Search Results

Search found 24560 results on 983 pages for 'memory model'.

Page 329/983 | < Previous Page | 325 326 327 328 329 330 331 332 333 334 335 336  | Next Page >

• Specification, modeling and programming are principially the same, right?

  - by Gabriel Šcerbák

  In formal specifications based on abstract algebraic types and equational theory you use formulas of equational theory to specify theory. System which will satisfy those constraints is called in formal logic a model. Modeling is process of creating a model, which abstracts of some aspects, which are unnecessary details for a specific case. So concrete system has to adhere to created model in observed aspects. Programming is a process of creating a program which will have specific behaviour - will perform specific algorithms - and programming languages through different paradigms enable us to think in a certain specific way, which abstracts of some details, usually machine specific ones. So could we be doing all those things at the same time, because they are principially the same? Is declarative programming the nearest attempt to do that? Could we use some sort f programming languages which will be good for programming as well as for modeling and specification?

  Read the article

• Rails AR validates_uniqueness_of against polymorphic relationship

  - by aaronrussell

  Is it posible to validate the uniqueness of a child model's attribute scoped against a polymorphic relationship? For example I have a model called field that belongs to fieldable: class Field < ActiveRecord::Base belongs_to :fieldable, :polymorphic => :true validates_uniqueness_of :name, :scope => :fieldable_id end I have several other models (Pages, Items) which have many Fields. So what I want is to validate the uniqueness of the field name against the parent model, but the problem is that occasionally a Page and an Item share the same ID number, causing the validations to fail when they shouldn't. Am I just doing this wrong or is there a better way to do this?

  Read the article

• How to limit choice field options based on another choice field in django admin

  - by umnik700

  I have the following models: class Category(models.Model): name = models.CharField(max_length=40) class Item(models.Model): name = models.CharField(max_length=40) category = models.ForeignKey(Category) class Demo(models.Model): name = models.CharField(max_length=40) category = models.ForeignKey(Category) item = models.ForeignKey(Item) In the admin interface when creating a new Demo, after user picks category from the dropdown, I would like to limit the number of choices in the "items" drop-down. If user selects another category then the item choices should update accordingly. I would like to limit item choices right on the client, before it even hits the form validation on the server. This is for usability, because the list of items could be 1000+ being able to narrow it down by category would help to make it more manageable. Is there a "django-way" of doing it or is custom JavaScript the only option here?

  Read the article

• Is System.AddIn mostly about making it easier to use Remoting or does it make it harder to do so?

  - by MatthewMartin

  It takes at least 7 assemblies and restricting my AddIn's data model to data types that remoting can deal with before the appdomain isolation features begin to work. It is so complex! The System.AddIn teams blog implies to me they were trying to re-create a mental model of COM, a model I never understood very well in the first place and am not sold on the benefits. (If COM is so good why's it dead?-rhetorical question.) If I don't need to mirror or interop with legacy COM (like VSTO does using System.AddIn), is it possible to just create some classes that load load in a new AppDomain? I can write the discovery code my self, I've done it before and a naive implementation is pretty fast because I'm not like iterating over the assemblies in the GAC! So my specific question is, can I get the AppDomain isolation that AddIns provide with a few code Remoting snippets, and what would those be?

  Read the article

• Garbage collection of Strings returned from C# method calls in ascx pages

  - by Icarus

  Hi, For a web application developed on ASP.NET, we are finding that for user control files (ascx) we are returning long strings as a result of method calls. These are embedded in the ascx pages using the special tags <% %> When performing memory dump analysis for the application, we find that many of those strings are not being garbage collected. Also, the ascx pages are compiled to temporary DLLs and they are held in memory. Is this responsible for causing the long strings to remain in memory and not be garbage collected ? Note : The strings are larger than 85K in size.

  Read the article

• GDB hardware watchpoint very slow - why?

