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  • Identifying NHibernate proxy classes

    - by Marc Gravell
    I'm not an NHibernate user; I write a serialization utility library. A user has logged a feature-request that I should handle NHibernate proxy classes, treating them the same as the actual type. At the moment my code is treating them as unexpected inheritance, and throwing an exception. The code won't know in advance about NHibernate (including no reference, but I'm not aftaid of reflection ;-p) Is there a robust / guaranteed way of detecting such proxy types? Apparently DataContractSerializer handles this fine, so I'm hoping it is something pretty simple. Perhaps some interface or [attribute] decoration. Also, during deserialization; at the moment I would be creating the original type (not the NHibernate type). Is this fine for persistence purposes? Or is the proxy type required? If the latter; what is required to create an instance of the proxy type?

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  • What does it mean to treat data as an asset?

    What does it mean to treat data as an asset? When considering this concept, we must define what data is and how it can be considered an asset. Data can easily be defined as a collection of stored truths that are open to interpretation and manipulation.  Expanding on this definition, data can be viewed as a set of captured facts, measurements, and ideas used to make decisions. Furthermore, InvestorsWords.com defines asset as any item of economic value owned by an individual or corporation. Now let’s apply this definition of asset to our definition of data, and ask the following question. Can facts, measurements and ideas be items that are of economic value owned by an individual or corporation? The obvious answer is yes; data can be bought and sold like commodities or analyzed to make smarter business decisions.  We can look at the economic value of data in one of two ways. First, data can be sold as a commodity that can take the form of goods like eBooks, Training, Music, Movies, and so on. Customers are willing to pay to gain access to this data for their consumption. This directly implies that there is an economic value for data in the form of a commodity because customers see a value in obtaining it.  Secondly data can be used in making smarter business decisions that allow for companies to become more profitable and/or reduce their potential for risk in regards to how they operate.  In the past I have worked at companies where we had to analyze previous sales activities in conjunction with current activities to determine how the company was preforming for the quarter.  In addition trends can be formulated based on existing data that allow companies to forecast data so that they can make strategic business decisions based sound forecasted data. Companies that truly value their data are constantly trying to grow and upgrade their data and supporting applications because it is the life blood of a company. If we look at an eBook retailer for example, imagine if they lost all of their data. They would be in essence forced out of business because they would have nothing to sell. In turn, if we look at a company that was using data to facilitate better decision making processes and they lost all of their data then they could be losing potential revenue and/ or increasing the company’s losses by making important business decisions virtually in the dark compared to when they were made on solid data.

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  • mootools many buttons with one function to handle

    - by Roby
    i want to create a button list like <form id="form"> <input type="button" value="skip"> <input type="button" value="continue"> <input type="button" value="bla"> <input type="button" value="blubb"> </form> and want to post this via a request to a php script witch should get somethink like button "skip" was clicked. but i dont want to make a function for every button. one function for all button. i think it should work with the mootools relay function. $('form').addEvent('click:relay(type=button)', function(){ alert(this.value); }); or somethink like this ? :-/ hopefully someone could help me

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  • Wrangling Control of HTTP Headers in ASP.NET

    - by Andrew Burgess
    I'm working with ASP.NET MVC3, and I'm trying to get absolute control over my headers because a client application that I'm working with expects a very specific content type. What I'm finding when using Fiddler to examine the HTTP traffic is that the text encoding is being returned as part of the header. For example, the client is expecting application/appname in the Content-Type header, but the server is returning application/appname; charset=utf-8. I think the client is using a strict comparison for checking the type, so I want to be able to specify exactly what is emitted in the headers. Right now I have a custom ActionResult in which I clear the headers and then specify only the content type, but the encoding still seems to be added on. How can I remove the encoding from the Content-Type header?

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  • Basis of definitions

    - by Yttrill
    Let us suppose we have a set of functions which characterise something: in the OO world methods characterising a type. In mathematics these are propositions and we have two kinds: axioms and lemmas. Axioms are assumptions, lemmas are easily derived from them. In C++ axioms are pure virtual functions. Here's the problem: there's more than one way to axiomatise a system. Given a set of propositions or methods, a subset of the propositions which is necessary and sufficient to derive all the others is called a basis. So too, for methods or functions, we have a desired set which must be defined, and typically every one has one or more definitions in terms of the others, and we require the programmer to provide instance definitions which are sufficient to allow all the others to be defined, and, if there is an overspecification, then it is consistent. Let me give an example (in Felix, Haskell code would be similar): class Eq[t] { virtual fun ==(x:t,y:t):bool => eq(x,y); virtual fun eq(x:t, y:t)=> x == y; virtual fun != (x:t,y:t):bool => not (x == y); axiom reflex(x:t): x == x; axiom sym(x:t, y:t): (x == y) == (y == x); axiom trans(x:t, y:t, z:t): implies(x == y and y == z, x == z); } Here it is clear: the programmer must define either == or eq or both. If both are defined, the definitions must be equivalent. Failing to define one doesn't cause a compiler error, it causes an infinite loop at run time. Defining both inequivalently doesn't cause an error either, it is just inconsistent. Note the axioms specified constrain the semantics of any definition. Given a definition of == either directly or via a definition of eq, then != is defined automatically, although the programmer might replace the default with something more efficient, clearly such an overspecification has to be consistent. Please note, == could also be defined in terms of !=, but we didn't do that. A characterisation of a partial or total order is more complex. It is much more demanding since there is a combinatorial explosion of possible bases. There is an reason to desire overspecification: performance. There also another reason: choice and convenience. So here, there are several questions: one is how to check semantics are obeyed and I am not looking for an answer here (way too hard!). The other question is: How can we specify, and check, that an instance provides at least a basis? And a much harder question: how can we provide several default definitions which depend on the basis chosen?

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  • Java generics: What is the compiler's issue here? ("no unique maximal instance")

    - by Epaga
    I have the following methods: public <T> T fromJson( Reader jsonData, Class<T> clazz ) { return fromJson( jsonData, (Type)clazz ); } public <T> T fromJson( Reader jsonData, Type clazz ) { ... } The compiler is saying about the first method: type parameters of <T>T cannot be determined; no unique maximal instance exists for type variable T with upper bounds T,java.lang.Object return fromJson( jsonData, (Type)clazz ); ^ What is the problem?

