using generics?) so it can also handle a TList? Are there any other tricks or 'best practises' I should know about when trying to create code that handles both Strings and Objects? Or do I just create two versions of every function? Can generics help? I am from a Java background but now work in Delphi. It seems they are lately adding a lot of things to Delphi from the Java world (or perhaps the C# world, which copied them from Java). Like adding equals() and hashcode() to TObject, and creating a generic Collections framework etc. I'm wondering if these additions are very practical if you can't use Strings with them.

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  • Design PDF template and populate data at runtime using java,xml etc..

    - by Samant
    well i have been looking for a java based PDF solutions...we dont have a clean way i guess-still.. all solutions are primitive and kind of workarounds... No easy solution for this requirement - 1. Designing a PDF template using a IDE (eg. Livecycle designer ..which is not free) 2. Then at runtime using java, populate data into this PDF template...either using xml or other datasources... such a simple requirement and NONE has a good "open-source and free" solution yet ! Is anyone aware of any ? I have been searching for since 3-4 years now..for a clean way out... Eclipse BIRT comes close.. but does not handle Barcode elements ..OOB. Jasper - ireport is also good but that tool does not have a table concept and is kind of annoying ! Also barcode support is not good. XSL-FO has not free IDE for design . Looking for a better answer .. got one ?

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  • JavaScript snippet to read and output XML file on page load?

    - by Banderdash
    Hey guys, hoping I might get some help. Have XML file here of a list of books each with unique id and numeral value for whether they are checked out or not. I need a JavaScript snippet that requests the XML file after the page loads and displays the content of the XML file. XML file looks like this: <?xml version="1.0" encoding="UTF-8" ?> <response> <library name="My Library"> <book id="1" checked-out="1"> <authors> <author>John Resig</author> </authors> <title>Pro JavaScript Techniques (Pro)</title> <isbn-10>1590597273</isbn-10> </book> <book id="2" checked-out="0"> <authors> <author>Erich Gamma</author> <author>Richard Helm</author> <author>Ralph Johnson</author> <author>John M. Vlissides</author> </authors> <title>Design Patterns: Elements of Reusable Object-Oriented Software</title> <isbn-10>0201633612</isbn-10> </book> ... </library> </response> Would LOVE any and all help!

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  • split all text inside dom element into <span>

    - by gruber
    I would like to split all elements inside html DOM node into spans with ids, for example: lets say I have element: <div> <h1>Header</h1> <h2>header2</h2> <p class="test">this is test p</p> </div> and the result should be: <div> <h1><span id="1">Header</span></h1> <h2><span id="2">header2</span></h2> <p class="test"><span id="3">this</span><span id="4">is</span><span id="5">test</span> <span id="6">p</span></p> </div> thanks for any help it shoul also work if there are nested images for example: <div> <h1>Header</h1> <h2>header2</h2> <p class="test"><img alt="test alt" />this is test p</p> </div> and the result: <div> <h1><span id="1">Header</span></h1> <h2><span id="2">header2</span></h2> <p class="test"><img alt="test alt" /><span id="3">this</span><span id="4">is</span><span id="5">test</span> <span id="6">p</span></p> </div>

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  • Fastest way to convert a list of doubles to a unique list of integers?

    - by javanix
    I am dealing with a MySQL table here that is keyed in a somewhat unfortunate way. Instead of using an auto increment table as a key, it uses a column of decimals to preserve order (presumably so its not too difficult to insert new rows while preserving a primary key and order). Before I go through and redo this table to something more sane, I need to figure out how to rekey it without breaking everything. What I would like to do is something that takes a list of doubles (the current keys) and outputs a list of integers (which can be cast down to doubles for rekeying). For example, input {1.00, 2.00, 2.50, 2.60, 3.00} would give output {1, 2, 3, 4, 5). Since this is a database, I also need to be able to update the rows nicely: UPDATE table SET `key`='3.00' WHERE `key`='2.50'; Can anyone think of a speedy algorithm to do this? My current thought is to read all of the doubles into a vector, take the size of the vector, and output a new vector with values from 1 => doubleVector.size. This seems pretty slow, since you wouldn't want to read every value into the vector if, for instance, only the last n/100 elements needed to be modified. I think there is probably something I can do in place, since only values after the first non-integer double need to be modified, but I can't for the life of me figure anything out that would let me update in place as well. For instance, setting 2.60 to 3.00 the first time you see 2.50 in the original key list would result in an error, since the key value 3.00 is already used for the table.

