Search Results

Search found 40622 results on 1625 pages for 'list of stuff'.

Page 707/1625 | < Previous Page | 703 704 705 706 707 708 709 710 711 712 713 714  | Next Page >

  • optimizing the jquery in django

    - by sankar
    I have done the following code which actually dynamically generate the values in the third list box using ajax and jquery concepts. Thoug it works, i need to optimize it. Below is the code i am working on now. <html> <head> <title>Comparison based on ID Number</title> <script src="http://code.jquery.com/jquery-latest.js"></script> </head> <body> {% if form.errors %} <p style="color: red;"> Please correct the error{{ form.errors|pluralize }} below. </p> {% endif %} <form action="/idnumber/" method="post" align= "center">{% csrf_token %} <p>Select different id numbers and the name of the <b> Measurement Group </b>to start the comparison</p> <table align = "center"> <tr> <th><label for="id_criteria_1">Id Number 1:</label></th> <th> {{ form.idnumber_1 }} </th> </tr> <tr> <th><label for="id_criteria_2">Id Number 2:</label></th> <th> {{ form.idnumber_2 }} </th> </tr> <tr> <th><label for="group_name_list">Group Name:</label></th> <th><select name="group_name_list" id="id_group_name_list"> <option>Select</option> </select> </th> </tr> <script> $('#id_idnumber_2').change( function get_group_names() { var value1 = $('#id_idnumber_1').attr('value'); var value2 = $(this).attr('value'); alert(value1); alert(value2); var request = $.ajax({ url: "/getGroupnamesforIDnumber/", type: "GET", data: {idnumber_1 : value1,idnumber_2 : value2}, dataType: "json", success: function(data) { alert(data); var myselect = document.getElementById("group_name_list"); document.getElementById("group_name_list").options.length = 1; var length_of_data = data.length; alert(length_of_data); try{ for(var i = 0;i < length_of_data; i++) { myselect.add(new Option(data[i].group_name, "i"), myselect.options[i]) //add new option to beginning of "sample" } } catch(e){ //in IE, try the below version instead of add() for(var i = 0;i < length_of_data; i++) { myselect.add(new Option(data[i].group_name, data[i].group_name)) //add new option to end of "sample" } } } }); }); </script> <tr align = "center"><th><input type="submit" value="Submit"></th></tr> </table> </form> </body> </html> everything works fine but there is a little problem in my code. (ie) my ajax function calls only when there is a change in the select list 2 (ie) 'id_number_2'. I want to make it call in such a way that which ever select box, the third list box should be updated automatically. Can anyone please help me on this with a possible logical solution

    Read the article

  • linux script, standard directory locations.

    - by Thingomy
    I am trying to write a bash script to do a task, I have done pretty well so far, and have it working to an extent, but I want to set it up so it's distributable to other people, and will be opening it up as open source, so I want to start doing things the "conventional" way. Unfortunately I'm not all that sure what the conventional way is. Ideally I want a link to an in depth online resource that discusses this and surrounding topics in depth, but I'm having difficulty finding keywords that will locate this on google. At the start of my script I set a bunch of global variables that store the names of the dirs that it will be accessing, this means that I can modify the dir's quickly, but this is programming shortcuts, not user shortcuts, I can't tell the users that they have to fiddle with this stuff. Also, I need for individual users' settings not to get wiped out on every upgrade. Questions: Name of settings folder: ~/.foo/ -- this is well and good, but how do I keep my working copy and my development copy separate? tweek the reference in the source of the dev version? If my program needs to maintain and update library of data (gps tracklog data in this case) where should this directory be? the user will need to access some of this data, but it's mostly for internal use. I personally work in cygwin, and I like to keep this data on separate drive, so the path is wierd, I suspect many users could find this. for a default however I'm thinking ~/gpsdata/ -- would this be normal, or should I hard code a system that ask the user at first run where to put it, and stores this in the settings folder? whatever happens I'm going ot have to store the directory reference in a file in the settings folder. The program needs a data "inbox" that is a folder that the user can dump files, then run the script to process these files. I was thinking ~/gpsdata/in/ ?? though there will always be an option to add a file or folder to the command line to use that as well (it processed files all locations listed, including the "inbox") Where should the script its self go? it's already smart enough that it can create all of it's ancillary/settings files (once I figure out the "correct" directory) if run with "./foo --setup" I could shove it in /usr/bin/ or /bin or ~/.foo/bin (and add that to the path) what's normal? I need to store login details for a web service that it will connect to (using curl -u if it matters) plan on including a setting whereby it asks for a username and password every execution, but it currently stores it plane text in a file in ~/.foo/ -- I know, this is not good. The webservice (osm.org) does support oauth, but I have no idea how to get curl to use it -- getting curl to speak to the service in the first place was a hack. Is there a simple way to do a really basic encryption on a file like this to deter idiots armed with notepad? Sorry for the list of questions, I believe they are closely related enough for a single post. This is all stuff that stabbing at, but would like clarification/confirmation over.

    Read the article

  • Designing different Factory classes (and what to use as argument to the factories!)

    - by devoured elysium
    Let's say we have the following piece of code: public class Event { } public class SportEvent1 : Event { } public class SportEvent2 : Event { } public class MedicalEvent1 : Event { } public class MedicalEvent2 : Event { } public interface IEventFactory { bool AcceptsInputString(string inputString); Event CreateEvent(string inputString); } public class EventFactory { private List<IEventFactory> factories = new List<IEventFactory>(); public void AddFactory(IEventFactory factory) { factories.Add(factory); } //I don't see a point in defining a RemoveFactory() so I won't. public Event CreateEvent(string inputString) { try { //iterate through all factories. If one and only one of them accepts //the string, generate the event. Otherwise, throw an exception. return factories.Single(factory => factory.AcceptsInputString(inputString)).CreateEvent(inputString); } catch (InvalidOperationException e) { throw new InvalidOperationException("No valid factory found to generate this kind of Event!", e); } } } public class SportEvent1Factory : IEventFactory { public bool AcceptsInputString(string inputString) { return inputString.StartsWith("SportEvent1"); } public Event CreateEvent(string inputString) { return new SportEvent1(); } } public class MedicalEvent1Factory : IEventFactory { public bool AcceptsInputString(string inputString) { return inputString.StartsWith("MedicalEvent1"); } public Event CreateEvent(string inputString) { return new MedicalEvent1(); } } And here is the code that runs it: static void Main(string[] args) { EventFactory medicalEventFactory = new EventFactory(); medicalEventFactory.AddFactory(new MedicalEvent1Factory()); medicalEventFactory.AddFactory(new MedicalEvent2Factory()); EventFactory sportsEventFactory = new EventFactory(); sportsEventFactory.AddFactory(new SportEvent1Factory()); sportsEventFactory.AddFactory(new SportEvent2Factory()); } I have a couple of questions: Instead of having to add factories here in the main method of my application, should I try to redesign my EventFactory class so it is an abstract factory? It'd be better if I had a way of not having to manually add EventFactories every time I want to use them. So I could just instantiate MedicalFactory and SportsFactory. Should I make a Factory of factories? Maybe that'd be over-engineering? As you have probably noticed, I am using a inputString string as argument to feed the factories. I have an application that lets the user create his own events but also to load/save them from text files. Later, I might want to add other kinds of files, XML, sql connections, whatever. The only way I can think of that would allow me to make this work is having an internal format (I choose a string, as it's easy to understand). How would you make this? I assume this is a recurrent situation, probably most of you know of any other more intelligent approach to this. I am then only looping in the EventFactory for all the factories in its list to check if any of them accepts the input string. If one does, then it asks it to generate the Event. If you find there is something wrong or awkward with the method I'm using to make this happen, I'd be happy to hear about different implementations. Thanks! PS: Although I don't show it in here, all the different kind of events have different properties, so I have to generate them with different arguments (SportEvent1 might have SportName and Duration properties, that have to be put in the inputString as argument).

    Read the article

  • Object validator - is this good design?

    - by neo2862
    I'm working on a project where the API methods I write have to return different "views" of domain objects, like this: namespace View.Product { public class SearchResult : View { public string Name { get; set; } public decimal Price { get; set; } } public class Profile : View { public string Name { get; set; } public decimal Price { get; set; } [UseValidationRuleset("FreeText")] public string Description { get; set; } [SuppressValidation] public string Comment { get; set; } } } These are also the arguments of setter methods in the API which have to be validated before storing them in the DB. I wrote an object validator that lets the user define validation rulesets in an XML file and checks if an object conforms to those rules: [Validatable] public class View { [SuppressValidation] public ValidationError[] ValidationErrors { get { return Validator.Validate(this); } } } public static class Validator { private static Dictionary<string, Ruleset> Rulesets; static Validator() { // read rulesets from xml } public static ValidationError[] Validate(object obj) { // check if obj is decorated with ValidatableAttribute // if not, return an empty array (successful validation) // iterate over the properties of obj // - if the property is decorated with SuppressValidationAttribute, // continue // - if it is decorated with UseValidationRulesetAttribute, // use the ruleset specified to call // Validate(object value, string rulesetName, string FieldName) // - otherwise, get the name of the property using reflection and // use that as the ruleset name } private static List<ValidationError> Validate(object obj, string fieldName, string rulesetName) { // check if the ruleset exists, if not, throw exception // call the ruleset's Validate method and return the results } } public class Ruleset { public Type Type { get; set; } public Rule[] Rules { get; set; } public List<ValidationError> Validate(object property, string propertyName) { // check if property is of type Type // if not, throw exception // iterate over the Rules and call their Validate methods // return a list of their return values } } public abstract class Rule { public Type Type { get; protected set; } public abstract ValidationError Validate(object value, string propertyName); } public class StringRegexRule : Rule { public string Regex { get; set; } public StringRegexRule() { Type = typeof(string); } public override ValidationError Validate(object value, string propertyName) { // see if Regex matches value and return // null or a ValidationError } } Phew... Thanks for reading all of this. I've already implemented it and it works nicely, and I'm planning to extend it to validate the contents of IEnumerable fields and other fields that are Validatable. What I'm particularly concerned about is that if no ruleset is specified, the validator tries to use the name of the property as the ruleset name. (If you don't want that behavior, you can use [SuppressValidation].) This makes the code much less cluttered (no need to use [UseValidationRuleset("something")] on every single property) but it somehow doesn't feel right. I can't decide if it's awful or awesome. What do you think? Any suggestions on the other parts of this design are welcome too. I'm not very experienced and I'm grateful for any help. Also, is "Validatable" a good name? To me, it sounds pretty weird but I'm not a native English speaker.