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  • Unable to boot: Missing Operating system

    - by Vivek S Panicker
    i had installed Ubuntu 11.10 along with the another Ubuntu 11.10 which already installed in my netbook. Later I formatted the partition I newly installed. Next time when I boot it went to Grub Rescue menu. I boot my system again with Ubuntu USB stick, Then I installed Boot repair package in USB and restored MBR and GRUB menu in hard disk. Now when I am restarting, I am getting a message Missing operating system, press any key to continue. Can somebody help me on this? Below is the output for sudo fdisk -l omitting empty partition (7) Disk /dev/sda: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00058a60 Device Boot Start End Blocks Id System /dev/sda1 * 2048 204072287 102035120 83 Linux /dev/sda2 204072958 312580095 54253569 5 Extended /dev/sda5 310507520 312580095 1036288 82 Linux swap / Solaris /dev/sda6 308432896 310503423 1035264 82 Linux swap / Solaris Partition table entries are not in disk order Disk /dev/sdb: 4006 MB, 4006608896 bytes 124 heads, 62 sectors/track, 1017 cylinders, total 7825408 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0004d3df Device Boot Start End Blocks Id System /dev/sdb1 * 62 7818695 3909317 b W95 FAT32 Below is the output for sudo blkid /dev/loop0: TYPE="squashfs" /dev/loop1: LABEL="casper-rw" UUID="533defb1-f073-254a-b46f-7ca0ac1f4e0c" TYPE="ext2" /dev/sda1: LABEL="Ubuntu" UUID="6a141040-3ba8-457a-9de5-ad06e6057084" TYPE="ext4" /dev/sda5: UUID="3a7f62d6-9c65-4d12-a3b6-5d62b9710f7d" TYPE="swap" /dev/sda6: UUID="274da115-cec2-4418-a1af-88fe921e3670" TYPE="swap" /dev/sdb1: LABEL="PENDRIVE" UUID="EC22-6BE4" TYPE="vfat" File /boot/grub/grub.cfg # # DO NOT EDIT THIS FILE # # It is automatically generated by grub-mkconfig using templates # from /etc/grub.d and settings from /etc/default/grub # ### BEGIN /etc/grub.d/00_header ### if [ -s $prefix/grubenv ]; then set have_grubenv=true load_env fi set default="0" if [ "${prev_saved_entry}" ]; then set saved_entry="${prev_saved_entry}" save_env saved_entry set prev_saved_entry= save_env prev_saved_entry set boot_once=true fi function savedefault { if [ -z "${boot_once}" ]; then saved_entry="${chosen}" save_env saved_entry fi } function recordfail { set recordfail=1 if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi } function load_video { insmod vbe insmod vga insmod video_bochs insmod video_cirrus } insmod part_msdos insmod ext2 set root='(hd0,msdos1)' search --no-floppy --fs-uuid --set=root 6a141040-3ba8-457a-9de5-ad06e6057084 if loadfont /usr/share/grub/unicode.pf2 ; then set gfxmode=auto load_video insmod gfxterm insmod part_msdos insmod ext2 set root='(hd0,msdos1)' search --no-floppy --fs-uuid --set=root 6a141040-3ba8-457a-9de5-ad06e6057084 set locale_dir=($root)/boot/grub/locale set lang=en_US insmod gettext fi terminal_output gfxterm if [ "${recordfail}" = 1 ]; then set timeout=10 else set timeout=10 fi ### END /etc/grub.d/00_header ### ### BEGIN /etc/grub.d/05_debian_theme ### set menu_color_normal=white/black set menu_color_highlight=black/light-gray if background_color 44,0,30; then clear fi ### END /etc/grub.d/05_debian_theme ### ### BEGIN /etc/grub.d/10_linux ### if [ ${recordfail} != 1 ]; then if [ -e ${prefix}/gfxblacklist.txt ]; then if hwmatch ${prefix}/gfxblacklist.txt 3; then if [ ${match} = 0 ]; then set linux_gfx_mode=keep else set linux_gfx_mode=text fi else set linux_gfx_mode=text fi else set linux_gfx_mode=keep fi else set linux_gfx_mode=text fi export linux_gfx_mode if [ "$linux_gfx_mode" != "text" ]; then load_video; fi menuentry 'Ubuntu, with Linux 3.0.0-12-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail set gfxpayload=$linux_gfx_mode insmod gzio insmod part_msdos insmod ext2 set root='(hd0,msdos1)' search --no-floppy --fs-uuid --set=root 6a141040-3ba8-457a-9de5-ad06e6057084 linux /boot/vmlinuz-3.0.0-12-generic root=UUID=6a141040-3ba8-457a-9de5-ad06e6057084 ro quiet splash vt.handoff=7 initrd /boot/initrd.img-3.0.0-12-generic } menuentry 'Ubuntu, with Linux 3.0.0-12-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod gzio insmod part_msdos insmod ext2 set root='(hd0,msdos1)' search --no-floppy --fs-uuid --set=root 6a141040-3ba8-457a-9de5-ad06e6057084 echo 'Loading Linux 3.0.0-12-generic ...' linux /boot/vmlinuz-3.0.0-12-generic root=UUID=6a141040-3ba8-457a-9de5-ad06e6057084 ro recovery nomodeset echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.0.0-12-generic } ### END /etc/grub.d/10_linux ### ### BEGIN /etc/grub.d/20_linux_xen ### ### END /etc/grub.d/20_linux_xen ### ### BEGIN /etc/grub.d/20_memtest86+ ### menuentry "Memory test (memtest86+)" { insmod part_msdos insmod ext2 set root='(hd0,msdos1)' search --no-floppy --fs-uuid --set=root 6a141040-3ba8-457a-9de5-ad06e6057084 linux16 /boot/memtest86+.bin } menuentry "Memory test (memtest86+, serial console 115200)" { insmod part_msdos insmod ext2 set root='(hd0,msdos1)' search --no-floppy --fs-uuid --set=root 6a141040-3ba8-457a-9de5-ad06e6057084 linux16 /boot/memtest86+.bin console=ttyS0,115200n8 } ### END /etc/grub.d/20_memtest86+ ### ### BEGIN /etc/grub.d/30_os-prober ### ### END /etc/grub.d/30_os-prober ### ### BEGIN /etc/grub.d/40_custom ### # This file provides an easy way to add custom menu entries. Simply type the # menu entries you want to add after this comment. Be careful not to change # the 'exec tail' line above. ### END /etc/grub.d/40_custom ### ### BEGIN /etc/grub.d/41_custom ### if [ -f $prefix/custom.cfg ]; then source $prefix/custom.cfg; fi ### END /etc/grub.d/41_custom ###

