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  • Constructor versus setter injection

    - by Chris
    Hi, I'm currently designing an API where I wish to allow configuration via a variety of methods. One method is via an XML configuration schema and another method is through an API that I wish to play nicely with Spring. My XML schema parsing code was previously hidden and therefore the only concern was for it to work but now I wish to build a public API and I'm quite concerned about best-practice. It seems that many favor javabean type PoJo's with default zero parameter constructors and then setter injection. The problem I am trying to tackle is that some setter methods implementations are dependent on other setter methods being called before them in sequence. I could write anal setters that will tolerate themselves being called in many orders but that will not solve the problem of a user forgetting to set the appropriate setter and therefore the bean being in an incomplete state. The only solution I can think of is to forget about the objects being 'beans' and enforce the required parameters via constructor injection. An example of this is in the default setting of the id of a component based on the id of the parent components. My Interface public interface IMyIdentityInterface { public String getId(); /* A null value should create a unique meaningful default */ public void setId(String id); public IMyIdentityInterface getParent(); public void setParent(IMyIdentityInterface parent); } Base Implementation of interface: public abstract class MyIdentityBaseClass implements IMyIdentityInterface { private String _id; private IMyIdentityInterface _parent; public MyIdentityBaseClass () {} @Override public String getId() { return _id; } /** * If the id is null, then use the id of the parent component * appended with a lower-cased simple name of the current impl * class along with a counter suffix to enforce uniqueness */ @Override public void setId(String id) { if (id == null) { IMyIdentityInterface parent = getParent(); if (parent == null) { // this may be the top level component or it may be that // the user called setId() before setParent(..) } else { _id = Helpers.makeIdFromParent(parent,getClass()); } } else { _id = id; } } @Override public IMyIdentityInterface getParent() { return _parent; } @Override public void setParent(IMyIdentityInterface parent) { _parent = parent; } } Every component in the framework will have a parent except for the top level component. Using the setter type of injection, then the setters will have different behavior based on the order of the calling of the setters. In this case, would you agree, that a constructor taking a reference to the parent is better and dropping the parent setter method from the interface entirely? Is it considered bad practice if I wish to be able to configure these components using an IoC container? Chris

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  • static setter method injection in Spring

    - by vishnu
    Hi, I have following requirement I wanted to pass http:\\localhost:9080\testws.cls value as setter injection through spring configuration file. How can i do this static variable setter injection for WSDL_LOCATION public class Code1 extends javax.xml.ws.Service { private final static URL CODE1_WSDL_LOCATION; static { URL url = null; try { url = new URL("http:\\localhost:9080\testws.cls"); } catch (MalformedURLException e) { e.printStackTrace(); } CODE1_WSDL_LOCATION = url; } public Code1(URL wsdlLocation, QName serviceName) { super(wsdlLocation, serviceName); } public Code1() { super(CODE1_WSDL_LOCATION, new QName("http://tempuri.org", "Code1")); } /** * * @return * returns Code1Soap */ @WebEndpoint(name = "Code1Soap") public Code1Soap getCode1Soap() { return (Code1Soap)super.getPort(new QName("http://tempuri.org", "Code1Soap"), Code1Soap.class); } } Please help me out.

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  • facebook open graph meta property og:type of 'website'. The property 'object-name' requires an object of og:type 'object-name'

    - by chinmayahd
    in cake php 1.3 in view ctp i have follow code: $url = 'http://example.com/exmp/explus/books/view/'.$book['Book']['id']; echo $this->Html->meta(array('property' => 'fb:app_id', 'content' => '*******'),'',array('inline'=>false)); echo $this->Html->meta(array('property' => 'og:type', 'content' => 'book'),'',array('inline'=>false)); echo $this->Html->meta(array('property' => 'og:url', 'content' => $url ),'',array('inline'=>false)); echo $this->Html->meta(array('property' => 'og:title', 'content' => $book['Book']['title']),'',array('inline'=>false)); echo $this->Html->meta(array('property' => 'og:description', 'content' => $book['Book']['title']),'',array('inline'=>false)); $imgurl = '../image/'.$book['Book']['id']; echo $this->Html->meta(array('property' => 'og:image', 'content' => $imgurl ),'',array('inline'=>false)); ?> and it gives the following error when i am posting it' { "error": { "message": "(#3502) Object at URL http://example.com/exmp/explus/books/view/234' has og:type of 'website'. The property 'book' requires an object of og:type 'book'. ", "type": "OAuthException", "code": 3502 } } is any one know how to solve it?

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  • Validation errors prevent the property setter being called

    - by HA
    Hi, I am looking for a simple solution to the following problem: I am using a simple TextBox control with the Text property bound to a property in the code behind. Additionally I am using a validation rule to notify the user of malformed input. ... error display style here ... Now after entering valid data into the TextBox the user can hit a button to send the data. When clicking the button the data from the bound property UserName in the code behind is evaluated and sent. The problem is that a user can enter valid data into the TextBox and this will be set in the property UserName. If the user then decides to change the text in the TextBox and the data becomes invalid, the setter of the property UserName is not called after the failed validation. This means that the last valid data remains in the property UserName, while the TextBox display the invalid data with the error indicator. If the user then clicks on the button to send the data, the last valid data will be sent instead of the current TextBox content. I know I could deactivate the button if the data is invalid and in fact I do, but the method is called in the setter of UserName. And if that is not called after a failed validation the button stays enabled. So the question is: How do I enable calling of the property setter after a failed validation?

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  • WPF Style - value based on another control's property

    - by David Ward
    Is it possible to set the BorderBrush property in a style, to the value of the BorderBrush property of an instance of another control? Something like: <Style x:Key="{x:Type Controls:TimePicker}" TargetType="Controls:TimePicker"> <Setter Property="BorderBrush" Value="[ElementName=txtText Property=BorderBrush]"/> </Style> The reason for this is that I'm using Infragistics controls that have a "Theme" that can be changed and I want my custom control to change border style at the same time.

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  • Dependency Property Set Priority: CodeBehind vs. XAML

    - by LukePet
    When I initialize a control property from code, the binding to the same property defined on XAML don't work. Why? For Example, I set control properties on startup with this statements: myControl.SetValue(UIElement.VisibilityProperty, DefaultProp.Visibility); myControl.SetValue(UIElement.IsEnabledProperty, DefaultProp.IsEnabled); and on xaml I bind the property of myControl in this way: IsEnabled="{Binding Path=IsKeyControlEnabled}" now, when the property "IsKeyControlEnabled" changes to false, myControl remains enabled (because it's initialize with true value). How can I do?

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  • How to access Main Form Public Property WPF

    - by Asim Sajjad
    I have a user control from where I have to call the property of the window which contain the user control how can I access that property. Suppose I have Title Property in my window and I want to access Title property of the window from the user control. Any idea Thanks in advance

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  • SortDescription with custom attached property

    - by Krimson
    Hi, In Xaml I can set a custom attached property using local:TestClass.TestProperty="1" An I can bind to a custom attached property using {Binding Path=(Namespace:[OwnerType].[PropertyName])} {Binding Path=(local:TestClass.TestProperty)} But how do I specify the namespace when I need to use a custom attached property in a SortDescription? I can bind to an attached property using new SortDescription("(Grid.Row)", ListSortDirection.Descending) but here I can't set a namespace anywhere... Best Regards, Jesper

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  • UseEllipses DW Property in PB 10.5

    - by sgian76
    Hello Guys..., I want to use the UseEllipses DW property in PB 10.5. I found that this property is used in PB 11 and after but I don't know if you know something more for this in PB 10.5 or another way to implement it... I 've tried this = dw_master.Modify("comments.EditMask.UseEllipsis=Yes") but an error message is shown that 'UseEllipses' is an unknown property... That's why Iam asking you if you know another way of this property, in order to use it in PB 10.5.2 Thanks in advance !!!