    Read the article

  • bind parent child listview asp.net

    - by Chris
    I'm trying to display two linq query results in a prent and child listview. I have the following code which gets the correct values to populate the listviews but when I nest the child listview inside the parent list view, I get an error saying "The name 'ListView2' does not exist in the current context". I presume I need to bind the two listviews in the code behind but my problem is I don't know how or the best way to do this. I have read a couple of posts on similar problems but my lack of knowledge on the subject doesn't make it clear to me. Please can somebody help me figure this out? It's the final piece of code I need to complete. Many thanks in advance. Here is my .aspx code: <asp:ListView ID="ListView1" runat="server"> <EmptyDataTemplate>No data was returned.</EmptyDataTemplate> <ItemSeparatorTemplate><br /></ItemSeparatorTemplate> <ItemTemplate> <li> <asp:Label ID="LabelID" runat="server" Text='<%# Eval("RecordID") %>'></asp:Label><br /> <asp:Label ID="LabelNumber" runat="server" Text='<%# Eval("CartID") %>'></asp:Label><br /> <asp:Label ID="LabelName" runat="server" Text='<%# Eval("Number") %>'></asp:Label><br /> <asp:Label ID="LabelDestination" runat="server" Text='<%# Eval("Destination") %>'></asp:Label><br /> <asp:Label ID="LabelPkgName" runat="server" Text='<%# Eval("PkgName") %>'></asp:Label> <li> <!-- LIST VIEW FOR FEATURES --> <asp:ListView ID="ListView2" runat="server"> <EmptyDataTemplate>No data was returned.</EmptyDataTemplate> <ItemSeparatorTemplate><br /></ItemSeparatorTemplate> <ItemTemplate> <li> <asp:Label ID="LabelFeatureName" runat="server" Text='<%# Eval("FeatureName") %>'></asp:Label><br /> <asp:Label ID="LabelFeatureSetUp" runat="server" Text='<%# Eval("FeatureSetUp") %>'></asp:Label><br /> <asp:Label ID="LabelFeatureMonthly" runat="server" Text='<%# Eval("FeatureMonthly") %>'></asp:Label><br /> </li> </ItemTemplate> <LayoutTemplate> <ul ID="itemPlaceholderContainer" runat="server" style=""> <li runat="server" id="itemPlaceholder" /> </ul> </LayoutTemplate> </asp:ListView> <!-- LIST VIEW FOR FEATURES [END] --> </li> </li> </ItemTemplate> <LayoutTemplate> <ul ID="itemPlaceholderContainer" runat="server" style=""> <li runat="server" id="itemPlaceholder" /> </ul> </LayoutTemplate> </asp:ListView> Here is my code behind: MyShoppingCart userShoppingCart = new MyShoppingCart(); string cartID = userShoppingCart.GetShoppingCartId(); using (ShoppingCartv2Entities db = new ShoppingCartv2Entities()) { var CartNumber = from c in db.NewViews where c.CartID == cartID select c; foreach (NewView item in CartNumber) { ListView1.DataSource = CartNumber; ListView1.DataBind(); } var CartFeature = from f in db.NewViews join o in db.NumberFeatureViews on f.RecordID equals o.RecordID where f.CartID == cartID select new { o.FeatureName, o.FeatureSetUp, o.FeatureMonthly }; foreach (var x in CartFeature) { ListView2.DataSource = CartFeature; ListView2.DataBind(); } }

    Read the article

  • method is not called from xhtml

    - by Amlan Karmakar
    Whenever I am clicking the h:commandButton,the method associated with the action is not called.action="${statusBean.update}" is not working, the update is not being called. 1) Here is my xhtml page <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:p="http://primefaces.org/ui"> <h:head></h:head> <h:body> <h:form > <p:dataList value="#{statusBean.statusList}" var="p"> <h:outputText value="#{p.statusId}-#{p.statusmsg}"/><br/> <p:inputText value="#{statusBean.comment.comment}"/> <h:commandButton value="comment" action="${statusBean.update}"></h:commandButton> </p:dataList> </h:form> </h:body> </html> 2)Here is my statusBean package com.bean; import java.util.List; import javax.faces.context.FacesContext; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; import javax.persistence.Query; import javax.servlet.http.HttpSession; import com.entity.Album; import com.entity.Comment; import com.entity.Status; import com.entity.User; public class StatusBean { Comment comment; Status status; private EntityManager em; public Comment getComment() { return comment; } public void setComment(Comment comment) { this.comment = comment; } public Status getStatus() { return status; } public void setStatus(Status status) { this.status = status; } public StatusBean(){ comment = new Comment(); status=new Status(); EntityManagerFactory emf=Persistence.createEntityManagerFactory("FreeBird"); em =emf.createEntityManager(); } public String save(){ FacesContext context = FacesContext.getCurrentInstance(); HttpSession session = (HttpSession) context.getExternalContext().getSession(true); User user = (User) session.getAttribute("userdet"); status.setEmail(user.getEmail()); System.out.println("status save called"); em.getTransaction().begin(); em.persist(status); em.getTransaction().commit(); return "success"; } public List<Status> getStatusList(){ FacesContext context = FacesContext.getCurrentInstance(); HttpSession session = (HttpSession) context.getExternalContext().getSession(true); User user=(User) session.getAttribute("userdet"); Query query = em.createQuery("SELECT s FROM Status s WHERE s.email='"+user.getEmail()+"'", Status.class); List<Status> results =query.getResultList(); return results; } public String update(){ System.out.println("Update Called..."); //comment.setStatusId(Integer.parseInt(statusId)); em.getTransaction().begin(); em.persist(comment); em.getTransaction().commit(); return "success"; } }

    Read the article

  • Custom Online Backup Solution Advice

    - by Martín Marconcini
    I have to implement a way so our customers can backup their SQL 2000/5/8 databasase online. The application they use is a C#/.NET35 Winforms application that connects to a SQL Server (can be 2000/2005/2008, sometimes express editions). The SQL Server is on the same LAN. Our application has a very specific UI and we must code each form following those guidelines. There’s lots of GDI+ to give it the look and feel we want. For that reason, using a 3rd party application is not a very good idea. We need to charge the customer on a monthly/annual basis for the service. Preferably, the customer doesn’t need to care about bandwidth and storage space. It must be transparent. Given the above reqs., my first thoughts are: Solution 1: Code some sort of FTP basic functionality with behind the scenes SQL Backup mechanism, then hire a Hosting service and compress-transfer the .BAK to the Hosting. Maintain a series of Folders (for each customer). They won’t see what’s happening. They will just see a list of their files and a big “Backup now” button that will perform the SQL backup, compress it and upload it (and update the file list) ;) Pros: Not very complicated to implement, simple to use, fairly simple to configure (could have a dedicated ftp user/pass) Cons: Finding a “ftp” only hosting plan is not probably going to be easy, they usually come with a bunch of stuff. FTP is not always the best protocol. more? Solution 2: Similar to 1, but instead of FTP, find a cloud computing service like Amazon S3, Mosso or similar. Pros: Cloud Storage is fast, reliable, etc. It’s kind of easy to implement (specially if there are APIs like AWS or Mosso). Cons: I have been unable to come up with a service optimized for resellers where I can give multiple sub-accounts (one for each customer). Billing is going to be a nightmare cuz these services bill per/GB and with One account it’s impossible to differentiate each customer. Solution 3: Similar to 2, but letting the user create their own account on Amazon S3 (for example). Pros: You forget about billing and such. Cons: A mess for the customer who has to open the Amazon (or whatever) account, will be charged for that and not from you. You can’t really charge the customer (since you’re just not doing anything). Solution 4: Use one of the many backup online solutions that use the tech in cloud storage. Pros: many of these include SQL Server backup, and a lot of features that we’d have to implement. Plus web access and stuff like that will come included. Cons: Still have the billing problem described in number 2. Little of these companies (if any) offers “reseller” accounts. You have to eventually use their software (some offer certain branding). Any better approach? Summary: You have a software (.NET Winapp). You want your users to be able to backup their SQL Server databases online (and be able to retrieve the backups if needed). You ideally would like to charge the customer for this service (i.e. XX € a year).

