Search Results

Search found 38423 results on 1537 pages for 'try finally'.

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

Page 61/1537 | < Previous Page | 57 58 59 60 61 62 63 64 65 66 67 68  | Next Page >

  • htaccess not working as it should

    - by hsn
    well, ofcourse its not working, im still a n00b :) this is the code that i have : Options +FollowSymLinks RewriteEngine on RewriteRule (.*)\.css - [S=7] RewriteRule (.*)\.jpg - [S=6] RewriteRule ^gallery gallery.html [L] RewriteRule (.*)/(.*)/ index.html?page=$2 [L] RewriteRule (.*)/(.*) index.html?page=$2 [L] RewriteRule (.*)/ index.html?page=$1 [L] RewriteRule (.*) index.html?page=$1 [L,QSA] Now, this works fine, if i try localhost/abc but it wont work if i try localhost/abc/ also, when i try localhost/abc/def (or localhost/abc/def/ for that matter) the css file isnt being included properly. i get an error saying /abc/def/style.css does not exist. :( however, the code doesnt work if i remove the QSA flag from the last rule. this is the code that ive come up with after a lot of googling and reading SO. if anyone can help out i'll be extremely grateful. thanks!

    Read the article

  • Print an EObject ?

    - by tul
    I am writing some eclipse emf code and would like to print the content of an EObject (not store it to disk). Here is what I try: public static void print(EObject obj) { Resource eResource = obj.eResource(); try { eResource.save(System.out, null); } catch (IOException e) { e.printStackTrace(); } } but that gives a NullPointerException. I have tried this instead: public static void print(EObject obj) { ResourceSet resourceSet = new ResourceSetImpl(); resourceSet.getResourceFactoryRegistry().getProtocolToFactoryMap() .put("*", new XMIResourceFactoryImpl()); Resource resource = resourceSet.createResource(URI.createURI("dummyfile.xml")); resource.getContents().add(obj); try { resource.save(System.out, null); } catch (IOException ioe) { ioe.printStackTrace(); } } This works, but is it not possible to print to screen without specifying a dummy URI??

    Read the article

  • I dont understand why [closed]

    - by gcc
    I dont understand why they vote down my question ,I couldont understand them -they do know nothing ,donot try to solve it-but they do vote down.If you do know nothing , dont fuck something or dont try to mess up

    Read the article

  • How do you write a recursive stored procedure

    - by Grayson Mitchell
    I simply want a stored procedure that calculates a unique id and inserts it. If it fails it just calls itself to regenerate said id. I have been looking for an example, but cant find one, and am not sure how I should get the sp to call itself, and set the appropriate output parameter. I would also appreciate someone pointing out how to test this sp also. ALTER PROCEDURE [dbo].[DataContainer_Insert] @SomeData varchar(max), @DataContainerId int out AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SET NOCOUNT ON; BEGIN TRY SELECT @UserId = MAX(UserId) From DataContainer INSERT INTO DataContainer (UserId, SomeData) VALUES (@UserId, SomeData) SELECT @DataContainerId = scope_identity() END TRY BEGIN CATCH --try again exec DataContainer_Insert @DataContainerId, @SomeData END CATCH END

    Read the article

  • reading a random access file

    - by user1067332
    The file I create has text in it, but when i try to read it, the output is null. here is the file the creates the text file, it creates the file and puts it in the right postion import java.util.*; import java.io.*; public class CreateCustomerFile { public static void main(String[] args) throws IOException { int pos; RandomAccessFile it = new RandomAccessFile("CustomerFile.txt", "rw"); Scanner input = new Scanner(System.in); int id; String name; int zip; final int RECORDSIZE = 100; final int NUMRECORDS = 1000; final int STOP = 99; try { for(int x = 0; x < NUMRECORDS; ++x) { it.writeInt(0); it.writeUTF(""); it.writeInt(0); } } catch(IOException e) { System.out.println("Error: " + e.getMessage()); } finally { it.close(); } it = new RandomAccessFile("CustomerFile.txt","rw"); try { System.out.print("Enter ID number" + " or " + STOP + " to quit "); id = input.nextInt(); while(id != STOP) { input.nextLine(); System.out.print("Enter last name"); name = input.nextLine(); System.out.print("Enter zipcode "); zip = input.nextInt(); pos = id - 1; it.seek(pos * RECORDSIZE); it.writeInt(id); it.writeUTF(name); it.writeInt(zip); System.out.print("Enter ID number" + " or " + STOP + " to quit "); id = input.nextInt(); } } catch(IOException e) { System.out.println("Error: " + e.getMessage()); } finally { it.close(); } } } Here is the file to read, the pos is correct but ouput always goes to the error: null. import javax.swing.*; import java.io.*; public class CustomerItemOrder { public static void main(String[] args) throws IOException { int pos; RandomAccessFile it = new RandomAccessFile("CustomerFile.txt","rw"); String inputString; int id, zip; String name; final int RECORDSIZE = 100; final int STOP = 99; inputString = JOptionPane.showInputDialog(null, "Enter id or "+ STOP + " to quit"); id = Integer.parseInt(inputString); try { while(id != STOP) { pos = id -1 ; it.seek(pos * RECORDSIZE ); id = it.readInt(); name = it.readLine(); zip = it.readInt(); JOptionPane.showMessageDialog(null, "ID:" + id + " last name is " + name + " and zipcode is " + zip); inputString = JOptionPane.showInputDialog(null, "Enter id or " + STOP + " to quit"); id = Integer.parseInt(inputString); } } catch(IOException e) { System.out.println("Error: " + e.getMessage()); } finally { it.close(); } } }

    Read the article

  • Windows 7 booting and startup repair issues

    - by aardvark
    I have a MSI FR720 laptop with Windows 7 and Lubuntu partions. For quite a while (6 months or so) I've been having issues booting from my hard drive, it'd take me between 5 minutes and several hours for me to be able to have it recognize the hard drive as a bootable device. I did several disk checks on it, and my hard drive seems in perfect condition, and the fact that booting would usually only work after removing the hard drive and trying to reset it in its slot or lightly shaking it makes me think it had something to do with the connection in the hard drive slot as opposed to the hard drive itself. I was having particular issues with it detecting the hard drive today so I decided to try booting it from an external hard drive dock. It detected it first try and so far has had no problems finding the bootable partitions on my hard drive. When I selected my Windows 7 partition from the boot menu it said that it hadn't been shut down properly last time and needed startup repair. I've done this several times over the last 6 months, so this is hardly unusual. I do startup repair, it fails, and then I try to do a system restore. The system restore also failed, and it says that no files were changed. I restart and try it again. However, this time when I get to the startup repair it's not detecting a Windows OS. I tried clicking next and doing a startup repair but the repair is always failing. If I ignore the startup repair option and instead select "Launch windows normally" it will get to the windows animation, stop halfway through and then crash into a BSoD. I can't read the error on the screen because it immediately switches to back and tries to restart. This is my first time asking a question like this online, so let me know if I need to provide any extra information and I'll do my best to give it I tried using diskpart to find the list of partitions and see if one's labelled as an active partition, but it says that no disk were detected. I can run Lubuntu just fine. I can also see all of my Windows 7 files from it EDIT: The startup repair diagnosis and repair log is this: -- Number of repair attempts: 1 Session details System Disk = Windows directory = AutoChk Run = 0 Number of root causes = 1 Test Performed: Name: Check for updates Result: Completed successfully. Error code = 0x0 Time taken = 15ms Test Performed: Name: System disk test Result: Completed successfully. Error code = 0x0 Time taken = 31ms Root cause found. If a hard disk is installed, it is not responding. -- Any chance that this is a result of me doing this through an external dock through a USB drive?

