Search Results

Search found 8330 results on 334 pages for 'template inheritance'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 4/334 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • C++: Declaration of template class member specialization

    - by Ziv
    When I specialize a (static) member function/constant in a template class, I'm confused as to where the declaration is meant to go. Here's an example of what I what to do - yoinked directly from IBM's reference on template specialization: ===IBM Member Specialization Example=== template<class T> class X { public: static T v; static void f(T); }; template<class T> T X<T>::v = 0; template<class T> void X<T>::f(T arg) { v = arg; } template<> char* X<char*>::v = "Hello"; template<> void X<float>::f(float arg) { v = arg * 2; } int main() { X<char*> a, b; X<float> c; c.f(10); // X<float>::v now set to 20 } The question is, how do I divide this into header/cpp files? The generic implementation is obviously in the header, but what about the specialization? It can't go in the header file, because it's concrete, leading to multiple definition. But if it goes into the .cpp file, is code which calls X::f() aware of the specialization, or might it rely on the generic X::f()? So far I've got the specialization in the .cpp only, with no declaration in the header. I'm not having trouble compiling or even running my code (on gcc, don't remember the version at the moment), and it behaves as expected - recognizing the specialization. But A) I'm not sure this is correct, and I'd like to know what is, and B) my Doxygen documentation comes out wonky and very misleading (more on that in a moment a later question). What seems most natural to me would be something like this, declaring the specialization in the header and defining it in the .cpp: ===XClass.hpp=== #ifndef XCLASS_HPP #define XCLASS_HPP template<class T> class X { public: static T v; static void f(T); }; template<class T> T X<T>::v = 0; template<class T> void X<T>::f(T arg) { v = arg; } /* declaration of specialized functions */ template<> char* X<char*>::v; template<> void X<float>::f(float arg); #endif ===XClass.cpp=== #include <XClass.hpp> /* concrete implementation of specialized functions */ template<> char* X<char*>::v = "Hello"; template<> void X<float>::f(float arg) { v = arg * 2; } ...but I have no idea if this is correct. Any ideas? Thanks much, Ziv

    Read the article

  • die $template->error() produces no line number

    - by Kinopiko
    In the following short program: use Template; my $template = Template->new (INCLUDE_PATH => "."); $template->process ("non-existent-file") or die $template->error (); why does "die" not produce a line number and newline? Output looks like this: $ perl template.pl file error - non-existent-file: not found ~ 503 $

    Read the article

  • Issue with class template partial specialization

    - by DeadMG
    I've been trying to implement a function that needs partial template specializations and fallen back to the static struct technique, and I'm having a number of problems. template<typename T> struct PushImpl<const T&> { typedef T* result_type; typedef const T& argument_type; template<int StackSize> static result_type Push(IStack<StackSize>* sptr, argument_type ref) { // Code if the template is T& } }; template<typename T> struct PushImpl<const T*> { typedef T* result_type; typedef const T* argument_type; template<int StackSize> static result_type Push(IStack<StackSize>* sptr, argument_type ptr) { return PushImpl<const T&>::Push(sptr, *ptr); } }; template<typename T> struct PushImpl { typedef T* result_type; typedef const T& argument_type; template<int StackSize> static result_type Push(IStack<StackSize>* sptr, argument_type ref) { // Code if the template is neither T* nor T& } }; template<typename T> typename PushImpl<T>::result_type Push(typename PushImpl<T>::argument_type ref) { return PushImpl<T>::Push(this, ref); } First: The struct is nested inside another class (the one that offers Push as a member func), but it can't access the template parameter (StackSize), even though my other nested classes all could. I've worked around it, but it would be cleaner if they could just access StackSize like a normal class. Second: The compiler complains that it doesn't use or can't deduce T. Really? Thirdly: The compiler complains that it can't specialize a template in the current scope (class scope). I can't see what the problem is. Have I accidentally invoked some bad syntax?

    Read the article

  • SFINAE failing with enum template parameter

    - by zeroes00
    Can someone explain the following behaviour (I'm using Visual Studio 2010). header: #pragma once #include <boost\utility\enable_if.hpp> using boost::enable_if_c; enum WeekDay {MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY}; template<WeekDay DAY> typename enable_if_c< DAY==SUNDAY, bool >::type goToWork() {return false;} template<WeekDay DAY> typename enable_if_c< DAY!=SUNDAY, bool >::type goToWork() {return true;} source: bool b = goToWork<MONDAY>(); compiler this gives error C2770: invalid explicit template argument(s) for 'enable_if_c<DAY!=6,bool>::type goToWork(void)' and error C2770: invalid explicit template argument(s) for 'enable_if_c<DAY==6,bool>::type goToWork(void)' But if I change the function template parameter from the enum type WeekDay to int, it compiles fine: template<int DAY> typename enable_if_c< DAY==SUNDAY, bool >::type goToWork() {return false;} template<int DAY> typename enable_if_c< DAY!=SUNDAY, bool >::type goToWork() {return true;} Also the normal function template specialization works fine, no surprises there: template<WeekDay DAY> bool goToWork() {return true;} template<> bool goToWork<SUNDAY>() {return false;} To make things even weirder, if I change the source file to use any other WeekDay than MONDAY or TUESDAY, i.e. bool b = goToWork<THURSDAY>(); the error changes to this: error C2440: 'specialization' : cannot convert from 'int' to 'const WeekDay' Conversion to enumeration type requires an explicit cast (static_cast, C-style cast or function-style cast)

    Read the article

  • Specializing a template member function of a template class?

    - by uj2
    I have a template class that has a template member function that needs to be specialized, as in: template <typename T> class X { public: template <typename U> void Y() {} template <> void Y<int>() {} }; Altough VC handles this correctly, apperantly this isn't standard and GCC complains: explicit specialization in non-namespace scope 'class X<T>' I tried: template <typename T> class X { public: template <typename U> void Y() {} }; template <typename T> // Also tried `template<>` here void X<T>::Y<int>() {} But this causes both VC and GCC to complain. What's the right way to do this?

