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  • Devise routes /:param not working

    - by Jacob Schatz
    Using devise 2.1.0 I am trying to send the new registration page a PricingPlan model. So in my routes I have: devise_scope :user do delete "/logout" => "devise/sessions#destroy" get "/login" => "devise/sessions#new" get "/signup/:plan" => "devise/registrations#new" end And I override the devise registration controller. With this in my routes.rb to make it work: devise_for :users, :controllers => {:registrations => "registrations"} In my actual Registration controller which overrides Devise's controller I have: class RegistrationsController < Devise::RegistrationsController view_paths = "app/views/devise" def new super @plan = PricingPlan.find_by_name(params[:plan]) end So that the default views still go to devise.... In my new view for the registration controller I call this: <h3>You've chosen the <%= @plan.name %> plan.</h3> And I get this error: undefined method `name' for nil:NilClass Also... in my PricingPlan model: class PricingPlan < ActiveRecord::Base has_many :users And in my User model: class User < ActiveRecord::Base belongs_to :pricing_plan I'm rather new at rails.

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  • ASP.NET MVC PartialView generic ModelView

    - by Greg Ogle
    I have an ASP.NET MVC application which I want to dynamically pick the partial view and what data gets passed to it, while maintaining strong types. So, in the main form, I want a class that has a view model that contains a generically typed property which should contain the data for the partial view's view model. public class MainViewModel<T> { public T PartialViewsViewModel { get; set; } } In the User Control, I would like something like: Inherits="System.Web.Mvc.ViewUserControl<MainViewModel<ParticularViewModel>>" %> Though in my parent form, I must put Inherits="System.Web.Mvc.ViewPage<MainViewModel<ParticularViewModel>>" %> for it to work. Is there a way to work around this? The use case is to make the user control pluggable. I understand that I could inherit a base class, but that would put me back to having something like a dictionary instead of a typed view model.

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  • Multithreading and Interrupts

    - by Nicholas Flynt
    I'm doing some work on the input buffers for my kernel, and I had some questions. On Dual Core machines, I know that more than one "process" can be running simultaneously. What I don't know is how the OS and the individual programs work to protect collisions in data. There are two things I'd like to know on this topic: (1) Where do interrupts occur? Are they guaranteed to occur on one core and not the other, and could this be used to make sure that real-time operations on one core were not interrupted by, say, file IO which could be handled on the other core? (I'd logically assume that the interrupts would happen on the 1st core, but is that always true, and how would you tell? Or perhaps does each core have its own settings for interrupts? Wouldn't that lead to a scenario where each core could react simultaneously to the same interrupt, possibly in different ways?) (2) How does the dual core processor handle opcode memory collision? If one core is reading an address in memory at exactly the same time that another core is writing to that same address in memory, what happens? Is an exception thrown, or is a value read? (I'd assume the write would work either way.) If a value is read, is it guaranteed to be either the old or new value at the time of the collision? I understand that programs should ideally be written to avoid these kinds of complications, but the OS certainly can't expect that, and will need to be able to handle such events without choking on itself.

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  • Delphi, PGDac vs Zeos, Fetch, Lookup?

    - by durumdara
    Hi! I used Zeos to test to know: is ZTable uses fetch technics, or not? May in the future we migrate our lesser system to PGSQL, and this used now "Table" components (as BDE, but it have an SQL-like server). These tables use real cursors, a "Window" with N record, so lookup is very fast, because the Locate/Lookup is started on server, and only these N records are refreshed, no matter, how many records in the lookup table. PGSQL uses fetch technics as I know, and I tested it with a table (id int, name varchar(100)), and 1 million records. (I also trying this with mysql). The adapter is Zeos. ID, sec to find, allocated memory in bytes on client. MySQL 500000 2,761 113 196 344 1000000 3,214 225 471 232 313800 0,437 225 471 232 328066 0,468 225 471 232 276374 0,390 225 471 232 905984 1,264 225 471 232 260253 0,359 225 471 232 PGSQL 500000 3,042 113 188 184 1000000 3,744 225 463 064 313800 0,436 225 463 064 328066 0,452 225 463 064 276374 0,375 225 463 064 905984 1,295 225 463 064 260253 0,359 225 463 064 142023 0,203 225 463 064 As you see the records are fetched locally, this cause the 225 MB usage, and searches are slow a little, based where is the record we must find. I want to ask more things: a.) Is PGDAC have some technics to we can use the lookups without pay the fetch with memory and secs? b.) Or is PG ODBC driver can help in this problem with ADO? (As I know ADO can use server side cursors)? c.) Have anybody some experience with lookup tables, and performance? Is this critical question or it is not? (With client memory usage too). d.) If no chance to avoid fetch hell with lookups, what we can do? Server Side Joins, and unique code for Lookup field changing without real Lookup? Thanks for your help: dd

