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• Is it safe to assert a functions return type?

  - by wb

  This question is related to this question. I have several models stored in a collection. I loop through the collection and validate each field. Based on the input, a field can either be successful, have an error or a warning. Is it safe to unit test each decorator and assert that the type of object returned is what you would expect based on the given input? I could perhaps see this being an issue for a language with function return types since my validation function can return one of 3 types. This is the code I'm fiddling with: <!-- #include file = "../lib/Collection.asp" --> <style type="text/css"> td { padding: 4px; } td.error { background: #F00F00; } td.warning { background: #FC0; } </style> <% Class UserModel Private m_Name Private m_Age Private m_Height Public Property Let Name(value) m_Name = value End Property Public Property Get Name() Name = m_Name End Property Public Property Let Age(value) m_Age = value End Property Public Property Get Age() Age = m_Age End Property Public Property Let Height(value) m_Height = value End Property Public Property Get Height() Height = m_Height End Property End Class Class NameValidation Private m_Name Public Function Init(name) m_Name = name End Function Public Function Validate() Dim validationObject If Len(m_Name) < 5 Then Set validationObject = New ValidationError Else Set validationObject = New ValidationSuccess End If validationObject.CellValue = m_Name Set Validate = validationObject End Function End Class Class AgeValidation Private m_Age Public Function Init(age) m_Age = age End Function Public Function Validate() Dim validationObject If m_Age < 18 Then Set validationObject = New ValidationError ElseIf m_Age = 18 Then Set validationObject = New ValidationWarning Else Set validationObject = New ValidationSuccess End If validationObject.CellValue = m_Age Set Validate = validationObject End Function End Class Class HeightValidation Private m_Height Public Function Init(height) m_Height = height End Function Public Function Validate() Dim validationObject If m_Height > 400 Then Set validationObject = New ValidationError ElseIf m_Height = 324 Then Set validationObject = New ValidationWarning Else Set validationObject = New ValidationSuccess End If validationObject.CellValue = m_Height Set Validate = validationObject End Function End Class Class ValidationError Private m_CSSClass Private m_CellValue Public Property Get CSSClass() CSSClass = "error" End Property Public Property Let CellValue(value) m_CellValue = value End Property Public Property Get CellValue() CellValue = m_CellValue End Property End Class Class ValidationWarning Private m_CSSClass Private m_CellValue Public Property Get CSSClass() CSSClass = "warning" End Property Public Property Let CellValue(value) m_CellValue = value End Property Public Property Get CellValue() CellValue = m_CellValue End Property End Class Class ValidationSuccess Private m_CSSClass Private m_CellValue Public Property Get CSSClass() CSSClass = "" End Property Public Property Let CellValue(value) m_CellValue = value End Property Public Property Get CellValue() CellValue = m_CellValue End Property End Class Class ModelValidator Public Function ValidateModel(model) Dim modelValidation : Set modelValidation = New CollectionClass ' Validate name Dim name : Set name = New NameValidation name.Init model.Name modelValidation.Add name ' Validate age Dim age : Set age = New AgeValidation age.Init model.Age modelValidation.Add age ' Validate height Dim height : Set height = New HeightValidation height.Init model.Height modelValidation.Add height Dim validatedProperties : Set validatedProperties = New CollectionClass Dim modelVal For Each modelVal In modelValidation.Items() validatedProperties.Add modelVal.Validate() Next Set ValidateModel = validatedProperties End Function End Class Dim modelCollection : Set modelCollection = New CollectionClass Dim user1 : Set user1 = New UserModel user1.Name = "Mike" user1.Age = 12 user1.Height = 32 modelCollection.Add user1 Dim user2 : Set user2 = New UserModel user2.Name = "Phil" user2.Age = 18 user2.Height = 432 modelCollection.Add user2 Dim user3 : Set user3 = New UserModel user3.Name = "Michele" user3.Age = 32 user3.Height = 324 modelCollection.Add user3 ' Validate all models in the collection Dim modelValue Dim validatedModels : Set validatedModels = New CollectionClass For Each modelValue In modelCollection.Items() Dim objModelValidator : Set objModelValidator = New ModelValidator validatedModels.Add objModelValidator.ValidateModel(modelValue) Next %> <table> <tr> <td>Name</td> <td>Age</td> <td>Height</td> </tr> <% Dim r, c For Each r In validatedModels.Items() %><tr><% For Each c In r.Items() %><td class="<%= c.CSSClass %>"><%= c.CellValue %></td><% Next %></tr><% Next %> </table> Thank you.

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• PHP-MySQL: Arranging rows from seperate tables together/Expression to determine row origin

  - by Koroviev

  I'm new to PHP and have a two part question. I need to take rows from two separate tables, and arrange them in descending order by their date. The rows do not correspond in order or number and have no relationship with each other. ---EDIT--- They each contain updates on a site, one table holds text, links, dates, titles etc. from a blog. The other has titles, links, specifications, etc. from images. I want to arrange some basic information (title, date, small description) in an updates section on the main page of the site, and for it to be in order of date. Merging them into one table and modifying it to suit both types isn't what I'd like to do here, the blog table is Wordpress' standard wp_posts and I don't feel comfortable adding columns to make it suit the image table too. I'm afraid it could clash with upgrading later on and it seems like a clumsy solution (but that doesn't mean I'll object if people here advise me it's the best solution). ------EDIT 2------ Here are the DESCRIBES of each table: mysql> describe images; +---------+--------------+------+-----+-------------------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+--------------+------+-----+-------------------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | project | varchar(255) | NO | | NULL | | | title | varchar(255) | NO | | NULL | | | time | timestamp | NO | | CURRENT_TIMESTAMP | | | img_url | varchar(255) | NO | | NULL | | | alt_txt | varchar(255) | YES | | NULL | | | text | text | YES | | NULL | | | text_id | int(11) | YES | | NULL | | +---------+--------------+------+-----+-------------------+----------------+ mysql> DESCRIBE wp_posts; +-----------------------+---------------------+------+-----+---------------------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------------------+---------------------+------+-----+---------------------+----------------+ | ID | bigint(20) unsigned | NO | PRI | NULL | auto_increment | | post_author | bigint(20) unsigned | NO | | 0 | | | post_date | datetime | NO | | 0000-00-00 00:00:00 | | | post_date_gmt | datetime | NO | | 0000-00-00 00:00:00 | | | post_content | longtext | NO | | NULL | | | post_title | text | NO | | NULL | | | post_excerpt | text | NO | | NULL | | | post_status | varchar(20) | NO | | publish | | | comment_status | varchar(20) | NO | | open | | | ping_status | varchar(20) | NO | | open | | | post_password | varchar(20) | NO | | | | | post_name | varchar(200) | NO | MUL | | | | to_ping | text | NO | | NULL | | | pinged | text | NO | | NULL | | | post_modified | datetime | NO | | 0000-00-00 00:00:00 | | | post_modified_gmt | datetime | NO | | 0000-00-00 00:00:00 | | | post_content_filtered | text | NO | | NULL | | | post_parent | bigint(20) unsigned | NO | MUL | 0 | | | guid | varchar(255) | NO | | | | | menu_order | int(11) | NO | | 0 | | | post_type | varchar(20) | NO | MUL | post | | | post_mime_type | varchar(100) | NO | | | | | comment_count | bigint(20) | NO | | 0 | | +-----------------------+---------------------+------+-----+---------------------+----------------+ ---END EDIT--- I can do this easily with a single table like this (I include it here in case I'm using an over-elaborate method without knowing it): $content = mysql_query("SELECT post_title, post_text, post_date FROM posts ORDER BY post_date DESC"); while($row = mysql_fetch_array($content)) { echo $row['post_date'], $row['post_title'], $row['post_text']; } But how is it possible to call both tables into the same array to arrange them correctly? By correctly, I mean that they will intermix their echoed results based on their date. Maybe I'm looking at this from the wrong perspective, and calling them to a single array isn't the answer? Additionally, I need a way to form a conditional expression based on which table they came from, so that rows from table 1 get echoed differently than rows from table 2? I want results from table 1 to be echoed differently (with different strings concatenated around them, I mean) for the purpose of styling them differently than those from table two. And vice versa. I know an if...else statement would work here, but I have no idea how can I write the expression that would determine which table the row is from. All and any help is appreciated, thanks.

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• can a python script know that another instance of the same script is running... and then talk to it?

  - by Justin Grant

  I'd like to prevent multiple instances of the same long-running python command-line script from running at the same time, and I'd like the new instance to be able to send data to the original insance before the new instance commits suicide. How can I do this in a cross-platform way? Specifically, I'd like to enable the following behavior: "foo.py" is launched from the command line, and it will stay running for a long time-- days or weeks until the machine is rebooted or the parent process kills it. every few minutes the same script is launched again, but with different command-line parameters when launched, the script should see if any other instances are running. if other instances are running, then instance #2 should send its command-line parameters to instance #1, and then instance #2 should exit. instance #1, if it receives command-line parameters from another script, should spin up a new thread and (using the command-line parameters sent in the step above) start performing the work that instance #2 was going to perform. So I'm looking for two things: how can a python program know another instance of itself is running, and then how can one python command-line program communicate with another? Making this more complicated, the same script needs to run on both Windows and Linux, so ideally the solution would use only the Python standard library and not any OS-specific calls. Although if I need to have a Windows codepath and an *nix codepath (and a big if statement in my code to choose one or the other), that's OK if a "same code" solution isn't possible. I realize I could probably work out a file-based approach (e.g. instance #1 watches a directory for changes and each instance drops a file into that directory when it wants to do work) but I'm a little concerned about cleaning up those files after a non-graceful machine shutdown. I'd ideally be able to use an in-memory solution. But again I'm flexible, if a persistent-file-based approach is the only way to do it, I'm open to that option. More details: I'm trying to do this because our servers are using a monitoring tool which supports running python scripts to collect monitoring data (e.g. results of a database query or web service call) which the monitoring tool then indexes for later use. Some of these scripts are very expensive to start up but cheap to run after startup (e.g. making a DB connection vs. running a query). So we've chosen to keep them running in an infinite loop until the parent process kills them. This works great, but on larger servers 100 instances of the same script may be running, even if they're only gathering data every 20 minutes each. This wreaks havoc with RAM, DB connection limits, etc. We want to switch from 100 processes with 1 thread to one process with 100 threads, each executing the work that, previously, one script was doing. But changing how the scripts are invoked by the monitoring tool is not possible. We need to keep invocation the same (launch a process with different command-line parameters) but but change the scripts to recognize that another one is active, and have the "new" script send its work instructions (from the command line params) over to the "old" script.

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• Is it possible to reference a linkbotton outside an update panel as the update trigger?

  - by Selase

  I have a page based on a master page and as such i can only see the content place holders i used in the master page showing up in the aspx pages based on the master page. the source code shown below: <%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="CaseAdmin.aspx.cs" Inherits="Prototype4.CaseAdmin" %> <%@PreviousPageType VirtualPath="~/Account/Login.aspx"%> <asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" runat="server"> </asp:Content> <asp:Content ID="CaseRightNews" ContentPlaceHolderID="RightNewsItem" runat="server"> </asp:Content> <asp:Content ID="CaseLeftNav" ContentPlaceHolderID="LeftNavigation" runat="server"> <div style="margin-top:20px; margin-bottom:20px;"> <p class="actionButton"> <asp:LinkButton ID="OpenCaseLinkButton" runat="server" onclick="OpenCaseLinkButton_Click">Open Case</asp:LinkButton> </p> <p class="actionButton"><asp:LinkButton ID="RegisterExhibitLinkButton" runat="server" onclick="RegisterExhibitLinkButton_Click">Register Exhibit</asp:LinkButton> </p> </div> </asp:Content> <asp:Content ID="CaseMainContnt" ContentPlaceHolderID="MainContent" runat="server"> <asp:ScriptManager ID="ScriptManager" runat="server" /> <asp:UpdatePanel ID="CaseMainCntntUpdatePanel" UpdateMode="Conditional" runat="server"> <Triggers> <asp:AsyncPostBackTrigger ControlID="" eventname="Click"/> </Triggers> <ContentTemplate> <%--Some text here to inform user to click on the open case botton to display open case form--%> </ContentTemplate> </asp:UpdatePanel> <asp:UpdatePanel runat="server" id="UpdatePanel1" updatemode="Conditional"> <Triggers> <asp:AsyncPostBackTrigger ControlID="" eventname="Click"/> </Triggers> <ContentTemplate> <%--some text here to inform users to click on the add exhibit botton to display add exhibit form--%> </ContentTemplate> </asp:UpdatePanel> </asp:Content> the section of the entire page i wish to change upon update is the (this is the main content of the page). for this reason i placed the updatepanel inside the content place holder since it cant be sitting outside and not wrapped in a content place holder. However, the buttons that i wish to apply the trigger that fires the update to, are in another content place holder(). How can i possibly get those buttons to act as the trigger while changing only what appears in the main content area. Plus, i tried getting the updatepanel to work just so i could see if it does the update well but it turned out really bad. i added some linkbottons in the content template area and used them as the triggers for testing reasons. i tested and the changes took over the entire page in contrast to just appearing in the content area. I actually just wanted to load a form that is created in another asp. page into the main content area... I seriously need help with this... Every little help, detail and information is dearly appreciated... thanks so much in advance

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• Rails ActiveRecord friendly code from a Complex Join, Sum, and Group query