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  • Getting IBindingList Property to sort by

    - by Josh
    I've got a class called DatagridBoundList that implements CollectionBase and IBindingList. The implementation of IBindingList.ApplySort looks like this so far: void IBindingList.ApplySort(PropertyDescriptor property, ListSortDirection direction) { throw new NotSupportedException(); } I'm binding the DatagridBoundList to a DataGridView (winforms). When I reflect over the property parameter, I can't seem to find the name of the actual property that the list needs to be sorted by. What's the trick to finding out the name of the property to sort by?

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  • How do I limit the posible options to be assign to a .net property

    - by carlos
    Hello how can I have like a catalog for a property in .net VB .. I mean if i have Property funcion(ByVal _funcion As Int16) As Int16 Get Return _funcion End Get Set(ByVal value As Int16) _funcion = value End Set End Property I want to be able to assign to this property a limited number of options. Example .. Dim a as trick (the class ) a.funcion = (and get a list of possible attributes) ... Thanks !!!

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  • Extending struts 2 "property" data tag

    - by John B.
    Hi, We are currently developing a project with Struts2. We have a module on which we display a large amount of data on read-only fields from a group of beans via the "property" Struts 2 data tag (i.e. <s:property value="aBeanProperty" /) on a jsp file. In some cases most of the fields might come empty, so a blank is being displayed on screen. Our customer is now requesting us to display default string (i.e. "N/A") whenever a property comes empty, so that it is displayed in place of the blank spaces currently shown. We are looking for a way to achieve this in a clean and maintainable way. The 'property' tag comes with a 'default' attribute on which one can define a default value in cases when the accessed property comes as null. However, most of our properties are empty strings, therefore it does not work in our case. Another solution we are thinking of is to define a base class for all of our beans, and define a util method which will validate if a string is null or empty and then return the default value. Then we would call this method from each bean getter. And yes this would be tiresome and kind of ugly :), therefore we are holding out on this one in case of a better solution. Now, we have in mind a solution which we think would be the best but have not had luck on how implement it. We are planning on extending the 'property' tag some way, defining a new 'default' attribute so that besides working on null properties, it also do so on empty strings ("", " ", etc). Therefore we would only need to replace the original s:property tag with our new custom tag, and the desired result would be achieved without touching java code. Do you have an idea on how to do this? Also, any other clever solution (maybe some sort of design pattern?) on how to default the values of a large amount of property beans are welcome too! (Or maybe, even there might be some tag that does this already in Struts2??) Thanks in advance.

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  • HDFS some datanodes of cluster are suddenly disconnected while reducers are running

    - by user1429825
    I have 8 slave computers and 1 master computer for running Hadoop (ver 0.21) some datanodes of cluster are suddenly disconnected while I was running MapReduce code on 10GB data After all mappers finished and around 80% of reducers was processed, randomly one or more datanode disconned from network. and then the other datanodes start to disappear from network even if I killed the MapReduce job when I found some datanode was disconnected. I've tried to change dfs.datanode.max.xcievers to 4096, turned off fire-walls of all computing node, disabled selinux and increased the number of file open limit to 20000 but they didn't work at all... anyone have a idea to solve this problem? followings are error log from mapreduce 12/06/01 12:31:29 INFO mapreduce.Job: Task Id : attempt_201206011227_0001_r_000006_0, Status : FAILED java.io.IOException: Bad connect ack with firstBadLink as ***.***.***.148:20010 at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.createBlockOutputStream(DFSOutputStream.java:889) at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:820) at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:427) and followings are logs from datanode 2012-06-01 13:01:01,118 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Receiving block blk_-5549263231281364844_3453 src: /*.*.*.147:56205 dest: /*.*.*.142:20010 2012-06-01 13:01:01,136 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: DatanodeRegistration(*.*.*.142:20010, storageID=DS-1534489105-*.*.*.142-20010-1337757934836, infoPort=20075, ipcPort=20020) Starting thread to transfer block blk_-3849519151985279385_5906 to *.*.*.147:20010 2012-06-01 13:01:19,135 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: DatanodeRegistration(*.*.*.142:20010, storageID=DS-1534489105-*.*.*.142-20010-1337757934836, infoPort=20075, ipcPort=20020):Failed to transfer blk_-5797481564121417802_3453 to *.*.*.146:20010 got java.net.ConnectException: > Connection timed out at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:701) at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206) at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:373) at org.apache.hadoop.hdfs.server.datanode.DataNode$DataTransfer.run(DataNode.java:1257) at java.lang.Thread.run(Thread.java:722) 2012-06-01 13:06:20,342 INFO org.apache.hadoop.hdfs.server.datanode.DataBlockScanner: Verification succeeded for blk_6674438989226364081_3453 2012-06-01 13:09:01,781 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: DatanodeRegistration(*.*.*.142:20010, storageID=DS-1534489105-*.*.*.142-20010-1337757934836, infoPort=20075, ipcPort=20020):Failed to transfer blk_-3849519151985279385_5906 to *.*.*.147:20010 got java.net.SocketTimeoutException: 480000 millis timeout while waiting for channel to be ready for write. ch : java.nio.channels.SocketChannel[connected local=/*.*.*.142:60057 remote=/*.*.*.147:20010] at org.apache.hadoop.net.SocketIOWithTimeout.waitForIO(SocketIOWithTimeout.java:246) at org.apache.hadoop.net.SocketOutputStream.waitForWritable(SocketOutputStream.java:164) at org.apache.hadoop.net.SocketOutputStream.transferToFully(SocketOutputStream.java:203) at org.apache.hadoop.hdfs.server.datanode.BlockSender.sendChunks(BlockSender.java:388) at org.apache.hadoop.hdfs.server.datanode.BlockSender.sendBlock(BlockSender.java:476) at org.apache.hadoop.hdfs.server.datanode.DataNode$DataTransfer.run(DataNode.java:1284) at java.lang.Thread.run(Thread.java:722) hdfs-site.xml <configuration> <property> <name>dfs.name.dir</name> <value>/home/hadoop/data/name</value> </property> <property> <name>dfs.data.dir</name> <value>/home/hadoop/data/hdfs1,/home/hadoop/data/hdfs2,/home/hadoop/data/hdfs3,/home/hadoop/data/hdfs4,/home/hadoop/data/hdfs5</value> </property> <property> <name>dfs.replication</name> <value>3</value> </property> <property> <name>dfs.datanode.max.xcievers</name> <value>4096</value> </property> <property> <name>dfs.http.address</name> <value>0.0.0.0:20070</value> <description>50070 The address and the base port where the dfs namenode web ui will listen on. If the port is 0 then the server will start on a free port. </description> </property> <property> <name>dfs.datanode.http.address</name> <value>0.0.0.0:20075</value> <description>50075 The datanode http server address and port. If the port is 0 then the server will start on a free port. </description> </property> <property> <name>dfs.secondary.http.address</name> <value>0.0.0.0:20090</value> <description>50090 The secondary namenode http server address and port. If the port is 0 then the server will start on a free port. </description> </property> <property> <name>dfs.datanode.address</name> <value>0.0.0.0:20010</value> <description>50010 The address where the datanode server will listen to. If the port is 0 then the server will start on a free port. </description> <property> <name>dfs.datanode.ipc.address</name> <value>0.0.0.0:20020</value> <description>50020 The datanode ipc server address and port. If the port is 0 then the server will start on a free port. </description> </property> <property> <name>dfs.datanode.https.address</name> <value>0.0.0.0:20475</value> </property> <property> <name>dfs.https.address</name> <value>0.0.0.0:20470</value> </property> </configuration> mapred-site.xml <configuration> <property> <name>mapred.job.tracker</name> <value>masternode:29001</value> </property> <property> <name>mapred.system.dir</name> <value>/home/hadoop/data/mapreduce/system</value> </property> <property> <name>mapred.local.dir</name> <value>/home/hadoop/data/mapreduce/local</value> </property> <property> <name>mapred.map.tasks</name> <value>32</value> <description> default number of map tasks per job.</description> </property> <property> <name>mapred.tasktracker.map.tasks.maximum</name> <value>4</value> </property> <property> <name>mapred.reduce.tasks</name> <value>8</value> <description> default number of reduce tasks per job.</description> </property> <property> <name>mapred.map.child.java.opts</name> <value>-Xmx2048M</value> </property> <property> <name>io.sort.mb</name> <value>500</value> </property> <property> <name>mapred.task.timeout</name> <value>1800000</value> <!-- 30 minutes --> </property> <property> <name>mapred.job.tracker.http.address</name> <value>0.0.0.0:20030</value> <description> 50030 The job tracker http server address and port the server will listen on. If the port is 0 then the server will start on a free port. </description> </property> <property> <name>mapred.task.tracker.http.address</name> <value>0.0.0.0:20060</value> <description> 50060 </property> </configuration>