    Read the article

  • mySQL to .XSL help

    - by kielie
    hi guys, I have to create a script that takes a mySQL table, and exports it into .XSL format, and then saves that file into a specified folder on the web host. I got it working, but now I can't seem to get it to automatically save the file to the location without prompting the user. It needs to run every day at a specified time, so it can save the previous days leads into a .XSL file on the web host. Here is the code: <?php // DB TABLE Exporter // // How to use: // // Place this file in a safe place, edit the info just below here // browse to the file, enjoy! // CHANGE THIS STUFF FOR WHAT YOU NEED TO DO $dbhost = "-"; $dbuser = "-"; $dbpass = "-"; $dbname = "-"; $dbtable = "-"; // END CHANGING STUFF $cdate = date("Y-m-d"); // get current date // first thing that we are going to do is make some functions for writing out // and excel file. These functions do some hex writing and to be honest I got // them from some where else but hey it works so I am not going to question it // just reuse // This one makes the beginning of the xls file function xlsBOF() { echo pack("ssssss", 0x809, 0x8, 0x0, 0x10, 0x0, 0x0); return; } // This one makes the end of the xls file function xlsEOF() { echo pack("ss", 0x0A, 0x00); return; } // this will write text in the cell you specify function xlsWriteLabel($Row, $Col, $Value ) { $L = strlen($Value); echo pack("ssssss", 0x204, 8 + $L, $Row, $Col, 0x0, $L); echo $Value; return; } // make the connection an DB query $dbc = mysql_connect( $dbhost , $dbuser , $dbpass ) or die( mysql_error() ); mysql_select_db( $dbname ); $q = "SELECT * FROM ".$dbtable." WHERE date ='$cdate'"; $qr = mysql_query( $q ) or die( mysql_error() ); // Ok now we are going to send some headers so that this // thing that we are going make comes out of browser // as an xls file. // header("Pragma: public"); header("Expires: 0"); header("Cache-Control: must-revalidate, post-check=0, pre-check=0"); header("Content-Type: application/force-download"); header("Content-Type: application/octet-stream"); header("Content-Type: application/download"); //this line is important its makes the file name header("Content-Disposition: attachment;filename=export_".$dbtable.".xls "); header("Content-Transfer-Encoding: binary "); // start the file xlsBOF(); // these will be used for keeping things in order. $col = 0; $row = 0; // This tells us that we are on the first row $first = true; while( $qrow = mysql_fetch_assoc( $qr ) ) { // Ok we are on the first row // lets make some headers of sorts if( $first ) { foreach( $qrow as $k => $v ) { // take the key and make label // make it uppper case and replace _ with ' ' xlsWriteLabel( $row, $col, strtoupper( ereg_replace( "_" , " " , $k ) ) ); $col++; } // prepare for the first real data row $col = 0; $row++; $first = false; } // go through the data foreach( $qrow as $k => $v ) { // write it out xlsWriteLabel( $row, $col, $v ); $col++; } // reset col and goto next row $col = 0; $row++; } xlsEOF(); exit(); ?> I tried using, fwrite to accomplish this, but it didn't seem to go very well, I removed the header information too, but nothing worked. Here is the original code, as I found it, any help would be greatly appreciated. :-) Thanx in advance. :-)

    Read the article

  • Dual AJAX Requests at different times

    - by Nik
    Alright, I'm trying to make an AJAX Chat system that polls the chat database every 400ms. That part is working, the part of which isn't is the Active User List. When I try to combine the two requests, the first two requests are made, then the whole thing snowballs and the usually timed (12 second) Active User List request starts updating every 1ms and the first request NEVER happens again. Displayed is the entire AJAX code for both requests: var waittime=400;chatmsg=document.getElementById("chatmsg"); room = document.getElementById("roomid").value; chatmsg.focus() document.getElementById("chatwindow").innerHTML = "loading..."; document.getElementById("userwindow").innerHTML = "Loading User List..."; var xmlhttp = false; var xmlhttp2 = false; var xmlhttp3 = false; function ajax_read(url) { if(window.XMLHttpRequest){ xmlhttp=new XMLHttpRequest(); if(xmlhttp.overrideMimeType){ xmlhttp.overrideMimeType('text/xml'); } } else if(window.ActiveXObject){ try{ xmlhttp=new ActiveXObject("Msxml2.XMLHTTP"); } catch(e) { try{ xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } catch(e){ } } } if(!xmlhttp) { alert('Giving up :( Cannot create an XMLHTTP instance'); return false; } xmlhttp.onreadystatechange = function() { if (xmlhttp.readyState==4) { document.getElementById("chatwindow").innerHTML = xmlhttp.responseText; setTimeout("ajax_read('methods.php?method=r&room=" + room +"')", waittime); } } xmlhttp.open('GET',url,true); xmlhttp.send(null); } function user_read(url) { if(window.XMLHttpRequest){ xmlhttp3=new XMLHttpRequest(); if(xmlhttp3.overrideMimeType){ xmlhttp3.overrideMimeType('text/xml'); } } else if(window.ActiveXObject){ try{ xmlhttp3=new ActiveXObject("Msxml2.XMLHTTP"); } catch(e) { try{ xmlhttp3=new ActiveXObject("Microsoft.XMLHTTP"); } catch(e){ } } } if(!xmlhttp3) { alert('Giving up :( Cannot create an XMLHTTP instance'); return false; } xmlhttp3.onreadystatechange = function() { if (xmlhttp3.readyState==4) { document.getElementById("userwindow").innerHTML = xmlhttp3.responseText; setTimeout("ajax_read('methods.php?method=u&room=" + room +"')", 12000); } } xmlhttp3.open('GET',url,true); xmlhttp3.send(null); } function ajax_write(url){ if(window.XMLHttpRequest){ xmlhttp2=new XMLHttpRequest(); if(xmlhttp2.overrideMimeType){ xmlhttp2.overrideMimeType('text/xml'); } } else if(window.ActiveXObject){ try{ xmlhttp2=new ActiveXObject("Msxml2.XMLHTTP"); } catch(e) { try{ xmlhttp2=new ActiveXObject("Microsoft.XMLHTTP"); } catch(e){ } } } if(!xmlhttp2) { alert('Giving up :( Cannot create an XMLHTTP instance'); return false; } xmlhttp2.open('GET',url,true); xmlhttp2.send(null); } function submit_msg(){ nick = document.getElementById("chatnick").value; msg = document.getElementById("chatmsg").value; document.getElementById("chatmsg").value = ""; ajax_write("methods.php?method=w&m=" + msg + "&n=" + nick + "&room=" + room + ""); } function keyup(arg1) { if (arg1 == 13) submit_msg(); } var intUpdate = setTimeout("ajax_read('methods.php')", waittime); var intUpdate = setTimeout("user_read('methods.php')", waittime);

