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  • adjusting table content with javascript by enumerating rows

    - by Tom
    I have a table row with 4 columns on my ecommerce site and I want to replace the content of 1st column if total amount in last column (TD class "total") is over 10 EUR. How can I do this with javascript only, I guess somehow to enumerate through the table rows and look for a correct row (one with the last column class as total) and then access the content of 1st column on this row but how?

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  • Configuring web.xml for webservices and servlet.

    - by Win Man
    Hi, I am new to Restlets. Trying to configure the web.xml (on JBoss). I have 2 entries, one for a servlet (got nothing to do with webservices) other for webservices, using Restlet. Here are the entries.. <servlet> <servlet-name>AuthenticationServlet</servlet-name> <servlet-class>com.safeid.web.server.api.servlet.AuthenticationServlet</servlet-class> <load-on-startup>2</load-on-startup> </servlet> <servlet-mapping> <servlet-name>AuthenticationServlet</servlet-name> <url-pattern>/authenticate/*</url-pattern> </servlet-mapping> <!-- Start of Entries for the REST Web Services. --> <context-param> <param-name>org.restlet.application</param-name> <param-value>com.safeid.web.server.SafeIDRouterApplication</param-value> </context-param> <servlet> <servlet-name>RestletServlet</servlet-name> <servlet-class>com.noelios.restlet.ext.servlet.ServerServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>RestletServlet</servlet-name> <url-pattern>/*</url-pattern> </servlet-mapping> <!-- END of Entries for the REST Web Services.--> Both don't work together. In the above setup the Restlet works. However when I change the RestletServlet /* to something like <servlet-mapping> <servlet-name>RestletServlet</servlet-name> <url-pattern>/credential/*</url-pattern> </servlet-mapping> the Restlet stop working and the AuthenticationServlet works fine. What am I missing here?

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  • How to customize android analog clock widget through configuration screen

    - by michJ
    I'm trying to develop my own analog clock widget on the home screen. It's based on the stock ICS analog clock widget, but when added to the homescreen, my widget opens a configuration screen first. On this screen you can choose the color you want the clock to be (through a colorpicker dialog). You also see a preview of the clock in the chosen color on this screen. (See picture). My problem is changing the color of the widget on the home screen to the chosen color (when you hit the apply button). I have three .png files that I use for the dial, hour hand and minute hand. I color them using this code in my widgetconfig class: Drawable dial = getResources().getDrawable(R.drawable.clockbackground); dial.setColorFilter(color, PorterDuff.Mode.MULTIPLY); //hour Drawable hour = getResources().getDrawable(R.drawable.hourhand); hour.setColorFilter(color, PorterDuff.Mode.MULTIPLY); //minute Drawable min = getResources().getDrawable(R.drawable.minutehand); min.setColorFilter(color, PorterDuff.Mode.MULTIPLY); // clock AnalogClock clockpreview = (AnalogClock) findViewById(R.id.ACconfig); clockpreview.setBackgroundDrawable(dial); This works fine because I can find the AnalogClock since it's in the layout xml file of the configuration screen, which I set in the OnCreate() through setContentView(). The problem is that for the clock widget on my screen I have to use RemoteViews. So I tried setting the new background of the clock widget through RemoteViews. But RemoteViews seems too limited to do this. I need something like setTextViewText() but then for the background of my analog clock widget, like for example: RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.clockwidget); views.setAnalogClockBackgroundDrawable(dial); The clock widget background seems sort of unchangeable. How can I recolor my clockwidget on homescreen in widgetconfig class? There must be a way because it seems so easy to do at first... My project consists of the widget config class and clockwidget class, widgetconfig.xml, clockwidget.xml, and widget_info.xml (for appwidgetprovider).

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  • Design Technique: How to design a complex system for processing orders, products and units.

