Search Results

Search found 67075 results on 2683 pages for 'data model'.

Page 516/2683 | < Previous Page | 512 513 514 515 516 517 518 519 520 521 522 523  | Next Page >

  • Why represent shopping carts and order invoices differently in a domain model?

    - by Todd
    I've built some shopping cart systems in the past, but I always designed them such that the final order invoice is just a shopping cart that has been marked as "purchased". All the logic for adding/removing/changing items in a cart is also the logic for the order. All data is stored in the same tables in the database. But it seems this is not the proper way to design an e-commerce site.. Can someone explain the benefit of separating the shopping cart from invoices in the domain model? It seems to me this would lead to a lot of duplicated code, an extra set of tables in the database, and make it harder to maintain in the event the system need to start accommodating more complicated orders (like specifying selected options for an item which may or may not change the price/availability/shipping time of the order). I'm assuming I just haven't seen the light, as every book and other example I see seems to separate these two seemingly similar concerns -- but I can't find any explanation as to the benefit of doing such! It's also the case in the systems that I design that changes are often made after the initial order is confirmed. It's not uncommon for items to be removed, replaced, or added afterwards (but prior to fulfillment).

    Read the article

  • Does anyone still believe in the Capability Maturity Model for Software?

    - by Ed Guiness
    Ten years ago when I first encountered the CMM for software I was, I suppose like many, struck by how accurately it seemed to describe the chaotic "level one" state of software development in many businesses, particularly with its reference to reliance on heroes. It also seemed to provide realistic guidance for an organisation to progress up the levels improving their processes. But while it seemed to provide a good model and realistic guidance for improvement, I never really witnessed an adherence to CMM having a significant positive impact on any organisation I have worked for, or with. I know of one large software consultancy that claims CMM level 5 - the highest level - when I can see first hand that their processes are as chaotic, and the quality of their software products as varied, as other, non-CMM businesses. So I'm wondering, has anyone seen a real, tangible benefit from adherence to process improvement according to CMM? And if you have seen improvement, do you think that the improvement was specifically attributable to CMM, or would an alternative approach (such as six-sigma) have been equally or more beneficial? Does anyone still believe? As an aside, for those who haven't yet seen it, check out this funny-because-its-true parody

    Read the article

  • Where to translate message strings - in the view or in the model?

    - by GrGr
    We have a multilingual (PHP) application and use gettext for i18n. There are a few classes in the backend/model that return messages or message formats for printf(). We use xgettext to extract the strings that we want to translate. We apply the gettext function T_() in the frontend/view - this seems to be where it belongs. So far we kept the backend clean from T_() calls, this way we can also unit-test messages. So in the frontend we have something like echo T_($mymodel->getMessage()); or printf(T_($mymodel->getMessageFormat()), $mymodel->getValue()); This makes it impossible to apply xgettext to extract the strings, unless we put some dummy T_("my message %s to translate") call in the MyModel class. So this leads to the more general question: Do you apply translation in the backend classes, resp. where do you apply translation and how do you keep track of the strings which you have to translate? (I am aware of Question: poedit workaround for dynamic gettext.)

    Read the article

  • Do the 'up to date' guarantees provided by final field in Java's memory model extend to indirect ref

    - by mattbh
    The Java language spec defines semantics of final fields in section 17.5: The usage model for final fields is a simple one. Set the final fields for an object in that object's constructor. Do not write a reference to the object being constructed in a place where another thread can see it before the object's constructor is finished. If this is followed, then when the object is seen by another thread, that thread will always see the correctly constructed version of that object's final fields. It will also see versions of any object or array referenced by those final fields that are at least as up-to-date as the final fields are. My question is - does the 'up-to-date' guarantee extend to the contents of nested arrays, and nested objects? An example scenario: Thread A constructs a HashMap of ArrayLists, then assigns the HashMap to final field 'myFinal' in an instance of class 'MyClass' Thread B sees a (non-synchronized) reference to the MyClass instance and reads 'myFinal', and accesses and reads the contents of one of the ArrayLists In this scenario, are the members of the ArrayList as seen by Thread B guaranteed to be at least as up to date as they were when MyClass's constructor completed?