    Read the article

  • vSphere Client vCenter Template Customization Specification Using Windows Sysprep Unattended Answer XML File

    - by Brian
    I'm trying to setup a vSphere Client vCenter v5.0.0 Build 455964 Template Customization Specification using a Windows Sysprep unattended answer XML file for Win2008R2. However I didn't know how Sysprep worked before attempting this so it was a time-consuming nightmare (even after reviewing VMware vSphere ESXi 5's documentation)! I think I've figure out what I'm supposed to be doing, but it's still not working. The biggest problem at this point is that vSphere Client vCenter Customization Specification IP address information is not sticking when I load a Sysprep XML file with just 1 basic setting! This can only be a bug. Here is the process I'm using: PROCESS for Windows - vSphere Client Install Windows OS install VM Tools customize Windows (GPOs can be used to do this after deployment) install Applications (GPOs can be used to do this after deployment too) shutdown the VM convert the VM to a template create a custom Windows Sysprep XML answer file with desired customizations View Management Customization Specifications Manager create "New" Specification for "Target Virtual Machine OS" select Windows check "Use Custom Sysprep Answer File" (ADDS: Custom Sysprep File. KEEPS: Network (IP), Operating System Options (SID, Sysprep /generalize). REPLACES: Registration Information of Owner Name & Organization, Computer Name, Windows License (Key), Administrator Password, Time Zone, Run Once, Workgroup or Domain) name it as "VMwareCS-OS####R#x32/64w/Sysprep-TEST" (CS=Customization Specification) set Description as "Created YYYY/MM/DD by FLast" NEXT import a Sysprep answer file from secure location NEXT Custom settings NEXT click "..." box to right of "Use DHCP" set "Use the following IP settings:" for "IP Address" fill out the first 2 octets set appropriate values for other 2-3 fields set DNS server addresses OK NEXT check "Generate New Security ID (SID)" ALWAYS as template is likely a domain-member computer so it can be updated occasionally NEXT Finish View Inventory VMs and Templates right-click previously completed template Deploy Virtual Machine from this Template provide the new OS name (max15char) select inventory location NEXT select Host/Cluster (wait for validation to succeed) NEXT select Resource Pool (wait for validation to succeed) NEXT select Storage location NEXT check "Power on this virtual machine after creation" select "Customize using an existing customization specification" select desired specification select "Use the Customization Wizard to temporarily adjust the specification before deployment" NEXT NEXT Custom settings? NEXT check "Generate New Security ID (SID)" ALWAYS as template is likely a domain-member computer so it can be updated occasionally NEXT Finish Finish. I know a community member named "brian" (http://serverfault.com/users/25904/brian) has worked with this scenario before, but I couldn't figure out how to contact him directly, so Brian if you see this message could you provide some information to help? Thanks, Brian

    Read the article

  • eclipse template autoformat [closed]

    - by Matiaan
    I have a template (sleep) in eclipse that should expand to try { Thread.sleep(1000); } catch (Exception e) {} I want eclipse to add it as one line, just as I put it in the template. However, eclipse autoformats it after inserting to: try { Thread.sleep(1000); } catch (Exception e) { } Is there any way to disable formatting just for this one template (or all templates since all templates I use are one liners)?

    Read the article

  • Inheritance Mapping Strategies with Entity Framework Code First CTP5 Part 1: Table per Hierarchy (TPH)