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  • Unidirectional OneToMany in Doctrine 2

    - by darja
    I have two Doctrine entities looking like that: /** * @Entity * @Table(name = "Locales") */ class Locale { /** * @Id @Column(type="integer") * @GeneratedValue(strategy="IDENTITY") */ private $id; /** @Column(length=2, name="Name", type="string") */ private $code; } /** * @Entity * @Table(name = "localized") */ class LocalizedStrings { /** * @Id @Column(type="integer") * @GeneratedValue(strategy="IDENTITY") */ private $id; /** @Column(name="Locale", type="integer") */ private $locale; /** @Column(name="SomeText", type="string", length=300) */ private $someText; } I'd like to create reference between these entities. LocalizedStrings needs reference to Locale but Locale doesn't need reference to LocalizedStrings. How to write such mapping via Doctrine 2?

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  • Do you believe it's a good idea for Software Engineers to have to work as Quality Assurance Engineers for some period of time?

    - by Macy Abbey
    I believe it is. Why? I've encountered many Software Engineers who believe they are somehow superior to QA engineers. I think it may help quench this belief if they do the job of a QA engineer for some time, and realize that it is a unique and valuable skill-set of its own. The better a Software Engineer is at testing their own programs, the less cost in time their code incurs when making its way through the rest of the software development life-cycle. The more time a Software Engineer spends thinking about how a program can break, the more often they are to consider these cases as they are developing them, thus reducing bugs in the end product. A Software Engineer's definition of "complete" is always interesting...if they have spent time as a QA engineer maybe this definition will more closely match the designer of the software's. What do you all think?

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  • Moving DataSets through BizTalk

    - by EltonStoneman
    [Source: http://geekswithblogs.net/EltonStoneman] Yuck. But sometimes you have to, so here are a couple of things to bear in mind: Schemas Point a codegen tool at a WCF endpoint which exposes a DataSet and it will generate an XSD which describes the DataSet like this: <xs:elementminOccurs="0"name="GetDataSetResult"nillable="true">  <xs:complexType>     <xs:annotation>       <xs:appinfo>         <ActualTypeName="DataSet"                     Namespace="http://schemas.datacontract.org/2004/07/System.Data"                     xmlns="http://schemas.microsoft.com/2003/10/Serialization/" />       </xs:appinfo>     </xs:annotation>     <xs:sequence>       <xs:elementref="xs:schema" />       <xs:any />     </xs:sequence>  </xs:complexType> </xs:element>  In a serialized instance, the element of type xs:schema contains a full schema which describes the structure of the DataSet – tables, columns etc. The second element, of type xs:any, contains the actual content of the DataSet, expressed as DiffGrams: <GetDataSetResult>  <xs:schemaid="NewDataSet"xmlns:xs="http://www.w3.org/2001/XMLSchema"xmlns=""xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">     <xs:elementname="NewDataSet"msdata:IsDataSet="true"msdata:UseCurrentLocale="true">       <xs:complexType>         <xs:choiceminOccurs="0"maxOccurs="unbounded">           <xs:elementname="Table1">             <xs:complexType>               <xs:sequence>                 <xs:elementname="Id"type="xs:string"minOccurs="0" />                 <xs:elementname="Name"type="xs:string"minOccurs="0" />                 <xs:elementname="Date"type="xs:string"minOccurs="0" />               </xs:sequence>             </xs:complexType>           </xs:element>         </xs:choice>       </xs:complexType>     </xs:element>  </xs:schema>  <diffgr:diffgramxmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1"xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">     <NewDataSetxmlns="">       <Table1diffgr:id="Table11"msdata:rowOrder="0"diffgr:hasChanges="inserted">         <Id>377fdf8d-cfd1-4975-a167-2ddb41265def</Id>         <Name>157bc287-f09b-435f-a81f-2a3b23aff8c4</Name>         <Date>a5d78d83-6c9a-46ca-8277-f2be8d4658bf</Date>       </Table1>     </NewDataSet>  </diffgr:diffgram> </GetDataSetResult> Put the XSD into a BizTalk schema and it will fail to compile, giving you error: The 'http://www.w3.org/2001/XMLSchema:schema' element is not declared. You should be able to work around that, but I've had no luck in BizTalk Server 2006 R2 – instead you can safely change that xs:schema element to be another xs:any type: <xs:elementminOccurs="0"name="GetDataSetResult"nillable="true">  <xs:complexType>     <xs:sequence>       <xs:any />       <xs:any />     </xs:sequence>  </xs:complexType> </xs:element>  (This snippet omits the annotation, but you can leave it in the schema). For an XML instance to pass validation through the schema, you'll also need to flag the any attributes so they can contain any namespace and skip validation:  <xs:elementminOccurs="0"name="GetDataSetResult"nillable="true">  <xs:complexType>     <xs:sequence>       <xs:anynamespace="##any"processContents="skip" />       <xs:anynamespace="##any"processContents="skip" />     </xs:sequence>  </xs:complexType> </xs:element>  You should now have a compiling schema which can be successfully tested against a serialised DataSet. Transforms If you're mapping a DataSet element between schemas, you'll need to use the Mass Copy Functoid to populate the target node from the contents of both the xs:any type elements on the source node: This should give you a compiled map which you can test against a serialized instance. And if you have a .NET consumer on the other side of the mapped BizTalk output, it will correctly deserialize the response into a DataSet.

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  • Getting My Head Around Immutability

    - by Michael Mangold
    I'm new to object-oriented programming, and one concept that has been taking me a while to grasp is immutability. I think the light bulb went off last night but I want to verify: When I come across statements that an immutable object cannot be changed, I'm puzzled because I can, for instance, do the following: NSString *myName = @"Bob"; myName = @"Mike"; There, I just changed myName, of immutable type NSString. My problem is that the word, "object" can refer to the physical object in memory, or the abstraction, "myName." The former definition applies to the concept of immutability. As for the variable, a more clear (to me) definition of immutability is that the value of an immutable object can only be changed by also changing its location in memory, i.e. its reference (also known as its pointer). Is this correct, or am I still lost in the woods?

