static constructor - Page 196

Java: over-typed structures? To have many types in Object[]?

- by HH

Term over-type structure = a data structure that accepts different types, can be primitive or user-defined. I think ruby supports many types in structures such as tables. I tried a table with types 'String', 'char' and 'File' in Java but errs. How can I have over-typed structure in Java? How to show types in declaration? What about in initilization? Suppose a structure: INDEX VAR FILETYPE //0 -> file FILE //1 -> lineMap SizeSequence //2 -> type char //3 -> binary boolean //4 -> name String //5 -> path String Code import java.io.*; import java.util.*; public class Object { public static void print(char a) { System.out.println(a); } public static void print(String s) { System.out.println(s); } public static void main(String[] args) { Object[] d = new Object[6]; d[0] = new File("."); d[2] = 'T'; d[4] = "."; print(d[2]); print(d[4]); } } Errors Object.java:18: incompatible types found : java.io.File required: Object d[0] = new File("."); ^ Object.java:19: incompatible types found : char required: Object d[2] = 'T'; ^

Read the article

Silverstripe: outputting DataObjectManager in template include

- by Fraser

I have followed the tutorial here http://doc.silverstripe.org/old/modules:dataobjectmanager to create a dataobjectmanager in my CMS. It's all working perfectly there however I am having an issue getting it to output in the template. My code is as follows <?php class InfoArea extends DataObject{ static $db = array( 'Title' => 'Varchar(255)', 'Content' => 'HTMLText' ); static $has_one = array( 'ResortPage' => 'ResortPage' ); public function getCMSFields_forPopup(){ return new FieldSet( new TextField('Title'), new SimpleTinyMCEField('Content') ); } } ResortPage.php ....... static $has_many = array ( "InfoAreas" => "InfoArea" ); ....... $fields->addFieldToTab("Root.Content.AdditionalInformation", new DataObjectManager( $this, 'InfoAreas', 'InfoArea', array('Title' => 'Title','Content'=>'Content'), 'getCMSFields_forPopup' )); ........ I have a template "ResortPage.ss" which has an include "ResortInfo.ss". It is from within this include file that I need to output the DataObject. I have tried the below but it doesn't output anything <% control InfoArea %> $Title $Content <% end_control %> What am I doing wrong here? Thanks

Read the article

Arduino: Putting servos in my class causes them to rotate all the way to one side

- by user2526712

I am trying to create a new class that controls two servos. My code compiles just fine. However, when I run it, the servos just turn all the way to one direction. This seems to happen when I try instantiating the class (when in the constructor, I attach the servos in the class to pins). In My class's header file, I have [UPDATED] #ifndef ServoController_h #define ServoController_h #include "Arduino.h" #include <Servo.h> class ServoController { public: ServoController(int rotateServoPin, int elevateServoPin); void rotate(int degrees); void elevate(int degrees); private: Servo rotateServo; Servo elevateServo; int elevationAngle; int azimuthAngle; }; #endif Code so far for my Class: #include "Arduino.h" #include "ServoController.h" ServoController::ServoController(int rotateServoPin, int elevateServoPin) { azimuthAngle = 0; elevationAngle = 0; elevateServo.attach(elevateServoPin); rotateServo.attach(rotateServoPin); } void ServoController::rotate(int degrees) { //TO DO rotateServo.write(degrees); } void ServoController::elevate(int degrees) { //TO DO elevateServo.write(degrees); } And finally my arduino sketch so far is just: #include <ServoController.h> #include <Servo.h> ServoController sc(2 , 3); void setup() { } void loop() { } I'm pretty sure the circuit I am using is fine, since if I do not use my class, and just use the servo library directly in my arduino file, the servos move correctly. any ideas why this might happen? [UPDATE] I actually got this working. In my constructor, I have removed the lines to attach the servos to pins. Instead, I have added another method to my class which does the attachment. ServoController::ServoController(int rotateServoPin, int elevateServoPin) { azimuthAngle = 0; elevationAngle = 0; // elevateServo.attach(elevateServoPin); // rotateServo.attach(rotateServoPin); } void ServoController::attachPins(int rotateServoPin, int elevateServoPin) { azimuthAngle = 0; elevationAngle = 0; elevateServo.attach(elevateServoPin); rotateServo.attach(rotateServoPin); } I then call this in my sketch's setup() function: void setup() { sc.attachPins(2,3); } It seems like if I attach my servos outside of the setup() function, my problem occurs. [UPDATE July 27 9:13PM] Verified something with another test: I created a new sketch where I attached a servo before setup(): #include <Servo.h> Servo servo0; servo0.attach(2); void setup() { } void loop() // this function runs repeatedly after setup() finishes { servo0.write(90); delay(2000); servo0.write(135); delay(2000); servo0.write(45); delay(2000); } When I try to compile, Arduino throws an error: "testservotest:4: error: expected constructor, destructor, or type conversion before '.' token" So there was an error, but it was not thrown when the attach method was called from a class Thanks very much

Read the article

question about quicksort 3 way partition

- by davit-datuashvili

i want implement quicksort 3 way partition here is code public class quick3{ public static void quicksort3(int a[],int l,int r){ int k; int v=a[r]; if (r<=l) return; int i=l; int j=r; int p=l-1; int q=r; for (;;) { while (a[++i]<v); while (v<a[--j]) if (j==i) break; if (i>=j) break; swap( a,i, j); if (a[i]==v){ p++; swap(a,p,i);} if (v==a[j]){ q--; swap( a,q,j); } } swap(a,i,r); j=i-1; i=i+1; for (k=1;k<=p;k++,j--) swap(a,k,j); for (k=r-1;k>=q;k--,i++) swap(a,k,i); quicksort3(a,l,j); quicksort3(a,i,r); } public static void main(String[]args){ int a[]=new int[]{4,6,5,9,7,8,3}; quicksort3(a,0,a.length-1); for (int i=0;i<a.length;i++){ System.out.println(a[i]); } } public static void swap(int a[],int i,int j){ int t=a[i]; a[i]=a[j]; a[j]=t; } } after change result is 4 8 7 6 3 5 9 any suggestion?please help

Read the article

C# Possible to have a generic return type?

- by JL

Here is a typical function that returns either true/false; private static bool hasValue() { return true; } Now on an error, I would like to return my own custom error object with definition: public class Failure { public string failureDateTime { get; set; } public string failureReason { get; set; } } I would have expected to be able to throw this custom object for example... private static bool hasValue() { throw new Failure(); } This is not possible, and I don't want to derive Failure from System.IO.Exception because of the inability to serialize an exception in C#. What is the best practice / or ideal solution to this problem. Should I just work with private static object? Or is there a cleaner way to return a custom object or bypass the typical return type on an error (not using System.IO.Exception)? Not entirely wild about object either, because then I need to cast the result and validate it by more boolean logic.

Read the article

Type contraint problem of C#

- by user351565

I meet a problem about type contraint of c# now. I wrote a pair of methods that can convert object to string and convert string to object. ex. static string ConvertToString(Type type, object val) { if (type == typeof(string)) return (string)val; if (type == typeof(int)) return val.ToString(); if (type.InSubclassOf(typeof(CodeObject))) return ((CodeObject)val).Code; } static T ConvertToObject<T>(string str) { Type type = typeof(T); if (type == typeof(string)) return (T)(object)val; if (type == typeof(int)) return (T)(object)int.Parse(val); if (type.InSubclassOf(typeof(CodeObject))) return Codes.Get<T>(val); } where CodeObject is a base class of Employees, Offices ..., which can fetch by static method Godes.Get where T: CodeObject but the code above cannot be compiled because error #CS0314 the generic type T of method ConvertToObject have no any constraint but Codes.Get request T must be subclass of CodeObject i tried use overloading to solve the problem but not ok. is there any way to clear up the problem? like reflection?

Read the article

What is a good java data structure for storing nested items (like cities in states)?

- by anotherAlan

I'm just getting started in Java and am looking for advice on a good way to store nested sets of data. For example, I'm interested in storing city population data that can be accessed by looking up the city in a given state. (Note: eventually, other data will be stored with each city as well, this is just the first attempt at getting started.) The current approach I'm using is to have a StateList Object which contains a HashMap that stores State Objects via a string key (i.e. HashMap<String, State>). Each State Object contains its own HashMap of City Objects keyed off the city name (i.e. HashMap<String, City>). A cut down version of what I've come up with looks like this: // TestPopulation.java public class TestPopulation { public static void main(String [] args) { // build the stateList Object StateList sl = new StateList(); // get a test state State stateAl = sl.getState("AL"); // make sure it's there. if(stateAl != null) { // add a city stateAl.addCity("Abbeville"); // now grab the city City cityAbbevilleAl = stateAl.getCity("Abbeville"); cityAbbevilleAl.setPopulation(2987); System.out.print("The city has a pop of: "); System.out.println(Integer.toString(cityAbbevilleAl.getPopulation())); } // otherwise, print an error else { System.out.println("That was an invalid state"); } } } // StateList.java import java.util.*; public class StateList { // define hash map to hold the states private HashMap<String, State> theStates = new HashMap<String, State>(); // setup constructor that loads the states public StateList() { String[] stateCodes = {"AL","AK","AZ","AR","CA","CO"}; // etc... for (String s : stateCodes) { State newState = new State(s); theStates.put(s, newState); } } // define method for getting a state public State getState(String stateCode) { if(theStates.containsKey(stateCode)) { return theStates.get(stateCode); } else { return null; } } } // State.java import java.util.*; public class State { // Setup the state code String stateCode; // HashMap for cities HashMap<String, City> cities = new HashMap<String, City>(); // define the constructor public State(String newStateCode) { System.out.println("Creating State: " + newStateCode); stateCode = newStateCode; } // define the method for adding a city public void addCity(String newCityName) { City newCityObj = new City(newCityName); cities.put(newCityName, newCityObj); } // define the method for getting a city public City getCity(String cityName) { if(cities.containsKey(cityName)) { return cities.get(cityName); } else { return null; } } } // City.java public class City { // Define the instance vars String cityName; int cityPop; // setup the constructor public City(String newCityName) { cityName = newCityName; System.out.println("Created City: " + newCityName); } public void setPopulation(int newPop) { cityPop = newPop; } public int getPopulation() { return cityPop; } } This is working for me, but I'm wondering if there are gotchas that I haven't run into, or if there are alternate/better ways to do the same thing. (P.S. I know that I need to add some more error checking in, but right now, I'm focused on trying to figure out a good data structure.) (NOTE: Edited to change setPop() and getPop() to setPopulation() and getPopulation() respectively to avoid confucsion)

Read the article

list all files from directories and subdirectories in Java

- by Adnan

What would be the fastest way to list the names of files from 1000+ directories and sub-directories? EDIT; The current code I use is: import java.io.File; public class DirectoryReader { static int spc_count=-1; static void Process(File aFile) { spc_count++; String spcs = ""; for (int i = 0; i < spc_count; i++) spcs += " "; if(aFile.isFile()) System.out.println(spcs + "[FILE] " + aFile.getName()); else if (aFile.isDirectory()) { System.out.println(spcs + "[DIR] " + aFile.getName()); File[] listOfFiles = aFile.listFiles(); if(listOfFiles!=null) { for (int i = 0; i < listOfFiles.length; i++) Process(listOfFiles[i]); } else { System.out.println(spcs + " [ACCESS DENIED]"); } } spc_count--; } public static void main(String[] args) { String nam = "D:/"; File aFile = new File(nam); Process(aFile); } }

Read the article

Singletons and constants

- by devoured elysium

I am making a program which makes use of a couple of constants. At first, each time I needed to use a constant, I'd define it as //C# private static readonly int MyConstant = xxx; //Java private static final int MyConstant = xxx; in the class where I'd need it. After some time, I started to realise that some constants would be needed in more than one class. At this time, I had 3 choises: To define them in the different classes that needed it. This leads to repetition. If by some reason later I need to change one of them, I'd have to check in all classes to replace them everywhere. To define a static class/singleton with all the constants as public. If I needed a constant X in ClassA, ClassB and ClassC, I could just define it in ClassA as public, and then have ClassB and ClassC refer to them. This solution doesn't seem that good to me as it introduces even more dependencies as the classes already have between them. I ended up implementing my code with the second option. Is that the best alternative? I feel I am probably missing some other better alternative. What worries me about using the singleton here is that it is nowhere clear to a user of the class that this class is using the singleton. Maybe I could create a ConstantsClass that held all the constants needed and then I'd pass it in the constructor to the classes that'd need it? Thanks

Read the article

The cross-thread usage of "HttpContext.Current" property and related things

- by smwikipedia

I read from < Essential ASP.NET with Examples in C# the following statement: Another useful property to know about is the static Current property of the HttpContext class. This property always points to the current instance of the HttpContext class for the request being serviced. This can be convenient if you are writing helper classes that will be used from pages or other pipeline classes and may need to access the context for whatever reason. By using the static Current property to retrieve the context, you can avoid passing a reference to it to helper classes. For example, the class shown in Listing 4-1 uses the Current property of the context to access the QueryString and print something to the current response buffer. Note that for this static property to be correctly initialized, the caller must be executing on the original request thread, so if you have spawned additional threads to perform work during a request, you must take care to provide access to the context class yourself. I am wondering about the root cause of the bold part, and one thing leads to another, here is my thoughts: We know that a process can have multiple threads. Each of these threads have their own stacks, respectively. These threads also have access to a shared memory area, the heap. The stack then, as I understand it, is kind of where all the context for that thread is stored. For a thread to access something in the heap it must use a pointer, and the pointer is stored on its stack. So when we make some cross-thread calls, we must make sure that all the necessary context info is passed from the caller thread's stack to the callee thread's stack. But I am not quite sure if I made any mistake. Any comments will be deeply appreciated. Thanks. ADD Here the stack is limited to user stack.

Read the article

Is there any alternative way of writing this switch statement(C#3.0)

- by Newbie

Can it be done in a better way public static EnumFactorType GetFactorEnum(string str) { Standardization e = new Standardization(); switch (str.ToLower()) { case "beta": e.FactorType = EnumFactorType.BETA; break; case "bkp": e.FactorType = EnumFactorType.BOOK_TO_PRICE; break; case "yld": e.FactorType = EnumFactorType.DIVIDEND_YIELD; break; case "growth": e.FactorType = EnumFactorType.GROWTH; break; case "mean": e.FactorType = EnumFactorType.MARKET_CAP; break; case "momentum": e.FactorType = EnumFactorType.MOMENTUM; break; case "size": e.FactorType = EnumFactorType.SIZE; break; case "stat_fact1": e.FactorType = EnumFactorType.STAT_FACT_1; break; case "stat_fact2": e.FactorType = EnumFactorType.STAT_FACT_2; break; case "value": e.FactorType = EnumFactorType.VALUE; break; } return e.FactorType; } If I create a Static class(say Constatant) and declare variable like public static string BETA= "beta"; and then if I try to put that in the Case expression like Case Constants.BETA : e.FactorType = EnumFactorType.BETA; break; then the compiler will report error.(quite expected) So is there any other way?(I canot change the switch statement) Using C#3.0 Thanks

Read the article

Java PropertyChangeListener

- by Laphroaig

Hi, i'm trying to figure out how to listen a property change on another class. this is my code: class with the property to listen: public class ClassWithProperty { private PropertyChangeSupport changes = new PropertyChangeSupport(this); private int usersOnline; public int getUsersOnline() { return usersOnline; } public ClassWithProperty() { usersOnline = 0; while (usersOnline<10) { changes.firePropertyChange("usersOnline", usersOnline, usersOnline++); } } public void addPropertyChangeListener( PropertyChangeListener l) { changes.addPropertyChangeListener(l); } public void removePropertyChangeListener( PropertyChangeListener l) { changes.removePropertyChangeListener(l); } } class where i need to know when the property change: public class Main { private static ClassWithProperty test; public static void main(String[] args) { test = new ClassWithProperty(); test.addPropertyChangeListener(listen()); } private static PropertyChangeListener listen() { System.out.println(test.getUsersOnline()); return null; } } I have the event fired only the last time (usersOnline=10). Sorry if it can be a stupid question, i'm learning now java and can't find a solution.

Read the article

Which way of declaring a variable is fastest?

- by ADB

For a variable used in a function that is called very often and for implementation in J2ME on a blackberry (if that changed something, can you explain)? class X { int i; public void someFunc(int j) { i = 0; while( i < j ){ [...] i++; } } } or class X { static int i; public void someFunc(int j) { i = 0; while( i < j ){ [...] i++; } } } or class X { public void someFunc(int j) { int i = 0; while( i < j ){ [...] i++; } } } I know there is a difference how a static versus non-static class variable is accessed, but I don't know it would affect the speed. I also remember reading somewhere that in-function variables may be accessed faster, but I don't know why and where I read that. Background on the question: some painting function in games are called excessively often and even small difference in access time can affect the overall performance when a variable is used in a largish loop.