    - by mortezam
    A simple strategy for mapping classes to database tables might be “one table for every entity persistent class.” This approach sounds simple enough and, indeed, works well until we encounter inheritance. Inheritance is such a visible structural mismatch between the object-oriented and relational worlds because object-oriented systems model both “is a” and “has a” relationships. SQL-based models provide only "has a" relationships between entities; SQL database management systems don’t support type inheritance—and even when it’s available, it’s usually proprietary or incomplete. There are three different approaches to representing an inheritance hierarchy: Table per Hierarchy (TPH): Enable polymorphism by denormalizing the SQL schema, and utilize a type discriminator column that holds type information. Table per Type (TPT): Represent "is a" (inheritance) relationships as "has a" (foreign key) relationships. Table per Concrete class (TPC): Discard polymorphism and inheritance relationships completely from the SQL schema.I will explain each of these strategies in a series of posts and this one is dedicated to TPH. In this series we'll deeply dig into each of these strategies and will learn about "why" to choose them as well as "how" to implement them. Hopefully it will give you a better idea about which strategy to choose in a particular scenario. Inheritance Mapping with Entity Framework Code FirstAll of the inheritance mapping strategies that we discuss in this series will be implemented by EF Code First CTP5. The CTP5 build of the new EF Code First library has been released by ADO.NET team earlier this month. EF Code-First enables a pretty powerful code-centric development workflow for working with data. I’m a big fan of the EF Code First approach, and I’m pretty excited about a lot of productivity and power that it brings. When it comes to inheritance mapping, not only Code First fully supports all the strategies but also gives you ultimate flexibility to work with domain models that involves inheritance. The fluent API for inheritance mapping in CTP5 has been improved a lot and now it's more intuitive and concise in compare to CTP4. A Note For Those Who Follow Other Entity Framework ApproachesIf you are following EF's "Database First" or "Model First" approaches, I still recommend to read this series since although the implementation is Code First specific but the explanations around each of the strategies is perfectly applied to all approaches be it Code First or others. A Note For Those Who are New to Entity Framework and Code-FirstIf you choose to learn EF you've chosen well. If you choose to learn EF with Code First you've done even better. To get started, you can find a great walkthrough by Scott Guthrie here and another one by ADO.NET team here. In this post, I assume you already setup your machine to do Code First development and also that you are familiar with Code First fundamentals and basic concepts. You might also want to check out my other posts on EF Code First like Complex Types and Shared Primary Key Associations. A Top Down Development ScenarioThese posts take a top-down approach; it assumes that you’re starting with a domain model and trying to derive a new SQL schema. Therefore, we start with an existing domain model, implement it in C# and then let Code First create the database schema for us. However, the mapping strategies described are just as relevant if you’re working bottom up, starting with existing database tables. I’ll show some tricks along the way that help you dealing with nonperfect table layouts. Let’s start with the mapping of entity inheritance. -- The Domain ModelIn our domain model, we have a BillingDetail base class which is abstract (note the italic font on the UML class diagram below). We do allow various billing types and represent them as subclasses of BillingDetail class. As for now, we support CreditCard and BankAccount: Implement the Object Model with Code First As always, we start with the POCO classes. Note that in our DbContext, I only define one DbSet for the base class which is BillingDetail. Code First will find the other classes in the hierarchy based on Reachability Convention. public abstract class BillingDetail  {     public int BillingDetailId { get; set; }     public string Owner { get; set; }             public string Number { get; set; } } public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } } public class CreditCard : BillingDetail {     public int CardType { get; set; }                     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } } public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; } } This object model is all that is needed to enable inheritance with Code First. If you put this in your application you would be able to immediately start working with the database and do CRUD operations. Before going into details about how EF Code First maps this object model to the database, we need to learn about one of the core concepts of inheritance mapping: polymorphic and non-polymorphic queries. Polymorphic Queries LINQ to Entities and EntitySQL, as object-oriented query languages, both support polymorphic queries—that is, queries for instances of a class and all instances of its subclasses, respectively. For example, consider the following query: IQueryable<BillingDetail> linqQuery = from b in context.BillingDetails select b; List<BillingDetail> billingDetails = linqQuery.ToList(); Or the same query in EntitySQL: string eSqlQuery = @"SELECT VAlUE b FROM BillingDetails AS b"; ObjectQuery<BillingDetail> objectQuery = ((IObjectContextAdapter)context).ObjectContext                                                                          .CreateQuery<BillingDetail>(eSqlQuery); List<BillingDetail> billingDetails = objectQuery.ToList(); linqQuery and eSqlQuery are both polymorphic and return a list of objects of the type BillingDetail, which is an abstract class but the actual concrete objects in the list are of the subtypes of BillingDetail: CreditCard and BankAccount. Non-polymorphic QueriesAll LINQ to Entities and EntitySQL queries are polymorphic which return not only instances of the specific entity class to which it refers, but all subclasses of that class as well. On the other hand, Non-polymorphic queries are queries whose polymorphism is restricted and only returns instances of a particular subclass. In LINQ to Entities, this can be specified by using OfType<T>() Method. For example, the following query returns only instances of BankAccount: IQueryable<BankAccount> query = from b in context.BillingDetails.OfType<BankAccount>() select b; EntitySQL has OFTYPE operator that does the same thing: string eSqlQuery = @"SELECT VAlUE b FROM OFTYPE(BillingDetails, Model.BankAccount) AS b"; In fact, the above query with OFTYPE operator is a short form of the following query expression that uses TREAT and IS OF operators: string eSqlQuery = @"SELECT VAlUE TREAT(b as Model.BankAccount)                       FROM BillingDetails AS b                       WHERE b IS OF(Model.BankAccount)"; (Note that in the above query, Model.BankAccount is the fully qualified name for BankAccount class. You need to change "Model" with your own namespace name.) Table per Class Hierarchy (TPH)An entire class hierarchy can be mapped to a single table. This table includes columns for all properties of all classes in the hierarchy. The concrete subclass represented by a particular row is identified by the value of a type discriminator column. You don’t have to do anything special in Code First to enable TPH. It's the default inheritance mapping strategy: This mapping strategy is a winner in terms of both performance and simplicity. It’s the best-performing way to represent polymorphism—both polymorphic and nonpolymorphic queries perform well—and it’s even easy to implement by hand. Ad-hoc reporting is possible without complex joins or unions. Schema evolution is straightforward. Discriminator Column As you can see in the DB schema above, Code First has to add a special column to distinguish between persistent classes: the discriminator. This isn’t a property of the persistent class in our object model; it’s used internally by EF Code First. By default, the column name is "Discriminator", and its type is string. The values defaults to the persistent class names —in this case, “BankAccount” or “CreditCard”. EF Code First automatically sets and retrieves the discriminator values. TPH Requires Properties in SubClasses to be Nullable in the Database TPH has one major problem: Columns for properties declared by subclasses will be nullable in the database. For example, Code First created an (INT, NULL) column to map CardType property in CreditCard class. However, in a typical mapping scenario, Code First always creates an (INT, NOT NULL) column in the database for an int property in persistent class. But in this case, since BankAccount instance won’t have a CardType property, the CardType field must be NULL for that row so Code First creates an (INT, NULL) instead. If your subclasses each define several non-nullable properties, the loss of NOT NULL constraints may be a serious problem from the point of view of data integrity. TPH Violates the Third Normal FormAnother important issue is normalization. We’ve created functional dependencies between nonkey columns, violating the third normal form. Basically, the value of Discriminator column determines the corresponding values of the columns that belong to the subclasses (e.g. BankName) but Discriminator is not part of the primary key for the table. As always, denormalization for performance can be misleading, because it sacrifices long-term stability, maintainability, and the integrity of data for immediate gains that may be also achieved by proper optimization of the SQL execution plans (in other words, ask your DBA). Generated SQL QueryLet's take a look at the SQL statements that EF Code First sends to the database when we write queries in LINQ to Entities or EntitySQL. For example, the polymorphic query for BillingDetails that you saw, generates the following SQL statement: SELECT  [Extent1].[Discriminator] AS [Discriminator],  [Extent1].[BillingDetailId] AS [BillingDetailId],  [Extent1].[Owner] AS [Owner],  [Extent1].[Number] AS [Number],  [Extent1].[BankName] AS [BankName],  [Extent1].[Swift] AS [Swift],  [Extent1].[CardType] AS [CardType],  [Extent1].[ExpiryMonth] AS [ExpiryMonth],  [Extent1].[ExpiryYear] AS [ExpiryYear] FROM [dbo].[BillingDetails] AS [Extent1] WHERE [Extent1].[Discriminator] IN ('BankAccount','CreditCard') Or the non-polymorphic query for the BankAccount subclass generates this SQL statement: SELECT  [Extent1].[BillingDetailId] AS [BillingDetailId],  [Extent1].[Owner] AS [Owner],  [Extent1].[Number] AS [Number],  [Extent1].[BankName] AS [BankName],  [Extent1].[Swift] AS [Swift] FROM [dbo].[BillingDetails] AS [Extent1] WHERE [Extent1].[Discriminator] = 'BankAccount' Note how Code First adds a restriction on the discriminator column and also how it only selects those columns that belong to BankAccount entity. Change Discriminator Column Data Type and Values With Fluent API Sometimes, especially in legacy schemas, you need to override the conventions for the discriminator column so that Code First can work with the schema. The following fluent API code will change the discriminator column name to "BillingDetailType" and the values to "BA" and "CC" for BankAccount and CreditCard respectively: protected override void OnModelCreating(System.Data.Entity.ModelConfiguration.ModelBuilder modelBuilder) {     modelBuilder.Entity<BillingDetail>()                 .Map<BankAccount>(m => m.Requires("BillingDetailType").HasValue("BA"))                 .Map<CreditCard>(m => m.Requires("BillingDetailType").HasValue("CC")); } Also, changing the data type of discriminator column is interesting. In the above code, we passed strings to HasValue method but this method has been defined to accepts a type of object: public void HasValue(object value); Therefore, if for example we pass a value of type int to it then Code First not only use our desired values (i.e. 1 & 2) in the discriminator column but also changes the column type to be (INT, NOT NULL): modelBuilder.Entity<BillingDetail>()             .Map<BankAccount>(m => m.Requires("BillingDetailType").HasValue(1))             .Map<CreditCard>(m => m.Requires("BillingDetailType").HasValue(2)); SummaryIn this post we learned about Table per Hierarchy as the default mapping strategy in Code First. The disadvantages of the TPH strategy may be too serious for your design—after all, denormalized schemas can become a major burden in the long run. Your DBA may not like it at all. In the next post, we will learn about Table per Type (TPT) strategy that doesn’t expose you to this problem. References ADO.NET team blog Java Persistence with Hibernate book a { text-decoration: none; } a:visited { color: Blue; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } p.MsoNormal { margin-top: 0in; margin-right: 0in; margin-bottom: 10.0pt; margin-left: 0in; line-height: 115%; font-size: 11.0pt; font-family: "Calibri" , "sans-serif"; }