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  • Dynamic Type to do away with Reflection

    - by Rick Strahl
    The dynamic type in C# 4.0 is a welcome addition to the language. One thing I’ve been doing a lot with it is to remove explicit Reflection code that’s often necessary when you ‘dynamically’ need to walk and object hierarchy. In the past I’ve had a number of ReflectionUtils that used string based expressions to walk an object hierarchy. With the introduction of dynamic much of the ReflectionUtils code can be removed for cleaner code that runs considerably faster to boot. The old Way - Reflection Here’s a really contrived example, but assume for a second, you’d want to dynamically retrieve a Page.Request.Url.AbsoluteUrl based on a Page instance in an ASP.NET Web Page request. The strongly typed version looks like this: string path = Page.Request.Url.AbsolutePath; Now assume for a second that Page wasn’t available as a strongly typed instance and all you had was an object reference to start with and you couldn’t cast it (right I said this was contrived :-)) If you’re using raw Reflection code to retrieve this you’d end up writing 3 sets of Reflection calls using GetValue(). Here’s some internal code I use to retrieve Property values as part of ReflectionUtils: /// <summary> /// Retrieve a property value from an object dynamically. This is a simple version /// that uses Reflection calls directly. It doesn't support indexers. /// </summary> /// <param name="instance">Object to make the call on</param> /// <param name="property">Property to retrieve</param> /// <returns>Object - cast to proper type</returns> public static object GetProperty(object instance, string property) { return instance.GetType().GetProperty(property, ReflectionUtils.MemberAccess).GetValue(instance, null); } If you want more control over properties and support both fields and properties as well as array indexers a little more work is required: /// <summary> /// Parses Properties and Fields including Array and Collection references. /// Used internally for the 'Ex' Reflection methods. /// </summary> /// <param name="Parent"></param> /// <param name="Property"></param> /// <returns></returns> private static object GetPropertyInternal(object Parent, string Property) { if (Property == "this" || Property == "me") return Parent; object result = null; string pureProperty = Property; string indexes = null; bool isArrayOrCollection = false; // Deal with Array Property if (Property.IndexOf("[") > -1) { pureProperty = Property.Substring(0, Property.IndexOf("[")); indexes = Property.Substring(Property.IndexOf("[")); isArrayOrCollection = true; } // Get the member MemberInfo member = Parent.GetType().GetMember(pureProperty, ReflectionUtils.MemberAccess)[0]; if (member.MemberType == MemberTypes.Property) result = ((PropertyInfo)member).GetValue(Parent, null); else result = ((FieldInfo)member).GetValue(Parent); if (isArrayOrCollection) { indexes = indexes.Replace("[", string.Empty).Replace("]", string.Empty); if (result is Array) { int Index = -1; int.TryParse(indexes, out Index); result = CallMethod(result, "GetValue", Index); } else if (result is ICollection) { if (indexes.StartsWith("\"")) { // String Index indexes = indexes.Trim('\"'); result = CallMethod(result, "get_Item", indexes); } else { // assume numeric index int index = -1; int.TryParse(indexes, out index); result = CallMethod(result, "get_Item", index); } } } return result; } /// <summary> /// Returns a property or field value using a base object and sub members including . syntax. /// For example, you can access: oCustomer.oData.Company with (this,"oCustomer.oData.Company") /// This method also supports indexers in the Property value such as: /// Customer.DataSet.Tables["Customers"].Rows[0] /// </summary> /// <param name="Parent">Parent object to 'start' parsing from. Typically this will be the Page.</param> /// <param name="Property">The property to retrieve. Example: 'Customer.Entity.Company'</param> /// <returns></returns> public static object GetPropertyEx(object Parent, string Property) { Type type = Parent.GetType(); int at = Property.IndexOf("."); if (at < 0) { // Complex parse of the property return GetPropertyInternal(Parent, Property); } // Walk the . syntax - split into current object (Main) and further parsed objects (Subs) string main = Property.Substring(0, at); string subs = Property.Substring(at + 1); // Retrieve the next . section of the property object sub = GetPropertyInternal(Parent, main); // Now go parse the left over sections return GetPropertyEx(sub, subs); } As you can see there’s a fair bit of code involved into retrieving a property or field value reliably especially if you want to support array indexer syntax. This method is then used by a variety of routines to retrieve individual properties including one called GetPropertyEx() which can walk the dot syntax hierarchy easily. Anyway with ReflectionUtils I can  retrieve Page.Request.Url.AbsolutePath using code like this: string url = ReflectionUtils.GetPropertyEx(Page, "Request.Url.AbsolutePath") as string; This works fine, but is bulky to write and of course requires that I use my custom routines. It’s also quite slow as the code in GetPropertyEx does all sorts of string parsing to figure out which members to walk in the hierarchy. Enter dynamic – way easier! .NET 4.0’s dynamic type makes the above really easy. The following code is all that it takes: object objPage = Page; // force to object for contrivance :) dynamic page = objPage; // convert to dynamic from untyped object string scriptUrl = page.Request.Url.AbsolutePath; The dynamic type assignment in the first two lines turns the strongly typed Page object into a dynamic. The first assignment is just part of the contrived example to force the strongly typed Page reference into an untyped value to demonstrate the dynamic member access. The next line then just creates the dynamic type from the Page reference which allows you to access any public properties and methods easily. It also lets you access any child properties as dynamic types so when you look at Intellisense you’ll see something like this when typing Request.: In other words any dynamic value access on an object returns another dynamic object which is what allows the walking of the hierarchy chain. Note also that the result value doesn’t have to be explicitly cast as string in the code above – the compiler is perfectly happy without the cast in this case inferring the target type based on the type being assigned to. The dynamic conversion automatically handles the cast when making the final assignment which is nice making for natural syntnax that looks *exactly* like the fully typed syntax, but is completely dynamic. Note that you can also use indexers in the same natural syntax so the following also works on the dynamic page instance: string scriptUrl = page.Request.ServerVariables["SCRIPT_NAME"]; The dynamic type is going to make a lot of Reflection code go away as it’s simply so much nicer to be able to use natural syntax to write out code that previously required nasty Reflection syntax. Another interesting thing about the dynamic type is that it actually works considerably faster than Reflection. Check out the following methods that check performance: void Reflection() { Stopwatch stop = new Stopwatch(); stop.Start(); for (int i = 0; i < reps; i++) { // string url = ReflectionUtils.GetProperty(Page,"Title") as string;// "Request.Url.AbsolutePath") as string; string url = Page.GetType().GetProperty("Title", ReflectionUtils.MemberAccess).GetValue(Page, null) as string; } stop.Stop(); Response.Write("Reflection: " + stop.ElapsedMilliseconds.ToString()); } void Dynamic() { Stopwatch stop = new Stopwatch(); stop.Start(); dynamic page = Page; for (int i = 0; i < reps; i++) { string url = page.Title; //Request.Url.AbsolutePath; } stop.Stop(); Response.Write("Dynamic: " + stop.ElapsedMilliseconds.ToString()); } The dynamic code runs in 4-5 milliseconds while the Reflection code runs around 200+ milliseconds! There’s a bit of overhead in the first dynamic object call but subsequent calls are blazing fast and performance is actually much better than manual Reflection. Dynamic is definitely a huge win-win situation when you need dynamic access to objects at runtime.© Rick Strahl, West Wind Technologies, 2005-2010Posted in .NET  CSharp  