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  • Django ModelForm is giving me a validation error that doesn't make sense

    - by River Tam
    I've got a ModelForm based on a Picture. class Picture(models.Model): name = models.CharField(max_length=100) pub_date = models.DateTimeField('date published') tags = models.ManyToManyField('Tag', blank=True) content = models.ImageField(upload_to='instaton') def __unicode__(self): return self.name class PictureForm(forms.ModelForm): class Meta: model = Picture exclude = ('pub_date','tags') That's the model and the ModelForm, of course. def submit(request): if request.method == 'POST': # if the form has been submitted form = PictureForm(request.POST) if form.is_valid(): return HttpResponseRedirect('/django/instaton') else: form = PictureForm() # blank form return render_to_response('instaton/submit.html', {'form': form}, context_instance=RequestContext(request)) That's the view (which is being correctly linked to by urls.py) Right now, I do nothing when the form submits. I just check to make sure it's valid. If it is, I forward to the main page of the app. <form action="/django/instaton/submit/" method="post"> {% csrf_token %} {{ form.as_p }} <input type="submit" value"Submit" /> </form> And there's my template (in the correct location). When I try to actually fill out the form and just validate it, even if I do so correctly, it sends me back to the form and says "This field is required" between Name and Content. I assume it's referring to Content, but I'm not sure. What's my problem? Is there a better way to do this?

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  • Most efficient way to send images across processes

    - by Heinrich Ulbricht
    Goal Pass images generated by one process efficiently and at very high speed to another process. The two processes run on the same machine and on the same desktop. The operating system may be WinXP, Vista and Win7. Detailled description The first process is solely for controlling the communication with a device which produces the images. These images are about 500x300px in size and may be updated up to several hundred times per second. The second process needs these images to display them. The first process uses a third party API to paint the images from the device to a HDC. This HDC has to be provided by me. Note: There is already a connection open between the two processes. They are communicating via anonymous pipes and share memory mapped file views. Thoughts How would I achieve this goal with as little work as possible? And I mean both work for me and the computer. I am using Delphi, so maybe there is some component available for doing this? I think I could always paint to any image component's HDC, save the content to memory stream, copy the contents via the memory mapped file, unpack it on the other side and paint it there to the destination HDC. I also read about a IPicture interface which can be used to marshall images. What are your ideas? I appreciate every thought on this!

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  • Maintaining state and data context between requests in ASP.NET + EF4

    - by Nick
    I have a EF4/ASP.NET web application that is structured to use POCOs and generic repositories, based essentially on this excellent article. The application is relatively sophisticated with one page that involves selection and linking of multiple entities to build up a complex user profile. This requires access to multiple entity types (20 or so) and associated repositories across multiple posts. When a repository is first accessed it uses the existing data context if exists, else it creates a new context. The problem is that if the lifetime of the context is only per-request (as suggested in the article) then you have to deal with multiple contexts and the complexity around detaching and attaching entities from contexts. My solution is to share the context between posts by creating a single View Model that includes all required repositories (initialised to share the same context) plus any associated data and store this model in a Session variable, retrieving from Session on subsequent page requests. Therefore maintaining the same context across all posts until the profile is saved. This works fine BUT I am concerned that I don't actually know exactly what is stored in the model session variable or more importantly the size of the Session variable. So two questions I suppose: firstly should I look for a better solution to handle the shared context across posts issue (any suggestions welcome)? And secondly what is actually stored in the Session when it includes a repository plus context? Any help appreciated!

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  • Is there a problem with this MySQL Query?