  - by Laurynas Biveinis

  On a large C application, I have set a hardware watchpoint on a memory address as follows: (gdb) watch *((int*)0x12F5D58) Hardware watchpoint 3: *((int*)0x12F5D58) As you can see, it's a hardware watchpoint, not software, which would explain the slowness. Now the application running time under debugger has changed from less than ten seconds to one hour and counting. The watchpoint has triggered three times so far, the first time after 15 minutes when the memory page containing the address was made readable by sbrk. Surely during those 15 minutes the watchpoint should have been efficient since the memory page was inaccessible? And that still does not explain, why it's so slow afterwards. The GDB is $ gdb --version GNU gdb (GDB) 7.0-ubuntu [...] Thanks in advance for any ideas as what might be the cause or how to fix/work around it.

  Read the article

• LRU caches in C

  - by lazyconfabulator

  I need to cache a large (but variable) number of smallish (1 kilobyte to 10 megabytes) files in memory, for a C application (in a *nix environment). Since I don't want to eat all my memory, I'd like to set hard memory limit (say, 64 megabytes) and push files into a hash table with the file name as the key and dispose of the entries with the least use. What I believe I need is an LRU cache. Really, I'd rather not roll my own so if someone knows where I can find a workable library, please point the way? Failing that, can someone provide a simple example of an LRU cache in C? Related posts indicated that a hash table with a doubly-linked list, but I'm not even clear on how a doubly-linked list keeps LRU. Side note: I realize this is almost exactly the function of memcache, but it's not an option for me. I also took a look at the source hoping to enlighten myself on LRU caching, with no success.

  Read the article

• How do I prevent a ManyToManyField('self') from linked an object to itself?

  - by dyve

  Consider this model (simplified for this question): class SecretAgentName(models.Model): name = models.CharField(max_length=100) aliases = ManyToManyField('self') I have three names, "James Bond", "007" and "Jason Bourne". "James Bond" and "007" are aliases of each other. This works exactly like I want it to, except for the fact that every instance can also be an alias of itself. This I want to prevent. So, there can be many SecretAgentNames, all can be aliases of each other as long as "James Bond" does not show up as an alias for "James Bond". Can I prevent this in the model definition? If not, can I prevent it anywhere else, preferably so that the Django Admin understands it?

  Read the article

• How to organize asp.net mvc project (using entity framework) and a corresponding database project?

  - by Bernie

  I recently switched to vs2010 and am experimenting with asp.net MVC2. I am building a simple website and use the entity framework to design the data model. From the .edmx file, I generate the database tables. After a few iterations, I decided that it would be nice to have version control of the database schema as well, and therefore I added a database project into which I imported the script that is generated from the datamodel. As a result, I have to generate the sql every time that I change the model and redo the import. The database project automatically updates the database. Although the manual steps to generate the sql and the import are annoying, this works pretty well, until I wanted to add the standard tables for user accounts/authorization etc. I can use the framework tools to add the necessary tables, views etc. to the database, but as I do not want to have them in the .edmx model I end up with a third manual step. Is anybody facing similar issues?

  Read the article

• Django save, column specified twice

  - by realshadow

  Hey, I would like to save a modified model, but I get Programming error - that a field is specified twice. class ProductInfo(models.Model): product_info_id = models.AutoField(primary_key=True) language_id = models.IntegerField() product_id = models.IntegerField() description = models.TextField(blank=True) status = models.IntegerField() model = models.CharField(max_length=255, blank=True) label = models.ForeignKey(Category_info, verbose_name = 'Category_info', db_column = 'language_id', to_field = 'node_id', null = True) I get this error because the foreign key uses as db_column language_id. If I will delete it, my object will be saved properly. I dont quite understand whats going on and since I have defined almost all of my models this way, I fear its totally wrong or maybe I just missunderstood it... Any ideas? Regards