    Read the article

  • Rails nested attributes with a join model, where one of the models being joined is a new record

    - by gzuki
    I'm trying to build a grid, in rails, for entering data. It has rows and columns, and rows and columns are joined by cells. In my view, I need for the grid to be able to handle having 'new' rows and columns on the edge, so that if you type in them and then submit, they are automatically generated, and their shared cells are connected to them correctly. I want to be able to do this without JS. Rails nested attributes fail to handle being mapped to both a new record and a new column, they can only do one or the other. The reason is that they are a nested specifically in one of the two models, and whichever one they aren't nested in will have no id (since it doesn't exist yet), and when pushed through accepts_nested_attributes_for on the top level Grid model, they will only be bound to the new object created for whatever they were nested in. How can I handle this? Do I have to override rails handling of nested attributes? My models look like this, btw: class Grid < ActiveRecord::Base has_many :rows has_many :columns has_many :cells, :through => :rows accepts_nested_attributes_for :rows, :allow_destroy => true, :reject_if => lambda {|a| a[:description].blank? } accepts_nested_attributes_for :columns, :allow_destroy => true, :reject_if => lambda {|a| a[:description].blank? } end class Column < ActiveRecord::Base belongs_to :grid has_many :cells, :dependent => :destroy has_many :rows, :through => :grid end class Row < ActiveRecord::Base belongs_to :grid has_many :cells, :dependent => :destroy has_many :columns, :through => :grid accepts_nested_attributes_for :cells end class Cell < ActiveRecord::Base belongs_to :row belongs_to :column has_one :grid, :through => :row end

    Read the article

  • How can I add two models in one form, where one model is a has_many :through?

    - by Angela
    How do I model having multiple Addresses for a Company and assign a single Address to a Contact? Contacts belong_to a Company. A Company has_many Contacts. A Company also has_many Addresses. And each Contact has_one Address. I want to be able, whenever I create a New Contact, to access all the addresses in all Contacts that belong to the Company. Here is are my Models: class Company < ActiveRecord::Base attr_accessible :name, :phone, :addresses has_many :contacts has_many :addresses, :through => :contacts end class Contact < ActiveRecord::Base attr_accessible :first_name, :last_name, :title, :phone, :fax, :email, :company, :date_entered, :campaign_id, :company_name, :address belongs_to :company has_one :address accepts_nested_attributes_for :address end class Address < ActiveRecord::Base attr_accessible :street1 has_many :contacts end How do I create the View in the _form for Contacts so that I can 1) Add an Address when creating a Contact; 2) Display the options of the Address. Here is how I am doing step 1, which is just to add a new address for a new contact: <% f.fields_for :addresses do |builder| %> <p> <%= builder.label :street1, "Street 1" %> </br> <%= builder.text_field :street1 %> <p> Right now, what I have doesn't work. The console says I cannot mass-assign addresses when I hit "submit" on this New contact form.

    Read the article

  • Ruby on Rails How do I access variables of a model inside itself like in this example?

    - by banditKing
    I have a Model like so: # == Schema Information # # Table name: s3_files # # id :integer not null, primary key # owner :string(255) # notes :text # created_at :datetime not null # updated_at :datetime not null # last_accessed_by_user :string(255) # last_accessed_time_stamp :datetime # upload_file_name :string(255) # upload_content_type :string(255) # upload_file_size :integer # upload_updated_at :datetime # class S3File < ActiveRecord::Base #PaperClip methods attr_accessible :upload attr_accessor :owner Paperclip.interpolates :prefix do |attachment, style| I WOULD LIKE TO ACCESS VARIABLE= owner HERE- HOW TO DO THAT? end has_attached_file( :upload, :path => ":prefix/:basename.:extension", :storage => :s3, :s3_credentials => {:access_key_id => "ZXXX", :secret_access_key => "XXX"}, :bucket => "XXX" ) #Used to connect to users through the join table has_many :user_resource_relationships has_many :users, :through => :user_resource_relationships end Im setting this variable in the controller like so: # POST /s3_files # POST /s3_files.json def create @s3_file = S3File.new(params[:s3_file]) @s3_file.owner = current_user.email respond_to do |format| if @s3_file.save format.html { redirect_to @s3_file, notice: 'S3 file was successfully created.' } format.json { render json: @s3_file, status: :created, location: @s3_file } else format.html { render action: "new" } format.json { render json: @s3_file.errors, status: :unprocessable_entity } end end end Thanks, any help would be appreciated.

    Read the article

  • An Array returned by a model association is not an Array?

    - by Warren
    We have a model association that looks something like this: class Example < ActiveRecord::Base has_many :others, :order => 'others.rank' end The rank column is an integer type. The details of these particular models are not really important though as we have found the same problem with other has_many associations between other models. We have also added to the Enumerable module: module Enumerable def method_missing(name) super unless name.to_s[0..7] == 'collect_' method = name.to_s[8..-1] collect{|element| element.send(method)} end end This adds a collect_id method that we can use to get an array of record ids from an array of ActiveRecord objects. So if we use a normal ActiveRecord find :all, we get a nice array which we can then use collect_id on but if we use Example.others.collect_id, we get NoMethodError: undefined method `collect_id' for #<Class:0x2aaaac0060a0> Example.others.class returns "Array" so is it lying or confused? Our solution thus far has been to use it this way: Example.others.to_a.collect_id This works but this seems a bit strange. Why would you have to do that? We are on Ruby 1.8.7 and Rails 2.3.4

    Read the article

  • byte and short data types in Java can accept the value outside the range by explicit cast. The higher data types however can not. Why?