    - by Shyam
    Hi, Programming is fun: I learned that by trying out simple challenges, reading up some books and following some tutorials. I am able to grasp the concepts of writing with OO (I do so in Ruby), and write a bit of code myself. What bugs me though is that I feel re-inventing the wheel: I haven't followed an education or found a book (a free one that is) that explains me the why's instead of the how's, and I've learned from the A-team that it is the plan that makes it come together. So, armed with my nuby Ruby skills, I decided I wanted to program a virtual store. I figured out the following: My virtual Store will have: Products and Services Inventories Orders and Shipping Customers Now this isn't complex at all. With the help of some cool tools (CMapTools), I drew out some concepts, but quickly enough (thanks to my inferior experience in designing), my design started to bite me. My very first product-line were virtual "laptops". So, I created a class (Ruby): class Product attr_accessor :name, :price def initialize(name, price) @name = name @price = price end end which can be instantiated by doing (IRb) x = Product.new("Banana Pro", 250) Since I want my virtual customers to be able to purchase more than one product, or various types, I figured out I needed some kind of "Order" mechanism. class Order def initialize(order_no) @order_no = order_no @line_items = [] end def add_product(myproduct) @line_items << myproduct end def show_order() puts @order_no @line_items.each do |x| puts x.name.to_s + "\t" + x.price.to_s end end end that can be instantiated by doing (IRb) z = Order.new(1234) z.add_product(x) z.show_order Splendid, I have now a very simple ordering system that allows me to add products to an order. But, here comes my real question. What if I have three models of my product (economy, business, showoff)? Or have my products be composed out of separate units (bigger screen, nicer keyboard, different OS)? Surely I could make them three separate products, or add complexity to my product class, but I am looking for are best practices to design a flexible product object that can be used in the real world, to facilitate a complex system. My apologies if my grammar and my spelling are with error, as english is not my first language and I took the time to check as far I could understand and translate properly! Thank you for your answers, comments and feedback!

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  • creating dynamic rich:dropdownmenu

    - by santhana sankar
    MethodExpression methodExpression = application.getExpressionFactory().createMethodExpression( FacesContext.getCurrentInstance().getELContext(), "#{PrismBacking.onItemClick}", null, new Class[] { ActionEvent.class }); menuItem.setActionExpression(methodExpression); I created a dynamic drop down as above my creating action listener but the listener was not called. I included the method inside the getter of dropdown in backing bean. Do I have to configure the action listener in any of the config files. kindly help.

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  • Getting jQuery slideshow animation to stop on click

    - by hollyb
    I have a slide show built with jQuery that pauses on hover. It has a group of thumbnails sitting on top of the image that advances the image when clicked, otherwise the slideshow just auto-rotates through all the images. There is also a +/- to expand and contract a caption related to each image. I want to have the slideshow's automatic advancing to stop if one of the thumbnails is clicked, or the +/-. Basically, just stop whenever a user clicks anywhere within the gallery (div class=".homeImg"). I'm having a major brain fart in getting this working properly and could use some advice. Here's the jQuery: $(document).ready(function() { $(".main_image .desc").show(); //Show image info $(".main_image .block").animate({ opacity: 0.85 }, 1 ); //Set Opacity //Click and Hover events for thumbnail list $(".image_thumb ul li:first").addClass('active'); // * Adds a class 'last' to the last li to let the rotator know when to return to the first $(".image_thumb ul li:last").addClass('last'); $(".image_thumb ul li").click(function(){ //Set Variables var imgAlt = $(this).find('img').attr("alt"); //Get Alt Tag of Image var imgTitle = $(this).find('a').attr("href"); //Get Main Image URL var imgDesc = $(this).find('.block').html(); //Get HTML of block var imgDescHeight = $(".main_image").find('.block').height(); //Calculate height of block if ($(this).is(".active")) { //If it's already active, then… return false; // Don't click through } else { //Animate $(".main_image img").animate({ opacity: 0}, 800 ); $(".main_image .block").animate({ opacity: 0, marginBottom: -imgDescHeight }, 800, function() { $(".main_image .block").html(imgDesc).animate({ opacity: 0.85, marginBottom: "0" }, 250 ); $(".main_image img").attr({ src: imgTitle , alt: imgAlt}).animate({ opacity: 1}, 250 ); }); } $(".image_thumb ul li").removeClass('active'); //Remove class of 'active' on all lists $(this).addClass('active'); //add class of 'active' on this list only return false; }) .hover(function(){ $(this).addClass('hover'); }, function() { $(this).removeClass('hover'); }); //Toggle teaser $("a.collapse").click(function(){ $(".main_image .block").slideToggle(); $("a.collapse").toggleClass("show"); return false; // added to remove # browser jump }); // If we are hovering over the image area, pause the clickNext function pauseClickNext = false; $(".homeImg").hover( function () { pauseClickNext = true; }, function () { pauseClickNext = false; } ); // Define function to click the next li var clickNext = function(){ if(!pauseClickNext) { /// find the next li after .active var $next_li = $("li.active").next("li"); if($("li.active").hasClass("last") ){ $(".image_thumb ul li:first").trigger("click"); } else { $next_li.trigger("click"); } } }; // Time between image transition setInterval(clickNext, 6000); });

