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• Debugging scripts loaded with GroovyShell (in eclipse)

  - by MSh

  I am working with eclipse and groovy plug in. I am building a test harness to debug and test groovy scripts. The scripts are really simple but long, most of them just if/else/return. I figured out that I can call them using GroovyShell and Bindings to pass in the values. The problem is that, while I can call the script and get the results just fine, I CAN NOT step in there with the debugger. Breakpoints in those scripts are not active. Is there a way to debug the scripts? Maybe I should use something other than GroovyShell? I really don't want to modify the scripts by wrapping them into functions, and then calling those functions from my test classes. That's how I am using Binding and GroovyShell: def binding = new Binding(); binding.lineList = [list1]; binding.count = 5; def shell = new GroovyShell(binding); def result = shell.evaluate(new File("src/Rules/checkLimit.groovy"));

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• C++ union data-structure, easy acccess of bits within a DWORD

  - by TK

  Im running through a set of DirectX tutorials online and I have the following structure: struct CUSTOMVERTEX { FLOAT x, y, z, rhw; // from the D3DFVF_XYZRHW flag DWORD color; // from the D3DFVF_DIFFUSE flag } My basic understanding of directX leads me to thing tha color is made up of 8-bit alpha, red, green and blue channels. I am attempting to get east access to these channels. Rather than write the following code numerous times (within the CUSTOMVERTEX structure): public: int red() { return (color & 0x00FF0000) >> 16; } I could write a more elegant somution with a combination of a union and a structure e.g. struct CUSTOMVERTEX { FLOAT x, y, z, rhw; // from the D3DFVF_XYZRHW flag #pragma pack(2) union { DWORD color; // from the D3DFVF_DIFFUSE flag struct { char a; char r; char g; char b; }; }; } However this does not appear to function as expected, the values in r, g, & b almost appear the reverse of whats in color e.g. if color is 0x12345678 a = 0x78, r = 0x56. Is this an endieness issue? Also what other problems could I be expecting from this solution? e.g. overflow from the color members? I guess what Im asking is ... is there a better way to do this?!

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• Which options do I have for Java process communication?

  - by Dmitriy Matveev

  We have a place in a code of such form: void processParam(Object param) { wrapperForComplexNativeObject result = jniCallWhichMayCrash(param); processResult(result); } processParam - method which is called with many different arguments. jniCallWhichMayCrash - a native method which is intended to do some complex processing of it's parameter and to create some complex object. It can crash in some cases. wrapperForComplexNativeObject - wrapper type generated by SWIG processResult - a method written in pure Java which processes it's parameter by creation of several kinds (by the kinds I'm not meaning classes, maybe some like hierarchies) of objects: 1 - Some non-unique objects which are referencing each other (from the same hierarchy), these objects can have duplicates created from the invocations of processParam() method with different parameter values. Since it's costly to keep all the duplicates it's necessary to cache them. 2 - Some unique objects which are referencing each other (from the same hierarchy) and some of the objects of 1st kind. After processParam is executed for each of the arguments from some set the data created in processResult will be processed together. The problem is in fact that jniCallWhichMayCrash method may crash the entire JVM and this will be very bad. The reason of crash may be such that it can happen for one argument value and not for the other. We've decided that it's better to ignore crashes inside of JVM and just skip some chunks of data when such crashes occur. In order to do this we should run processParam function inside of separate process and pass the result somehow (HOW? HOW?! This is a question) to the main process and in case of any crashes we will only lose some part of data (It's ok) without lose of everything else. So for now the main problem is implementation of transport between different processes. Which options do I have? I can think about serialization and transmitting of binary data by the streams, but serialization may be not very fast due to object complexity. Maybe I have some other options of implementing this?

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• Get parent attribute within new child form?