  - by Chad M

  PROBLEM Hello, I am having no luck trying to break down this SQL statement into ActiveRecord/Rails friendly code and I'd like to learn how I can avoid a find_by_sql statement in this situation. Scenario I have users that create audits when they perform an action. Each audit is of a specific audit_activity. Each audit_activity is worth a certain number of points, based on score_weight. I need to find the total scores of each user, based on their total accumulated audit_activity score_weights. Eventually I'll need to rank them which means adding a sort to this as well. My Code Here is my sql and simplified versions of the tables in question. Any thoughts? SQL with full column names (for clarity) SELECT users.id, u.email, SUM(audit_activity.score_weight) FROM users JOIN audits ON users.id = audits.user_id JOIN audit_activities ON audit_activities.id = audits.audit_activity_id GROUP BY users.id; Models: User, Audit, AuditActivity User fields: id, email class User < ActiveRecord::Base include Clearance::User has_many :audits end Audit fields: id, user_id, audit_activity_id class Audit < ActiveRecord::Base belongs_to :user belongs_to :audit_activity end AuditActivity fields: id, score_weight class AuditActivity < ActiveRecord::Base has_many :audits end Example Data Here is a set of SQL statements so you can play with similar data I'm working with and see what comes up when the concerned query is run. You should just be able to copy/paste the whole thing into a database query browser. CREATE TABLE users( id INTEGER NOT NULL, email TEXT (25), PRIMARY KEY (id) ); CREATE TABLE audits( id INTEGER NOT NULL, user_id INTEGER, audit_activity_id INTEGER, PRIMARY KEY (id) ); CREATE TABLE audit_activities( id INTEGER NOT NULL, score_weight INTEGER, PRIMARY KEY (id) ); INSERT INTO users(id, email) VALUES(1, "[email protected]"); INSERT INTO users(id, email) VALUES(2, "[email protected]"); INSERT INTO users(id, email) VALUES(3, "[email protected]"); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(1, 1, 1); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(2, 1, 2); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(3, 1, 1); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(4, 1, 3); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(5, 1, 1); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(6, 1, 4); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(7, 2, 4); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(8, 2, 4); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(9, 2, 4); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(10, 3, 3); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(11, 3, 2); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(12, 3, 2); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(13, 3, 2); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(14, 3, 3); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(15, 3, 1); INSERT INTO audits(id, user_id, audit_activity_id) VALUES(16, 3, 1); INSERT INTO audit_activities(id, score_weight) VALUES(1, 1); INSERT INTO audit_activities(id, score_weight) VALUES(2, 2); INSERT INTO audit_activities(id, score_weight) VALUES(3, 7); INSERT INTO audit_activities(id, score_weight) VALUES(4, 11); The Query Again, here is the query. SELECT u.id, u.email, SUM(aa.score_weight) FROM users u JOIN audits a ON u.id = a.user_id JOIN audit_activities aa ON aa.id = a.audit_activity_id GROUP BY u.id; Many Thanks, Chad

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• Please help fix and optimize this query

  - by user607217

  I am working on a system to find potential duplicates in our customers table (SQL 2005). I am using the built-in SOUNDEX value that our software computes when customers are added/updated, but I also implemented the double metaphone algorithm for better matching. This is the most-nested query I have created, and I can't help but think there is a better way to do it and I'd like to learn. In the inner-most query I am joining the customer table to the metaphone table I created, then finding customers that have identical pKey (primary phonetic key). I take that, union that with customers that have matching soundex values, and then proceed to score those matches with various text similarity functions. This is currently working, but I would also like to add a union of customers whose aKey (alternate phonetic key) match. This would be identical to "QUERY A" except to substitute on (c1Akey = c2Akey) for the join. However, when I attempt to include that, I get errors when I try to execute my query. Here is the code: --Create aggregate ranking select c1Name, c2Name, nDiff, c1Addr, c2Addr, aDiff, c1SSN, c2SSN, sDiff, c1DOB, c2DOB, dDiff, nDiff+aDiff+dDiff+sDiff as Score ,(sDiff+dDiff)*1.5 + (nDiff+dDiff)*1.5 + (nDiff+sDiff)*1.5 + aDiff *.5 + nDiff *.5 as [Rank] FROM ( --Create match scores for different fields SELECT c1Name, c2Name, c1Addr, c2Addr, c1SSN, c2SSN, c1LTD, c2LTD, c1DOB, c2DOB, dbo.Jaro(c1name, c2name) AS nDiff, dbo.JaroWinkler(c1addr, c2addr) AS aDiff, CASE WHEN c1dob = '1901-01-01' OR c2dob = '1901-01-01' OR c1dob = '1800-01-01' OR c2dob = '1800-01-01' THEN .5 ELSE dbo.SmithWaterman(c1dob, c2dob) END AS dDiff, CASE WHEN c1ssn = '000-00-0000' OR c2ssn = '000-00-0000' THEN .5 ELSE dbo.Jaro(c1ssn, c2ssn) END AS sDiff FROM -- Generate list of possible matches based on multiple phonetic matching fields ( select * from -- List of similar names from pKey field of ##Metaphone table --QUERY A BEGIN (select customers.custno as c1Custno, name as c1Name, haddr as c1Addr, ssn as c1SSN, lasttripdate as c1LTD, dob as c1DOB, soundex as c1Soundex, pkey as c1Pkey, akey as c1Akey from Customers WITH (nolock) join ##Metaphone on customers.custno = ##Metaphone.custno) as c1 JOIN (select customers.custno as c2Custno, name as c2Name, haddr as c2Addr, ssn as c2SSN, lasttripdate as c2LTD, dob as c2DOB, soundex as c2Soundex, pkey as c2Pkey, akey as c2Akey from Customers with (nolock) join ##Metaphone on customers.custno = ##Metaphone.custno) as c2 on (c1Pkey = c2Pkey) and (c1Custno < c2Custno) WHERE (c1Name <> 'PARENT, GUARDIAN') and c1soundex != c2soundex --QUERY A END union --List of similar names from pregenerated SOUNDEX field (select t1.custno, t1.name, t1.haddr, t1.ssn, t1.lasttripdate, t1.dob, t1.[soundex], 0, 0, t2.custno, t2.name, t2.haddr, t2.ssn, t2.lasttripdate, t2.dob, t2.[soundex], 0, 0 from Customers t1 WITH (nolock) join customers t2 with (nolock) on t1.[soundex] = t2.[soundex] and t1.custno < t2.custno where (t1.name <> 'PARENT, GUARDIAN')) ) as a ) as b where (sDiff+dDiff)*1.5 + (nDiff+dDiff)*1.5 + (nDiff+sDiff)*1.5 + aDiff *.5 + nDiff *.5 >= 7.5 order by [rank] desc, score desc Previously, I was using joins such as on c1.pkey = c2.pkey or c1.akey = c2.akey or c1.soundex = c2.soundex but the performance was horrendous, and using unions seems to be working a lot better. Out of 103K customers, tt is currently generating a list of 8.5M potential matches (based on the phonetic codes) in 2.25 minutes, and then taking another 2 to score, rank and filter those down to about 3000. So I am happy with the performance, I just can't help but think there is a better way to structure this, and I need help adding the extra union condition. Thanks!

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• Fastest way to pad a number in Java to a certain number of digits

  - by Martin

  Am trying to create a well-optimised bit of code to create number of X-digits in length (where X is read from a runtime properties file), based on a DB-generated sequence number (Y), which is then used a folder-name when saving a file. I've come up with three ideas so far, the fastest of which is the last one, but I'd appreciate any advice people may have on this... 1) Instantiate a StringBuilder with initial capacity X. Append Y. While length < X, insert a zero at pos zero. 2) Instantiate a StringBuilder with initial capacity X. While length < X, append a zero. Create a DecimalFormat based on StringBuilder value, and then format the number when it's needed. 3) Create a new int of Math.pow( 10, X ) and add Y. Use String.valueOf() on the new number and then substring(1) it. The second one can obviously be split into outside-loop and inside-loop sections. So, any tips? Using a for-loop of 10,000 iterations, I'm getting similar timings from the first two, and the third method is approximately ten-times faster. Does this seem correct? Full test-method code below... // Setup test variables int numDigits = 9; int testNumber = 724; int numIterations = 10000; String folderHolder = null; DecimalFormat outputFormat = new DecimalFormat( "#,##0" ); // StringBuilder test long before = System.nanoTime(); for ( int i = 0; i < numIterations; i++ ) { StringBuilder sb = new StringBuilder( numDigits ); sb.append( testNumber ); while ( sb.length() < numDigits ) { sb.insert( 0, 0 ); } folderHolder = sb.toString(); } long after = System.nanoTime(); System.out.println( "01: " + outputFormat.format( after - before ) + " nanoseconds" ); System.out.println( "Sanity check: Folder = \"" + folderHolder + "\"" ); // DecimalFormat test before = System.nanoTime(); StringBuilder sb = new StringBuilder( numDigits ); while ( sb.length() < numDigits ) { sb.append( 0 ); } DecimalFormat formatter = new DecimalFormat( sb.toString() ); for ( int i = 0; i < numIterations; i++ ) { folderHolder = formatter.format( testNumber ); } after = System.nanoTime(); System.out.println( "02: " + outputFormat.format( after - before ) + " nanoseconds" ); System.out.println( "Sanity check: Folder = \"" + folderHolder + "\"" ); // Substring test before = System.nanoTime(); int baseNum = (int)Math.pow( 10, numDigits ); for ( int i = 0; i < numIterations; i++ ) { int newNum = baseNum + testNumber; folderHolder = String.valueOf( newNum ).substring( 1 ); } after = System.nanoTime(); System.out.println( "03: " + outputFormat.format( after - before ) + " nanoseconds" ); System.out.println( "Sanity check: Folder = \"" + folderHolder + "\"" );

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• String Sharing/Reference issue with objects in Delphi

  - by jenakai123

  My application builds many objects in memory based on filenames (among other string based information). I was hoping to optimise memory usage by storing the path and filename separately, and then sharing the path between objects in the same path. I wasn't trying to look at using a string pool or anything, basically my objects are sorted so if I have 10 objects with the same path I want objects 2-10 to have their path "pointed" at object 1's path (eg object[2].Path=object[1].Path); I have a problem though, I don't believe that my objects are in fact sharing a reference to the same string after I think I am telling them to (by the object[2].Path=object[1].Path assignment). When I do an experiment with a string list and set all the values to point to the first value in the list I can see the "memory conservation" in action, but when I use objects I see absolutely no change at all, admittedly I am only using task manager (private working set) to watch for memory use changes. Here's a contrived example, I hope this makes sense. I have an object: TfileObject=class(Tobject) FpathPart: string; FfilePart: string; end; Now I create 1,000,000 instances of the object, using a new string for each one: var x: integer; MyFilePath: string; fo: TfileObject; begin for x := 1 to 1000000 do begin // create a new string for every iteration of the loop MyFilePath:=ExtractFilePath(Application.ExeName); fo:=TfileObject.Create; fo.FpathPart:=MyFilePath; FobjectList.Add(fo); end; end; Run this up and task manager says I am using 68MB of memory or something. (Note that if I allocated MyFilePath outside of the loop then I do save memory because of 1 instance of the string, but this is a contrived example and not actually how it would happen in the app). Now I want to "optimise" my memory usage by making all objects share the same instance of the path string, since it's the same value: var x: integer; begin for x:=1 to FobjectList.Count-1 do begin TfileObject(FobjectList[x]).FpathPart:=TfileObject(FobjectList[0]).FpathPart; end; end; Task Manager shows absouletly no change. However if I do something similar with a TstringList: var x: integer; begin for x := 1 to 1000000 do begin FstringList.Add(ExtractFilePath(Application.ExeName)); end; end; Task Manager says 60MB memory use. Now optimise with: var x: integer; begin for x := 1 to FstringList.Count - 1 do FstringList[x]:=FstringList[0]; end; Task Manager shows the drop in memory usage that I would expect, now 10MB. So I seem to be able to share strings in a string list, but not in objects. I am obviously missing something conceptually, in code or both! I hope this makes sense, I can really see the ability to conserve memory using this technique as I have a lot of objects all with lots of string information, that data is sorted in many different ways and I would like to be able to iterate over this data once it is loaded into memory and free some of that memory back up again by sharing strings in this way. Thanks in advance for any assistance you can offer.

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• Dot Net Nuke module works in "Edit" mode but not for "View": cache problem?

  - by Godeke

  I have a DNN task that simply runs some Javascript to compute a price based on a few input fields. This module works fine on our production site, but we had a company do a skin for us to improve the look of the site and the module fails under this new system. (DNN 05.06.00 (459) although it was 5.5 prior... I updated in a futile hope that it was a bug in the old revision.) What is incredibly odd about this is that the module works fine when I'm logged in to DNN and using the Edit mode as an administrator. In this case the small snippet of JavaScript loads fine and filling the fields results in a price. On the other hand it I click "View" (or more importantly, if I'm not logged in at all) the page loads a cached copy. Even odder, I have found the cache files in \Portals\2\Cache\Pages are generated and then only the cached data is being used. When the cached copy is loaded, the JavaScript doesn't appear (it is normally created via a Page.ClientScript.RegisterClientScriptBlock(). Additionally, the button which posts the data to the server doesn't execute any of the server side code (confirmed with a debugger) but instead just reloads the cached copy. If I manually delete the files in \Portals\2\Cache\Pages then everything works properly, but I have to do so after every page load: failing to do so simply loads the page as it was last generated repeatedly. Resetting the application (either via the UI or editing web.config) doesn't change this and clearing the cache from the Host Settings page doesn't actually clear these cached pages. I'm guessing that Edit mode bypasses the cache in some way, but I have gone as far as turning off all caching on the site (which is horrible for performance) and the cached version is still loaded. Has anyone seen anything like this? Shouldn't clearing the cache clear the files (I'm using the File provider for caching)? Shouldn't even a cached page go back to the server if the user posts back? EDIT: I should point out that permissions don't appear to be a problem on the cache directory... other pages cached output are deleted from this folder, just this page has this issue. EDIT 2: Clarifying some settings and conditions which I didn't provide. First, this module works fine in production under DNN 5.6.0. In our test environment with the consulting company's changes it fails (the changes are skin and page layout only in theory: the module source itself verifies as unchanged). All cache settings and the like have been verified the same between the two and we only resorted to setting the module cache to 0 and -1 (and disabling the test site's cache entirely) when we couldn't find another cause for the problem. I have watched the cache work correctly on many other pages in test: there is something about this page that is causing the problem. We have punted and are creating an installable skin based on the consultant's work as I suspect they have somehow corrupted the DNN install (database side I think).

