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• How to allow the user to select an input file for my SQL AdventureWorks web application?

  - by salvationishere

  I have a SQL and VS 2008 web application that I need to capture the full file path (directories and file name) from the selected file on the client computer. So user selects a file and then clicks on one of the buttons which transfers control to my code for processing. So how do I get its file path? I can get the file name, but not the path. Maybe problem is that while testing this web app, I am using the server instead of client machine. And I learned that on a server you cannot read the full file path due to security concerns. Is this true? If I just want this to work on client machine, which method/class do you recommend? And then how can I test it? My web app allows the user to select an input file and then map columns from the input .MDF file with columns from the selected Adventureworks table. Finally, after they click on the "Append" button, it adds rows from the input file to that table. So I want to capture the path info after they click this button.

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• div innerHTML problem with updatepanel

  - by asif

  I have an application developed in asp.net which set innerhtml of div. I am creating an html string to show googlemap. It works fine. But when I put my div inside update panel. it doesnt show googlemap in div. Here is my aspx file code: </td> </tr> <tr> <td colspan="4"> <asp:UpdatePanel ID="UpdatePanel2" runat="server"> <ContentTemplate> <div id="map_canvas" runat="server" style="width: 100%; height: 1500px; margin-bottom: 2px; text-align: center;"> <asp:Panel ID="Panel1" runat="server"> <%--Place holder to fill with javascript by server side code--%> <asp:Literal ID="js" runat="server"></asp:Literal> <%--Place for google to show your MAP--%> <div id="Div1" style="width: 100%; height: 728px; margin-bottom: 2px;"> </div> <br /> </asp:Panel> </div> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="btnShow" EventName="Click" /> </Triggers> </asp:UpdatePanel> </td> </tr> here is my button click event. protected void btnShow_Click(object sender, EventArgs e) { // works fine without update panel. map_canvas.InnerHtml = showMapWithPoints(); }

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• Ember model is gone when I use the renderTemplate hook

  - by Mickael Caruso

  I have a single template - editPerson.hbs <form role="form"> FirstName: {{input type="text" value=model.firstName }} <br/> LastName: {{input type="text" value=model.lastName }} </form> I want to render this template when the user wants to edit an existing person or create a new person. So, I set up routes: App.Router.map(function(){ this.route("createPerson", { path: "/person/new" }); this.route("editPerson", { path: "/person/:id}); // other routes not show for brevity }); So, I define two routes - one for create and one for edit: App.CreatePersonRoute = Ember.Route.extend({ renderTemplate: function(){ this.render("editPerson", { controller: "editPerson" }); }, model: function(){ return {firstName: "John", lastName: "Smith" }; } }); App.EditPersonRoute = Ember.Route.extend({ model: function(id){ return {firstName: "John Existing", lastName: "Smith Existing" }; } }); So, I hard-code the models. I'm concerned about the createPerson route. I'm telling it to render the editPersonTemplate and to use the editPerson controller (which I don't show because I don't think it matters - but I made one, though.) When I use renderTemplate, I lose the model John Smith, which in turn, won't display on the editTemplate on the web page. Why? I "fixed" this by creating a separate and identical (to editPerson.hbs) createPerson.hbs, and removing the renderTemplate hook in the CreatePerson. It works as expected, but I find it somewhat troubling to have a separate and identical template for the edit and create cases. I looked everywhere for how to properly do this, and I found no answers.

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• Routing trouble for RESTful API - Rails

  - by aressidi

  I'm building out an API for web app that I've been working on for some time. I've started with the User model. The user portion of the API will allow remote clients to a) retrieve user data, b) update user information and c) create new users. I've gotten all of this to work, but it doesn't seem like its setup correctly. Here are my questions: Should the API endpoint be users or user? What's the best practice? I have to add the action to the end, which I would expect to be picked up instead by the request type so I don't have to specify it explicitly. How do I get my routes setup properly as not to have to include the method for protected actions? Let me give some examples: Get request for show - want it to work without the "show" curl -u rmbruno:blah http://app.local/api/users/show Put request for update - want it to work without the "update" curl -X put -F 'user[forum_notifications]=true' -u rmbruno:blah http://app.local/api/users/update Create - works with or without 'create' which is what I want for all these actions curl -X post -F 'user[login]=mamafatta' -F 'user[email][email protected]' -F 'user[password]=12345678' http://twye.local/api/users/ How do I structure routes to not require the action name? Isn't that the common way to to RESTful APIs? Here is my route for the API now: map.namespace :api do |route| route.resources :users route.resources :weight end I'm using restful authentication which is handling the http auth in curl. Any guidance on the routes issues and best practice on singular versus plural would be really helpful. Thanks! -A

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• iphone SDK buttons control views

  - by mangnv

  Hi, all I'v just started to learn SDK. I have several questions. First. I will do the project about university APP. if u clike the app, then u can c several buttons on one page, then each button( eg: event, BBS,courses, map....) has specific function...each one connect to anohter view. Are they buttons on the main page? Second, how to deal with one view has several buttons, one button connect to other view? Third, how to deal with controller classes? I'd like to make a app like this way. Main Page has 6 buttonss(event, community, directory...), take community for eg: community has two functions( Notices and BBS). if i clike Notices, then i can read notices, and if i clike BBS, then i could also read BBS. The thing that i do not get is..how to deal with classes. I mean main Page has one controller classes that control 6 buttons? If my question is not so clearly, then let me know....I really need help~

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• Extand legacy site with another server-side programming platform best practice

  - by Andrew Florko

  Company I work for have a site developed 6-8 years ago by a team that was enthusiastic enough to use their own private PHP-based CMS. I have to put dynamic data from one intranet company database on this site in one week: 2-3 pages. I contacted company site administrator and she showed me administrative part - CMS allows only to insert html blocks & manage site map (site is deployed on machine that is inside company & fully accessible & upgradable). I'm not a PHP-guy & I don't want to dive into legacy hardly-who-ever-heard-about CMS engine I also don't want to contact developers team, 'cos I'm not sure they are still present and capable enough to extend this old days site and it'll take too much time anyway. I am about to deploy helper asp.net site on iis with 2-3 pages required & refer helper site via iframe from present site. New pages will allow to download some dynamic content from present site also. Is it ok and what are the pitfalls with iframe approach?

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• Query Level 2 Caching throwing ClassCastException

  - by Sameer Malhotra

  Hi, I am using JPA and Hibernate for the database. I have configured (EHCacache) second level cache and query level cache, but just to make sure that caching is working I was trying to get the statistics which is throwing class cast exception.Any help will be highly appreciated. My main goal is to see all the objects which have been cached to make sure that the caching is working properly. Here is the code: public List<CodeValue> findByCodetype(String propertyName) { try { final String queryString = "select model from CodeValue model where model.codetype" + "= :propertyValue" + " order by model.code"; Query query = em.createQuery(queryString); query.setHint("org.hibernate.cacheable", true); query.setHint("org.hibernate.cacheRegion", "query.findByCodetype"); query.setParameter("propertyValue", propertyName); List resultList = query.getResultList(); org.hibernate.Session session = (Session) em.getDelegate(); SessionFactory sessionFactory = session.getSessionFactory(); Map cacheEntries = sessionFactory.getStatistics() .getSecondLevelCacheStatistics("query.findByCodetype") .getEntries(); logger.info("The statistics are: " + cacheEntries); return resultList; } catch (RuntimeException re) { logger.error("findByCodetype failed in trauma patient", re); throw re; } } The error is existing right when I am trying to print the statistics. Below is exception: [6/7/10 19:23:17:059 GMT] 00000034 SystemOut O java.lang.ClassCastException: org.hibernate.cache.QueryKey incompatible with org.hibernate.cache.CacheKey at org.hibernate.stat.SecondLevelCacheStatistics.getEntries(SecondLevelCacheStatistics.java:51) at com.idph.trauma.registry.service.TraumaPatientDAO.findByCodetype(TraumaPatientDAO.java:439) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:615) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) at $Proxy209.findByCodetype(Unknown Source) Do you know what's going on?

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• Best practice for writing ARRAYS

  - by Douglas

  I've got an array with about 250 entries in it, each their own array of values. Each entry is a point on a map, and each array holds info for: name, another array for points this point can connect to, latitude, longitude, short for of name, a boolean, and another boolean The array has been written by another developer in my team, and he has written it as such: names[0]=new Array; names[0][0]="Campus Ice Centre"; names[0][1]= new Array(0,1,2); names[0][2]=43.95081811364498; names[0][3]=-78.89848709106445; names[0][4]="CIC"; names[0][5]=false; names[0][6]=false; names[1]=new Array; names[1][0]="Shagwell's"; names[1][1]= new Array(0,1); names[1][2]=43.95090307839151; names[1][3]=-78.89815986156464; names[1][4]="shg"; names[1][5]=false; names[1][6]=false; Where I would probably have personally written it like this: var names = [] names[0] = new Array("Campus Ice Centre", new Array[0,1,2], 43.95081811364498, -78.89848709106445, "CIC", false, false); names[1] = new Array("Shagwell's", new Array[0,1], 43.95090307839151, -78.89815986156464, 'shg", false, false); They both work perfectly fine of course, but what I'm wondering is: 1) does one take longer than the other to actually process? 2) am I incorrect in assuming there is a benefit to the compactness of my version of the same thing? I'm just a little worried about his 3000 lines of code versus my 3-400 to get the same result. Thanks in advance for any guidance.

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• Python multiprocessing doesn't play nicely with uuid.uuid4().

  - by yig

  I'm trying to generate a uuid for a filename, and I'm also using the multiprocessing module. Unpleasantly, all of my uuids end up exactly the same. Here is a small example: import multiprocessing import uuid def get_uuid( a ): ## Doesn't help to cycle through a bunch. #for i in xrange(10): uuid.uuid4() ## Doesn't help to reload the module. #reload( uuid ) ## Doesn't help to load it at the last minute. ## (I simultaneously comment out the module-level import). #import uuid ## uuid1() does work, but it differs only in the first 8 characters and includes identifying information about the computer. #return uuid.uuid1() return uuid.uuid4() def main(): pool = multiprocessing.Pool( 20 ) uuids = pool.map( get_uuid, range( 20 ) ) for id in uuids: print id if __name__ == '__main__': main() I peeked into uuid.py's code, and it seems to depending-on-the-platform use some OS-level routines for randomness, so I'm stumped as to a python-level solution (to do something like reload the uuid module or choose a new random seed). I could use uuid.uuid1(), but only 8 digits differ and I think there are derived exclusively from the time, which seems dangerous especially given that I'm multiprocessing (so the code could be executing at exactly the same time). Is there some Wisdom out there about this issue?

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• php - replace array elements with another array's elements?

  - by Simpson88Keys

  Not sure how to go about this... But, I have two arrays, one with updated information, another with outdated information... There are a lot more elements in the second array, but I'm looking to "update" the outdated one with the updated information. Here's what the arrays look like: //Outdated Array ( [0] => Array ( [anum] => 3236468462 [cid] => 4899097762 [mid] => 1104881401 [na_title] => [na_fname] => JOHN [m_initial] => [na_lname] => DOE [na_suffix] => [na_addr1] => 1234 SAMPLE AVENUE [na_addr2] => [na_city] => NORWALK [state] => OH [zip] => [zip_plus_4] => [route] => R002 [dma_code] => 510334 ) ) //Updated Array ( [1] => Array ( [0] => YUD990 [1] => 98 [2] => 1234 Sample Avenue [3] => [4] => Norwalk [5] => OH [6] => 44857-9215 [7] => 3236468462 ) ) To clarify, I want to: (1) Match up the value for [7] from the updated array with the value for [anum] in the outdated array, and then update [na_addr1], [na_addr2], [na_city], [state], [zip], [zip_plus_4] in the outdated array with the values for [2],[3],[4],[5],[6] (I know I'll need to split the updated [6] in order to get it to map corrected to the outdated) Feel like I'm making this very confusing... sorry about that...

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• how to set SqlMapClient outside of spring xmls

  - by Omnipresent

  I have the following in my xml configurations. I would like to convert these to my code because I am doing some unit/integration testing outside of the container. xmls: <bean id="MyMapClient" class="org.springframework.orm.ibatis.SqlMapClientFactoryBean"> <property name="configLocation" value="classpath:sql-map-config-oracle.xml"/> <property name="dataSource" ref="IbatisDataSourceOracle"/> </bean> <bean id="IbatisDataSource" class="org.springframework.jndi.JndiObjectFactoryBean"> <property name="jndiName" value="jdbc/my/mydb"/> </bean> code I used to fetch stuff from above xmls: this.setSqlMapClient((SqlMapClient)ApplicationInitializer.getApplicationContext().getBean("MyMapClient")); my code (for unit testing purposes): SqlMapClientFactoryBean bean = new SqlMapClientFactoryBean(); UrlResource urlrc = new UrlResource("file:/data/config.xml"); bean.setConfigLocation(urlrc); DriverManagerDataSource dataSource = new DriverManagerDataSource(); dataSource.setDriverClassName("oracle.jdbc.OracleDriver"); dataSource.setUrl("jdbc:oracle:thin:@123.210.85.56:1522:ORCL"); dataSource.setUsername("dbo_mine"); dataSource.setPassword("dbo_mypwd"); bean.setDataSource(dataSource); SqlMapClient sql = (SqlMapClient) bean; //code fails here when the xml's are used then SqlMapClient is the class that sets up then how come I cant convert SqlMapClientFactoryBean to SqlMapClient

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• Why delete-orphan needs "cascade all" to run in JPA/Hibernate ?

  - by Jerome C.

  Hello, I try to map a one-to-many relation with cascade "remove" (jpa) and "delete-orphan", because I don't want children to be saved or persist when the parent is saved or persist (security reasons due to client to server (GWT, Gilead)) But this configuration doesn't work. When I try with cascade "all", it runs. Why the delete-orphan option needs a cascade "all" to run ? here is the code (without id or other fields for simplicity, the class Thread defines a simple many-to-one property without cascade): when using the removeThread function in a transactional function, it does not run but if I edit cascade.Remove into cascade.All, it runs. @Entity public class Forum { private List<ForumThread> threads; /** * @return the topics */ @OneToMany(mappedBy = "parent", cascade = CascadeType.REMOVE, fetch = FetchType.LAZY) @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN) public List<ForumThread> getThreads() { return threads; } /** * @param topics the topics to set */ public void setThreads(List<ForumThread> threads) { this.threads = threads; } public void addThread(ForumThread thread) { getThreads().add(thread); thread.setParent(this); } public void removeThread(ForumThread thread) { getThreads().remove(thread); } } thanks.

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• F# List SelectMany

  - by Tuomas Hietanen

  This is quite simple question but I didn't find an answer: Is there any Seq/List operation in F# to match the LINQ SelectMany? I know I can use System.Linq in F# if I want to. I know I can make a recursive method and use F# Computation Expressions (and make even more powerful things). But if I try to prove that F# List operations are more powerful than LINQ... .Where = List.filter .Select = List.map .Aggregate = List.fold ... In C# SelectMany usage syntax is pretty simple: var flattenedList = from i in items1 from j in items2 select ... Is there any easy direct match, List.flatten, List.bind or something like that? SelectMany has a couple of signatures, but the most complex one seems to be: IEnumerable<TResult> SelectMany<TSource, TCollection, TResult>( this IEnumerable<TSource> source, Func<TSource, IEnumerable<TCollection>> collectionSelector, Func<TSource, TCollection, TResult> resultSelector ); In F# terms this would be: ('a -> 'b list) -> ('a -> 'b -> 'c) -> 'a list -> 'c list

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• Type conversion between PHP client and Java webservice

  - by a1ex07

  I have a web service implemented as EJB. One of it's methods returns Map<String,String>. On client side I use php : $client = new SoapClient($wsdl,array("cache_wsdl"=>WSDL_CACHE_NONE)); $result = $client->foo($params); Everything works fine, but I would like $result-return to be an associative array. Now it looks like array(10) { [0]=> object(stdClass)#46 (2) { ["key"]=> string(4) "key1" ["value"]=> string(4) "val1" } .... I want array(10) {"key1"=>"value1", "key2"=>"value2", .... } The obvious solution is to iterate through this array and create a new array $arr = array(); foreach ($result->return as $val) $arr[$val->key] = $val->value; But I wonder if there is a better way to get an assosicative array ? Thanks in advance.

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• What's the standard convention for creating a new NSArray from an existing NSArray?

  - by Prairiedogg

  Let's say I have an NSArray of NSDictionaries that is 10 elements long. I want to create a second NSArray with the values for a single key on each dictionary. The best way I can figure to do this is: NSMutableArray *nameArray = [[NSMutableArray alloc] initWithCapacity:[array count]]; for (NSDictionary *p in array) { [nameArray addObject:[p objectForKey:@"name"]]; } self.my_new_array = array; [array release]; [nameArray release]; } But in theory, I should be able to get away with not using a mutable array and using a counter in conjunction with [nameArray addObjectAtIndex:count], because the new list should be exactly as long as the old list. Please note that I am NOT trying to filter for a subset of the original array, but make a new array with exactly the same number of elements, just with values dredged up from the some arbitrary attribute of each element in the array. In python one could solve this problem like this: new_list = [p['name'] for p in old_list] or if you were a masochist, like this: new_list = map(lambda p: p['name'], old_list) Having to be slightly more explicit in objective-c makes me wonder if there is an accepted common way of handling these situations.

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• Custom rowsetClass does not return values

  - by Wesley

  Hi, I'm quite new to Zend and the database classes from it. I'm having problems mapping a Zend_Db_Table_Row_Abstract to my rows. The problem is that whenever I try to map it to a class (Job) that extends the Zend_Db_Table_Row_Abstract class, the database data is not receivable anymore. I'm not getting any errors, trying to get data simply returns null. Here is my code so far: Jobs: class Jobs extends Zend_Db_Table_Abstract { protected $_name = 'jobs'; protected $_rowsetClass = "Job"; public function getActiveJobs() { $select = $this->select()->where('jobs.jobDateOpen < UNIX_TIMESTAMP()')->limit(15,0); $rows = $this->fetchAll($select); return $rows; } } Job: class Job extends Zend_Db_Table_Row_Abstract { public function getCompanyName() { //Gets the companyName } } Controller: $oJobs = new Jobs(); $aActiveJobs = $oJobs->getActiveJobs(); foreach ($aActiveJobs as $value) { var_dump($value->jobTitle); } When I remove the "protected $_rowsetClass = "Job";" line, so that the table row is not mapped to my own class, I get all the jobTitles perfectly. What am I doing wrong here? Thanks in advance, Wesley

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• Fluent Nhibernate Mapping Single class on two database tables

  - by nabeelfarid

  Hi guys, I am having problems with Mapping. I have two tables in my database as follows: Employee and EmployeeManagers Employee EmployeeId int Name nvarchar EmployeeManagers EmployeeIdFk int ManagerIdFk int So the employee can have 0 or more Managers. A manager itself is also an Employee. I have the following class to represent the Employee and Managers public class Employee { public virtual int Id { get; set; } public virtual string Name { get; set; } public virtual IList<Employee> Managers { get; protected set; } public Employee() { Managers = new List<Employee>(); } } I don't have any class to represent Manager because I think there is no need for it, as Manager itself is an Employee. I am using autoMapping and I just can't figure out how to map this class to these two tables. I am implementing IAutoMappingOverride for overriding automappings for Employee but I am not sure what to do in it. public class NodeMap : IAutoMappingOverride { public void Override(AutoMapping<Node> mapping) { //mapping.HasMany(x => x.ValidParents).Cascade.All().Table("EmployeeManager"); //mapping.HasManyToMany(x => x.ValidParents).Cascade.All().Table("EmployeeManager"); } } I also want to make sure that an employee can not be assigned the same manager twice. This is something I can verify in my application but I would like to put constraint on the EmployeeManager table (e.g. a composite key) so a same manager can not be assigned to an employee more than once. Could anyone out there help me with this please? Awaiting Nabeel

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• Routing problem with calling a new method without an ID

  - by alkaloids

  I'm trying to put together a form_tag that edits several Shift objects. I have the form built properly, and it's passing on the correct parameters. I have verified that the parameters work with updating the objects correctly in the console. However, when I click the submit button, I get the error: ActiveRecord::RecordNotFound in ShiftsController#update_individual Couldn't find Shift without an ID My route for the controller it is calling looks like this looks like this: map.resources :shifts, :collection => { :update_individual => :put } The method in ShiftsController is this: def update_individual Shift.update(params[:shifts].keys, params[:shifts].values) flash[:notice] = "Schedule saved" end The relevant form parts are these: <% form_tag( update_individual_shifts_path ) do %> ... (fields for...) <%= submit_tag "Save" %> <% end %> Why is this not working? If I browse to the url: "http://localhost:3000/shifts/update_individual/5" (or any number that corresponds to an existing shift), I get the proper error about having no parameters set, but when I pass parameters without an ID of some sort, it errors out. How do I make it stop looking for an ID at the end of the URL?

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• In IIS6, how to provide authenticated access to static files on remote server

  - by frankadelic

  We have a library of ZIP files that we would like to make available for download at an ASP.NET site. The files are sitting on a NAS device that is accessible from out web farm. Here is our initial strategy: Map an IIS virtual directory to the shared drive at path /zipfiles Users can download the zip files when given the URL However, if users share links to the files, anyone can download them. We would instead like to make use of the ASP.NET forms authentication in our site to validate users' requests before initiating the file transfer. A few problems: A request for a zip file is handled by IIS, not ASP.NET. So it is not subject to forms authentication. In addition, we don't want ASP.NET to handle the request, because it uses up an ASP.NET thread and is not scalable for download of large files. So, configuring the asp.net dll to handle *.zip requests is not an option. Any ideas on this? One idea we've tossed around is this: Initial request for download will be for an ashx handler. This handler will, after authentication, generate a download token which is saved to a database. Then, the user is redirected to the file with token appended in QueryString (e.g. /files/xyz.zip?token=123456789). An ISAPI plugin will be used to check the token. Also, the token will expire after x amount of time. Any thoughts on this? I have not implemented an ISAPI plugin so I'm not sure if this will even work. I would like to avoid custom coding since security is an issue and I'd prefer to use a time-tested solution.

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• Mapping composite foreign keys in a many-many relationship, with overlapping components.

  - by Kirk Broadhurst

  I have a Page table and a View table. There is a many-many relationship between these two via a PageView table. Unfortunately all of these tables need to have composite keys (for business reasons). Page has a primary key of (PageCode, Version), View has a primary key of (ViewCode, Version). PageView obviously enough has PageCode, ViewCode, and Version. The FK to Page is (PageCode, Version) and the FK to View is (ViewCode, Version) Makes sense and works, but when I try to map this in Entity framework I get Error 3021: Problem in mapping fragments...: Each of the following columns in table PageView is mapped to multiple conceptual side properties: PageView.Version is mapped to (PageView_Association.View.Version, PageView_Association.Page.Version) So clearly enough, EF is having a complain about the Version column being a common component of the two foreign keys. Obviously I could create a PageVersion and ViewVersion column in the join table, but that kind of defeats the point of the constraint, i.e. the Page and View must have the same Version value. Has anyone encountered this, and is there anything I can do get around it? Thanks!

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• How would the 'Model' in a Rails-type webapp be implemented in a functional programming langauge?

  - by ceptorial

  In MVC web development frameworks such as Ruby on Rails, Django, and CakePHP, HTTP requests are routed to controllers, which fetch objects which are usually persisted to a backend database store. These objects represent things like users, blog posts, etc., and often contain logic within their methods for permissions, fetching and/or mutating other objects, validation, etc. These frameworks are all very much object oriented. I've been reading up recently on functional programming and it seems to tout tremendous benefits such as testability, conciseness, modularity, etc. However most of the examples I've seen for functional programming implement trivial functionality like quicksort or the fibonnacci sequence, not complex webapps. I've looked at a few 'functional' web frameworks, and they all seem to implement the view and controller just fine, but largely skip over the whole 'model' and 'persistence' part. (I'm talking more about frameworks like Compojure which are supposed to be purely functional, versus something Lift which conveniently seems to use the OO part of Scala for the model -- but correct me if I'm wrong here.) I haven't seen a good explanation of how functional programming can be used to provide the metaphor that OO programming provides, i.e. tables map to objects, and objects can have methods which provide powerful, encapsulated logic such as permissioning and validation. Also the whole concept of using SQL queries to persist data seems to violate the whole 'side effects' concept. Could someone provide an explanation of how the 'model' layer would be implemented in a functionally programmed web framework?

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• Is it possible to store pointers in shared memory without using offsets?