Read the article

select k th mimimum from array a[0..n-1]

- by davit-datuashvili

i have done folloing code from progrmming pearls here is code import java.util.*; public class select { public static int select1(int x[],int l,int u,int k){ //pre l<=k<=u //post x[l..k-1]<=x[k]<=x[k+1..u] Random r=new Random(); int t=r.nextInt(u-1-l)+l; if (l>=u) return -1 ; swap(l,t); int s=x[l]; int i=l; int j=u+1; while (true){ do { i++; }while (i<=u && x[i]<t); do { j--; }while (x[j]>t); if (i>j) break; int temp=x[i]; x[i]=x[j];x[j]=t; swap(l,j); if (j<k){ return select1(x,j+1,u,k); } } return select1(x,l,j-1,k); } public static void main(String[] args) { int x[]=new int[]{4,7,9,3,2,12,13,10,20}; select1(x,0,x.length-1,5); } public static void swap(int i,int j){ int c=i; i=j; j=c; } } but here is mistake Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1 at select.select1(select.java:21) at select.main(select.java:36) Java Result: 1 please help

Read the article

Associate two sets of values

- by PJW

I have the following code - public static int GetViewLevel(string viewLevelDesc) { try { switch (viewLevelDesc) { case "All": return 0; case "Office": return 10; case "Manager": return 50; default: throw new Exception("Invalid View Level Description"); } } catch (Exception eX) { throw new Exception("Action: GetViewLevel()" + Environment.NewLine + eX.Message); } } public static string GetViewLevelDescription(int viewLevel) { try { switch (viewLevel) { case 0: return "All"; case 10: return "Office"; case 50: return "Manager"; default: throw new Exception("Invalid View Level Description"); } } catch (Exception eX) { throw new Exception("Action: GetViewLevelDescription()" + Environment.NewLine + eX.Message); } } The two static Methods enable me to either get an int ViewLevel from a string ViewLevelDesc or vice versa. I'm sure the way I have done this is far more cumbersome than it needs to be, and I'm looking for some advice how to achieve the same objective but more concisely. The list of int / string pairs will increase significantly. The ones in the above code are just the first three I intend to use.

Read the article

Is it possible to Store Enum value in String?

- by Narasimham K

Actally my java progrem like... public class Schedule{ public static enum RepeatType { DAILY, WEEKLY, MONTHLY; } public static enum WeekdayType { MONDAY(Calendar.MONDAY), TUESDAY(Calendar.TUESDAY), WEDNESDAY( Calendar.WEDNESDAY), THURSDAY(Calendar.THURSDAY), FRIDAY( Calendar.FRIDAY), SATURDAY(Calendar.SATURDAY), SUNDAY( Calendar.SUNDAY); private int day; private WeekdayType(int day) { this.day = day; } public static List<Date> generateSchedule(RepeatType repeatType,List<WeekdayType> repeatDays) { ----------------------------- ----------------------------//hear some logic i wrote }//Method } And i'm calling the method into my Business class like following... @RemotingInclude public void createEvent(TimetableVO timetableVO) { if ("repeatDays".equals(timetableVO.getSearchKey())) { List<Date> repeatDaysList=Schedule.generateSchedule(timetableVO.getRepeatType(),timetableVO.getRepeatDays()); } } And Finally TimetableVO is @Entity @Table(name="EC_TIMETABLE") public class TimetableVO extends AbstractVO{ ----- private RepeatType repeatType; private List<WeekdayType> repeatDays;//But in this case the method generateSchedule(-,-) was not calling. ----- } So my Question is Which one is Better Statement in the Following... private List<WeekdayType> repeatDays; (or) private String repeatDays;//if we give like this `How to Convert Enum type to String` because generateSchedule() method taking enum type value....

Read the article

Finding an odd perfect number

- by Coin Bird

I wrote these two methods to determine if a number is perfect. My prof wants me to combine them to find out if there is an odd perfect number. I know there isn't one(that is known), but I need to actually write the code to prove that. The issue is with my main method. I tested the two test methods. I tried debugging and it gets stuck on the number 5, though I can't figure out why. Here is my code: public class Lab6 { public static void main (String[]args) { int testNum = 3; while (testNum != sum_of_divisors(testNum) && testNum%2 != 0) testNum++; } public static int sum_of_divisors(int numDiv) { int count = 1; int totalDivisors = 0; while (count < numDiv) if (numDiv%count == 0) { totalDivisors = totalDivisors + count; count++; } else count++; return totalDivisors; } public static boolean is_perfect(int numPerfect) { int count = 1; int totalPerfect = 0; while (totalPerfect < numPerfect) { totalPerfect = totalPerfect + count; count++; } if (numPerfect == totalPerfect) return true; else return false; } }

Read the article

getting duplicate array output - java

- by dowln

Hello, Can someone could be kind and help me out here. Thanks in advance... My code below outputs the string as duplicates. I don't want to use Sets or ArrayList. I am using java.util.Random. I am trying to write a code that checks if string has already been randomly outputted and if it does, then it won't display. Where I am going wrong and how do I fix this. public class Worldcountries { private static Random nums = new Random(); private static String[] countries = { "America", "Candada", "Chile", "Argentina" }; public static int Dice() { return (generator.nums.nextInt(6) + 1); } public String randomCounties() { String aTemp = " "; int numOfTimes = Dice(); int dup = 0; for(int i=0 ; i<numOfTimes; i++) { // I think it's in the if statement where I am going wrong. if (!countries[i].equals(countries[i])) { i = i + 1; } else { dup--; } // and maybe here aTemp = aTemp + countries[nums.nextInt(countries.length)]; aTemp = aTemp + ","; } return aTemp; } } So the output I am getting (randomly) is, "America, America, Chile" when it should be "America, Chile".

Read the article

Toorcon 15 (2013)

- by danx

The Toorcon gang (senior staff): h1kari (founder), nfiltr8, and Geo Introduction to Toorcon 15 (2013) A Tale of One Software Bypass of MS Windows 8 Secure Boot Breaching SSL, One Byte at a Time Running at 99%: Surviving an Application DoS Security Response in the Age of Mass Customized Attacks x86 Rewriting: Defeating RoP and other Shinanighans Clowntown Express: interesting bugs and running a bug bounty program Active Fingerprinting of Encrypted VPNs Making Attacks Go Backwards Mask Your Checksums—The Gorry Details Adventures with weird machines thirty years after "Reflections on Trusting Trust" Introduction to Toorcon 15 (2013) Toorcon 15 is the 15th annual security conference held in San Diego. I've attended about a third of them and blogged about previous conferences I attended here starting in 2003. As always, I've only summarized the talks I attended and interested me enough to write about them. Be aware that I may have misrepresented the speaker's remarks and that they are not my remarks or opinion, or those of my employer, so don't quote me or them. Those seeking further details may contact the speakers directly or use The Google. For some talks, I have a URL for further information. A Tale of One Software Bypass of MS Windows 8 Secure Boot Andrew Furtak and Oleksandr Bazhaniuk Yuri Bulygin, Oleksandr ("Alex") Bazhaniuk, and (not present) Andrew Furtak Yuri and Alex talked about UEFI and Bootkits and bypassing MS Windows 8 Secure Boot, with vendor recommendations. They previously gave this talk at the BlackHat 2013 conference. MS Windows 8 Secure Boot Overview UEFI (Unified Extensible Firmware Interface) is interface between hardware and OS. UEFI is processor and architecture independent. Malware can replace bootloader (bootx64.efi, bootmgfw.efi). Once replaced can modify kernel. Trivial to replace bootloader. Today many legacy bootkits—UEFI replaces them most of them. MS Windows 8 Secure Boot verifies everything you load, either through signatures or hashes. UEFI firmware relies on secure update (with signed update). You would think Secure Boot would rely on ROM (such as used for phones0, but you can't do that for PCs—PCs use writable memory with signatures DXE core verifies the UEFI boat loader(s) OS Loader (winload.efi, winresume.efi) verifies the OS kernel A chain of trust is established with a root key (Platform Key, PK), which is a cert belonging to the platform vendor. Key Exchange Keys (KEKs) verify an "authorized" database (db), and "forbidden" database (dbx). X.509 certs with SHA-1/SHA-256 hashes. Keys are stored in non-volatile (NV) flash-based NVRAM. Boot Services (BS) allow adding/deleting keys (can't be accessed once OS starts—which uses Run-Time (RT)). Root cert uses RSA-2048 public keys and PKCS#7 format signatures. SecureBoot — enable disable image signature checks SetupMode — update keys, self-signed keys, and secure boot variables CustomMode — allows updating keys Secure Boot policy settings are: always execute, never execute, allow execute on security violation, defer execute on security violation, deny execute on security violation, query user on security violation Attacking MS Windows 8 Secure Boot Secure Boot does NOT protect from physical access. Can disable from console. Each BIOS vendor implements Secure Boot differently. There are several platform and BIOS vendors. It becomes a "zoo" of implementations—which can be taken advantage of. Secure Boot is secure only when all vendors implement it correctly. Allow only UEFI firmware signed updates protect UEFI firmware from direct modification in flash memory protect FW update components program SPI controller securely protect secure boot policy settings in nvram protect runtime api disable compatibility support module which allows unsigned legacy Can corrupt the Platform Key (PK) EFI root certificate variable in SPI flash. If PK is not found, FW enters setup mode wich secure boot turned off. Can also exploit TPM in a similar manner. One is not supposed to be able to directly modify the PK in SPI flash from the OS though. But they found a bug that they can exploit from User Mode (undisclosed) and demoed the exploit. It loaded and ran their own bootkit. The exploit requires a reboot. Multiple vendors are vulnerable. They will disclose this exploit to vendors in the future. Recommendations: allow only signed updates protect UEFI fw in ROM protect EFI variable store in ROM Breaching SSL, One Byte at a Time Yoel Gluck and Angelo Prado Angelo Prado and Yoel Gluck, Salesforce.com CRIME is software that performs a "compression oracle attack." This is possible because the SSL protocol doesn't hide length, and because SSL compresses the header. CRIME requests with every possible character and measures the ciphertext length. Look for the plaintext which compresses the most and looks for the cookie one byte-at-a-time. SSL Compression uses LZ77 to reduce redundancy. Huffman coding replaces common byte sequences with shorter codes. US CERT thinks the SSL compression problem is fixed, but it isn't. They convinced CERT that it wasn't fixed and they issued a CVE. BREACH, breachattrack.com BREACH exploits the SSL response body (Accept-Encoding response, Content-Encoding). It takes advantage of the fact that the response is not compressed. BREACH uses gzip and needs fairly "stable" pages that are static for ~30 seconds. It needs attacker-supplied content (say from a web form or added to a URL parameter). BREACH listens to a session's requests and responses, then inserts extra requests and responses. Eventually, BREACH guesses a session's secret key. Can use compression to guess contents one byte at-a-time. For example, "Supersecret SupersecreX" (a wrong guess) compresses 10 bytes, and "Supersecret Supersecret" (a correct guess) compresses 11 bytes, so it can find each character by guessing every character. To start the guess, BREACH needs at least three known initial characters in the response sequence. Compression length then "leaks" information. Some roadblocks include no winners (all guesses wrong) or too many winners (multiple possibilities that compress the same). The solutions include: lookahead (guess 2 or 3 characters at-a-time instead of 1 character). Expensive rollback to last known conflict check compression ratio can brute-force first 3 "bootstrap" characters, if needed (expensive) block ciphers hide exact plain text length. Solution is to align response in advance to block size Mitigations length: use variable padding secrets: dynamic CSRF tokens per request secret: change over time separate secret to input-less servlets Future work eiter understand DEFLATE/GZIP HTTPS extensions Running at 99%: Surviving an Application DoS Ryan Huber Ryan Huber, Risk I/O Ryan first discussed various ways to do a denial of service (DoS) attack against web services. One usual method is to find a slow web page and do several wgets. Or download large files. Apache is not well suited at handling a large number of connections, but one can put something in front of it Can use Apache alternatives, such as nginx How to identify malicious hosts short, sudden web requests user-agent is obvious (curl, python) same url requested repeatedly no web page referer (not normal) hidden links. hide a link and see if a bot gets it restricted access if not your geo IP (unless the website is global) missing common headers in request regular timing first seen IP at beginning of attack count requests per hosts (usually a very large number) Use of captcha can mitigate attacks, but you'll lose a lot of genuine users. Bouncer, goo.gl/c2vyEc and www.github.com/rawdigits/Bouncer Bouncer is software written by Ryan in netflow. Bouncer has a small, unobtrusive footprint and detects DoS attempts. It closes blacklisted sockets immediately (not nice about it, no proper close connection). Aggregator collects requests and controls your web proxies. Need NTP on the front end web servers for clean data for use by bouncer. Bouncer is also useful for a popularity storm ("Slashdotting") and scraper storms. Future features: gzip collection data, documentation, consumer library, multitask, logging destroyed connections. Takeaways: DoS mitigation is easier with a complete picture Bouncer designed to make it easier to detect and defend DoS—not a complete cure Security Response in the Age of Mass Customized Attacks Peleus Uhley and Karthik Raman Peleus Uhley and Karthik Raman, Adobe ASSET, blogs.adobe.com/asset/ Peleus and Karthik talked about response to mass-customized exploits. Attackers behave much like a business. "Mass customization" refers to concept discussed in the book Future Perfect by Stan Davis of Harvard Business School. Mass customization is differentiating a product for an individual customer, but at a mass production price. For example, the same individual with a debit card receives basically the same customized ATM experience around the world. Or designing your own PC from commodity parts. Exploit kits are another example of mass customization. The kits support multiple browsers and plugins, allows new modules. Exploit kits are cheap and customizable. Organized gangs use exploit kits. A group at Berkeley looked at 77,000 malicious websites (Grier et al., "Manufacturing Compromise: The Emergence of Exploit-as-a-Service", 2012). They found 10,000 distinct binaries among them, but derived from only a dozen or so exploit kits. Characteristics of Mass Malware: potent, resilient, relatively low cost Technical characteristics: multiple OS, multipe payloads, multiple scenarios, multiple languages, obfuscation Response time for 0-day exploits has gone down from ~40 days 5 years ago to about ~10 days now. So the drive with malware is towards mass customized exploits, to avoid detection There's plenty of evicence that exploit development has Project Manager bureaucracy. They infer from the malware edicts to: support all versions of reader support all versions of windows support all versions of flash support all browsers write large complex, difficult to main code (8750 lines of JavaScript for example Exploits have "loose coupling" of multipe versions of software (adobe), OS, and browser. This allows specific attacks against specific versions of multiple pieces of software. Also allows exploits of more obscure software/OS/browsers and obscure versions. Gave examples of exploits that exploited 2, 3, 6, or 14 separate bugs. However, these complete exploits are more likely to be buggy or fragile in themselves and easier to defeat. Future research includes normalizing malware and Javascript. Conclusion: The coming trend is that mass-malware with mass zero-day attacks will result in mass customization of attacks. x86 Rewriting: Defeating RoP and other Shinanighans Richard Wartell Richard Wartell The attack vector we are addressing here is: First some malware causes a buffer overflow. The malware has no program access, but input access and buffer overflow code onto stack Later the stack became non-executable. The workaround malware used was to write a bogus return address to the stack jumping to malware Later came ASLR (Address Space Layout Randomization) to randomize memory layout and make addresses non-deterministic. The workaround malware used was to jump t existing code segments in the program that can be used in bad ways "RoP" is Return-oriented Programming attacks. RoP attacks use your own code and write return address on stack to (existing) expoitable code found in program ("gadgets"). Pinkie Pie was paid $60K last year for a RoP attack. One solution is using anti-RoP compilers that compile source code with NO return instructions. ASLR does not randomize address space, just "gadgets". IPR/ILR ("Instruction Location Randomization") randomizes each instruction with a virtual machine. Richard's goal was to randomize a binary with no source code access. He created "STIR" (Self-Transofrming Instruction Relocation). STIR disassembles binary and operates on "basic blocks" of code. The STIR disassembler is conservative in what to disassemble. Each basic block is moved to a random location in memory. Next, STIR writes new code sections with copies of "basic blocks" of code in randomized locations. The old code is copied and rewritten with jumps to new code. the original code sections in the file is marked non-executible. STIR has better entropy than ASLR in location of code. Makes brute force attacks much harder. STIR runs on MS Windows (PEM) and Linux (ELF). It eliminated 99.96% or more "gadgets" (i.e., moved the address). Overhead usually 5-10% on MS Windows, about 1.5-4% on Linux (but some code actually runs faster!). The unique thing about STIR is it requires no source access and the modified binary fully works! Current work is to rewrite code to enforce security policies. For example, don't create a *.{exe,msi,bat} file. Or don't connect to the network after reading from the disk. Clowntown Express: interesting bugs and running a bug bounty program Collin Greene Collin Greene, Facebook Collin talked about Facebook's bug bounty program. Background at FB: FB has good security frameworks, such as security teams, external audits, and cc'ing on diffs. But there's lots of "deep, dark, forgotten" parts of legacy FB code. Collin gave several examples of bountied bugs. Some bounty submissions were on software purchased from a third-party (but bounty claimers don't know and don't care). We use security questions, as does everyone else, but they are basically insecure (often easily discoverable). Collin didn't expect many bugs from the bounty program, but they ended getting 20+ good bugs in first 24 hours and good submissions continue to come in. Bug bounties bring people in with different perspectives, and are paid only for success. Bug bounty is a better use of a fixed amount of time and money versus just code review or static code analysis. The Bounty program started July 2011 and paid out $1.5 million to date. 14% of the submissions have been high priority problems that needed to be fixed immediately. The best bugs come from a small % of submitters (as with everything else)—the top paid submitters are paid 6 figures a year. Spammers like to backstab competitors. The youngest sumitter was 13. Some submitters have been hired. Bug bounties also allows to see bugs that were missed by tools or reviews, allowing improvement in the process. Bug bounties might not work for traditional software companies where the product has release cycle or is not on Internet. Active Fingerprinting of Encrypted VPNs Anna Shubina Anna Shubina, Dartmouth Institute for Security, Technology, and Society (I missed the start of her talk because another track went overtime. But I have the DVD of the talk, so I'll expand later) IPsec leaves fingerprints. Using netcat, one can easily visually distinguish various crypto chaining modes just from packet timing on a chart (example, DES-CBC versus AES-CBC) One can tell a lot about VPNs just from ping roundtrips (such as what router is used) Delayed packets are not informative about a network, especially if far away from the network More needed to explore about how TCP works in real life with respect to timing Making Attacks Go Backwards Fuzzynop FuzzyNop, Mandiant This talk is not about threat attribution (finding who), product solutions, politics, or sales pitches. But who are making these malware threats? It's not a single person or group—they have diverse skill levels. There's a lot of fat-fingered fumblers out there. Always look for low-hanging fruit first: "hiding" malware in the temp, recycle, or root directories creation of unnamed scheduled tasks obvious names of files and syscalls ("ClearEventLog") uncleared event logs. Clearing event log in itself, and time of clearing, is a red flag and good first clue to look for on a suspect system Reverse engineering is hard. Disassembler use takes practice and skill. A popular tool is IDA Pro, but it takes multiple interactive iterations to get a clean disassembly. Key loggers are used a lot in targeted attacks. They are typically custom code or built in a backdoor. A big tip-off is that non-printable characters need to be printed out (such as "[Ctrl]" "[RightShift]") or time stamp printf strings. Look for these in files. Presence is not proof they are used. Absence is not proof they are not used. Java exploits. Can parse jar file with idxparser.py and decomile Java file. Java typially used to target tech companies. Backdoors are the main persistence mechanism (provided externally) for malware. Also malware typically needs command and control. Application of Artificial Intelligence in Ad-Hoc Static Code Analysis John Ashaman John Ashaman, Security Innovation Initially John tried to analyze open source files with open source static analysis tools, but these showed thousands of false positives. Also tried using grep, but tis fails to find anything even mildly complex. So next John decided to write his own tool. His approach was to first generate a call graph then analyze the graph. However, the problem is that making a call graph is really hard. For example, one problem is "evil" coding techniques, such as passing function pointer. First the tool generated an Abstract Syntax Tree (AST) with the nodes created from method declarations and edges created from method use. Then the tool generated a control flow graph with the goal to find a path through the AST (a maze) from source to sink. The algorithm is to look at adjacent nodes to see if any are "scary" (a vulnerability), using heuristics for search order. The tool, called "Scat" (Static Code Analysis Tool), currently looks for C# vulnerabilities and some simple PHP. Later, he plans to add more PHP, then JSP and Java. For more information see his posts in Security Innovation blog and NRefactory on GitHub. Mask Your Checksums—The Gorry Details Eric (XlogicX) Davisson Eric (XlogicX) Davisson Sometimes in emailing or posting TCP/IP packets to analyze problems, you may want to mask the IP address. But to do this correctly, you need to mask the checksum too, or you'll leak information about the IP. Problem reports found in stackoverflow.com, sans.org, and pastebin.org are usually not masked, but a few companies do care. If only the IP is masked, the IP may be guessed from checksum (that is, it leaks data). Other parts of packet may leak more data about the IP. TCP and IP checksums both refer to the same data, so can get more bits of information out of using both checksums than just using one checksum. Also, one can usually determine the OS from the TTL field and ports in a packet header. If we get hundreds of possible results (16x each masked nibble that is unknown), one can do other things to narrow the results, such as look at packet contents for domain or geo information. With hundreds of results, can import as CSV format into a spreadsheet. Can corelate with geo data and see where each possibility is located. Eric then demoed a real email report with a masked IP packet attached. Was able to find the exact IP address, given the geo and university of the sender. Point is if you're going to mask a packet, do it right. Eric wouldn't usually bother, but do it correctly if at all, to not create a false impression of security. Adventures with weird machines thirty years after "Reflections on Trusting Trust" Sergey Bratus Sergey Bratus, Dartmouth College (and Julian Bangert and Rebecca Shapiro, not present) "Reflections on Trusting Trust" refers to Ken Thompson's classic 1984 paper. "You can't trust code that you did not totally create yourself." There's invisible links in the chain-of-trust, such as "well-installed microcode bugs" or in the compiler, and other planted bugs. Thompson showed how a compiler can introduce and propagate bugs in unmodified source. But suppose if there's no bugs and you trust the author, can you trust the code? Hell No! There's too many factors—it's Babylonian in nature. Why not? Well, Input is not well-defined/recognized (code's assumptions about "checked" input will be violated (bug/vunerabiliy). For example, HTML is recursive, but Regex checking is not recursive. Input well-formed but so complex there's no telling what it does For example, ELF file parsing is complex and has multiple ways of parsing. Input is seen differently by different pieces of program or toolchain Any Input is a program input executes on input handlers (drives state changes & transitions) only a well-defined execution model can be trusted (regex/DFA, PDA, CFG) Input handler either is a "recognizer" for the inputs as a well-defined language (see langsec.org) or it's a "virtual machine" for inputs to drive into pwn-age ELF ABI (UNIX/Linux executible file format) case study. Problems can arise from these steps (without planting bugs): compiler linker loader ld.so/rtld relocator DWARF (debugger info) exceptions The problem is you can't really automatically analyze code (it's the "halting problem" and undecidable). Only solution is to freeze code and sign it. But you can't freeze everything! Can't freeze ASLR or loading—must have tables and metadata. Any sufficiently complex input data is the same as VM byte code Example, ELF relocation entries + dynamic symbols == a Turing Complete Machine (TM). @bxsays created a Turing machine in Linux from relocation data (not code) in an ELF file. For more information, see Rebecca "bx" Shapiro's presentation from last year's Toorcon, "Programming Weird Machines with ELF Metadata" @bxsays did same thing with Mach-O bytecode Or a DWARF exception handling data .eh_frame + glibc == Turning Machine X86 MMU (IDT, GDT, TSS): used address translation to create a Turning Machine. Page handler reads and writes (on page fault) memory. Uses a page table, which can be used as Turning Machine byte code. Example on Github using this TM that will fly a glider across the screen Next Sergey talked about "Parser Differentials". That having one input format, but two parsers, will create confusion and opportunity for exploitation. For example, CSRs are parsed during creation by cert requestor and again by another parser at the CA. Another example is ELF—several parsers in OS tool chain, which are all different. Can have two different Program Headers (PHDRs) because ld.so parses multiple PHDRs. The second PHDR can completely transform the executable. This is described in paper in the first issue of International Journal of PoC. Conclusions trusting computers not only about bugs! Bugs are part of a problem, but no by far all of it complex data formats means bugs no "chain of trust" in Babylon! (that is, with parser differentials) we need to squeeze complexity out of data until data stops being "code equivalent" Further information See and langsec.org. USENIX WOOT 2013 (Workshop on Offensive Technologies) for "weird machines" papers and videos.