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• Grabbing all <a> tags in a specific div and displaying them

  - by Taylor Swyter

  So I'v got a small problem with my portfolio site (you can see it at here) When you click on a portfolio piece, a top section opens up to reveal the details (Title, year, role, description) as well as the photos. I'v been able to get each project to replace all the text data, but I can't seem to get the images to load into the thumbnails. I have been able to get the last image i'm looking for in all of the images on the site, but not display each photo for each project. Here's the HTML i'm working with: <section id="details"> <div class="pagewrapper"> <section id="main-img"> <article id="big-img"> <img src="" alt="big-img" /> </article> <article class="small-img-container"> <a href="#"><img src="#" alt="smallimg" class="small-img" /></a> </article> </section> <section id="description"> <h3></h3> <h4></h4> <h5></h5> <p></p> </section> </div> <div class="clear"></div> </section> <section id="portfolio"> <div class="pagewrapper"> <h2 class="sectionTitle">Portfolio</h2> <div class="thumb"> <a class="small" href="#" title="David Lockwood Music" data-year="2010" data-role="Sole Wordpress Developer" data-description="David Lockwood is a musician and an educator based in New Hampshire who came to me needing a website for his musical career. I fully developed his site using Wordpress as a CMS, creating a custom template based on the design by Jeremiah Louf. Jeremiah and I worked together on the website's UX design."><img src="images_original/davidcover.png" alt="thumb" /> <div class="hide"> <a href="images/davidlockwood/homepage.png" ></a> <a href="images/davidlockwood/blog.png"></a> <a href="images/davidlockwood/shows.png"></a> <a href="images/davidlockwood/bio.png"></a> <a href="images/davidlockwood/photos.png"></a> </div> <h3>David Lockwood Music</h3> <div class="clear"></div> </a> </div><!--thumb--> and here's the jQuery: $(document).ready(function(){ var proj = {}; $('.thumb a').click(function() { $('#details').slideDown(1000); $('.hide a').each(function() { proj.img = $(this).attr("href"); $('.small-img-container img').attr('src',proj.img); }); alert("the image is " + proj.img);//is it getting the image URLS? proj.title = $(this).attr("title"); proj.year = $(this).attr("data-year"); proj.role = $(this).attr("data-role"); proj.description = $(this).attr("data-description"); $('#description h3').text(proj.title); $('#description h4').text(proj.year); $('#description h5').text(proj.role); $('#description p').text(proj.description); }); }); Anyone have any idea how I grab just the images for the specific project, display them all as thumbnails and then make those thumbnail clickable to see the bigger image? Thanks!

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• Trying to packetize TCP with non-blocking IO is hard! Am I doing something wrong?

  - by Ricket

  Oh how I wish TCP was packet-based like UDP is! But alas, that's not the case, so I'm trying to implement my own packet layer. Here's the chain of events so far (ignoring writing packets) Oh, and my Packets are very simply structured: two unsigned bytes for length, and then byte[length] data. (I can't imagine if they were any more complex, I'd be up to my ears in if statements!) Server is in an infinite loop, accepting connections and adding them to a list of Connections. PacketGatherer (another thread) uses a Selector to figure out which Connection.SocketChannels are ready for reading. It loops over the results and tells each Connection to read(). Each Connection has a partial IncomingPacket and a list of Packets which have been fully read and are waiting to be processed. On read(): Tell the partial IncomingPacket to read more data. (IncomingPacket.readData below) If it's done reading (IncomingPacket.complete()), make a Packet from it and stick the Packet into the list waiting to be processed and then replace it with a new IncomingPacket. There are a couple problems with this. First, only one packet is being read at a time. If the IncomingPacket needs only one more byte, then only one byte is read this pass. This can of course be fixed with a loop but it starts to get sorta complicated and I wonder if there is a better overall way. Second, the logic in IncomingPacket is a little bit crazy, to be able to read the two bytes for the length and then read the actual data. Here is the code, boiled down for quick & easy reading: int readBytes; // number of total bytes read so far byte length1, length2; // each byte in an unsigned short int (see getLength()) public int getLength() { // will be inaccurate if readBytes < 2 return (int)(length1 << 8 | length2); } public void readData(SocketChannel c) { if (readBytes < 2) { // we don't yet know the length of the actual data ByteBuffer lengthBuffer = ByteBuffer.allocate(2 - readBytes); numBytesRead = c.read(lengthBuffer); if(readBytes == 0) { if(numBytesRead >= 1) length1 = lengthBuffer.get(); if(numBytesRead == 2) length2 = lengthBuffer.get(); } else if(readBytes == 1) { if(numBytesRead == 1) length2 = lengthBuffer.get(); } readBytes += numBytesRead; } if(readBytes >= 2) { // then we know we have the entire length variable // lazily-instantiate data buffers based on getLength() // read into data buffers, increment readBytes // (does not read more than the amount of this packet, so it does not // need to handle overflow into the next packet's data) } } public boolean complete() { return (readBytes > 2 && readBytes == getLength()+2); } Basically I need feedback on my code. Please suggest any improvements. Even overhauling my entire system would be okay, if you have suggestions for how better to implement the whole thing. Book recommendations are welcome too; I love books. I just get the feeling that something isn't quite right.

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• Create a named cell dynamically

  - by CaptMorgan

  I have a workbook with 3 worksheets. 1 worksheet will have input values (not created at the moment and not needed for this question), 1 worksheet with several "template" or "source" tables, and the last worksheet has 4 formatted "target" tables (empty or not doesn't matter). Each template table has 3 columns, 1 column identifying what the values are for in the second 2 columns. The value columns have formulas in them and each cell is Named. The formulas use the cell Names rather than cell address (e.g. MyData1 instead of C2). I am trying to copy the templates into the target tables while also either copying the cell Names from the source into the targets or create the Names in the target tables based on the source cell Names. My code below I am creating the target names by using a "base" in the Name that will be changed depending on which target table it gets copied to. my sample tables have "Num0_" for a base in all the cell names (e.g. Num0_MyData1, Num0_SomeOtherData2, etc). Once the copy has completed the code will then name the cells by looking at the target Names (and address), replacing the base of the name with a new base, just adding a number of which target table it goes to, and replacing the sheet name in the address. Here's where I need help. The way I am changing that address will only work if my template and target are using the same cell addresses of their perspective sheets. Which they are not. (e.g. Template1 table has value cells, each named, of B2 thru C10, and my target table for the copy may be F52 thur G60). Bottom line I need to figure out how to copy those names over with the templates or name the cells dynamically by doing something like a replace where I am incrementing the address value based on my target table #...remember I have 4 target tables which are static, I will only copy to those areas. I am a newbie to vba so any suggestions or help is appreciated. NOTE: The copying of the table works as I want. It even names the cells (if the Template and Target Table have the same local worksheet cell address (e.g. C2) 'Declare Module level variables 'Variables for target tables are defined in sub's for each target table. Dim cellName As Name Dim newName As String Dim newAddress As String Dim newSheetVar Dim oldSheetVar Dim oldNameVar Dim srcTable1 Sub copyTables() newSheetVar = "TestSheet" oldSheetVar = "Templates" oldNameVar = "Num0_" srcTable1 = "TestTableTemplate" 'Call sub functions to copy tables, name cells and update functions. copySrc1Table copySrc2Table End Sub '****there is another sub identical to this one below for copySrc2Table. Sub copySrc1Table() newNameVar = "Num1_" trgTable1 = "SourceEnvTable1" Sheets(oldSheetVar).Select Range(srcTable1).Select Selection.Copy For Each cellName In ActiveWorkbook.Names 'Find all names with common value If cellName.Name Like oldNameVar & "*" Then 'Replace the common value with the update value you need newName = Replace(cellName.Name, oldNameVar, newNameVar) newAddress = Replace(cellName.RefersTo, oldSheetVar, newSheetVar) 'Edit the name of the name. This will change any formulas using this name as well ActiveWorkbook.Names.Add Name:=newName, RefersTo:=newAddress End If Next cellName Sheets(newSheetVar).Select Range(trgTable1).Select Selection.PasteSpecial Paste:=xlPasteAll, Operation:=xlNone, SkipBlanks:= _ False, Transpose:=False End Sub PING

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• Reordering Variadic Parameters

  - by void-pointer

  I have come across the need to reorder a variadic list of parameters that is supplied to the constructor of a struct. After being reordered based on their types, the parameters will be stored as a tuple. My question is how this can be done so that a modern C++ compiler (e.g. g++-4.7) will not generate unnecessary load or store instructions. That is, when the constructor is invoked with a list of parameters of variable size, it efficiently pushes each parameter into place based on an ordering over the parameters' types. Here is a concrete example. Assume that the base type of every parameter (without references, rvalue references, pointers, or qualifiers) is either char, int, or float. How can I make it so that all the parameters of base type char appear first, followed by all of those of base type int (which leaves the parameters of base type float last). The relative order in which the parameters were given should not be violated within sublists of homogeneous base type. Example: foo::foo() is called with arguments float a, char&& b, const float& c, int&& d, char e. The tuple tupe is std::tuple<char, char, int, float, float>, and it is constructed like so: tuple_type{std::move(b), e, std::move(d), a, c}. Consider the struct defined below, and assume that the metafunction deduce_reordered_tuple_type is already implemented. How would you write the constructor so that it works as intended? If you think that the code for deduce_reodered_tuple_type, would be useful to you, I can provide it; it's a little long. template <class... Args> struct foo { // Assume that the metafunction deduce_reordered_tuple_type is defined. typedef typename deduce_reordered_tuple_type<Args...>::type tuple_type; tuple_type t_; foo(Args&&... args) : t_{reorder_and_forward_parameters<Args>(args)...} {} }; Edit 1 The technique I describe above does have applications in mathematical frameworks that make heavy use of expression templates, variadic templates, and metaprogramming in order to perform aggressive inlining. Suppose that you wish to define an operator that takes the product of several expressions, each of which may be passed by reference, reference to const, or rvalue reference. (In my case, the expressions are conditional probability tables and the operation is the factor product, but something like matrix multiplication works suitably as well.) You need access to the data provided by each expression in order to evaluate the product. Consequently, you must move the expressions passed as rvalue references, copy the expressions passed by reference to const, and take the addresses of expressions passed by reference. Using the technique I describe above now poses several benefits. Other expressions can use uniform syntax to access data elements from this expression, since all of the heavy-lifting metaprogramming work is done beforehand, within the class. We can save stack space by grouping the pointers together and storing the larger expressions towards the end of the tuple. Implementing certain types of queries becomes much easier (e.g. check whether any of the pointers stored in the tuple aliases a given pointer). Thank you very much for your help!

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• Return NSArray from NSDictionary

  - by Jon

  I have a fetch that returns an array with dictionary in it of an attribute of a core data object. Here is my previous question: Create Array From Attribute of NSObject From NSFetchResultsController This is the fetch: NSFetchRequest *request = [[NSFetchRequest alloc] init]; [request setEntity:entity]; [request setResultType:NSDictionaryResultType]; [request setReturnsDistinctResults:NO]; //set to YES if you only want unique values of the property [request setPropertiesToFetch :[NSArray arrayWithObject:@"timeStamp"]]; //name(s) of properties you want to fetch // Execute the fetch. NSError *error; NSArray *objects = [managedObjectContext executeFetchRequest:request error:&error]; When I log the NSArray data, I get this: The content of data is( { timeStamp = "2011-06-14 21:30:03 +0000"; }, { timeStamp = "2011-06-16 21:00:18 +0000"; }, { timeStamp = "2011-06-11 21:00:18 +0000"; }, { timeStamp = "2011-06-23 19:53:35 +0000"; }, { timeStamp = "2011-06-21 19:53:35 +0000"; } ) What I want is an array with this format: [NSArray arrayWithObjects: @"2011-11-01 00:00:00 +0000", @"2011-12-01 00:00:00 +0000", nil];' Edit: This is the method for which I want to replace the data array with my new data array: - (NSArray*)calendarMonthView:(TKCalendarMonthView *)monthView marksFromDate:(NSDate *)startDate toDate:(NSDate *)lastDate { NSLog(@"calendarMonthView marksFromDate toDate"); NSLog(@"Make sure to update 'data' variable to pull from CoreData, website, User Defaults, or some other source."); // When testing initially you will have to update the dates in this array so they are visible at the // time frame you are testing the code. NSArray *data = [NSArray arrayWithObjects: @"2011-01-01 00:00:00 +0000", @"2011-12-01 00:00:00 +0000", nil]; // Initialise empty marks array, this will be populated with TRUE/FALSE in order for each day a marker should be placed on. NSMutableArray *marks = [NSMutableArray array]; // Initialise calendar to current type and set the timezone to never have daylight saving NSCalendar *cal = [NSCalendar currentCalendar]; [cal setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]]; // Construct DateComponents based on startDate so the iterating date can be created. // Its massively important to do this assigning via the NSCalendar and NSDateComponents because of daylight saving has been removed // with the timezone that was set above. If you just used "startDate" directly (ie, NSDate *date = startDate;) as the first // iterating date then times would go up and down based on daylight savings. NSDateComponents *comp = [cal components:(NSMonthCalendarUnit | NSMinuteCalendarUnit | NSYearCalendarUnit | NSDayCalendarUnit | NSWeekdayCalendarUnit | NSHourCalendarUnit | NSSecondCalendarUnit) fromDate:startDate]; NSDate *d = [cal dateFromComponents:comp]; // Init offset components to increment days in the loop by one each time NSDateComponents *offsetComponents = [[NSDateComponents alloc] init]; [offsetComponents setDay:1]; // for each date between start date and end date check if they exist in the data array while (YES) { // Is the date beyond the last date? If so, exit the loop. // NSOrderedDescending = the left value is greater than the right if ([d compare:lastDate] == NSOrderedDescending) { break; } // If the date is in the data array, add it to the marks array, else don't if ([data containsObject:[d description]]) { [marks addObject:[NSNumber numberWithBool:YES]]; } else { [marks addObject:[NSNumber numberWithBool:NO]]; } // Increment day using offset components (ie, 1 day in this instance) d = [cal dateByAddingComponents:offsetComponents toDate:d options:0]; } [offsetComponents release]; return [NSArray arrayWithArray:marks]; }

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• Extending JavaScript's Date.parse to allow for DD/MM/YYYY (non-US formatted dates)?