    Read the article

  • xts error - order.by requires an appropriate time-based object

    - by Samo
    I can not resolve why error in simple creation of xts object xts(rep(0, NROW(TICK.NYSE)), order.by = index(TICK.NYSE)) Error in xts(rep(0, NROW(TICK.NYSE)), order.by = index(TICK.NYSE)) : order.by requires an appropriate time-based object appeared while this was working perfectly 14 days ago when I last used the same code (since then the only difference is that TICK.NYSE grow in length since data was added since then). More details below: > Sys.getenv("TZ") [1] "EST" > tail(xts(rep(0, NROW(TICK.NYSE)), order.by = index(TICK.NYSE))) Error in xts(rep(0, NROW(TICK.NYSE)), order.by = index(TICK.NYSE)) : order.by requires an appropriate time-based object > class(index(TICK.NYSE["T09:30/T09:31"])) [1] "POSIXct" > tail(xts(rep(0, NROW(tail(TICK.NYSE))), order.by = index(tail(TICK.NYSE)))) Error in xts(rep(0, NROW(tail(TICK.NYSE))), order.by = index(tail(TICK.NYSE))) : order.by requires an appropriate time-based object > tail(TICK.NYSE) TICK-NYSE.Open TICK-NYSE.High TICK-NYSE.Low TICK-NYSE.Close 2012-03-15 14:54:00 -278 -89 -299 -89 2012-03-15 14:55:00 -89 427 -89 201 2012-03-15 14:56:00 201 318 30 234 2012-03-15 14:57:00 234 242 -222 -64 2012-03-15 14:58:00 -64 346 -82 346 2012-03-15 14:59:00 346 525 36 525 TICK-NYSE.Volume TICK-NYSE.WAP TICK-NYSE.hasGaps 2012-03-15 14:54:00 0 0 0 2012-03-15 14:55:00 0 0 0 2012-03-15 14:56:00 0 0 0 2012-03-15 14:57:00 0 0 0 2012-03-15 14:58:00 0 0 0 2012-03-15 14:59:00 0 0 0 TICK-NYSE.Count 2012-03-15 14:54:00 31 2012-03-15 14:55:00 31 2012-03-15 14:56:00 31 2012-03-15 14:57:00 31 2012-03-15 14:58:00 29 2012-03-15 14:59:00 30 > str(TICK.NYSE) An ‘xts’ object from 2011-01-18 09:30:00 to 2012-03-15 14:59:00 containing: Data: num [1:114090, 1:8] -5 -144 24 -148 -184 -77 20 121 111 -60 ... - attr(*, "dimnames")=List of 2 ..$ : NULL ..$ : chr [1:8] "TICK-NYSE.Open" "TICK-NYSE.High" "TICK-NYSE.Low" "TICK-NYSE.Close" ... Indexed by objects of class: [POSIXct,POSIXt] TZ: xts Attributes: List of 4 $ from : chr "20110119 23:59:59" $ to : chr "20110124 23:59:59" $ src : chr "IB" $ updated: POSIXct[1:1], format: "2012-01-19 02:34:52" > str(index(TICK.NYSE)) Class 'POSIXct' atomic [1:114090] 1.3e+09 1.3e+09 1.3e+09 1.3e+09 1.3e+09 ... ..- attr(*, "tzone")= chr "" ..- attr(*, "tclass")= chr [1:2] "POSIXct" "POSIXt" > Sys.getenv("TZ") [1] "EST" > tail(index(TICK.NYSE)) [1] "2012-03-15 14:54:00 EST" "2012-03-15 14:55:00 EST" [3] "2012-03-15 14:56:00 EST" "2012-03-15 14:57:00 EST" [5] "2012-03-15 14:58:00 EST" "2012-03-15 14:59:00 EST" > head(index(TICK.NYSE)) [1] "2011-01-18 09:30:00 EST" "2011-01-18 09:31:00 EST" [3] "2011-01-18 09:32:00 EST" "2011-01-18 09:33:00 EST" [5] "2011-01-18 09:34:00 EST" "2011-01-18 09:35:00 EST" > Sys.info() sysname "Linux" release "3.0.0-16-generic" version "#28-Ubuntu SMP Fri Jan 27 17:44:39 UTC 2012" > sessionInfo() R version 2.14.1 (2011-12-22) Platform: x86_64-pc-linux-gnu (64-bit) locale: [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C [3] LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8 [5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 [7] LC_PAPER=en_US.UTF-8 LC_NAME=en_US.UTF-8 [9] LC_ADDRESS=en_US.UTF-8 LC_TELEPHONE=en_US.UTF-8 [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=en_US.UTF-8 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] lattice_0.20-0 multicore_0.1-7 [3] doSNOW_1.0.5 snow_0.3-8 [5] doRedis_1.0.4 rredis_1.6.3 [7] foreach_1.3.2 codetools_0.2-8 [9] iterators_1.0.5 PerformanceAnalytics_1.0.3.3 [11] quantstrat_0.6.1 blotter_0.8.4 [13] twsInstrument_1.3-3 FinancialInstrument_0.10.6 [15] IBrokers_0.9-6 quantmod_0.3-18 [17] TTR_0.21-0 xts_0.8-4 [19] Defaults_1.1-1 strucchange_1.4-6 [21] sandwich_2.2-8 zoo_1.7-7 [23] rj_1.0.2-5 loaded via a namespace (and not attached): [1] grid_2.14.1 tools_2.14.1 > dput(tail(TICK.NYSE)) structure(c(-385, -213, -42, -334, -233, -111, -121, 20, -14, -125, -73, 265, -583, -269, -426, -520, -443, -440, -213, -42, -334, -233, -111, 119, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 31, 31, 30, 30, 31, 31), class = c("xts", "zoo" ), .indexCLASS = c("POSIXct", "POSIXt"), .indexTZ = "", from = "20110119 23:59:59", to = "20110124 23:59:59", src = "IB", updated = structure(1326958492.96405, class = c("POSIXct", "POSIXt")), index = structure(c(1331927640, 1331927700, 1331927760, 1331927820, 1331927880, 1331927940), tzone = "", tclass = c("POSIXct", "POSIXt")), .Dim = c(6L, 8L), .Dimnames = list(NULL, c("TICK-NYSE.Open", "TICK-NYSE.High", "TICK-NYSE.Low", "TICK-NYSE.Close", "TICK-NYSE.Volume", "TICK-NYSE.WAP", "TICK-NYSE.hasGaps", "TICK-NYSE.Count")))

    Read the article

  • How do I get around this lambda expression outer variable issue?

    - by panamack
    I'm playing with PropertyDescriptor and ICustomTypeDescriptor (still) trying to bind a WPF DataGrid to an object, for which the data is stored in a Dictionary. Since if you pass WPF DataGrid a list of Dictionary objects it will auto generate columns based on the public properties of a dictionary (Comparer, Count, Keys and Values) my Person subclasses Dictionary and implements ICustomTypeDescriptor. ICustomTypeDescriptor defines a GetProperties method which returns a PropertyDescriptorCollection. PropertyDescriptor is abstract so you have to subclass it, I figured I'd have a constructor that took Func and an Action parameters that delegate the getting and setting of the values in the dictionary. I then create a PersonPropertyDescriptor for each Key in the dictionary like this: foreach (string s in this.Keys) { var descriptor = new PersonPropertyDescriptor( s, new Func<object>(() => { return this[s]; }), new Action<object>(o => { this[s] = o; })); propList.Add(descriptor); } The problem is that each property get's its own Func and Action but they all share the outer variable s so although the DataGrid autogenerates columns for "ID","FirstName","LastName", "Age", "Gender" they all get and set against "Gender" which is the final resting value of s in the foreach loop. How can I ensure that each delegate uses the desired dictionary Key, i.e. the value of s at the time the Func/Action is instantiated? Much obliged. Here's the rest of my idea, I'm just experimenting here these are not 'real' classes... // DataGrid binds to a People instance public class People : List<Person> { public People() { this.Add(new Person()); } } public class Person : Dictionary<string, object>, ICustomTypeDescriptor { private static PropertyDescriptorCollection descriptors; public Person() { this["ID"] = "201203"; this["FirstName"] = "Bud"; this["LastName"] = "Tree"; this["Age"] = 99; this["Gender"] = "M"; } //... other ICustomTypeDescriptor members... public PropertyDescriptorCollection GetProperties() { if (descriptors == null) { var propList = new List<PropertyDescriptor>(); foreach (string s in this.Keys) { var descriptor = new PersonPropertyDescriptor( s, new Func<object>(() => { return this[s]; }), new Action<object>(o => { this[s] = o; })); propList.Add(descriptor); } descriptors = new PropertyDescriptorCollection(propList.ToArray()); } return descriptors; } //... other other ICustomTypeDescriptor members... } public class PersonPropertyDescriptor : PropertyDescriptor { private Func<object> getFunc; private Action<object> setAction; public PersonPropertyDescriptor(string name, Func<object> getFunc, Action<object> setAction) : base(name, null) { this.getFunc = getFunc; this.setAction = setAction; } // other ... PropertyDescriptor members... public override object GetValue(object component) { return getFunc(); } public override void SetValue(object component, object value) { setAction(value); } }

    Read the article

  • Problem with ArrayList

    - by Houssem
    Hello, I'm reading an xml file from resources, that file contains a list of travel agencies location and adresses and i'm trying to put this list after parsing in an arraylist to use it with maps. So each time I use agencies.add(agency) it adds it to the array but also changes all previous items with the new value. Here's my code if someone can help or explain : public class Main extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); TextView myXmlContent = (TextView)findViewById(R.id.my_xml); String stringXmlContent; try { stringXmlContent = getEventsFromAnXML(this); myXmlContent.setText(stringXmlContent); } catch (XmlPullParserException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } boolean na=false; List<Agency> agencies = new ArrayList(); Agency agency=new Agency(); int i=0; private String getEventsFromAnXML(Activity activity) throws XmlPullParserException, IOException { StringBuffer stringBuffer = new StringBuffer(); Resources res = activity.getResources(); XmlResourceParser xpp = res.getXml(R.xml.hotels); xpp.next(); int eventType = xpp.getEventType(); while (eventType != XmlPullParser.END_DOCUMENT) { if(eventType == XmlPullParser.START_DOCUMENT) { stringBuffer.append("--- Start XML ---"); } else if(eventType == XmlPullParser.START_TAG) { if (xpp.getName().equals("DataBase")){ agency.ResetTsp(); String name=xpp.getAttributeValue(null, "name"); agency.setTspTitle(name); na=true; stringBuffer.append("\nAgence : "+ name); } if (xpp.getName().equals("Title")){ xpp.next(); agency.setTitle(xpp.getText()); stringBuffer.append("\nFiliale: "+xpp.getText()); xpp.nextTag(); } if (xpp.getName().equals("Address")){ xpp.next(); agency.setAddress(xpp.getText()); stringBuffer.append("\nAdresse: "+xpp.getText()); xpp.nextTag(); } if (xpp.getName().equals("Phone") && na==true){ xpp.next(); agency.setTspPhone(xpp.getText()); stringBuffer.append("\nPhone: "+xpp.getText()); xpp.nextTag(); }else{ if (xpp.getName().equals("Phone") && na==false){ xpp.next(); agency.setPhone(xpp.getText()); stringBuffer.append("\nPhone: "+xpp.getText()); xpp.nextTag(); } } if (xpp.getName().equals("Fax")){ xpp.next(); agency.setFax(xpp.getText()); stringBuffer.append("\nFax: "+xpp.getText()); xpp.nextTag(); } if (xpp.getName().equals("e-Mail")){ xpp.next(); agency.setMail(xpp.getText()); stringBuffer.append("\ne-Mail: "+xpp.getText()); xpp.nextTag(); } if (xpp.getName().equals("Latitude")){ xpp.next(); agency.setLatitude(Double.parseDouble(xpp.getText())); stringBuffer.append("\nLatitude: "+xpp.getText()); xpp.nextTag(); } if (xpp.getName().equals("Longitude")){ xpp.next(); agency.setLongitude(Double.parseDouble(xpp.getText())); stringBuffer.append("\nLongitude: "+xpp.getText()); } } else if(eventType == XmlPullParser.END_TAG) { if (xpp.getName().equals("DataBase") || xpp.getName().equals("Agency")){ agencies.add(i,agency); i=i+1; Agency agency = new Agency(); } } eventType = xpp.next(); } stringBuffer.append("\n--- End XML ---"); return stringBuffer.toString(); } } thank you

    Read the article

  • Having different database sorting order (default_scope) for two different views