Read the article

Metro: Promises

- by Stephen.Walther

The goal of this blog entry is to describe the Promise class in the WinJS library. You can use promises whenever you need to perform an asynchronous operation such as retrieving data from a remote website or a file from the file system. Promises are used extensively in the WinJS library. Asynchronous Programming Some code executes immediately, some code requires time to complete or might never complete at all. For example, retrieving the value of a local variable is an immediate operation. Retrieving data from a remote website takes longer or might not complete at all. When an operation might take a long time to complete, you should write your code so that it executes asynchronously. Instead of waiting for an operation to complete, you should start the operation and then do something else until you receive a signal that the operation is complete. An analogy. Some telephone customer service lines require you to wait on hold – listening to really bad music – until a customer service representative is available. This is synchronous programming and very wasteful of your time. Some newer customer service lines enable you to enter your telephone number so the customer service representative can call you back when a customer representative becomes available. This approach is much less wasteful of your time because you can do useful things while waiting for the callback. There are several patterns that you can use to write code which executes asynchronously. The most popular pattern in JavaScript is the callback pattern. When you call a function which might take a long time to return a result, you pass a callback function to the function. For example, the following code (which uses jQuery) includes a function named getFlickrPhotos which returns photos from the Flickr website which match a set of tags (such as “dog” and “funny”): function getFlickrPhotos(tags, callback) { $.getJSON( "http://api.flickr.com/services/feeds/photos_public.gne?jsoncallback=?", { tags: tags, tagmode: "all", format: "json" }, function (data) { if (callback) { callback(data.items); } } ); } getFlickrPhotos("funny, dogs", function(data) { $.each(data, function(index, item) { console.log(item); }); }); The getFlickr() function includes a callback parameter. When you call the getFlickr() function, you pass a function to the callback parameter which gets executed when the getFlicker() function finishes retrieving the list of photos from the Flickr web service. In the code above, the callback function simply iterates through the results and writes each result to the console. Using callbacks is a natural way to perform asynchronous programming with JavaScript. Instead of waiting for an operation to complete, sitting there and listening to really bad music, you can get a callback when the operation is complete. Using Promises The CommonJS website defines a promise like this (http://wiki.commonjs.org/wiki/Promises): “Promises provide a well-defined interface for interacting with an object that represents the result of an action that is performed asynchronously, and may or may not be finished at any given point in time. By utilizing a standard interface, different components can return promises for asynchronous actions and consumers can utilize the promises in a predictable manner.” A promise provides a standard pattern for specifying callbacks. In the WinJS library, when you create a promise, you can specify three callbacks: a complete callback, a failure callback, and a progress callback. Promises are used extensively in the WinJS library. The methods in the animation library, the control library, and the binding library all use promises. For example, the xhr() method included in the WinJS base library returns a promise. The xhr() method wraps calls to the standard XmlHttpRequest object in a promise. The following code illustrates how you can use the xhr() method to perform an Ajax request which retrieves a file named Photos.txt: var options = { url: "/data/photos.txt" }; WinJS.xhr(options).then( function (xmlHttpRequest) { console.log("success"); var data = JSON.parse(xmlHttpRequest.responseText); console.log(data); }, function(xmlHttpRequest) { console.log("fail"); }, function(xmlHttpRequest) { console.log("progress"); } ) The WinJS.xhr() method returns a promise. The Promise class includes a then() method which accepts three callback functions: a complete callback, an error callback, and a progress callback: Promise.then(completeCallback, errorCallback, progressCallback) In the code above, three anonymous functions are passed to the then() method. The three callbacks simply write a message to the JavaScript Console. The complete callback also dumps all of the data retrieved from the photos.txt file. Creating Promises You can create your own promises by creating a new instance of the Promise class. The constructor for the Promise class requires a function which accepts three parameters: a complete, error, and progress function parameter. For example, the code below illustrates how you can create a method named wait10Seconds() which returns a promise. The progress function is called every second and the complete function is not called until 10 seconds have passed: (function () { "use strict"; var app = WinJS.Application; function wait10Seconds() { return new WinJS.Promise(function (complete, error, progress) { var seconds = 0; var intervalId = window.setInterval(function () { seconds++; progress(seconds); if (seconds > 9) { window.clearInterval(intervalId); complete(); } }, 1000); }); } app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { wait10Seconds().then( function () { console.log("complete") }, function () { console.log("error") }, function (seconds) { console.log("progress:" + seconds) } ); } } app.start(); })(); All of the work happens in the constructor function for the promise. The window.setInterval() method is used to execute code every second. Every second, the progress() callback method is called. If more than 10 seconds have passed then the complete() callback method is called and the clearInterval() method is called. When you execute the code above, you can see the output in the Visual Studio JavaScript Console. Creating a Timeout Promise In the previous section, we created a custom Promise which uses the window.setInterval() method to complete the promise after 10 seconds. We really did not need to create a custom promise because the Promise class already includes a static method for returning promises which complete after a certain interval. The code below illustrates how you can use the timeout() method. The timeout() method returns a promise which completes after a certain number of milliseconds. WinJS.Promise.timeout(3000).then( function(){console.log("complete")}, function(){console.log("error")}, function(){console.log("progress")} ); In the code above, the Promise completes after 3 seconds (3000 milliseconds). The Promise returned by the timeout() method does not support progress events. Therefore, the only message written to the console is the message “complete” after 10 seconds. Canceling Promises Some promises, but not all, support cancellation. When you cancel a promise, the promise’s error callback is executed. For example, the following code uses the WinJS.xhr() method to perform an Ajax request. However, immediately after the Ajax request is made, the request is cancelled. // Specify Ajax request options var options = { url: "/data/photos.txt" }; // Make the Ajax request var request = WinJS.xhr(options).then( function (xmlHttpRequest) { console.log("success"); }, function (xmlHttpRequest) { console.log("fail"); }, function (xmlHttpRequest) { console.log("progress"); } ); // Cancel the Ajax request request.cancel(); When you run the code above, the message “fail” is written to the Visual Studio JavaScript Console. Composing Promises You can build promises out of other promises. In other words, you can compose promises. There are two static methods of the Promise class which you can use to compose promises: the join() method and the any() method. When you join promises, a promise is complete when all of the joined promises are complete. When you use the any() method, a promise is complete when any of the promises complete. The following code illustrates how to use the join() method. A new promise is created out of two timeout promises. The new promise does not complete until both of the timeout promises complete: WinJS.Promise.join([WinJS.Promise.timeout(1000), WinJS.Promise.timeout(5000)]) .then(function () { console.log("complete"); }); The message “complete” will not be written to the JavaScript Console until both promises passed to the join() method completes. The message won’t be written for 5 seconds (5,000 milliseconds). The any() method completes when any promise passed to the any() method completes: WinJS.Promise.any([WinJS.Promise.timeout(1000), WinJS.Promise.timeout(5000)]) .then(function () { console.log("complete"); }); The code above writes the message “complete” to the JavaScript Console after 1 second (1,000 milliseconds). The message is written to the JavaScript console immediately after the first promise completes and before the second promise completes. Summary The goal of this blog entry was to describe WinJS promises. First, we discussed how promises enable you to easily write code which performs asynchronous actions. You learned how to use a promise when performing an Ajax request. Next, we discussed how you can create your own promises. You learned how to create a new promise by creating a constructor function with complete, error, and progress parameters. Finally, you learned about several advanced methods of promises. You learned how to use the timeout() method to create promises which complete after an interval of time. You also learned how to cancel promises and compose promises from other promises.