  - by Campbeln

  I've come up with this solution to extending JavaScript's Date.parse function to allow for dates formatted in DD/MM/YYYY (rather then the American standard [and default] MM/DD/YYYY): (function() { var fDateParse = Date.parse; Date.parse = function(sDateString) { var a_sLanguage = ['en','en-us'], a_sMatches = null, sCurrentLanguage, dReturn = null, i ; //#### Traverse the a_sLanguages (as reported by the browser) for (i = 0; i < a_sLanguage.length; i++) { //#### Collect the .toLowerCase'd sCurrentLanguage for this loop sCurrentLanguage = (a_sLanguage[i] + '').toLowerCase(); //#### If this is the first English definition if (sCurrentLanguage.indexOf('en') == 0) { //#### If this is a definition for a non-American based English (meaning dates are "DD MM YYYY") if (sCurrentLanguage.indexOf('en-us') == -1 && // en-us = English (United States) + Palau, Micronesia, Philippians sCurrentLanguage.indexOf('en-ca') == -1 && // en-ca = English (Canada) sCurrentLanguage.indexOf('en-bz') == -1 // en-bz = English (Belize) ) { //#### Setup a oRegEx to locate "## ## ####" (allowing for any sort of delimiter except a '\n') then collect the a_sMatches from the passed sDateString var oRegEx = new RegExp("(([0-9]{2}|[0-9]{1})[^0-9]*?([0-9]{2}|[0-9]{1})[^0-9]*?([0-9]{4}))", "i"); a_sMatches = oRegEx.exec(sDateString); } //#### Fall from the loop (as we've found the first English definition) break; } } //#### If we were able to find a_sMatches for a non-American English "DD MM YYYY" formatted date if (a_sMatches != null) { var oRegEx = new RegExp(a_sMatches[0], "i"); //#### .parse the sDateString via the normal Date.parse function, but replacing the "DD?MM?YYYY" with "YYYY/MM/DD" beforehand //#### NOTE: a_sMatches[0]=[Default]; a_sMatches[1]=DD?MM?YYYY; a_sMatches[2]=DD; a_sMatches[3]=MM; a_sMatches[4]=YYYY dReturn = fDateParse(sDateString.replace(oRegEx, a_sMatches[4] + "/" + a_sMatches[3] + "/" + a_sMatches[2])); } //#### Else .parse the sDateString via the normal Date.parse function else { dReturn = fDateParse(sDateString); } //#### return dReturn; } })(); In my actual (dotNet) code, I'm collecting the a_sLanguage array via: a_sLanguage = '<% Response.Write(Request.ServerVariables["HTTP_ACCEPT_LANGUAGE"]); %>'.split(','); Now, I'm not certain my approach to locating "us-en"/etc. is the most proper. Pretty much it's just the US and current/former US influenced areas (Palau, Micronesia, Philippines) + Belize & Canada that use the funky MM/DD/YYYY format (I am American, so I can call it funky =). So one could rightly argue that if the Locale is not "en-us"/etc. first, then DD/MM/YYYY should be used. Thoughts? As a side note... I "grew up" in PERL but it's been a wee while since I've done much heavy lifting in RegEx. Does that expression look right to everyone? This seems like a lot of work, but based on my research this is indeed about the best way to go about enabling DD/MM/YYYY dates within JavaScript. Is there an easier/more betterer way? PS- Upon re-reading this post just before submission... I've realized that this is more of a "can you code review this" rather then a question (or, an answer is embedded within the question). When I started writing this it was not my intention to end up here =)

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• Generating strongly biased radom numbers for tests

  - by nobody

  I want to run tests with randomized inputs and need to generate 'sensible' random numbers, that is, numbers that match good enough to pass the tested function's preconditions, but hopefully wreak havoc deeper inside its code. math.random() (I'm using Lua) produces uniformly distributed random numbers. Scaling these up will give far more big numbers than small numbers, and there will be very few integers. I would like to skew the random numbers (or generate new ones using the old function as a randomness source) in a way that strongly favors 'simple' numbers, but will still cover the whole range, I.e. extending up to positive/negative infinity (or ±1e309 for double). This means: numbers up to, say, ten should be most common, integers should be more common than fractions, numbers ending in 0.5 should be the most common fractions, followed by 0.25 and 0.75; then 0.125, and so on. A different description: Fix a base probability x such that probabilities will sum to one and define the probability of a number n as xk where k is the generation in which n is constructed as a surreal number1. That assigns x to 0, x2 to -1 and +1, x3 to -2, -1/2, +1/2 and +2, and so on. This gives a nice description of something close to what I want (it skews a bit too much), but is near-unusable for computing random numbers. The resulting distribution is nowhere continuous (it's fractal!), I'm not sure how to determine the base probability x (I think for infinite precision it would be zero), and computing numbers based on this by iteration is awfully slow (spending near-infinite time to construct large numbers). Does anyone know of a simple approximation that, given a uniformly distributed randomness source, produces random numbers very roughly distributed as described above? I would like to run thousands of randomized tests, quantity/speed is more important than quality. Still, better numbers mean less inputs get rejected. Lua has a JIT, so performance can't be reasonably predicted. Jumps based on randomness will break every prediction, and many calls to math.random() will be slow, too. This means a closed formula will be better than an iterative or recursive one. 1 Wikipedia has an article on surreal numbers, with a nice picture. A surreal number is a pair of two surreal numbers, i.e. x := {n|m}, and its value is the number in the middle of the pair, i.e. (for finite numbers) {n|m} = (n+m)/2 (as rational). If one side of the pair is empty, that's interpreted as increment (or decrement, if right is empty) by one. If both sides are empty, that's zero. Initially, there are no numbers, so the only number one can build is 0 := { | }. In generation two one can build numbers {0| } =: 1 and { |0} =: -1, in three we get {1| } =: 2, {|1} =: -2, {0|1} =: 1/2 and {-1|0} =: -1/2 (plus some more complex representations of known numbers, e.g. {-1|1} ? 0). Note that e.g. 1/3 is never generated by finite numbers because it is an infinite fraction – the same goes for floats, 1/3 is never represented exactly.

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• create previous next button for iframe pages

  - by Resu

  This topic may have lots of code out there, BUT I seem to be looking for a variation that isn't based on history, is it possible... So I have this code... <script type="text/javascript"> var pages=new Array(); pages[0]="listItem1.html"; pages[1]="listItem2.html"; pages[2]="listItem3.html"; pages[3]="listItem4.html"; pages[4]="listItem5.html"; var i=0; var end=pages.length; end--; function changeSrc(operation) { if (operation=="next") { if (i==end) { document.getElementById('the_iframe').src=pages[end]; i=0;} else { document.getElementById('the_iframe').src=pages[i]; i++;}} if (operation=="back") { if (i==0) { document.getElementById('the_iframe').src=pages[0]; i=end;} else { document.getElementById('the_iframe').src=pages[i]; i--;}}} </script> </head> <body> <ul id="menu" role="group"> <li><a href="listItem1.html" target="ifrm" role="treeitem">Welcome</a> <ul> <li><a href="listItem2.html" target="ifrm" role="treeitem">Ease of Access Center</a></li> </ul> </li> <li><a href="listItem3.html" target="ifrm">Getting Started</a> <ul> <li><a href="listItem4.html" target="ifrm">Considerations</a></li> <li><a href="listItem5.html" target="ifrm">Changing Perspective</a></li> </ul> </li> </ul> <iframe id="the_iframe" scrolling="no" src="listItem1.htm" name="ifrm" style="width:540px;></iframe> <input type="button" onClick="changeSrc('back');" value="Back" /> <input type="button" onClick="changeSrc('next');" value="Next" /> and if I click on the next or prev button, it does move somewhere,but... let's say my iframe is showing listItem2, then I click on listItem4 in the menu (there is a tree menu involved), then I want to go to listItem3 and I hit the back button...instead of going to listItem3, it goes to listItem2 (or someplace that is not back a page from 4 to 3). It appears that the buttons are navigating based on history?...but I just want a straight forward or backward movement...I don't want my buttons to have this browser-type functionality...If I'm on listItem4 and hit the next button, I want it to go to listItem5. Many Thanks For Any Help!

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• How to prevent DIVs from sliding over each other

  - by Haghpanah

  I’m going to use DIV-based layout instead of table-based to reduce amount of markups and speed up page loading, however I’ve found it too much tricky as I’m not CSS guru. I use following CSS class to simulate rows of a table containing one column for label and one for textbox. .FormItem { margin-left: auto; margin-right: auto; width: 604px; min-height: 36px; } .ItemLabel { float: left; width: 120px; padding: 3px 1px 1px 1px; text-align: right; } .ItemTextBox { float: right; width: 480px; padding: 1px 1px 1px 1px; text-align: left; } , <div class="FormItem"> <div class="ItemLabel"> <asp:Label ID="lblName" runat="server" Text="Name :"></asp:Label> </div> <div class="ItemTextBox"> <asp:TextBox ID="txtName" runat="server"></asp:TextBox> <p><span>User Name</span></p> </div> </div> <div class="FormItem"> <div class="ItemLabel"> <asp:Label ID="lblComments" runat="server" Text="Comments :"></asp:Label> </div> <div class="ItemTextBox"> <asp:TextBox ID="txtComments" runat="server"></asp:TextBox> <p><span>(optional)Comments</span></p> </div> </div> These styles work fine if the height of ItemData DIVs are less than or equal to FormItem DIVs min-height. If ItemData DIVs height gets more than FormItem height then ItemText DIVs start sliding over FormItem DIVs to and ItemText and ItemData are no longer aligned. For example the following markups… <div class="FormItem"> <div class="ItemLabel"> <asp:Label ID="lblName" runat="server" Text="Name :"></asp:Label> </div> <div class="ItemTextBox"> <asp:TextBox ID="txtName" runat="server"></asp:TextBox> <p><span>User Name</span></p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> </div> </div> <div class="FormLabel"> <div class="ItemText"> <asp:Label ID="lblComments" runat="server" Text="Comments :"></asp:Label> </div> <div class="ItemTextBox"> <asp:TextBox ID="txtComments" runat="server"></asp:TextBox> <p><span>(optional)Comments</span></p> </div> </div> I've tried several CSS attributes such as; position, float, clear… but I can not correct the problem. I’ll be appreciated for any help.

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• I am making a maze type of game using javascript and HTML and need some questions answered [on hold]

  - by Timothy Bilodeau

  First off, i am a noob to JavaScript but am willing to learn. :) I found a simple JavaScript moment engine created by another member on this site. Using that i made it so my character can walk around within a rectangle/square shaped room. I want to make it so the character can walk through a "doorway" within a wall to the next room. Either that or make it so if the character moves over a certain image within the room it will take the player to another webpage in which the character "spawns" into the room and so on and so fourth. Here is a link to what i have made so far as to get an idea. http://bit.ly/1fSMesA Any help would be much appreciated. Here is the javascript code for the character movement and boundaries. <script type='text/javascript'> // movement vars var xpos = 100; var ypos = 100; var xspeed = 1; var yspeed = 0; var maxSpeed = 5; // boundary var minx = 37; var miny = 41; var maxx = 187; // 10 pixels for character's width var maxy = 178; // 10 pixels for character's width // controller vars var upPressed = 0; var downPressed = 0; var leftPressed = 0; var rightPressed = 0; function slowDownX() { if (xspeed > 0) xspeed = xspeed - 1; if (xspeed < 0) xspeed = xspeed + 1; } function slowDownY() { if (yspeed > 0) yspeed = yspeed - 1; if (yspeed < 0) yspeed = yspeed + 1; } function gameLoop() { // change position based on speed xpos = Math.min(Math.max(xpos + xspeed,minx),maxx); ypos = Math.min(Math.max(ypos + yspeed,miny),maxy); // or, without boundaries: // xpos = xpos + xspeed; // ypos = ypos + yspeed; // change actual position document.getElementById('character').style.left = xpos; document.getElementById('character').style.top = ypos; // change speed based on keyboard events if (upPressed == 1) yspeed = Math.max(yspeed - 1,-1*maxSpeed); if (downPressed == 1) yspeed = Math.min(yspeed + 1,1*maxSpeed) if (rightPressed == 1) xspeed = Math.min(xspeed + 1,1*maxSpeed); if (leftPressed == 1) xspeed = Math.max(xspeed - 1,-1*maxSpeed); // deceleration if (upPressed == 0 && downPressed == 0) slowDownY(); if (leftPressed == 0 && rightPressed == 0) slowDownX(); // loop setTimeout("gameLoop()",10); } function keyDown(e) { var code = e.keyCode ? e.keyCode : e.which; if (code == 38) upPressed = 1; if (code == 40) downPressed = 1; if (code == 37) leftPressed = 1; if (code == 39) rightPressed = 1; } function keyUp(e) { var code = e.keyCode ? e.keyCode : e.which; if (code == 38) upPressed = 0; if (code == 40) downPressed = 0; if (code == 37) leftPressed = 0; if (code == 39) rightPressed = 0; } </script> here is the HTML code to follow <!-- The Level --> <img src="room1.png" /> <!-- The Character --> <img id='character' src='../texture packs/characters/snazgel.png' style='position:absolute;left:100;top:100;height:40;width:26;'/>

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• Blank Mail from PHP application