    Read the article

  • Android emulator-5554 offline

    - by hanesjw
    I'm having a problem with emulator-5554, it keeps telling me it is offline. When I do a 'adb devices' from the command line it says emulator-5554 offline Even after a fresh restart, I try that command and it still says it is offline. The problem is when I try to install .apk files to the emulator using 'abd install path' from the command prompt, it tells me that it is offline, if I create another device and run that one, then try to install the .apk files, it says i have too many devices connected. So in other words, I can't install my .apk files. How in the world can I get rid of that damn emulator-5554? I heard that if you do a restart, it should clear all the devices, but that does not seem to be working. It is like it is getting initialized when my computer starts up. Has anyone run into this issue? Thanks

    Read the article

  • send datas to php with ajax - Internal Server Error(500)

    - by user1277467
    i try to send my datas to php with ajax but there's strange mistake. this is my ajax script, function deleteData2() { var artistIds = new Array(); $(".p16 input:checked").each(function(){ artistIds.push($(this).attr('id')); }); $.post('/json/crewonly/deleteDataAjax2', { json: JSON.stringify({'artistIds': artistIds}) }, function(response){ alert(response); }); } i think this works correctly but in php side, i face 500 internal server error(500). public function deleteDataAjax2() { $json = $_POST['json']; $data = json_decode($json); $artistIds = $data['artistIds']; $this->sendJSONResponse($artistIds); } Above code is my php. For example, when i try to send $data to ajax, i print my ids in json mode: However, when i try to send $artistIds to ajax side, i gives 500 error why?

    Read the article

  • Create Static Library iOS Error

    - by bit-whacker
    This is FIrst time i try to create Cocoa Touch Static Library and follow these steps. Create New Project with Cocoa Touch Static Library named it By default i got single class with Demo.h and Demo.m. 2.Create a public function in .h and implement it in .m. 3.Select iOS Device and press cmd + B. 4.Copy Demo.a from products and the .h file drop it in my iOS App where i want to use it. 5.Then Import Demo.h and try to call the function that i wrote. Issue When try to Run the project showing this error. ld: warning: ignoring file /Users/Zenga/Documents/iOS/Static Library/myAppwithLib/Demo.a, file was built for archive which is not the architecture being linked (i386): /Users/Zenga/Documents/iOS/Static Library/myAppwithLib/Demo.a Undefined symbols for architecture i386: "_OBJC_CLASS_$_Demo", referenced from: objc-class-ref in ViewController.o ld: symbol(s) not found for architecture i386 clang: error: linker command failed with exit code 1 (use -v to see invocation) Please help if anyone have any idea about it.

    Read the article

  • Apache crashes after installing mysqli

    - by Marco P.
    System: Apache 2.2 running on Windows 2008 Server with PHP 5.2.17 VC6 Thread-Safe as a Module and MySQL 5.5.17 - all working fine. After installing mysqli using the php package, Apache won't start anymore. There is no error message in the log. What I have tried: Make sure Windows PATH points to libmysql.dll: Yes, done. Make sure extension_dir points to the right point: Yes. Other extensions load fine. Try without mysqli: Yes, Apache loads fine then. Try without mysql: Yes, does not help. Test mysql itself: Restarts server! Overwrite libmysql: Yes, does not help. It seems to me that there is some general problem with MySql, but the DB server seems to be running fine. I'm really out of ideas of things I could try, so I'm desperate for any hints or tricks.

    Read the article

  • How can I compare two jpeg encoding and other inormations

    - by Subhen
    We have created a Driver programe which connect to a remote host using FTP and mount the remote host as a network drive. So when I try to copy some data it copies using FTP retrieve request and then paste it to the destination. The copy paste works fine as we can see the source file size and destination size are same. But while we try to open the .jpg file that is being copied , says no preview. I suspect there must be some bytes that is being corrupted while we try to copy and paste. Is there any tools so that I can compare both source and destination to get the differences.

    Read the article

  • Fail to resolve a name when calling ConnMgrEstablishConnectionSync()

    - by Rodriguez
    Hi Guys, I'm trying to setup a GPRS connection with ConnMgrEstablishConnectionSync(), so far so good, the connection is established and if I try to connect to an IP address, everything works fine. Alas, when I try to resolve a name: ConnMgrEstablishConnectionSync(); ... gethostbyname("www.google.com"); The result is always an error: 0x00002af9 (host not found). Therefor I'm not able to resolve any name, but if I try to open a browser, the browser is able to resolve everything. Am I doing something wrong? Thanx for your help.

    Read the article

  • Need help making this code more efficient

    - by Rendicahya
    I always use this method to easily read the content of a file. Is it efficient enough? Is 1024 good for the buffer size? public static String read(File file) { FileInputStream stream = null; StringBuilder str = new StringBuilder(); try { stream = new FileInputStream(file); } catch (FileNotFoundException e) { } FileChannel channel = stream.getChannel(); ByteBuffer buffer = ByteBuffer.allocate(1024); try { while (channel.read(buffer) != -1) { buffer.flip(); while (buffer.hasRemaining()) { str.append((char) buffer.get()); } buffer.rewind(); } } catch (IOException e) { } finally { try { channel.close(); stream.close(); } catch (IOException e) { } } return str.toString(); }

    Read the article

  • best practice for Jquery plugin implementation and resource locations

    - by ptutt
    This is probably a very basic question, but I seem to have issues plugging in jquery plug-ins. The issue seems to be around the location of the script, css and images and ensuring the css has the correct url to the images. The standard plug-in has the following folder structure (eg : JPicker) js css images My project is asp.net mvc so I have the default: scripts images content So, I try to split the jquery plugin to the appropriate folders (not sure if this is the best way?). Then I try to correct the references to images (background urls) in the css. I believe the url is relative to the page that is implementing the css file, not the location of the css file itself. Anyway, when I try the above, the plugins don't seem to work. I believe the issue lies with the images not being found. The jquery code runs without errors, so I assume that's not the problem. Any help/advice much appreciated

    Read the article

  • c# xml function to check whether a string is equal to a xml attribute, to add selected combobox item