    - by ThinkingInBits
    http://pastie.org/954073 The echos at the top all display valid data that fit the database schema. There are no connection errors Any ideas? Thanks in advance! Here is the echo'ed query INSERT INTO equipment (cat_id, name, year, manufacturer, model, price, location, condition, stock_num, information, description, created, modified) VALUES (1, 'r', 1, 'sdf', 'sdf', '2', 'd', 'd', '3', 'asdfasdfdf', 'df', '10 May 10', '10 May 10') MySQL is giving: #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'condition, stock_num, information, description, created, modified) VALUES (1, 'r' at line 1 id int(11) unsigned NO PRI NULL auto_increment Edit Delete cat_id int(11) unsigned NO NULL Edit Delete prod_name varchar(255) YES NULL Edit Delete prod_year varchar(10) YES NULL Edit Delete manufacturer varchar(255) YES NULL Edit Delete model varchar(255) YES NULL Edit Delete price varchar(10) YES NULL Edit Delete location varchar(255) YES NULL Edit Delete condition varchar(25) YES NULL Edit Delete stock_num varchar(128) YES NULL Edit Delete information text YES NULL Edit Delete description text YES NULL Edit Delete created varchar(20) YES NULL Edit Delete modified varchar(20) YES NULL Query: INSERT INTO equipment (cat_id, prod_name, prod_year, manufacturer, model, price, location, condition, stock_num, information, description, created, modified) VALUES (1, 'asdf', '234', 'adf', 'asdf', '34', 'asdf', 'asdf', '234', 'asdf', 'asdf', '10 May 10', '10 May 10')

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  • The Select query I am using is not working.. Can Somebody Guide me to the Correct way?

    - by Parth
    I am using the Select query as SELECT id, ordering FROM `jos_menu` WHERE ordering='".$rec['ordering'] -'1' ."' AND parent = '0' Here I need all the records whose ordering is less than 1 of the selected record's order($rec['ordering'] = getting from other select query ) when I am trying to echo the query I am not getting complete statement but getting only this -1' AND parent = '0' here is the whole snippet $where = ' WHERE (id = ' . implode( ' OR id = ', $cid ) . ')';//Pranav Dave Coded echo $selquery = "SELECT id, ordering FROM `jos_menu`".$where; //Pranav Dave Coded $db->setQuery( $selquery );//Pranav Dave Coded $record = $db->loadAssocList(); //Pranav Dave Coded if ($model->orderItem($id, -1)) { echo "<pre>"; print_r($model); /*exit;*/ //echo $updorderup = mysql_escape_string($model->_db->_sql);//Pranav Dave Coded foreach($record as $rec)//Pranav Dave Coded { echo $aboverow = "SELECT id, ordering FROM `jos_menu` WHERE ordering='".$rec['ordering'] -'1' ."' AND parent = '0'"; $db->setQuery( $aboverow ); $above = $db->loadAssoc(); echo "<pre>"; print_r($above); }//end of foreach }//end of if Please suggest me where I am getting wrong.....

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  • Ibator didn't generate Oracle varchar2 field

    - by bugbug
    I have table APP_REQ_APPROVE_COMPARE with following fields: "ID" NUMBER NOT NULL ENABLE, "TRACK_NO" VARCHAR2(20 BYTE) NOT NULL ENABLE, "REQ_DATE" DATE NOT NULL ENABLE, "OFFCODE" CHAR(6 BYTE) NOT NULL ENABLE, "COMPARE_CASE_ID" NUMBER NOT NULL ENABLE, "VEHICLE_NAME" VARCHAR2(100 BYTE), "ENGINE_NO" VARCHAR2(100 BYTE), "BODY_NO" VARCHAR2(100 BYTE), "HOLD_SHIP" NUMBER, "OWNERSHIP" VARCHAR2(200 BYTE), "RENT_NAME" VARCHAR2(200 BYTE), "CONTRACT" VARCHAR2(100 BYTE), "CONTRACT_NO" VARCHAR2(100 BYTE), "CONTRACT_DATE" DATE, "ISLAWBREAKERRENT" CHAR(1 BYTE) NOT NULL ENABLE, "MISTAKE_DETAIL" VARCHAR2(4000 BYTE), "COMPARE_REASON" VARCHAR2(4000 BYTE), "CREATE_BY" NUMBER NOT NULL ENABLE, "CREATE_ON" DATE DEFAULT SYSDATE NOT NULL ENABLE, "UPDATE_BY" NUMBER, "UPDATE_ON" DATE, When I generate a java bean using Ibator , I didn't find trackNo, VehicalName, ... (all fields defined as varchar2). What is the problem in my case? Here is my Ibator configuration file: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE ibatorConfiguration PUBLIC "-//Apache Software Foundation//DTD Apache iBATIS Ibator Configuration 1.0//EN" "http://ibatis.apache.org/dtd/ibator-config_1_0.dtd"> <ibatorConfiguration> <classPathEntry location="/dos/connector/oracle_jdbc.jar"/> <ibatorContext id="autoPerson" defaultModelType="flat" targetRuntime="Ibatis2Java2"> <jdbcConnection connectionURL="jdbc:oracle:thin:@192.168.42.144:1521:orcl" driverClass="oracle.jdbc.driver.OracleDriver" userId="user" password="password"/> <javaModelGenerator targetPackage="com.ko.model" targetProject="FormConfig"> <property name="enableSubPackages" value="true"/> <property name="trimStrings" value="true"/> </javaModelGenerator> <sqlMapGenerator targetPackage="com.ko.map" targetProject="FormConfig"> <property name="enableSubPackages" value="true"/> </sqlMapGenerator> <daoGenerator targetPackage="com.ko.model.dao" type="SPRING" targetProject="FormConfig" implementationPackage="com.ko.model.dao.impl" > <property name="enableSubPackges" value="true"/> <property name="methodNameCalculator" value="extended"/> </daoGenerator> <table tableName="APP_REQ_APPROVE_COMPARE" domainObjectName="AppReqApproveCompare"/> <ibatorConfiguration>