  - by brettlwilliams

  Problem: Blank email from PHP web application. Confirmed: App works in Linux, has various problems in Windows server environment. Blank emails are the last remaining problem. PHP Version 5.2.6 on the server I'm a librarian implementing a PHP based web application to help students complete their assignments.I have installed this application before on a Linux based free web host and had no problems. Email is controlled by two files, email_functions.php and email.php. While email can be sent, all that is sent is a blank email. My IT department is an ASP only shop, so I can get little to no help there. I also cannot install additional libraries like PHPmail or Swiftmailer. You can see a functional copy at http://rpc.elm4you.org/ You can also download a copy from Sourceforge from the link there. Thanks in advance for any insight into this! email_functions.php <?php /********************************************************** Function: build_multipart_headers Author: Michael Berkowski Last Modified: September 2007 *********************************************************** Purpose: Creates email headers for a message of type multipart/mime This will include a plain text part and HTML. **********************************************************/ function build_multipart_headers($boundary_rand) { global $EMAIL_FROM_DISPLAY_NAME, $EMAIL_FROM_ADDRESS, $CALC_PATH, $CALC_TITLE, $SERVER_NAME; // Using \n instead of \r\n because qmail doubles up the \r and screws everything up! $crlf = "\n"; $message_date = date("r"); // Construct headers for multipart/mixed MIME email. It will have a plain text and HTML part $headers = "X-Calc-Name: $CALC_TITLE" . $crlf; $headers .= "X-Calc-Url: http://{$SERVER_NAME}/{$CALC_PATH}" . $crlf; $headers .= "MIME-Version: 1.0" . $crlf; $headers .= "Content-type: multipart/alternative;" . $crlf; $headers .= " boundary=__$boundary_rand" . $crlf; $headers .= "From: $EMAIL_FROM_DISPLAY_NAME <$EMAIL_FROM_ADDRESS>" . $crlf; $headers .= "Sender: $EMAIL_FROM_DISPLAY_NAME <$EMAIL_FROM_ADDRESS>" . $crlf; $headers .= "Reply-to: $EMAIL_FROM_DISPLAY_NAME <$EMAIL_FROM_ADDRESS>" . $crlf; $headers .= "Return-Path: $EMAIL_FROM_DISPLAY_NAME <$EMAIL_FROM_ADDRESS>" . $crlf; $headers .= "Date: $message_date" . $crlf; $headers .= "Message-Id: $boundary_rand@$SERVER_NAME" . $crlf; return $headers; } /********************************************************** Function: build_multipart_body Author: Michael Berkowski Last Modified: September 2007 *********************************************************** Purpose: Builds the email body content to go with the headers from build_multipart_headers() **********************************************************/ function build_multipart_body($plain_text_message, $html_message, $boundary_rand) { //$crlf = "\r\n"; $crlf = "\n"; $boundary = "__" . $boundary_rand; // Begin constructing the MIME multipart message $multipart_message = "This is a multipart message in MIME format." . $crlf . $crlf; $multipart_message .= "--{$boundary}{$crlf}Content-type: text/plain; charset=\"us-ascii\"{$crlf}Content-Transfer-Encoding: 7bit{$crlf}{$crlf}"; $multipart_message .= $plain_text_message . $crlf . $crlf; $multipart_message .= "--{$boundary}{$crlf}Content-type: text/html; charset=\"iso-8859-1\"{$crlf}Content-Transfer-Encoding: 7bit{$crlf}{$crlf}"; $multipart_message .= $html_message . $crlf . $crlf; $multipart_message .= "--{$boundary}--$crlf$crlf"; return $multipart_message; } /********************************************************** Function: build_step_email_body_text Author: Michael Berkowski Last Modified: September 2007 *********************************************************** Purpose: Returns a plain text version of the email body to be used for individually sent step reminders **********************************************************/ function build_step_email_body_text($stepnum, $arr_instructions, $dates, $query_string, $teacher_info ,$name, $class, $project_id) { global $CALC_PATH, $CALC_TITLE, $SERVER_NAME; $step_email_body =<<<BODY $CALC_TITLE Step $stepnum: {$arr_instructions["step$stepnum"]["title"]} Name: $name Class: $class BODY; $step_email_body .= build_text_single_step($stepnum, $arr_instructions, $dates, $query_string, $teacher_info); $step_email_body .= "\n\n"; $step_email_body .=<<<FOOTER The $CALC_TITLE offers suggestions, but be sure to check with your teacher to find out the best working schedule for your assignment! If you would like to stop receiving further reminders for this project, click the link below: http://$SERVER_NAME/$CALC_PATH/deleteproject.php?proj=$project_id FOOTER; // Wrap text to 78 chars per line // Convert any remaining HTML <br /> to \r\n // Strip out any remaining HTML tags. $step_email_body = strip_tags(linebreaks_html2text(wordwrap($step_email_body, 78, "\n"))); return $step_email_body; } /********************************************************** Function: build_step_email_body_html Author: Michael Berkowski Last Modified: September 2007 *********************************************************** Purpose: Same as above, but with HTML **********************************************************/ function build_step_email_body_html($stepnum, $arr_instructions, $dates, $query_string, $teacher_info, $name, $class, $project_id) { global $CALC_PATH, $CALC_TITLE, $SERVER_NAME; $styles = build_html_styles(); $step_email_body =<<<BODY <html> <head> <title> $CALC_TITLE </title> $styles </head> <body> <h1> $CALC_TITLE Schedule </h1> <strong>Name:</strong> $name <br /> <strong>Class:</strong> $class <br /> BODY; $step_email_body .= build_html_single_step($stepnum, $arr_instructions, $dates, $query_string, $teacher_info); $step_email_body .=<<<FOOTER <p> The $CALC_TITLE offers suggestions, but be sure to check with your teacher to find out the best working schedule for your assignment! </p> <p> If you would like to stop receiving further reminders for this project, <a href="http://{$SERVER_NAME}/$CALC_PATH/deleteproject.php?proj=$project_id">click this link.</a> </p> </body> </html> FOOTER; return $step_email_body; } /********************************************************** Function: build_html_styles Author: Michael Berkowski Last Modified: September 2007 *********************************************************** Purpose: Just returns a string of <style /> for the HTML message body **********************************************************/ function build_html_styles() { $styles =<<<STYLES <style type="text/css"> body { font-family: Arial, sans-serif; font-size: 85%; } h1 { font-size: 120%; } table { border: none; } tr { vertical-align: top; } img { display: none; } hr { border: 0; } </style> STYLES; return $styles; } /********************************************************** Function: linebreaks_html2text Author: Michael Berkowski Last Modified: October 2007 *********************************************************** Purpose: Convert <br /> html tags to \n line breaks **********************************************************/ function linebreaks_html2text($in_string) { $out_string = ""; $arr_br = array("<br>", "<br />", "<br/>"); $out_string = str_replace($arr_br, "\n", $in_string); return $out_string; } ?> email.php <?php require_once("include/config.php"); require_once("include/instructions.php"); require_once("dbase/dbfunctions.php"); require_once("include/email_functions.php"); ini_set("sendmail_from", "[email protected]"); ini_set("SMTP", "mail.qatar.net.qa"); // Verify that the email has not already been sent by checking for a cookie // whose value is generated each time the form is loaded freshly. if (!(isset($_COOKIE['rpc_transid']) && $_COOKIE['rpc_transid'] == $_POST['transid'])) { // Setup some preliminary variables for email. // The scanning of $_POST['email']already took place when this file was included... $to = $_POST['email']; $subject = $EMAIL_SUBJECT; $boundary_rand = md5(rand()); $mail_type = ""; switch ($_POST['reminder-type']) { case "progressive": $arr_dbase_dates = array(); $conn = rpc_connect(); if (!$conn) { $mail_success = FALSE; $mail_status_message = "Could not register address!"; break; } // Sanitize all the data that will be inserted into table... // We need to remove "CONTENT-TYPE:" from name/class to defang them. // Additionall, we can't allow any line-breaks in those fields to avoid // hacks to email headers. $ins_name = mysql_real_escape_string($name); $ins_name = eregi_replace("CONTENT-TYPE", "...Content_Type...", $ins_name); $ins_name = str_replace("\n", "", $ins_name); $ins_class = mysql_real_escape_string($class); $ins_class = eregi_replace("CONTENT-TYPE", "...Content_Type...", $ins_class); $ins_class = str_replace("\n", "", $ins_class); $ins_email = mysql_real_escape_string($email); $ins_teacher_info = $teacher_info ? "YES" : "NO"; switch ($format) { case "Slides": $ins_format = "SLIDES"; break; case "Video": $ins_format = "VIDEO"; break; case "Essay": default: $ins_format = "ESSAY"; break; } // The transid from the previous form will be used as a project identifier // Steps will be grouped by project identifier. $ins_project_id = mysql_real_escape_string($_POST['transid'] . md5(rand())); $arr_dbase_dates = dbase_dates($dates); $arr_past_dates = array(); // Iterate over the dates array and build a SQL statement for each one. $insert_success = TRUE; // $min_reminder_date = date("Ymd", mktime(0,0,0,date("m"),date("d")+$EMAIL_REMINDER_DAYS_AHEAD,date("Y"))); for ($date_index = 0; $date_index < sizeof($arr_dbase_dates); $date_index++) { // Make sure we're using the right keys... $ins_date_index = $date_index + 1; // The insert will only happen if the date of the event is in the future. // For dates today and earlier, no insert. // For dates today or after the reminder deadline, we'll send the email immediately after the inserts. if ($arr_dbase_dates[$date_index] > (int)$min_reminder_date) { $qry =<<<QRY INSERT INTO email_queue ( NOTIFICATION_ID, PROJECT_ID, EMAIL, NAME, CLASS, FORMAT, TEACHER_INFO, STEP, MESSAGE_DATE ) VALUES ( NULL, '$ins_project_id', '$ins_email', '$ins_name', '$ins_class', '$ins_format', '$ins_teacher_info', $ins_date_index, /*step number*/ {$arr_dbase_dates[$date_index]} /* Date in the integer format yyyymmdd */ ) QRY; // Attempt to do the insert... $result = mysql_query($qry); // If even one insert fails, bail out. if (!$result) { $mail_success = FALSE; $mail_status_message = "Could not register address!"; break; } } // For dates today or earlier, store the steps=>dates in an array so the mails can // be sent immediately. else { $arr_past_dates[$ins_date_index] = $arr_dbase_dates[$date_index]; } } // Close the connection resources. mysql_close($conn); // SEND OUT THE EMAILS THAT HAVE TO GO IMMEDIATELY... // This should only be step 1, but who knows... //var_dump($arr_past_dates); for ($stepnum=1; $stepnum<=sizeof($arr_past_dates); $stepnum++) { $email_teacher_info = ($teacher_info && $EMAIL_TEACHER_REMINDERS) ? TRUE : FALSE; $boundary = md5(rand()); $plain_text_body = build_step_email_body_text($stepnum, $arr_instructions, $dates, $query_string, $email_teacher_info ,$name, $class, $ins_project_id); $html_body = build_step_email_body_html($stepnum, $arr_instructions, $dates, $query_string, $email_teacher_info ,$name, $class, $ins_project_id); $multipart_headers = build_multipart_headers($boundary); $multipart_body = build_multipart_body($plain_text_body, $html_body, $boundary); mail($to, $subject . ": Step " . $stepnum, $multipart_body, $multipart_headers, "[email protected]"); } // Set appropriate flags and messages $mail_success = TRUE; $mail_status_message = "Email address registered!"; $mail_type = "progressive"; set_mail_success_cookie(); break; // Default to a single email message. case "single": default: // We don't want to send images in the message, so strip them out of the existing structure. // This big ugly regex strips the whole table cell containing the image out of the table. // Must find a better solution... //$email_table_html = eregi_replace("<td class=\"stepImageContainer\" width=\"161px\">[\s\r\n\t]*<img class=\"stepImage\" src=\"images/[_a-zA-Z0-9]*\.gif\" alt=\"Step [1-9]{1} logo\" />[\s\r\n\t]*</td>", "\n", $table_html); // Show more descriptive text based on the value of $format switch ($format) { case "Video": $format_display = "Video"; break; case "Slides": $format_display = "Presentation with electronic slides"; break; case "Essay": default: $format_display = "Essay"; break; } $days = (int)$days; $html_message = ""; $styles = build_html_styles(); $html_message =<<<HTMLMESSAGE <html> <head> <title> $CALC_TITLE </title> $styles </head> <body> <h1> $CALC_TITLE Schedule </h1> <strong>Name:</strong> $name <br /> <strong>Class:</strong> $class <br /> <strong>Email:</strong> $email <br /> <strong>Assignment type:</strong> $format_display <br /><br /> <strong>Starting on:</strong> $date1 <br /> <strong>Assignment due:</strong> $date2 <br /> <strong>You have $days days to finish.</strong><br /> <hr /> $email_table_html </body> </html> HTMLMESSAGE; // Create the plain text version of the message... $plain_text_message = strip_tags(linebreaks_html2text(build_text_all_steps($arr_instructions, $dates, $query_string, $teacher_info))); // Add the title, since it doesn't get built in by build_text_all_steps... $plain_text_message = $CALC_TITLE . " Schedule\n\n" . $plain_text_message; $plain_text_message = wordwrap($plain_text_message, 78, "\n"); $multipart_headers = build_multipart_headers($boundary_rand); $multipart_message = build_multipart_body($plain_text_message, $html_message, $boundary_rand); $mail_success = FALSE; if (mail($to, $subject, $multipart_message, $multipart_headers, "[email protected]")) { $mail_success = TRUE; $mail_status_message = "Email sent!"; $mail_type = "single"; set_mail_success_cookie(); } else { $mail_success = FALSE; $mail_status_message = "Could not send email!"; } break; } } function set_mail_success_cookie() { // Prevent the mail from being resent on page reload. Set a timestamp cookie. // Expires in 24 hours. setcookie("rpc_transid", $_POST['transid'], time() + 86400); } ?>

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• Should one replace the usage addJSONData of jqGrid to the usage of setGridParam(), and trigger('relo

  - by Oleg

  Hi everybody who use jqGrid! I am a new on stackoverflow.com and it seems to me that a lot of peoples who use stackoverflow.com are not only the persons who have a problem which must be quickly solved. A lot of people read stackoverflow.com to look at well-known things from the other side. Sometime perhaps the reason is a self-training (to stay in the good form) during solving of problems other people. For all these gays, who not want only to solve his problem is my question. I wrote recently an answer to the question "jqGrid display default “loading” message when updating a table / on custom update". During writing of the answer I thought: why he uses addJSONData() function for refresh of data in the grid instead of changing URL with respect of setGridParam() and refreshing jqGrid data with respect of trigger('reloadGrid')? At the beginning I wanted to recommend using of 'reloadGrid', but after thinking about this I understood, that I am not quite sure what the best way is. At least I can't explain in two sentences why I prefer the second way. So I decide that it could be an interesting subject of a discussion. So to be exactly: We have a typical situation. We have a web page with at least one jqGrid and some other controls like combo-boxes (selects), checkboxes etc. which give user possibilities to change scope on information displayed in a jqGrid. Typically we define some event handler like jQuery("#selector").change(myRefresh).keyup(myKeyRefresh) and we need reload the jqGrid contain based on users choose. After reading and analyzing of the information from additional users input we can refresh jqGrid contain in at least two ways: Make call of $.ajax() manual and then inside of success or complete handle of $.ajax call jQuery.parseJSON() (or eval) and then call addJSONData function of jqGrid. I found a lot of examples on stackoverflow.com who use addJSONData. Update url of jqGrid based on users input, reset current page number to 1 and optionally change the caption of the grid. All these can be done with respect of setGridParam(), and optionally setCaption() jqGrid methods. At the end one call trigger('reloadGrid') method of the grid. To construct the url, by the way I use mostly jQuery.param function to be sure, that I all url parameters packed correctly with respect of encodeURIComponent. I want that we discuss advantages and disadvantages of both ways. I use currently the second way, so I start with advantages of this one. One can say me: I call existing Web Service, convert received data to the jqGrid format and call addJSONData. This is the reason why I use addJSONData method! OK, I choose another way. jqGrid can make a call of the Web Service directly and fill results inside of grid. There are a lot of jqGrid options, which allow you to customize this process. First of all, one can delete or rename any standard parameter sent to server with respect of prmNames option of jqGrid or add any more additional parameters with respect of postData option (see http://www.trirand.com/jqgridwiki/doku.php?id=wiki:options). One can modify all constructed parameters immediately before jqGrid makes corresponding $.ajax request by defining of serializeGridData() function (one more option of jqGrid). More than that, one can change every $.ajax parameter by setting ajaxGridOptions option of jqGrid. I use ajaxGridOptions: {contentType: "application/json"} for example as a general setting of $.jgrid.defaults. The ajaxGridOptions option is very powerful. With respect of ajaxGridOptions option one can redefine any parameter of $.ajax request sending by jqGrid, like error, complete and beforeSend events. I see potentially interesting to define dataFilter event to be able makes any modification of the row data responded from the server. One more argument for using of trigger('reloadGrid') way is blocking of jqGrid during ajax request processing. Mostly I use parameter loadui: 'block' to block jqGrid during JSON request sending to server. With respect of jQuery blockUI plugin http://malsup.com/jquery/block/ one can block more parts of web page as the grid only. To do this one can call jQuery('#main').block({ message: '<h1>Die Daten werden vom Server geladen...</h1>' }); before calling of trigger('reloadGrid') method and jQuery('#main').unblock() inside of loadComplete and loadError functions. The loadui option could be set to 'disable' in this case. So I don’t see why the function addJSONData() should be used. Can somebody who use addJSONData() function explain me advantages of its usage? Should one replace the usage addJSONData of jqGrid to the usage of setGridParam(), and trigger('reloadGrid')? I am opened to the discussion.

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• .NET HTML Sanitation for rich HTML Input

  - by Rick Strahl

  Recently I was working on updating a legacy application to MVC 4 that included free form text input. When I set up the new site my initial approach was to not allow any rich HTML input, only simple text formatting that would respect a few simple HTML commands for bold, lists etc. and automatically handles line break processing for new lines and paragraphs. This is typical for what I do with most multi-line text input in my apps and it works very well with very little development effort involved. Then the client sprung another note: Oh by the way we have a bunch of customers (real estate agents) who need to post complete HTML documents. Oh uh! There goes the simple theory. After some discussion and pleading on my part (<snicker>) to try and avoid this type of raw HTML input because of potential XSS issues, the client decided to go ahead and allow raw HTML input anyway. There has been lots of discussions on this subject on StackOverFlow (and here and here) but to after reading through some of the solutions I didn't really find anything that would work even closely for what I needed. Specifically we need to be able to allow just about any HTML markup, with the exception of script code. Remote CSS and Images need to be loaded, links need to work and so. While the 'legit' HTML posted by these agents is basic in nature it does span most of the full gamut of HTML (4). Most of the solutions XSS prevention/sanitizer solutions I found were way to aggressive and rendered the posted output unusable mostly because they tend to strip any externally loaded content. In short I needed a custom solution. I thought the best solution to this would be to use an HTML parser - in this case the Html Agility Pack - and then to run through all the HTML markup provided and remove any of the blacklisted tags and a number of attributes that are prone to JavaScript injection. There's much discussion on whether to use blacklists vs. whitelists in the discussions mentioned above, but I found that whitelists can make sense in simple scenarios where you might allow manual HTML input, but when you need to allow a larger array of HTML functionality a blacklist is probably easier to manage as the vast majority of elements and attributes could be allowed. Also white listing gets a bit more complex with HTML5 and the new proliferation of new HTML tags and most new tags generally don't affect XSS issues directly. Pure whitelisting based on elements and attributes also doesn't capture many edge cases (see some of the XSS cheat sheets listed below) so even with a white list, custom logic is still required to handle many of those edge cases. The Microsoft Web Protection Library (AntiXSS) My first thought was to check out the Microsoft AntiXSS library. Microsoft has an HTML Encoding and Sanitation library in the Microsoft Web Protection Library (formerly AntiXSS Library) on CodePlex, which provides stricter functions for whitelist encoding and sanitation. Initially I thought the Sanitation class and its static members would do the trick for me,but I found that this library is way too restrictive for my needs. Specifically the Sanitation class strips out images and links which rendered the full HTML from our real estate clients completely useless. I didn't spend much time with it, but apparently I'm not alone if feeling this library is not really useful without some way to configure operation. To give you an example of what didn't work for me with the library here's a small and simple HTML fragment that includes script, img and anchor tags. I would expect the script to be stripped and everything else to be left intact. Here's the original HTML:var value = "<b>Here</b> <script>alert('hello')</script> we go. Visit the " + "<a href='http://west-wind.com'>West Wind</a> site. " + "<img src='http://west-wind.com/images/new.gif' /> " ; and the code to sanitize it with the AntiXSS Sanitize class:@Html.Raw(Microsoft.Security.Application.Sanitizer.GetSafeHtmlFragment(value)) This produced a not so useful sanitized string: Here we go. Visit the <a>West Wind</a> site. While it removed the <script> tag (good) it also removed the href from the link and the image tag altogether (bad). In some situations this might be useful, but for most tasks I doubt this is the desired behavior. While links can contain javascript: references and images can 'broadcast' information to a server, without configuration to tell the library what to restrict this becomes useless to me. I couldn't find any way to customize the white list, nor is there code available in this 'open source' library on CodePlex. Using Html Agility Pack for HTML Parsing The WPL library wasn't going to cut it. After doing a bit of research I decided the best approach for a custom solution would be to use an HTML parser and inspect the HTML fragment/document I'm trying to import. I've used the HTML Agility Pack before for a number of apps where I needed an HTML parser without requiring an instance of a full browser like the Internet Explorer Application object which is inadequate in Web apps. In case you haven't checked out the Html Agility Pack before, it's a powerful HTML parser library that you can use from your .NET code. It provides a simple, parsable HTML DOM model to full HTML documents or HTML fragments that let you walk through each of the elements in your document. If you've used the HTML or XML DOM in a browser before you'll feel right at home with the Agility Pack. Blacklist based HTML Parsing to strip XSS Code For my purposes of HTML sanitation, the process involved is to walk the HTML document one element at a time and then check each element and attribute against a blacklist. There's quite a bit of argument of what's better: A whitelist of allowed items or a blacklist of denied items. While whitelists tend to be more secure, they also require a lot more configuration. In the case of HTML5 a whitelist could be very extensive. For what I need, I only want to ensure that no JavaScript is executed, so a blacklist includes the obvious <script> tag plus any tag that allows loading of external content including <iframe>, <object>, <embed> and <link> etc. <form>  is also excluded to avoid posting content to a different location. I also disallow <head> and <meta> tags in particular for my case, since I'm only allowing posting of HTML fragments. There is also some internal logic to exclude some attributes or attributes that include references to JavaScript or CSS expressions. The default tag blacklist reflects my use case, but is customizable and can be added to. Here's my HtmlSanitizer implementation:using System.Collections.Generic; using System.IO; using System.Xml; using HtmlAgilityPack; namespace Westwind.Web.Utilities { public class HtmlSanitizer { public HashSet<string> BlackList = new HashSet<string>() { { "script" }, { "iframe" }, { "form" }, { "object" }, { "embed" }, { "link" }, { "head" }, { "meta" } }; /// <summary> /// Cleans up an HTML string and removes HTML tags in blacklist /// </summary> /// <param name="html"></param> /// <returns></returns> public static string SanitizeHtml(string html, params string[] blackList) { var sanitizer = new HtmlSanitizer(); if (blackList != null && blackList.Length > 0) { sanitizer.BlackList.Clear(); foreach (string item in blackList) sanitizer.BlackList.Add(item); } return sanitizer.Sanitize(html); } /// <summary> /// Cleans up an HTML string by removing elements /// on the blacklist and all elements that start /// with onXXX . /// </summary> /// <param name="html"></param> /// <returns></returns> public string Sanitize(string html) { var doc = new HtmlDocument(); doc.LoadHtml(html); SanitizeHtmlNode(doc.DocumentNode); //return doc.DocumentNode.WriteTo(); string output = null; // Use an XmlTextWriter to create self-closing tags using (StringWriter sw = new StringWriter()) { XmlWriter writer = new XmlTextWriter(sw); doc.DocumentNode.WriteTo(writer); output = sw.ToString(); // strip off XML doc header if (!string.IsNullOrEmpty(output)) { int at = output.IndexOf("?>"); output = output.Substring(at + 2); } writer.Close(); } doc = null; return output; } private void SanitizeHtmlNode(HtmlNode node) { if (node.NodeType == HtmlNodeType.Element) { // check for blacklist items and remove if (BlackList.Contains(node.Name)) { node.Remove(); return; } // remove CSS Expressions and embedded script links if (node.Name == "style") { if (string.IsNullOrEmpty(node.InnerText)) { if (node.InnerHtml.Contains("expression") || node.InnerHtml.Contains("javascript:")) node.ParentNode.RemoveChild(node); } } // remove script attributes if (node.HasAttributes) { for (int i = node.Attributes.Count - 1; i >= 0; i--) { HtmlAttribute currentAttribute = node.Attributes[i]; var attr = currentAttribute.Name.ToLower(); var val = currentAttribute.Value.ToLower(); span style="background: white; color: green">// remove event handlers if (attr.StartsWith("on")) node.Attributes.Remove(currentAttribute); // remove script links else if ( //(attr == "href" || attr== "src" || attr == "dynsrc" || attr == "lowsrc") && val != null && val.Contains("javascript:")) node.Attributes.Remove(currentAttribute); // Remove CSS Expressions else if (attr == "style" && val != null && val.Contains("expression") || val.Contains("javascript:") || val.Contains("vbscript:")) node.Attributes.Remove(currentAttribute); } } } // Look through child nodes recursively if (node.HasChildNodes) { for (int i = node.ChildNodes.Count - 1; i >= 0; i--) { SanitizeHtmlNode(node.ChildNodes[i]); } } } } } Please note: Use this as a starting point only for your own parsing and review the code for your specific use case! If your needs are less lenient than mine were you can you can make this much stricter by not allowing src and href attributes or CSS links if your HTML doesn't allow it. You can also check links for external URLs and disallow those - lots of options.  The code is simple enough to make it easy to extend to fit your use cases more specifically. It's also quite easy to make this code work using a WhiteList approach if you want to go that route. The code above is semi-generic for allowing full featured HTML fragments that only disallow script related content. The Sanitize method walks through each node of the document and then recursively drills into all of its children until the entire document has been traversed. Note that the code here uses an XmlTextWriter to write output - this is done to preserve XHTML style self-closing tags which are otherwise left as non-self-closing tags. The sanitizer code scans for blacklist elements and removes those elements not allowed. Note that the blacklist is configurable either in the instance class as a property or in the static method via the string parameter list. Additionally the code goes through each element's attributes and looks for a host of rules gleaned from some of the XSS cheat sheets listed at the end of the post. Clearly there are a lot more XSS vulnerabilities, but a lot of them apply to ancient browsers (IE6 and versions of Netscape) - many of these glaring holes (like CSS expressions - WTF IE?) have been removed in modern browsers. What a Pain To be honest this is NOT a piece of code that I wanted to write. I think building anything related to XSS is better left to people who have far more knowledge of the topic than I do. Unfortunately, I was unable to find a tool that worked even closely for me, or even provided a working base. For the project I was working on I had no choice and I'm sharing the code here merely as a base line to start with and potentially expand on for specific needs. It's sad that Microsoft Web Protection Library is currently such a train wreck - this is really something that should come from Microsoft as the systems vendor or possibly a third party that provides security tools. Luckily for my application we are dealing with a authenticated and validated users so the user base is fairly well known, and relatively small - this is not a wide open Internet application that's directly public facing. As I mentioned earlier in the post, if I had my way I would simply not allow this type of raw HTML input in the first place, and instead rely on a more controlled HTML input mechanism like MarkDown or even a good HTML Edit control that can provide some limits on what types of input are allowed. Alas in this case I was overridden and we had to go forward and allow *any* raw HTML posted. Sometimes I really feel sad that it's come this far - how many good applications and tools have been thwarted by fear of XSS (or worse) attacks? So many things that could be done *if* we had a more secure browser experience and didn't have to deal with every little script twerp trying to hack into Web pages and obscure browser bugs. So much time wasted building secure apps, so much time wasted by others trying to hack apps… We're a funny species - no other species manages to waste as much time, effort and resources as we humans do :-) Resources Code on GitHub Html Agility Pack XSS Cheat Sheet XSS Prevention Cheat Sheet Microsoft Web Protection Library (AntiXss) StackOverflow Links: http://stackoverflow.com/questions/341872/html-sanitizer-for-net http://blog.stackoverflow.com/2008/06/safe-html-and-xss/ http://code.google.com/p/subsonicforums/source/browse/trunk/SubSonic.Forums.Data/HtmlScrubber.cs?r=61© Rick Strahl, West Wind Technologies, 2005-2012Posted in Security  HTML  ASP.NET  JavaScript   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Using JSON.NET for dynamic JSON parsing