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  • Subscribing to a ObservableCollection via reflection

    - by Julian Lettner
    How can I subscribe to a ObservableCollection<??> without knowing the element type of the collection? Is there a way to do this without too many 'magic strings'? This is a question for the .NET version 3.5. I think 4.0 would make my life much easier, right? Type type = collection.GetType(); if(type.IsGenericType && type.GetGenericTypeDefinition() == typeof(ObservableCollection<>)) { // I cannot cast the collection here ObservableCollection<object> x = collection; } Thanks for your time.

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  • Looking into the JQuery Cycle Plugin

    - by nikolaosk
    I have been using JQuery for a couple of years now and it has helped me to solve many problems on the client. You can find all my posts about JQuery in this link. In this post I will be providing you with a hands-on example on the JQuery Cycle Plugin.I have been using extensively this plugin in my websites.You can rotate a series of images using various transitions with this plugin.It is a slideshow type of experience. I will be writing more posts regarding the most commonly used JQuery Plugins.  In this hands-on example I will be using Expression Web 4.0.This application is not a free application. You can use any HTML editor you like.You can use Visual Studio 2012 Express edition. You can download it here.  You can download this plugin from this link I launch Expression Web 4.0 and then I type the following HTML markup (I am using HTML 5) <!DOCTYPE html><html lang="en">  <head>    <title>Liverpool Legends</title>        <meta http-equiv="Content-Type" content="text/html;charset=utf-8" >            <script type="text/javascript" src="jquery-1.8.3.min.js"> </script>     <script type="text/javascript" src="jquery.cycle.all.js"></script>              <script type="text/javascript">        $(function() {            $('#main').cycle({ fx: 'fade'});        });    </script>       </head>  <body>    <header>        <h1>Liverpool Legends</h1>    </header>        <div id="main">                   <img src="championsofeurope.jpg" alt="Champions of Europe">                        <img src="steven_gerrard.jpg" alt="Steven Gerrard">                        <img src="ynwa.jpg" alt="You will never walk alone">                       </div>            <footer>        <p>All Rights Reserved</p>      </footer>     </body>  </html> This is a very simple markup. I have added three photos (make sure you use your own when trying this example)I have added references to the JQuery library (current version is 1.8.3) and the JQuery Cycle Plugin. Then I have added 3 images in the main div element.The Javascript code that makes it all happen follows.  <script type="text/javascript">        $(function() {            $('#main').cycle({ fx: 'fade'});        });    </script>  It couldn't be any simpler than that. I view my simple in Internet Explorer 10 and it works as expected. I have this series of images transitioning one after the other using the "fade" effect. I have tested this simple solution in all major browsers and it works fine.We can have a different transition effect by changing the JS code. Have a look at the code below       <script type="text/javascript">        $(function() {            $('#main').cycle({                     fx: 'cover',        speed: 500,        timeout: 2000                        });        });    </script>   We set the speed to 500 milliseconds, that is the speed we want to have for the ‘cover’ transition.The timeout is set to two seconds which is the time the photo will show until the next transition will take place.We can customise this plugin further but this is a short introduction to the plugin.Hope it helps!!!

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  • Public property List needs to Concat 2 types with inheritance

    - by Bernard
    I have 2 lists: one of type A and one of type Aa. type Aa is inherited from type A. So: List<A> listA = new List<A>(); List<Aa> listAa = new List<Aa>(); with class Aa : A I have: public property Lists<A> { get { List<A> newList = new List<A>(); //return concat of both lists foreach(List l in listA) { newList.Add(l); } foreach(List l in listAa) { newList.Add(l); } } Can I somehow use Concat instead of the foreach loop? i.e. get { return listA.Concat(listAa); } // this doesn't work And secondly, how do I do the set part of the property? set { //figure out the type of variable value and put into appropriate list? }

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  • Calling a COM+ Component remotely using C#

    - by Arturo Caballero
    Hello, I have a little COM+ component as a service on a remote server. I´m trying to execute a method of this component using: Type type = Type.GetTypeFromProgID("ComPlusTest.ComTestClass",serverName); // Create Service Object service = Activator.CreateInstance(type); // Execute Method String result = service.GetType().InvokeMember("LaunchPackage", BindingFlags.InvokeMethod, null, parameters, null).ToString(); The type is returned as null. What is the best way to do this?? The server is Windows 2003 Enterprise, the service is a .NET component wraped as COM+ (I know that I don´t have to do it that way, but the purpose is to itegrate a legacy App with a .NET component) The purpose of this is just to test that the .NET COM+ Component works. Thanks in advance!

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  • Limit JavaScript and CSS files on ASP.NET MVC 2 Master Page based on Model and View content

    - by Zack Peterson
    I want to include certain .js and .css files only on pages that need them. For example, my EditorTemplate DateTime.ascx needs files anytimec.js and anytimec.css. That template is applied whenever I use either the EditorFor or EditorForModel helper methods in a view for a model with a DateTime type value. I've put this condition into the <head> section of my master page. It checks for a DateTime type property in the ModelMetadata. <% if (this.ViewData.ModelMetadata.Properties.Any(p => p.ModelType == typeof(DateTime))) { %> <link href="../../Content/anytimec.css" rel="stylesheet" type="text/css" /> <script src="../../Scripts/anytimec.js" type="text/javascript"></script> <% } %> This has two problems: Fails if I have nested child models of type DateTime Unnecessarily triggered by views without EditorFor or EditorForModel methods (example: DisplayForModel) How can I improve this technique?

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  • Passing a parameter so that it cannot be changed – C#