    Read the article

  • Exalogic 2.0.1 Tea Break Snippets - Modifying the Default Shipped Template

    - by The Old Toxophilist
    Having installed your Exalogic Virtual environment by default you have a single template which can be used to create your vServers. Although this template is suitable for creating simple test or development vServers it is recommended that you look at creating your own custom vServers that match the environment you wish to build and deploy. Therefore this Tea Time Snippet will take you through the simple process of modifying the standard template. Before You Start To edit the template you will need the Oracle ModifyJeos Utility which can be downloaded from the eDelivery Site. Once the ModifyJeos Utility has been downloaded we can install the rpms onto either an existing vServer or one of the Control vServers. rpm -ivh ovm-modify-jeos-1.0.1-10.el5.noarch.rpm rpm -ivh ovm-template-config-1.0.1-5.el5.noarch.rpm Alternatively you can install the modify jeos packages on a none Exalogic OEL installation or a VirtualBox image. If you are doing this, assuming OEL 5u8, you will need the following rpms. rpm -ivh ovm-modify-jeos-1.0.1-10.el5.noarch.rpm rpm -ivh ovm-el5u2-xvm-jeos-1.0.1-5.el5.i386.rpm rpm -ivh ovm-template-config-1.0.1-5.el5.noarch.rpm Base Template If you have installed the modify onto a vServer running on the Exalogic then simply mount the /export/common/images from the ZFS storage and you will be able to find the el_x2-2_base_linux_guest_vm_template_2.0.1.1.0_64.tgz (or similar depending which version you have) template file. Alternatively the latest can be downloaded from the eDelivery Site. Now we have the Template tgz we will need the extract it as follows: tar -zxvf  el_x2-2_base_linux_guest_vm_template_2.0.1.1.0_64.tgz This will create a directory called BASE which will contain the System.img (VServer image) and vm.cfg (VServer Config information). This directory should be renamed to something more meaning full that indicates what we have done to the template and then the Simple name / name in the vm.cfg editted for the same reason. Modifying the Template Resizing Root File System By default the shipped template has a root size of 4 GB which will leave a vServer created from it running at 90% full on the root disk. We can simply resize the template by executing the following: modifyjeos -f System.img -T <New Size MB>) For example to imcrease the default 4 GB to 40 GB we would execute: modifyjeos -f System.img -T 40960) Resizing Swap We can modify the size of the swap space within a template by executing the following: modifyjeos -f System.img -S <New Size MB>) For example to increase the swap from the default 512 MB to 4 GB we would execute: modifyjeos -f System.img -S 4096) Changing RPMs Adding RPMs To add RPMs using modifyjeos, complete the following steps: Add the names of the new RPMs in a list file, such as addrpms.lst. In this file, you should list each new RPM in a separate line. Ensure that all of the new RPMs are in a single directory, such as rpms. Run the following command to add the new RPMs: modifyjeos -f System.img -a <path_to_addrpms.lst> -m <path_to_rpms> -nogpg Where <path_to_addrpms.lst> is the path to the location of the addrpms.lst file, and <path_to_rpms> is the path to the directory that contains the RPMs. The -nogpg option eliminates signature check on the RPMs. Removing RPMs To remove RPM s using modifyjeos, complete the following steps: Add the names of the RPMs (the ones you want to remove) in a list file, such as removerpms.lst. In this file, you should list each RPM in a separate line. The Oracle Exalogic Elastic Cloud Administrator's Guide provides a list of all RPMs that must not be removed from the vServer. Run the following command to remove the RPMs: modifyjeos -f System.img -e <path_to_removerpms.lst> Where <path_to_removerpms.lst> is the path to the location of the removerpms.lst file. Mounting the System.img For all other modifications that are not supported by the modifyjeos command (adding you custom yum repositories, pre configuring NTP, modify default NFSv4 Nobody functionality, etc) we can mount the System.img and access it directly. To facititate quick and easy mounting/unmounting of the System.img I have put together the simple scripts below. MountSystemImg.sh #!/bin/sh # The script assumes it's being run from the directory containing the System.img # Export for later i.e. during unmount export LOOP=`losetup -f` export SYSTEMIMG=/mnt/elsystem # Make Temp Mount Directory mkdir -p $SYSTEMIMG # Create Loop for the System Image losetup $LOOP System.img kpartx -a $LOOP mount /dev/mapper/`basename $LOOP`p2 $SYSTEMIMG #Change Dir into mounted Image cd $SYSTEMIMG UnmountSystemImg.sh #!/bin/sh # The script assumes it's being run from the directory containing the System.img # Assume the $LOOP & $SYSTEMIMG exist from a previous run on the MountSystemImg.sh umount $SYSTEMIMG kpartx -d $LOOP losetup -d $LOOP Packaging the Template Once you have finished modifying the template it can be simply repackaged and then imported into EMOC as described in "Exalogic 2.0.1 Tea Break Snippets - Importing Public Server Template". To do this we will simply cd to the directory above that containing the modified files and execute the following: tar -zcvf <New Template Directory> <New Template Name>.tgz The resulting.tgz file can be copied to the images directory on the ZFS and uploadd using the IB network. This entry was originally posted on the The Old Toxophilist Site.

    Read the article

  • Django conditional template inheritance

    - by Ed
    I have template that displays object elements with hyperlinks to other parts of my site. I have another function that displays past versions of the same object. In this display, I don't want the hyperlinks. I'm under the assumption that I can't dynamically switch off the hyperlinks, so I've included both versions in the same template. I use an if statement to either display the hyperlinked version or the plain text version. I prefer to keep them in the same template because if I need to change the format of one, it will be easy to apply it to the other right there. The template extends framework.html. Framework has a breadcrumb system and it extends base.html. Base has a simple top menu system. So here's my dilemma. When viewing the standard hyperlink data, I want to see the top menu and the breadcrumbs. But when viewing the past version plain text data, I only want the data, no menu, no breadcrumbs. I'm unsure if this is possible given my current design. I tried having framework inherit the primary template so that I could choose to call either framework (and display the breadcrumbs), or the template itself, thus skipping the breadcrumbs, but I want framework.html available for other templates as well. If framework.html extends a specific template, I lose the ability to display it in other templates. I tried writing an if statement that would display a the top_menu block and the nav_menu block from base.html and framework.html respectively. This would overwrite their blocks and allow me to turn off those elements conditional on the if. Unfortunately, it doesn't appear to be conditional; if the block elements are in the template at all, surrounded by an if or not, I lose the menus. I thought about using {% include %} to pick up the breadcrumbs and a split out top menu. In that case though, I'll have to include it all the time. No more inheritance. Is this the best option given my requirement?