  - by dannymcc

  I have a simple Rails 3 application and I am trying to create a new record that belongs to it's owner. It's working by passing the id to a hidden field in the new form of the child record. This works well and once the new child form submitted it correctly gets associated in the child/parent relationship. What I am trying to do, is lookup values form the parent within the new child form. The problem is that the child relationship is not yet created. Is there anyway I can use a .where lookup in the view? Or, is there a better way of doing this? At the moment I am passing the animal_id though to the new Claim form and it's inserted into a hidden field labelled animal_id. What I am trying to do: <%= @animal.where(:animal_id => params[:animal_id]).id %> The above would ideally get the animal ID from the soon-to-be-associated animal. Is there any sort of before_filter or anything that could take the passed params from the URL and temporarily create the relationship just for the new form view and then permanently create the relationship once the form is submitted? I've tried adding the following to my Claims controller and then called @animal.AnimalName in the view but I get NoMethodError: before_filter :find_animal protected def find_animal if params[:animal_id] Animal.find(params[:animal_id]) end end The URL of the new claim is correctly showing the animal ID so I'm not sure why it's not finding it: http://localhost:3000/claims/new?animal_id=1 The model relations are as follows: animal has_many claims animal has_one exclusion claim has_one animal exception has_one animal

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• Copy a LinkedList that has a Random Pointer in it

  - by Bragaadeesh

  Hi, First of all this is not a homework, this is an interview question that I got from a company I attended today. You have a singly linked list with the Node structure as the following class Node{ int data; Node next; Node random; } You have a typical singly linked list of length n. The random pointer in each node in the linkedlist randomly points to some Node within the linked list. The Question is to create a copy of the linked list efficiently into a different LinkedList. I said that I will first calculate the Random pointer's position in the linked list and store it in an array. Then create a new linked list normally. Then iterate through the linked list by setting the random pointer where they belong by reading the values stored from the array. I know its a very brute force technique and the interviewer asked me to come up with a better solution but I couldnt. Please can someone answer this? I can explain if the question is not clear.

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• visual analysis of web pages in ruby

  - by Clint Miller

  I'm looking to write some code that does visual analysis of web pages, preferably using Ruby. My code will need to be able to determine the top, left, width, height, background color, color, and font size for all the elements in the DOM. Of course, these values can only be calculated once all CSS is applied. So, I don't think that Nokogiri is up for the job. Ultimately, I'm trying to use this data in a VIPS-like (Vision-Based Page Segmentation) algorithm in an attempt to find the main content in downloaded news articles. I've considered using Watir to drive Chrome or Firefox and then extract the data. The problem is that browsers can't be run headless through Watir (I think). Ultimately, this code will be running on an array of Linux servers in a data center. So, the code won't have easy access to an X Server for displaying the browser. I suppose one solution is to use Watir and run a headless X Server on the Linux servers. That's a bit of a pain, but it looks like my best option right now. Does anyone have any better ideas?

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• How should I lock the table in this VB6 / Access application?

  - by Brian Hooper

  I'm working on a VB6 application using an Access database. The application writes messages to a log table from time to time. Several instances of the application may be running simultaneously and to distinguish them they each have their own run number. The run number is deduced from the log table thus... Set record_set = New ADODB.Recordset query_string = "SELECT MAX(RUN_NUMBER) + 1 AS NEW_RUN_NUMBER FROM ERROR_LOG" record_set.CursorLocation = adUseClient record_set.Open query_string, database_connection, adOpenStatic, , adCmdText record_set.MoveLast If IsNull(record_set.Fields("NEW_RUN_NUMBER")) Then run_number = 0 Else run_number = record_set.Fields("NEW_RUN_NUMBER") End If command_string = "INSERT INTO ERROR_LOG (RUN_NUMBER, SEVERITY, MESSAGE) " & _ " VALUES (" & Str$(run_number) & ", " & _ " " & Str$(SEVERITY_INFORMATION) & ", " & _ " 'Run Started'); " database_connection.Execute command_string Obviously there is a small gap between the calculation of the run number and the appearance of the new row in the database, and to prevent another instance getting access between the two operations I'd like to lock the table; something along the lines of SET TRANSACTION READ WRITE RESERVING ERROR_LOG FOR PROTECTED WRITE; How should I go about doing this? Would locking the recordset do any good (the row in the record set doesn't match any particular row in the database)?

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• jQuery + form + textinput > Is it possible to display one value in a textinput and submit another?