    - by nmarun
    I read this requirement of not allowing a user to change the value of a property passed as a parameter to a method. In C++, as far as I could recall (it’s been over 10 yrs, so I had to refresh memory), you can pass ‘const’ to a function parameter and this ensures that the parameter cannot be changed inside the scope of the function. There’s no such direct way of doing this in C#, but that does not mean it cannot be done!! Ok, so this ‘not-so-direct’ technique depends on the type of the parameter – a simple property or a collection. Parameter as a simple property: This is quite easy (and you might have guessed it already). Bulent Ozkir clearly explains how this can be done here. Parameter as a collection property: Obviously the above does not work if the parameter is a collection of some type. Let’s dig-in. Suppose I need to create a collection of type KeyTitle as defined below. 1: public class KeyTitle 2: { 3: public int Key { get; set; } 4: public string Title { get; set; } 5: } My class is declared as below: 1: public class Class1 2: { 3: public Class1() 4: { 5: MyKeyTitleList = new List<KeyTitle>(); 6: } 7: 8: public List<KeyTitle> MyKeyTitleList { get; set; } 9: public ReadOnlyCollection<KeyTitle> ReadonlyKeyTitleCollection 10: { 11: // .AsReadOnly creates a ReadOnlyCollection<> type 12: get { return MyKeyTitleList.AsReadOnly(); } 13: } 14: } See the .AsReadOnly() method used in the second property? As MSDN says it: “Returns a read-only IList<T> wrapper for the current collection.” Knowing this, I can implement my code as: 1: public static void Main() 2: { 3: Class1 class1 = new Class1(); 4: class1.MyKeyTitleList.Add(new KeyTitle { Key = 1, Title = "abc" }); 5: class1.MyKeyTitleList.Add(new KeyTitle { Key = 2, Title = "def" }); 6: class1.MyKeyTitleList.Add(new KeyTitle { Key = 3, Title = "ghi" }); 7: class1.MyKeyTitleList.Add(new KeyTitle { Key = 4, Title = "jkl" }); 8:  9: TryToModifyCollection(class1.MyKeyTitleList.AsReadOnly()); 10:  11: Console.ReadLine(); 12: } 13:  14: private static void TryToModifyCollection(ReadOnlyCollection<KeyTitle> readOnlyCollection) 15: { 16: // can only read 17: for (int i = 0; i < readOnlyCollection.Count; i++) 18: { 19: Console.WriteLine("{0} - {1}", readOnlyCollection[i].Key, readOnlyCollection[i].Title); 20: } 21: // Add() - not allowed 22: // even the indexer does not have a setter 23: } The output is as expected: The below image shows two things. In the first line, I’ve tried to access an element in my read-only collection through an indexer. It shows that the ReadOnlyCollection<> does not have a setter on the indexer. The second line tells that there’s no ‘Add()’ method for this type of collection. The capture below shows there’s no ‘Remove()’ method either, there-by eliminating all ways of modifying a collection. Mission accomplished… right? Now, even if you have a collection of different type, all you need to do is to somehow cast (used loosely) it to a List<> and then do a .AsReadOnly() to get a ReadOnlyCollection of your custom collection type. As an example, if you have an IDictionary<int, string>, you can create a List<T> of this type with a wrapper class (KeyTitle in our case). 1: public IDictionary<int, string> MyDictionary { get; set; } 2:  3: public ReadOnlyCollection<KeyTitle> ReadonlyDictionary 4: { 5: get 6: { 7: return (from item in MyDictionary 8: select new KeyTitle 9: { 10: Key = item.Key, 11: Title = item.Value, 12: }).ToList().AsReadOnly(); 13: } 14: } Cool huh? Just one thing you need to know about the .AsReadOnly() method is that the only way to modify your ReadOnlyCollection<> is to modify the original collection. So doing: 1: public static void Main() 2: { 3: Class1 class1 = new Class1(); 4: class1.MyKeyTitleList.Add(new KeyTitle { Key = 1, Title = "abc" }); 5: class1.MyKeyTitleList.Add(new KeyTitle { Key = 2, Title = "def" }); 6: class1.MyKeyTitleList.Add(new KeyTitle { Key = 3, Title = "ghi" }); 7: class1.MyKeyTitleList.Add(new KeyTitle { Key = 4, Title = "jkl" }); 8: TryToModifyCollection(class1.MyKeyTitleList.AsReadOnly()); 9:  10: Console.WriteLine(); 11:  12: class1.MyKeyTitleList.Add(new KeyTitle { Key = 5, Title = "mno" }); 13: class1.MyKeyTitleList[2] = new KeyTitle{Key = 3, Title = "GHI"}; 14: TryToModifyCollection(class1.MyKeyTitleList.AsReadOnly()); 15:  16: Console.ReadLine(); 17: } Gives me the output of: See that the second element’s Title is changed to upper-case and the fifth element also gets displayed even though we’re still looping through the same ReadOnlyCollection<KeyTitle>. Verdict: Now you know of a way to implement ‘Method(const param1)’ in your code!

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  • NDepend Evaluation: Part 3

    - by Anthony Trudeau
    NDepend is a Visual Studio add-in designed for intense code analysis with the goal of high code quality. NDepend uses a number of metrics and aggregates the data in pleasing static and active visual reports. My evaluation of NDepend will be broken up into several different parts. In the first part of the evaluation I looked at installing the add-in.  And in the last part I went over my first impressions including an overview of the features.  In this installment I provide a little more detail on a few of the features that I really like. Dependency Matrix The dependency matrix is one of the rich visual components provided with NDepend.  At a glance it lets you know where you have coupling problems including cycles.  It does this with number indicating the weight of the dependency and a color-coding that indicates the nature of the dependency. Green and blue cells are direct dependencies (with the difference being whether the relationship is from row-to-column or column-to-row).  Black cells are the ones that you really want to know about.  These indicate that you have a cycle.  That is, type A refers to type B and type B also refers to Type A. But, that’s not the end of the story.  A handy pop-up appears when you hover over the cell in question.  It explains the color, the dependency, and provides several interesting links that will teach you more than you want to know about the dependency. You can double-click the problem cells to explode the dependency.  That will show the dependencies on a method-by-method basis allowing you to more easily target and fix the problem.  When you’re done you can click the back button on the toolbar. Dependency Graph The dependency graph is another component provided.  It’s complementary to the dependency matrix, but it isn’t as easy to identify dependency issues using the window. On a positive note, it does provide more information than the matrix. My biggest issue with the dependency graph is determining what is shown.  This was not readily obvious.  I ended up using the navigation buttons to get an acceptable view.  I would have liked to choose what I see. Once you see the types you want you can get a decent idea of coupling strength based on the width of the dependency lines.  Double-arrowed lines are problematic and are shown in red.  The size of the boxes will be related to the metric being displayed.  This is controlled using the Box Size drop-down in the toolbar.  Personally, I don’t find the size of the box to be helpful, so I change it to Constant Font. One nice thing about the display is that you can see the entire path of dependencies when you hover over a type.  This is done by color-coding the dependencies and dependants.  It would be nice if selecting the box for the type would lock the highlighting in place. I did find a perhaps unintended work-around to the color-coding.  You can lock the color-coding in by hovering over the type, right-clicking, and then clicking on the canvas area to clear the pop-up menu.  You can then do whatever with it including saving it to an image file with the color-coding. CQL NDepend uses a code query language (CQL) to work with your code just like it was a database.  CQL cannot be confused with the robustness of T-SQL or even LINQ, but it represents an impressive attempt at providing an expressive way to enumerate and interrogate your code. There are two main windows you’ll use when working with CQL.  The CQL Query Explorer allows you to define what queries (rules) are run as part of a report – I immediately unselected rules that I don’t want in my results.  The CQL Query Edit window is where you can view or author your own rules.  The explorer window is pretty self-explanatory, so I won’t mention it further other than to say that any queries you author will appear in the custom group. Authoring your own queries is really hard to screw-up.  The Intellisense-like pop-ups tell you what you can do while making composition easy.  I was able to create a query within two minutes of playing with the editor.  My query warns if any types that are interfaces don’t start with an “I”. WARN IF Count > 0 IN SELECT TYPES WHERE IsInterface AND !NameLike “I” The results from the CQL Query Edit window are immediate. That fact makes it useful for ad hoc querying.  It’s worth mentioning two things that could make the experience smoother.  First, out of habit from using Visual Studio I expect to be able to scroll and press Tab to select an item in the list (like Intellisense).  You have to press Enter when you scroll to the item you want.  Second, the commands are case-sensitive.  I don’t see a really good reason to enforce that. CQL has a lot of potential not just in enforcing code quality, but also enforcing architectural constraints that your enterprise has defined. Up Next My next update will be the final part of the evaluation.  I will summarize my experience and provide my conclusions on the NDepend add-in. ** View Part 1 of the Evaluation ** ** View Part 2 of the Evaluation ** Disclaimer: Patrick Smacchia contacted me about reviewing NDepend. I received a free license in return for sharing my experiences and talking about the capabilities of the add-in on this site. There is no expectation of a positive review elicited from the author of NDepend.