    Read the article

  • Can nested attributes be used in combination with inheritance?

    - by FoxDemon
    I have the following classes: Project Person Person Developer Person Manager In the Project model I have added the following statements: has_and_belongs_to_many :people accepts_nested_attributes_for :people And of course the appropriate statements in the class Person. How can I add an Developer to a Project through the nested_attributes method? The following does not work: @p.people_attributes = [{:name => "Epic Beard Man", :type => "Developer"}] @p.people => [#<Person id: nil, name: "Epic Beard Man", type: nil>] As you can see the type attributes is set to nil instead of Developer.

    Read the article

  • Is there any way to achieve multiple inheritance in php?

    - by Starx
    Lets say I have a parent class class parent { } ..... This parent has three sub class class child1 { } class child2 { } class child3 { } and these child classes have further smaller parts like class child1subpar1 { } class child1subpar2 { public function foo() { echo "hi"; } } class child2subpar1 { } class child2subpar2 { } Now, how to sum this whole up like class child1 extends child1subpar1, child1subpar2 { } class child2 extends child2subpar1, childsubpar1 { } class parent extends child1,child2,child3 { } I need to execute the methods in its inherited classes and do something like this $objparent = new parent; $objparent - foo();

    Read the article

  • JavaScript - Inheritance in Constructors

    - by j0ker
    For a JavaScript project we want to introduce object inheritance to decrease code duplication. However, I cannot quite get it working the way I want and need some help. We use the module pattern. Suppose there is a super element: a.namespace('a.elements.Element'); a.elements.Element = (function() { // public API -- constructor Element = function(properties) { this.id = properties.id; }; // public API -- prototype Element.prototype = { getID: function() { return this.id; } }; return Element; }()); And an element inheriting from this super element: a.namespace('a.elements.SubElement'); a.elements.SubElement = (function() { // public API -- constructor SubElement = function(properties) { // inheritance happens here // ??? this.color = properties.color; this.bogus = this.id + 1; }; // public API -- prototype SubElement.prototype = { getColor: function() { return this.color; } }; return SubElement; }()); You will notice that I'm not quite sure how to implement the inheritance itself. In the constructor I have to be able to pass the parameter to the super object constructor and create a super element that is then used to create the inherited one. I need a (comfortable) possibility to access the properties of the super object within the constructor of the new object. Ideally I could operate on the super object as if it was part of the new object. I also want to be able to create a new SubElement and call getID() on it. What I want to accomplish seems like the traditional class based inheritance. However, I'd like to do it using prototypal inheritance since that's the JavaScript way. Is that even doable? Thanks in advance! EDIT: Fixed usage of private variables as suggested in the comments. EDIT2: Another change of the code: It's important that id is accessible from the constructor of SubElement.

    Read the article

  • C#: Handling Notifications: inheritance, events, or delegates?