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  • Boost::Mutex & Malloc

    - by M. Tibbits
    Hi all, I'm trying to use a faster memory allocator in C++. I can't use Hoard due to licensing / cost. I was using NEDMalloc in a single threaded setting and got excellent performance, but I'm wondering if I should switch to something else -- as I understand things, NEDMalloc is just a replacement for C-based malloc() & free(), not the C++-based new & delete operators (which I use extensively). The problem is that I now need to be thread-safe, so I'm trying to malloc an object which is reference counted (to prevent excess copying), but which also contains a mutex pointer. That way, if you're about to delete the last copy, you first need to lock the pointer, then free the object, and lastly unlock & free the mutex. However, using malloc to create a boost::mutex appears impossible because I can't initialize the private object as calling the constructor directly ist verboten. So I'm left with this odd situation, where I'm using new to allocate the lock and nedmalloc to allocate everything else. But when I allocate a large amount of memory, I run into allocation errors (which disappear when I switch to malloc instead of nedmalloc ~ but the performance is terrible). My guess is that this is due to fragmentation in the memory and an inability of nedmalloc and new to place nice side by side. There has to be a better solution. What would you suggest?

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  • GWT serialization issue

    - by Eddy
    I am having a heck of a time returning an ArrayList of objects that implement IsSerializable via RPC. The IsSerializable pojo contains one variable, a String, and has a 0 parameter constructor. I have removed the .gwt.rpc file from my war and still I get: com.google.gwt.user.client.rpc.SerializationException: Type 'com.test.myApp.client.model.Test' was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.: instance = com.test.myApp.client.model.Test@17a9692 at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:610) I am using GWT 2.0.2 with jdk 1.6.0_18. Any ideas on what might be going on or what I am doing wrong? Here is the code for the Test class and the remote method is returning ArrayList. I even modified the code for it to just return one instance of Test with the same result: the exception above. package com.test.myApp.client.model; import com.google.gwt.user.client.rpc.IsSerializable; public class Test implements IsSerializable{ private String s; public Test() {} public Test(String s) { this.s = s; } public String getS() { return s; } public void setS(String s) { this.s = s; } } Greatly appreciate the help! Eddy

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  • How do I relate tables with different foreign key names in Kohana ORM?