  Read the article

• Conditional relation

  - by Lowgain

  I've got a model like this: Stem -id -etc And then I have Stemrelation -stem_id -related_stem_id -active I can get the related stems with the following relations class Stem < ActiveRecord::Base has_many :stemrelations has_many :related_stems, :through => :stemrelations end class Stemrelation < ActiveRecord::Base belongs_to :stem belongs_to :related_stem, :class_name => "Stem", :foreign_key => "related_stem_id" end But now I'd only like to get the active relations. I tried adding this to the Stem model: has_many :active_related, :through => :stemrelations, :source => :related_stem, :conditions => {:active => true} but this gives me an error becasue it tries to check the active flag on the stem model instead of the stemrelation. What do I change here? Thanks!

  Read the article

• mvc components in codeigniter?

  - by ajsie

  in yii i could have mvc components (acts like an own application). could i have this too in codeigniter? eg. in SYSTEM/APPLICATION have a folder called COMPONENTS and in there i put stand-alone applications that would be a part of the application. components like ADDRESS BOOK, MAIL, TWITTER and so on. every component folder has folders like: models, views, controllers, config etc. so a component model extends the application model which in turn extends system's (code igniter) model. the same goes for view and controller. i've already got a lot of these components which i want to use in codeigniter. is it good idea to place them as i said in SYSTEM/APPLICATION/COMPONENTS or is there best practice for this?

  Read the article

• Catch PyGTK TreeView reorder

  - by mkotechno

  I have a simple gtk.TreeView with a gtk.ListStore model and set_reorderable(True), I want to catch the signal/event emited when the user reorder through drag&drop the list, but the documentation does not help much: "The application can listen to these changes by connecting to the model's signals" So I tried to connect the model (ListStore) signals... but surprise! ListStore has no signals, so you are dispatched to TreeModel signals, then I tried to connect with the TreeModel "rows-reordered" signal with no lucky. How should I catch the list reorder performed by the user?

  Read the article

• how to get obj2.name via obj1.categories(), thanks (gae python)

  - by zjm1126

  i using google-app-engine webapp ,code is : class Post(db.Model): title = db.StringProperty(required=True) def categories(self): return (x.category for x in self.postcategory_set) class Category(db.Model): name = db.StringProperty() class PostCategory(db.Model): post = db.ReferenceProperty(Post) category = db.ReferenceProperty(Category) class sss(webapp.RequestHandler): def get(self): obj1 = Post(title='hhaa') #obj1.title = 'haha' obj1.put() obj2 = Category() obj2.name='haha-kao' obj2.put() obj3=PostCategory() obj3.post=obj1 obj3.category=obj2 obj3.put() self.response.out.write(obj1.categories().get().name) the error is : Traceback (most recent call last): File "D:\Program Files\Google\google_appengine\google\appengine\ext\webapp\__init__.py", line 511, in __call__ handler.get(*groups) File "D:\zjm_code\helloworld\a.py", line 131, in get self.response.out.write(obj1.categories().get().name) AttributeError: 'generator' object has no attribute 'get' so how to get the obj2.name via obj1's method thanks

  Read the article

• Needing to copy properties before validation

  - by Mikael

  I have a farily complex model needing to be validated, the problem is that this model is used on two different places, one where you register your customer and one where you simply add addresses. Some fields on the address are simply not visible on the register customer form. So when i check if ModelState.IsValid i get false of course since eg. the name is not entered on the billing address, but it is on the customer. That is why i want to before validation occurs, copy a couple of fields to the model, and then validate. I am somewhat lost though and i need help. My action looks something like this: public ActionResult Register(WebCustomer customer) { customer.CopyProperties(); if(TryUpdateModel(customer)) { ... } ... But it always returns false, and ModelState.IsValid continues to be false.