    - by Juniper747
    In my model (pins.rb), I have two sorting orders: default_scope order: 'pins.featured DESC' #for adding featured posts to the top of a list default_scope order: 'pins.created_at DESC' #for adding the remaining posts beneath the featured posts This sorting order (above) is how I want my 'pins view' (index.html.erb) to look. Which is just a list of ALL user posts. In my 'users view' (show.html.erb) I am using the same model (pins.rb) to list only current_user pins. HOWEVER, I want to sorting order to ignore the "featured" default scope and only use the second scope: default_scope order: 'pins.created_at DESC' How can I accomplish this? I tried doing something like this: default_scope order: 'pins.featured DESC', only: :index default_scope order: 'pins.created_at DESC' But that didn't fly... UPDATE I updated my model to define a scope: scope :featy, order: 'pins.featured DESC' default_scope order: 'pins.created_at DESC' And updated my pins view to: <%= render @pins.featy %> However, now when I open my pins view, I get the error: undefined method `featy' for #<Array:0x00000100ddbc78> UPDATE 2 User.rb class User < ActiveRecord::Base attr_accessible :name, :email, :username, :password, :password_confirmation, :avatar, :password_reset_token, :password_reset_sent_at has_secure_password has_many :pins, dependent: :destroy #destroys user posts when user is destroyed # has_many :featured_pins, order: 'featured DESC', class_name: "Pin", source: :pin has_attached_file :avatar, :styles => { :medium => "300x300#", :thumb => "120x120#" } before_save { |user| user.email = user.email.downcase } before_save { |user| user.username = user.username.downcase } before_save :create_remember_token before_save :capitalize_name validates :name, presence: true, length: { maximum: 50 } VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i VALID_USERNAME_REGEX = /^[A-Za-z0-9]+(?:[_][A-Za-z0-9]+)*$/ validates :email, presence: true, format: { with: VALID_EMAIL_REGEX }, uniqueness: { case_sensitive: false } validates :username, presence: true, format: { with: VALID_USERNAME_REGEX }, uniqueness: { case_sensitive: false } validates :password, length: { minimum: 6 }, on: :create #on create, because was causing erros on pw_reset Pin.rb class Pin < ActiveRecord::Base attr_accessible :content, :title, :privacy, :date, :dark, :bright, :fragmented, :hashtag, :emotion, :user_id, :imagesource, :imageowner, :featured belongs_to :user before_save :capitalize_title before_validation :generate_slug validates :content, presence: true, length: { maximum: 8000 } validates :title, presence: true, length: { maximum: 24 } validates :imagesource, presence: { message: "Please search and choose an image" }, length: { maximum: 255 } validates_inclusion_of :privacy, :in => [true, false] validates :slug, uniqueness: true, presence: true, exclusion: {in: %w[signup signin signout home info privacy]} # for sorting featured and newest posts first default_scope order: 'pins.created_at DESC' scope :featured_order, order: 'pins.featured DESC' def to_param slug # or "#{id}-#{name}".parameterize end def generate_slug # makes the url slug address bar freindly self.slug ||= loop do random_token = Digest::MD5.hexdigest(Time.zone.now.to_s + title)[0..9]+"-"+"#{title}".parameterize break random_token unless Pin.where(slug: random_token).exists? end end protected def capitalize_title self.title = title.split.map(&:capitalize).join(' ') end end users_controller.rb class UsersController < ApplicationController before_filter :signed_in_user, only: [:edit, :update, :show] before_filter :correct_user, only: [:edit, :update, :show] before_filter :admin_user, only: :destroy def index if !current_user.admin? redirect_to root_path end end def menu @user = current_user end def show @user = User.find(params[:id]) @pins = @user.pins current_user.touch(:last_log_in) #sets the last log in time if [email protected]? render 'pages/info/' end end def new @user = User.new end pins_controller.rb class PinsController < ApplicationController before_filter :signed_in_user, except: [:show] # GET /pins, GET /pins.json def index #Live Feed @pins = Pin.all @featured_pins = Pin.featured_order respond_to do |format| format.html # index.html.erb format.json { render json: @pins } end end # GET /pins, GET /pins.json def show #single Pin View @pin = Pin.find_by_slug!(params[:id]) require 'uri' #this gets the photo's id from the stored uri @image_id = URI(@pin.imagesource).path.split('/').second if @pin.privacy == true #check for private pins if signed_in? if @pin.user_id == current_user.id respond_to do |format| format.html # show.html.erb format.json { render json: @pin } end else redirect_to home_path, notice: "Prohibited 1" end else redirect_to home_path, notice: "Prohibited 2" end else respond_to do |format| format.html # show.html.erb format.json { render json: @pin } end end end # GET /pins, GET /pins.json def new @pin = current_user.pins.new respond_to do |format| format.html # new.html.erb format.json { render json: @pin } end end # GET /pins/1/edit def edit @pin = current_user.pins.find_by_slug!(params[:id]) end Finally, on my index.html.erb I have: <%= render @featured_pins %>

    Read the article

  • Java curious Loop Performance

    - by user1680583
    I have a big problem while evaluate my java code. To simplify the problem I wrote the following code which produce the same curious behavior. Important is the method run() and given double value rate. For my runtime test (in the main method) I set the rate to 0.5 one times and 1.0 the other time. With the value 1.0 the if-statement will be executed in each loop iteration and with the value 0.5 the if-statement will be executed half as much. For this reason I expected longer runtime by the first case but opposite is true. Can anybody explain me this phenomenon?? The result of main: Test mit rate = 0.5 Length: 50000000, IF executions: 25000856 Execution time was 4329 ms. Length: 50000000, IF executions: 24999141 Execution time was 4307 ms. Length: 50000000, IF executions: 25001582 Execution time was 4223 ms. Length: 50000000, IF executions: 25000694 Execution time was 4328 ms. Length: 50000000, IF executions: 25004766 Execution time was 4346 ms. ================================= Test mit rate = 1.0 Length: 50000000, IF executions: 50000000 Execution time was 3482 ms. Length: 50000000, IF executions: 50000000 Execution time was 3572 ms. Length: 50000000, IF executions: 50000000 Execution time was 3529 ms. Length: 50000000, IF executions: 50000000 Execution time was 3479 ms. Length: 50000000, IF executions: 50000000 Execution time was 3473 ms. The Code public ArrayList<Byte> list = new ArrayList<Byte>(); public final int LENGTH = 50000000; public PerformanceTest(){ byte[]arr = new byte[LENGTH]; Random random = new Random(); random.nextBytes(arr); for(byte b : arr) list.add(b); } public void run(double rate){ byte b = 0; int count = 0; for (int i = 0; i < LENGTH; i++) { if(getRate(rate)){ list.set(i, b); count++; } } System.out.println("Length: " + LENGTH + ", IF executions: " + count); } public boolean getRate(double rate){ return Math.random() < rate; } public static void main(String[] args) throws InterruptedException { PerformanceTest test = new PerformanceTest(); long start, end; System.out.println("Test mit rate = 0.5"); for (int i = 0; i < 5; i++) { start=System.currentTimeMillis(); test.run(0.5); end = System.currentTimeMillis(); System.out.println("Execution time was "+(end-start)+" ms."); Thread.sleep(500); } System.out.println("================================="); System.out.println("Test mit rate = 1.0"); for (int i = 0; i < 5; i++) { start=System.currentTimeMillis(); test.run(1.0); end = System.currentTimeMillis(); System.out.println("Execution time was "+(end-start)+" ms."); Thread.sleep(500); } }

    Read the article

  • Why doesn't the default model binder update my partial view model on postback?

    - by bdnewbe
    I have a class that contains another class as one of its properties. public class SiteProperties { public SiteProperties() { DropFontFamily = "Arial, Helvetica, Sans-serif"; } public string DropFontFamily { get; set; } private ResultPageProperties m_ResultPagePropertyList; public ResultPageProperties ResultPagePropertyList { get { if (m_ResultPagePropertyList == null) m_ResultPagePropertyList = new ResultPageProperties(); return m_ResultPagePropertyList; } set { m_ResultPagePropertyList = value; } } } The second class has just one property public class ResultPageProperties { public ResultPageProperties() { ResultFontFamily = "Arial, Helvetica, Sans-serif"; } public string ResultFontFamily { get; set; } } My controller just grabs the SiteProperties and returns the view. On submit, it accepts SiteProperties and returns the same view. public class CompanyController : Controller { public ActionResult SiteOptions(int id) { SiteProperties site = new SiteProperties(); PopulateProperyDropDownLists(); return View("SiteOptions", site); } [AcceptVerbs(HttpVerbs.Post)] public ActionResult SiteOptions(SiteProperties properties) { PopulateProperyDropDownLists(); return View("SiteOptions", properties); } private void PopulateProperyDropDownLists() { var fontFamilyList = new List<SelectListItem>(); fontFamilyList.Add(new SelectListItem() { Text = "Arial, Helvetica, Sans-serif", Value = "Arial, Helvetica, Sans-serif" }); fontFamilyList.Add(new SelectListItem() { Text = "Times New Roman, Times, serif", Value = "Times New Roman, Times, serif" }); fontFamilyList.Add(new SelectListItem() { Text = "Courier New, Courier, Monospace", Value = "Courier New, Courier, Monospace" }); ViewData["FontFamilyList"] = fontFamilyList; } } The view contains a partial view that renders the ResultPageProperties Model. <% using (Html.BeginForm("SiteOptions", "Company", FormMethod.Post)) {%> <p><input type="submit" value="Submit" /></p> <div>View level input</div> <div> <label>Font family</label><br /> <%= Html.DropDownListFor(m => m.DropFontFamily, ViewData["FontFamilyList"] as List<SelectListItem>, new { Class = "UpdatesDropDownExample" })%> </div> <% Html.RenderPartial("ResultPagePropertyInput", Model.ResultPagePropertyList); %> <% } %> The partial is just <div style='margin-top: 1em;'>View level input</div> <div> <label>Font family</label><br /> <%= Html.DropDownListFor(m => m.ResultFontFamily, ViewData["FontFamilyList"] as List<SelectListItem>, new { Class = "UpdatesResultPageExample" })%> </div> OK, so when the page renders, you get "Arial, ..." in both selects. If you choose another option for both and click submit, the binder populates the SiteProperties object and passes it to the controller. However, the ResultFontFamily always contains the original value. I was expecting it to have the value the user selected. What am I missing?