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  • "Can't mass-assign protected attributes" with nested protected models

    - by JohnnyFive
    I'm having a hell of a time trying to get this nested model working. I've tried all manner of pluralization/singular, removing the attr_accessible altogether, and who knows what else. restaurant.rb: # == RESTAURANT MODEL # # Table name: restaurants # # id :integer not null, primary key # name :string(255) # created_at :datetime not null # updated_at :datetime not null # class Restaurant < ActiveRecord::Base attr_accessible :name, :job_attributes has_many :jobs has_many :users, :through => :jobs has_many :positions accepts_nested_attributes_for :jobs, :allow_destroy => true validates :name, presence: true end job.rb: # == JOB MODEL # # Table name: jobs # # id :integer not null, primary key # restaurant_id :integer # shortname :string(255) # user_id :integer # created_at :datetime not null # updated_at :datetime not null # class Job < ActiveRecord::Base attr_accessible :restaurant_id, :shortname, :user_id belongs_to :user belongs_to :restaurant has_many :shifts validates :name, presence: false end restaurants_controller.rb: class RestaurantsController < ApplicationController before_filter :logged_in, only: [:new_restaurant] def new @restaurant = Restaurant.new @user = current_user end def create @restaurant = Restaurant.new(params[:restaurant]) if @restaurant.save flash[:success] = "Restaurant created." redirect_to welcome_path end end end new.html.erb: <% provide(:title, 'Restaurant') %> <%= form_for @restaurant do |f| %> <%= render 'shared/error_messages' %> <%= f.label "Restaurant Name" %> <%= f.text_field :name %> <%= f.fields_for :job do |child_f| %> <%= child_f.label "Nickname" %> <%= child_f.text_field :shortname %> <% end %> <%= f.submit "Done", class: "btn btn-large btn-primary" %> <% end %> Output Parameters: {"utf8"=>"?", "authenticity_token"=>"DjYvwkJeUhO06ds7bqshHsctS1M/Dth08rLlP2yQ7O0=", "restaurant"=>{"name"=>"The Pink Door", "job"=>{"shortname"=>"PD"}}, "commit"=>"Done"} The error i'm receiving is: ActiveModel::MassAssignmentSecurity::Error in RestaurantsController#create Cant mass-assign protected attributes: job Rails.root: /home/johnnyfive/Dropbox/Projects/sa Application Trace | Framework Trace | Full Trace app/controllers/restaurants_controller.rb:11:in `new' app/controllers/restaurants_controller.rb:11:in `create' Anyone have ANY clue how to get this to work? Thanks!

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  • Scaffolding Extensions: NoMethodError

    - by marienbad
    Not sure if many people are familiar with Scaffolding Extensions for Ruby, but I've looked through their docs, forums, and even the source code of the Heroku test site, and not found an answer. I made a basic Sinatra app and followed right from the RDoc's instructions: require 'scaffolding_extensions' require 'sinatra/base' class Thingy < Sinatra::Base scaffold_all_models end gives undefined method 'scaffold_all_models' for Thingy:Class (NoMethodError) and I know Scaffolding Extensions is loadable because I can successfully set some config variables in its classes.

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  • Scala passing type parameters to object

    - by Shahzad Mian
    In Scala v 2.7.7 I have a file with class Something[T] extends Other { } object Something extends OtherConstructor[Something] { } This throws the error: class Something takes type parameters object Something extends OtherConstructor[Something] { However, I can't do this object Something[T] extends OtherConstructor[Something[T]] { } It throws an error: error: ';' expected but '[' found. Is it possible to send type parameters to object? Or should I change and simply use Otherconstructor

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  • How do I turn off a custom IValueConverter at design time?