Read the article

WPF Login Verification Using Active Directory

- by psheriff

Back in October of 2009 I created a WPF login screen (Figure 1) that just showed how to create the layout for a login screen. That one sample is probably the most downloaded sample we have. So in this blog post, I thought I would update that screen and also hook it up to show how to authenticate your user against Active Directory. Figure 1: Original WPF Login Screen I have updated not only the code behind for this login screen, but also the look and feel as shown in Figure 2. Figure 2: An Updated WPF Login Screen The UI To create the UI for this login screen you can refer to my October of 2009 blog post to see how to create the borderless window. You can then look at the sample code to see how I created the linear gradient brush for the background. There are just a few differences in this screen compared to the old version. First, I changed the key image and instead of using words for the Cancel and Login buttons, I used some icons. Secondly I added a text box to hold the Domain name that you wish to authenticate against. This text box is automatically filled in if you are connected to a network. In the Window_Loaded event procedure of the winLogin window you can retrieve the user’s domain name from the Environment.UserDomainName property. For example: txtDomain.Text = Environment.UserDomainName The ADHelper Class Instead of coding the call to authenticate the user directly in the login screen I created an ADHelper class. This will make it easier if you want to add additional AD calls in the future. The ADHelper class contains just one method at this time called AuthenticateUser. This method authenticates a user name and password against the specified domain. The login screen will gather the credentials from the user such as their user name and password, and also the domain name to authenticate against. To use this ADHelper class you will need to add a reference to the System.DirectoryServices.dll in .NET. The AuthenticateUser Method In order to authenticate a user against your Active Directory you will need to supply a valid LDAP path string to the constructor of the DirectoryEntry class. The LDAP path string will be in the format LDAP://DomainName. You will also pass in the user name and password to the constructor of the DirectoryEntry class as well. With a DirectoryEntry object populated with this LDAP path string, the user name and password you will now pass this object to the constructor of a DirectorySearcher object. You then perform the FindOne method on the DirectorySearcher object. If the DirectorySearcher object returns a SearchResult then the credentials supplied are valid. If the credentials are not valid on the Active Directory then an exception is thrown. C#public bool AuthenticateUser(string domainName, string userName, string password){ bool ret = false; try { DirectoryEntry de = new DirectoryEntry("LDAP://" + domainName, userName, password); DirectorySearcher dsearch = new DirectorySearcher(de); SearchResult results = null; results = dsearch.FindOne(); ret = true; } catch { ret = false; } return ret;} Visual Basic Public Function AuthenticateUser(ByVal domainName As String, _ ByVal userName As String, ByVal password As String) As Boolean Dim ret As Boolean = False Try Dim de As New DirectoryEntry("LDAP://" & domainName, _ userName, password) Dim dsearch As New DirectorySearcher(de) Dim results As SearchResult = Nothing results = dsearch.FindOne() ret = True Catch ret = False End Try Return retEnd Function In the Click event procedure under the Login button you will find the following code that will validate the credentials that the user types into the login window. C#private void btnLogin_Click(object sender, RoutedEventArgs e){ ADHelper ad = new ADHelper(); if(ad.AuthenticateUser(txtDomain.Text, txtUserName.Text, txtPassword.Password)) DialogResult = true; else MessageBox.Show("Unable to Authenticate Using the Supplied Credentials");} Visual BasicPrivate Sub btnLogin_Click(ByVal sender As Object, _ ByVal e As RoutedEventArgs) Dim ad As New ADHelper() If ad.AuthenticateUser(txtDomain.Text, txtUserName.Text, _ txtPassword.Password) Then DialogResult = True Else MessageBox.Show("Unable to Authenticate Using the Supplied Credentials") End IfEnd Sub Displaying the Login Screen At some point when your application launches, you will need to display your login screen modally. Below is the code that you would call to display the login form (named winLogin in my sample application). This code is called from the main application form, and thus the owner of the login screen is set to “this”. You then call the ShowDialog method on the login screen to have this form displayed modally. After the user clicks on one of the two buttons you need to check to see what the DialogResult property was set to. The DialogResult property is a nullable type and thus you first need to check to see if the value has been set. C# private void DisplayLoginScreen(){ winLogin win = new winLogin(); win.Owner = this; win.ShowDialog(); if (win.DialogResult.HasValue && win.DialogResult.Value) MessageBox.Show("User Logged In"); else this.Close();} Visual Basic Private Sub DisplayLoginScreen() Dim win As New winLogin() win.Owner = Me win.ShowDialog() If win.DialogResult.HasValue And win.DialogResult.Value Then MessageBox.Show("User Logged In") Else Me.Close() End IfEnd Sub Summary Creating a nice looking login screen is fairly simple to do in WPF. Using the Active Directory services from a WPF application should make your desktop programming task easier as you do not need to create your own user authentication system. I hope this article gave you some ideas on how to create a login screen in WPF. NOTE: You can download the complete sample code for this blog entry at my website: http://www.pdsa.com/downloads. Click on Tips & Tricks, then select 'WPF Login Verification Using Active Directory' from the drop down list. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **We frequently offer a FREE gift for readers of my blog. Visit http://www.pdsa.com/Event/Blog for your FREE gift!

Read the article

Windows Phone 7 : Dragging and flicking UI controls

- by TechTwaddle

Who would want to flick and drag UI controls!? There might not be many use cases but I think some concepts here are worthy of a post. So we will create a simple silverlight application for windows phone 7, containing a canvas element on which we’ll place a button control and an image and then, as the title says, drag and flick the controls. Here’s Mainpage.xaml, <Grid x:Name="LayoutRoot" Background="Transparent"> <Grid.RowDefinitions> <RowDefinition Height="Auto"/> <RowDefinition Height="*"/> </Grid.RowDefinitions>  <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28"> <TextBlock x:Name="ApplicationTitle" Text="KINETICS" Style="{StaticResource PhoneTextNormalStyle}"/> <TextBlock x:Name="PageTitle" Text="drag and flick" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/> </StackPanel>  <Grid x:Name="ContentPanel" Grid.Row="1" > <Canvas x:Name="MainCanvas" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"> <Canvas.Background> <LinearGradientBrush StartPoint="0 0" EndPoint="0 1"> <GradientStop Offset="0" Color="Black"/> <GradientStop Offset="1.5" Color="BlanchedAlmond"/> </LinearGradientBrush> </Canvas.Background> </Canvas> </Grid> </Grid> the second row in the main grid contains a canvas element, MainCanvas, with its horizontal and vertical alignment set to stretch so that it occupies the entire grid. The canvas background is a linear gradient brush starting with Black and ending with BlanchedAlmond. We’ll add the button and image control to this canvas at run time. Moving to Mainpage.xaml.cs the Mainpage class contains the following members, public partial class MainPage : PhoneApplicationPage { Button FlickButton; Image FlickImage; FrameworkElement ElemToMove = null; double ElemVelX, ElemVelY; const double SPEED_FACTOR = 60; DispatcherTimer timer; FlickButton and FlickImage are the controls that we’ll add to the canvas. ElemToMove, ElemVelX and ElemVelY will be used by the timer callback to move the ui control. SPEED_FACTOR is used to scale the velocities of ui controls. Here’s the Mainpage constructor, // Constructor public MainPage() { InitializeComponent(); AddButtonToCanvas(); AddImageToCanvas(); timer = new DispatcherTimer(); timer.Interval = TimeSpan.FromMilliseconds(35); timer.Tick += new EventHandler(OnTimerTick); } We’ll look at those AddButton and AddImage functions in a moment. The constructor initializes a timer which fires every 35 milliseconds, this timer will be started after the flick gesture completes with some inertia. Back to AddButton and AddImage functions, void AddButtonToCanvas() { LinearGradientBrush brush; GradientStop stop1, stop2; Random rand = new Random(DateTime.Now.Millisecond); FlickButton = new Button(); FlickButton.Content = ""; FlickButton.Width = 100; FlickButton.Height = 100; brush = new LinearGradientBrush(); brush.StartPoint = new Point(0, 0); brush.EndPoint = new Point(0, 1); stop1 = new GradientStop(); stop1.Offset = 0; stop1.Color = Colors.White; stop2 = new GradientStop(); stop2.Offset = 1; stop2.Color = (Application.Current.Resources["PhoneAccentBrush"] as SolidColorBrush).Color; brush.GradientStops.Add(stop1); brush.GradientStops.Add(stop2); FlickButton.Background = brush; Canvas.SetTop(FlickButton, rand.Next(0, 400)); Canvas.SetLeft(FlickButton, rand.Next(0, 200)); MainCanvas.Children.Add(FlickButton); //subscribe to events FlickButton.ManipulationDelta += new EventHandler<ManipulationDeltaEventArgs>(OnManipulationDelta); FlickButton.ManipulationCompleted += new EventHandler<ManipulationCompletedEventArgs>(OnManipulationCompleted); } this function is basically glorifying a simple task. After creating the button and setting its height and width, its background is set to a linear gradient brush. The direction of the gradient is from top towards bottom and notice that the second stop color is the PhoneAccentColor, which changes along with the theme of the device. The line, stop2.Color = (Application.Current.Resources["PhoneAccentBrush"] as SolidColorBrush).Color; does the magic of extracting the PhoneAccentBrush from application’s resources, getting its color and assigning it to the gradient stop. AddImage function is straight forward in comparison, void AddImageToCanvas() { Random rand = new Random(DateTime.Now.Millisecond); FlickImage = new Image(); FlickImage.Source = new BitmapImage(new Uri("/images/Marble.png", UriKind.Relative)); Canvas.SetTop(FlickImage, rand.Next(0, 400)); Canvas.SetLeft(FlickImage, rand.Next(0, 200)); MainCanvas.Children.Add(FlickImage); //subscribe to events FlickImage.ManipulationDelta += new EventHandler<ManipulationDeltaEventArgs>(OnManipulationDelta); FlickImage.ManipulationCompleted += new EventHandler<ManipulationCompletedEventArgs>(OnManipulationCompleted); } The ManipulationDelta and ManipulationCompleted handlers are same for both the button and the image. OnManipulationDelta() should look familiar, a similar implementation was used in the previous post, void OnManipulationDelta(object sender, ManipulationDeltaEventArgs args) { FrameworkElement Elem = sender as FrameworkElement; double Left = Canvas.GetLeft(Elem); double Top = Canvas.GetTop(Elem); Left += args.DeltaManipulation.Translation.X; Top += args.DeltaManipulation.Translation.Y; //check for bounds if (Left < 0) { Left = 0; } else if (Left > (MainCanvas.ActualWidth - Elem.ActualWidth)) { Left = MainCanvas.ActualWidth - Elem.ActualWidth; } if (Top < 0) { Top = 0; } else if (Top > (MainCanvas.ActualHeight - Elem.ActualHeight)) { Top = MainCanvas.ActualHeight - Elem.ActualHeight; } Canvas.SetLeft(Elem, Left); Canvas.SetTop(Elem, Top); } all it does is calculate the control’s position, check for bounds and then set the top and left of the control. OnManipulationCompleted() is more interesting because here we need to check if the gesture completed with any inertia and if it did, start the timer and continue to move the ui control until it comes to a halt slowly, void OnManipulationCompleted(object sender, ManipulationCompletedEventArgs args) { FrameworkElement Elem = sender as FrameworkElement; if (args.IsInertial) { ElemToMove = Elem; Debug.WriteLine("Linear VelX:{0:0.00} VelY:{1:0.00}", args.FinalVelocities.LinearVelocity.X, args.FinalVelocities.LinearVelocity.Y); ElemVelX = args.FinalVelocities.LinearVelocity.X / SPEED_FACTOR; ElemVelY = args.FinalVelocities.LinearVelocity.Y / SPEED_FACTOR; timer.Start(); } } ManipulationCompletedEventArgs contains a member, IsInertial, which is set to true if the manipulation was completed with some inertia. args.FinalVelocities.LinearVelocity.X and .Y will contain the velocities along the X and Y axis. We need to scale down these values so they can be used to increment the ui control’s position sensibly. A reference to the ui control is stored in ElemToMove and the velocities are stored as well, these will be used in the timer callback to access the ui control. And finally, we start the timer. The timer callback function is as follows, void OnTimerTick(object sender, EventArgs e) { if (null != ElemToMove) { double Left, Top; Left = Canvas.GetLeft(ElemToMove); Top = Canvas.GetTop(ElemToMove); Left += ElemVelX; Top += ElemVelY; //check for bounds if (Left < 0) { Left = 0; ElemVelX *= -1; } else if (Left > (MainCanvas.ActualWidth - ElemToMove.ActualWidth)) { Left = MainCanvas.ActualWidth - ElemToMove.ActualWidth; ElemVelX *= -1; } if (Top < 0) { Top = 0; ElemVelY *= -1; } else if (Top > (MainCanvas.ActualHeight - ElemToMove.ActualHeight)) { Top = MainCanvas.ActualHeight - ElemToMove.ActualHeight; ElemVelY *= -1; } Canvas.SetLeft(ElemToMove, Left); Canvas.SetTop(ElemToMove, Top); //reduce x,y velocities gradually ElemVelX *= 0.9; ElemVelY *= 0.9; //when velocities become too low, break if (Math.Abs(ElemVelX) < 1.0 && Math.Abs(ElemVelY) < 1.0) { timer.Stop(); ElemToMove = null; } } } if ElemToMove is not null, we get the top and left values of the control and increment the values with their X and Y velocities. Check for bounds, and if the control goes out of bounds we reverse its velocity. Towards the end, the velocities are reduced by 10% every time the timer callback is called, and if the velocities reach too low values the timer is stopped and ElemToMove is made null. Here’s a short video of the program, the video is a little dodgy because my display driver refuses to run the animations smoothly. The flicks aren’t always recognised but the program should run well on an actual device (or a pc with better configuration), You can download the source code from here: ButtonDragAndFlick.zip