    - by fuch
    i want to check the combobox.selecteditem.tostring() on combobox select in a given xml with several nodes, where each one has an attribute called "name" private void comboBox1_SelectedIndexChanged(object sender, EventArgs e) { try { textBox1.AppendText(nameAttributeCheck(comboBox1.SelectedItem.ToString())); } catch { } } private string nameAttributeCheck(string a) { XmlDocument doc = new XmlDocument(); doc.Load("armor.xml"); XmlElement root = doc.DocumentElement; XmlNodeList items = root.SelectNodes("/items"); String result = null; try { foreach (XmlNode item in items) { if (string.Equals(a, item.Attributes["name"].InnerText.ToString())) { result += item.Attributes["picture"].InnerText.ToString(); } } } catch { } return result; } each time i try it, nothing happens

    Read the article

  • Doesn't get the output in Java Database Connectivity

    - by Dooree
    I'm working on Java Database Connectivity through Eclipse IDE. I built a database through Ubuntu Terminal, and I need to connect and work with it. However, when I tried to run the following code, I don't get any error, but the following output is showed, anybody knows why I don't get the output from the code ? //STEP 1. Import required packages import java.sql.*; public class FirstExample { // JDBC driver name and database URL static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; static final String DB_URL = "jdbc:mysql://localhost/EMP"; // Database credentials static final String USER = "username"; static final String PASS = "password"; public static void main(String[] args) { Connection conn = null; Statement stmt = null; try{ //STEP 2: Register JDBC driver Class.forName("com.mysql.jdbc.Driver"); //STEP 3: Open a connection System.out.println("Connecting to database..."); conn = DriverManager.getConnection(DB_URL,USER,PASS); //STEP 4: Execute a query System.out.println("Creating statement..."); stmt = conn.createStatement(); String sql; sql = "SELECT id, first, last, age FROM Employees"; ResultSet rs = stmt.executeQuery(sql); //STEP 5: Extract data from result set while(rs.next()){ //Retrieve by column name int id = rs.getInt("id"); int age = rs.getInt("age"); String first = rs.getString("first"); String last = rs.getString("last"); //Display values System.out.print("ID: " + id); System.out.print(", Age: " + age); System.out.print(", First: " + first); System.out.println(", Last: " + last); } //STEP 6: Clean-up environment rs.close(); stmt.close(); conn.close(); }catch(SQLException se){ //Handle errors for JDBC se.printStackTrace(); }catch(Exception e){ //Handle errors for Class.forName e.printStackTrace(); }finally{ //finally block used to close resources try{ if(stmt!=null) stmt.close(); }catch(SQLException se2){ }// nothing we can do try{ if(conn!=null) conn.close(); }catch(SQLException se){ se.printStackTrace(); }//end finally try }//end try System.out.println("Goodbye!"); }//end main }//end FirstExample <ConnectionProperties> <PropertyCategory name="Connection/Authentication"> <Property name="user" required="No" default="" sortOrder="-2147483647" since="all"> The user to connect as </Property> <Property name="password" required="No" default="" sortOrder="-2147483646" since="all"> The password to use when connecting </Property> <Property name="socketFactory" required="No" default="com.mysql.jdbc.StandardSocketFactory" sortOrder="4" since="3.0.3"> The name of the class that the driver should use for creating socket connections to the server. This class must implement the interface 'com.mysql.jdbc.SocketFactory' and have public no-args constructor. </Property> <Property name="connectTimeout" required="No" default="0" sortOrder="9" since="3.0.1"> Timeout for socket connect (in milliseconds), with 0 being no timeout. Only works on JDK-1.4 or newer. Defaults to '0'. </Property> ...

    Read the article

  • response from server

    - by john
    When I create request to the server: <script language="javascript" type="text/javascript"> function ajaxFunction() var ajaxRequest; try{ ajaxRequest = new XMLHttpRequest(); } catch (e){ try{ } catch (e) { try{ ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP"); } catch (e){ alert("Your browser broke!"); return false; } } } ajaxRequest.onreadystatechange = function(){ if(ajaxRequest.readyState == 4){ document.write(ajaxRequest.responseText); document.myForm.time.value = ajaxRequest.responseText; } } ajaxRequest.open("GET", "http://www.bbc.co.uk", true); ajaxRequest.send(null); } </script> Why response is nothing? Why response isnt html code of this web site?