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  • Creating a dynamic proxy generator with c# – Part 4 – Calling the base method

    - by SeanMcAlinden
    Creating a dynamic proxy generator with c# – Part 1 – Creating the Assembly builder, Module builder and caching mechanism Creating a dynamic proxy generator with c# – Part 2 – Interceptor Design Creating a dynamic proxy generator with c# – Part 3 – Creating the constructors   The plan for calling the base methods from the proxy is to create a private method for each overridden proxy method, this will allow the proxy to use a delegate to simply invoke the private method when required. Quite a few helper classes have been created to make this possible so as usual I would suggest download or viewing the code at http://rapidioc.codeplex.com/. In this post I’m just going to cover the main points for when creating methods. Getting the methods to override The first two notable methods are for getting the methods. private static MethodInfo[] GetMethodsToOverride<TBase>() where TBase : class {     return typeof(TBase).GetMethods().Where(x =>         !methodsToIgnore.Contains(x.Name) &&                              (x.Attributes & MethodAttributes.Final) == 0)         .ToArray(); } private static StringCollection GetMethodsToIgnore() {     return new StringCollection()     {         "ToString",         "GetHashCode",         "Equals",         "GetType"     }; } The GetMethodsToIgnore method string collection contains an array of methods that I don’t want to override. In the GetMethodsToOverride method, you’ll notice a binary AND which is basically saying not to include any methods marked final i.e. not virtual. Creating the MethodInfo for calling the base method This method should hopefully be fairly easy to follow, it’s only function is to create a MethodInfo which points to the correct base method, and with the correct parameters. private static MethodInfo CreateCallBaseMethodInfo<TBase>(MethodInfo method) where TBase : class {     Type[] baseMethodParameterTypes = ParameterHelper.GetParameterTypes(method, method.GetParameters());       return typeof(TBase).GetMethod(        method.Name,        BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic,        null,        baseMethodParameterTypes,        null     ); }   /// <summary> /// Get the parameter types. /// </summary> /// <param name="method">The method.</param> /// <param name="parameters">The parameters.</param> public static Type[] GetParameterTypes(MethodInfo method, ParameterInfo[] parameters) {     Type[] parameterTypesList = Type.EmptyTypes;       if (parameters.Length > 0)     {         parameterTypesList = CreateParametersList(parameters);     }     return parameterTypesList; }   Creating the new private methods for calling the base method The following method outline how I’ve created the private methods for calling the base class method. private static MethodBuilder CreateCallBaseMethodBuilder(TypeBuilder typeBuilder, MethodInfo method) {     string callBaseSuffix = "GetBaseMethod";       if (method.IsGenericMethod || method.IsGenericMethodDefinition)     {                         return MethodHelper.SetUpGenericMethod             (                 typeBuilder,                 method,                 method.Name + callBaseSuffix,                 MethodAttributes.Private | MethodAttributes.HideBySig             );     }     else     {         return MethodHelper.SetupNonGenericMethod             (                 typeBuilder,                 method,                 method.Name + callBaseSuffix,                 MethodAttributes.Private | MethodAttributes.HideBySig             );     } } The CreateCallBaseMethodBuilder is the entry point method for creating the call base method. I’ve added a suffix to the base classes method name to keep it unique. Non Generic Methods Creating a non generic method is fairly simple public static MethodBuilder SetupNonGenericMethod(     TypeBuilder typeBuilder,     MethodInfo method,     string methodName,     MethodAttributes methodAttributes) {     ParameterInfo[] parameters = method.GetParameters();       Type[] parameterTypes = ParameterHelper.GetParameterTypes(method, parameters);       Type returnType = method.ReturnType;       MethodBuilder methodBuilder = CreateMethodBuilder         (             typeBuilder,             method,             methodName,             methodAttributes,             parameterTypes,             returnType         );       ParameterHelper.SetUpParameters(parameterTypes, parameters, methodBuilder);       return methodBuilder; }   private static MethodBuilder CreateMethodBuilder (     TypeBuilder typeBuilder,     MethodInfo method,     string methodName,     MethodAttributes methodAttributes,     Type[] parameterTypes,     Type returnType ) { MethodBuilder methodBuilder = typeBuilder.DefineMethod(methodName, methodAttributes, returnType, parameterTypes); return methodBuilder; } As you can see, you simply have to declare a method builder, get the parameter types, and set the method attributes you want.   Generic Methods Creating generic methods takes a little bit more work. /// <summary> /// Sets up generic method. /// </summary> /// <param name="typeBuilder">The type builder.</param> /// <param name="method">The method.</param> /// <param name="methodName">Name of the method.</param> /// <param name="methodAttributes">The method attributes.</param> public static MethodBuilder SetUpGenericMethod     (         TypeBuilder typeBuilder,         MethodInfo method,         string methodName,         MethodAttributes methodAttributes     ) {     ParameterInfo[] parameters = method.GetParameters();       Type[] parameterTypes = ParameterHelper.GetParameterTypes(method, parameters);       MethodBuilder methodBuilder = typeBuilder.DefineMethod(methodName,         methodAttributes);       Type[] genericArguments = method.GetGenericArguments();       GenericTypeParameterBuilder[] genericTypeParameters =         GetGenericTypeParameters(methodBuilder, genericArguments);       ParameterHelper.SetUpParameterConstraints(parameterTypes, genericTypeParameters);       SetUpReturnType(method, methodBuilder, genericTypeParameters);       if (method.IsGenericMethod)     {         methodBuilder.MakeGenericMethod(genericArguments);     }       ParameterHelper.SetUpParameters(parameterTypes, parameters, methodBuilder);       return methodBuilder; }   private static GenericTypeParameterBuilder[] GetGenericTypeParameters     (         MethodBuilder methodBuilder,         Type[] genericArguments     ) {     return methodBuilder.DefineGenericParameters(GenericsHelper.GetArgumentNames(genericArguments)); }   private static void SetUpReturnType(MethodInfo method, MethodBuilder methodBuilder, GenericTypeParameterBuilder[] genericTypeParameters) {     if (method.IsGenericMethodDefinition)     {         SetUpGenericDefinitionReturnType(method, methodBuilder, genericTypeParameters);     }     else     {         methodBuilder.SetReturnType(method.ReturnType);     } }   private static void SetUpGenericDefinitionReturnType(MethodInfo method, MethodBuilder methodBuilder, GenericTypeParameterBuilder[] genericTypeParameters) {     if (method.ReturnType == null)     {         methodBuilder.SetReturnType(typeof(void));     }     else if (method.ReturnType.IsGenericType)     {         methodBuilder.SetReturnType(genericTypeParameters.Where             (x => x.Name == method.ReturnType.Name).First());     }     else     {         methodBuilder.SetReturnType(method.ReturnType);     }             } Ok, there are a few helper methods missing, basically there is way to much code to put in this post, take a look at the code at http://rapidioc.codeplex.com/ to follow it through completely. Basically though, when dealing with generics there is extra work to do in terms of getting the generic argument types setting up any generic parameter constraints setting up the return type setting up the method as a generic All of the information is easy to get via reflection from the MethodInfo.   Emitting the new private method Emitting the new private method is relatively simple as it’s only function is calling the base method and returning a result if the return type is not void. ILGenerator il = privateMethodBuilder.GetILGenerator();   EmitCallBaseMethod(method, callBaseMethod, il);   private static void EmitCallBaseMethod(MethodInfo method, MethodInfo callBaseMethod, ILGenerator il) {     int privateParameterCount = method.GetParameters().Length;       il.Emit(OpCodes.Ldarg_0);       if (privateParameterCount > 0)     {         for (int arg = 0; arg < privateParameterCount; arg++)         {             il.Emit(OpCodes.Ldarg_S, arg + 1);         }     }       il.Emit(OpCodes.Call, callBaseMethod);       il.Emit(OpCodes.Ret); } So in the main method building method, an ILGenerator is created from the method builder. The ILGenerator performs the following actions: Load the class (this) onto the stack using the hidden argument Ldarg_0. Create an argument on the stack for each of the method parameters (starting at 1 because 0 is the hidden argument) Call the base method using the Opcodes.Call code and the MethodInfo we created earlier. Call return on the method   Conclusion Now we have the private methods prepared for calling the base method, we have reached the last of the relatively easy part of the proxy building. Hopefully, it hasn’t been too hard to follow so far, there is a lot of code so I haven’t been able to post it all so please check it out at http://rapidioc.codeplex.com/. The next section should be up fairly soon, it’s going to cover creating the delegates for calling the private methods created in this post.   Kind Regards, Sean.