    - by Matt H
    I'm building a Kohaha application to manage sip lines in asterisk. I'm wanting to use ORM but I'm wondering how do relate certain tables that are already well established. e.g. the table sip_lines looks like this. +--------------------+------------------+------+-----+-------------------+-----------------------------+ | Field | Type | Null | Key | Default | Extra | +--------------------+------------------+------+-----+-------------------+-----------------------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | sip_name | varchar(80) | NO | UNI | NULL | | | displayname | varchar(48) | NO | | NULL | | | line_num | varchar(10) | NO | MUL | NULL | | | model | varchar(12) | NO | MUL | NULL | | | mac | varchar(16) | NO | MUL | NULL | | | areacode | varchar(6) | NO | MUL | NULL | | | per_line_astpp_acc | tinyint(1) | NO | | 0 | | | play_warning | tinyint(1) | NO | | 0 | | | callout_disabled | tinyint(1) | NO | | 0 | | | notes | varchar(80) | NO | | NULL | | | last_update | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP | +--------------------+------------------+------+-----+-------------------+-----------------------------+ sip_buddies is this: +----------------+------------------------------+------+-----+-----------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------------+------------------------------+------+-----+-----------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | name | varchar(80) | NO | UNI | | | | host | varchar(31) | NO | | | | | | | lastms | int(11) | NO | | 0 *** snip *** +----------------+------------------------------+------+-----+-----------+----------------+ The two tables are actually related as sip_lines.sip_name = sip_buddies.name How do I relate them in Kohana ORM as this wouldn't be quite right would it? <?php defined('SYSPATH') or die('No direct script access.'); /* A model for all the account information */ class Sip_Line_Model extends ORM { protected $has_one = array("sip_buddies"); } ?> EDIT: Actually, it'd be fair to say that these tables are not properly related with foreign keys! doh. EDIT: Looks like Kohana ORM is not that flexible. ORM is probably not the way to go and works best for completely new projects where the data model can be altered. The reason being that the key names must follow a specific naming convention or else they won't relate in Kohana.

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  • Using Zend Framework and Doctrine with independend modular structures

    - by stefax
    I've seen a lot of articles about integrating ZF and Doctrine. There is also a proposal for ZF here but they have always two possible structures. Either they put all models into one top level model directory or they put it into a module related model directory. application |-- Bootstrap.php |-- configs |-- controllers |-- models - EITHER HERE |-- modules | -- examplemodule | |-- controllers | |-- models - OR HERE | |-- views |-- views For our projects I see problems for either of the two options: 1. One directory: application/models - in a complex system after a short time there will be hundreds of files, over all when you have the table classes two (e.g. User.php and UserTable.php). 2. Module based model directories: application/modules/examplemodule/models - in many cases we use models in multiple modules at the same time. So the "User" is required e.g. in the modules "game", "administration", ... Is there a way to use some kind of sub directories under the top level directory "models" to get some grouping. It should be completely independent of the module structure. application |-- Bootstrap.php ... |-- models | -- user | |-- User.php | |-- Friend.php | |-- other user related models | -- game | |-- Game.php | |-- Score.php | |-- ... ... Any solution should support autoloading and the class generation from yaml files. Any ideas, links or solutions? Thanks!

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  • How make this special many2many fields validation using Django ORM?

    - by e-satis
    I have the folowing model: class Step(models.Model): order = models.IntegerField() latitude = models.FloatField() longitude = models.FloatField() date = DateField(blank=True, null=True) class Journey(models.Model): boat = models.ForeignKey(Boat) route = models.ManyToManyField(Step) departure = models.ForeignKey(Step, related_name="departure_of", null=True) arrival = models.ForeignKey(Step, related_name="arrival_of", null=True) I would like to implement the following check: # If a there is less than one step, raises ValidationError. routes = tuple(self.route.order_by("date")) if len(routes) <= 1: raise ValidationError("There must be at least two setps in the route") # save the first and the last step as departure and arrival self.departure = routes[0] self.arrival = routes[-1] # departure and arrival must at least have a date if not (self.departure.date or self.arrival.date): raise ValidationError("There must be an departure and an arrival date. " "Please set the date field for the first and last Step of the Journey") # departure must occurs before arrival if not (self.departure.date > self.arrival.date): raise ValidationError("Departure must take place the same day or any date before arrival. " "Please set accordingly the date field for the first and last Step of the Journey") I tried to do that by overloading save(). Unfortunately, Journey.route is empty in save(). What's more, Journey.id doesn't exists yet. I didn't try django.db.models.signals.post_save but suppose it will fail because Journey.route is empty as well (when does this get filled anyway?). I see a solution in django.db.models.signals.m2m_changed but there are a lot of steps (thousands), and I want to avoid to perform an operation for every single of them.