    Read the article

  • Real Excel Templates I

    - by Tim Dexter
    As promised, I'm starting to document the new Excel templates that I teased you all with a few weeks back. Leslie is buried in 11g documentation and will not get to officially documenting the templates for a while. I'll do my best to be professional and not ramble on about this and that, although the weather here has finally turned and its 'scorchio' here in Colorado today. Maybe our stand of Aspen will finally come into leaf ... but I digress. Preamble These templates are not actually that new, I helped in a small way to develop them a few years back with Excel 'meistress' Shirley for a company that was trying to use the Report Manager(RR) Excel FSG outputs under EBS 12. The functionality they needed was just not there in the RR FSG templates, the templates are actually XSL that is created from the the RR Excel template builder and fed to BIP for processing. Think of Excel from our RTF templates and you'll be there ie not really Excel but HTML masquerading as Excel. Although still under controlled release in EBS they have now made their way to the standlone release and are willing to share their Excel goodness. You get everything you have with hte Excel Analyzer Excel templates plus so much more. Therein lies a question, what will happen to the Analyzer templates? My understanding is that both will come together into a single Excel template format some time in the post-11g release world. The new XLSX format for Exce 2007/10 is also in the mix too so watch this space. What more do these templates offer? Well, you can structure data in the Excel output. Similar to RTF templates you can create sheets of data that have master-detail n relationships. Although the analyzer templates can do this, you have to get into macros whereas BIP will do this all for you. You can also use native XSL functions in your data to manipulate it prior to rendering. BP functions are not currently supported. The most impressive, for me at least, is the sheet 'bursting'. You can split your hierarchical data across multiple sheets and dynamically name those sheets. Finally, you of course, still get all the native Excel functionality. Pre-reqs You must be on 10.1.3.4.1 plus the latest rollup patch, 9546699. You can patch upa BIP instance running with OBIEE, no problem You need Excel 2000 or above to build the templates Some patience - there is no Excel template builder for these new templates. So its all going to have to be done by hand. Its not that tough but can get a little 'fiddly'. You can not test the template from Excel , it has to be deployed and then run. Limitations The new templates are definitely superior to the Analyzer templates but there are a few limitations. Re-grouping is not supported. You can only follow a data hierarchy not bend it to your will unless you want to get into macros. No support for BIP functions. The templates support native XSL functions only. No template builder Getting Started The templates make the use of named cells and groups of cells to allow BIP to find the insertion point for data points. It also uses a hidden sheet to store calculation mappings from named cells to XML data elements. To start with, in the great BIP tradition, we need some sample XML data. Becasue I wanted to show the master-detail output we need some hierarchical data. If you have not yet gotten into the data templates, now is a good time, I wrote a post a while back starting from the simple to more complex. They generate ideal data sets for these templates. Im working with the following data set: <EMPLOYEES> <LIST_G_DEPT> <G_DEPT> <DEPARTMENT_ID>10</DEPARTMENT_ID> <DEPARTMENT_NAME>Administration</DEPARTMENT_NAME> <LIST_G_EMP> <G_EMP> <EMPLOYEE_ID>200</EMPLOYEE_ID> <EMP_NAME>Jennifer Whalen</EMP_NAME> <EMAIL>JWHALEN</EMAIL> <PHONE_NUMBER>515.123.4444</PHONE_NUMBER> <HIRE_DATE>1987-09-17T00:00:00.000-06:00</HIRE_DATE> <SALARY>4400</SALARY> </G_EMP> </LIST_G_EMP> <TOTAL_EMPS>1</TOTAL_EMPS> <TOTAL_SALARY>4400</TOTAL_SALARY> <AVG_SALARY>4400</AVG_SALARY> <MAX_SALARY>4400</MAX_SALARY> <MIN_SALARY>4400</MIN_SALARY> </G_DEPT> ... <LIST_G_DEPT> <EMPLOYEES> Simple enough to follow and bread and butter stuff for an RTF template. Building the Template For an Excel template we need to start by thinking about how we want to render the data. Come up with a sample output in Excel. Its all dummy data, nothing marked up yet with one row of data for each level. I have the department name and then a repeating row for the employees. You can apply Excel formatting to the layout. The total is going to be derived from a data element. We'll get to Excel functions later. Marking Up Cells Next we need to start marking up the cells with custom names to map them to data elements. The cell names need to follow a specific format: For data grouping, XDO_GROUP_?group_name? For data elements, XDO_?element_name? Notice the question mark delimter, the group_name and element_name are case sensitive. The next step is to find how to name cells; the easiest method is to highlight the cell and then type in the name. You can also find the Name Manager dialog. I use 2007 and its available on the ribbon under the Formulas section Go thorugh the process of naming all the cells for the element values you have. Using my data set from above.You should end up with something like this in your 'Name Manager' dialog. You can update any mistakes you might have made through this dialog. Creating Groups In the image above you can see there are a couple of named group cells. To create these its a simple case of highlighting the cells that make up the group and then naming them. For the EMP group, highlight the employee row and then type in the name, XDO_GROUP?G_EMP? Notice the 10,000 total is outside of the G_EMP group. Its actually named, XDO_?TOTAL_SALARY?, a query calculated value. For the department group, we need to include the department name cell and the sub EMP grouping and name it, XDO_GROUP?G_DEPT? Notice, the 10,000 total is included in the G_DEPT group. This will ensure it repeats at the department level. Lastly, we do need to include a special sheet in the workbook. We will not have anything meaningful in there for now, but it needs to be present. Create a new sheet and name it XDO_METADATA. The name is important as the BIP rendering engine will looking for it. For our current example we do not need anything other than the required stuff in our XDO_METADATA sheet but, it must be present. Easy enough to hide it. Here's what I have: The only cell that is important is the 'Data Constraints:' cell. The rest is optional. To save curious users getting distracted, hide the metadata sheet. Deploying & Running Templates We should now have a usable Excel template. Loading it into a report is easy enough using the browser UI, just like an RTF template. Set the template type to Excel. You will now be able to run the report and hopefully get something like this. You will not get the red highlighting, thats just some conditional formatting I added to the template using Excel functionality. Your dates are probably going to look raw too. I got around this for now using an Excel function on the cell: =--REPLACE(SUBSTITUTE(E8,"T"," "),LEN(E8)-6,6,"") Google to the rescue on that one. Try some other stuff out. To avoid constantly loading the template through the UI. If you have BIP running locally or you can access the reports repository, once you have loaded the template the first time. Just save the template directly into the report folder. I have put together a sample report using a sample data set, available here. Just drop the xml data file, EmpbyDeptExcelData.xml into 'demo files' folder and you should be good to go. Thats the basics, next we'll start using some XSL functions in the template and move onto the 'bursting' across sheets.