Read the article

Full Screen Video Tumblr

- by Kodi Lane

I have a tumblr theme seen on http://www.kodilane.com and i am trying to make my Video Posts full screen. I have tried editing the code but i can only get the pictures to stretch. I have attached the template i have so far, if you can spot the changes that need to be done to make the video posts stretch full screen like the pictures do i would really appreciate it. Thank You - Kodi <!DOCTYPE html> <html lang="en"> <head> <title>{Title} {block:PostSummary}- {PostSummary}{/block:PostSummary}</title> <link rel="shortcut icon" href="{Favicon}"> <link rel="alternate" type="application/rss+xml" href="{RSS}"> {block:Description} <meta name="description" content="{MetaDescription}" /> {/block:Description} <meta http-equiv="content-type" content="text/html; charset=utf-8" /> {block:Posts} <meta name="if:Reverse Description" content="0"/> <meta name="if:Include Attribution" content="1"/> <meta name="image:Background" content="http://static.tumblr.com/ffvtarv/QxLlmnswt/kims4.jpeg"/> <meta name="font:Body" content="Arial, Helvetica, sans"/> <meta name="color:Body Text" content="#fff"/> <meta name="color:Link" content="#d5d5d5"/> <meta name="color:Hover" content="#fff"/> <style type="text/css"> html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video { margin: 0; padding: 0; border: 0; font-size: 100%; font: inherit; vertical-align: baseline; } /* HTML5 display-role reset for older browsers */ article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section { display: block; } body { line-height: 1; font-family: {font:Body}; } ol, ul, .bigcats li { list-style: none; } .main ol{ list-style:decimal; margin-left:25px; margin-bottom:10px; } .main ul{ list-style: disc; margin-left:25px; margin-bottom:10px; } blockquote, q { quotes: none; font-style: italic; padding:7px 7px; display:block; } ol.notes blockquote a{ line-height:22px; } blockquote:before, blockquote:after, q:before, q:after { content: ''; content: none; } table { border-collapse: collapse; border-spacing: 0; } strong{ color:#9d9d9d; font-weight: bold; } em{ font-style: italic; } {block:IfNotReverseDescription} .article{ max-width:420px; position:fixed; bottom:43px; right:0; } {/block:IfNotReverseDescription} {block:IfReverseDescription} .article{ max-width:420px; position:fixed; bottom:43px; left:0; } {/block:IfReverseDescription} h1, h2{ position:absolute; top:-9999px; left:-9999px; } .nav{ width:100%; padding: 10px 0px 10px 0px; text-align:left; z-index: 10; color:{color:Link}; margin-left:5px; } .navwrap{ background-color:#000; position:fixed; width:100%; bottom:0px; clear:both; /* Firefox 3.6+ */ background: -moz-linear-gradient(left, rgba(0, 0, 0, .5), rgba(0, 0, 0, 0.8)); /* Safari 4-5, Chrome 1-9 */ background: -webkit-gradient(linear, left top, right top, from(rgba(0, 0, 0, .5)), to(rgba(0, 0, 0, 0.8))); /* Safari 5.1+, Chrome 10+ */ background: -webkit-linear-gradient(left, rgba(0, 0, 0, .5), rgba(0, 0, 0, 0.8)); /* Opera 11.10+ */ background: -o-linear-gradient(left, rgba(0, 0, 0, .5), rgba(0, 0, 0, 0.8)); padding-bottom:2px; box-shadow:0px 0px 3px #000000; } .nav ul li{ display:inline; font-size:13px; text-transform:uppercase; color:{color:Link}; list-style:none; text-align:center; } .nav li{ list-style: none; } .nav ul li a, .nav ul li a:visited { color:{color:Link}; padding: 10px 10px 3px 10px; } .nav ul li a:hover{ color:{color:Hover}; } a{ text-decoration:none; } .main a{ border-bottom: 1px {color:Link} dotted; color: {color:Link}; padding: 0 1px; } .main a:hover, .main a:focus{ color:{color:Hover}; border-bottom: transparent 1px solid; } a:visited, .main a:visited, { color: {color:Link}; } a:active {outline: none;} ol.notes, ol.notes li{ margin-bottom:2px; line-height:16px; } .audiometa{ padding-bottom:10px; } h3.push{ margin-bottom:10px; } h3{ margin-bottom:10px; } h3 a{ margin-bottom:10px; font-size:16px; color:{color:Hover}; } .main, .tags{ color:{color:Body Text}; display:block; padding: 15px; font-size: 12px; line-height: 16px; text-align: left; /* fallback */ background-color: #000; /* Firefox 3.6+ */ background: -moz-linear-gradient(left, rgba(0, 0, 0, .8), rgba(0, 0, 0, 0.6)); /* Safari 4-5, Chrome 1-9 */ background: -webkit-gradient(linear, left top, right top, from(rgba(0, 0, 0, .8)), to(rgba(0, 0, 0, 0.6))); /* Safari 5.1+, Chrome 10+ */ background: -webkit-linear-gradient(left, rgba(0, 0, 0, .8), rgba(0, 0, 0, 0.6)); /* Opera 11.10+ */ background: -o-linear-gradient(left, rgba(0, 0, 0, .8), rgba(0, 0, 0, 0.6)); margin-top:5px; box-shadow:0px 0px 3px #000000 } .tags{ padding: 5px 15px; padding-bottom:7px; } .main iframe, .main embed{ margin-left:-5px; margin-top:-5px; } a.more-link, .tags a, .meta a{ line-height:18px; font-size:10px; border-bottom: 1px #888 dotted; color: {color:Link}; padding: 0 1px; margin: 0 2px; } p.meta{ margin-bottom:5px; } .tags a:hover, a.more-link:hover{ color:{color:Hover}; border-bottom: 1px #FFF dotted; } .pagination{ color: {color:Body Text}; padding: 10px 15px; font-size: 10px; line-height: 16px; text-align: left; /* fallback */ background-color: #000; /* Firefox 3.6+ */ background: -moz-linear-gradient(left, rgba(0, 0, 0, .8), rgba(0, 0, 0, 0.6)); /* Safari 4-5, Chrome 1-9 */ background: -webkit-gradient(linear, left top, right top, from(rgba(0, 0, 0, .8)), to(rgba(0, 0, 0, 0.6))); /* Safari 5.1+, Chrome 10+ */ background: -webkit-linear-gradient(left, rgba(0, 0, 0, .8), rgba(0, 0, 0, 0.6)); /* Opera 11.10+ */ background: -o-linear-gradient(left, rgba(0, 0, 0, .8), rgba(0, 0, 0, 0.6)); margin-top:5px; box-shadow:0px 0px 3px #000000 } .pagination:hover{ /* Firefox 3.6+ */ background: -moz-linear-gradient(left, rgba(0, 0, 0, .6), rgba(0, 0, 0, 0.8)); /* Safari 4-5, Chrome 1-9 */ background: -webkit-gradient(linear, left top, right top, from(rgba(0, 0, 0, .6)), to(rgba(0, 0, 0, 0.8))); /* Safari 5.1+, Chrome 10+ */ background: -webkit-linear-gradient(left, rgba(0, 0, 0, .6), rgba(0, 0, 0, 0.8)); /* Opera 11.10+ */ background: -o-linear-gradient(left, rgba(0, 0, 0, .6), rgba(0, 0, 0, 0.8)); } #nextslide { width:48%; height:100%; background: url(http://static.tumblr.com/szanjxb/vI6lmo15u/forward.png) no-repeat right center, url(http://static.tumblr.com/ffvtarv/gemlmnsks/next-shadow.png) repeat-y right; position:fixed; top:0; right:0; float:left; opacity:0; filter:alpha(opacity=0); -webkit-transition: opacity .5s ease-out; -moz-transition: opacity .5s ease-out; -o-transition: opacity .5s ease-out; overflow:none; } p{ margin-bottom: 10px; } p:last-child{ margin-bottom: 0px; } #prevslide{ width:48%; float:left; height:100%; background: url(http://static.tumblr.com/szanjxb/MSClmo15g/back.png) no-repeat left center, url(http://static.tumblr.com/ffvtarv/bKulmnsl6/prev-shadow.png) repeat-y left; position:fixed; top: 0; left: 0; opacity:0; filter:alpha(opacity=0); -webkit-transition: opacity .5s ease-out; -moz-transition: opacity .5s ease-out; -o-transition: opacity .5s ease-out; } #nextslide:hover, #prevslide:hover{ filter:alpha(opacity=100); opacity:1.0; -webkit-transition: opacity .2s ease-out; -moz-transition: opacity .2s ease-out; -o-transition: opacity .2s ease-out; } p.time{ padding-bottom:10px; margin-bottom:10px; text-align: right; } .left{ float:left; } .right{ float:right; } .button{ position:fixed; bottom: 9px; right: 15px; line-height:12px; font-size:13px; color:{color:Link}; cursor: pointer; float:left; padding-bottom:1px; border-bottom: 2px solid transparent; } .button:hover{ color:{color:Link}; } .notes{ line-height: 11px; } ol.notes li{ list-style: none; } .clear { clear: both; display: block; overflow: hidden; visibility: hidden; width: 0; height: 0; } .hidden{ display:none; } {block:Photo} body {background: url({PhotoURL-HighRes}) no-repeat center center fixed black; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover;} {/block:Photo} {block:Text} body {background: url({image:Background}) no-repeat center center fixed black; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover;} {/block:Text} {block:Video} body {background: url({image:Background}) no-repeat center center fixed black; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover;} {/block:Video} {block:Quote} body {background: url({image:Background}) no-repeat center center fixed black; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover;} {/block:Quote} {block:Link} body {background: url({image:Background}) no-repeat center center fixed black; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover;} {/block:Link} {block:Audio} body {background: url({image:Background}) no-repeat center center fixed black; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover;} {block:AlbumArt} body{ background: url({AlbumArtURL}) no-repeat center center fixed black; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover; } {/block:AlbumArt} {/block:Audio} {block:Answer} body {background: url({image:Background}) no-repeat center center fixed black; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover;} {/block:Answer} {block:Chat} body {background: url({image:Background}) no-repeat center center fixed black; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover;} {/block:Chat} {CustomCSS} </style> <script src="http://static.tumblr.com/ffvtarv/W6Llmnske/jquery-git.js"></script> <script src="http://static.tumblr.com/ffvtarv/QpUlmnsje/jquery.cookie.js"></script> <script> var uiStatus = $.cookie("uiStatus") $(document).ready(function(){ if(uiStatus == 'hidden') { $(".article,.navwrap").hide() }; $(".button").click(function () { $(".article,.navwrap").fadeToggle("slow", "swing"); if(uiStatus == 'hidden') { $.cookie("uiStatus", "visible"); } else { $.cookie("uiStatus", "hidden"); }; }); }); </script> </head> <h1><a href="/">{Title}</a></h1> <h2>{Description}</h2>  {block:Pagination} {block:PreviousPage} <a href="{PreviousPage}" title="Next Post"><div id="nextslide"></div></a> {/block:PreviousPage} {block:NextPage} <a href="{NextPage}" title="Previous Post"><div id="prevslide"></div></a> {/block:NextPage} {/block:Pagination} {block:PermalinkPagination} {block:PreviousPost} <a href="{PreviousPost}" title="Previous Post"><div id="prevslide"></div></a> {/block:PreviousPost} {block:NextPost} <a href="{NextPost}" title="Next Post"><div id="nextslide"></div></a> {/block:NextPost} {/block:PermalinkPagination} <div class="article"> {block:Pagination} {block:PreviousPage} <a href="{PreviousPage}" title="Newer Post"><div class="pagination">Newer Post</div></a> {/block:PreviousPage} {block:NextPage} <a href="{NextPage}" title="Older Post"><div class="pagination">Older Post</div></a> {/block:NextPage} {/block:Pagination} {block:PermalinkPagination} {block:NextPost} <a href="{NextPost}" title="Newer Post"><div class="pagination">Newer Post</div></a> {/block:NextPost} {block:PreviousPost} <a href="{PreviousPost}" title="Older Post"><div class="pagination">Older Post</div></a> {/block:PreviousPost} {/block:PermalinkPagination} {block:HasTags} <div class="tags"> {block:Tags} <a href="{TagURL}">{Tag}</a> {/block:Tags} </div> {/block:HasTags} <div class="main"> {block:Photo} {block:Caption} {Caption} {/block:Caption} {/block:Photo} {block:Video} {Video-400} {block:Caption} {Caption} {/block:Caption} {/block:Video} {block:Link} <h3><a href="{URL}" target="{Target}">{Name}</a></h3> {block:Description} {Description} {/block:Description} {/block:Link} {block:Quote} <h3>{Quote}</h3> {block:Source} <strong><p>{Source}</p></strong> {/block:Source} {/block:Quote} {block:Audio} {AudioPlayerBlack} <div class="audiometa"> {block:Artist} {Artist} {/block:Artist} {block:Album} {Album} {/block:Album} {block:TrackName} {TrackName} {/block:TrackName} </div> {block:Caption} {Caption} {/block:Caption} {/block:Audio} {block:Chat} <h3 class="push">{Title}</h3> {block:Lines} <p class="chat {Alt}"><strong>{block:Label}{Label}{/block:Label}</strong> {Line}</p> {/block:Lines} {/block:Chat} {block:Text} {Body} {block:Text} <p class="meta"> <a href="http://tmv.proto.jp/reblog.php?post_url={Permalink};" title="Reblog this" class="more-link left">Reblog</a> <span class="hidden">{block:Photo}{LinkOpenTag}Source{LinkCloseTag}{/block:Photo}</span> <a href="{Permalink}" title="Permalink{PhotoAlt}" class="more-link right notes">{NoteCountWithLabel}</a> </p> <div class="clear"></div> </div> </div> <script type="text/javascript"> document.onkeyup = KeyCheck; function KeyCheck(e) { var KeyID = (window.event) ? event.keyCode : e.keyCode; switch(KeyID) { {block:Pagination} {block:PreviousPage} case 39: window.location = "{PreviousPage}"; break; {/block:PreviousPage} {block:NextPage} case 37: window.location = "{NextPage}"; break; {/block:NextPage} {/block:Pagination} {block:PermalinkPagination} {block:PreviousPost} case 39: window.location = "{NextPost}"; break; {/block:PreviousPost} {block:NextPost} case 37: window.location = "{PreviousPost}"; break; {/block:NextPost} {/block:PermalinkPagination} } } </script> <div class="navwrap"> <div class="nav"> <ul> <li><a href="/" title="{Title}">KODI LANE</a></li> <li><a href="/archive" title="Archive of posts">Archive</a></li> {block:AskEnabled}<li><a href="/ask" title="Ask">{AskLabel}</a></li>{/block:AskEnabled} {block:SubmissionsEnabled}<li><a href="/submit" title="Submit">{SubmitLabel}</a></li>{/block:SubmissionsEnabled} {block:HasPages}{block:Pages}<li><a href="{URL}">{Label}</a></li>{/block:Pages}{/block:HasPages} {block:IfIncludeAttribution}<li><a href="http://jonathanhaggard.com/">Theme by Jon</a></li>{/block:IfIncludeAttribution} </ul> </div> </div> <div class="button">HIDE/SHOW UI</div> {/block:Posts}