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  • Android:Playing bigger size audio wav sound file produces crash

    - by user187532
    Hi Android experts, I am trying to play the bigger size audio wav file(which is 20 mb) using the following code(AudioTrack) on my Android 1.6 HTC device which basically has less memory. But i found device crash as soon as it executes reading, writing and play. But the same code works fine and plays the lesser size audio wav files(10kb, 20 kb files etc) very well. P.S: I should play PCM(.wav) buffer sound, the reason behind why i use AudioTrack here. Though my device has lesser memory, how would i read bigger audio files bytes by bytes and play the sound to avoid crashing due to memory constraints. private void AudioTrackPlayPCM() throws IOException { String filePath = "/sdcard/myWav.wav"; // 8 kb file byte[] byteData = null; File file = null; file = new File(filePath); byteData = new byte[(int) file.length()]; FileInputStream in = null; try { in = new FileInputStream( file ); in.read( byteData ); in.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } int intSize = android.media.AudioTrack.getMinBufferSize(8000, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_8BIT); AudioTrack at = new AudioTrack(AudioManager.STREAM_MUSIC, 8000, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_8BIT, intSize, AudioTrack.MODE_STREAM); at.play(); at.write(byteData, 0, byteData.length); at.stop(); at.release(); } Could someone guide me please to play the AudioTrack code for bigger size wav files?

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  • Rails help looping trough has one and belongs to association

    - by Rails beginner
    This is my kategori controller show action: def show @kategori = Kategori.find(params[:id]) @konkurrancer = @kategori.konkurrancer respond_to do |format| format.html # show.html.erb format.xml { render :xml => @kategori } end end This is kategori view show file: <% @konkurrancer.each do |vind| %> <td><%= vind.name %></td> <td>4 ud af 5</td> <td><%= number_to_currency(vind.vaerdi, :unit => "DKK", :separator => ".", :delimiter => ".", :format => "%n %u", :precision => 0) %></td> <td>2 min</td> <td>Nyhedsbrev</td> <td><%= vind.udtraekkes.strftime("%d %B") %></td> </tr> <% end %> My kategori model: class Kategori < ActiveRecord::Base has_one :konkurrancer end My konkurrancer model: class Konkurrancer < ActiveRecord::Base belongs_to :kategori end I want show all of the konkurrancer that have an association to the kategori model With my code I get the following error: NoMethodError in Kategoris#show Showing C:/Rails/konkurranceportalen/app/views/kategoris/show.html.erb where line #12 raised: undefined method `each' for "#":Konkurrancer

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  • Is it approproate it use django signals withing the same app

    - by Alex Lebedev
    Trying to add email notification to my app in the cleanest way possible. When certain fields of a model change, app should send a notification to a user. Here's my old solution: from django.contrib.auth import User class MyModel(models.Model): user = models.ForeignKey(User) field_a = models.CharField() field_b = models.CharField() def save(self, *args, **kwargs): old = self.__class__.objects.get(pk=self.pk) if self.pk else None super(MyModel, self).save(*args, **kwargs) if old and old.field_b != self.field_b: self.notify("b-changed") # Sevelar more events here # ... def notify(self, event) subj, text = self._prepare_notification(event) send_mail(subj, body, settings.DEFAULT_FROM_EMAIL, [self.user.email], fail_silently=True) This worked fine while I had one or two notification types, but after that just felt wrong to have so much code in my save() method. So, I changed code to signal-based: from django.db.models import signals def remember_old(sender, instance, **kwargs): """pre_save hanlder to save clean copy of original record into `old` attribute """ instance.old = None if instance.pk: try: instance.old = sender.objects.get(pk=instance.pk) except ObjectDoesNotExist: pass def on_mymodel_save(sender, instance, created, **kwargs): old = instance.old if old and old.field_b != instance.field_b: self.notify("b-changed") # Sevelar more events here # ... signals.pre_save.connect(remember_old, sender=MyModel, dispatch_uid="mymodel-remember-old") signals.post_save.connect(on_mymodel_save, sender=MyModel, dispatch_uid="mymodel-on-save") The benefit is that I can separate event handlers into different module, reducing size of models.py and I can enable/disable them individually. The downside is that this solution is more code and signal handlers are separated from model itself and unknowing reader can miss them altogether. So, colleagues, do you think it's worth it?