    Read the article

  • HTML5 Form Validation

    - by Stephen.Walther
    The latest versions of Google Chrome (16+), Mozilla Firefox (8+), and Internet Explorer (10+) all support HTML5 client-side validation. It is time to take HTML5 validation seriously. The purpose of the blog post is to describe how you can take advantage of HTML5 client-side validation regardless of the type of application that you are building. You learn how to use the HTML5 validation attributes, how to perform custom validation using the JavaScript validation constraint API, and how to simulate HTML5 validation on older browsers by taking advantage of a jQuery plugin. Finally, we discuss the security issues related to using client-side validation. Using Client-Side Validation Attributes The HTML5 specification discusses several attributes which you can use with INPUT elements to perform client-side validation including the required, pattern, min, max, step, and maxlength attributes. For example, you use the required attribute to require a user to enter a value for an INPUT element. The following form demonstrates how you can make the firstName and lastName form fields required: <!DOCTYPE html> <html > <head> <title>Required Demo</title> </head> <body> <form> <label> First Name: <input required title="First Name is Required!" /> </label> <label> Last Name: <input required title="Last Name is Required!" /> </label> <button>Register</button> </form> </body> </html> If you attempt to submit this form without entering a value for firstName or lastName then you get the validation error message: Notice that the value of the title attribute is used to display the validation error message “First Name is Required!”. The title attribute does not work this way with the current version of Firefox. If you want to display a custom validation error message with Firefox then you need to include an x-moz-errormessage attribute like this: <input required title="First Name is Required!" x-moz-errormessage="First Name is Required!" /> The pattern attribute enables you to validate the value of an INPUT element against a regular expression. For example, the following form includes a social security number field which includes a pattern attribute: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Pattern</title> </head> <body> <form> <label> Social Security Number: <input required pattern="^d{3}-d{2}-d{4}$" title="###-##-####" /> </label> <button>Register</button> </form> </body> </html> The regular expression in the form above requires the social security number to match the pattern ###-##-####: Notice that the input field includes both a pattern and a required validation attribute. If you don’t enter a value then the regular expression is never triggered. You need to include the required attribute to force a user to enter a value and cause the value to be validated against the regular expression. Custom Validation You can take advantage of the HTML5 constraint validation API to perform custom validation. You can perform any custom validation that you need. The only requirement is that you write a JavaScript function. For example, when booking a hotel room, you might want to validate that the Arrival Date is in the future instead of the past: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Constraint Validation API</title> </head> <body> <form> <label> Arrival Date: <input id="arrivalDate" type="date" required /> </label> <button>Submit Reservation</button> </form> <script type="text/javascript"> var arrivalDate = document.getElementById("arrivalDate"); arrivalDate.addEventListener("input", function() { var value = new Date(arrivalDate.value); if (value < new Date()) { arrivalDate.setCustomValidity("Arrival date must be after now!"); } else { arrivalDate.setCustomValidity(""); } }); </script> </body> </html> The form above contains an input field named arrivalDate. Entering a value into the arrivalDate field triggers the input event. The JavaScript code adds an event listener for the input event and checks whether the date entered is greater than the current date. If validation fails then the validation error message “Arrival date must be after now!” is assigned to the arrivalDate input field by calling the setCustomValidity() method of the validation constraint API. Otherwise, the validation error message is cleared by calling setCustomValidity() with an empty string. HTML5 Validation and Older Browsers But what about older browsers? For example, what about Apple Safari and versions of Microsoft Internet Explorer older than Internet Explorer 10? What the world really needs is a jQuery plugin which provides backwards compatibility for the HTML5 validation attributes. If a browser supports the HTML5 validation attributes then the plugin would do nothing. Otherwise, the plugin would add support for the attributes. Unfortunately, as far as I know, this plugin does not exist. I have not been able to find any plugin which supports both the required and pattern attributes for older browsers, but does not get in the way of these attributes in the case of newer browsers. There are several jQuery plugins which provide partial support for the HTML5 validation attributes including: · jQuery Validation — http://docs.jquery.com/Plugins/Validation · html5Form — http://www.matiasmancini.com.ar/jquery-plugin-ajax-form-validation-html5.html · h5Validate — http://ericleads.com/h5validate/ The jQuery Validation plugin – the most popular JavaScript validation library – supports the HTML5 required attribute, but it does not support the HTML5 pattern attribute. Likewise, the html5Form plugin does not support the pattern attribute. The h5Validate plugin provides the best support for the HTML5 validation attributes. The following page illustrates how this plugin supports both the required and pattern attributes: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>h5Validate</title> <style type="text/css"> .validationError { border: solid 2px red; } .validationValid { border: solid 2px green; } </style> </head> <body> <form id="customerForm"> <label> First Name: <input id="firstName" required /> </label> <label> Social Security Number: <input id="ssn" required pattern="^d{3}-d{2}-d{4}$" title="Expected pattern is ###-##-####" /> </label> <input type="submit" /> </form> <script type="text/javascript" src="Scripts/jquery-1.4.4.min.js"></script> <script type="text/javascript" src="Scripts/jquery.h5validate.js"></script> <script type="text/javascript"> // Enable h5Validate plugin $("#customerForm").h5Validate({ errorClass: "validationError", validClass: "validationValid" }); // Prevent form submission when errors $("#customerForm").submit(function (evt) { if ($("#customerForm").h5Validate("allValid") === false) { evt.preventDefault(); } }); </script> </body> </html> When an input field fails validation, the validationError CSS class is applied to the field and the field appears with a red border. When an input field passes validation, the validationValid CSS class is applied to the field and the field appears with a green border. From the perspective of HTML5 validation, the h5Validate plugin is the best of the plugins. It adds support for the required and pattern attributes to browsers which do not natively support these attributes such as IE9. However, this plugin does not include everything in my wish list for a perfect HTML5 validation plugin. Here’s my wish list for the perfect back compat HTML5 validation plugin: 1. The plugin would disable itself when used with a browser which natively supports HTML5 validation attributes. The plugin should not be too greedy – it should not handle validation when a browser could do the work itself. 2. The plugin should simulate the same user interface for displaying validation error messages as the user interface displayed by browsers which natively support HTML5 validation. Chrome, Firefox, and Internet Explorer all display validation errors in a popup. The perfect plugin would also display a popup. 3. Finally, the plugin would add support for the setCustomValidity() method and the other methods of the HTML5 validation constraint API. That way, you could implement custom validation in a standards compatible way and you would know that it worked across all browsers both old and new. Security It would be irresponsible of me to end this blog post without mentioning the issue of security. It is important to remember that any client-side validation — including HTML5 validation — can be bypassed. You should use client-side validation with the intention to create a better user experience. Client validation is great for providing a user with immediate feedback when the user is in the process of completing a form. However, client-side validation cannot prevent an evil hacker from submitting unexpected form data to your web server. You should always enforce your validation rules on the server. The only way to ensure that a required field has a value is to verify that the required field has a value on the server. The HTML5 required attribute does not guarantee anything. Summary The goal of this blog post was to describe the support for validation contained in the HTML5 standard. You learned how to use both the required and the pattern attributes in an HTML5 form. We also discussed how you can implement custom validation by taking advantage of the setCustomValidity() method. Finally, I discussed the available jQuery plugins for adding support for the HTM5 validation attributes to older browsers. Unfortunately, I am unaware of any jQuery plugin which provides a perfect solution to the problem of backwards compatibility.

    Read the article

  • In Which We Demystify A Few Docupresentment Settings And Learn the Ethos of the Author