    - by Jonathan Allen
    How do I turn off a custom IValueConverter at design time? Basically I want to write this: Public Class MethodBinder Implements IValueConverter Public Function Convert(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As CultureInfo) As Object Implements IValueConverter.Convert If [DESIGN_TIME] Then Return Nothing If value IsNot Nothing Then Return CallByName(value, CStr(parameter), CallType.Method) Return Nothing End Function Public Function ConvertBack(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As CultureInfo) As Object Implements IValueConverter.ConvertBack Throw New NotSupportedException End Function End Class

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  • Unique_ptr compiler errors

    - by Godric Seer
    I am designing and entity-component system for a project, and C++ memory management is giving me a few issues. I just want to make sure my design is legitimate. So to start I have an Entity class which stores a vector of Components: class Entity { private: std::vector<std::unique_ptr<Component> > components; public: Entity() { }; void AddComponent(Component* component) { this -> components.push_back(std::unique_ptr<Component>(component)); } ~Entity(); }; Which if I am not mistaken means that when the destructor is called (even the default, compiler created one), the destructor for the Entity, will call ~components, which will call ~std::unique_ptr for each element in the vector, and lead to the destruction of each Component, which is what I want. The component class has virtual methods, but the important part is its constructor: Component::Component(Entity parent) { parent.addComponent(this) // I am not sure if this would work like I expect // Other things here } As long as passing this to the method works, this also does what I want. My confusion is in the factory. What I want to do is something along the lines of: std::shared_ptr<Entity> createEntity() { std::shared_ptr<Entity> entityPtr(new Entity()); new Component(*parent); // Initialize more, and other types of Components return entityPtr; } Now, I believe that this setup will leave the ownership of the Component in the hands of its Parent Entity, which is what I want. First a small question, do I need to pass the entity into the Component constructor by reference or pointer or something? If I understand C++, it would pass by value, which means it gets copied, and the copied entity would die at the end of the constructor. The second, and main question is that code based on this sample will not compile. The complete error is too large to print here, however I think I know somewhat of what is going on. The compiler's error says I can't delete an incomplete type. My Component class has a purely virtual destructor with an implementation: inline Component::~Component() { }; at the end of the header. However since the whole point is that Component is actually an interface. I know from here that a complete type is required for unique_ptr destruction. The question is, how do I work around this? For reference I am using gcc 4.4.6.

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  • std::ostream interface to an OLE IStream

    - by PaulH
    I have a Visual Studio 2008 C++ application using IStreams. I would like to use the IStream connection in a std::ostream. Something like this: IStream* stream = /*create valid IStream instance...*/; IStreamBuf< WIN32_FIND_DATA > sb( stream ); std::ostream os( &sb ); WIN32_FIND_DATA d = { 0 }; // send the structure along the IStream os << d; To accomplish this, I've implemented the following code: template< class _CharT, class _Traits > inline std::basic_ostream< _CharT, _Traits >& operator<<( std::basic_ostream< _CharT, _Traits >& os, const WIN32_FIND_DATA& i ) { const _CharT* c = reinterpret_cast< const _CharT* >( &i ); const _CharT* const end = c + sizeof( WIN32_FIND_DATA ) / sizeof( _CharT ); for( c; c < end; ++c ) os << *c; return os; } template< typename T > class IStreamBuf : public std::streambuf { public: IStreamBuf( IStream* stream ) : stream_( stream ) { setp( reinterpret_cast< char* >( &buffer_ ), reinterpret_cast< char* >( &buffer_ ) + sizeof( buffer_ ) ); }; virtual ~IStreamBuf() { sync(); }; protected: traits_type::int_type FlushBuffer() { int bytes = std::min< int >( pptr() - pbase(), sizeof( buffer_ ) ); DWORD written = 0; HRESULT hr = stream_->Write( &buffer_, bytes, &written ); if( FAILED( hr ) ) { return traits_type::eof(); } pbump( -bytes ); return bytes; }; virtual int sync() { if( FlushBuffer() == traits_type::eof() ) return -1; return 0; }; traits_type::int_type overflow( traits_type::int_type ch ) { if( FlushBuffer() == traits_type::eof() ) return traits_type::eof(); if( ch != traits_type::eof() ) { *pptr() = ch; pbump( 1 ); } return ch; }; private: /// data queued up to be sent T buffer_; /// output stream IStream* stream_; }; // class IStreamBuf Yes, the code compiles and seems to work, but I've not had the pleasure of implementing a std::streambuf before. So, I'd just like to know if it's correct and complete. Thanks, PaulH