    Read the article

  • AJAX Generated Select Won't Redirect

    - by James
    So, basically I have this select / drop down menu that I use AJAX to retrieve and create, though when an option is selected (so onChange) I want it to redirect! Though, this still isn't working, I don't get any errors thrown when trying, and tried to do alert() debug methods yet the alerts don't get called. jquery $("#schoolMenu").change(function() { option = $("#schoolMenu option:selected").text(); alert(option); if(option != "- Please Select -") { window.location = "http://www.itmustbecollege.com/pics/pics-from-"+$("#schoolMenu option:selected").val(); } }); This is what is used to call the AJAX // // Populate Schools // $("#state").change(function() { option = $("#state option:selected").text(); if($(this).attr("class") == "menu") { if(option != "- Please Select -") { $.ajax({ type: "GET", url: "/includes/functions.php", data: "f=school&p="+option+"&m=yes", success: function(msg) { $("#fSchool").html("<p style=\"margin-left: 20px;\">Select School:</p>"+ msg); $("#fSchool").show(); $("#school").focus(); } }); } else { $("#fSchool").html(""); $("#fSchool").hide(); } } else { if(option != "- Please Select -") { $.ajax({ type: "GET", url: "/includes/functions.php", data: "f=school&p="+option, success: function(msg) { $("#fSchool").html(msg); $("#fSchool").show(); $("#school").focus(); } }); } else { $("#fSchool").html(""); $("#fSchool").hide(); } } }); It loads perfectly, if you look at http://www.itmustbecollege.com/quotes/ on that bar where you can do "sort by" of Popular | Newest | Category | School if you hover over school a dropdown comes up, select any country and another one appears, though when that is changed nothing happens. here is the PHP for that second drop down // Get College List function getCollege($state, $m = "no", $l = "no") { // Displays Schools if($m == "yes") { $options = '<select id="schoolMenu" name="school"><option value="select" selected="selected">- Please Select -</option>'; } else if($l == "yes" || $l == "yes2") { $options = ''; } else { $options = '<select name="school"><option value="select" selected="selected">- Please Select -</option>'; } $listArray = split("\|\\\\", $list); for($i=0; $i < count($listArray); $i++) { if($m == "yes") { $options .= '<option value="'. trim(titleReplace($listArray[$i])) .'">'. trim($listArray[$i]) .'</option>'; } else if($l == "yes") { $options .= '<li><a href="/quotes/quotes-from-'. titleReplace($listArray[$i]) .'" title="'. trim($listArray[$i]) .' Quotes">'. trim($listArray[$i]) .'</a></li>'; } else if($l == "yes2") { $options .= '<li><a href="/pics/pics-from-'. titleReplace($listArray[$i]) .'" title="'. trim($listArray[$i]) .' Pictures">'. trim($listArray[$i]) .'</a></li>'; } else { $options .= '<option value="'. trim($listArray[$i]) .'">'. trim($listArray[$i]) .'</option>'; } } echo $options .='</select>'; return false; } any help would be great! EDIT: Also, the way I have those drop downs coming for the menus is a bit weird and when you hover over any other "sort by" link they disappear, this is a problem with the "sort by school" because the first select box shows the list up, and if you go and select a school then somehow float over another link it disappears, any help on how to delay that or fix that minor problem?

    Read the article

  • Trying to packetize TCP with non-blocking IO is hard! Am I doing something wrong?

    - by Ricket
    Oh how I wish TCP was packet-based like UDP is! But alas, that's not the case, so I'm trying to implement my own packet layer. Here's the chain of events so far (ignoring writing packets) Oh, and my Packets are very simply structured: two unsigned bytes for length, and then byte[length] data. (I can't imagine if they were any more complex, I'd be up to my ears in if statements!) Server is in an infinite loop, accepting connections and adding them to a list of Connections. PacketGatherer (another thread) uses a Selector to figure out which Connection.SocketChannels are ready for reading. It loops over the results and tells each Connection to read(). Each Connection has a partial IncomingPacket and a list of Packets which have been fully read and are waiting to be processed. On read(): Tell the partial IncomingPacket to read more data. (IncomingPacket.readData below) If it's done reading (IncomingPacket.complete()), make a Packet from it and stick the Packet into the list waiting to be processed and then replace it with a new IncomingPacket. There are a couple problems with this. First, only one packet is being read at a time. If the IncomingPacket needs only one more byte, then only one byte is read this pass. This can of course be fixed with a loop but it starts to get sorta complicated and I wonder if there is a better overall way. Second, the logic in IncomingPacket is a little bit crazy, to be able to read the two bytes for the length and then read the actual data. Here is the code, boiled down for quick & easy reading: int readBytes; // number of total bytes read so far byte length1, length2; // each byte in an unsigned short int (see getLength()) public int getLength() { // will be inaccurate if readBytes < 2 return (int)(length1 << 8 | length2); } public void readData(SocketChannel c) { if (readBytes < 2) { // we don't yet know the length of the actual data ByteBuffer lengthBuffer = ByteBuffer.allocate(2 - readBytes); numBytesRead = c.read(lengthBuffer); if(readBytes == 0) { if(numBytesRead >= 1) length1 = lengthBuffer.get(); if(numBytesRead == 2) length2 = lengthBuffer.get(); } else if(readBytes == 1) { if(numBytesRead == 1) length2 = lengthBuffer.get(); } readBytes += numBytesRead; } if(readBytes >= 2) { // then we know we have the entire length variable // lazily-instantiate data buffers based on getLength() // read into data buffers, increment readBytes // (does not read more than the amount of this packet, so it does not // need to handle overflow into the next packet's data) } } public boolean complete() { return (readBytes > 2 && readBytes == getLength()+2); } Basically I need feedback on my code. Please suggest any improvements. Even overhauling my entire system would be okay, if you have suggestions for how better to implement the whole thing. Book recommendations are welcome too; I love books. I just get the feeling that something isn't quite right.

    Read the article

  • Select dropdown with fixed width cutting off content in IE

    - by aaandre
    The issue: Some of the items in the select require more than the specified width of 145px in order to display fully. Firefox behavior: clicking on the select reveals the dropdown elements list adjusted to the width of the longest element. IE6 & IE7 behavior: clicking on the select reveals the dropdown elements list restricted to 145px width making it impossible to read the longer elements. The current UI requires us to fit this dropdown in 145px and have it host items with longer descriptions. Any advise on resolving the issue with IE? The top element should remain 145px wide even when the list is expanded. Thank you! The css: select.center_pull { background:#eeeeee none repeat scroll 0 0; border:1px solid #7E7E7E; color:#333333; font-size:12px; margin-bottom:4px; margin-right:4px; margin-top:4px; width:145px; } Here's the select input code (there's no definition for the backend_dropbox style at this time) <select id="select_1" class="center_pull backend_dropbox" name="select_1"> <option value="-1" selected="selected">Browse options</option> <option value="-1">------------------------------------</option> <option value="224">Option 1</option> <option value="234">Longer title for option 2</option> <option value="242">Very long and extensively descriptive title for option 3</option> </select> Full html page in case you want to quickly test in a browser: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>dropdown test</title> <style type="text/css"> <!-- select.center_pull { background:#eeeeee none repeat scroll 0 0; border:1px solid #7E7E7E; color:#333333; font-size:12px; margin-bottom:4px; margin-right:4px; margin-top:4px; width:145px; } --> </style> </head> <body> <p>Select width test</p> <form id="form1" name="form1" method="post" action=""> <select id="select_1" class="center_pull backend_dropbox" name="select_1"> <option value="-1" selected="selected">Browse options</option> <option value="-1">------------------------------------</option> <option value="224">Option 1</option> <option value="234">Longer title for option 2</option> <option value="242">Very long and extensively descriptive title for option 3</option> </select> </form> </body> </html>

    Read the article

  • Why is my program getting slower and slower ?