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  • Boost causes an invalid block while overloading new/delete operators

    - by user555746
    Hi, I have a problem which appears to a be an invalid memory block that happens during a Boost call to Boost:runtime:cla::parser::~parser. When that global delete is called on that object, C++ asserts on the memory block as an invalid: dbgdel.cpp(52): /* verify block type */ _ASSERTE(_BLOCK_TYPE_IS_VALID(pHead->nBlockUse)); An investigation I did revealed that the problem happened because of a global overloading of the new/delete operators. Those overloadings are placed in a separate DLL. I discovered that the problem happens only when that DLL is compiled in RELEASE while the main application is compiled in DEBUG. So I thought that the Release/Debug build flavors might have created a problem like this in Boost/CRT when overloading new/delete operators. So I then tried to explicitly call to _malloc_dbg and _free_dbg withing the overloading functions even in release mode, but it didn't solve the invalid heap block problem. Any idea what the root cause of the problem is? is that situation solvable? I should stress that the problem began only when I started to use Boost. Before that CRT never complained about any invalid memory block. So could it be an internal Boost bug? Thanks!

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  • rails HABTM versus view (formtastic)

    - by VP
    I have two models: The model NetworkObject try to describe "hosts". I want to have a rule with source and destination, so i'm trying to use both objects from the same class since it dont makes sense to create two different classes. class NetworkObject < ActiveRecord::Base attr_accessible :ip, :netmask, :name has_many :statements has_many :rules, :through =>:statements end class Rule < ActiveRecord::Base attr_accessible :active, :destination_ids, :source_ids has_many :statements has_many :sources, :through=> :statements, :source=> :network_object has_many :destinations, :through => :statements, :source=> :network_object end To build the HABTM i did choose the Model JOIN. so in this case i created a model named Statement with: class Statement < ActiveRecord::Base attr_accessible :source_id, :rule_id, :destination_id belongs_to :network_object, :foreign_key => :source_id belongs_to :network_object, :foreign_key => :destination_id belongs_to :rule end The problem is: is right to add two belongs_to to the same class using different foreign_keys? I tried all combinations like: belongs_to :sources, :class_name => :network_object, :foreign_key => :source_id but no success.. anything that i am doing wrong?

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  • Adding custom methods to a subclassed NSManagedObject

    - by CJ
    I have a Core Data model where I have an entity A, which is an abstract. Entities B, C, and D inherit from entity A. There are several properties defined in entity A which are used by B, C, and D. I would like to leverage this inheritance in my model code. In addition to properties, I am wondering if I can add methods to entity A, which are implemented in it's sub-entities. For example: I add a method to the interface for entity A which returns a value and takes one argument I add implementations of this method to A, B, C, D Then, I call executeFetchRequest: to retrieve all instances of B I call the method on the objects retrieved, which should call the implementation of the method contained in B's implementation I have tried this, but when calling the method, I receive: [NSManagedObject methodName:]: unrecognized selector sent to instance I presume this is because the objects returned by executeFetchRequest: are proxy objects of some sort. Is there any way to leverage inheritance using subclassed NSManagedObjects? I would really like to be able to do this, otherwise my model code would be responsible for determining what type of NSManagedObject it's dealing with and perform special logic according to the type, which is undesirable. Any help is appreciated, thanks in advance.

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  • global variables in php not working as expected

    - by Josh Smeaton
    I'm having trouble with global variables in php. I have a $screen var set in one file, which requires another file that calls an initSession() defined in yet another file. The initSession() declares "global $screen" and then processes $screen further down using the value set in the very first script. How is this possible? To make things more confusing, if you try to set $screen again then call the initSession(), it uses the value first used once again. The following code will describe the process. Could someone have a go at explaining this? $screen = "list1.inc"; // From model.php require "controller.php"; // From model.php initSession(); // From controller.php global $screen; // From Include.Session.inc echo $screen; // prints "list1.inc" // From anywhere $screen = "delete1.inc"; // From model2.php require "controller2.php" initSession(); global $screen; echo $screen; // prints "list1.inc" Update: If I declare $screen global again just before requiring the second model, $screen is updated properly for the initSession() method. Strange.