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  • Formtastic with Mongoid embedded_in relations

    - by miah
    Is there any quick way to make a form for embeds_many-embedded_in relation? I have the following: class Team include Mongoid::Document field :name, :type => String embeds_many :players end class Player include Mongoid::Document embedded_in :team, :inverse_of => :players field :name, :type => String end I want to create a form for team with embedded editing for players. Seen https://github.com/bowsersenior/formtastic_with_mongoid_tutorial but "TODO" there.

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  • Superfish drag-drop problem

    - by HasanGursoy
    Hi, I've created a menu with jQuery superfish but I'm having problem when drag-drop on one of the top menu items. .sfHover class is added when pressed on a item and if this item is not clicked and dropped item remains with .sfHover class and because of this, background of the item is changed. How can I fix this problem? Here is the demo.

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  • How to access static members in a Velocity template?

    - by matt b
    I'm not sure if there is a way to do this in Velocity or not: I have a User POJO which a property named Status, which looks like an enum (but it is not, since I am stuck on Java 1.4), the definition looks something like this: public class User { // default status to User private Status status = Status.USER; public void setStatus(Status status) { this.status = status; } public Status getStatus() { return status; } And Status is a static inner class: public static final class Status { private String statusString; private Status(String statusString) { this.statusString = statusString; } public final static Status USER = new Status("user"); public final static Status ADMIN = new Status("admin"); public final static Status STATUS_X = new Status("blah"); //.equals() and .hashCode() implemented as well } With this pattern, a user status can easily be tested in a conditional such as if(User.Status.ADMIN.equals(user.getStatus())) ... ... without having to reference any constants for the status ID, any magic numbers, etc. However, I can't figure out how to test these conditionals in my Velocity template with VTL. I'd like to just print a simple string based upon the user's status, such as: Welcome <b>${user.name}</b>! <br/> <br/> #if($user.status == com.company.blah.User.Status.USER) You are a regular user #elseif($user.status == com.company.blah.User.Status.ADMIN) You are an administrator #etc... #end But this throws an Exception that looks like org.apache.velocity.exception.ParseErrorException: Encountered "User" at webpages/include/dashboard.inc[line 10, column 21] Was expecting one of: "[" ... From the VTL User Guide, there is no mention of accessing a Java class/static member directly in VTL, it appears that the right hand side (RHS) of a conditional can only be a number literal, string literal, property reference, or method reference. So is there any way that I can access static Java properties/references in a Velocity template? I'm aware that as a workaround, I could embed the status ID or some other identifier as a reference in my controller (this is a web MVC application using Velocity as the View technology), but I strongly do not want to embed any magic numbers or constants in the view layer.

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  • Generic Dictionary C#

    - by pm_2
    I have a class that inherits from a generic dictionary as follows: Class myClass : System.Collections.Generic.Dictionary<int, Object> I have added a list of values to this in a particular order, but I now wish to change that order. Is there any way (without removing and re-adding) that I could effectively re-index the values; so change the object at index 1 to now be at index 10 for example? For example, this doesn't work: myClass[1].Index = 10;

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  • Difficulty adding widgets to django form.