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  • Getting Started with jqChart for ASP.NET Web Forms

    - by jqChart
    Official Site | Samples | Download | Documentation | Forum | Twitter Introduction jqChart takes advantages of HTML5 Canvas to deliver high performance client-side charts and graphs across browsers (IE 6+, Firefox, Chrome, Opera, Safari) and devices, including iOS and Android mobile devices. Some of the key features are: High performance rendering. Animaitons. Scrolling/Zoooming. Support for unlimited number of data series and data points. Support for unlimited number of chart axes. True DateTime Axis. Logarithmic and Reversed axis scale. Large set of chart types - Bar, Column, Pie, Line, Spline, Area, Scatter, Bubble, Radar, Polar. Financial Charts - Stock Chart and Candlestick Chart. The different chart types can be easily combined.  System Requirements Browser Support jqChart supports all major browsers: Internet Explorer - 6+ Firefox Google Chrome Opera Safari jQuery version support jQuery JavaScript framework is required. We recommend using the latest official stable version of the jQuery library. Visual Studio Support jqChart for ASP.NET does not require using Visual Studio. You can use your favourite code editor. Still, the product has been tested with several versions of Visual Studio .NET and you can find the list of supported versions below: Visual Studio 2008 Visual Studio 2010 Visual Studio 2012 ASP.NET Web Forms support Supported version - ASP.NET Web Forms 3.5, 4.0 and 4.5 Installation Download and unzip the contents of the archive to any convenient location. The package contains the following folders: [bin] - Contains the assembly DLLs of the product (JQChart.Web.dll) for WebForms 3.5, 4.0 and 4.5. This is the assembly that you can reference directly in your web project (or better yet, add it to your ToolBox and then drag & drop it from there). [js] - The javascript files of jqChart and jqRangeSlider (and the needed libraries). You need to include them in your ASPX page, in order to gain the client side functionality of the chart. The first file is "jquery-1.5.1.min.js" - this is the official jQuery library. jqChart is built upon jQuery library version 1.4.3. The second file you need is the "excanvas.js" javascript file. It is used from the versions of IE, which dosn't support canvas graphics. The third is the jqChart javascript code itself, located in "jquery.jqChart.min.js". The last one is the jqRangeSlider javascript, located in "jquery.jqRangeSlider.min.js". It is used when the chart zooming is enabled. [css] - Contains the Css files that the jqChart and the jqRangeSlider need. [samples] - Contains some examples that use the jqChart. For full list of samples plese visit - jqChart for ASP.NET Samples. [themes] - Contains the themes shipped with the products. It is used from the jqRangeSlider. Since jqRangeSlider supports jQuery UI Themeroller, any theme compatible with jQuery UI ThemeRoller will work for jqRangeSlider as well. You can download any additional themes directly from jQuery UI's ThemeRoller site available here: http://jqueryui.com/themeroller/ or reference them from Microsoft's / Google's CDN. <link rel="stylesheet" type="text/css" media="screen" href="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.21/themes/smoothness/jquery-ui.css" /> The final result you will have in an ASPX page containing jqChart would be something similar to that (assuming you have copied the [js] to the Script folder and [css] to Content folder of your ASP.NET site respectively). <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="samples_cs.Default" %> <%@ Register Assembly="JQChart.Web" Namespace="JQChart.Web.UI.WebControls" TagPrefix="jqChart" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html > <head runat="server"> <title>jqChart ASP.NET Sample</title> <link rel="stylesheet" type="text/css" href="~/Content/jquery.jqChart.css" /> <link rel="stylesheet" type="text/css" href="~/Content/jquery.jqRangeSlider.css" /> <link rel="stylesheet" type="text/css" href="~/Content/themes/smoothness/jquery-ui-1.8.21.css" /> <script src="<% = ResolveUrl("~/Scripts/jquery-1.5.1.min.js") %>" type="text/javascript"></script> <script src="<% = ResolveUrl("~/Scripts/jquery.jqRangeSlider.min.js") %>" type="text/javascript"></script> <script src="<% = ResolveUrl("~/Scripts/jquery.jqChart.min.js") %>" type="text/javascript"></script> <!--[if IE]><script lang="javascript" type="text/javascript" src="<% = ResolveUrl("~/Scripts/excanvas.js") %>"></script><![endif]--> </head> <body> <form id="form1" runat="server"> <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" SelectMethod="GetData" TypeName="SamplesBrowser.Models.ChartData"></asp:ObjectDataSource> <jqChart:Chart ID="Chart1" Width="500px" Height="300px" runat="server" DataSourceID="ObjectDataSource1"> <Title Text="Chart Title"></Title> <Animation Enabled="True" Duration="00:00:01" /> <Axes> <jqChart:CategoryAxis Location="Bottom" ZoomEnabled="true"> </jqChart:CategoryAxis> </Axes> <Series> <jqChart:ColumnSeries XValuesField="Label" YValuesField="Value1" Title="Column"> </jqChart:ColumnSeries> <jqChart:LineSeries XValuesField="Label" YValuesField="Value2" Title="Line"> </jqChart:LineSeries> </Series> </jqChart:Chart> </form> </body> </html>   Official Site | Samples | Download | Documentation | Forum | Twitter