    - by James Michael Hare
    Often times as developers we have to design a class where we get notification when certain things happen. In older object-oriented code this would often be implemented by overriding methods -- with events, delegates, and interfaces, however, we have far more elegant options. So, when should you use each of these methods and what are their strengths and weaknesses? Now, for the purposes of this article when I say notification, I'm just talking about ways for a class to let a user know that something has occurred. This can be through any programmatic means such as inheritance, events, delegates, etc. So let's build some context. I'm sitting here thinking about a provider neutral messaging layer for the place I work, and I got to the point where I needed to design the message subscriber which will receive messages from the message bus. Basically, what we want is to be able to create a message listener and have it be called whenever a new message arrives. Now, back before the flood we would have done this via inheritance and an abstract class: 1:  2: // using inheritance - omitting argument null checks and halt logic 3: public abstract class MessageListener 4: { 5: private ISubscriber _subscriber; 6: private bool _isHalted = false; 7: private Thread _messageThread; 8:  9: // assign the subscriber and start the messaging loop 10: public MessageListener(ISubscriber subscriber) 11: { 12: _subscriber = subscriber; 13: _messageThread = new Thread(MessageLoop); 14: _messageThread.Start(); 15: } 16:  17: // user will override this to process their messages 18: protected abstract void OnMessageReceived(Message msg); 19:  20: // handle the looping in the thread 21: private void MessageLoop() 22: { 23: while(!_isHalted) 24: { 25: // as long as processing, wait 1 second for message 26: Message msg = _subscriber.Receive(TimeSpan.FromSeconds(1)); 27: if(msg != null) 28: { 29: OnMessageReceived(msg); 30: } 31: } 32: } 33: ... 34: } It seems so odd to write this kind of code now. Does it feel odd to you? Maybe it's just because I've gotten so used to delegation that I really don't like the feel of this. To me it is akin to saying that if I want to drive my car I need to derive a new instance of it just to put myself in the driver's seat. And yet, unquestionably, five years ago I would have probably written the code as you see above. To me, inheritance is a flawed approach for notifications due to several reasons: Inheritance is one of the HIGHEST forms of coupling. You can't seal the listener class because it depends on sub-classing to work. Because C# does not allow multiple-inheritance, I've spent my one inheritance implementing this class. Every time you need to listen to a bus, you have to derive a class which leads to lots of trivial sub-classes. The act of consuming a message should be a separate responsibility than the act of listening for a message (SRP). Inheritance is such a strong statement (this IS-A that) that it should only be used in building type hierarchies and not for overriding use-specific behaviors and notifications. Chances are, if a class needs to be inherited to be used, it most likely is not designed as well as it could be in today's modern programming languages. So lets look at the other tools available to us for getting notified instead. Here's a few other choices to consider. Have the listener expose a MessageReceived event. Have the listener accept a new IMessageHandler interface instance. Have the listener accept an Action<Message> delegate. Really, all of these are different forms of delegation. Now, .NET events are a bit heavier than the other types of delegates in terms of run-time execution, but they are a great way to allow others using your class to subscribe to your events: 1: // using event - ommiting argument null checks and halt logic 2: public sealed class MessageListener 3: { 4: private ISubscriber _subscriber; 5: private bool _isHalted = false; 6: private Thread _messageThread; 7:  8: // assign the subscriber and start the messaging loop 9: public MessageListener(ISubscriber subscriber) 10: { 11: _subscriber = subscriber; 12: _messageThread = new Thread(MessageLoop); 13: _messageThread.Start(); 14: } 15:  16: // user will override this to process their messages 17: public event Action<Message> MessageReceived; 18:  19: // handle the looping in the thread 20: private void MessageLoop() 21: { 22: while(!_isHalted) 23: { 24: // as long as processing, wait 1 second for message 25: Message msg = _subscriber.Receive(TimeSpan.FromSeconds(1)); 26: if(msg != null && MessageReceived != null) 27: { 28: MessageReceived(msg); 29: } 30: } 31: } 32: } Note, now we can seal the class to avoid changes and the user just needs to provide a message handling method: 1: theListener.MessageReceived += CustomReceiveMethod; However, personally I don't think events hold up as well in this case because events are largely optional. To me, what is the point of a listener if you create one with no event listeners? So in my mind, use events when handling the notification is optional. So how about the delegation via interface? I personally like this method quite a bit. Basically what it does is similar to inheritance method mentioned first, but better because it makes it easy to split the part of the class that doesn't change (the base listener behavior) from the part that does change (the user-specified action after receiving a message). So assuming we had an interface like: 1: public interface IMessageHandler 2: { 3: void OnMessageReceived(Message receivedMessage); 4: } Our listener would look like this: 1: // using delegation via interface - omitting argument null checks and halt logic 2: public sealed class MessageListener 3: { 4: private ISubscriber _subscriber; 5: private IMessageHandler _handler; 6: private bool _isHalted = false; 7: private Thread _messageThread; 8:  9: // assign the subscriber and start the messaging loop 10: public MessageListener(ISubscriber subscriber, IMessageHandler handler) 11: { 12: _subscriber = subscriber; 13: _handler = handler; 14: _messageThread = new Thread(MessageLoop); 15: _messageThread.Start(); 16: } 17:  18: // handle the looping in the thread 19: private void MessageLoop() 20: { 21: while(!_isHalted) 22: { 23: // as long as processing, wait 1 second for message 24: Message msg = _subscriber.Receive(TimeSpan.FromSeconds(1)); 25: if(msg != null) 26: { 27: _handler.OnMessageReceived(msg); 28: } 29: } 30: } 31: } And they would call it by creating a class that implements IMessageHandler and pass that instance into the constructor of the listener. I like that this alleviates the issues of inheritance and essentially forces you to provide a handler (as opposed to events) on construction. Well, this is good, but personally I think we could go one step further. While I like this better than events or inheritance, it still forces you to implement a specific method name. What if that name collides? Furthermore if you have lots of these you end up either with large classes inheriting multiple interfaces to implement one method, or lots of small classes. Also, if you had one class that wanted to manage messages from two different subscribers differently, it wouldn't be able to because the interface can't be overloaded. This brings me to using delegates directly. In general, every time I think about creating an interface for something, and if that interface contains only one method, I start thinking a delegate is a better approach. Now, that said delegates don't accomplish everything an interface can. Obviously having the interface allows you to refer to the classes that implement the interface which can be very handy. In this case, though, really all you want is a method to handle the messages. So let's look at a method delegate: 1: // using delegation via delegate - omitting argument null checks and halt logic 2: public sealed class MessageListener 3: { 4: private ISubscriber _subscriber; 5: private Action<Message> _handler; 6: private bool _isHalted = false; 7: private Thread _messageThread; 8:  9: // assign the subscriber and start the messaging loop 10: public MessageListener(ISubscriber subscriber, Action<Message> handler) 11: { 12: _subscriber = subscriber; 13: _handler = handler; 14: _messageThread = new Thread(MessageLoop); 15: _messageThread.Start(); 16: } 17:  18: // handle the looping in the thread 19: private void MessageLoop() 20: { 21: while(!_isHalted) 22: { 23: // as long as processing, wait 1 second for message 24: Message msg = _subscriber.Receive(TimeSpan.FromSeconds(1)); 25: if(msg != null) 26: { 27: _handler(msg); 28: } 29: } 30: } 31: } Here the MessageListener now takes an Action<Message>.  For those of you unfamiliar with the pre-defined delegate types in .NET, that is a method with the signature: void SomeMethodName(Message). The great thing about delegates is it gives you a lot of power. You could create an anonymous delegate, a lambda, or specify any other method as long as it satisfies the Action<Message> signature. This way, you don't need to define an arbitrary helper class or name the method a specific thing. Incidentally, we could combine both the interface and delegate approach to allow maximum flexibility. Doing this, the user could either pass in a delegate, or specify a delegate interface: 1: // using delegation - give users choice of interface or delegate 2: public sealed class MessageListener 3: { 4: private ISubscriber _subscriber; 5: private Action<Message> _handler; 6: private bool _isHalted = false; 7: private Thread _messageThread; 8:  9: // assign the subscriber and start the messaging loop 10: public MessageListener(ISubscriber subscriber, Action<Message> handler) 11: { 12: _subscriber = subscriber; 13: _handler = handler; 14: _messageThread = new Thread(MessageLoop); 15: _messageThread.Start(); 16: } 17:  18: // passes the interface method as a delegate using method group 19: public MessageListener(ISubscriber subscriber, IMessageHandler handler) 20: : this(subscriber, handler.OnMessageReceived) 21: { 22: } 23:  24: // handle the looping in the thread 25: private void MessageLoop() 26: { 27: while(!_isHalted) 28: { 29: // as long as processing, wait 1 second for message 30: Message msg = _subscriber.Receive(TimeSpan.FromSeconds(1)); 31: if(msg != null) 32: { 33: _handler(msg); 34: } 35: } 36: } 37: } } This is the method I tend to prefer because it allows the user of the class to choose which method works best for them. You may be curious about the actual performance of these different methods. 1: Enter iterations: 2: 1000000 3:  4: Inheritance took 4 ms. 5: Events took 7 ms. 6: Interface delegation took 4 ms. 7: Lambda delegate took 5 ms. Before you get too caught up in the numbers, however, keep in mind that this is performance over over 1,000,000 iterations. Since they are all < 10 ms which boils down to fractions of a micro-second per iteration so really any of them are a fine choice performance wise. As such, I think the choice of what to do really boils down to what you're trying to do. Here's my guidelines: Inheritance should be used only when defining a collection of related types with implementation specific behaviors, it should not be used as a hook for users to add their own functionality. Events should be used when subscription is optional or multi-cast is desired. Interface delegation should be used when you wish to refer to implementing classes by the interface type or if the type requires several methods to be implemented. Delegate method delegation should be used when you only need to provide one method and do not need to refer to implementers by the interface name.