Read the article

Conway's Game of Life - C++ and Qt

- by Jeff Bridge

I've done all of the layouts and have most of the code written even. But, I'm stuck in two places. 1) I'm not quite sure how to set up the timer. Am I using it correctly in the gridwindow class? And, am I used the timer functions/signals/slots correctly with the other gridwindow functions. 2) In GridWindow's timerFired() function, I'm having trouble checking/creating the vector-vectors. I wrote out in the comments in that function exactly what I am trying to do. Any help would be much appreciated. main.cpp // Main file for running the grid window application. #include <QApplication> #include "gridwindow.h" //#include "timerwindow.h" #include <stdexcept> #include <string> #include <fstream> #include <sstream> #include <iostream> void Welcome(); // Welcome Function - Prints upon running program; outputs program name, student name/id, class section. void Rules(); // Rules Function: Prints the rules for Conway's Game of Life. using namespace std; // A simple main method to create the window class and then pop it up on the screen. int main(int argc, char *argv[]) { Welcome(); // Calls Welcome function to print student/assignment info. Rules(); // Prints Conway's Game Rules. QApplication app(argc, argv); // Creates the overall windowed application. int rows = 25, cols = 35; //The number of rows & columns in the game grid. GridWindow widget(NULL,rows,cols); // Creates the actual window (for the grid). widget.show(); // Shows the window on the screen. return app.exec(); // Goes into visual loop; starts executing GUI. } // Welcome Function: Prints my name/id, my class number, the assignment, and the program name. void Welcome() { cout << endl; cout << "-------------------------------------------------------------------------------------------------" << endl; cout << "Name/ID - Gabe Audick #7681539807" << endl; cout << "Class/Assignment - CSCI-102 Disccusion 29915: Homework Assignment #4" << endl; cout << "-------------------------------------------------------------------------------------------------" << endl << endl; } // Rules Function: Prints the rules for Conway's Game of Life. void Rules() { cout << "Welcome to Conway's Game of Life." << endl; cout << "Game Rules:" << endl; cout << "\t 1) Any living cell with fewer than two living neighbours dies, as if caused by underpopulation." << endl; cout << "\t 2) Any live cell with more than three live neighbours dies, as if by overcrowding." << endl; cout << "\t 3) Any live cell with two or three live neighbours lives on to the next generation." << endl; cout << "\t 4) Any dead cell with exactly three live neighbours becomes a live cell." << endl << endl; cout << "Enjoy." << endl << endl; } gridcell.h // A header file for a class representing a single cell in a grid of cells. #ifndef GRIDCELL_H_ #define GRIDCELL_H_ #include <QPalette> #include <QColor> #include <QPushButton> #include <Qt> #include <QWidget> #include <QFrame> #include <QHBoxLayout> #include <iostream> // An enum representing the two different states a cell can have. enum CellType { DEAD, // DEAD = Dead Cell. --> Color = White. LIVE // LIVE = Living Cell. ---> Color = White. }; /* Class: GridCell. A class representing a single cell in a grid. Each cell is implemented as a QT QFrame that contains a single QPushButton. The button is sized so that it takes up the entire frame. Each cell also keeps track of what type of cell it is based on the CellType enum. */ class GridCell : public QFrame { Q_OBJECT // Macro allowing us to have signals & slots on this object. private: QPushButton* button; // The button inside the cell that gives its clickability. CellType type; // The type of cell (DEAD or LIVE.) public slots: void handleClick(); // Callback for handling a click on the current cell. void setType(CellType type); // Cell type mutator. Calls the "redrawCell" function. signals: void typeChanged(CellType type); // Signal to notify listeners when the cell type has changed. public: GridCell(QWidget *parent = NULL); // Constructor for creating a cell. Takes parent widget or default parent to NULL. virtual ~GridCell(); // Destructor. void redrawCell(); // Redraws cell: Sets new type/color. CellType getType() const; //Simple getter for the cell type. private: Qt::GlobalColor getColorForCellType(); // Helper method. Returns color that cell should be based from its value. }; #endif gridcell.cpp #include <iostream> #include "gridcell.h" #include "utility.h" using namespace std; // Constructor: Creates a grid cell. GridCell::GridCell(QWidget *parent) : QFrame(parent) { this->type = DEAD; // Default: Cell is DEAD (white). setFrameStyle(QFrame::Box); // Set the frame style. This is what gives each box its black border. this->button = new QPushButton(this); //Creates button that fills entirety of each grid cell. this->button->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding); // Expands button to fill space. this->button->setMinimumSize(19,19); //width,height // Min height and width of button. QHBoxLayout *layout = new QHBoxLayout(); //Creates a simple layout to hold our button and add the button to it. layout->addWidget(this->button); setLayout(layout); layout->setStretchFactor(this->button,1); // Lets the buttons expand all the way to the edges of the current frame with no space leftover layout->setContentsMargins(0,0,0,0); layout->setSpacing(0); connect(this->button,SIGNAL(clicked()),this,SLOT(handleClick())); // Connects clicked signal with handleClick slot. redrawCell(); // Calls function to redraw (set new type for) the cell. } // Basic destructor. GridCell::~GridCell() { delete this->button; } // Accessor for the cell type. CellType GridCell::getType() const { return(this->type); } // Mutator for the cell type. Also has the side effect of causing the cell to be redrawn on the GUI. void GridCell::setType(CellType type) { this->type = type; redrawCell(); } // Handler slot for button clicks. This method is called whenever the user clicks on this cell in the grid. void GridCell::handleClick() { // When clicked on... if(this->type == DEAD) // If type is DEAD (white), change to LIVE (black). type = LIVE; else type = DEAD; // If type is LIVE (black), change to DEAD (white). setType(type); // Sets new type (color). setType Calls redrawCell() to recolor. } // Method to check cell type and return the color of that type. Qt::GlobalColor GridCell::getColorForCellType() { switch(this->type) { default: case DEAD: return Qt::white; case LIVE: return Qt::black; } } // Helper method. Forces current cell to be redrawn on the GUI. Called whenever the setType method is invoked. void GridCell::redrawCell() { Qt::GlobalColor gc = getColorForCellType(); //Find out what color this cell should be. this->button->setPalette(QPalette(gc,gc)); //Force the button in the cell to be the proper color. this->button->setAutoFillBackground(true); this->button->setFlat(true); //Force QT to NOT draw the borders on the button } gridwindow.h // A header file for a QT window that holds a grid of cells. #ifndef GRIDWINDOW_H_ #define GRIDWINDOW_H_ #include <vector> #include <QWidget> #include <QTimer> #include <QGridLayout> #include <QLabel> #include <QApplication> #include "gridcell.h" /* class GridWindow: This is the class representing the whole window that comes up when this program runs. It contains a header section with a title, a middle section of MxN cells and a bottom section with buttons. */ class GridWindow : public QWidget { Q_OBJECT // Macro to allow this object to have signals & slots. private: std::vector<std::vector<GridCell*> > cells; // A 2D vector containing pointers to all the cells in the grid. QLabel *title; // A pointer to the Title text on the window. QTimer *timer; // Creates timer object. public slots: void handleClear(); // Handler function for clicking the Clear button. void handleStart(); // Handler function for clicking the Start button. void handlePause(); // Handler function for clicking the Pause button. void timerFired(); // Method called whenever timer fires. public: GridWindow(QWidget *parent = NULL,int rows=3,int cols=3); // Constructor. virtual ~GridWindow(); // Destructor. std::vector<std::vector<GridCell*> >& getCells(); // Accessor for the array of grid cells. private: QHBoxLayout* setupHeader(); // Helper function to construct the GUI header. QGridLayout* setupGrid(int rows,int cols); // Helper function to constructor the GUI's grid. QHBoxLayout* setupButtonRow(); // Helper function to setup the row of buttons at the bottom. }; #endif gridwindow.cpp #include <iostream> #include "gridwindow.h" using namespace std; // Constructor for window. It constructs the three portions of the GUI and lays them out vertically. GridWindow::GridWindow(QWidget *parent,int rows,int cols) : QWidget(parent) { QHBoxLayout *header = setupHeader(); // Setup the title at the top. QGridLayout *grid = setupGrid(rows,cols); // Setup the grid of colored cells in the middle. QHBoxLayout *buttonRow = setupButtonRow(); // Setup the row of buttons across the bottom. QVBoxLayout *layout = new QVBoxLayout(); // Puts everything together. layout->addLayout(header); layout->addLayout(grid); layout->addLayout(buttonRow); setLayout(layout); } // Destructor. GridWindow::~GridWindow() { delete title; } // Builds header section of the GUI. QHBoxLayout* GridWindow::setupHeader() { QHBoxLayout *header = new QHBoxLayout(); // Creates horizontal box. header->setAlignment(Qt::AlignHCenter); this->title = new QLabel("CONWAY'S GAME OF LIFE",this); // Creates big, bold, centered label (title): "Conway's Game of Life." this->title->setAlignment(Qt::AlignHCenter); this->title->setFont(QFont("Arial", 32, QFont::Bold)); header->addWidget(this->title); // Adds widget to layout. return header; // Returns header to grid window. } // Builds the grid of cells. This method populates the grid's 2D array of GridCells with MxN cells. QGridLayout* GridWindow::setupGrid(int rows,int cols) { QGridLayout *grid = new QGridLayout(); // Creates grid layout. grid->setHorizontalSpacing(0); // No empty spaces. Cells should be contiguous. grid->setVerticalSpacing(0); grid->setSpacing(0); grid->setAlignment(Qt::AlignHCenter); for(int i=0; i < rows; i++) //Each row is a vector of grid cells. { std::vector<GridCell*> row; // Creates new vector for current row. cells.push_back(row); for(int j=0; j < cols; j++) { GridCell *cell = new GridCell(); // Creates and adds new cell to row. cells.at(i).push_back(cell); grid->addWidget(cell,i,j); // Adds to cell to grid layout. Column expands vertically. grid->setColumnStretch(j,1); } grid->setRowStretch(i,1); // Sets row expansion horizontally. } return grid; // Returns grid. } // Builds footer section of the GUI. QHBoxLayout* GridWindow::setupButtonRow() { QHBoxLayout *buttonRow = new QHBoxLayout(); // Creates horizontal box for buttons. buttonRow->setAlignment(Qt::AlignHCenter); // Clear Button - Clears cell; sets them all to DEAD/white. QPushButton *clearButton = new QPushButton("CLEAR"); clearButton->setFixedSize(100,25); connect(clearButton, SIGNAL(clicked()), this, SLOT(handleClear())); buttonRow->addWidget(clearButton); // Start Button - Starts game when user clicks. Or, resumes game after being paused. QPushButton *startButton = new QPushButton("START/RESUME"); startButton->setFixedSize(100,25); connect(startButton, SIGNAL(clicked()), this, SLOT(handleStart())); buttonRow->addWidget(startButton); // Pause Button - Pauses simulation of game. QPushButton *pauseButton = new QPushButton("PAUSE"); pauseButton->setFixedSize(100,25); connect(pauseButton, SIGNAL(clicked()), this, SLOT(handlePause())); buttonRow->addWidget(pauseButton); // Quit Button - Exits program. QPushButton *quitButton = new QPushButton("EXIT"); quitButton->setFixedSize(100,25); connect(quitButton, SIGNAL(clicked()), qApp, SLOT(quit())); buttonRow->addWidget(quitButton); return buttonRow; // Returns bottom of layout. } /* SLOT method for handling clicks on the "clear" button. Receives "clicked" signals on the "Clear" button and sets all cells to DEAD. */ void GridWindow::handleClear() { for(unsigned int row=0; row < cells.size(); row++) // Loops through current rows' cells. { for(unsigned int col=0; col < cells[row].size(); col++) { GridCell *cell = cells[row][col]; // Grab the current cell & set its value to dead. cell->setType(DEAD); } } } /* SLOT method for handling clicks on the "start" button. Receives "clicked" signals on the "start" button and begins game simulation. */ void GridWindow::handleStart() { this->timer = new QTimer(this); // Creates new timer. connect(this->timer, SIGNAL(timeout()), this, SLOT(timerFired())); // Connect "timerFired" method class to the "timeout" signal fired by the timer. this->timer->start(500); // Timer to fire every 500 milliseconds. } /* SLOT method for handling clicks on the "pause" button. Receives "clicked" signals on the "pause" button and stops the game simulation. */ void GridWindow::handlePause() { this->timer->stop(); // Stops the timer. delete this->timer; // Deletes timer. } // Accessor method - Gets the 2D vector of grid cells. std::vector<std::vector<GridCell*> >& GridWindow::getCells() { return this->cells; } void GridWindow::timerFired() { // I'm not sure how to write this code. // I want to take the original vector-vector, and also make a new, empty vector-vector of the same size. // I would then go through the code below with the original vector, and apply the rules to the new vector-vector. // Finally, I would make the new vector-vecotr the original vector-vector. (That would be one step in the simulation.) cout << cells[1][2]; /* for (unsigned int m = 0; m < original.size(); m++) { for (unsigned int n = 0; n < original.at(m).size(); n++) { unsigned int neighbors = 0; //Begin counting number of neighbors. if (original[m-1][n-1].getType() == LIVE) // If a cell next to [i][j] is LIVE, add one to the neighbor count. neighbors += 1; if (original[m-1][n].getType() == LIVE) neighbors += 1; if (original[m-1][n+1].getType() == LIVE) neighbors += 1; if (original[m][n-1].getType() == LIVE) neighbors += 1; if (original[m][n+1].getType() == LIVE) neighbors += 1; if (original[m+1][n-1].getType() == LIVE) neighbors += 1; if (original[m+1][n].getType() == LIVE) neighbors += 1; if (original[m+1][n+1].getType() == LIVE) neighbors += 1; if (original[m][n].getType() == LIVE && neighbors < 2) // Apply game rules to cells: Create new, updated grid with the roundtwo vector. roundtwo[m][n].setType(LIVE); else if (original[m][n].getType() == LIVE && neighbors > 3) roundtwo[m][n].setType(DEAD); else if (original[m][n].getType() == LIVE && (neighbors == 2 || neighbors == 3)) roundtwo[m][n].setType(LIVE); else if (original[m][n].getType() == DEAD && neighbors == 3) roundtwo[m][n].setType(LIVE); } }*/ }