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  • difference between AJAX POST and GET

    - by Mohit Kumar
    $.ajax({ type: 'POST', url: path, data: '{AreaID: ' + parentDropdownList.val() + '}', contentType: 'application/json; charset=utf-8', dataType: 'json', success: function(response) { } }); In above code I am using type: 'POST'. My senior told me that I also can use 'GET' in type. But dint find the difference between 'POST' and 'GET' and I also want to know what is the use of type, contentType, and dataType. Could anyone one explain me why we use these type, contentType and dataType. Thanks in advance.

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  • DataTable Delete Row and AcceptChanges

    - by Pang
    DataTable DT num type name =================================== 001 A Peter 002 A Sam 003 B John public static void fun1(ref DataTable DT, String TargetType) { for (int i = 0; i < DT.Rows.Count; i++) { string type = DT.Rows[i]["type"]; if (type == TargetType) { /**Do Something**/ DT.Rows[i].Delete(); } } DT.AcceptChanges(); } My function get specific data rows in datatable according to the TargetType and use their info to do something. After the datarow is read (match the target type), it will be deleted. However, the row is deleted immediately after .Delete() execute, so the location of the next row (by i) is incorrect. For example, if TargetType is A. When i=0, the "Peter" row is deleted after .Delete executed. Then when i=1, I suppose it will locate the "Sam" row but it actually located "John" row because "Peter" row is deleted. Is there any problem in my codes?

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  • One to two relationship in Doctrine with YAML

    - by Jeremy DeGroot
    I'm working on my first Symfony project with Doctrine, and I've run into a hitch. I'm trying to express a game with two players. The relationship I want to have is PlayerOne and PlayerTwo each being keyed to an ID in the Users table. This is part of what I've got so far: Game: actAs: { Timestampable:- } columns: id: { type: integer, notnull: true, unique: true } startDate: { type: timestamp, notnull: true } playerOne: { type: integer, notnull: true } playerTwo: { type: integer, notnull: true } winner: { type: integer, notnull:true, default:0 } relations: User: { onUpdate: cascade, local: playerOne, foreign: id} User: { onUpdate: cascade, local: playerTwo, foreign: id} That doesn't work. It builds fine, but the SQL it generates only includes a constraint for playerTwo. I've tried a few other things: User: { onUpdate: cascade, local: [playerOne, playerTwo], foreign: id} Also: User: [{ onUpdate: cascade, local: playerOne, foreign: id}, { onUpdate: cascade, local: playerTwo, foreign: id}] Those last two throw errors when I try to build. Is there anyone out there who understands what I'm trying to do and can help me achieve it?

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  • How can you tell the source of the data when using the Stream.BeginRead Method?

    - by xarzu
    When using the Stream.BeginRead Method, and you are reading from a stream into a memory, how is it determined where you are reading the data from? See: http://msdn.microsoft.com/en-us/library/system.io.stream.beginread.aspx In the list of parameters, I do not see one that tells where the data is being read from: Parameters buffer Type: System.Byte[] The buffer to read the data into. offset Type: System.Int32 The byte offset in buffer at which to begin writing data read from the stream. count Type: System.Int32 The maximum number of bytes to read. callback Type: System.AsyncCallback An optional asynchronous callback, to be called when the read is complete. state Type: System.Object A user-provided object that distinguishes this particular asynchronous read request from other requests.

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  • Place an object on top of stack in ILGenerator

    - by KiNGPiN
    I have to pass a function an instance of an object, so obviously all the information to be taken as argument is to be loaded onto the evaluation stack Here is the code that i am looking for someClass SomeObject = new someClass(); il.Emit(OpCodes.LoadObject, SomeObject); il.Emit(OpCodes.CallVirt, MethodInfo Function); public void Function(Object obj) { Type type = typeof(obj); //do something w.r.t to the type } I dont require any information stored in the class just the type and i cannot use any of the primitive types to take my decision on Last i read that i can use a pointer to load the type using some opcodes ... but i am completely lost here, any help or pointers to the right direction would be great :)

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  • StreamInsight 2.1, meet LINQ