    - by Andy Little
    It's no secret that Docupresentment (part of the Oracle Documaker suite) is powerful tool for integrating on-demand and interactive applications for publishing with the Oracle Documaker framework.  It's also no secret there are are many details with respect to the configuration of Docupresentment that can elude even the most erudite of of techies.  To be sure, Docupresentment will work for you right out of the box, and in most cases will suit your needs without toying with a configuration file.  But, where's the adventure in that?   With this inaugural post to That's The Way, I'm going to introduce myself, and what my aim is with this blog.  If you didn't figure it out already by checking out my profile, my name is Andy and I've been with Oracle (nee Skywire Software nee Docucorp nee Formmaker) since the formative years of 1998.  Strangely, it doesn't seem that long ago, but it's certainly a lifetime in the age of technology.  I recall running a BBS from my parent's basement on a 1200 baud modem, and the trepidation and sweaty-palmed excitement of upgrading to the power and speed of 2400 baud!  Fine, I'll admit that perhaps I'm inflating the experience a bit, but I was kid!  This is the stuff of War Games and King's Quest I and the demise of TI-99 4/A.  Exciting times.  So fast-forward a bit and I'm 12 years into a career in the world of document automation and publishing working for the best (IMHO) software company on the planet.  With That's The Way I hope to shed a little light and peek under the covers of some of the more interesting aspects of implementations involving the tech space within the Oracle Insurance Global Business Unit (IGBU), which includes Oracle Documaker, Rating & Underwriting, and Policy Administration to name a few.  I may delve off course a bit, and you'll likely get a dose of humor (at least in my mind) but I hope you'll glean at least a tidbit of usefulness with each post.  Feel free to comment as I'm a fairly conversant guy and happy to talk -- it's stopping the talking that's the hard part... So, back to our regularly-scheduled post, already in progress.  By this time you've visited Oracle's E-Delivery site and acquired your properly-licensed version of Oracle Documaker.  Wait -- you didn't find it?  Understandable -- navigating the voluminous download library within Oracle can be a daunting task.  It's pretty simple once you’ve done it a few times.  Login to the e-delivery site, and accept the license terms and restrictions.  Then, you’ll be able to select the Oracle Insurance Applications product pack and your appropriate platform. Click Go and you’ll see a list of applicable products, and you’ll click on Oracle Documaker Media Pack (as I went to press with this article the version is 11.4): Finally, click the Download button next to Docupresentment (again, version at press time is 2.2 p5). This should give you a ZIP file that contains the installation packages for the Docupresentment Server and Client, cryptically named IDSServer22P05W32.exe and IDSClient22P05W32.exe. At this time, I’d like to take a little detour and explain that the world of Oracle, like most technical companies, is rife with acronyms.  One of the reasons Skywire Software was a appealing to Oracle was our use of many acronyms, including the occasional use of multiple acronyms with the same meaning.  I apologize in advance and will try to point these out along the way.  Here’s your first sticky note to go along with that: IDS = Internet Document Server = Docupresentment Once you’ve completed the installation, you’ll have a shiny new Docupresentment server and client, and if you installed the default location it will be living in c:\docserv. Unix users, I’m one of you!  You’ll find it by default in  ~/docupresentment/docserv.  Forging onward with the meat of this post is learning about some special configuration options.  By now you’ve read the documentation included with the download (specifically ids_book.pdf) which goes into some detail of the rubric of the configuration file and in fact there’s even a handy utility that provides an interface to the configuration file (see Running IDSConfig in the documentation).  But who wants to deal with a configuration utility when we have the tools and technology to edit the file <gasp> by hand! I shall now proceed with the standard Information Technology Under the Hood Disclaimer: Please remember to back up any files before you make changes.  I am not responsible for any havoc you may wreak! Go to your installation directory, and locate your docserv.xml file.  Open it in your favorite XML editor.  I happen to be fond of Notepad++ with the XML Tools plugin.  Almost immediately you will behold the splendor of the configuration file.  Just take a moment and let that sink in.  Ok – moving on.  If you reviewed the documentation you know that inside the root <configuration> node there are multiple <section> nodes, each containing a specific group of settings.  Let’s take a look at <section name=”DocumentServer”>: There are a few entries I’d like to discuss.  First, <entry name=”StartCommand”>. This should be pretty self-explanatory; it’s the name of the executable that’s run when you fire up Docupresentment.  Immediately following that is <entry name=”StartArguments”> and as you might imagine these are the arguments passed to the executable.  A few things to point out: The –Dids.configuration=docserv.xml parameter specifies the name of your configuration file. The –Dlogging.configuration=logconf.xml parameter specifies the name of your logging configuration file (this uses log4j so bone up on that before you delve here). The -Djava.endorsed.dirs=lib/endorsed parameter specifies the path where 3rd party Java libraries can be located for use with Docupresentment.  More on that in another post. The <entry name=”Instances”> allows you to specify the number of instances of Docupresentment that will be started.  By default this is two, and generally two instances per CPU is adequate, however you will always need to perform load testing to determine the sweet spot based on your hardware and types of transactions.  You may have many, many more instances than 2. Time for a sidebar on instances.  An instance is nothing more than a separate process of Docupresentment.  The Docupresentment service that you fire up with docserver.bat or docserver.sh actually starts a watchdog process, which is then responsible for starting up the actual Docupresentment processes.  Each of these act independently from one another, so if one crashes, it does not affect any others.  In the case of a crashed process, the watchdog will start up another instance so the number of configured instances are always running.  Bottom line: instance = Docupresentment process. And now, finally, to the settings which gave me pause on an not-too-long-ago implementation!  Docupresentment includes a feature that watches configuration files (such as docserv.xml and logconf.xml) and will automatically restart its instances to load the changes.  You can configure the time that Docupresentment waits to check these files using the setting <entry name=”FileWatchTimeMillis”>.  By default the number is 12000ms, or 12 seconds.  You can save yourself a few CPU cycles by extending this time, or by disabling  the check altogether by setting the value to 0.  This may or may not be appropriate for your environment; if you have 100% uptime requirements then you probably don’t want to bring down an entire set of processes just to accept a new configuration value, so it’s best to leave this somewhere between 12 seconds to a few minutes.  Another point to keep in mind: if you are using Documaker real-time processing under Docupresentment the Master Resource Library (MRL) files and INI options are cached, and if you need to affect a change, you’ll have to “restart” Docupresentment.  Touching the docserv.xml file is an easy way to do this (other methods including using the RSS request, but that’s another post). The next item up: <entry name=”FilePurgeTimeSeconds”>.  You may already know that the Docupresentment system can generate many temporary files based on certain request types that are processed through the system.  What you may not know is how those files are cleaned up.  There are many rules in Docupresentment that cause the creation of temporary files.  When these files are created, Docupresentment writes an entry into a properties file called the file cache.  This file contains the name, creation date, and expiration time of each temporary file created by each instance of Docupresentment.  Periodically Docupresentment will check the file cache to determine if there are files that are past the expiration time, not unlike that block of cheese festering away in the back of my refrigerator.  However, unlike my ‘fridge cleaning tendencies, Docupresentment is quick to remove files that are past their expiration time.  You, my friend, have the power to control how often Docupresentment inspects the file cache.  Simply set the value for <entry name=”FilePurgeTimeSeconds”> to the number of seconds appropriate for your requirements and you’re set.  Note that file purging happens on a separate thread from normal request processing, so this shouldn’t interfere with response times unless the CPU happens to be really taxed at the point of cache processing.  Finally, after all of this, we get to the final setting I’m going to address in this post: <entry name=”FilePurgeList”>.  The default is “filecache.properties”.  This establishes the root name for the Docupresentment file cache that I mentioned previously.  Docupresentment creates a separate cache file for each instance based on this setting.  If you have two instances, you’ll see two files created: filecache.properties.1 and filecache.properties.2.  Feel free to open these up and check them out. I hope you’ve enjoyed this first foray into the configuration file of Docupresentment.  If you did enjoy it, feel free to drop a comment, I welcome feedback.  If you have ideas for other posts you’d like to see, please do let me know.  You can reach me at [email protected]. ‘Til next time! ###