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  • IntegrityError: foreign key violation upon delete

    - by Lukasz Korzybski
    I have Order and Shipment model. Shipment has a foreign key to Order. class Order(...): ... class Shipment() order = m.ForeignKey('Order') ... Now in one of my views I want do delete order object along with all related objects. So I invoke order.delete(). I have Django 1.0.4, PostgreSQL 8.4 and I use transaction middleware, so whole request is enclosed in single transaction. The problem is that upon order.delete() I get: ... File "/usr/local/lib/python2.6/dist-packages/django/db/backends/__init__.py", line 28, in _commit return self.connection.commit() IntegrityError: update or delete on table "main_order" violates foreign key constraint "main_shipment_order_id_fkey" on table "main_shipment" DETAIL: Key (id)=(45) is still referenced from table "main_shipment". I checked in connection.queries that proper queries are executed in proper order. First shipment is deleted, after that django executes delete on order row: {'time': '0.000', 'sql': 'DELETE FROM "main_shipment" WHERE "id" IN (17)'}, {'time': '0.000', 'sql': 'DELETE FROM "main_order" WHERE "id" IN (45)'} Foreign key have ON DELETE NO ACTION (default) and is initially deferred. I don't know why I get foreign key constraint violation. I also tried to register pre_delete signal and manually delete shipment objects before delete on order is called, but it resulted in the same error. I can change ON DELETE behaviour for this key in Postgres but it would be just a hack, I wonder if anyone has a better idea what's going on here. There is also a small detail, my Order model inherits from Cart model, so it actually doesn't have id field but cart_ptr_id and after DELETE on order is executed there is also DELETE on cart, but it seems unrelated? to the shipment-order problem so I simplified it in the example.

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  • Hibernate overriding database modifications with detached object state

    - by EugeneP
    I'm gonna go with this design: create an object and keep it alive during all web-app session. And I need to synchronize its state with database state. What I want to achieve is that : IF between my db operations, that is, modifications that I persist to a db someone intentionally spoils table rows, then on next saving to a database all those changes WOULD BE OVERWRITTEN with the object state, that always contains valid data. What Hibernate methods do you recommend me to use to persist the modifications in a database? saveOrUpdate() is a possible solution, but maybe there's anything better? Again, I repeat how it looks. First I create an object without collections. Persist it (save()). Then user provides us with additional data. In a serviceLayer, again, we modify our object in memory (say, populate it with collections) and then, persist it again. So every serviceLayer operation of the next step must simply guarantee that database contains the exact persistent copy of this object that we have in memory. If data in a database differ, it MUST BE OVERRIDDEN with the object (kept in memory) state. What Session operations do you recommend?

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  • Django: Overriding the save() method: how do I call the delete() method of a child class

    - by Patti
    The setup = I have this class, Transcript: class Transcript(models.Model): body = models.TextField('Body') doPagination = models.BooleanField('Paginate') numPages = models.PositiveIntegerField('Number of Pages') and this class, TranscriptPages(models.Model): class TranscriptPages(models.Model): transcript = models.ForeignKey(Transcript) order = models.PositiveIntegerField('Order') content = models.TextField('Page Content', null=True, blank=True) The Admin behavior I’m trying to create is to let a user populate Transcript.body with the entire contents of a long document and, if they set Transcript.doPagination = True and save the Transcript admin, I will automatically split the body into n Transcript pages. In the admin, TranscriptPages is a StackedInline of the Transcript Admin. To do this I’m overridding Transcript’s save method: def save(self): if self.doPagination: #do stuff super(Transcript, self).save() else: super(Transcript, self).save() The problem = When Transcript.doPagination is True, I want to manually delete all of the TranscriptPages that reference this Transcript so I can then create them again from scratch. So, I thought this would work: #do stuff TranscriptPages.objects.filter(transcript__id=self.id).delete() super(Transcript, self).save() but when I try I get this error: Exception Type: ValidationError Exception Value: [u'Select a valid choice. That choice is not one of the available choices.'] ... and this is the last thing in the stack trace before the exception is raised: .../django/forms/models.py in save_existing_objects pk_value = form.fields[pk_name].clean(raw_pk_value) Other attempts to fix: t = self.transcriptpages_set.all().delete() (where self = Transcript from the save() method) looping over t (above) and deleting each item individually making a post_save signal on TranscriptPages that calls the delete method Any ideas? How does the Admin do it? UPDATE: Every once in a while as I'm playing around with the code I can get a different error (below), but then it just goes away and I can't replicate it again... until the next random time. Exception Type: MultiValueDictKeyError Exception Value: "Key 'transcriptpages_set-0-id' not found in " Exception Location: .../django/utils/datastructures.py in getitem, line 203 and the last lines from the trace: .../django/forms/models.py in _construct_form form = super(BaseInlineFormSet, self)._construct_form(i, **kwargs) .../django/utils/datastructures.py in getitem pk = self.data[pk_key]

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