    - by Roman Schindlauer
    Someone recently called LINQ “magic” in my hearing. I leapt to LINQ’s defense immediately. Turns out some people don’t realize “magic” is can be a pejorative term. I thought LINQ needed demystification. Here’s your best demystification resource: http://blogs.msdn.com/b/mattwar/archive/2008/11/18/linq-links.aspx. I won’t repeat much of what Matt Warren says in his excellent series, but will talk about some core ideas and how they affect the 2.1 release of StreamInsight. Let’s tell the story of a LINQ query. Compile time It begins with some code: IQueryable<Product> products = ...; var query = from p in products             where p.Name == "Widget"             select p.ProductID; foreach (int id in query) {     ... When the code is compiled, the C# compiler (among other things) de-sugars the query expression (see C# spec section 7.16): ... var query = products.Where(p => p.Name == "Widget").Select(p => p.ProductID); ... Overload resolution subsequently binds the Queryable.Where<Product> and Queryable.Select<Product, int> extension methods (see C# spec sections 7.5 and 7.6.5). After overload resolution, the compiler knows something interesting about the anonymous functions (lambda syntax) in the de-sugared code: they must be converted to expression trees, i.e.,“an object structure that represents the structure of the anonymous function itself” (see C# spec section 6.5). The conversion is equivalent to the following rewrite: ... var prm1 = Expression.Parameter(typeof(Product), "p"); var prm2 = Expression.Parameter(typeof(Product), "p"); var query = Queryable.Select<Product, int>(     Queryable.Where<Product>(         products,         Expression.Lambda<Func<Product, bool>>(Expression.Property(prm1, "Name"), prm1)),         Expression.Lambda<Func<Product, int>>(Expression.Property(prm2, "ProductID"), prm2)); ... If the “products” expression had type IEnumerable<Product>, the compiler would have chosen the Enumerable.Where and Enumerable.Select extension methods instead, in which case the anonymous functions would have been converted to delegates. At this point, we’ve reduced the LINQ query to familiar code that will compile in C# 2.0. (Note that I’m using C# snippets to illustrate transformations that occur in the compiler, not to suggest a viable compiler design!) Runtime When the above program is executed, the Queryable.Where method is invoked. It takes two arguments. The first is an IQueryable<> instance that exposes an Expression property and a Provider property. The second is an expression tree. The Queryable.Where method implementation looks something like this: public static IQueryable<T> Where<T>(this IQueryable<T> source, Expression<Func<T, bool>> predicate) {     return source.Provider.CreateQuery<T>(     Expression.Call(this method, source.Expression, Expression.Quote(predicate))); } Notice that the method is really just composing a new expression tree that calls itself with arguments derived from the source and predicate arguments. Also notice that the query object returned from the method is associated with the same provider as the source query. By invoking operator methods, we’re constructing an expression tree that describes a query. Interestingly, the compiler and operator methods are colluding to construct a query expression tree. The important takeaway is that expression trees are built in one of two ways: (1) by the compiler when it sees an anonymous function that needs to be converted to an expression tree, and; (2) by a query operator method that constructs a new queryable object with an expression tree rooted in a call to the operator method (self-referential). Next we hit the foreach block. At this point, the power of LINQ queries becomes apparent. The provider is able to determine how the query expression tree is evaluated! The code that began our story was intentionally vague about the definition of the “products” collection. Maybe it is a queryable in-memory collection of products: var products = new[]     { new Product { Name = "Widget", ProductID = 1 } }.AsQueryable(); The in-memory LINQ provider works by rewriting Queryable method calls to Enumerable method calls in the query expression tree. It then compiles the expression tree and evaluates it. It should be mentioned that the provider does not blindly rewrite all Queryable calls. It only rewrites a call when its arguments have been rewritten in a way that introduces a type mismatch, e.g. the first argument to Queryable.Where<Product> being rewritten as an expression of type IEnumerable<Product> from IQueryable<Product>. The type mismatch is triggered initially by a “leaf” expression like the one associated with the AsQueryable query: when the provider recognizes one of its own leaf expressions, it replaces the expression with the original IEnumerable<> constant expression. I like to think of this rewrite process as “type irritation” because the rewritten leaf expression is like a foreign body that triggers an immune response (further rewrites) in the tree. The technique ensures that only those portions of the expression tree constructed by a particular provider are rewritten by that provider: no type irritation, no rewrite. Let’s consider the behavior of an alternative LINQ provider. If “products” is a collection created by a LINQ to SQL provider: var products = new NorthwindDataContext().Products; the provider rewrites the expression tree as a SQL query that is then evaluated by your favorite RDBMS. The predicate may ultimately be evaluated using an index! In this example, the expression associated with the Products property is the “leaf” expression. StreamInsight 2.1 For the in-memory LINQ to Objects provider, a leaf is an in-memory collection. For LINQ to SQL, a leaf is a table or view. When defining a “process” in StreamInsight 2.1, what is a leaf? To StreamInsight a leaf is logic: an adapter, a sequence, or even a query targeting an entirely different LINQ provider! How do we represent the logic? Remember that a standing query may outlive the client that provisioned it. A reference to a sequence object in the client application is therefore not terribly useful. But if we instead represent the code constructing the sequence as an expression, we can host the sequence in the server: using (var server = Server.Connect(...)) {     var app = server.Applications["my application"];     var source = app.DefineObservable(() => Observable.Range(0, 10, Scheduler.NewThread));     var query = from i in source where i % 2 == 0 select i; } Example 1: defining a source and composing a query Let’s look in more detail at what’s happening in example 1. We first connect to the remote server and retrieve an existing app. Next, we define a simple Reactive sequence using the Observable.Range method. Notice that the call to the Range method is in the body of an anonymous function. This is important because it means the source sequence definition is in the form of an expression, rather than simply an opaque reference to an IObservable<int> object. The variation in Example 2 fails. Although it looks similar, the sequence is now a reference to an in-memory observable collection: var local = Observable.Range(0, 10, Scheduler.NewThread); var source = app.DefineObservable(() => local); // can’t serialize ‘local’! Example 2: error referencing unserializable local object The Define* methods support definitions of operator tree leaves that target the StreamInsight server. These methods all have the same basic structure. The definition argument is a lambda expression taking between 0 and 16 arguments and returning a source or sink. The method returns a proxy for the source or sink that can then be used for the usual style of LINQ query composition. The “define” methods exploit the compile-time C# feature that converts anonymous functions into translatable expression trees! Query composition exploits the runtime pattern that allows expression trees to be constructed by operators taking queryable and expression (Expression<>) arguments. The practical upshot: once you’ve Defined a source, you can compose LINQ queries in the familiar way using query expressions and operator combinators. Notably, queries can be composed using pull-sequences (LINQ to Objects IQueryable<> inputs), push sequences (Reactive IQbservable<> inputs), and temporal sequences (StreamInsight IQStreamable<> inputs). You can even construct processes that span these three domains using “bridge” method overloads (ToEnumerable, ToObservable and To*Streamable). Finally, the targeted rewrite via type irritation pattern is used to ensure that StreamInsight computations can leverage other LINQ providers as well. Consider the following example (this example depends on Interactive Extensions): var source = app.DefineEnumerable((int id) =>     EnumerableEx.Using(() =>         new NorthwindDataContext(), context =>             from p in context.Products             where p.ProductID == id             select p.ProductName)); Within the definition, StreamInsight has no reason to suspect that it ‘owns’ the Queryable.Where and Queryable.Select calls, and it can therefore defer to LINQ to SQL! Let’s use this source in the context of a StreamInsight process: var sink = app.DefineObserver(() => Observer.Create<string>(Console.WriteLine)); var query = from name in source(1).ToObservable()             where name == "Widget"             select name; using (query.Bind(sink).Run("process")) {     ... } When we run the binding, the source portion which filters on product ID and projects the product name is evaluated by SQL Server. Outside of the definition, responsibility for evaluation shifts to the StreamInsight server where we create a bridge to the Reactive Framework (using ToObservable) and evaluate an additional predicate. It’s incredibly easy to define computations that span multiple domains using these new features in StreamInsight 2.1! Regards, The StreamInsight Team

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