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  • Creating a dynamic proxy generator with c# – Part 3 – Creating the constructors

    - by SeanMcAlinden
    Creating a dynamic proxy generator with c# – Part 1 – Creating the Assembly builder, Module builder and caching mechanism Creating a dynamic proxy generator with c# – Part 2 – Interceptor Design For the latest code go to http://rapidioc.codeplex.com/ When building our proxy type, the first thing we need to do is build the constructors. There needs to be a corresponding constructor for each constructor on the passed in base type. We also want to create a field to store the interceptors and construct this list within each constructor. So assuming the passed in base type is a User<int, IRepository> class, were looking to generate constructor code like the following:   Default Constructor public User`2_RapidDynamicBaseProxy() {     this.interceptors = new List<IInterceptor<User<int, IRepository>>>();     DefaultInterceptor<User<int, IRepository>> item = new DefaultInterceptor<User<int, IRepository>>();     this.interceptors.Add(item); }     Parameterised Constructor public User`2_RapidDynamicBaseProxy(IRepository repository1) : base(repository1) {     this.interceptors = new List<IInterceptor<User<int, IRepository>>>();     DefaultInterceptor<User<int, IRepository>> item = new DefaultInterceptor<User<int, IRepository>>();     this.interceptors.Add(item); }   As you can see, we first populate a field on the class with a new list of the passed in base type. Construct our DefaultInterceptor class. Add the DefaultInterceptor instance to our interceptor collection. Although this seems like a relatively small task, there is a fair amount of work require to get this going. Instead of going through every line of code – please download the latest from http://rapidioc.codeplex.com/ and debug through. In this post I’m going to concentrate on explaining how it works. TypeBuilder The TypeBuilder class is the main class used to create the type. You instantiate a new TypeBuilder using the assembly module we created in part 1. /// <summary> /// Creates a type builder. /// </summary> /// <typeparam name="TBase">The type of the base class to be proxied.</typeparam> public static TypeBuilder CreateTypeBuilder<TBase>() where TBase : class {     TypeBuilder typeBuilder = DynamicModuleCache.Get.DefineType         (             CreateTypeName<TBase>(),             TypeAttributes.Class | TypeAttributes.Public,             typeof(TBase),             new Type[] { typeof(IProxy) }         );       if (typeof(TBase).IsGenericType)     {         GenericsHelper.MakeGenericType(typeof(TBase), typeBuilder);     }       return typeBuilder; }   private static string CreateTypeName<TBase>() where TBase : class {     return string.Format("{0}_RapidDynamicBaseProxy", typeof(TBase).Name); } As you can see, I’ve create a new public class derived from TBase which also implements my IProxy interface, this is used later for adding interceptors. If the base type is generic, the following GenericsHelper.MakeGenericType method is called. GenericsHelper using System; using System.Reflection.Emit; namespace Rapid.DynamicProxy.Types.Helpers {     /// <summary>     /// Helper class for generic types and methods.     /// </summary>     internal static class GenericsHelper     {         /// <summary>         /// Makes the typeBuilder a generic.         /// </summary>         /// <param name="concrete">The concrete.</param>         /// <param name="typeBuilder">The type builder.</param>         public static void MakeGenericType(Type baseType, TypeBuilder typeBuilder)         {             Type[] genericArguments = baseType.GetGenericArguments();               string[] genericArgumentNames = GetArgumentNames(genericArguments);               GenericTypeParameterBuilder[] genericTypeParameterBuilder                 = typeBuilder.DefineGenericParameters(genericArgumentNames);               typeBuilder.MakeGenericType(genericTypeParameterBuilder);         }           /// <summary>         /// Gets the argument names from an array of generic argument types.         /// </summary>         /// <param name="genericArguments">The generic arguments.</param>         public static string[] GetArgumentNames(Type[] genericArguments)         {             string[] genericArgumentNames = new string[genericArguments.Length];               for (int i = 0; i < genericArguments.Length; i++)             {                 genericArgumentNames[i] = genericArguments[i].Name;             }               return genericArgumentNames;         }     } }       As you can see, I’m getting all of the generic argument types and names, creating a GenericTypeParameterBuilder and then using the typeBuilder to make the new type generic. InterceptorsField The interceptors field will store a List<IInterceptor<TBase>>. Fields are simple made using the FieldBuilder class. The following code demonstrates how to create the interceptor field. FieldBuilder interceptorsField = typeBuilder.DefineField(     "interceptors",     typeof(System.Collections.Generic.List<>).MakeGenericType(typeof(IInterceptor<TBase>)),       FieldAttributes.Private     ); The field will now exist with the new Type although it currently has no data – we’ll deal with this in the constructor. Add method for interceptorsField To enable us to add to the interceptorsField list, we are going to utilise the Add method that already exists within the System.Collections.Generic.List class. We still however have to create the methodInfo necessary to call the add method. This can be done similar to the following: Add Interceptor Field MethodInfo addInterceptor = typeof(List<>)     .MakeGenericType(new Type[] { typeof(IInterceptor<>).MakeGenericType(typeof(TBase)) })     .GetMethod     (        "Add",        BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic,        null,        new Type[] { typeof(IInterceptor<>).MakeGenericType(typeof(TBase)) },        null     ); So we’ve create a List<IInterceptor<TBase>> type, then using the type created a method info called Add which accepts an IInterceptor<TBase>. Now in our constructor we can use this to call this.interceptors.Add(// interceptor); Building the Constructors This will be the first hard-core part of the proxy building process so I’m going to show the class and then try to explain what everything is doing. For a clear view, download the source from http://rapidioc.codeplex.com/, go to the test project and debug through the constructor building section. Anyway, here it is: DynamicConstructorBuilder using System; using System.Collections.Generic; using System.Reflection; using System.Reflection.Emit; using Rapid.DynamicProxy.Interception; using Rapid.DynamicProxy.Types.Helpers; namespace Rapid.DynamicProxy.Types.Constructors {     /// <summary>     /// Class for creating the proxy constructors.     /// </summary>     internal static class DynamicConstructorBuilder     {         /// <summary>         /// Builds the constructors.         /// </summary>         /// <typeparam name="TBase">The base type.</typeparam>         /// <param name="typeBuilder">The type builder.</param>         /// <param name="interceptorsField">The interceptors field.</param>         public static void BuildConstructors<TBase>             (                 TypeBuilder typeBuilder,                 FieldBuilder interceptorsField,                 MethodInfo addInterceptor             )             where TBase : class         {             ConstructorInfo interceptorsFieldConstructor = CreateInterceptorsFieldConstructor<TBase>();               ConstructorInfo defaultInterceptorConstructor = CreateDefaultInterceptorConstructor<TBase>();               ConstructorInfo[] constructors = typeof(TBase).GetConstructors();               foreach (ConstructorInfo constructorInfo in constructors)             {                 CreateConstructor<TBase>                     (                         typeBuilder,                         interceptorsField,                         interceptorsFieldConstructor,                         defaultInterceptorConstructor,                         addInterceptor,                         constructorInfo                     );             }         }           #region Private Methods           private static void CreateConstructor<TBase>             (                 TypeBuilder typeBuilder,                 FieldBuilder interceptorsField,                 ConstructorInfo interceptorsFieldConstructor,                 ConstructorInfo defaultInterceptorConstructor,                 MethodInfo AddDefaultInterceptor,                 ConstructorInfo constructorInfo             ) where TBase : class         {             Type[] parameterTypes = GetParameterTypes(constructorInfo);               ConstructorBuilder constructorBuilder = CreateConstructorBuilder(typeBuilder, parameterTypes);               ILGenerator cIL = constructorBuilder.GetILGenerator();               LocalBuilder defaultInterceptorMethodVariable =                 cIL.DeclareLocal(typeof(DefaultInterceptor<>).MakeGenericType(typeof(TBase)));               ConstructInterceptorsField(interceptorsField, interceptorsFieldConstructor, cIL);               ConstructDefaultInterceptor(defaultInterceptorConstructor, cIL, defaultInterceptorMethodVariable);               AddDefaultInterceptorToInterceptorsList                 (                     interceptorsField,                     AddDefaultInterceptor,                     cIL,                     defaultInterceptorMethodVariable                 );               CreateConstructor(constructorInfo, parameterTypes, cIL);         }           private static void CreateConstructor(ConstructorInfo constructorInfo, Type[] parameterTypes, ILGenerator cIL)         {             cIL.Emit(OpCodes.Ldarg_0);               if (parameterTypes.Length > 0)             {                 LoadParameterTypes(parameterTypes, cIL);             }               cIL.Emit(OpCodes.Call, constructorInfo);             cIL.Emit(OpCodes.Ret);         }           private static void LoadParameterTypes(Type[] parameterTypes, ILGenerator cIL)         {             for (int i = 1; i <= parameterTypes.Length; i++)             {                 cIL.Emit(OpCodes.Ldarg_S, i);             }         }           private static void AddDefaultInterceptorToInterceptorsList             (                 FieldBuilder interceptorsField,                 MethodInfo AddDefaultInterceptor,                 ILGenerator cIL,                 LocalBuilder defaultInterceptorMethodVariable             )         {             cIL.Emit(OpCodes.Ldarg_0);             cIL.Emit(OpCodes.Ldfld, interceptorsField);             cIL.Emit(OpCodes.Ldloc, defaultInterceptorMethodVariable);             cIL.Emit(OpCodes.Callvirt, AddDefaultInterceptor);         }           private static void ConstructDefaultInterceptor             (                 ConstructorInfo defaultInterceptorConstructor,                 ILGenerator cIL,                 LocalBuilder defaultInterceptorMethodVariable             )         {             cIL.Emit(OpCodes.Newobj, defaultInterceptorConstructor);             cIL.Emit(OpCodes.Stloc, defaultInterceptorMethodVariable);         }           private static void ConstructInterceptorsField             (                 FieldBuilder interceptorsField,                 ConstructorInfo interceptorsFieldConstructor,                 ILGenerator cIL             )         {             cIL.Emit(OpCodes.Ldarg_0);             cIL.Emit(OpCodes.Newobj, interceptorsFieldConstructor);             cIL.Emit(OpCodes.Stfld, interceptorsField);         }           private static ConstructorBuilder CreateConstructorBuilder(TypeBuilder typeBuilder, Type[] parameterTypes)         {             return typeBuilder.DefineConstructor                 (                     MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.RTSpecialName                     | MethodAttributes.HideBySig, CallingConventions.Standard, parameterTypes                 );         }           private static Type[] GetParameterTypes(ConstructorInfo constructorInfo)         {             ParameterInfo[] parameterInfoArray = constructorInfo.GetParameters();               Type[] parameterTypes = new Type[parameterInfoArray.Length];               for (int p = 0; p < parameterInfoArray.Length; p++)             {                 parameterTypes[p] = parameterInfoArray[p].ParameterType;             }               return parameterTypes;         }           private static ConstructorInfo CreateInterceptorsFieldConstructor<TBase>() where TBase : class         {             return ConstructorHelper.CreateGenericConstructorInfo                 (                     typeof(List<>),                     new Type[] { typeof(IInterceptor<TBase>) },                     BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic                 );         }           private static ConstructorInfo CreateDefaultInterceptorConstructor<TBase>() where TBase : class         {             return ConstructorHelper.CreateGenericConstructorInfo                 (                     typeof(DefaultInterceptor<>),                     new Type[] { typeof(TBase) },                     BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic                 );         }           #endregion     } } So, the first two tasks within the class should be fairly clear, we are creating a ConstructorInfo for the interceptorField list and a ConstructorInfo for the DefaultConstructor, this is for instantiating them in each contructor. We then using Reflection get an array of all of the constructors in the base class, we then loop through the array and create a corresponding proxy contructor. Hopefully, the code is fairly easy to follow other than some new types and the dreaded Opcodes. ConstructorBuilder This class defines a new constructor on the type. ILGenerator The ILGenerator allows the use of Reflection.Emit to create the method body. LocalBuilder The local builder allows the storage of data in local variables within a method, in this case it’s the constructed DefaultInterceptor. Constructing the interceptors field The first bit of IL you’ll come across as you follow through the code is the following private method used for constructing the field list of interceptors. private static void ConstructInterceptorsField             (                 FieldBuilder interceptorsField,                 ConstructorInfo interceptorsFieldConstructor,                 ILGenerator cIL             )         {             cIL.Emit(OpCodes.Ldarg_0);             cIL.Emit(OpCodes.Newobj, interceptorsFieldConstructor);             cIL.Emit(OpCodes.Stfld, interceptorsField);         } The first thing to know about generating code using IL is that you are using a stack, if you want to use something, you need to push it up the stack etc. etc. OpCodes.ldArg_0 This opcode is a really interesting one, basically each method has a hidden first argument of the containing class instance (apart from static classes), constructors are no different. This is the reason you can use syntax like this.myField. So back to the method, as we want to instantiate the List in the interceptorsField, first we need to load the class instance onto the stack, we then load the new object (new List<TBase>) and finally we store it in the interceptorsField. Hopefully, that should follow easily enough in the method. In each constructor you would now have this.interceptors = new List<User<int, IRepository>>(); Constructing and storing the DefaultInterceptor The next bit of code we need to create is the constructed DefaultInterceptor. Firstly, we create a local builder to store the constructed type. Create a local builder LocalBuilder defaultInterceptorMethodVariable =     cIL.DeclareLocal(typeof(DefaultInterceptor<>).MakeGenericType(typeof(TBase))); Once our local builder is ready, we then need to construct the DefaultInterceptor<TBase> and store it in the variable. Connstruct DefaultInterceptor private static void ConstructDefaultInterceptor     (         ConstructorInfo defaultInterceptorConstructor,         ILGenerator cIL,         LocalBuilder defaultInterceptorMethodVariable     ) {     cIL.Emit(OpCodes.Newobj, defaultInterceptorConstructor);     cIL.Emit(OpCodes.Stloc, defaultInterceptorMethodVariable); } As you can see, using the ConstructorInfo named defaultInterceptorConstructor, we load the new object onto the stack. Then using the store local opcode (OpCodes.Stloc), we store the new object in the local builder named defaultInterceptorMethodVariable. Add the constructed DefaultInterceptor to the interceptors field collection Using the add method created earlier in this post, we are going to add the new DefaultInterceptor object to the interceptors field collection. Add Default Interceptor private static void AddDefaultInterceptorToInterceptorsList     (         FieldBuilder interceptorsField,         MethodInfo AddDefaultInterceptor,         ILGenerator cIL,         LocalBuilder defaultInterceptorMethodVariable     ) {     cIL.Emit(OpCodes.Ldarg_0);     cIL.Emit(OpCodes.Ldfld, interceptorsField);     cIL.Emit(OpCodes.Ldloc, defaultInterceptorMethodVariable);     cIL.Emit(OpCodes.Callvirt, AddDefaultInterceptor); } So, here’s whats going on. The class instance is first loaded onto the stack using the load argument at index 0 opcode (OpCodes.Ldarg_0) (remember the first arg is the hidden class instance). The interceptorsField is then loaded onto the stack using the load field opcode (OpCodes.Ldfld). We then load the DefaultInterceptor object we stored locally using the load local opcode (OpCodes.Ldloc). Then finally we call the AddDefaultInterceptor method using the call virtual opcode (Opcodes.Callvirt). Completing the constructor The last thing we need to do is complete the constructor. Complete the constructor private static void CreateConstructor(ConstructorInfo constructorInfo, Type[] parameterTypes, ILGenerator cIL)         {             cIL.Emit(OpCodes.Ldarg_0);               if (parameterTypes.Length > 0)             {                 LoadParameterTypes(parameterTypes, cIL);             }               cIL.Emit(OpCodes.Call, constructorInfo);             cIL.Emit(OpCodes.Ret);         }           private static void LoadParameterTypes(Type[] parameterTypes, ILGenerator cIL)         {             for (int i = 1; i <= parameterTypes.Length; i++)             {                 cIL.Emit(OpCodes.Ldarg_S, i);             }         } So, the first thing we do again is load the class instance using the load argument at index 0 opcode (OpCodes.Ldarg_0). We then load each parameter using OpCode.Ldarg_S, this opcode allows us to specify an index position for each argument. We then setup calling the base constructor using OpCodes.Call and the base constructors ConstructorInfo. Finally, all methods are required to return, even when they have a void return. As there are no values on the stack after the OpCodes.Call line, we can safely call the OpCode.Ret to give the constructor a void return. If there was a value, we would have to pop the value of the stack before calling return otherwise, the method would try and return a value. Conclusion This was a slightly hardcore post but hopefully it hasn’t been too hard to follow. The main thing is that a number of the really useful opcodes have been used and now the dynamic proxy is capable of being constructed. If you download the code and debug through the tests at http://rapidioc.codeplex.com/, you’ll be able to create proxies at this point, they cannon do anything in terms of interception but you can happily run the tests, call base methods and properties and also take a look at the created assembly in Reflector. Hope this is useful. The next post should be up soon, it will be covering creating the private methods for calling the base class methods and properties. Kind Regards, Sean.