    - by Lion
    Let's consider the following expressions in Java. byte a = 32; byte b = (byte) 250; int i = a + b; This is valid in Java even though the expression byte b = (byte) 250; is forced to assign the value 250 to b which is outside the range of the type byte. Therefore, b is assigned -6 and consequently i is assigned the value 26 through the statement int i = a + b;. The same thing is possible with short as follows. short s1=(short) 567889999; Although the specified value is outside the range of short, this statement is legal. The same thing is however wrong with higher data types such int, double, folat etc and hence, the following case is invalid and causes a compile-time error. int z=2147483648; This is illegal, since the range of int in Java is from -2,147,483,648 to 2147483647 which the above statement exceeds and issues a compile-time error. Why is such not wrong with byte and short data types in Java?

    Read the article

  • wondering how much data bandwidth can a 3G gsm cell tower can support?

    - by Karim
    i was always wondering how many simaltinues users can a 3G tower supports with its data rates? i mean they advertize 28.8Mb/Sec for the 3G Data but in reallity if a lot of people use it say 10 , it wont give 288Mb/Sec bandwidth. i didnt find anywhere where such information is published so i thought to ask here. dont know why the cell operators keep it such a secret :)

    Read the article

  • How much data bandwidth can a 3G gsm cell tower can support?

    - by Karim
    I was always wondering how many simultaneous users can a 3G tower supports with its data rates? I mean they advertise 28.8Mb/Sec for the 3G Data but in reality if a lot of people use it say 10 , it wont give 288Mb/Sec bandwidth. I didn't find anywhere where such information is published so I thought to ask here. Don' know why the cell operators keep it such a secret :)

    Read the article

  • How can I sort my data while keeping paired rows together?

    - by Joe Lee Frank
    How can I pair two rows on a spreadsheet, so that for each data entry I can sort the matrix but the pair of rows moves as a single list of data, retaining the structure of the two rows? For example: Original entry A1,1 B1,1 C1,1 D1,1 A1,2 B1,2 C1,2 D1,2 A2,1 B2,1 C2,1 D2,1 A2,2 B2,2 C2,2 D2,2 Sorted reverse order A2,1 B2,1 C2,1 D2,1 A2,2 B2,2 C2,2 D2,2 A1,1 B1,1 C1,1 D1,1 A1,2 B1,2 C1,2 D1,2

    Read the article

  • How could I import Postgres data dumps into MS SQL?

    - by dean nolan
    I have some data that is from a Postgres database dump (not csv or anything) and I am looking to get it into MS SQL. Is there an easy way to do this or a free tool that doesn't have limits on data import size etc? The Postgres is on a Debian VM and I could export it to csv in there but I am new to Linux and don't know how I would transfer it from the VM to Win 7. Thanks

    Read the article

  • How can I find a laptop if it has a different model name all over the world?

    - by Mike
    CONUNDRUM: A laptop review in the UK talks about how brilliant the "ASUS ABCDE 55" is, but in America, France, etc there is no such laptop name. In fact it's called "ASUS 12345 AB" - AAARRGH! QUESTION: Is there a way of finding out all the diverse names for the same laptop all over the world? Example: if Samsung create a R2D2500, then what is that spec laptop called in all the other countries (if they release it of course). Or if it's not released, what is their similar spec laptop called in the other countries? I understand that specs may be different, but if I read a review on my trusted UK website, but live in say Australia, I want to be able to find the name of the same laptop in Australia and then check out local places to buy it. So if anyone knows if there is a technique, specific website, or even how to use a company website to find out these annoying name changes I'd really appreciate it.

    Read the article

  • HDD,CD,DVD - how is sector id distinguishable from data?

    - by b-gen-jack-o-neill
    Hi, as titles says, how is sector id on HDD,CD-ROM and so distinguishable from data? I mean, when I want lets say sector #52, first, head goes to track where this sector should be, than it must wait some time to spin the desired sector above the reading head. But it must somehow recognize that its sector number, and not only data that say 52. So, how is this done? Thanks.

    Read the article

  • Why does cifs asks for su rights to write any data into it?

    - by Denys S.
    I'm mounting a windows share as follows: sudo mount -t cifs //192.168.178.49/public -o users,username=name,dom=domain,password=pword /mnt/nas Then I'm trying to create a simple file with some basic text: touch /mnt/nas/me.txt And get an error, however, the file is created (contains 0B of data though): touch: cannot touch ‘me.txt’: Permission denied With sudo it works flawless. How can I allow my current user to write data to the share? Is there a mount option?