  - by Ivan Kruchkoff

  I'm working on an application where dates are passed as yyyy-mm-dd but displayed to the client as mm-dd-yyyy (US based client). I'm using a jQuery datepicker for selecting from/to dates in a report and would like to show the dates to the client as mm-dd-yyyy but when the form is submitted, submit as yyyy-mm-dd. Is it possible to display one value in a textinput textbox and have another submitted without needing to hook into onSubmit? I've come up with the following alternatives: Hide the text input for the from and to fields, create dummy fields and make use of the following jQuery date picker functions: altField and altFormat to display the value to the client in their preferred way and deal only with the submitted values which are set through the alt functions. Have an onSubmit javascript call to change the dates from mm-dd-yyyy to dd-mm-yyyy and also change the value=" to change the date to the client's preferred format. Rewrite the app to handle all dates in mm-dd-yyyy and hope the client never has non-US customers that would like their dates in a specific format. Change all dates to dd-Mon-YYYY e.g. 26-May-2010 as all of our client's customers are guaranteed to be English only.

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• java /TableModel of Objects/Update Object"

  - by Tomás Ó Briain

  I've a collection of Stock objects that I'm updating about 10/15 variables for in real-time. I'm accessing each Stock by its ID in the collection. I'm also trying to display this in a JTable and have implemented an AbstractTablemodel. It's not working too well. I've a RowMap that I add each ID to as Stocks are added to the TableModel. To update the prices and variables of all the stocks in the TableModel, I want to send a Stock object to an updateModel(Stock s) method. I can find the relevant row by searching the map, but how do I handle this nicely, so I don't have to start iterating through table columns and comparing the values of the cells to the variables of the object to see whether there are any differences?? Basically, i want to send a Stock object to the TableModel and update cells if there are changes and do nothing if there aren't. Any ideas about how to implement a TableModel that might do this? Any pointeres at all would be appreciated. Thanks.

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• How do I create a polymorphic model with a collection_select?

  - by muxe

  This are my models: class Speaker < ActiveRecord::Base belongs_to :session, :foreign_key => :session_id, :class_name => :Session belongs_to :speakable, :polymorphic => true end class Session < ActiveRecord::Base has_many :speakers accepts_nested_attributes_for :speakers end class Person < ActiveRecord::Base has_many :speakers, :as => :speakable end class Company < ActiveRecord::Base has_many :speakers, :as => :speakable end What I want to do now is something like this: app/views/sessions/edit.html.erb <% f.fields_for :speakers do |sf| %> <p> <%= sf.label :speaker %><br /> <%= sf.collection_select :speakable, Company.all + Person.all, :id, :full_name %> </p> <% end %> But it is not working because of the polymorphic assignment. How do I approach this problem? EDIT: The Error is: undefined method `base_class' for String:Class with params being: "speaker"=>{"speakable"=>"1063885469", "session_id"=>"1007692731"} The value passed to speakable is the id of the Speaker/Company. Yes, this is the value I specified the collection_select to return, but how can I manage to supply both values (speakable_id and speakable_type) ?

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• Ruby 1.9: turn these 4 arrays into hash of key/value pairs

  - by randombits

  I have four arrays that are coming in from the client. Let's say that there is an array of names, birth dates, favorite color and location. The idea is I want a hash later where each name will have a hash with respective attributes: Example date coming from the client: [name0, name1, name2, name3] [loc0, loc1] [favcololor0, favcolor1] [bd0, bd1, bd2, bd3, bd4, bd5] Output I'd like to achieve: name0 => { location => loc0, favcolor => favcolor0, bd => bd0 } name1 => { location => loc1, favcolor => favcolor1, bd => bd1 } name2 => { location => nil, favcolor => nil, bd => bd2 } name3 => { location => nil, favcolor => nil, bd => bd3 } I want to have an array at the end of the day where I can iterate and work on each particular person hash. There need not be an equivalent number of values in each array. Meaning, names are required.. and I might receive 5 of them, but I only might receive 3 birth dates, 2 favorite colors and 1 location. Every missing value will result in a nil. How does one make that kind of data structure with Ruby 1.9?

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• When do Symfony's user attributes get written to session?