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  • Connect ViewModel and View using Unity

    - by brainbox
    In this post i want to describe the approach of connecting View and ViewModel which I'm using in my last project.The main idea is to do it during resolve inside of unity container. It can be achived using InjectionFactory introduced in Unity 2.0 public static class MVVMUnityExtensions{    public static void RegisterView<TView, TViewModel>(this IUnityContainer container) where TView : FrameworkElement    {        container.RegisterView<TView, TView, TViewModel>();    }    public static void RegisterView<TViewFrom, TViewTo, TViewModel>(this IUnityContainer container)        where TViewTo : FrameworkElement, TViewFrom    {        container.RegisterType<TViewFrom>(new InjectionFactory(            c =>            {                var model = c.Resolve<TViewModel>();                var view = Activator.CreateInstance<TViewTo>();                view.DataContext = model;                return view;            }         ));    }}}And here is the sample how it could be used:var unityContainer = new UnityContainer();unityContainer.RegisterView<IFooView, FooView, FooViewModel>();IFooView view = unityContainer.Resolve<IFooView>(); // view with injected viewmodel in its datacontextPlease tell me your prefered way to connect viewmodel and view.

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  • C# Multiple Property Sort

    - by Ben Griswold
    As you can see in the snippet below, sorting is easy with Linq.  Simply provide your OrderBy criteria and you’re done.  If you want a secondary sort field, add a ThenBy expression to the chain.  Want a third level sort?  Just add ThenBy along with another sort expression. var projects = new List<Project>     {         new Project {Description = "A", ProjectStatusTypeId = 1},         new Project {Description = "B", ProjectStatusTypeId = 3},         new Project {Description = "C", ProjectStatusTypeId = 3},         new Project {Description = "C", ProjectStatusTypeId = 2},         new Project {Description = "E", ProjectStatusTypeId = 1},         new Project {Description = "A", ProjectStatusTypeId = 2},         new Project {Description = "C", ProjectStatusTypeId = 4},         new Project {Description = "A", ProjectStatusTypeId = 3}     };   projects = projects     .OrderBy(x => x.Description)     .ThenBy(x => x.ProjectStatusTypeId)     .ToList();   foreach (var project in projects) {     Console.Out.WriteLine("{0} {1}", project.Description,         project.ProjectStatusTypeId); } Linq offers a great sort solution most of the time, but what if you want or need to do it the old fashioned way? projects.Sort ((x, y) =>         Comparer<String>.Default             .Compare(x.Description, y.Description) != 0 ?         Comparer<String>.Default             .Compare(x.Description, y.Description) :         Comparer<Int32>.Default             .Compare(x.ProjectStatusTypeId, y.ProjectStatusTypeId));   foreach (var project in projects) {     Console.Out.WriteLine("{0} {1}", project.Description,         project.ProjectStatusTypeId); } It’s not that bad, right? Just for fun, let add some additional logic to our sort.  Let’s say we wanted our secondary sort to be based on the name associated with the ProjectStatusTypeId.  projects.Sort((x, y) =>        Comparer<String>.Default             .Compare(x.Description, y.Description) != 0 ?        Comparer<String>.Default             .Compare(x.Description, y.Description) :        Comparer<String>.Default             .Compare(GetProjectStatusTypeName(x.ProjectStatusTypeId),                 GetProjectStatusTypeName(y.ProjectStatusTypeId)));   foreach (var project in projects) {     Console.Out.WriteLine("{0} {1}", project.Description,         GetProjectStatusTypeName(project.ProjectStatusTypeId)); } The comparer will now consider the result of the GetProjectStatusTypeName and order the list accordingly.  Of course, you can take this same approach with Linq as well.

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  • Configure EnableTransaction and IsolationLevel property in Business Rules for Dynamic Send Port

    - by Vishal
    Why do you want to add these properties to the BRE..??                 There is a lot of performance issue when using WCF adapters with Dynamic Send Port. Please check the below link for more info.   http://blogs.msdn.com/mdoctor/archive/2009/12/18/performance-tip-when-using-wcf-custom-with-dynamic-send-ports-and-custom-bindings-on-biztalk-server-2009.aspx?CommentPosted=true#commentmessage     So if you are using ESB Toolkit 2.0 in your solution and you do not want to move towards static adapte then you can add the below line in your SetEndpointConfig value for BRE.                 BindingType=xyzAdapterBinding&EnableTransaction=true&IsolationLevel=ReadCommited&BindingConfiguration=<bindingname=”xyzAdapterBinding" />   The IsolationLevel values can be: Serializable RepeatableRead ReadCommited ReadUncommited Snapshot Chaos   Below are few Business Rules Composer Screenshots.

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  • Simplified INotifyPropertyChanged Implementation with WeakReference Support and Typed Property Acces

    - by Daniel Cazzulino
    I've grown a bit tired of implementing INotifyPropertyChanged. I've tried ways to improve it before (like this "ViewModel" custom tool which even generates strong-typed event accessors). But my fellow Clarius teammate Mariano thought it was overkill and didn't like that tool much. He mentioned an alternative approach also, which I didn't like too much because it relied on the consumer changing his typical interaction with the object events, but also because it has a substantial design flaw that causes handlers not to be called at all after a garbage collection happens. A very simple unit test will showcase this bug....Read full article

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  • Renault under threat from industrial espionage, intellectual property the target

    - by Simon Thorpe
    Last year we saw news of both General Motors and Ford losing a significant amount of valuable information to competitors overseas. Within weeks of the turn of 2011 we see the European car manufacturer, Renault, also suffering. In a recent news report, French Industry Minister Eric Besson warned the country was facing "economic war" and referenced a serious case of espionage which concerns information pertaining to the development of electric cars. Renault senior vice president Christian Husson told the AFP news agency that the people concerned were in a "particularly strategic position" in the company. An investigation had uncovered a "body of evidence which shows that the actions of these three colleagues were contrary to the ethics of Renault and knowingly and deliberately placed at risk the company's assets", Mr Husson said. A source told Reuters on Wednesday the company is worried its flagship electric vehicle program, in which Renault with its partner Nissan is investing 4 billion euros ($5.3 billion), might be threatened. This casts a shadow over the estimated losses of Ford ($50 million) and General Motors ($40 million). One executive in the corporate intelligence-gathering industry, who spoke on condition of anonymity, said: "It's really difficult to say it's a case of corporate espionage ... It can be carelessness." He cited a hypothetical example of an enthusiastic employee giving away too much information about his job on an online forum. While information has always been passed and leaked, inadvertently or on purpose, the rise of the Internet and social media means corporate spies or careless employees are now more likely to be found out, he added. We are seeing more and more examples of where companies like these need to invest in technologies such as Oracle IRM to ensure such important information can be kept under control. It isn't just the recent release of information into the public domain via the Wikileaks website that is of concern, but also the increasing threats of industrial espionage in cases such as these. Information rights management doesn't totally remove the threat, but abilities to control documents no matter where they exist certainly increases the capabilities significantly. Every single time someone opens a sealed document the IRM system audits the activity. This makes identifying a potential source for a leak much easier when you have an absolute record of every person who's had access to the documents. Oracle IRM can also help with accidental or careless loss. Often people use very sensitive information all the time and forget the importance of handling it correctly. With the ability to protect the information from screen shots and prevent people copy and pasting document information into social networks and other, unsecured documents, Oracle IRM brings a totally new level of information security that would have a significant impact on reducing the risk these organizations face of losing their most valuable information.

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  • Test interface implementation

    - by Michael
    I have a interface in our code base that I would like to be able to mock out for unit testing. I am writing a test implementation to allow the individual tests to be able to override the specific methods they are concerned with rather than implementing every method. I've run into a quandary over how the test implementation should behave if the test fails to override a method used by the method under test. Should I return a "non-value" (0, null) in the test implementation or throw a UnsupportedOperationException to explicitly fail the test?

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  • The Database as Intellectual Property

    - by Jonathan Kehayias
    Every so often, a question shows up on the forums in the form of, “How do I prevent anyone from accessing my database schema, including local administrators and sysadmins in SQL Server?”  I usually laugh a little shake my head when I read a question like this because it demonstrates an complete lack of understanding of the power an administrator has over SQL Server.  The simple answer is this: If you don’t want your database schema to ever be accessed or known, don’t distribute your database....(read more)

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