Read the article

Hosting the Razor Engine for Templating in Non-Web Applications

- by Rick Strahl

Microsoft’s new Razor HTML Rendering Engine that is currently shipping with ASP.NET MVC previews can be used outside of ASP.NET. Razor is an alternative view engine that can be used instead of the ASP.NET Page engine that currently works with ASP.NET WebForms and MVC. It provides a simpler and more readable markup syntax and is much more light weight in terms of functionality than the full blown WebForms Page engine, focusing only on features that are more along the lines of a pure view engine (or classic ASP!) with focus on expression and code rendering rather than a complex control/object model. Like the Page engine though, the parser understands .NET code syntax which can be embedded into templates, and behind the scenes the engine compiles markup and script code into an executing piece of .NET code in an assembly. Although it ships as part of the ASP.NET MVC and WebMatrix the Razor Engine itself is not directly dependent on ASP.NET or IIS or HTTP in any way. And although there are some markup and rendering features that are optimized for HTML based output generation, Razor is essentially a free standing template engine. And what’s really nice is that unlike the ASP.NET Runtime, Razor is fairly easy to host inside of your own non-Web applications to provide templating functionality. Templating in non-Web Applications? Yes please! So why might you host a template engine in your non-Web application? Template rendering is useful in many places and I have a number of applications that make heavy use of it. One of my applications – West Wind Html Help Builder - exclusively uses template based rendering to merge user supplied help text content into customizable and executable HTML markup templates that provide HTML output for CHM style HTML Help. This is an older product and it’s not actually using .NET at the moment – and this is one reason I’m looking at Razor for script hosting at the moment. For a few .NET applications though I’ve actually used the ASP.NET Runtime hosting to provide templating and mail merge style functionality and while that works reasonably well it’s a very heavy handed approach. It’s very resource intensive and has potential issues with versioning in various different versions of .NET. The generic implementation I created in the article above requires a lot of fix up to mimic an HTTP request in a non-HTTP environment and there are a lot of little things that have to happen to ensure that the ASP.NET runtime works properly most of it having nothing to do with the templating aspect but just satisfying ASP.NET’s requirements. The Razor Engine on the other hand is fairly light weight and completely decoupled from the ASP.NET runtime and the HTTP processing. Rather it’s a pure template engine whose sole purpose is to render text templates. Hosting this engine in your own applications can be accomplished with a reasonable amount of code (actually just a few lines with the tools I’m about to describe) and without having to fake HTTP requests. It’s also much lighter on resource usage and you can easily attach custom properties to your base template implementation to easily pass context from the parent application into templates all of which was rather complicated with ASP.NET runtime hosting. Installing the Razor Template Engine You can get Razor as part of the MVC 3 (RC and later) or Web Matrix. Both are available as downloadable components from the Web Platform Installer Version 3.0 (!important – V2 doesn’t show these components). If you already have that version of the WPI installed just fire it up. You can get the latest version of the Web Platform Installer from here: http://www.microsoft.com/web/gallery/install.aspx Once the platform Installer 3.0 is installed install either MVC 3 or ASP.NET Web Pages. Once installed you’ll find a System.Web.Razor assembly in C:\Program Files\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\Assemblies\System.Web.Razor.dll which you can add as a reference to your project. Creating a Wrapper The basic Razor Hosting API is pretty simple and you can host Razor with a (large-ish) handful of lines of code. I’ll show the basics of it later in this article. However, if you want to customize the rendering and handle assembly and namespace includes for the markup as well as deal with text and file inputs as well as forcing Razor to run in a separate AppDomain so you can unload the code-generated assemblies and deal with assembly caching for re-used templates little more work is required to create something that is more easily reusable. For this reason I created a Razor Hosting wrapper project that combines a bunch of this functionality into an easy to use hosting class, a hosting factory that can load the engine in a separate AppDomain and a couple of hosting containers that provided folder based and string based caching for templates for an easily embeddable and reusable engine with easy to use syntax. If you just want the code and play with the samples and source go grab the latest code from the Subversion Repository at: http://www.west-wind.com:8080/svn/articles/trunk/RazorHosting/ or a snapshot from: http://www.west-wind.com/files/tools/RazorHosting.zip Getting Started Before I get into how hosting with Razor works, let’s take a look at how you can get up and running quickly with the wrapper classes provided. It only takes a few lines of code. The easiest way to use these Razor Hosting Wrappers is to use one of the two HostContainers provided. One is for hosting Razor scripts in a directory and rendering them as relative paths from these script files on disk. The other HostContainer serves razor scripts from string templates… Let’s start with a very simple template that displays some simple expressions, some code blocks and demonstrates rendering some data from contextual data that you pass to the template in the form of a ‘context’. Here’s a simple Razor template: @using System.Reflection Hello @Context.FirstName! Your entry was entered on: @Context.Entered @{ // Code block: Update the host Windows Form passed in through the context Context.WinForm.Text = "Hello World from Razor at " + DateTime.Now.ToString(); } AppDomain Id: @AppDomain.CurrentDomain.FriendlyName Assembly: @Assembly.GetExecutingAssembly().FullName Code based output: @{ // Write output with Response object from code string output = string.Empty; for (int i = 0; i < 10; i++) { output += i.ToString() + " "; } Response.Write(output); } Pretty easy to see what’s going on here. The only unusual thing in this code is the Context object which is an arbitrary object I’m passing from the host to the template by way of the template base class. I’m also displaying the current AppDomain and the executing Assembly name so you can see how compiling and running a template actually loads up new assemblies. Also note that as part of my context I’m passing a reference to the current Windows Form down to the template and changing the title from within the script. It’s a silly example, but it demonstrates two-way communication between host and template and back which can be very powerful. The easiest way to quickly render this template is to use the RazorEngine<TTemplateBase> class. The generic parameter specifies a template base class type that is used by Razor internally to generate the class it generates from a template. The default implementation provided in my RazorHosting wrapper is RazorTemplateBase. Here’s a simple one that renders from a string and outputs a string: var engine = new RazorEngine<RazorTemplateBase>(); // we can pass any object as context - here create a custom context var context = new CustomContext() { WinForm = this, FirstName = "Rick", Entered = DateTime.Now.AddDays(-10) }; string output = engine.RenderTemplate(this.txtSource.Text new string[] { "System.Windows.Forms.dll" }, context); if (output == null) this.txtResult.Text = "*** ERROR:\r\n" + engine.ErrorMessage; else this.txtResult.Text = output; Simple enough. This code renders a template from a string input and returns a result back as a string. It creates a custom context and passes that to the template which can then access the Context’s properties. Note that anything passed as ‘context’ must be serializable (or MarshalByRefObject) – otherwise you get an exception when passing the reference over AppDomain boundaries (discussed later). Passing a context is optional, but is a key feature in being able to share data between the host application and the template. Note that we use the Context object to access FirstName, Entered and even the host Windows Form object which is used in the template to change the Window caption from within the script! In the code above all the work happens in the RenderTemplate method which provide a variety of overloads to read and write to and from strings, files and TextReaders/Writers. Here’s another example that renders from a file input using a TextReader: using (reader = new StreamReader("templates\\simple.csHtml", true)) { result = host.RenderTemplate(reader, new string[] { "System.Windows.Forms.dll" }, this.CustomContext); } RenderTemplate() is fairly high level and it handles loading of the runtime, compiling into an assembly and rendering of the template. If you want more control you can use the lower level methods to control each step of the way which is important for the HostContainers I’ll discuss later. Basically for those scenarios you want to separate out loading of the engine, compiling into an assembly and then rendering the template from the assembly. Why? So we can keep assemblies cached. In the code above a new assembly is created for each template rendered which is inefficient and uses up resources. Depending on the size of your templates and how often you fire them you can chew through memory very quickly. This slighter lower level approach is only a couple of extra steps: // we can pass any object as context - here create a custom context var context = new CustomContext() { WinForm = this, FirstName = "Rick", Entered = DateTime.Now.AddDays(-10) }; var engine = new RazorEngine<RazorTemplateBase>(); string assId = null; using (StringReader reader = new StringReader(this.txtSource.Text)) { assId = engine.ParseAndCompileTemplate(new string[] { "System.Windows.Forms.dll" }, reader); } string output = engine.RenderTemplateFromAssembly(assId, context); if (output == null) this.txtResult.Text = "*** ERROR:\r\n" + engine.ErrorMessage; else this.txtResult.Text = output; The difference here is that you can capture the assembly – or rather an Id to it – and potentially hold on to it to render again later assuming the template hasn’t changed. The HostContainers take advantage of this feature to cache the assemblies based on certain criteria like a filename and file time step or a string hash that if not change indicate that an assembly can be reused. Note that ParseAndCompileTemplate returns an assembly Id rather than the assembly itself. This is done so that that the assembly always stays in the host’s AppDomain and is not passed across AppDomain boundaries which would cause load failures. We’ll talk more about this in a minute but for now just realize that assemblies references are stored in a list and are accessible by this ID to allow locating and re-executing of the assembly based on that id. Reuse of the assembly avoids recompilation overhead and creation of yet another assembly that loads into the current AppDomain. You can play around with several different versions of the above code in the main sample form: Using Hosting Containers for more Control and Caching The above examples simply render templates into assemblies each and every time they are executed. While this works and is even reasonably fast, it’s not terribly efficient. If you render templates more than once it would be nice if you could cache the generated assemblies for example to avoid re-compiling and creating of a new assembly each time. Additionally it would be nice to load template assemblies into a separate AppDomain optionally to be able to be able to unload assembli es and also to protect your host application from scripting attacks with malicious template code. Hosting containers provide also provide a wrapper around the RazorEngine<T> instance, a factory (which allows creation in separate AppDomains) and an easy way to start and stop the container ‘runtime’. The Razor Hosting samples provide two hosting containers: RazorFolderHostContainer and StringHostContainer. The folder host provides a simple runtime environment for a folder structure similar in the way that the ASP.NET runtime handles a virtual directory as it’s ‘application' root. Templates are loaded from disk in relative paths and the resulting assemblies are cached unless the template on disk is changed. The string host also caches templates based on string hashes – if the same string is passed a second time a cached version of the assembly is used. Here’s how HostContainers work. I’ll use the FolderHostContainer because it’s likely the most common way you’d use templates – from disk based templates that can be easily edited and maintained on disk. The first step is to create an instance of it and keep it around somewhere (in the example it’s attached as a property to the Form): RazorFolderHostContainer Host = new RazorFolderHostContainer(); public RazorFolderHostForm() { InitializeComponent(); // The base path for templates - templates are rendered with relative paths // based on this path. Host.TemplatePath = Path.Combine(Environment.CurrentDirectory, TemplateBaseFolder); // Add any assemblies you want reference in your templates Host.ReferencedAssemblies.Add("System.Windows.Forms.dll"); // Start up the host container Host.Start(); } Next anytime you want to render a template you can use simple code like this: private void RenderTemplate(string fileName) { // Pass the template path via the Context var relativePath = Utilities.GetRelativePath(fileName, Host.TemplatePath); if (!Host.RenderTemplate(relativePath, this.Context, Host.RenderingOutputFile)) { MessageBox.Show("Error: " + Host.ErrorMessage); return; } this.webBrowser1.Navigate("file://" + Host.RenderingOutputFile); } You can also render the output to a string instead of to a file: string result = Host.RenderTemplateToString(relativePath,context); Finally if you want to release the engine and shut down the hosting AppDomain you can simply do: Host.Stop(); Stopping the AppDomain and restarting it (ie. calling Stop(); followed by Start()) is also a nice way to release all resources in the AppDomain. The FolderBased domain also supports partial Rendering based on root path based relative paths with the same caching characteristics as the main templates. From within a template you can call out to a partial like this: @RenderPartial(@"partials\PartialRendering.cshtml", Context) where partials\PartialRendering.cshtml is a relative to the template root folder. The folder host example lets you load up templates from disk and display the result in a Web Browser control which demonstrates using Razor HTML output from templates that contain HTML syntax which happens to me my target scenario for Html Help Builder. The Razor Engine Wrapper Project The project I created to wrap Razor hosting has a fair bit of code and a number of classes associated with it. Most of the components are internally used and as you can see using the final RazorEngine<T> and HostContainer classes is pretty easy. The classes are extensible and I suspect developers will want to build more customized host containers for their applications. Host containers are the key to wrapping up all functionality – Engine, BaseTemplate, AppDomain Hosting, Caching etc in a logical piece that is ready to be plugged into an application. When looking at the code there are a couple of core features provided: Core Razor Engine Hosting This is the core Razor hosting which provides the basics of loading a template, compiling it into an assembly and executing it. This is fairly straightforward, but without a host container that can cache assemblies based on some criteria templates are recompiled and re-created each time which is inefficient (although pretty fast). The base engine wrapper implementation also supports hosting the Razor runtime in a separate AppDomain for security and the ability to unload it on demand. Host Containers The engine hosting itself doesn’t provide any sort of ‘runtime’ service like picking up files from disk, caching assemblies and so forth. So my implementation provides two HostContainers: RazorFolderHostContainer and RazorStringHostContainer. The FolderHost works off a base directory and loads templates based on relative paths (sort of like the ASP.NET runtime does off a virtual). The HostContainers also deal with caching of template assemblies – for the folder host the file date is tracked and checked for updates and unless the template is changed a cached assembly is reused. The StringHostContainer similiarily checks string hashes to figure out whether a particular string template was previously compiled and executed. The HostContainers also act as a simple startup environment and a single reference to easily store and reuse in an application. TemplateBase Classes The template base classes are the base classes that from which the Razor engine generates .NET code. A template is parsed into a class with an Execute() method and the class is based on this template type you can specify. RazorEngine<TBaseTemplate> can receive this type and the HostContainers default to specific templates in their base implementations. Template classes are customizable to allow you to create templates that provide application specific features and interaction from the template to your host application. How does the RazorEngine wrapper work? You can browse the source code in the links above or in the repository or download the source, but I’ll highlight some key features here. Here’s part of the RazorEngine implementation that can be used to host the runtime and that demonstrates the key code required to host the Razor runtime. The RazorEngine class is implemented as a generic class to reflect the Template base class type: public class RazorEngine<TBaseTemplateType> : MarshalByRefObject where TBaseTemplateType : RazorTemplateBase The generic type is used to internally provide easier access to the template type and assignments on it as part of the template processing. The class also inherits MarshalByRefObject to allow execution over AppDomain boundaries – something that all the classes discussed here need to do since there is much interaction between the host and the template. The first two key methods deal with creating a template assembly: /// <summary> /// Creates an instance of the RazorHost with various options applied. /// Applies basic namespace imports and the name of the class to generate /// </summary> /// <param name="generatedNamespace"></param> /// <param name="generatedClass"></param> /// <returns></returns> protected RazorTemplateEngine CreateHost(string generatedNamespace, string generatedClass) { Type baseClassType = typeof(TBaseTemplateType); RazorEngineHost host = new RazorEngineHost(new CSharpRazorCodeLanguage()); host.DefaultBaseClass = baseClassType.FullName; host.DefaultClassName = generatedClass; host.DefaultNamespace = generatedNamespace; host.NamespaceImports.Add("System"); host.NamespaceImports.Add("System.Text"); host.NamespaceImports.Add("System.Collections.Generic"); host.NamespaceImports.Add("System.Linq"); host.NamespaceImports.Add("System.IO"); return new RazorTemplateEngine(host); } /// <summary> /// Parses and compiles a markup template into an assembly and returns /// an assembly name. The name is an ID that can be passed to /// ExecuteTemplateByAssembly which picks up a cached instance of the /// loaded assembly. /// /// </summary> /// <param name="namespaceOfGeneratedClass">The namespace of the class to generate from the template</param> /// <param name="generatedClassName">The name of the class to generate from the template</param> /// <param name="ReferencedAssemblies">Any referenced assemblies by dll name only. Assemblies must be in execution path of host or in GAC.</param> /// <param name="templateSourceReader">Textreader that loads the template</param> /// <remarks> /// The actual assembly isn't returned here to allow for cross-AppDomain /// operation. If the assembly was returned it would fail for cross-AppDomain /// calls. /// </remarks> /// <returns>An assembly Id. The Assembly is cached in memory and can be used with RenderFromAssembly.</returns> public string ParseAndCompileTemplate( string namespaceOfGeneratedClass, string generatedClassName, string[] ReferencedAssemblies, TextReader templateSourceReader) { RazorTemplateEngine engine = CreateHost(namespaceOfGeneratedClass, generatedClassName); // Generate the template class as CodeDom GeneratorResults razorResults = engine.GenerateCode(templateSourceReader); // Create code from the codeDom and compile CSharpCodeProvider codeProvider = new CSharpCodeProvider(); CodeGeneratorOptions options = new CodeGeneratorOptions(); // Capture Code Generated as a string for error info // and debugging LastGeneratedCode = null; using (StringWriter writer = new StringWriter()) { codeProvider.GenerateCodeFromCompileUnit(razorResults.GeneratedCode, writer, options); LastGeneratedCode = writer.ToString(); } CompilerParameters compilerParameters = new CompilerParameters(ReferencedAssemblies); // Standard Assembly References compilerParameters.ReferencedAssemblies.Add("System.dll"); compilerParameters.ReferencedAssemblies.Add("System.Core.dll"); compilerParameters.ReferencedAssemblies.Add("Microsoft.CSharp.dll"); // dynamic support! // Also add the current assembly so RazorTemplateBase is available compilerParameters.ReferencedAssemblies.Add(Assembly.GetExecutingAssembly().CodeBase.Substring(8)); compilerParameters.GenerateInMemory = Configuration.CompileToMemory; if (!Configuration.CompileToMemory) compilerParameters.OutputAssembly = Path.Combine(Configuration.TempAssemblyPath, "_" + Guid.NewGuid().ToString("n") + ".dll"); CompilerResults compilerResults = codeProvider.CompileAssemblyFromDom(compilerParameters, razorResults.GeneratedCode); if (compilerResults.Errors.Count > 0) { var compileErrors = new StringBuilder(); foreach (System.CodeDom.Compiler.CompilerError compileError in compilerResults.Errors) compileErrors.Append(String.Format(Resources.LineX0TColX1TErrorX2RN, compileError.Line, compileError.Column, compileError.ErrorText)); this.SetError(compileErrors.ToString() + "\r\n" + LastGeneratedCode); return null; } AssemblyCache.Add(compilerResults.CompiledAssembly.FullName, compilerResults.CompiledAssembly); return compilerResults.CompiledAssembly.FullName; } Think of the internal CreateHost() method as setting up the assembly generated from each template. Each template compiles into a separate assembly. It sets up namespaces, and assembly references, the base class used and the name and namespace for the generated class. ParseAndCompileTemplate() then calls the CreateHost() method to receive the template engine generator which effectively generates a CodeDom from the template – the template is turned into .NET code. The code generated from our earlier example looks something like this: //------------------------------------------------------------------------------ // <auto-generated> // This code was generated by a tool. // Runtime Version:4.0.30319.1 // // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ namespace RazorTest { using System; using System.Text; using System.Collections.Generic; using System.Linq; using System.IO; using System.Reflection; public class RazorTemplate : RazorHosting.RazorTemplateBase { #line hidden public RazorTemplate() { } public override void Execute() { WriteLiteral("Hello "); Write(Context.FirstName); WriteLiteral("! Your entry was entered on: "); Write(Context.Entered); WriteLiteral("\r\n\r\n"); // Code block: Update the host Windows Form passed in through the context Context.WinForm.Text = "Hello World from Razor at " + DateTime.Now.ToString(); WriteLiteral("\r\nAppDomain Id:\r\n "); Write(AppDomain.CurrentDomain.FriendlyName); WriteLiteral("\r\n \r\nAssembly:\r\n "); Write(Assembly.GetExecutingAssembly().FullName); WriteLiteral("\r\n\r\nCode based output: \r\n"); // Write output with Response object from code string output = string.Empty; for (int i = 0; i < 10; i++) { output += i.ToString() + " "; } } } } Basically the template’s body is turned into code in an Execute method that is called. Internally the template’s Write method is fired to actually generate the output. Note that the class inherits from RazorTemplateBase which is the generic parameter I used to specify the base class when creating an instance in my RazorEngine host: var engine = new RazorEngine<RazorTemplateBase>(); This template class must be provided and it must implement an Execute() and Write() method. Beyond that you can create any class you chose and attach your own properties. My RazorTemplateBase class implementation is very simple: public class RazorTemplateBase : MarshalByRefObject, IDisposable { /// <summary> /// You can pass in a generic context object /// to use in your template code /// </summary> public dynamic Context { get; set; } /// <summary> /// Class that generates output. Currently ultra simple /// with only Response.Write() implementation. /// </summary> public RazorResponse Response { get; set; } public object HostContainer {get; set; } public object Engine { get; set; } public RazorTemplateBase() { Response = new RazorResponse(); } public virtual void Write(object value) { Response.Write(value); } public virtual void WriteLiteral(object value) { Response.Write(value); } /// <summary> /// Razor Parser implements this method /// </summary> public virtual void Execute() {} public virtual void Dispose() { if (Response != null) { Response.Dispose(); Response = null; } } } Razor fills in the Execute method when it generates its subclass and uses the Write() method to output content. As you can see I use a RazorResponse() class here to generate output. This isn’t necessary really, as you could use a StringBuilder or StringWriter() directly, but I prefer using Response object so I can extend the Response behavior as needed. The RazorResponse class is also very simple and merely acts as a wrapper around a TextWriter: public class RazorResponse : IDisposable { /// <summary> /// Internal text writer - default to StringWriter() /// </summary> public TextWriter Writer = new StringWriter(); public virtual void Write(object value) { Writer.Write(value); } public virtual void WriteLine(object value) { Write(value); Write("\r\n"); } public virtual void WriteFormat(string format, params object[] args) { Write(string.Format(format, args)); } public override string ToString() { return Writer.ToString(); } public virtual void Dispose() { Writer.Close(); } public virtual void SetTextWriter(TextWriter writer) { // Close original writer if (Writer != null) Writer.Close(); Writer = writer; } } The Rendering Methods of RazorEngine At this point I’ve talked about the assembly generation logic and the template implementation itself. What’s left is that once you’ve generated the assembly is to execute it. The code to do this is handled in the various RenderXXX methods of the RazorEngine class. Let’s look at the lowest level one of these which is RenderTemplateFromAssembly() and a couple of internal support methods that handle instantiating and invoking of the generated template method: public string RenderTemplateFromAssembly( string assemblyId, string generatedNamespace, string generatedClass, object context, TextWriter outputWriter) { this.SetError(); Assembly generatedAssembly = AssemblyCache[assemblyId]; if (generatedAssembly == null) { this.SetError(Resources.PreviouslyCompiledAssemblyNotFound); return null; } string className = generatedNamespace + "." + generatedClass; Type type; try { type = generatedAssembly.GetType(className); } catch (Exception ex) { this.SetError(Resources.UnableToCreateType + className + ": " + ex.Message); return null; } // Start with empty non-error response (if we use a writer) string result = string.Empty; using(TBaseTemplateType instance = InstantiateTemplateClass(type)) { if (instance == null) return null; if (outputWriter != null) instance.Response.SetTextWriter(outputWriter); if (!InvokeTemplateInstance(instance, context)) return null; // Capture string output if implemented and return // otherwise null is returned if (outputWriter == null) result = instance.Response.ToString(); } return result; } protected virtual TBaseTemplateType InstantiateTemplateClass(Type type) { TBaseTemplateType instance = Activator.CreateInstance(type) as TBaseTemplateType; if (instance == null) { SetError(Resources.CouldnTActivateTypeInstance + type.FullName); return null; } instance.Engine = this; // If a HostContainer was set pass that to the template too instance.HostContainer = this.HostContainer; return instance; } /// <summary> /// Internally executes an instance of the template, /// captures errors on execution and returns true or false /// </summary> /// <param name="instance">An instance of the generated template</param> /// <returns>true or false - check ErrorMessage for errors</returns> protected virtual bool InvokeTemplateInstance(TBaseTemplateType instance, object context) { try { instance.Context = context; instance.Execute(); } catch (Exception ex) { this.SetError(Resources.TemplateExecutionError + ex.Message); return false; } finally { // Must make sure Response is closed instance.Response.Dispose(); } return true; } The RenderTemplateFromAssembly method basically requires the namespace and class to instantate and creates an instance of the class using InstantiateTemplateClass(). It then invokes the method with InvokeTemplateInstance(). These two methods are broken out because they are re-used by various other rendering methods and also to allow subclassing and providing additional configuration tasks to set properties and pass values to templates at execution time. In the default mode instantiation sets the Engine and HostContainer (discussed later) so the template can call back into the template engine, and the context is set when the template method is invoked. The various RenderXXX methods use similar code although they create the assemblies first. If you’re after potentially cashing assemblies the method is the one to call and that’s exactly what the two HostContainer classes do. More on that in a minute, but before we get into HostContainers let’s talk about AppDomain hosting and the like. Running Templates in their own AppDomain With the RazorEngine class above, when a template is parsed into an assembly and executed the assembly is created (in memory or on disk – you can configure that) and cached in the current AppDomain. In .NET once an assembly has been loaded it can never be unloaded so if you’re loading lots of templates and at some time you want to release them there’s no way to do so. If however you load the assemblies in a separate AppDomain that new AppDomain can be unloaded and the assemblies loaded in it with it. In order to host the templates in a separate AppDomain the easiest thing to do is to run the entire RazorEngine in a separate AppDomain. Then all interaction occurs in the other AppDomain and no further changes have to be made. To facilitate this there is a RazorEngineFactory which has methods that can instantiate the RazorHost in a separate AppDomain as well as in the local AppDomain. The host creates the remote instance and then hangs on to it to keep it alive as well as providing methods to shut down the AppDomain and reload the engine. Sounds complicated but cross-AppDomain invocation is actually fairly easy to implement. Here’s some of the relevant code from the RazorEngineFactory class. Like the RazorEngine this class is generic and requires a template base type in the generic class name: public class RazorEngineFactory<TBaseTemplateType> where TBaseTemplateType : RazorTemplateBase Here are the key methods of interest: /// <summary> /// Creates an instance of the RazorHost in a new AppDomain. This /// version creates a static singleton that that is cached and you /// can call UnloadRazorHostInAppDomain to unload it. /// </summary> /// <returns></returns> public static RazorEngine<TBaseTemplateType> CreateRazorHostInAppDomain() { if (Current == null) Current = new RazorEngineFactory<TBaseTemplateType>(); return Current.GetRazorHostInAppDomain(); } public static void UnloadRazorHostInAppDomain() { if (Current != null) Current.UnloadHost(); Current = null; } /// <summary> /// Instance method that creates a RazorHost in a new AppDomain. /// This method requires that you keep the Factory around in /// order to keep the AppDomain alive and be able to unload it. /// </summary> /// <returns></returns> public RazorEngine<TBaseTemplateType> GetRazorHostInAppDomain() { LocalAppDomain = CreateAppDomain(null); if (LocalAppDomain == null) return null; /// Create the instance inside of the new AppDomain /// Note: remote domain uses local EXE's AppBasePath!!! RazorEngine<TBaseTemplateType> host = null; try { Assembly ass = Assembly.GetExecutingAssembly(); string AssemblyPath = ass.Location; host = (RazorEngine<TBaseTemplateType>) LocalAppDomain.CreateInstanceFrom(AssemblyPath, typeof(RazorEngine<TBaseTemplateType>).FullName).Unwrap(); } catch (Exception ex) { ErrorMessage = ex.Message; return null; } return host; } /// <summary> /// Internally creates a new AppDomain in which Razor templates can /// be run. /// </summary> /// <param name="appDomainName"></param> /// <returns></returns> private AppDomain CreateAppDomain(string appDomainName) { if (appDomainName == null) appDomainName = "RazorHost_" + Guid.NewGuid().ToString("n"); AppDomainSetup setup = new AppDomainSetup(); // *** Point at current directory setup.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory; AppDomain localDomain = AppDomain.CreateDomain(appDomainName, null, setup); return localDomain; } /// <summary> /// Allow unloading of the created AppDomain to release resources /// All internal resources in the AppDomain are released including /// in memory compiled Razor assemblies. /// </summary> public void UnloadHost() { if (this.LocalAppDomain != null) { AppDomain.Unload(this.LocalAppDomain); this.LocalAppDomain = null; } } The static CreateRazorHostInAppDomain() is the key method that startup code usually calls. It uses a Current singleton instance to an instance of itself that is created cross AppDomain and is kept alive because it’s static. GetRazorHostInAppDomain actually creates a cross-AppDomain instance which first creates a new AppDomain and then loads the RazorEngine into it. The remote Proxy instance is returned as a result to the method and can be used the same as a local instance. The code to run with a remote AppDomain is simple: private RazorEngine<RazorTemplateBase> CreateHost() { if (this.Host != null) return this.Host; // Use Static Methods - no error message if host doesn't load this.Host = RazorEngineFactory<RazorTemplateBase>.CreateRazorHostInAppDomain(); if (this.Host == null) { MessageBox.Show("Unable to load Razor Template Host", "Razor Hosting", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); } return this.Host; } This code relies on a local reference of the Host which is kept around for the duration of the app (in this case a form reference). To use this you’d simply do: this.Host = CreateHost(); if (host == null) return; string result = host.RenderTemplate( this.txtSource.Text, new string[] { "System.Windows.Forms.dll", "Westwind.Utilities.dll" }, this.CustomContext); if (result == null) { MessageBox.Show(host.ErrorMessage, "Template Execution Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); return; } this.txtResult.Text = result; Now all templates run in a remote AppDomain and can be unloaded with simple code like this: RazorEngineFactory<RazorTemplateBase>.UnloadRazorHostInAppDomain(); this.Host = null; One Step further – Providing a caching ‘Runtime’ Once we can load templates in a remote AppDomain we can add some additional functionality like assembly caching based on application specific features. One of my typical scenarios is to render templates out of a scripts folder. So all templates live in a folder and they change infrequently. So a Folder based host that can compile these templates once and then only recompile them if something changes would be ideal. Enter host containers which are basically wrappers around the RazorEngine<t> and RazorEngineFactory<t>. They provide additional logic for things like file caching based on changes on disk or string hashes for string based template inputs. The folder host also provides for partial rendering logic through a custom template base implementation. There’s a base implementation in RazorBaseHostContainer, which provides the basics for hosting a RazorEngine, which includes the ability to start and stop the engine, cache assemblies and add references: public abstract class RazorBaseHostContainer<TBaseTemplateType> : MarshalByRefObject where TBaseTemplateType : RazorTemplateBase, new() { public RazorBaseHostContainer() { UseAppDomain = true; GeneratedNamespace = "__RazorHost"; } /// <summary> /// Determines whether the Container hosts Razor /// in a separate AppDomain. Seperate AppDomain /// hosting allows unloading and releasing of /// resources. /// </summary> public bool UseAppDomain { get; set; } /// <summary> /// Base folder location where the AppDomain /// is hosted. By default uses the same folder /// as the host application. /// /// Determines where binary dependencies are /// found for assembly references. /// </summary> public string BaseBinaryFolder { get; set; } /// <summary> /// List of referenced assemblies as string values. /// Must be in GAC or in the current folder of the host app/ /// base BinaryFolder /// </summary> public List<string> ReferencedAssemblies = new List<string>(); /// <summary> /// Name of the generated namespace for template classes /// </summary> public string GeneratedNamespace {get; set; } /// <summary> /// Any error messages /// </summary> public string ErrorMessage { get; set; } /// <summary> /// Cached instance of the Host. Required to keep the /// reference to the host alive for multiple uses. /// </summary> public RazorEngine<TBaseTemplateType> Engine; /// <summary> /// Cached instance of the Host Factory - so we can unload /// the host and its associated AppDomain. /// </summary> protected RazorEngineFactory<TBaseTemplateType> EngineFactory; /// <summary> /// Keep track of each compiled assembly /// and when it was compiled. /// /// Use a hash of the string to identify string /// changes. /// </summary> protected Dictionary<int, CompiledAssemblyItem> LoadedAssemblies = new Dictionary<int, CompiledAssemblyItem>(); /// <summary> /// Call to start the Host running. Follow by a calls to RenderTemplate to /// render individual templates. Call Stop when done. /// </summary> /// <returns>true or false - check ErrorMessage on false </returns> public virtual bool Start() { if (Engine == null) { if (UseAppDomain) Engine = RazorEngineFactory<TBaseTemplateType>.CreateRazorHostInAppDomain(); else Engine = RazorEngineFactory<TBaseTemplateType>.CreateRazorHost(); Engine.Configuration.CompileToMemory = true; Engine.HostContainer = this; if (Engine == null) { this.ErrorMessage = EngineFactory.ErrorMessage; return false; } } return true; } /// <summary> /// Stops the Host and releases the host AppDomain and cached /// assemblies. /// </summary> /// <returns>true or false</returns> public bool Stop() { this.LoadedAssemblies.Clear(); RazorEngineFactory<RazorTemplateBase>.UnloadRazorHostInAppDomain(); this.Engine = null; return true; } … } This base class provides most of the mechanics to host the runtime, but no application specific implementation for rendering. There are rendering functions but they just call the engine directly and provide no caching – there’s no context to decide how to cache and reuse templates. The key methods are Start and Stop and their main purpose is to start a new AppDomain (optionally) and shut it down when requested. The RazorFolderHostContainer – Folder Based Runtime Hosting Let’s look at the more application specific RazorFolderHostContainer implementation which is defined like this: public class RazorFolderHostContainer : RazorBaseHostContainer<RazorTemplateFolderHost> Note that a customized RazorTemplateFolderHost class template is used for this implementation that supports partial rendering in form of a RenderPartial() method that’s available to templates. The folder host’s features are: Render templates based on a Template Base Path (a ‘virtual’ if you will) Cache compiled assemblies based on the relative path and file time stamp File changes on templates cause templates to be recompiled into new assemblies Support for partial rendering using base folder relative pathing As shown in the startup examples earlier host containers require some startup code with a HostContainer tied to a persistent property (like a Form property): // The base path for templates - templates are rendered with relative paths // based on this path. HostContainer.TemplatePath = Path.Combine(Environment.CurrentDirectory, TemplateBaseFolder); // Default output rendering disk location HostContainer.RenderingOutputFile = Path.Combine(HostContainer.TemplatePath, "__Preview.htm"); // Add any assemblies you want reference in your templates HostContainer.ReferencedAssemblies.Add("System.Windows.Forms.dll"); // Start up the host container HostContainer.Start(); Once that’s done, you can render templates with the host container: // Pass the template path for full filename seleted with OpenFile Dialog // relativepath is: subdir\file.cshtml or file.cshtml or ..\file.cshtml var relativePath = Utilities.GetRelativePath(fileName, HostContainer.TemplatePath); if (!HostContainer.RenderTemplate(relativePath, Context, HostContainer.RenderingOutputFile)) { MessageBox.Show("Error: " + HostContainer.ErrorMessage); return; } webBrowser1.Navigate("file://" + HostContainer.RenderingOutputFile); The most critical task of the RazorFolderHostContainer implementation is to retrieve a template from disk, compile and cache it and then deal with deciding whether subsequent requests need to re-compile the template or simply use a cached version. Internally the GetAssemblyFromFileAndCache() handles this task: /// <summary> /// Internally checks if a cached assembly exists and if it does uses it /// else creates and compiles one. Returns an assembly Id to be /// used with the LoadedAssembly list. /// </summary> /// <param name="relativePath"></param> /// <param name="context"></param> /// <returns></returns> protected virtual CompiledAssemblyItem GetAssemblyFromFileAndCache(string relativePath) { string fileName = Path.Combine(TemplatePath, relativePath).ToLower(); int fileNameHash = fileName.GetHashCode(); if (!File.Exists(fileName)) { this.SetError(Resources.TemplateFileDoesnTExist + fileName); return null; } CompiledAssemblyItem item = null; this.LoadedAssemblies.TryGetValue(fileNameHash, out item); string assemblyId = null; // Check for cached instance if (item != null) { var fileTime = File.GetLastWriteTimeUtc(fileName); if (fileTime <= item.CompileTimeUtc) assemblyId = item.AssemblyId; } else item = new CompiledAssemblyItem(); // No cached instance - create assembly and cache if (assemblyId == null) { string safeClassName = GetSafeClassName(fileName); StreamReader reader = null; try { reader = new StreamReader(fileName, true); } catch (Exception ex) { this.SetError(Resources.ErrorReadingTemplateFile + fileName); return null; } assemblyId = Engine.ParseAndCompileTemplate(this.ReferencedAssemblies.ToArray(), reader); // need to ensure reader is closed if (reader != null) reader.Close(); if (assemblyId == null) { this.SetError(Engine.ErrorMessage); return null; } item.AssemblyId = assemblyId; item.CompileTimeUtc = DateTime.UtcNow; item.FileName = fileName; item.SafeClassName = safeClassName; this.LoadedAssemblies[fileNameHash] = item; } return item; } This code uses a LoadedAssembly dictionary which is comprised of a structure that holds a reference to a compiled assembly, a full filename and file timestamp and an assembly id. LoadedAssemblies (defined on the base class shown earlier) is essentially a cache for compiled assemblies and they are identified by a hash id. In the case of files the hash is a GetHashCode() from the full filename of the template. The template is checked for in the cache and if not found the file stamp is checked. If that’s newer than the cache’s compilation date the template is recompiled otherwise the version in the cache is used. All the core work defers to a RazorEngine<T> instance to ParseAndCompileTemplate(). The three rendering specific methods then are rather simple implementations with just a few lines of code dealing with parameter and return value parsing: /// <summary> /// Renders a template to a TextWriter. Useful to write output into a stream or /// the Response object. Used for partial rendering. /// </summary> /// <param name="relativePath">Relative path to the file in the folder structure</param> /// <param name="context">Optional context object or null</param> /// <param name="writer">The textwriter to write output into</param> /// <returns></returns> public bool RenderTemplate(string relativePath, object context, TextWriter writer) { // Set configuration data that is to be passed to the template (any object) Engine.TemplatePerRequestConfigurationData = new RazorFolderHostTemplateConfiguration() { TemplatePath = Path.Combine(this.TemplatePath, relativePath), TemplateRelativePath = relativePath, }; CompiledAssemblyItem item = GetAssemblyFromFileAndCache(relativePath); if (item == null) { writer.Close(); return false; } try { // String result will be empty as output will be rendered into the // Response object's stream output. However a null result denotes // an error string result = Engine.RenderTemplateFromAssembly(item.AssemblyId, context, writer); if (result == null) { this.SetError(Engine.ErrorMessage); return false; } } catch (Exception ex) { this.SetError(ex.Message); return false; } finally { writer.Close(); } return true; } /// <summary> /// Render a template from a source file on disk to a specified outputfile. /// </summary> /// <param name="relativePath">Relative path off the template root folder. Format: path/filename.cshtml</param> /// <param name="context">Any object that will be available in the template as a dynamic of this.Context</param> /// <param name="outputFile">Optional - output file where output is written to. If not specified the /// RenderingOutputFile property is used instead /// </param> /// <returns>true if rendering succeeds, false on failure - check ErrorMessage</returns> public bool RenderTemplate(string relativePath, object context, string outputFile) { if (outputFile == null) outputFile = RenderingOutputFile; try { using (StreamWriter writer = new StreamWriter(outputFile, false, Engine.Configuration.OutputEncoding, Engine.Configuration.StreamBufferSize)) { return RenderTemplate(relativePath, context, writer); } } catch (Exception ex) { this.SetError(ex.Message); return false; } return true; } /// <summary> /// Renders a template to string. Useful for RenderTemplate /// </summary> /// <param name="relativePath"></param> /// <param name="context"></param> /// <returns></returns> public string RenderTemplateToString(string relativePath, object context) { string result = string.Empty; try { using (StringWriter writer = new StringWriter()) { // String result will be empty as output will be rendered into the // Response object's stream output. However a null result denotes // an error if (!RenderTemplate(relativePath, context, writer)) { this.SetError(Engine.ErrorMessage); return null; } result = writer.ToString(); } } catch (Exception ex) { this.SetError(ex.Message); return null; } return result; } The idea is that you can create custom host container implementations that do exactly what you want fairly easily. Take a look at both the RazorFolderHostContainer and RazorStringHostContainer classes for the basic concepts you can use to create custom implementations. Notice also that you can set the engine’s PerRequestConfigurationData() from the host container: // Set configuration data that is to be passed to the template (any object) Engine.TemplatePerRequestConfigurationData = new RazorFolderHostTemplateConfiguration() { TemplatePath = Path.Combine(this.TemplatePath, relativePath), TemplateRelativePath = relativePath, }; which when set to a non-null value is passed to the Template’s InitializeTemplate() method. This method receives an object parameter which you can cast as needed: public override void InitializeTemplate(object configurationData) { // Pick up configuration data and stuff into Request object RazorFolderHostTemplateConfiguration config = configurationData as RazorFolderHostTemplateConfiguration; this.Request.TemplatePath = config.TemplatePath; this.Request.TemplateRelativePath = config.TemplateRelativePath; } With this data you can then configure any custom properties or objects on your main template class. It’s an easy way to pass data from the HostContainer all the way down into the template. The type you use is of type object so you have to cast it yourself, and it must be serializable since it will likely run in a separate AppDomain. This might seem like an ugly way to pass data around – normally I’d use an event delegate to call back from the engine to the host, but since this is running over AppDomain boundaries events get really tricky and passing a template instance back up into the host over AppDomain boundaries doesn’t work due to serialization issues. So it’s easier to pass the data from the host down into the template using this rather clumsy approach of set and forward. It’s ugly, but it’s something that can be hidden in the host container implementation as I’ve done here. It’s also not something you have to do in every implementation so this is kind of an edge case, but I know I’ll need to pass a bunch of data in some of my applications and this will be the easiest way to do so. Summing Up Hosting the Razor runtime is something I got jazzed up about quite a bit because I have an immediate need for this type of templating/merging/scripting capability in an application I’m working on. I’ve also been using templating in many apps and it’s always been a pain to deal with. The Razor engine makes this whole experience a lot cleaner and more light weight and with these wrappers I can now plug .NET based templating into my code literally with a few lines of code. That’s something to cheer about… I hope some of you will find this useful as well… Resources The examples and code require that you download the Razor runtimes. Projects are for Visual Studio 2010 running on .NET 4.0 Platform Installer 3.0 (install WebMatrix or MVC 3 for Razor Runtimes) Latest Code in Subversion Repository Download Snapshot of the Code Documentation (CHM Help File) © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET .NET

Search Results

Search found 17407 results on 697 pages for 'static constructor'.

Page 196/697 | < Previous Page | 192 193 194 195 196 197 198 199 200 201 202 203 | Next Page >

- by HH

- by Fraser

- by user2526712

- by davit-datuashvili

- by JL

- by user351565

- by anotherAlan

- by Adnan

- by devoured elysium

- by smwikipedia

- by Newbie

- by Laphroaig

- by ADB

- by davit-datuashvili

- by PJW

- by Narasimham K

- by Coin Bird

- by dowln

- by danx

- by Stephen.Walther

- by psheriff

- by TechTwaddle

- by Kodi Lane

- by Jeff Bridge

- by Rick Strahl

< Previous Page | 192 193 194 195 196 197 198 199 200 201 202 203 | Next Page >