    - by RedWolf
    I'm using the program to send data from database to the Excel file . It works fine at the beginning and then becomes more and more slowly,finally it run out of the memory and the following error ocurrs: "java.lang.OutOfMemoryError: Java heap space...". The problem can be resolved by adding the jvm heap sapce.But the question is that it spends too much time to run out the program. After several minutes,it finished a loop with 4 seconds which can be finished with 0.5 seconds at the beginning . I can't found a solution to make it always run in a certain speed. Is it my code problem? Any clues on this? Here is the code: public void addAnswerRow(List<FinalUsers> finalUsersList,WritableWorkbook book){ if (finalUsersList.size() >0 ) { try { WritableSheet sheet = book.createSheet("Answer", 0); int colCount = 0; sheet.addCell(new Label(colCount++,0,"Number")); sheet.addCell(new Label(colCount++,0,"SchoolNumber")); sheet.addCell(new Label(colCount++,0,"District")); sheet.addCell(new Label(colCount++,0,"SchoolName")); sheet.setColumnView(1, 15); sheet.setColumnView(3, 25); List<Elements> elementsList = this.elementsManager.getObjectElementsByEduTypeAndQuestionnaireType(finalUsersList.get(0).getEducationType().getId(), this.getQuestionnaireByFinalUsersType(finalUsersList.get(0).getFinalUsersType().getId())); Collections.sort(elementsList, new Comparator<Elements>(){ public int compare(Elements o1, Elements o2) { for(int i=0; i< ( o1.getItemNO().length()>o2.getItemNO().length()? o2.getItemNO().length(): o1.getItemNO().length());i++){ if (CommonFun.isNumberic(o1.getItemNO().substring(0, o1.getItemNO().length()>3? 4: o1.getItemNO().length()-1)) && !CommonFun.isNumberic(o2.getItemNO().substring(0, o2.getItemNO().length()>3? 4: o2.getItemNO().length()-1))){ return 1; } if (!CommonFun.isNumberic(o1.getItemNO().substring(0, o1.getItemNO().length()>3? 4: o1.getItemNO().length()-1)) && CommonFun.isNumberic(o2.getItemNO().substring(0,o2.getItemNO().length()>3? 4:o2.getItemNO().length()-1))){ return -1; } if ( o1.getItemNO().charAt(i)!=o2.getItemNO().charAt(i) ){ return o1.getItemNO().charAt(i)-o2.getItemNO().charAt(i); } } return o1.getItemNO().length()> o2.getItemNO().length()? 1:-1; }}); for (Elements elements : elementsList){ sheet.addCell(new Label(colCount++,0,this.getTitlePre(finalUsersList.get(0).getFinalUsersType().getId(), finalUsersList.get(0).getEducationType().getId())+elements.getItemNO()+elements.getItem().getStem())); } int sheetRowCount =1; int sheetColCount =0; for(FinalUsers finalUsers : finalUsersList){ sheetColCount =0; sheet.addCell(new Label(sheetColCount++,sheetRowCount,String.valueOf(sheetRowCount))); sheet.addCell(new Label(sheetColCount++,sheetRowCount,finalUsers.getSchool().getSchoolNumber())); sheet.addCell(new Label(sheetColCount++,sheetRowCount,finalUsers.getSchool().getDistrict().getDistrictNumber().toString().trim())); sheet.addCell(new Label(sheetColCount++,sheetRowCount,finalUsers.getSchool().getName())); List<AnswerLog> answerLogList = this.answerLogManager.getAnswerLogByFinalUsers(finalUsers.getId()); Map<String,String> answerMap = new HashMap<String,String>(); for(AnswerLog answerLog :answerLogList ){ if (answerLog.getOptionsId() != null) { answerMap.put(answerLog.getElement().getItemNO(), this.getOptionsAnswer(answerLog.getOptionsId())); }else if (answerLog.getBlanks()!= null){ answerMap.put(answerLog.getElement().getItemNO(), answerLog.getBlanks()); }else{ answerMap.put(answerLog.getElement().getItemNO(), answerLog.getSubjectiveItemContent()); } } for (Elements elements : elementsList){ sheet.addCell(new Label(sheetColCount++,sheetRowCount,null==answerMap.get(elements.getItemNO())?"0":answerMap.get(elements.getItemNO()))); } sheetRowCount++; } book.write(); book.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (RowsExceededException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (WriteException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

    Read the article

  • How to define template directives (from an API perspective)?

    - by Ralph
    Preface I'm writing a template language (don't bother trying to talk me out of it), and in it, there are two kinds of user-extensible nodes. TemplateTags and TemplateDirectives. A TemplateTag closely relates to an HTML tag -- it might look something like div(class="green") { "content" } And it'll be rendered as <div class="green">content</div> i.e., it takes a bunch of attributes, plus some content, and spits out some HTML. TemplateDirectives are a little more complicated. They can be things like for loops, ifs, includes, and other such things. They look a lot like a TemplateTag, but they need to be processed differently. For example, @for($i in $items) { div(class="green") { $i } } Would loop over $items and output the content with the variable $i substituted in each time. So.... I'm trying to decide on a way to define these directives now. Template Tags The TemplateTags are pretty easy to write. They look something like this: [TemplateTag] static string div(string content = null, object attrs = null) { return HtmlTag("div", content, attrs); } Where content gets the stuff between the curly braces (pre-rendered if there are variables in it and such), and attrs is either a Dictionary<string,object> of attributes, or an anonymous type used like a dictionary. It just returns the HTML which gets plunked into its place. Simple! You can write tags in basically 1 line. Template Directives The way I've defined them now looks like this: [TemplateDirective] static string @for(string @params, string content) { var tokens = Regex.Split(@params, @"\sin\s").Select(s => s.Trim()).ToArray(); string itemName = tokens[0].Substring(1); string enumName = tokens[1].Substring(1); var enumerable = data[enumName] as IEnumerable; var sb = new StringBuilder(); var template = new Template(content); foreach (var item in enumerable) { var templateVars = new Dictionary<string, object>(data) { { itemName, item } }; sb.Append(template.Render(templateVars)); } return sb.ToString(); } (Working example). Basically, the stuff between the ( and ) is not split into arguments automatically (like the template tags do), and the content isn't pre-rendered either. The reason it isn't pre-rendered is because you might want to add or remove some template variables or something first. In this case, we add the $i variable to the template variables, var templateVars = new Dictionary<string, object>(data) { { itemName, item } }; And then render the content manually, sb.Append(template.Render(templateVars)); Question I'm wondering if this is the best approach to defining custom Template Directives. I want to make it as easy as possible. What if the user doesn't know how to render templates, or doesn't know that he's supposed to? Maybe I should pass in a Template instance pre-filled with the content instead? Or maybe only let him tamper w/ the template variables, and then automatically render the content at the end? OTOH, for things like "if" if the condition fails, then the template wouldn't need to be rendered at all. So there's a lot of flexibility I need to allow in here. Thoughts?

    Read the article

  • String Sharing/Reference issue with objects in Delphi

    - by jenakai123
    My application builds many objects in memory based on filenames (among other string based information). I was hoping to optimise memory usage by storing the path and filename separately, and then sharing the path between objects in the same path. I wasn't trying to look at using a string pool or anything, basically my objects are sorted so if I have 10 objects with the same path I want objects 2-10 to have their path "pointed" at object 1's path (eg object[2].Path=object[1].Path); I have a problem though, I don't believe that my objects are in fact sharing a reference to the same string after I think I am telling them to (by the object[2].Path=object[1].Path assignment). When I do an experiment with a string list and set all the values to point to the first value in the list I can see the "memory conservation" in action, but when I use objects I see absolutely no change at all, admittedly I am only using task manager (private working set) to watch for memory use changes. Here's a contrived example, I hope this makes sense. I have an object: TfileObject=class(Tobject) FpathPart: string; FfilePart: string; end; Now I create 1,000,000 instances of the object, using a new string for each one: var x: integer; MyFilePath: string; fo: TfileObject; begin for x := 1 to 1000000 do begin // create a new string for every iteration of the loop MyFilePath:=ExtractFilePath(Application.ExeName); fo:=TfileObject.Create; fo.FpathPart:=MyFilePath; FobjectList.Add(fo); end; end; Run this up and task manager says I am using 68MB of memory or something. (Note that if I allocated MyFilePath outside of the loop then I do save memory because of 1 instance of the string, but this is a contrived example and not actually how it would happen in the app). Now I want to "optimise" my memory usage by making all objects share the same instance of the path string, since it's the same value: var x: integer; begin for x:=1 to FobjectList.Count-1 do begin TfileObject(FobjectList[x]).FpathPart:=TfileObject(FobjectList[0]).FpathPart; end; end; Task Manager shows absouletly no change. However if I do something similar with a TstringList: var x: integer; begin for x := 1 to 1000000 do begin FstringList.Add(ExtractFilePath(Application.ExeName)); end; end; Task Manager says 60MB memory use. Now optimise with: var x: integer; begin for x := 1 to FstringList.Count - 1 do FstringList[x]:=FstringList[0]; end; Task Manager shows the drop in memory usage that I would expect, now 10MB. So I seem to be able to share strings in a string list, but not in objects. I am obviously missing something conceptually, in code or both! I hope this makes sense, I can really see the ability to conserve memory using this technique as I have a lot of objects all with lots of string information, that data is sorted in many different ways and I would like to be able to iterate over this data once it is loaded into memory and free some of that memory back up again by sharing strings in this way. Thanks in advance for any assistance you can offer.