  - by Rick Strahl

  With the release of ASP.NET Web API as part of .NET 4.5 and MVC 4.0, JSON.NET has effectively pushed out the .NET native serializers to become the default serializer for Web API. JSON.NET is vastly more flexible than the built in DataContractJsonSerializer or the older JavaScript serializer. The DataContractSerializer in particular has been very problematic in the past because it can't deal with untyped objects for serialization - like values of type object, or anonymous types which are quite common these days. The JavaScript Serializer that came before it actually does support non-typed objects for serialization but it can't do anything with untyped data coming in from JavaScript and it's overall model of extensibility was pretty limited (JavaScript Serializer is what MVC uses for JSON responses). JSON.NET provides a robust JSON serializer that has both high level and low level components, supports binary JSON, JSON contracts, Xml to JSON conversion, LINQ to JSON and many, many more features than either of the built in serializers. ASP.NET Web API now uses JSON.NET as its default serializer and is now pulled in as a NuGet dependency into Web API projects, which is great. Dynamic JSON Parsing One of the features that I think is getting ever more important is the ability to serialize and deserialize arbitrary JSON content dynamically - that is without mapping the JSON captured directly into a .NET type as DataContractSerializer or the JavaScript Serializers do. Sometimes it isn't possible to map types due to the differences in languages (think collections, dictionaries etc), and other times you simply don't have the structures in place or don't want to create them to actually import the data. If this topic sounds familiar - you're right! I wrote about dynamic JSON parsing a few months back before JSON.NET was added to Web API and when Web API and the System.Net HttpClient libraries included the System.Json classes like JsonObject and JsonArray. With the inclusion of JSON.NET in Web API these classes are now obsolete and didn't ship with Web API or the client libraries. I re-linked my original post to this one. In this post I'll discus JToken, JObject and JArray which are the dynamic JSON objects that make it very easy to create and retrieve JSON content on the fly without underlying types. Why Dynamic JSON? So, why Dynamic JSON parsing rather than strongly typed parsing? Since applications are interacting more and more with third party services it becomes ever more important to have easy access to those services with easy JSON parsing. Sometimes it just makes lot of sense to pull just a small amount of data out of large JSON document received from a service, because the third party service isn't directly related to your application's logic most of the time - and it makes little sense to map the entire service structure in your application. For example, recently I worked with the Google Maps Places API to return information about businesses close to me (or rather the app's) location. The Google API returns a ton of information that my application had no interest in - all I needed was few values out of the data. Dynamic JSON parsing makes it possible to map this data, without having to map the entire API to a C# data structure. Instead I could pull out the three or four values I needed from the API and directly store it on my business entities that needed to receive the data - no need to map the entire Maps API structure. Getting JSON.NET The easiest way to use JSON.NET is to grab it via NuGet and add it as a reference to your project. You can add it to your project with: PM> Install-Package Newtonsoft.Json From the Package Manager Console or by using Manage NuGet Packages in your project References. As mentioned if you're using ASP.NET Web API or MVC 4 JSON.NET will be automatically added to your project. Alternately you can also go to the CodePlex site and download the latest version including source code: http://json.codeplex.com/ Creating JSON on the fly with JObject and JArray Let's start with creating some JSON on the fly. It's super easy to create a dynamic object structure with any of the JToken derived JSON.NET objects. The most common JToken derived classes you are likely to use are JObject and JArray. JToken implements IDynamicMetaProvider and so uses the dynamic  keyword extensively to make it intuitive to create object structures and turn them into JSON via dynamic object syntax. Here's an example of creating a music album structure with child songs using JObject for the base object and songs and JArray for the actual collection of songs:[TestMethod] public void JObjectOutputTest() { // strong typed instance var jsonObject = new JObject(); // you can explicitly add values here using class interface jsonObject.Add("Entered", DateTime.Now); // or cast to dynamic to dynamically add/read properties dynamic album = jsonObject; album.AlbumName = "Dirty Deeds Done Dirt Cheap"; album.Artist = "AC/DC"; album.YearReleased = 1976; album.Songs = new JArray() as dynamic; dynamic song = new JObject(); song.SongName = "Dirty Deeds Done Dirt Cheap"; song.SongLength = "4:11"; album.Songs.Add(song); song = new JObject(); song.SongName = "Love at First Feel"; song.SongLength = "3:10"; album.Songs.Add(song); Console.WriteLine(album.ToString()); } This produces a complete JSON structure: { "Entered": "2012-08-18T13:26:37.7137482-10:00", "AlbumName": "Dirty Deeds Done Dirt Cheap", "Artist": "AC/DC", "YearReleased": 1976, "Songs": [ { "SongName": "Dirty Deeds Done Dirt Cheap", "SongLength": "4:11" }, { "SongName": "Love at First Feel", "SongLength": "3:10" } ] } Notice that JSON.NET does a nice job formatting the JSON, so it's easy to read and paste into blog posts :-). JSON.NET includes a bunch of configuration options that control how JSON is generated. Typically the defaults are just fine, but you can override with the JsonSettings object for most operations. The important thing about this code is that there's no explicit type used for holding the values to serialize to JSON. Rather the JSON.NET objects are the containers that receive the data as I build up my JSON structure dynamically, simply by adding properties. This means this code can be entirely driven at runtime without compile time restraints of structure for the JSON output. Here I use JObject to create a album 'object' and immediately cast it to dynamic. JObject() is kind of similar in behavior to ExpandoObject in that it allows you to add properties by simply assigning to them. Internally, JObject values are stored in pseudo collections of key value pairs that are exposed as properties through the IDynamicMetaObject interface exposed in JSON.NET's JToken base class. For objects the syntax is very clean - you add simple typed values as properties. For objects and arrays you have to explicitly create new JObject or JArray, cast them to dynamic and then add properties and items to them. Always remember though these values are dynamic - which means no Intellisense and no compiler type checking. It's up to you to ensure that the names and values you create are accessed consistently and without typos in your code. Note that you can also access the JObject instance directly (not as dynamic) and get access to the underlying JObject type. This means you can assign properties by string, which can be useful for fully data driven JSON generation from other structures. Below you can see both styles of access next to each other:// strong type instance var jsonObject = new JObject(); // you can explicitly add values here jsonObject.Add("Entered", DateTime.Now); // expando style instance you can just 'use' properties dynamic album = jsonObject; album.AlbumName = "Dirty Deeds Done Dirt Cheap"; JContainer (the base class for JObject and JArray) is a collection so you can also iterate over the properties at runtime easily:foreach (var item in jsonObject) { Console.WriteLine(item.Key + " " + item.Value.ToString()); } The functionality of the JSON objects are very similar to .NET's ExpandObject and if you used it before, you're already familiar with how the dynamic interfaces to the JSON objects works. Importing JSON with JObject.Parse() and JArray.Parse() The JValue structure supports importing JSON via the Parse() and Load() methods which can read JSON data from a string or various streams respectively. Essentially JValue includes the core JSON parsing to turn a JSON string into a collection of JsonValue objects that can be then referenced using familiar dynamic object syntax. Here's a simple example:public void JValueParsingTest() { var jsonString = @"{""Name"":""Rick"",""Company"":""West Wind"", ""Entered"":""2012-03-16T00:03:33.245-10:00""}"; dynamic json = JValue.Parse(jsonString); // values require casting string name = json.Name; string company = json.Company; DateTime entered = json.Entered; Assert.AreEqual(name, "Rick"); Assert.AreEqual(company, "West Wind"); } The JSON string represents an object with three properties which is parsed into a JObject class and cast to dynamic. Once cast to dynamic I can then go ahead and access the object using familiar object syntax. Note that the actual values - json.Name, json.Company, json.Entered - are actually of type JToken and I have to cast them to their appropriate types first before I can do type comparisons as in the Asserts at the end of the test method. This is required because of the way that dynamic types work which can't determine the type based on the method signature of the Assert.AreEqual(object,object) method. I have to either assign the dynamic value to a variable as I did above, or explicitly cast ( (string) json.Name) in the actual method call. The JSON structure can be much more complex than this simple example. Here's another example of an array of albums serialized to JSON and then parsed through with JsonValue():[TestMethod] public void JsonArrayParsingTest() { var jsonString = @"[ { ""Id"": ""b3ec4e5c"", ""AlbumName"": ""Dirty Deeds Done Dirt Cheap"", ""Artist"": ""AC/DC"", ""YearReleased"": 1976, ""Entered"": ""2012-03-16T00:13:12.2810521-10:00"", ""AlbumImageUrl"": ""http://ecx.images-amazon.com/images/I/61kTaH-uZBL._AA115_.jpg"", ""AmazonUrl"": ""http://www.amazon.com/gp/product/…ASIN=B00008BXJ4"", ""Songs"": [ { ""AlbumId"": ""b3ec4e5c"", ""SongName"": ""Dirty Deeds Done Dirt Cheap"", ""SongLength"": ""4:11"" }, { ""AlbumId"": ""b3ec4e5c"", ""SongName"": ""Love at First Feel"", ""SongLength"": ""3:10"" }, { ""AlbumId"": ""b3ec4e5c"", ""SongName"": ""Big Balls"", ""SongLength"": ""2:38"" } ] }, { ""Id"": ""7b919432"", ""AlbumName"": ""End of the Silence"", ""Artist"": ""Henry Rollins Band"", ""YearReleased"": 1992, ""Entered"": ""2012-03-16T00:13:12.2800521-10:00"", ""AlbumImageUrl"": ""http://ecx.images-amazon.com/images/I/51FO3rb1tuL._SL160_AA160_.jpg"", ""AmazonUrl"": ""http://www.amazon.com/End-Silence-Rollins-Band/dp/B0000040OX/ref=sr_1_5?ie=UTF8&qid=1302232195&sr=8-5"", ""Songs"": [ { ""AlbumId"": ""7b919432"", ""SongName"": ""Low Self Opinion"", ""SongLength"": ""5:24"" }, { ""AlbumId"": ""7b919432"", ""SongName"": ""Grip"", ""SongLength"": ""4:51"" } ] } ]"; JArray jsonVal = JArray.Parse(jsonString) as JArray; dynamic albums = jsonVal; foreach (dynamic album in albums) { Console.WriteLine(album.AlbumName + " (" + album.YearReleased.ToString() + ")"); foreach (dynamic song in album.Songs) { Console.WriteLine("\t" + song.SongName); } } Console.WriteLine(albums[0].AlbumName); Console.WriteLine(albums[0].Songs[1].SongName); } JObject and JArray in ASP.NET Web API Of course these types also work in ASP.NET Web API controller methods. If you want you can accept parameters using these object or return them back to the server. The following contrived example receives dynamic JSON input, and then creates a new dynamic JSON object and returns it based on data from the first:[HttpPost] public JObject PostAlbumJObject(JObject jAlbum) { // dynamic input from inbound JSON dynamic album = jAlbum; // create a new JSON object to write out dynamic newAlbum = new JObject(); // Create properties on the new instance // with values from the first newAlbum.AlbumName = album.AlbumName + " New"; newAlbum.NewProperty = "something new"; newAlbum.Songs = new JArray(); foreach (dynamic song in album.Songs) { song.SongName = song.SongName + " New"; newAlbum.Songs.Add(song); } return newAlbum; } The raw POST request to the server looks something like this: POST http://localhost/aspnetwebapi/samples/PostAlbumJObject HTTP/1.1User-Agent: FiddlerContent-type: application/jsonHost: localhostContent-Length: 88 {AlbumName: "Dirty Deeds",Songs:[ { SongName: "Problem Child"},{ SongName: "Squealer"}]} and the output that comes back looks like this: {  "AlbumName": "Dirty Deeds New",  "NewProperty": "something new",  "Songs": [    {      "SongName": "Problem Child New"    },    {      "SongName": "Squealer New"    }  ]} The original values are echoed back with something extra appended to demonstrate that we're working with a new object. When you receive or return a JObject, JValue, JToken or JArray instance in a Web API method, Web API ignores normal content negotiation and assumes your content is going to be received and returned as JSON, so effectively the parameter and result type explicitly determines the input and output format which is nice. Dynamic to Strong Type Mapping You can also map JObject and JArray instances to a strongly typed object, so you can mix dynamic and static typing in the same piece of code. Using the 2 Album jsonString shown earlier, the code below takes an array of albums and picks out only a single album and casts that album to a static Album instance.[TestMethod] public void JsonParseToStrongTypeTest() { JArray albums = JArray.Parse(jsonString) as JArray; // pick out one album JObject jalbum = albums[0] as JObject; // Copy to a static Album instance Album album = jalbum.ToObject<Album>(); Assert.IsNotNull(album); Assert.AreEqual(album.AlbumName,jalbum.Value<string>("AlbumName")); Assert.IsTrue(album.Songs.Count > 0); } This is pretty damn useful for the scenario I mentioned earlier - you can read a large chunk of JSON and dynamically walk the property hierarchy down to the item you want to access, and then either access the specific item dynamically (as shown earlier) or map a part of the JSON to a strongly typed object. That's very powerful if you think about it - it leaves you in total control to decide what's dynamic and what's static. Strongly typed JSON Parsing With all this talk of dynamic let's not forget that JSON.NET of course also does strongly typed serialization which is drop dead easy. Here's a simple example on how to serialize and deserialize an object with JSON.NET:[TestMethod] public void StronglyTypedSerializationTest() { // Demonstrate deserialization from a raw string var album = new Album() { AlbumName = "Dirty Deeds Done Dirt Cheap", Artist = "AC/DC", Entered = DateTime.Now, YearReleased = 1976, Songs = new List<Song>() { new Song() { SongName = "Dirty Deeds Done Dirt Cheap", SongLength = "4:11" }, new Song() { SongName = "Love at First Feel", SongLength = "3:10" } } }; // serialize to string string json2 = JsonConvert.SerializeObject(album,Formatting.Indented); Console.WriteLine(json2); // make sure we can serialize back var album2 = JsonConvert.DeserializeObject<Album>(json2); Assert.IsNotNull(album2); Assert.IsTrue(album2.AlbumName == "Dirty Deeds Done Dirt Cheap"); Assert.IsTrue(album2.Songs.Count == 2); } JsonConvert is a high level static class that wraps lower level functionality, but you can also use the JsonSerializer class, which allows you to serialize/parse to and from streams. It's a little more work, but gives you a bit more control. The functionality available is easy to discover with Intellisense, and that's good because there's not a lot in the way of documentation that's actually useful. Summary JSON.NET is a pretty complete JSON implementation with lots of different choices for JSON parsing from dynamic parsing to static serialization, to complex querying of JSON objects using LINQ. It's good to see this open source library getting integrated into .NET, and pushing out the old and tired stock .NET parsers so that we finally have a bit more flexibility - and extensibility - in our JSON parsing. Good to go! Resources Sample Test Project http://json.codeplex.com/© Rick Strahl, West Wind Technologies, 2005-2012Posted in .NET  Web Api  AJAX   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Using an alternate JSON Serializer in ASP.NET Web API