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  • Commercial Website architecture question

    - by Maxime ARNSTAMM
    Hello everyone, I have to write an architecture case study but there are some things that i don't know, so i'd like some pointers on the following : The website must handle 5k simultaneous users. The backend is composed by a commercial software, some webservices, some message queues, and a database. I want to recommend to use Spring for the backend, to deal with the different elements, and to expose some Rest services. I also want to recommend wicket for the front (not the point here). What i don't know is : must i install the front and the back on the same tomcat server or two different ? and i am tempted to put two servers for the front, with a load balancer (no need for session replication in this case). But if i have two front servers, must i have two back servers ? i don't want to create some kind of bottleneck. Based on what i read on this blog a really huge charge is handle by one tomcat only for the first website mentionned. But i cannot find any info on this, so i can't tell if it seems plausible. If you can enlight me, so i can go on in my case study, that would be really helpful. Thanks :)

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  • Javascript Rich Display WYSIWYG Component/Methodology

    - by Laramie
    quick back story-- I am working on ASP.Net based template editor that lets authors create text templates using Javascript inserted placeholder tags that will be filled in with dynamic text when the templates are used to display the final results. For example the author might create a template like The word [%12#add] was generated dynamically. The application would eventually replace the tag with a dynamic word down the road (though it's not specifically relevant to this post) The word foo was generated dynmamically. Depending on the circumstances, the template may be created in a text input, textarea or a modified version of the Ajax Control Toolkit HTML Editor. There might be 40 or more of these editable elements on the page, so using lots of stripped down or modified HTML editors would probably bog the page down too much. The problem is that the tags such as [%12#add] are displayed inline with the user text and the result is confusing and aesthetically gross. The goal is parse the contens of the source element and when a tags such as [%12#add] are encountered, display something prettier and less cryptic to the user such as a stylable element or image wherever tags such as [%12#add] occur. The application still needs the template text with the tags on postback. So the user might see The word tag placeholder was generated dynamically. but the original template would still be the value of the text input box The word [%12#add] was generated dynamically. It seems HTML editors like the ACT version and FckEditor accomplish this by rendering their output in an IFrame, but rather than kill myself trying to roll a lighter specialized version myself, I thought I'd ask if anyone knows of an existing free component or approach that has already tackled this. With good reason, I don't think S.O. allows HTML formatting, but the bold "tag placeholder" above would ideally be something like tag placeholder.

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  • Ajax heavy JS apps using excessive amounts of memory over time.

    - by Shane Reustle
    I seem to have some pretty large memory leaks in an app that I am working on. The app itself is not very complex. Every 15 seconds, the page requests approx 40kb of JSON from the server, and draws a table on the page using it. It is cheaper to draw the table over because the data is usually always new. I am attaching a few events to the table, approx 5 per line, 30 lines in the table. I used jQuery's .html() method to put the new html into the container and overwrite the existing. I do this specifically so that jQuery's special cleanup functions go in and attempt to detach all events on the elements in the element that it is overwriting. I then also delete the large variables of html once they are sent to the DOM using delete my_var. I have checked for circular references and attached events that are never cleared a few times, but never REALLY dug into it. I was wondering if someone could give me a few pointers on how to optimize a very heavy app like this. I just picked up "High Performance Javascript" by Nicholas Zakas, but didn't have much time to get into it yet. To give an idea on how much memory this is using, after 4~ hours, it is using about 420,000k on chrome, and much more on Firefox or IE. Thanks!

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  • How to apply CSS theme to only a specific jQuery-UI element?

    - by Thierry-Dimitri Roy
    I have a web site already build with my own CSS theme. I'm using jQuery UI "tabs" widget but no CSS from jQuery-UI. Now, I'm trying to add the "Date Picker" widget in one of my page. It would be great if I could reuse jQuery-UI default theme which is just fine. The problem is that the date picker theme is also applied to my tabs CSS. For example the "ui-widget" css properties is applied to both date picker and tabs elements. I can't seem to find a way to apply the css properties to only the date picker. I can't see a "super selector" that only applies to the date picker DIV. What would be the best way to handle this? [EDIT] The datepicker widget is really the problem. I cannot apply CSS style specific to it. Here is the starting code of the DIV that get pops up: <div style="position: absolute; top: 300.4px; left: 149px; display: block;" id="ui-datepicker-div" class="ui-datepicker ui-widget ui-widget-content ui-helper-clearfix ui-corner-all ui-helper-hidden-accessible"><div class="ui-datepicker-header ui-widget-header ui-helper-clearfix ui-corner-all"> As such, I cannot add a super selector. What would be great would be that the date picker widget supports CSS scope. But it does not. I'm stuck manually editing the jQuery CSS file. The Date Picker is currently being refactored. Hopefully the new code will address this issue.