    Read the article

  • Looking for suggestions on how to reuse AlertDialogs to confirm actions of contextual menus on the items of an ActivityList

    - by Ozone
    I use a ListActivity to display a list of items. The user can long-press an item in the list to display a contextual menu. This menu contains among other things an option to delete the long-pressed item. When the user selects this option, a dialog pops up asking for confirmation of the deletion. Upon confirmation, the item is deleted from the list. I would like to reuse the AlertDialog as much as possible. My attempts at using onPrepareDialog(int, View, Bundle) have been defeated by the fact that the Bundle is not passed to the DialogInterface.OnClickListener. I end up having to recreate a listener on every invocation. I see several ways to solve this: recreate the dialog on every occasion (pros: simple, cons: wasteful) keep the DialogInterface.OnClickListener in a field on the ListActivity and keep the item to be deleted as a field of the listener. (pros: no memory waste, cons: need to manage state). Q: is this safe? have onPrepareDialog update the title, and bind new View.OnClickListeners on the buttons of the AlertDialog. (pros: limit waste, cons: new View.OnClickListener on every invocation). If DialogInterface.OnClickListener accepted a Bundle, I wouldn't have to jump through hoops to keep track of the item being deleted. This is not a blocker, but I would love to see an elegant solution. I would love to hear your suggestions :) Here is the code for option #1, if you want to play with this: public class Example extends ListActivity { private static final int CONFIRM_DELETE_DIALOG = 1; private static final String POSITION_KEY = "position"; private ArrayAdapter<String> mAdapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mAdapter = new ArrayAdapter<String>( this, android.R.layout.simple_list_item_1, new String[] { "one", "two" }); setListAdapter(mAdapter); registerForContextMenu(getListView()); } @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); getMenuInflater().inflate(R.menu.my_lovely_menu, menu); } @Override public boolean onContextItemSelected(MenuItem item) { AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo(); switch (item.getItemId()) { case R.id.delete_item: Bundle bundle = new Bundle(); bundle.putInt(POSITION_KEY, info.position); showDialog(CONFIRM_DELETE_DIALOG, bundle); return true; default: return super.onContextItemSelected(item); } } @Override protected Dialog onCreateDialog(int id, Bundle args) { switch (id) { case CONFIRM_DELETE_DIALOG: final int position = args.getInt(POSITION_KEY); AlertDialog.Builder builder = new AlertDialog.Builder(); builder.setCancelable(false); builder.setTitle(String.format( getString(R.string.confirm_delete), mAdapter.getItem(position))); DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { switch (which) { case DialogInterface.BUTTON_POSITIVE: mAdapter.remove(mAdapter.getItem(position)); // Dismiss the dialog to ensure OnDismissListeners are notified. dialog.dismiss(); break; case DialogInterface.BUTTON_NEGATIVE: // Cancel the dialog to ensure OnCancelListeners are notified. dialog.cancel(); break; } // Remove the dialog so it is re-created next time it is required. removeDialog(CONFIRM_DELETE_DIALOG); } }; builder.setPositiveButton(android.R.string.yes, listener); builder.setNegativeButton(android.R.string.no, listener); return builder.create(); default: return super.onCreateDialog(id, args); } } }

    Read the article

  • javascript won't execute nested for loop

    - by mcdwight6
    thanks in advance for all your help! i'm fairly new to javascript, but i have a fairly strong background in java, so i thought i would try it out on this project i'm working on. essentially, what i'm trying to do is read data from an xml file and create the html code for the page i'm making. i used the script from w3schools found here. I've altered it and gotten it to pull the data from my own xml and even to do the more basic generation of the html code i need. Here's the html i'm using inside <script> tags: var s = swDoc.getElementsByTagName("planet"); var plShowsArr = s[i].getElementsByTagName("show"); var plGamesArr = s[i].getElementsByTagName("videoGame"); for (i=0;i<s.length;i++) { // test section all works document.write("<div><table border = \"1\">"); document.write("<tr><td>"+ s[i].getElementsByTagName("showText")[0].childNodes[0].nodeValue + "</td><td>" + s[i].getElementsByTagName("showUrl")[0].childNodes[0].nodeValue + "</td></tr>"); document.write("<tr><td>" + s[i].getElementsByTagName("gameText")[0].childNodes[0].nodeValue + "</td><td>" + s[i].getElementsByTagName("gameUrl")[0].childNodes[0].nodeValue + "</td></tr>"); document.write("</tr></table></div>"); // end test section document.write("<div class=\"appearances-row\"><ol class=\"shows\">shows list"); for(j=0;j<plShows.length;j++){ document.write("nested for"); var showUrl = s[i].getElementsByTagName("showUrl")[j].childNodes[0].nodeValue; var showText = s[i].getElementByTagName("showText")[j].childNodes[0].nodeValue; document.write("<li><a href=\""+showUrl+"\">"+showText+"</a></li>"); } the code breaks at the nested for loop at the end, where it finished the document.write and prints "shows list" to the page, but then never gets to the document.write inside. if it helps, the xml contains a list of planets from the star wars universe organized like this: <planets> <planet> <planetName>planet</planetName> <description>some text</description> <appearances> <show> <showUrl>url</showUrl> <showText>hyperlink text</showText> </show> <videoGame> <gameUrl>url</gameUrl> <gameText>hyperlink text</gameText> </videoGame> </appearances> <locationsOfInterest> <location>location name</location> </locationsOfInterest> <famousCharactersRelatedTo> <character>a character</character> </famousCharactersRelatedTo> <externalLinks> <link> <linkUrl>url</linkUrl> <linkText>hyperlink text</linkText> </link> </externalLinks> </planet>

    Read the article

  • Haskell: monadic takeWhile?

    - by Mark Rushakoff
    I have some functions written in C that I call from Haskell. These functions return IO (CInt). Sometimes I want to run all of the functions regardless of what any of them return, and this is easy. For sake of example code, this is the general idea of what's happening currently: Prelude> let f x = print x >> return x Prelude> mapM_ f [0..5] 0 1 2 3 4 5 Prelude> I get my desired side effects, and I don't care about the results. But now I need to stop execution immediately after the first item that doesn't return my desired result. Let's say a return value of 4 or higher requires execution to stop - then what I want to do is this: Prelude> takeWhile (<4) $ mapM f [0..5] Which gives me this error: <interactive:1:22: Couldn't match expected type `[b]' against inferred type `IO a' In the first argument of `mapM', namely `f' In the second argument of `($)', namely `mapM f ([0 .. 5])' In the expression: takeWhile (< 4) $ mapM f ([0 .. 5]) And that makes sense to me - the result is still contained in the IO monad, and I can't just compare two values contained in the IO monad. I know this is precisely the purpose of monads -- chaining results together and discarding operations when a certain condition is met -- but is there an easy way to "wrap up" the IO monad in this case to stop executing the chain upon a condition of my choosing, without writing an instance of MonadPlus? Can I just "unlift" the values from f, for the purposes of the takeWhile? Is this a solution where functors fit? Functors haven't "clicked" with me yet, but I sort of have the impression that this might be a good situation to use them. Update: @sth has the closest answer to what I want - in fact, that's almost exactly what I was going for, but I'd still like to see whether there is a standard solution that isn't explicitly recursive -- this is Haskell, after all! Looking back on how I worded my question, now I can see that I wasn't clear enough about my desired behavior. The f function I used above for an example was merely an example. The real functions are written in C and used exclusively for their side effects. I can't use @Tom's suggestion of mapM_ f (takeWhile (&lt;4) [0..5]) because I have no idea whether any input will really result in success or failure until executed. I don't actually care about the returned list, either -- I just want to call the C functions until either the list is exhausted or the first C function returns a failure code. In C-style pseudocode, my behavior would be: do { result = function_with_side_effects(input_list[index++]); } while (result == success && index < max_index); So again, @sth's answer performs the exact behavior that I want, except that the results may (should?) be discarded. A dropWhileM_ function would be equivalent for my purposes. Why isn't there a function like that or takeWhileM_ in Control.Monad? I see that there was a similar discussion on a mailing list, but it appears that nothing has come of that.

    Read the article

  • Templates, interfaces (multiple inheritance) and static functions (named constructors)

    - by fledgling Cxx user
    Setup I have a graph library where I am trying to decompose things as much as possible, and the cleanest way to describe it that I found is the following: there is a vanilla type node implementing only a list of edges: class node { public: int* edges; int edge_count; }; Then, I would like to be able to add interfaces to this whole mix, like so: template <class T> class node_weight { public: T weight; }; template <class T> class node_position { public: T x; T y; }; and so on. Then, the actual graph class comes in, which is templated on the actual type of node: template <class node_T> class graph { protected: node_T* nodes; public: static graph cartesian(int n, int m) { graph r; r.nodes = new node_T[n * m]; return r; } }; The twist is that it has named constructors which construct some special graphs, like a Cartesian lattice. In this case, I would like to be able to add some extra information into the graph, depending on what interfaces are implemented by node_T. What would be the best way to accomplish this? Possible solution I thought of the following humble solution, through dynamic_cast<>: template <class node_T, class weight_T, class position_T> class graph { protected: node_T* nodes; public: static graph cartesian(int n, int m) { graph r; r.nodes = new node_T[n * m]; if (dynamic_cast<node_weight<weight_T>>(r.nodes[0]) != nullptr) { // do stuff knowing you can add weights } if (dynamic_cast<node_position<positionT>>(r.nodes[0]) != nullptr) { // do stuff knowing you can set position } return r; } }; which would operate on node_T being the following: template <class weight_T, class position_T> class node_weight_position : public node, public node_weight<weight_T>, public node_position<position_T> { // ... }; Questions Is this -- philosophically -- the right way to go? I know people don't look nicely at multiple inheritance, though with "interfaces" like these it should all be fine. There are unfortunately problems with this. From what I know at least, dynamic_cast<> involves quite a bit of run-time overhead. Hence, I run into a problem with what I had solved earlier: writing graph algorithms that require weights independently of whether the actual node_T class has weights or not. The solution with this 'interface' approach would be to write a function: template <class node_T, class weight_T> inline weight_T get_weight(node_T const & n) { if (dynamic_cast<node_weight<weight_T>>(n) != nullptr) { return dynamic_cast<node_weight<weight_T>>(n).weight; } return T(1); } but the issue with it is that it works using run-time information (dynamic_cast), yet in principle I would like to decide it at compile-time and thus make the code more efficient. If there is a different solution that would solve both problems, especially a cleaner and better one than what I have, I would love to hear about it!

    Read the article

< Previous Page | 703 704 705 706 707 708 709 710 711 712 713 714  | Next Page >