  Read the article

• Emacs & PHP indenting question

  - by Danny

  Hi all, I'm a bit new to using emacs for webdevelopment. I am using php-mode and i am happy with it. There is only one issue i have which causes me a lot of problems because of our company's coding style. When i have a function, e.g.: $instance = new Model('foo', 'bar'); And I want to indent it like this: $instance = new Model( 'foo', 'bar' ); Emacs does the following when i insert a newline before the first argument and indents it like this: $instance = new Model( 'foo', 'bar' ); Can anyone point me in a direction on how i can configure/change this? Thanks in advance

  Read the article

• Entity Framework: Data Centric vs. Object Centric

  - by Eric J.

  I'm having a look at Entity Framework and everything I'm reading takes a data centric approach to explaining EF. By that I mean that the fundamental relationships of the system are first defined in the database and objects are generated that reflect those relationships. Examples Quickstart (Entity Framework) Using Entity Framework entities as business objects? The EF documentation implies that it's not necessary to start from the database layer, e.g. Developers can work with a consistent application object model that can be mapped to various storage schemas When designing a new system (simplified version), I tend to first create a class model, then generate business objects from the model, code business layer stuff that can't be generated, and then worry about persistence (or rather work with a DBA and let him worry about the most efficient persistence strategy). That object centric approach is well supported by ORM technologies such as (n)Hibernate. Is there a reasonable path to an object centric approach with EF? Will I be swimming upstream going that route? Any good starting points?

  Read the article

• Valid Dates in AppEngine forms (Beginner)

  - by codingJoe

  In AppEngine, I have a form that prompts a user for a date. The problem is that when the clicks enter there is an error: "Enter a Valid Date" How do I make my Form accept (for example) %d-%b-%Y as the date format? Is there a more elegant way to accomplish this? # Model and Forms class Task(db.Model): name=db.StringProperty() due=db.DateProperty() class TaskForm(djangoforms.ModelForm): class Meta: model = Task # my get function has the following. # using "now" for example. Could just as well be next Friday. tmStart = datetime.now() form = TaskForm(initial={'due': tmStart.strftime("%d-%b-%Y")}) template_values = {'form': form }

  Read the article

• Implements an Undo/Redo in MVC

  - by bnabilos

  Hello, I have a Java application and I want to implement an Undo/Redo option. the value that I want to stock and that I want to be able to recover is an integer. My Class Model implements the interface StateEditable and I have to redefine the 2 functions restoreState(Hashtable<?, ?> state) and storeState(Hashtable<Object, Object> state) but I don't know what to put on them. It will be really great if somebody can help me to do that. These are the first lines of my Model class, the value that I want to do an undo/redo on it is value public class Model extends Observable implements StateEditable { private int value = 5; private UndoManager undoRedo = new UndoManager(); final UndoableEditListener editListener = new UndoableEditListener() { public void undoableEditHappened(UndoableEditEvent evt) { undoRedo.addEdit(evt.getEdit()); } }; @Override public void restoreState(Hashtable<?, ?> state) { } @Override public void storeState(Hashtable<Object, Object> state) { } }

  Read the article

• Two models, one STI and a Validation

  - by keruilin

  Let's say I have two tables -- Products and Orders. For the sake of simplicity assume that only one product can be purchased at a time so there is no join table like order_items. So the relationship is that Product has many orders, and Order belongs to product. Therefore, product_id is a fk in the Order table. The product table is STI -- with the subclasses being A, B, C. When the user orders subclass Product C, two special validations must be checked on the Order model fields order_details and order_status. These two fields can be nil for all other Product subclasses (ie A and B). In other words, no validation needs to run for these two fields when a user purchases A and B. My question is: How do I write validations (perhaps custom?) in the Order model so that the Order model knows to only run the validations for the two fields -- order_details and order_status -- when Product subclass C is being saved to the orders table?