    Read the article

  • Exchange IMAP4 connector - Error Event ID 2006

    - by MikeB
    Hi, A couple of users in my organisation use IMAP4 to connect to Exchange 2007 (Update rollup 9 applied) because they prefer Thunderbird / Postbox clients. One of the users is generating errors in the Application Log as follows: An exception Microsoft.Exchange.Data.Storage.ConversionFailedException occurred while converting message Imap4Message 1523, user "*******", folder *********, subject: "******", date: "*******" into MIME format. Microsoft.Exchange.Data.Storage.ConversionFailedException: Message content has become corrupted. ---> System.ArgumentException: Value should be a valid content type in the form 'token/token' Parameter name: value at Microsoft.Exchange.Data.Mime.ContentTypeHeader.set_Value(String value) at Microsoft.Exchange.Data.Storage.MimeStreamWriter.WriteHeader(HeaderId type, String data) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimeStreamAttachment(StreamAttachmentBase attachment, MimeFlags flags) --- End of inner exception stack trace --- at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimeStreamAttachment(StreamAttachmentBase attachment, MimeFlags flags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimeAttachment(MimePartInfo part, MimeFlags flags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimePart(MimePartInfo part, MimeFlags mimeFlags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimeParts(List`1 parts, MimeFlags mimeFlags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimePart(MimePartInfo part, MimeFlags mimeFlags) at Microsoft.Exchange.Data.Storage.ImapItemConverter.<>c__DisplayClass2.<WriteMimePart>b__0() at Microsoft.Exchange.Data.Storage.ConvertUtils.CallCts(Trace tracer, String methodName, String exceptionString, CtsCall ctsCall) at Microsoft.Exchange.Data.Storage.ImapItemConverter.WriteMimePart(ItemToMimeConverter converter, MimeStreamWriter writer, OutboundConversionOptions options, MimePartInfo partInfo, MimeFlags conversionFlags) at Microsoft.Exchange.Data.Storage.ImapItemConverter.GetBody(Stream outStream) at Microsoft.Exchange.Data.Storage.ImapItemConverter.GetBody(Stream outStream, UInt32[] indices) From my reading around it seems that the suggestion is to ask users to log in to Outlook / OWA and view the messages there. However, having logged in as the users myself, the messages cannot be found either through searching or by browsing the folder detailed in the log entry. The server returns the following error to the client: "The message could not be retrieved using the IMAP4 protocol. The message has not been deleted and may be accessible using either Microsoft Outlook or Microsoft Office Outlook Web Access. You can also try contacting the original sender of the message to find out about the contents of the message. Retrieval of this message will be retried when the server is updated with a fix that addresses the problem." Messages were transferred in to Exchange by copying them from the old Apple Xserve, accessed using IMAP. So my question, finally: 1. Is there any way to get the IMAP Exchange connector to rebuild its cache of messages since it doesn't seem to be pulling them directly from the MAPI store? 2. Alternatively, if there is no database, any ideas on why these messages don't appear in Outlook or OWA would be gratefully received. Many thanks, Mike

    Read the article

  • Is there a CPU that can be described as "Celeron D 4xx model"?

    - by romkyns
    The "D" letter after Celeron appears to only be used for processors numbered with 3xx. Celerons of the 4xx series do not seem to have the "D". And yet I am looking at a motherboard described as supporting these processors: Intel Celeron D 3xx and 4xx models Intel Pentium 4 5xx and 6xx models Intel Pentium D 8xx and 9xx models Intel Core 2 Duo models with LGA775 Is this compatible with a Celeron 450, sSpec SLAFZ, despite not having a "D" in its name?

    Read the article

  • How do I restore a partition without losing the data?

    - by sama
    I lost the D-partition in My Computer I opened My Computer, but couldn't find it and I don't know where it is or how to return it. I went to Disk Management and found it available as free space. So I tried to make it NTFS, but I had to format the drive and I don't want to, since it will erase my data. Does anyone know how I can restore my partition without losing my data?

    Read the article

  • What is the best way to secure MySQL data on a laptop *without* whole-disk-encryption?

    - by GJ
    I need to have the mysql data on my laptop stored in an encrypted state so that in case of the laptop being lost/stolen it will extremely difficult to recover the data without the password. I don't wish to use whole disk encryption, due to the performance impact it will have on other disk-intensive programs' usage. What could be the ideal solution for me balancing security and performance? Thanks!

    Read the article

< Previous Page | 512 513 514 515 516 517 518 519 520 521 522 523  | Next Page >