    - by codingJoe
    I have a django app that tracks activities that can benefit a classroom. Using the django examples, I was able to build a form to enter this data. But when I try to add widgets to that form, things get tricky. What I want is a calendar widget that lets the user enter the 'activity_date' field using a widget. If I use Admin interface. The AdminDateWidget works fine. however. This particular user isn't allowed access to the admin interface so I need a different way to present this widget. Also I couldn't figure out how to make the bring the admin widget over into non-admin pages. So I tried a custom widget. This is the first custom widget I've built, so I'm not quite sure what is supposed to be going on here. Any Expert Advice? How do I get my date widget to work? # The Model class Activity(models.Model): activity_date = models.DateField() activity_type = models.CharField(max_length=50, choices=ACTIVITY_TYPES) activity_description = models.CharField(max_length=200) activity_duration= models.DecimalField(decimal_places=2, max_digits=4) est_attendance = models.IntegerField("Estimated attendance") # The Form class ActivityForm(forms.ModelForm): # The following line causes lockup if enabled. # With the DateTimeWidget removed, the form functions correctly except that there is no widget. #activity_date = forms.DateField(label=_('Date'), widget=DateTimeWidget) ##!!! Point of Error !!! class Meta: model = Activity fields = ('activity_date', 'activity_type', 'activity_description', 'activity_duration', 'est_attendance') def __init__(self, *args, **kwargs): super(ActivityForm, self).__init__(*args, **kwargs) instance = getattr(self, 'instance', None) edit_aid = kwargs.get('edit_aid', False) # On a different approach, the following also didn't work. #self.fields['activity_date'].widget = widgets.AdminDateWidget() # The Widget # Example referenced: http://djangosnippets.org/snippets/391/ calbtn = u""" <button id="calendar-trigger">...</button> <img src="%s/site_media/images/icon_calendar.gif" alt="calendar" id="%s_btn" style="cursor: pointer; border: 1px solid #8888aa;" title="Select date and time" onmouseover="this.style.background='#444444';" onmouseout="this.style.background=''" /> <script type="text/javascript"> Calendar.setup({ trigger : "calendar-trigger", inputField : "%s" }); </script>""" class DateTimeWidget(forms.widgets.TextInput): dformat = '%Y-%m-%d %H:%M' def render(self, name, value, attrs=None): print "DTWgt render name=%s, value=%s" % name, value if value is None: value = '' final_attrs = self.build_attrs(attrs, type=self.input_type, name=name) if value != '': try: final_attrs['value'] = \ force_unicode(value.strftime(self.dformat)) except: final_attrs['value'] = \ force_unicode(value) if not final_attrs.has_key('id'): final_attrs['id'] = u'%s_id' % (name) id = final_attrs['id'] jsdformat = self.dformat #.replace('%', '%%') cal = calbtn % (settings.MEDIA_URL, id, id, jsdformat, id) a = u'<input%s />%s' % (forms.util.flatatt(final_attrs), cal) print "render return %s " % a return mark_safe(a) def value_from_datadict(self, data, files, name): print "DTWgt value_from_datadict" dtf = forms.fields.DEFAULT_DATETIME_INPUT_FORMATS empty_values = forms.fields.EMPTY_VALUES value = data.get(name, None) if value in empty_values: return None if isinstance(value, datetime.datetime): return value if isinstance(value, datetime.date): return datetime.datetime(value.year, value.month, value.day) for format in dtf: try: return datetime.datetime(*time.strptime(value, format)[:6]) except ValueError: continue return None

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  • PHP Doctrine: generation problem?

    - by ropstah
    I'm generating models from my Mysql db. It generates a foreign key collection properly, but not the other way around... Is this supposed to be 'by-design', or am i doing something wrong? pseudo code alert User: UserId pk LocationId fk //User location Location LocationId pk UserId fk //Location owner Generated code: class User() { hasMany('Location') //for locations owned by the user //BUT NOT THIS ONE: //hasOne('Location_1') //for current location of user } class Location() { hasMany('User') //for users which are on that location //AND NOT THIS ONE //hasOne('User_1') //for location owner }

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  • question about book example - Java Concurrency in Practice, Listing 4.12