  Read the article

• Apache Prefork Configuration

  - by user1618606

  I'm newbie on VPS configuration. So, I've installed apache, php and mysql and now I need to know how to configure Prefork to optimize Apache. The system configuration is: CPU Cores 2 x 2 Ghz @ 4 Ghz RAM Memory 2304 MB DDR3 Burst Memory 3 GB DDR3 Disk Space 30 GB SSD Bandwidth 3 TB SwitchPort 1 Gbps Actually, after linux, mysql, apache and php, there are 250 MB memory in use. Well, I don't have idea to calculate. I saw in some websistes, some vars like: KeepAlive On KeepAliveTimeout 1 MaxKeepAliveRequests 100 StartServers 15 MinSpareServers 15 MaxSpareServers 15 MaxClients 20 MaxRequestsPerChild 0 or StartServers 2 MaxClients 150 MinSpareThreads 25 MaxSpareThreads 75 ThreadsPerChild 25 MaxRequestsPerChild 0 How I could to do: Prefork or worker? Where and how the vars are placed? In httpd.conf? Big hug, Claudio.

  Read the article

• Sort tables with two elements

  - by Mercer

  Hello i want to make a sort in java. In my object i have many element so i want to make this sort with power and model public class Product implements Comparable<Product>,Serializable { private int idProduct ; private int power; private String model; private String color; [...] @Override public int compareTo(Product o) { return String.valueOf(this.power).compareTo(String.valueOf(o.power)); } so how to make sort with power and model

  Read the article

• Best way of implementing DropDownList in ASP.NET MVC 2?

  - by Kelsey

  I am trying to understand the best way of implementing a DropDownList in ASP.NET MVC 2 using the DropDownListFor helper. This is a multi-part question. First, what is the best way to pass the list data to the view? Pass the list in your model with a SelectList property that contains the data Pass the list in via ViewData How do I get a blank value in the DropDownList? Should I build it into the SelectList when I am creating it or is there some other means to tell the helper to auto create an empty value? Lastly, if for some reason there is a server side error and I need to redisplay the screen with the DropDownList, do I need to fetch the list values again to pass into the view model? This data is not maintained between posts (at least not when I pass it via my view model) so I was going to just fetch it again (it's cached). Am I going about this correctly?

  Read the article

• Types in Python - Google Appengine

  - by Chris M

  Getting a bit peeved now; I have a model and a class thats just storing a get request in the database; basic tracking. class SearchRec(db.Model): WebSite = db.StringProperty()#required=True WebPage = db.StringProperty() CountryNM = db.StringProperty() PrefMailing = db.BooleanProperty() DateStamp = db.DateTimeProperty(auto_now_add=True) IP = db.StringProperty() class AddSearch(webapp.RequestHandler): def get(self): searchRec = SearchRec() searchRec.WebSite = self.request.get('WEBSITE') searchRec.WebPage = self.request.get('WEBPAGE') searchRec.CountryNM = self.request.get('COUNTRY') searchRec.PrefMailing = bool(self.request.get('MAIL')) searchRec.IP = self.request.get('IP') Bool has my biscuit; I thought that setting bool(self.reque....) would set the type of the string but no matter what I pass it it still stores it as TRUE in the database. I had the same issue with using required=True on strings for the model; the damn thing kept saying that nothing was being passed... but it had. Ta

  Read the article

• YII Mail Generate unwanted ascii character in HTML mail

  - by CedSha

  I use YII-Mail just by copying the sample but I always get some ascii charcters in my generated links Where they come from and how to avoid them ? $message = new YiiMailMessage; $message->view = 'mail'; $message->setBody(array('model'=>$model), 'text/html'); $message->subject = Yii::t('tr','my subject'); $message->addTo('[email protected]'); $message->from = '[email protected]'; Yii::app()->mail->send($message); and in view file 'mail' <h1><?php echo(Yii::t('tr','This is HTML mail')); ?></h1> <?php echo CHtml::link('Mylink', array('controller/view', 'id'=>$model->id)); ?> The resulted email source looks like this <h1>This is HTML mail</h1> <a href=3D"/testdrive/index.php?r=3D ....

  Read the article

< Previous Page | 325 326 327 328 329 330 331 332 333 334 335 336  | Next Page >