    Read the article

  • HTML5 Form Validation

    - by Stephen.Walther
    The latest versions of Google Chrome (16+), Mozilla Firefox (8+), and Internet Explorer (10+) all support HTML5 client-side validation. It is time to take HTML5 validation seriously. The purpose of the blog post is to describe how you can take advantage of HTML5 client-side validation regardless of the type of application that you are building. You learn how to use the HTML5 validation attributes, how to perform custom validation using the JavaScript validation constraint API, and how to simulate HTML5 validation on older browsers by taking advantage of a jQuery plugin. Finally, we discuss the security issues related to using client-side validation. Using Client-Side Validation Attributes The HTML5 specification discusses several attributes which you can use with INPUT elements to perform client-side validation including the required, pattern, min, max, step, and maxlength attributes. For example, you use the required attribute to require a user to enter a value for an INPUT element. The following form demonstrates how you can make the firstName and lastName form fields required: <!DOCTYPE html> <html > <head> <title>Required Demo</title> </head> <body> <form> <label> First Name: <input required title="First Name is Required!" /> </label> <label> Last Name: <input required title="Last Name is Required!" /> </label> <button>Register</button> </form> </body> </html> If you attempt to submit this form without entering a value for firstName or lastName then you get the validation error message: Notice that the value of the title attribute is used to display the validation error message “First Name is Required!”. The title attribute does not work this way with the current version of Firefox. If you want to display a custom validation error message with Firefox then you need to include an x-moz-errormessage attribute like this: <input required title="First Name is Required!" x-moz-errormessage="First Name is Required!" /> The pattern attribute enables you to validate the value of an INPUT element against a regular expression. For example, the following form includes a social security number field which includes a pattern attribute: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Pattern</title> </head> <body> <form> <label> Social Security Number: <input required pattern="^\d{3}-\d{2}-\d{4}$" title="###-##-####" /> </label> <button>Register</button> </form> </body> </html> The regular expression in the form above requires the social security number to match the pattern ###-##-####: Notice that the input field includes both a pattern and a required validation attribute. If you don’t enter a value then the regular expression is never triggered. You need to include the required attribute to force a user to enter a value and cause the value to be validated against the regular expression. Custom Validation You can take advantage of the HTML5 constraint validation API to perform custom validation. You can perform any custom validation that you need. The only requirement is that you write a JavaScript function. For example, when booking a hotel room, you might want to validate that the Arrival Date is in the future instead of the past: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Constraint Validation API</title> </head> <body> <form> <label> Arrival Date: <input id="arrivalDate" type="date" required /> </label> <button>Submit Reservation</button> </form> <script type="text/javascript"> var arrivalDate = document.getElementById("arrivalDate"); arrivalDate.addEventListener("input", function() { var value = new Date(arrivalDate.value); if (value < new Date()) { arrivalDate.setCustomValidity("Arrival date must be after now!"); } else { arrivalDate.setCustomValidity(""); } }); </script> </body> </html> The form above contains an input field named arrivalDate. Entering a value into the arrivalDate field triggers the input event. The JavaScript code adds an event listener for the input event and checks whether the date entered is greater than the current date. If validation fails then the validation error message “Arrival date must be after now!” is assigned to the arrivalDate input field by calling the setCustomValidity() method of the validation constraint API. Otherwise, the validation error message is cleared by calling setCustomValidity() with an empty string. HTML5 Validation and Older Browsers But what about older browsers? For example, what about Apple Safari and versions of Microsoft Internet Explorer older than Internet Explorer 10? What the world really needs is a jQuery plugin which provides backwards compatibility for the HTML5 validation attributes. If a browser supports the HTML5 validation attributes then the plugin would do nothing. Otherwise, the plugin would add support for the attributes. Unfortunately, as far as I know, this plugin does not exist. I have not been able to find any plugin which supports both the required and pattern attributes for older browsers, but does not get in the way of these attributes in the case of newer browsers. There are several jQuery plugins which provide partial support for the HTML5 validation attributes including: · jQuery Validation — http://docs.jquery.com/Plugins/Validation · html5Form — http://www.matiasmancini.com.ar/jquery-plugin-ajax-form-validation-html5.html · h5Validate — http://ericleads.com/h5validate/ The jQuery Validation plugin – the most popular JavaScript validation library – supports the HTML5 required attribute, but it does not support the HTML5 pattern attribute. Likewise, the html5Form plugin does not support the pattern attribute. The h5Validate plugin provides the best support for the HTML5 validation attributes. The following page illustrates how this plugin supports both the required and pattern attributes: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>h5Validate</title> <style type="text/css"> .validationError { border: solid 2px red; } .validationValid { border: solid 2px green; } </style> </head> <body> <form id="customerForm"> <label> First Name: <input id="firstName" required /> </label> <label> Social Security Number: <input id="ssn" required pattern="^\d{3}-\d{2}-\d{4}$" title="Expected pattern is ###-##-####" /> </label> <input type="submit" /> </form> <script type="text/javascript" src="Scripts/jquery-1.4.4.min.js"></script> <script type="text/javascript" src="Scripts/jquery.h5validate.js"></script> <script type="text/javascript"> // Enable h5Validate plugin $("#customerForm").h5Validate({ errorClass: "validationError", validClass: "validationValid" }); // Prevent form submission when errors $("#customerForm").submit(function (evt) { if ($("#customerForm").h5Validate("allValid") === false) { evt.preventDefault(); } }); </script> </body> </html> When an input field fails validation, the validationError CSS class is applied to the field and the field appears with a red border. When an input field passes validation, the validationValid CSS class is applied to the field and the field appears with a green border. From the perspective of HTML5 validation, the h5Validate plugin is the best of the plugins. It adds support for the required and pattern attributes to browsers which do not natively support these attributes such as IE9. However, this plugin does not include everything in my wish list for a perfect HTML5 validation plugin. Here’s my wish list for the perfect back compat HTML5 validation plugin: 1. The plugin would disable itself when used with a browser which natively supports HTML5 validation attributes. The plugin should not be too greedy – it should not handle validation when a browser could do the work itself. 2. The plugin should simulate the same user interface for displaying validation error messages as the user interface displayed by browsers which natively support HTML5 validation. Chrome, Firefox, and Internet Explorer all display validation errors in a popup. The perfect plugin would also display a popup. 3. Finally, the plugin would add support for the setCustomValidity() method and the other methods of the HTML5 validation constraint API. That way, you could implement custom validation in a standards compatible way and you would know that it worked across all browsers both old and new. Security It would be irresponsible of me to end this blog post without mentioning the issue of security. It is important to remember that any client-side validation — including HTML5 validation — can be bypassed. You should use client-side validation with the intention to create a better user experience. Client validation is great for providing a user with immediate feedback when the user is in the process of completing a form. However, client-side validation cannot prevent an evil hacker from submitting unexpected form data to your web server. You should always enforce your validation rules on the server. The only way to ensure that a required field has a value is to verify that the required field has a value on the server. The HTML5 required attribute does not guarantee anything. Summary The goal of this blog post was to describe the support for validation contained in the HTML5 standard. You learned how to use both the required and the pattern attributes in an HTML5 form. We also discussed how you can implement custom validation by taking advantage of the setCustomValidity() method. Finally, I discussed the available jQuery plugins for adding support for the HTM5 validation attributes to older browsers. Unfortunately, I am unaware of any jQuery plugin which provides a perfect solution to the problem of backwards compatibility.