    - by mike
    Hi, I am working through an example in Java Concurrency in Practice and am not understanding why a concurrent-safe container is necessary in the following code. I'm not seeing how the container "locations" 's state could be modified after construction; so since it is published through an 'unmodifiableMap' wrapper, it appears to me that an ordinary HashMap would suffice. EG, it is accessed concurrently, but the state of the map is only accessed by readers, no writers. The value fields in the map are syncronized via delegation to the 'SafePoint' class, so while the points are mutable, the keys for the hash, and their associated values (references to SafePoint instances) in the map never change. I think my confusion is based on what precisely the state of the collection is in the problem. Thanks!! -Mike Listing 4.12, Java Concurrency in Practice, (this listing available as .java here, and also in chapter form via google) /////////////begin code @ThreadSafe public class PublishingVehicleTracker { private final Map<String, SafePoint> locations; private final Map<String, SafePoint> unmodifiableMap; public PublishingVehicleTracker( Map<String, SafePoint> locations) { this.locations = new ConcurrentHashMap<String, SafePoint>(locations); this.unmodifiableMap = Collections.unmodifiableMap(this.locations); } public Map<String, SafePoint> getLocations() { return unmodifiableMap; } public SafePoint getLocation(String id) { return locations.get(id); } public void setLocation(String id, int x, int y) { if (!locations.containsKey(id)) throw new IllegalArgumentException( "invalid vehicle name: " + id); locations.get(id).set(x, y); } } // monitor protected helper-class @ThreadSafe public class SafePoint { @GuardedBy("this") private int x, y; private SafePoint(int[] a) { this(a[0], a[1]); } public SafePoint(SafePoint p) { this(p.get()); } public SafePoint(int x, int y) { this.x = x; this.y = y; } public synchronized int[] get() { return new int[] { x, y }; } public synchronized void set(int x, int y) { this.x = x; this.y = y; } } ///////////end code

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  • Can I call make runtime decided method calls in Java?

    - by Catalin Marin
    I know there is an invoke function that does the stuff, I am overall interested in the "correctness" of using such a behavior. My issue is this: I have a Service Object witch contains methods which I consider services. What I want to do is alter the behavior of those services without later intrusion. For example: class MyService { public ServiceResponse ServeMeDonuts() { do stuff... return new ServiceResponse(); } after 2 months I find out that I need to offer the same service to a new client app and I also need to do certain extra stuff like setting a flag, or make or updating certain data, or encode the response differently. What I can do is pop it up and throw down some IFs. In my opinion this is not good as it means interaction with tested code and may result in un wanted behaviour for the previous service clients. So I come and add something to my registry telling the system that the "NewClient" has a different behavior. So I'll do something like this: public interface Behavior { public void preExecute(); public void postExecute(); } public class BehaviorOfMyService implements Behavior{ String method; String clientType; public void BehaviorOfMyService(String method,String clientType) { this.method = method; this.clientType = clientType; } public void preExecute() { Method preCall = this.getClass().getMethod("pre" + this.method + this.clientType); if(preCall != null) { return preCall.invoke(); } return false; } ...same for postExecute(); public void preServeMeDonutsNewClient() { do the stuff... } } when the system will do something like this if(registrySaysThereIs different behavior set for this ServiceObject) { Class toBeCalled = Class.forName("BehaviorOf" + usedServiceObjectName); Object instance = toBeCalled.getConstructor().newInstance(method,client); instance.preExecute(); ....call the service... instance.postExecute(); .... } I am not particularly interested in correctness of code as in correctness of thinking and approach. Actually I have to do this in PHP, witch I see as a kind of Pop music of programming which I have to "sing" for commercial reasons, even though I play POP I really want to sing by the book, so putting aside my more or less inspired analogy I really want to know your opinion on this matter for it's practical necessity and technical approach. Thanks

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  • What's the best way to reference a .DLL - as a normal reference or as a web service?

    - by dotnetdev
    Hi, What is the best way to reference an existing .NET dll (Class library)? Is there any benefit to expose web services from the class library and reference these as opposed to referencing the actual .dll (Although one benefit of the web service approach is the granularity and thus surface area exposed is up to you at coding time)? I am thinking with loose coupling in mind, as a criteria. Thanks

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  • Singleton & Multi-threading

    - by ronan
    Friends I have the following class that class Singleton { private: static Singleton *p_inst; Singleton(); public: static Singleton * instance() { if (!p_inst) { p_inst = new Singleton(); } return p_inst; } }; Please do elaborate on precautions taken while implementing Singleton in multi-threaded environment .. Many thanks

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