    Read the article

  • Help with my PHP template class

    - by blerh
    I want to separate the output of HTML from my program code in my projects, so I wrote a very simple database class. <?php class Template { private $template; function load($filePath) { if(!$this->template = file_get_contents($filePath)) $this->error('Error: Failed to open <strong>' . $filePath . '</strong>'); } function replace($var, $content) { $this->template = str_replace("{$var}", $content, $this->template); } function display() { echo $this->template; } function error($errorMessage) { die('die() by template class: <strong>' . $errorMessage . '</strong>'); } } ?> The thing I need help with is the display() method. Say for example I use this code: $tplObj = new Template(); $tplObj->load('index.php'); $tplObj->replace('{TITLE}', 'Homepage'); $tplObj->display(); And the index.php file is this: <html> <head> <title>{TITLE}</title> </head> <body> <h1>{TITLE}</h1> <?php if($something) { echo '$something is true'; } else { echo '$something is false'; } ?> </body> </html> I'm just wondering if the PHP code in there would be run? Or would it just be sent to the browser as plaintext? I was using eval() in my template class but I hate that function :P Thanks.

    Read the article

  • Rails: Single Table Inheritance and models subdirectories

    - by Chris
    I have a card-game application which makes use of Single Table Inheritance. I have a class Card, and a database table cards with column type, and a number of subclasses of Card (including class Foo < Card and class Bar < Card, for the sake of argument). As it happens, Foo is a card from the original printing of the game, which Bar is a card from an expansion. In an attempt to rationalise my models, I have created a directory structure like so: app/ + models/ + card.rb + base_game/ + foo.rb + expansion/ + bar.rb And modified environment.rb to contain: Rails::Initializer.run do |config| config.load_paths += Dir["#{RAILS_ROOT}/app/models/**"] end However, when my reads a card from the database, Rails throws the following exception: ActiveRecord::SubclassNotFound (The single-table inheritance mechanism failed to locate the subclass: 'Foo'. This error is raised because the column 'type' is reserved for storing the class in case of inheritance. Please rename this column if you didn't intend it to be used for storing the inheritance class or overwrite Card.inheritance_column to use another column for that information.) Is it possible to make this work, or am I doomed to a flat directory structure?

    Read the article

  • C++ private inheritance and static members/types

    - by WearyMonkey
    I am trying to stop a class from being able to convert its 'this' pointer into a pointer of one of its interfaces. I do this by using private inheritance via a middle proxy class. The problem is that I find private inheritance makes all public static members and types of the base class inaccessible to all classes under the inheriting class in the hierarchy. class Base { public: enum Enum { value }; }; class Middle : private Base { }; class Child : public Middle { public: void Method() { Base::Enum e = Base::value; // doesn't compile BAD! Base* base = this; // doesn't compile GOOD! } }; I've tried this in both VS2008 (the required version) and VS2010, neither work. Can anyone think of a workaround? Or a different approach to stopping the conversion? Also I am curios of the behavior, is it just a side effect of the compiler implementation, or is it by design? If by design, then why? I always thought of private inheritance to mean that nobody knows Middle inherits from Base. However, the exhibited behavior implies private inheritance means a lot more than that, in-fact Child has less access to Base than any namespace not in the class hierarchy!

    Read the article

  • Cheetah pre-compiled template usage quesion

    - by leo
    For performance reason as suggested here, I am studying how to used the pr-compiled template. I edit hello.tmpl in template directory as #attr title = "This is my Template" \${title} Hello \${who}! then issued cheetah-compile.exe .\hello.tmpl and get the hello.py In another python file runner.py , i have !/usr/bin/env python from Cheetah.Template import Template from template import hello def myMethod(): tmpl = hello.hello(searchList=[{'who' : 'world'}]) results = tmpl.respond() print tmpl if name == 'main': myMethod() But the outcome is ${title} Hello ${who}! Debugging for a while, i found that inside hello.py def respond(self, trans=None): ## CHEETAH: main method generated for this template if (not trans and not self._CHEETAH__isBuffering and not callable(self.transaction)): trans = self.transaction # is None unless self.awake() was called if not trans: trans = DummyTransaction() it looks like the trans is None, so it goes to DummyTransaction, what did I miss here? Any suggestions to how to fix it?

    Read the article

  • When a template is rendered in template tag code, MEDIA_URL is not in context

    - by culebrón
    I want to use a template for 2 template tags. In the template, I used {{ MEDIA_URL }} and discovered that MEDIA_URL is not in context as expected. Had to use get_config and pass it manually. Why is the setting not in context, how else can I put it there, or maybe there's a better way that a template tag? (include, etc?) from django.template import Library from apps.annoying.functions import get_config from django.template.loader import render_to_string register = Library() @register.simple_tag def next_in_gallery(photo, gallery): next = photo.get_next_in_gallery(gallery) return make_arrow('right', next) @register.simple_tag def previous_in_gallery(photo, gallery): prev = photo.get_previous_in_gallery(gallery) return make_arrow('left', prev) def make_arrow(direction, object): return render_to_string('myapp/arrow.html', {'direction': direction, 'object': object, 'MEDIA_URL': get_config('MEDIA_URL', '')})

    Read the article

  • Is there a tool for detecting sites using the same template?

    - by KTB
    I often buy webtemplates online, and when I do so I often look at the demos to get some inspiration on how to use the components. But I would love to look at other sites which have already implemented a full website using this template. So I am looking for a tool which searches sites having a similar HTML as the demos (and therefore are probably implementing the template). I am referring to templates which do not have a static text like "Created with Template FooBar by BarFoo" in the footer.