    Read the article

  • Taming Hopping Windows

    - by Roman Schindlauer
    At first glance, hopping windows seem fairly innocuous and obvious. They organize events into windows with a simple periodic definition: the windows have some duration d (e.g. a window covers 5 second time intervals), an interval or period p (e.g. a new window starts every 2 seconds) and an alignment a (e.g. one of those windows starts at 12:00 PM on March 15, 2012 UTC). var wins = xs     .HoppingWindow(TimeSpan.FromSeconds(5),                    TimeSpan.FromSeconds(2),                    new DateTime(2012, 3, 15, 12, 0, 0, DateTimeKind.Utc)); Logically, there is a window with start time a + np and end time a + np + d for every integer n. That’s a lot of windows. So why doesn’t the following query (always) blow up? var query = wins.Select(win => win.Count()); A few users have asked why StreamInsight doesn’t produce output for empty windows. Primarily it’s because there is an infinite number of empty windows! (Actually, StreamInsight uses DateTimeOffset.MaxValue to approximate “the end of time” and DateTimeOffset.MinValue to approximate “the beginning of time”, so the number of windows is lower in practice.) That was the good news. Now the bad news. Events also have duration. Consider the following simple input: var xs = this.Application                 .DefineEnumerable(() => new[]                     { EdgeEvent.CreateStart(DateTimeOffset.UtcNow, 0) })                 .ToStreamable(AdvanceTimeSettings.IncreasingStartTime); Because the event has no explicit end edge, it lasts until the end of time. So there are lots of non-empty windows if we apply a hopping window to that single event! For this reason, we need to be careful with hopping window queries in StreamInsight. Or we can switch to a custom implementation of hopping windows that doesn’t suffer from this shortcoming. The alternate window implementation produces output only when the input changes. We start by breaking up the timeline into non-overlapping intervals assigned to each window. In figure 1, six hopping windows (“Windows”) are assigned to six intervals (“Assignments”) in the timeline. Next we take input events (“Events”) and alter their lifetimes (“Altered Events”) so that they cover the intervals of the windows they intersect. In figure 1, you can see that the first event e1 intersects windows w1 and w2 so it is adjusted to cover assignments a1 and a2. Finally, we can use snapshot windows (“Snapshots”) to produce output for the hopping windows. Notice however that instead of having six windows generating output, we have only four. The first and second snapshots correspond to the first and second hopping windows. The remaining snapshots however cover two hopping windows each! While in this example we saved only two events, the savings can be more significant when the ratio of event duration to window duration is higher. Figure 1: Timeline The implementation of this strategy is straightforward. We need to set the start times of events to the start time of the interval assigned to the earliest window including the start time. Similarly, we need to modify the end times of events to the end time of the interval assigned to the latest window including the end time. The following snap-to-boundary function that rounds a timestamp value t down to the nearest value t' <= t such that t' is a + np for some integer n will be useful. For convenience, we will represent both DateTime and TimeSpan values using long ticks: static long SnapToBoundary(long t, long a, long p) {     return t - ((t - a) % p) - (t > a ? 0L : p); } How do we find the earliest window including the start time for an event? It’s the window following the last window that does not include the start time assuming that there are no gaps in the windows (i.e. duration < interval), and limitation of this solution. To find the end time of that antecedent window, we need to know the alignment of window ends: long e = a + (d % p); Using the window end alignment, we are finally ready to describe the start time selector: static long AdjustStartTime(long t, long e, long p) {     return SnapToBoundary(t, e, p) + p; } To find the latest window including the end time for an event, we look for the last window start time (non-inclusive): public static long AdjustEndTime(long t, long a, long d, long p) {     return SnapToBoundary(t - 1, a, p) + p + d; } Bringing it together, we can define the translation from events to ‘altered events’ as in Figure 1: public static IQStreamable<T> SnapToWindowIntervals<T>(IQStreamable<T> source, TimeSpan duration, TimeSpan interval, DateTime alignment) {     if (source == null) throw new ArgumentNullException("source");     // reason about DateTime and TimeSpan in ticks     long d = Math.Min(DateTime.MaxValue.Ticks, duration.Ticks);     long p = Math.Min(DateTime.MaxValue.Ticks, Math.Abs(interval.Ticks));     // set alignment to earliest possible window     var a = alignment.ToUniversalTime().Ticks % p;     // verify constraints of this solution     if (d <= 0L) { throw new ArgumentOutOfRangeException("duration"); }     if (p == 0L || p > d) { throw new ArgumentOutOfRangeException("interval"); }     // find the alignment of window ends     long e = a + (d % p);     return source.AlterEventLifetime(         evt => ToDateTime(AdjustStartTime(evt.StartTime.ToUniversalTime().Ticks, e, p)),         evt => ToDateTime(AdjustEndTime(evt.EndTime.ToUniversalTime().Ticks, a, d, p)) -             ToDateTime(AdjustStartTime(evt.StartTime.ToUniversalTime().Ticks, e, p))); } public static DateTime ToDateTime(long ticks) {     // just snap to min or max value rather than under/overflowing     return ticks < DateTime.MinValue.Ticks         ? new DateTime(DateTime.MinValue.Ticks, DateTimeKind.Utc)         : ticks > DateTime.MaxValue.Ticks         ? new DateTime(DateTime.MaxValue.Ticks, DateTimeKind.Utc)         : new DateTime(ticks, DateTimeKind.Utc); } Finally, we can describe our custom hopping window operator: public static IQWindowedStreamable<T> HoppingWindow2<T>(     IQStreamable<T> source,     TimeSpan duration,     TimeSpan interval,     DateTime alignment) {     if (source == null) { throw new ArgumentNullException("source"); }     return SnapToWindowIntervals(source, duration, interval, alignment).SnapshotWindow(); } By switching from HoppingWindow to HoppingWindow2 in the following example, the query returns quickly rather than gobbling resources and ultimately failing! public void Main() {     var start = new DateTimeOffset(new DateTime(2012, 6, 28), TimeSpan.Zero);     var duration = TimeSpan.FromSeconds(5);     var interval = TimeSpan.FromSeconds(2);     var alignment = new DateTime(2012, 3, 15, 12, 0, 0, DateTimeKind.Utc);     var events = this.Application.DefineEnumerable(() => new[]     {         EdgeEvent.CreateStart(start.AddSeconds(0), "e0"),         EdgeEvent.CreateStart(start.AddSeconds(1), "e1"),         EdgeEvent.CreateEnd(start.AddSeconds(1), start.AddSeconds(2), "e1"),         EdgeEvent.CreateStart(start.AddSeconds(3), "e2"),         EdgeEvent.CreateStart(start.AddSeconds(9), "e3"),         EdgeEvent.CreateEnd(start.AddSeconds(3), start.AddSeconds(10), "e2"),         EdgeEvent.CreateEnd(start.AddSeconds(9), start.AddSeconds(10), "e3"),     }).ToStreamable(AdvanceTimeSettings.IncreasingStartTime);     var adjustedEvents = SnapToWindowIntervals(events, duration, interval, alignment);     var query = from win in HoppingWindow2(events, duration, interval, alignment)                 select win.Count();     DisplayResults(adjustedEvents, "Adjusted Events");     DisplayResults(query, "Query"); } As you can see, instead of producing a massive number of windows for the open start edge e0, a single window is emitted from 12:00:15 AM until the end of time: Adjusted Events StartTime EndTime Payload 6/28/2012 12:00:01 AM 12/31/9999 11:59:59 PM e0 6/28/2012 12:00:03 AM 6/28/2012 12:00:07 AM e1 6/28/2012 12:00:05 AM 6/28/2012 12:00:15 AM e2 6/28/2012 12:00:11 AM 6/28/2012 12:00:15 AM e3 Query StartTime EndTime Payload 6/28/2012 12:00:01 AM 6/28/2012 12:00:03 AM 1 6/28/2012 12:00:03 AM 6/28/2012 12:00:05 AM 2 6/28/2012 12:00:05 AM 6/28/2012 12:00:07 AM 3 6/28/2012 12:00:07 AM 6/28/2012 12:00:11 AM 2 6/28/2012 12:00:11 AM 6/28/2012 12:00:15 AM 3 6/28/2012 12:00:15 AM 12/31/9999 11:59:59 PM 1 Regards, The StreamInsight Team

    Read the article

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

< Previous Page | 57 58 59 60 61 62 63 64 65 66 67 68  | Next Page >