  - by Rick Strahl

  The new ASP.NET Web API that Microsoft released alongside MVC 4.0 Beta last week is a great framework for building REST and AJAX APIs. I've been working with it for quite a while now and I really like the way it works and the complete set of features it provides 'in the box'. It's about time that Microsoft gets a decent API for building generic HTTP endpoints into the framework. DataContractJsonSerializer sucks As nice as Web API's overall design is one thing still sucks: The built-in JSON Serialization uses the DataContractJsonSerializer which is just too limiting for many scenarios. The biggest issues I have with it are: No support for untyped values (object, dynamic, Anonymous Types) MS AJAX style Date Formatting Ugly serialization formats for types like Dictionaries To me the most serious issue is dealing with serialization of untyped objects. I have number of applications with AJAX front ends that dynamically reformat data from business objects to fit a specific message format that certain UI components require. The most common scenario I have there are IEnumerable query results from a database with fields from the result set rearranged to fit the sometimes unconventional formats required for the UI components (like jqGrid for example). Creating custom types to fit these messages seems like overkill and projections using Linq makes this much easier to code up. Alas DataContractJsonSerializer doesn't support it. Neither does DataContractSerializer for XML output for that matter. What this means is that you can't do stuff like this in Web API out of the box:public object GetAnonymousType() { return new { name = "Rick", company = "West Wind", entered= DateTime.Now }; } Basically anything that doesn't have an explicit type DataContractJsonSerializer will not let you return. FWIW, the same is true for XmlSerializer which also doesn't work with non-typed values for serialization. The example above is obviously contrived with a hardcoded object graph, but it's not uncommon to get dynamic values returned from queries that have anonymous types for their result projections. Apparently there's a good possibility that Microsoft will ship Json.NET as part of Web API RTM release.  Scott Hanselman confirmed this as a footnote in his JSON Dates post a few days ago. I've heard several other people from Microsoft confirm that Json.NET will be included and be the default JSON serializer, but no details yet in what capacity it will show up. Let's hope it ends up as the default in the box. Meanwhile this post will show you how you can use it today with the beta and get JSON that matches what you should see in the RTM version. What about JsonValue? To be fair Web API DOES include a new JsonValue/JsonObject/JsonArray type that allow you to address some of these scenarios. JsonValue is a new type in the System.Json assembly that can be used to build up an object graph based on a dictionary. It's actually a really cool implementation of a dynamic type that allows you to create an object graph and spit it out to JSON without having to create .NET type first. JsonValue can also receive a JSON string and parse it without having to actually load it into a .NET type (which is something that's been missing in the core framework). This is really useful if you get a JSON result from an arbitrary service and you don't want to explicitly create a mapping type for the data returned. For serialization you can create an object structure on the fly and pass it back as part of an Web API action method like this:public JsonValue GetJsonValue() { dynamic json = new JsonObject(); json.name = "Rick"; json.company = "West Wind"; json.entered = DateTime.Now; dynamic address = new JsonObject(); address.street = "32 Kaiea"; address.zip = "96779"; json.address = address; dynamic phones = new JsonArray(); json.phoneNumbers = phones; dynamic phone = new JsonObject(); phone.type = "Home"; phone.number = "808 123-1233"; phones.Add(phone); phone = new JsonObject(); phone.type = "Home"; phone.number = "808 123-1233"; phones.Add(phone); //var jsonString = json.ToString(); return json; } which produces the following output (formatted here for easier reading):{ name: "rick", company: "West Wind", entered: "2012-03-08T15:33:19.673-10:00", address: { street: "32 Kaiea", zip: "96779" }, phoneNumbers: [ { type: "Home", number: "808 123-1233" }, { type: "Mobile", number: "808 123-1234" }] } If you need to build a simple JSON type on the fly these types work great. But if you have an existing type - or worse a query result/list that's already formatted JsonValue et al. become a pain to work with. As far as I can see there's no way to just throw an object instance at JsonValue and have it convert into JsonValue dictionary. It's a manual process. Using alternate Serializers in Web API So, currently the default serializer in WebAPI is DataContractJsonSeriaizer and I don't like it. You may not either, but luckily you can swap the serializer fairly easily. If you'd rather use the JavaScriptSerializer built into System.Web.Extensions or Json.NET today, it's not too difficult to create a custom MediaTypeFormatter that uses these serializers and can replace or partially replace the native serializer. Here's a MediaTypeFormatter implementation using the ASP.NET JavaScriptSerializer:using System; using System.Net.Http.Formatting; using System.Threading.Tasks; using System.Web.Script.Serialization; using System.Json; using System.IO; namespace Westwind.Web.WebApi { public class JavaScriptSerializerFormatter : MediaTypeFormatter { public JavaScriptSerializerFormatter() { SupportedMediaTypes.Add(new System.Net.Http.Headers.MediaTypeHeaderValue("application/json")); } protected override bool CanWriteType(Type type) { // don't serialize JsonValue structure use default for that if (type == typeof(JsonValue) || type == typeof(JsonObject) || type== typeof(JsonArray) ) return false; return true; } protected override bool CanReadType(Type type) { if (type == typeof(IKeyValueModel)) return false; return true; } protected override System.Threading.Tasks.Taskobject OnReadFromStreamAsync(Type type, System.IO.Stream stream, System.Net.Http.Headers.HttpContentHeaders contentHeaders, FormatterContext formatterContext) { var task = Taskobject.Factory.StartNew(() = { var ser = new JavaScriptSerializer(); string json; using (var sr = new StreamReader(stream)) { json = sr.ReadToEnd(); sr.Close(); } object val = ser.Deserialize(json,type); return val; }); return task; } protected override System.Threading.Tasks.Task OnWriteToStreamAsync(Type type, object value, System.IO.Stream stream, System.Net.Http.Headers.HttpContentHeaders contentHeaders, FormatterContext formatterContext, System.Net.TransportContext transportContext) { var task = Task.Factory.StartNew( () = { var ser = new JavaScriptSerializer(); var json = ser.Serialize(value); byte[] buf = System.Text.Encoding.Default.GetBytes(json); stream.Write(buf,0,buf.Length); stream.Flush(); }); return task; } } } Formatter implementation is pretty simple: You override 4 methods to tell which types you can handle and then handle the input or output streams to create/parse the JSON data. Note that when creating output you want to take care to still allow JsonValue/JsonObject/JsonArray types to be handled by the default serializer so those objects serialize properly - if you let either JavaScriptSerializer or JSON.NET handle them they'd try to render the dictionaries which is very undesirable. If you'd rather use Json.NET here's the JSON.NET version of the formatter:// this code requires a reference to JSON.NET in your project #if true using System; using System.Net.Http.Formatting; using System.Threading.Tasks; using System.Web.Script.Serialization; using System.Json; using Newtonsoft.Json; using System.IO; using Newtonsoft.Json.Converters; namespace Westwind.Web.WebApi { public class JsonNetFormatter : MediaTypeFormatter { public JsonNetFormatter() { SupportedMediaTypes.Add(new System.Net.Http.Headers.MediaTypeHeaderValue("application/json")); } protected override bool CanWriteType(Type type) { // don't serialize JsonValue structure use default for that if (type == typeof(JsonValue) || type == typeof(JsonObject) || type == typeof(JsonArray)) return false; return true; } protected override bool CanReadType(Type type) { if (type == typeof(IKeyValueModel)) return false; return true; } protected override System.Threading.Tasks.Taskobject OnReadFromStreamAsync(Type type, System.IO.Stream stream, System.Net.Http.Headers.HttpContentHeaders contentHeaders, FormatterContext formatterContext) { var task = Taskobject.Factory.StartNew(() = { var settings = new JsonSerializerSettings() { NullValueHandling = NullValueHandling.Ignore, }; var sr = new StreamReader(stream); var jreader = new JsonTextReader(sr); var ser = new JsonSerializer(); ser.Converters.Add(new IsoDateTimeConverter()); object val = ser.Deserialize(jreader, type); return val; }); return task; } protected override System.Threading.Tasks.Task OnWriteToStreamAsync(Type type, object value, System.IO.Stream stream, System.Net.Http.Headers.HttpContentHeaders contentHeaders, FormatterContext formatterContext, System.Net.TransportContext transportContext) { var task = Task.Factory.StartNew( () = { var settings = new JsonSerializerSettings() { NullValueHandling = NullValueHandling.Ignore, }; string json = JsonConvert.SerializeObject(value, Formatting.Indented, new JsonConverter[1] { new IsoDateTimeConverter() } ); byte[] buf = System.Text.Encoding.Default.GetBytes(json); stream.Write(buf,0,buf.Length); stream.Flush(); }); return task; } } } #endif   One advantage of the Json.NET serializer is that you can specify a few options on how things are formatted and handled. You get null value handling and you can plug in the IsoDateTimeConverter which is nice to product proper ISO dates that I would expect any Json serializer to output these days. Hooking up the Formatters Once you've created the custom formatters you need to enable them for your Web API application. To do this use the GlobalConfiguration.Configuration object and add the formatter to the Formatters collection. Here's what this looks like hooked up from Application_Start in a Web project:protected void Application_Start(object sender, EventArgs e) { // Action based routing (used for RPC calls) RouteTable.Routes.MapHttpRoute( name: "StockApi", routeTemplate: "stocks/{action}/{symbol}", defaults: new { symbol = RouteParameter.Optional, controller = "StockApi" } ); // WebApi Configuration to hook up formatters and message handlers // optional RegisterApis(GlobalConfiguration.Configuration); } public static void RegisterApis(HttpConfiguration config) { // Add JavaScriptSerializer formatter instead - add at top to make default //config.Formatters.Insert(0, new JavaScriptSerializerFormatter()); // Add Json.net formatter - add at the top so it fires first! // This leaves the old one in place so JsonValue/JsonObject/JsonArray still are handled config.Formatters.Insert(0, new JsonNetFormatter()); } One thing to remember here is the GlobalConfiguration object which is Web API's static configuration instance. I think this thing is seriously misnamed given that GlobalConfiguration could stand for anything and so is hard to discover if you don't know what you're looking for. How about WebApiConfiguration or something more descriptive? Anyway, once you know what it is you can use the Formatters collection to insert your custom formatter. Note that I insert my formatter at the top of the list so it takes precedence over the default formatter. I also am not removing the old formatter because I still want JsonValue/JsonObject/JsonArray to be handled by the default serialization mechanism. Since they process in sequence and I exclude processing for these types JsonValue et al. still get properly serialized/deserialized. Summary Currently DataContractJsonSerializer in Web API is a pain, but at least we have the ability with relatively limited effort to replace the MediaTypeFormatter and plug in our own JSON serializer. This is useful for many scenarios - if you have existing client applications that used MVC JsonResult or ASP.NET AJAX results from ASMX AJAX services you can plug in the JavaScript serializer and get exactly the same serializer you used in the past so your results will be the same and don't potentially break clients. JSON serializers do vary a bit in how they serialize some of the more complex types (like Dictionaries and dates for example) and so if you're migrating it might be helpful to ensure your client code doesn't break when you switch to ASP.NET Web API. Going forward it looks like Microsoft is planning on plugging in Json.Net into Web API and make that the default. I think that's an awesome choice since Json.net has been around forever, is fast and easy to use and provides a ton of functionality as part of this great library. I just wish Microsoft would have figured this out sooner instead of now at the last minute integrating with it especially given that Json.Net has a similar set of lower level JSON objects JsonValue/JsonObject etc. which now will end up being duplicated by the native System.Json stuff. It's not like we don't already have enough confusion regarding which JSON serializer to use (JavaScriptSerializer, DataContractJsonSerializer, JsonValue/JsonObject/JsonArray and now Json.net). For years I've been using my own JSON serializer because the built in choices are both limited. However, with an official encorsement of Json.Net I'm happily moving on to use that in my applications. Let's see and hope Microsoft gets this right before ASP.NET Web API goes gold.© Rick Strahl, West Wind Technologies, 2005-2012Posted in Web Api  AJAX  ASP.NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• UISplitViewController in a TabBar ( UITabBarController )?

  - by Madhup

  Hi all, I am in kind of situation that I need to start with a tab based application and in that I need a split view for one or more tabs. But it seems that split view controller object can not be added to the tabbarController. (Although tabbar object can be added to the splitviewcontroller). The problem can be seen otherways: I have a full screen in the left part I have a table view when any row is selected in the table a popover should come out pointing that row. Now when any row in the popover is selected the rows in this popover comes to the left under the selected row (only this row would be visible) and another popover comes out from the selected row. (Breadcrumb navigation type) I think I am clear in what I explained. So guys any ideas or work arounds? Please let me know if I am not clear in my question. Thanks, Madhup

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