    Read the article

  • Chef: nested data bag data to template file returns "can't convert String into Integer"

    - by Dalho Park
    I'm creating simple test recipe with a template and data bag. What I'm trying to do is creating a config file from data bag that has simple nested information, but I receive error "can't convert String into Integer" Here are my setting file 1) recipe/default.rb data1 = data_bag_item( 'mytest', 'qa' )['test'] data2 = data_bag_item( 'mytest', 'qa' ) template "/opt/env/test.cfg" do source "test.erb" action :create_if_missing mode 0664 owner "root" group "root" variables({ :pepe1 = data1['part.name'], :pepe2 = data2['transport.tcp.ip2'] }) end 2)my data bag named "mytest" $knife data bag show mytest qa id: qa test: part.name: L12 transport.tcp.ip: 111.111.111.111 transport.tcp.port: 9199 transport.tcp.ip2: 222.222.222.222 3)template file test.erb part.name=<%= @pepe1 % transport.tcp.binding=<%= @pepe2 % Error reurns when I run chef-client on my server, [2013-06-24T19:50:38+00:00] DEBUG: filtered backtrace of compile error: /var/chef/cache/cookbooks/config_test/recipes/default.rb:19:in []',/var/chef/cache/cookbooks/config_test/recipes/default.rb:19:inblock in from_file',/var/chef/cache/cookbooks/config_test/recipes/default.rb:12:in from_file' [2013-06-24T19:50:38+00:00] DEBUG: filtered backtrace of compile error: /var/chef/cache/cookbooks/config_test/recipes/default.rb:19:in[]',/var/chef/cache/cookbooks/config_test/recipes/default.rb:19:in block in from_file',/var/chef/cache/cookbooks/config_test/recipes/default.rb:12:infrom_file' [2013-06-24T19:50:38+00:00] DEBUG: backtrace entry for compile error: '/var/chef/cache/cookbooks/config_test/recipes/default.rb:19:in `[]'' [2013-06-24T19:50:38+00:00] DEBUG: Line number of compile error: '19' Recipe Compile Error in /var/chef/cache/cookbooks/config_test/recipes/default.rb TypeError can't convert String into Integer Cookbook Trace: /var/chef/cache/cookbooks/config_test/recipes/default.rb:19:in []' /var/chef/cache/cookbooks/config_test/recipes/default.rb:19:inblock in from_file' /var/chef/cache/cookbooks/config_test/recipes/default.rb:12:in `from_file' Relevant File Content: /var/chef/cache/cookbooks/config_test/recipes/default.rb: 12: template "/opt/env/test.cfg" do 13: source "test.erb" 14: action :create_if_missing 15: mode 0664 16: owner "root" 17: group "root" 18: variables({ 19 :pepe1 = data1['part.name'], 20: :pepe2 = data2['transport.tcp.ip2'] 21: }) 22: end 23: I tried many things and if I comment out "pepe1 = data1['part.name'],", then :pepe2 = data2['transport.tcp.ip2'] works fine. only nested data "part.name" cannot be set to @pepe1. Does anyone knows why I receive the errors? thanks,

    Read the article

  • structures, inheritance and definition

    - by Meloun
    Hi, i need to help with structures, inheritance and definition. //define struct struct tStruct1{ int a; }; //definition tStruct1 struct1{1}; and inheritance struct tStruct2:tStruct1{ int b; }; How can I define it in declaration line? tStruct2 struct2{ ????? }; One more question, how can i use inheritance for structures defined with typedef struct?

    Read the article

  • Backbone inheritance - deep copying

    - by Ed .
    I've seen this question regarding inheritance in Backbone: Backbone.js view inheritance. Useful but doesn't answer my question. The problem I'm experiencing is this: Say I have a class Panel (model in this example); var Panel = Backbone.Model.extend({ defaults : { name : 'my-panel' } }); And then an AdvancedPanel; var AdvancedPanel = Panel.extend({ defaults : { label : 'Click to edit' } }); The following doesn't work: var advancedPanel = new AdvancedPanel(); alert(advancedPanel.get('name')); // Undefined :( JSFiddle here: http://jsfiddle.net/hWmnb/ I guess I can see that I can achieve this myself through some custom extend function that creates a deep copy of the prototype, but this seems like a common thing that people might want from Backbone inheritance, is there a standard way of doing it?

    Read the article

  • Propel Single Table Inheritance Issue

    - by lo_fye
    I have a table called "talk", which is defined as abstract in my schema.xml file. It generates 4 objects (1 per classkey): Comment, Rating, Review, Checkin It also generates TalkPeer, but I couldn't get it to generate the other 4 peers (CommentPeer, RatingPeer, ReviewPeer, CheckinPeer), so I created them by hand, and made them inherit from TalkPeer.php, which inherits from BaseTalkPeer. I then implemented getOMClass() in each of those peers. The problem is that when I do queries using the 4 peers, they return all 4 types of objects. That is, ReviewPeer will return Visits, Ratings, Comments, AND Reviews. Example: $c = new Criteria(); $c->add(RatingPeer::VALUE, 5, Criteria::GREATER_THAN); $positive_ratings = RatingPeer::doSelect($c); This returns all comments, ratings, reviews, & checkins that have a value 5. ReviewPeer should only return Review objects, and can't figure out how to do this. Do I actually have to go through and change all my criteria to manually specify the classkey? That seems a little pointless, since the Peer name already distinct. I don't want to have to customize each Peer. I should be able to customize JUST the TalkPeer, since they all inherit from it... I just can't figure out how. I tried changing doSelectStmt just in TalkPeer so that it automatically adds the CLASSKEY restriction to the Criteria. It almost works, but I get a: Fatal error: Cannot instantiate abstract class Talk in /models/om/BaseTalkPeer.php on line 503. Line 503 is in BaseTalkPeer::populateObjects(), and is the 3rd line below: $cls = TalkPeer::getOMClass($row, 0); $cls = substr('.'.$cls, strrpos('.'.$cls, '.') + 1); $obj = new $cls(); The docs talked about overriding BaseTalkPeer::populateObject(). I have a feeling that's my problem, but even after reading the source code, I still couldn't figure out how to get it to work. Here is what I tried in TalkPeer::doSelectStmt: public static function doSelectStmt(Criteria $criteria, PropelPDO $con = null) { $keys = array('models.Visit'=>1,'models.Comment'=>2,'models.Rating'=>3,'models.Review'=>4); $class_name = self::getOMClass(); if(isset($keys[$class_name])) { //Talk itself is not a returnable type, so we must check $class_key = $keys[$class_name]; $criteria->add(TalkPeer::CLASS_KEY, $class_key); } return parent::doSelectStmt($criteria, $con = null); } Here is an example of my getOMClass method from ReviewPeer: public static function getOMClass() { return self::CLASSNAME_4; //aka 'talk.Review'; } Here is the relevant bit of my schema: <table name="talk" idMethod="native" abstract="true"> <column name="talk_pk" type="INTEGER" required="true" autoIncrement="true" primaryKey="true" /> <column name="class_key" type="INTEGER" required="true" default="" inheritance="single"> <inheritance key="1" class="Visit" extends="models.Talk" /> <inheritance key="2" class="Comment" extends="models.Talk" /> <inheritance key="3" class="Rating" extends="models.Talk" /> <inheritance key="4" class="Review" extends="models.Rating" /> </column> </table> P.S. - No, I can't upgrade from 1.3 to 1.4. There's just too much code that would need to be re-tested

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >