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• Failure remediation strategy for File I/O

  - by Brett

  I'm doing buffered IO into a file, both read and write. I'm using fopen(), fseeko(), standard ANSI C file I/O functions. In all cases, I'm writing to a standard local file on a disk. How often do these file I/O operations fail, and what should the strategy be for failures? I'm not exactly looking for stats, but I'm looking for a general purpose statement on how far I should go to handle error conditions. For instance, I think everyone recognizes that malloc() could and probably will fail someday on some user's machine and the developer should check for a NULL being returned, but there is no great remediation strategy since it probably means the system is out of memory. At least, this seems to be the approach taken with malloc() on desktop systems, embedded systems are different. Likewise, is it worth reattempting a file I/O operation, or should I just consider a failure to be basically unrecoverable, etc. I would appreciate some code samples demonstrating proper usage, or a library guide reference that indicates how this is to be handled. Any other data is, of course, welcome.

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• Tools to document/visualize call graph?

  - by Dave Griffiths

  Hi, having recently joined a project with a vast amount of code to get to grips with, I would like to start documenting and visualizing some of the flows through the call graph to give me a better understanding of how everything fits together. This is what I would like to see in my ideal tool: every node is a function/method nodes are connected if one function can call another optional square box in between detailing conditions under which call is made (or a label icon you can hover over like a tooltip) also icon on edge describing parameters hover over node and description is displayed optional icons for node to display pseudo code scenario/domain view - display subset of complete diagram for particular use-case slide view mode - for each frame, the currently executing function is highlighted plenty of options over what to display to reduce on-screen clutter the interactive use of such a tool is key, I'm not looking for a Graphviz type solution because there would be too much clutter. The ability to form a view of a subset of the entire graph would be very handy (maybe with the unimportant clutter greyed out). Don't need automatic generation from source code, happy to enter it manually. Almost like a mind-map. Does that make sense? If you are not aware of such a tool, do you also think it would be useful? (Just in case I decide to go and scratch that itch one day!)

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• Loading an XML configuration file BEFORE the flex application loads

  - by Shahar

  Hi, We are using an XML file as an external configuration file for several parameters in our application (including default values for UI components and properties values of some service layer objects). The idea is to be able to load the XML configuration file before the flex application initializes any of its components. This is crucial because XML loading is processed a-synchronously in flex, which can potentially cause race-conditions in the application. For example: the configuration file holds the endpoint URL of a web service used to obtain data from the server. The URL resides in the XML because we want to allow our users to alter the endpoint URL according to their environment. Now because the endpoint URL is retrieved only after the XML has been completely loaded, some of the application's components might be invoking operations on this web service before it is initialized with the correct endpoint. The trivial solution would have been to suspend the initialization of the application until the complete event is dispatched by the loader. But it appears that this solution is far from being trivial. I haven't found a single solution that allows me to load the XML before any other object in the application. Can anyone advice or comment on this matter? Regards, Shahar

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• Byte-Pairing for data compression

  - by user1669533

  Question about Byte-Pairing for data compression. If byte pairing converts two byte values to a single byte value, splitting the file in half, then taking a gig file and recusing it 16 times shrinks it to 62,500,000. My question is, is byte-pairing really efficient? Is the creation of a 5,000,000 iteration loop, to be conservative, efficient? I would like some feed back on and some incisive opinions please. Dave, what I read was: "The US patent office no longer grants patents on perpetual motion machines, but has recently granted at least two patents on a mathematically impossible process: compression of truly random data." I was not inferring the Patent Office was actually considering what I am inquiring about. I was merely commenting on the notion of a "mathematically impossible process." If someone has, in some way created a method of having a "single" data byte as a placeholder of 8 individual bytes of data, that would be a consideration for a patent. Now, about the mathematically impossibility of an 8 to 1 compression method, it is not so much a mathematically impossibility, but a series of rules and conditions that can be created. As long as there is the rule of 8 or 16 bit representation of storing data on a medium, there are ways to manipulate data that mirrors current methods, or creation by a new way of thinking.

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• Is there a way to stop a UIViewController from being popped from a UINavigationController's stack wh

  - by yabada

  I have a UINavigationController with a root view controller and then I push a UIViewController onto the navigation controller's stack. When the user taps the backBarButtonItem I'd like to be able to have an alert view pop up if there are certain conditions met and cancel the pop of the view controller. For example, the user can make certain selections but some combination of them may be invalid so I want to notify them to make changes. I know that I can prevent the user from making an invalid combination or have an alert view pop up when the invalid combination is selected but I'd rather not do that. The user may be changing selections and may be aware that a certain combination is invalid but I'd rather let them select something that makes the combination invalid then go change something else (and notify them if they haven't made changes before trying to go to the previous screen). For example, if I prevent them from make the invalid combination then they may have to scroll up on a screen, change something, then scroll back down instead of making a selection then scrolling up and changing something. Using viewWillDisappear: doesn't work because, although I can produce an alert view, I cannot figure out a way to prevent the pop from occurring. The alert view pops up but the view controller still pops and they are back to the root view controller (with the alert view displaying). Is there a way to prevent the pop from occurring? If not, is this something worth filing a bug report about or is this unnecessary and/or esoteric?

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• Linq In Clause & Predicate building

  - by Michael G

  I have two tables. Report and ReportData. ReportData has a constraint ReportID. How can I write my linq query to return all Report objects where the predicate conditions are met for ReportData? Something like this in SQL: SELECT * FROM Report as r Where r.ServiceID = 3 and r.ReportID IN (Select ReportID FROM ReportData WHERE JobID LIKE 'Something%') This is how I'm building my predicate: Expression<Func<ReportData, bool>> predicate = PredicateBuilder.True<ReportData>(); predicate = predicate.And(x => x.JobID.StartsWith(QueryConfig.Instance.DataStreamName)); var q = engine.GetReports(predicate, reportsDataContext); reports = q.ToList(); This is my query construction at the moment: public override IQueryable<Report> GetReports(Expression<Func<ReportData, bool>> predicate, LLReportsDataContext reportDC) { if (reportDC == null) throw new ArgumentNullException("reportDC"); var q = reportDC.ReportDatas.Where(predicate).Where(r => r.ServiceID.Equals(1)).Select(r => r.Report); return q; }

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• rails named_scope issue with eager loading

  - by Craig

  Two models (Rails 2.3.8): User; username & disabled properties; User has_one :profile Profile; full_name & hidden properties I am trying to create a named_scope that eliminate the disabled=1 and hidden=1 User-Profiles. Moreover, while the User model is usually used in conjunction with the Profile model, I would like the flexibility to be able specify this using the :include = :profile syntax. I have the following User named_scope: named_scope :visible, { :joins => "INNER JOIN profiles ON users.id=profiles.user_id", :conditions => ["users.disabled = ? AND profiles.hidden = ?", false, false] } This works as expected when just reference the User model: >> User.visible.map(&:username).flatten => ["user a", "user b", "user c", "user d"] However, when I attempt to include the Profile model: User.visible(:include=> :profiles).profile.map(&:full_name).flatten I get an error that reads: NoMethodError: undefined method `profile' for #<User:0x1030bc828> Am I able to cross model-collection boundaries in this manner?

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• Parsing Chunk of Data into Hash of Array With Perl

  - by neversaint

  I have data that looks like this: #info #info2 1:SRX004541 Submitter: UT-MGS, UT-MGS Study: Glossina morsitans transcript sequencing project(SRP000741) Sample: Glossina morsitans(SRS002835) Instrument: Illumina Genome Analyzer Total: 1 run, 8.3M spots, 299.9M bases Run #1: SRR016086, 8330172 spots, 299886192 bases 2:SRX004540 Submitter: UT-MGS Study: Anopheles stephensi transcript sequencing project(SRP000747) Sample: Anopheles stephensi(SRS002864) Instrument: Solexa 1G Genome Analyzer Total: 1 run, 8.4M spots, 401M bases Run #1: SRR017875, 8354743 spots, 401027664 bases 3:SRX002521 Submitter: UT-MGS Study: Massive transcriptional start site mapping of human cells under hypoxic conditions.(SRP000403) Sample: Human DLD-1 tissue culture cell line(SRS001843) Instrument: Solexa 1G Genome Analyzer Total: 6 runs, 27.1M spots, 977M bases Run #1: SRR013356, 4801519 spots, 172854684 bases Run #2: SRR013357, 3603355 spots, 129720780 bases Run #3: SRR013358, 3459692 spots, 124548912 bases Run #4: SRR013360, 5219342 spots, 187896312 bases Run #5: SRR013361, 5140152 spots, 185045472 bases Run #6: SRR013370, 4916054 spots, 176977944 bases What I want to do is to create a hash of array with first line of each chunk as keys and SR## part of lines with "^Run" as its array member: $VAR = { 'SRX004541' => ['SRR016086'], # etc } But why my construct doesn't work. And it must be a better way to do it. use Data::Dumper; my %bighash; my $head = ""; my @temp = (); while ( <> ) { chomp; next if (/^\#/); if ( /^\d{1,2}:(\w+)/ ) { print "$1\n"; $head = $1; } elsif (/^Run \#\d+: (\w+),.*/){ print "\t$1\n"; push @temp, $1; } elsif (/^$/) { push @{$bighash{$head}}, [@temp]; @temp =(); } } print Dumper \%bighash ;

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• R selecting duplicate rows

  - by Matt

  Okay, I'm fairly new to R and I've tried to search the documentation for what I need to do but here is the problem. I have a data.frame called heeds.data in the following form (some columns omitted for simplicity) eval.num, eval.count, ... fitness, fitness.mean, green.h.0, green.v.0, offset.0, green.h.1, green.v.1,...green.h.7, green.v.7, offset.7... And I have selected a row meeting the following criteria: best.fitness <- min(heeds.data$fitness.mean[heeds.data$eval.count = 10]) best.row <- heeds.data[heeds.data$fitness.mean == best.fitness] Now, what I want are all of the other rows with that have columns green.h.0 to offset.7 (a contiguous section of columns) equal to the best.row Basically I'm looking for rows that have some of the conditions the same as the "best" row. I thought I could just do this, heeds.best <- heeds.data$fitness[ heeds.data$green.h.0 == best.row$green.h.0 & ... ] But with 24 columns it seems like a stupid method. Looking for something a bit simpler with less manual typing. Thanks!

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• Saving a form using autocomplete instead of select field

  - by Jason Swett

  I have a form that looks like this: <%= form_for(@appointment) do |f| %> <% if @appointment.errors.any? %> <div id="error_explanation"> <h2><%= pluralize(@appointment.errors.count, "error") %> prohibited this appointment from being saved:</h2> <ul> <% @appointment.errors.full_messages.each do |msg| %> <li><%= msg %></li> <% end %> </ul> </div> <% end %> <%= f.fields_for @client do |client_form| %> <div class="field"> <%= client_form.label :name, "Client Name" %><br /> <%= client_form.text_field :name %> </div> <% end %> As you can see, the field for @client is a text field as opposed to select field. When I try to save my form, I get this error: Client(#23852094658120) expected, got ActiveSupport::HashWithIndifferentAccess(#23852079773520) That's not surprising. It seems to me that it was expecting a select field, which it could translate into a Client object, but instead it just got a string. I know I can do Client.find( :first, :conditions => { :name => params[:name] } ) to find a Client with that name, but how do I tell my form that that's what's going on?

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• Best way to dynamically get column names from oracle tables

  - by MNC

  Hi, We are using an extractor application that will export data from the database to csv files. Based on some condition variable it extracts data from different tables, and for some conditions we have to use UNION ALL as the data has to be extracted from more than one table. So to satisfy the UNION ALL condition we are using nulls to match the number of columns. Right now all the queries in the system are pre-built based on the condition variable. The problem is whenever there is change in the table projection (i.e new column added, existing column modified, column dropped) we have to manually change the code in the application. Can you please give some suggestions how to extract the column names dynamically so that any changes in the table structure do not require change in the code? My concern is the condition that decides which table to query. The variable condition is like if the condition is A, then load from TableX if the condition is B then load from TableA and TableY. We must know from which table we need to get data. Once we know the table it is straightforward to query the column names from the data dictionary. But there is one more condition, which is that some columns need to be excluded, and these columns are different for each table. I am trying to solve the problem only for dynamically generating the list columns. But my manager told me to make solution on the conceptual level rather than just fixing. This is a very big system with providers and consumers constantly loading and consuming data. So he wanted solution that can be general. So what is the best way for storing condition, tablename, excluded columns? One way is storing in database. Are there any other ways? If yes what is the best? As I have to give at least a couple of ideas before finalizing. Thanks,

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• is back_insert_iterator<> safe to be passed by value?

  - by afriza

  I have a code that looks something like: struct Data { int value; }; class A { public: typedef std::deque<boost::shared_ptr<Data> > TList; std::back_insert_iterator<TList> GetInserter() { return std::back_inserter(m_List); } private: TList m_List; }; class AA { boost::scoped_ptr<A> m_a; public: AA() : m_a(new A()) {} std::back_insert_iterator<A::TList> GetDataInserter() { return m_a->GetInserter(); } }; class B { template<class OutIt> CopyInterestingDataTo(OutIt outIt) { // loop and check conditions for interesting data // for every `it` in a Container<Data*> // create a copy and store it for( ... it = ..; .. ; ..) if (...) { *outIt = OutIt::container_type::value_type(new Data(**it)); outIt++; // dummy } } void func() { AA aa; CopyInterestingDataTo(aa.GetInserter()); // aa.m_a->m_List is empty! } }; The problem is that A::m_List is always empty even after CopyInterestingDataTo() is called. However, if I debug and step into CopyInterestingDataTo(), the iterator does store the supposedly inserted data!

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• RewriteCond and RewriteRule newbie

  - by mybrokengnome

  I'm taking over a website for a client that is running on a custom built CMS (that I didn't write). I don't mess with .htaccess files usually because a lot of the hosting I do is on IIS, or I used WordPress as a CMS and don't have to worry about messing with the .htaccess file. Here's the contents of the file: RewriteEngine on RewriteCond %{REQUEST_FILENAME} !-f RewriteRule ^(.*)$ framework.php?%{QUERY_STRING}&resource=$1& [L] I get what it's doing (sending all requests through the framework.php file). The client wants a WordPress blog added to their site. I'm placing it in a /blog/ folder. The problem is that because of the rewrite rules and conditions in the .htaccess file whenever I try to go /blog/ the other CMS freaks out because it doesn't like me trying to go there. My question is how do I write a rule/cond that tells apache to send all requests made to the /blog/ folder to the /blog/ folder, but keep all other requests piped through the framework.php file like it is now? Any help is appreciated, thanks!

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• Performance difference in for loop condition?

  - by CSharperWithJava

  Hello all, I have a simple question that I am posing mostly for my curiousity. What are the differences between these two lines of code? (in C++) for(int i = 0; i < N, N > 0; i++) for(int i = 0; i < N && N > 0; i++) The selection of the conditions is completely arbitrary, I'm just interested in the differences between , and &&. I'm not a beginner to coding by any means, but I've never bothered with the comma operator. Are there performance/behavior differences or is it purely aesthetic? One last note, I know there are bigger performance fish to fry than a conditional operator, but I'm just curious. Indulge me. Edit Thanks for your answers. It turns out the code that prompted this question had misused the comma operator in the way I've described. I wondered what the difference was and why it wasn't a && operator, but it was just written incorrectly. I didn't think anything was wrong with it because it worked just fine. Thanks for straightening me out.

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• SystemStackError in Rails::ActiveSupport::Callbacks

  - by coreyward

  I'm building a Rails app that connects to Dropbox and syncs with a folder to update a personal site. I'm using Rails 3.0.3, Ruby 1.9.2, and the Dropbox gem. Right now I have a DropboxAccounts Controller, and two models: DropboxSession, which wraps calls to the gem with application-specific functionality, and DropboxAccount, which stores the session and settings in the database. After the user authorizes their account with Dropbox they're redirected back over and the DropboxAccount is saved with the authorized session. That all works just fine. My problem is that when I try to call Dropbox::API#create_folder(any path) I end up with a SystemStackError in lib/activesupport/callbacks.rb:421 which refers to the code below. If I remove the call to create the folder, it works. If I call create folder from another request, it works. I doubled the stack size to 16K to no avail. # This is called the first time a callback is called with a particular # key. It creates a new callback method for the key, calculating # which callbacks can be omitted because of per_key conditions. # def __create_keyed_callback(name, kind, object, &blk) #:nodoc: @_keyed_callbacks ||= {} @_keyed_callbacks[name] ||= begin str = send("_#{kind}_callbacks").compile(name, object) class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 def #{name}() #{str} end # THIS IS LINE 421 protected :#{name} RUBY_EVAL true end end I'm not very familiar with Rails yet, and I'm not sure what the intention of the code above is or why it would cause a stack overflow. I'm not using any method_missing/ghost method magic in my code. I suspected it was something with a callback serialize :files but commenting it out did nothing. My DropboxAccount model contains only a call to belongs_to :user, and DropboxSession is just a handful of methods, none of which contain callbacks. Bypassing them and using the Dropbox::Session methods directly doesn't help. I hope someone on StackOverflow can help me with this stack overflow. ;)

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• Unknown and unreproducible crash causes App Store rejection

  - by Daniel Johnson

  After submitting our application several times, we continue to receive the following response: Thank you for submitting My App to the App Store. We've reviewed your application and determined that we cannot post this version of your iPad application to the App Store because My App is crashing on iPad running iPhone OS 3.2 and Mac OS X 10.6.2. My App crashes upon launch. Unfortunately, crash logs have not been generated. However, resigning the same build with the AdHoc entitlements and loading the build onto the device yields no such crash. After a number of attempts, the application simply does not crash as reported by the reviewer. Furthermore, the reviewer does not provide any useful logging that may have been generated by SpringBoard such as an exit status or event if it had worked properly for any other device. There are no calls to explicitly exit or quit the application in the code line and yet the application terminates on startup. What might cause an application to terminate in such a manner? Under what conditions is an application tested that might not be found under a development environment? Could it be a result of a signing issue that the submission validation system is simply unable to catch? Thanks in advance.

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• Testing approach for multi-threaded software

  - by Shane MacLaughlin

  I have a piece of mature geospatial software that has recently had areas rewritten to take better advantage of the multiple processors available in modern PCs. Specifically, display, GUI, spatial searching, and main processing have all been hived off to seperate threads. The software has a pretty sizeable GUI automation suite for functional regression, and another smaller one for performance regression. While all automated tests are passing, I'm not convinced that they provide nearly enough coverage in terms of finding bugs relating race conditions, deadlocks, and other nasties associated with multi-threading. What techniques would you use to see if such bugs exist? What techniques would you advocate for rooting them out, assuming there are some in there to root out? What I'm doing so far is running the GUI functional automation on the app running under a debugger, such that I can break out of deadlocks and catch crashes, and plan to make a bounds checker build and repeat the tests against that version. I've also carried out a static analysis of the source via PC-Lint with the hope of locating potential dead locks, but not had any worthwhile results. The application is C++, MFC, mulitple document/view, with a number of threads per doc. The locking mechanism I'm using is based on an object that includes a pointer to a CMutex, which is locked in the ctor and freed in the dtor. I use local variables of this object to lock various bits of code as required, and my mutex has a time out that fires my a warning if the timeout is reached. I avoid locking where possible, using resource copies where possible instead. What other tests would you carry out?

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• If a nonblocking recv with MSG_PEEK succeeds, will a subsequent recv without MSG_PEEK also succeed?

  - by Michael Wolf

  Here's a simplified version of some code I'm working on: void stuff(int fd) { int ret1, ret2; char buffer[32]; ret1 = recv(fd, buffer, 32, MSG_PEEK | MSG_DONTWAIT); /* Error handling -- and EAGAIN handling -- would go here. Bail if necessary. Otherwise, keep going. */ /* Can this call to recv fail, setting errno to EAGAIN? */ ret2 = recv(fd, buffer, ret1, 0); } If we assume that the first call to recv succeeds, returning a value between 1 and 32, is it safe to assume that the second call will also succeed? Can ret2 ever be less than ret1? In which cases? (For clarity's sake, assume that there are no other error conditions during the second call to recv: that no signal is delivered, that it won't set ENOMEM, etc. Also assume that no other threads will look at fd. I'm on Linux, but MSG_DONTWAIT is, I believe, the only Linux-specific thing here. Assume that the right fnctl was set previously on other platforms.)

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• Access 2007 not allowing user to delete record in subform

  - by Todd McDermid

  Good day... The root of my issue is that there's no context menu allowing the user to delete a row from a form. The "delete" button on the ribbon is also disabled. In Access 2003, apparently this function was available, but since our recent "upgrade" to 2007 (file is still in MDB format) it's no longer there. Please keep in mind I'm not an Access dev, nor did I create this app - I inherited support for it. ;) Now for the details, and what I've tried. The form in question is a subform on a larger form. I've tried turning "AllowDeletes" on on both forms. I've checked the toolbar and ribbon properties on the forms to see if they loaded some custom stuff, but no. I've tried changing the "record locks" to "on edit", no joy. I examined the query to see if it was "too complicated" to permit a delete - as far as I can tell, it's a very simple two (linked) table join. Compared to another form in this app that does permit row deletes, it has a much more complicated (multi-join, built on queries) query. Is there a resource that would describe the required conditions for allowing deletes? Thanks in advance...

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• Lost Array After Validation Error

  - by Georges Kmeid

  I'm working on a CakePHP project and I have User, Post and Location models among others. User hasMany Location and Post belongsTo User so Location is not directly related to Post. This is my code in the Post controller: public function add() { if ($this->request->is('get')) { $this->loadModel('Location'); $this->set('locations', $this->Location->find('all', array('conditions' => array('user_id' => $this->Auth->user('id'))))); } ... } And this is my code in the posts/add view: <?php $i = 0; $j = 0; foreach ($locations as $location): $location_names[$i] = $location['Location']['name']; $i++; endforeach; echo "<select name=\"location\" onchange=\"select(this.value)\">"; echo "<option value=\"\">Select a saved location</option>"; foreach ($locations as $location): echo "<option value=\"" . $location['Location']['latitude'] . "," . $location['Location']['longitude'] . "\">" . $location_names[$j] . "</option>"; $j++; endforeach; ?> </select> If I enter a wrong value in one of the post inputs that has a validation rule in Post model, it redirects to the current add view, shows what is the validation error, but then the $locations array passed from controller to view disappears and can't use it in view and I get this error: Notice (8): Undefined variable: locations [APP\View\Posts\add.ctp, line 68]

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• formatting an array of mobile numbers

  - by Kyle Hudson

  Hi, I am creating a SMS app the following code is supposed to: check if the mobile/cell number is 11 characters long. check if the number starts with 07. If neither of these conditions are met, it should remove the number from the array. So the following numbers would be valid: 07123456789,07123456790,07123456791,07123456792,07123456793,07123456794 However the following wouldn't (and need to be removed): 0801458,07855488,6695522214124514 $param["number"] = "07123456789,07123456790,07123456791,07123456792,07123456793,07123456794,0801458,07855488,6695522214124514"; $number = explode(',', $param["number"]); foreach($number as $num){ if (!substr_compare($num, "07", 0, 3, false)) { unset($num); } elseif (substr_compare($num, "07", 0, 3, true)) { if(strlen($num) == 11) { $li .= "447" . substr($num, 2) . ','; } } } $il .= substr($li, 0, strlen($li)-1); echo $il; // $request = substr($request, 0, strlen($request)-1); // return $n; } I also need to remove the final comma from the result. Any help will be appriciated. Thanks, Kyle

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• Group and sort blog posts by date in Rails

  - by Senthil

  I've searched all over web and have not found the answer. I'm trying to have a very standard archive option for my blog based on date. A request to url blog.com/archive/2009 shows all posts in 2009, blog.com/archive/2009/11 shows all posts in November 2009 etc. I found two different of code but not very helpful to me. def display_by_date year = params[:year] month = params[:month] day = params[:day] day = '0'+day if day && day.size == 1 @day = day if (year && month && day) render(:template => "blog/#{year}/#{month}/#{date}") elsif year render(:template => "blog/#{year}/list") end end def archive year = params[:year] month = params[:month] day = params[:day] day = '0'+day if day && day.size == 1 if (year && month && day) @posts_by_month = Blog.find(:all, :conditions => ["year is?", year]) else @posts_by_month = Blog.find(:all).group_by { |post| post.created_at.strftime("%B") } end end Any help is appreciated.