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  • Passing IDisposable objects through constructor chains

    - by Matt Enright
    I've got a small hierarchy of objects that in general gets constructed from data in a Stream, but for some particular subclasses, can be synthesized from a simpler argument list. In chaining the constructors from the subclasses, I'm running into an issue with ensuring the disposal of the synthesized stream that the base class constructor needs. Its not escaped me that the use of IDisposable objects this way is possibly just dirty pool (plz advise?) for reasons I've not considered, but, this issue aside, it seems fairly straightforward (and good encapsulation). Codes: abstract class Node { protected Node (Stream raw) { // calculate/generate some base class properties } } class FilesystemNode : Node { public FilesystemNode (FileStream fs) : base (fs) { // all good here; disposing of fs not our responsibility } } class CompositeNode : Node { public CompositeNode (IEnumerable some_stuff) : base (GenerateRaw (some_stuff)) { // rogue stream from GenerateRaw now loose in the wild! } static Stream GenerateRaw (IEnumerable some_stuff) { var content = new MemoryStream (); // molest elements of some_stuff into proper format, write to stream content.Seek (0, SeekOrigin.Begin); return content; } } I realize that not disposing of a MemoryStream is not exactly a world-stopping case of bad CLR citizenship, but it still gives me the heebie-jeebies (not to mention that I may not always be using a MemoryStream for other subtypes). It's not in scope, so I can't explicitly Dispose () it later in the constructor, and adding a using statement in GenerateRaw () is self-defeating since I need the stream returned. Is there a better way to do this? Preemptive strikes: yes, the properties calculated in the Node constructor should be part of the base class, and should not be calculated by (or accessible in) the subclasses I won't require that a stream be passed into CompositeNode (its format should be irrelevant to the caller) The previous iteration had the value calculation in the base class as a separate protected method, which I then just called at the end of each subtype constructor, moved the body of GenerateRaw () into a using statement in the body of the CompositeNode constructor. But the repetition of requiring that call for each constructor and not being able to guarantee that it be run for every subtype ever (a Node is not a Node, semantically, without these properties initialized) gave me heebie-jeebies far worse than the (potential) resource leak here does.

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  • Domain model: should things like Logging, Audit, Persistence be in it

    - by hom.tanks
    I'm having a hard time convincing our architect that a Domain model should only have the essential elements of the business domain on it. Things like the fact that a class is persistable, that it needs logging and auditing and that it has a RESTful URI should not drive the domain model. They can be added later on, by using interfaces. Ours is a healthcare information management system. At the very coarse level, its a system where users login and access their healthcare information. They can share this information with others and be custodian for others' information (think Roles). But because of a few sound bytes that caught on early like "Everything should be a REST resource" the model now has a top level class called Resource that every other class extends from. I'm trying to make him see that the domain model should have well defined concepts like User Account, HealthDocument, UserRole etc which are distinct entities of the business , with specific associations between them. Clubbing everything under Resource class lets our model be inflexible besides being potentially incorrect. But he wants me to show him why its a bad idea to do it his way. I don't know how to articulate that properly but all my OO instincts tell me that its just not right. Any thoughts?

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  • WebService Stubs WSDL Axis2

    - by tt0686
    Good afternoon in my timezone. I have a wsdl file with the following snippet of code: <schema targetNamespace="http://util.cgd.pt" xmlns="http://www.w3.org/2001/XMLSchema"> <import namespace="http://schemas.xmlsoap.org/soap/encoding/" /> <complexType name="Attribute"> <sequence> <element name="fieldType" nillable="true" type="xsd:string" /> <element name="dataType" nillable="true" type="xsd:string" /> <element name="name" nillable="true" type="xsd:string" /> <element name="value" nillable="true" type="xsd:string" /> </sequence> </complexType> <complexType name="ArrayOffAttribute"> <complexContent> <restriction base="soapenc:Array"> <attribute ref="soapenc:arrayType" wsdl:arrayType="tns3:Attribute[]" /> </restriction> </complexContent> </complexType> When i use jax-rpc or Axis1 to generate the stubs the type Attribute is generated, but when i use Axis2 the type Attribute is not generated and a new type is created ArrayOffAttribute, this new type extends the axis2.databinding.types.soapencoding.Array and permits to add elements through the array.addObject(object), my question is, i am migrating one Java EE application from webservices using jax-rpc to start using Axis2, and the methods are using the Attribute type to fullfill attributes fields, now in Axis2 and do not have attribute type , what should i use in the ArrayOffAttribute.addObject(?) ? Could be something wrong with Axis2 ? i am stop here :( Thanks in advance Best regards

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  • how to implement a sparse_vector class

    - by Neil G
    I am implementing a templated sparse_vector class. It's like a vector, but it only stores elements that are different from their default constructed value. So, sparse_vector would store the index-value pairs for all indices whose value is not T(). I am basing my implementation on existing sparse vectors in numeric libraries-- though mine will handle non-numeric types T as well. I looked at boost::numeric::ublas::coordinate_vector and eigen::SparseVector. Both store: size_t* indices_; // a dynamic array T* values_; // a dynamic array int size_; int capacity_; Why don't they simply use vector<pair<size_t, T>> data_; My main question is what are the pros and cons of both systems, and which is ultimately better? The vector of pairs manages size_ and capacity_ for you, and simplifies the accompanying iterator classes; it also has one memory block instead of two, so it incurs half the reallocations, and might have better locality of reference. The other solution might search more quickly since the cache lines fill up with only index data during a search. There might also be some alignment advantages if T is an 8-byte type? It seems to me that vector of pairs is the better solution, yet both containers chose the other solution. Why?

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