  - by Joseph Garvin

  When using shared memory, each process may mmap the shared region into a different area of their address space. This means that when storing pointers within the shared region, you need to store them as offsets of the start of the shared region. Unfortunately, this complicates use of atomic instructions (e.g. if you're trying to write a lock free algorithm). For example, say you have a bunch of reference counted nodes in shared memory, created by a single writer. The writer periodically atomically updates a pointer 'p' to point to a valid node with positive reference count. Readers want to atomically write to 'p' because it points to the beginning of a node (a struct) whose first element is a reference count. Since p always points to a valid node, incrementing the ref count is safe, and makes it safe to dereference 'p' and access other members. However, this all only works when everything is in the same address space. If the nodes and the 'p' pointer are stored in shared memory, then clients suffer a race condition: x = read p y = x + offset Increment refcount at y During step 2, p may change and x may no longer point to a valid node. The only workaround I can think of is somehow forcing all processes to agree on where to map the shared memory, so that real pointers rather than offsets can be stored in the mmap'd region. Is there any way to do that? I see MAP_FIXED in the mmap documentation, but I don't know how I could pick an address that would be safe.

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• Ruby GraphViz Binary Tree Record

  - by Jason M

  I'm using the ruby-graphviz gem and I'm trying to draw binary trees. I'd like to use the record shape so that each node can have a left, middle, and right field and, thus, if there are two edges leaving a node, the left and right edges can be distinguished. I tried specifying the field by concatenating the field name like this: @node1.name + ":left" But that did not work. What is the correct way of specifying the field? require 'rubygems' require 'graphviz' @graph = GraphViz.new( :G, :type => :digraph ) @node1 = @graph.add_node("1", "shape" => "record", "label" => "<left>|<f1> 1|<right>" ) @node2 = @graph.add_node("2", "shape" => "record", "label" => "<left>|<f1> 2|<right>" ) @graph.add_edge(@node1.name + ":left", @node2) # generate a random filename filename = "/tmp/#{(0...8).map{65.+(rand(25)).chr}.join}.png" @graph.output( :png => filename ) exec "open #{filename}"

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• URL rewriting to a common end point

  - by sunil

  I want to create an asp.net white-label site http://whitelabel.com, that could be styled for each of our clients according to their specific needs. So for example, client abc would see the site in their corporate colours and be accessed through their specific url http://abc.com. Likewise client xyz would see the site in their own styling and url http://xyz.com. Typing either url, in effect, takes the user to http://whitelabel.com where the styling is applied, and the client's url structure is retained. I was thinking of URL rewriting using URLRewriter.Net (http://urlrewriter.net/), or similar, mapping the incoming address to a client id and applying the theme accordingly. So, a url rewrite rule may be something like <rewrite url="http//abc.com/(.+)" to="~/$1?id=1" /> <rewrite url="http//xyz.com/(.+)" to="~/$1?id=2" /> I could then read the id, map it to the client, and with a bit of jiggery-pokery, apply the correct theme. I was wondering if: this is the right approach ? I've overlooked something ? there is a better way to do this ? Any suggestions would be appreciated.

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• Using ControllerClassNameHandlerMapping with @Controller and extending AbstractController

  - by whiskerz

  Hey there, actually I thought I was trying something really simple. ControllerClassNameHandlerMapping sounded great to produce a small spring webapp using a very lean configuration. Just annotate the Controller with @Controller, have it extend AbstractController and the configuration shouldn't need more than this <context:component-scan base-package="test.mypackage.controller" /> <bean id="urlMapping" class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping" /> to resolve my requests and map them to my controllers. I've mapped the servlet to "*.spring", and calling <approot>/hello.spring All I ever get is an error stating that no mapping was found. If however I extend the MultiActionController, and do something like <approot>/hello/hello.spring it works. Which somehow irritates me, as I would have thought that if that is working, why didn't my first try? Does anyone have any idea? The two controllers I used looked like this @Controller public class HelloController extends AbstractController { @Override protected ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response) throws Exception { ModelAndView modelAndView = new ModelAndView("hello"); modelAndView.addObject("message", "Hello World!"); return modelAndView; } } and @Controller public class HelloController extends MultiActionController { public ModelAndView hello(HttpServletRequest request, HttpServletResponse response) throws Exception { ModelAndView modelAndView = new ModelAndView("hello"); modelAndView.addObject("message", "Hello World!"); return modelAndView; } }

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