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• What is happening in Crockford's object creation technique?

  - by Chris Noe

  There are only 3 lines of code, and yet I'm having trouble fully grasping this: Object.create = function (o) { function F() {} F.prototype = o; return new F(); }; newObject = Object.create(oldObject); (from Prototypal Inheritance) 1) Object.create() starts out by creating an empty function called F. I'm thinking that a function is a kind of object. Where is this F object being stored? Globally I guess. 2) Next our oldObject, passed in as o, becomes the prototype of function F. Function (i.e., object) F now "inherits" from our oldObject, in the sense that name resolution will route through it. Good, but I'm curious what the default prototype is for an object, Object? Is that also true for a function-object? 3) Finally, F is instantiated and returned, becoming our newObject. Is the "new" operation strictly necessary here? Doesn't F already provide what we need, or is there a critical difference between function-objects and non-function-objects? Clearly it won't be possible to have a constructor function using this technique. What happens the next time Object.create() is called? Is global function F overwritten? Surely it is not reused, because that would alter previously configured objects. And what happens if multiple threads call Object.create(), is there any sort of synchronization to prevent race conditions on F?

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• Dangers when deploying Flash/Flex UI test automation hooks to production?

  - by Merlyn Morgan-Graham

  I am interested in doing automated testing against a Flex based UI. I have found out that my best options for UI automation (due to being C# controllable, good licensing conditions, etc) all seem to require that I compile test hooks into my application. Because of this, I am thinking of recommending that these hooks be compiled into our build. I have found a few places on the net that recommend not deploying bits with this instrumentation enabled, and I'd like to know why. Is it a performance drain, or a security risk? If it is a security risk, can you explain how the attack surface is increased? I am not a Flash or Flex developer, though I have some experience with threat modeling. For reference, here's the tools I'm specifically considering: QTP Selenium-Flex API I am having problems finding all the warnings/suggestions I found last night, but here's an example that I can find: http://www.riatest.com/products/getting-started.html Warning! Automation enabled applications expose all properties of all GUI components. This makes them vulnerable to malicious use. Never make automation enabled application publicly available. Always restrict access to such applications and to RIATest Loader to trusted users only. Related question (how to do conditional compilation to insert/remove those hooks): Conditionally including Flex libraries (SWCs) in mxmlc/compc ant tasks

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• Cakephp Search Plugin: DateTime Range

  - by Chris

  I am trying to search a model by dates using the CakePHP Search plugin The idea is: The user enters a date of a flight and the engine returns all flights within +- one day of that. My form: <?php echo $form->create('Flight', array( 'url' => array_merge(array('action' => 'find'), $this->params['pass']) )); echo $form->input('departure', array('div' => false, 'dateFormat' => 'DMY','timeFormat' => 'NONE')); echo $form->submit(__('Search', true), array('div' => false)); echo $form->end(); ?> My flight model: public $filterArgs = array( array('name' => 'departure', 'type' => 'expression', 'method' => 'makeRangeCondition', 'field' => 'ABS((TO_Days(Flight.departure))-( TO_Days(?))) < 2') ); The controller: public $presetVars = array( array('field' => 'departure', 'type' => 'expression') ); public function find() { $this->Prg->commonProcess(); $this->paginate['conditions'] = $this->Flight->parseCriteria($this->passedArgs); $this->set('flights', $this->paginate()); } When I try to search, the values for departure are packed in an array; Array ([departure] => Array ) And the filterArgs(...) function doesn't seem to understand this. What is the correct way to do this?

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