  - by Rob Wilkerson

  I have a Symfony app that populates the "widgets" of a portal application and I'm noticing something (that seems) odd. The portal app has iframes that make calls to the Symfony app. On each of those calls, a random user key is passed on the query string. The Symfony app stores that key its session using myUser->setAttribute(). If the incoming value is different from what it has in session, it overwrites the session value. In pseudo-code (and applying a synchronous nature for clarity even though it may not exist): # Widget request arrives with ?foo=bar if the user attribute 'foo' does not equal 'bar' overwrite the user attribute 'foo' with 'bar' end What I'm noticing is that, on a portal page with multiple widgets (read: multiple requests coming in more or less simultaneously) where the value needs to be overwritten, each request is trying to overwrite. Is this a timing problem? When I look at the log prints, I'd expect the first request that arrives to overwrite and subsequent requests to see that the user attribute they received matches what was just put into cache by the initial request. In this scenario, it could be that subsequent requests begin (and are checked) even before the first one--the one that should overwrite the cached value--has completely finished. Are session values not really available to subsequent requests until one request has completed entirely or could there be something else that I'm missing? Thanks.

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• Inline form editing on client side

  - by bykasif

  I see some web sites use dynamic forms(I am not sure about how to call them!) to edit a group of data. For example: there is a group of data such as name, last name, city, country.etc. when user clicks on EDIT button, instead of doing postback, a form, consisisting of 2 textboxes + 2 comboboxes, dynamically opens to edit,And then when you click on Save button, edit form disappears, and all data updates.. Now, I know what happens over here is using Ajax for server calls and some javascript for dom manipulation.. I even found some jquery plugins for textbox editing.. However, I could not found anything for full implementation of form fields. Therefore I have implemented it on asp.net by jquery ajax calls and dom manipulation manually. here is my process: 1) when Edit button clicked: Make a ajax call to server to retrieve necessary formedit.aspx 2) it returns editable form fields with values assigned. 3) when Save button clicked: make ajax call to server to retrieve formupdateprocess.aspx page. it basically do the database updates and then return necessary DOM snipplet (...) to insert current page.. well it works but MY PROBLEM, is performance.. Result seems slower than samples I see in other sites.:(( IS there anything that I dont know? a better way to implement this??

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• How to render all records from a nested set into a real html tree

  - by Christoph Schiessl

  I'm using the awesome_nested_set plugin in my Rails project. I have two models that look like this (simplified): class Customer < ActiveRecord::Base has_many :categories end class Category < ActiveRecord::Base belongs_to :customer # Columns in the categories table: lft, rgt and parent_id acts_as_nested_set :scope => :customer_id validates_presence_of :name # Further validations... end The tree in the database is constructed as expected. All the values of parent_id, lft and rgt are correct. The tree has multiple root nodes (which is of course allowed in awesome_nested_set). Now, I want to render all categories of a given customer in a correctly sorted tree like structure: for example nested <ul> tags. This wouldn't be too difficult but I need it to be efficient (the less sql queries the better). Update: Figured out that it is possible to calculate the number of children for any given Node in the tree without further SQL queries: number_of_children = (node.rgt - node.lft - 1)/2. This doesn't solve the problem but it may prove to be helpful.

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• Implementation help... Subclass NSManagedObject?

  - by Canada Dev

  I'm working on an app where I have some products that I download in a list. The downloaded products are displayed in a table and each will is showing a detail view with more information. These same products can be saved as a favorite, and for this I am using Core Data. I'd like to be able to re-use a bunch of views for displaying the products, which means the stores object and the downloaded object would have to be the same kind. Now, how would I go about best implementing the objects? Can I make a class such as this: FavoriteProduct : NSManageObject // implementation and then subclass Product : FavoriteProduct // implementation ? The CD class just doesn't give me everything. What would be the best way to merge these two object classes so I have as little work ahead of me in terms of implementing the different views for each object? Basically, I just want to be able to call the same methods, etc. on the Product objects as I would on the ones that are FavoriteProduct objects, and re-use views for both kinds. There's only a bit of difference between the two (one is of course stored as a favorite and has some extra values such as notes, tags, while the Product one doesn't). Thanks in advance

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• WPF Binding Path=/ not working?

  - by Mark

  I've set up my DataContext like this: <Window.DataContext> <c:DownloadManager /> </Window.DataContext> Where DownloadManager is Enumerable<DownloadItem>. Then I set my DataGrid like this: <DataGrid Name="dataGrid1" ItemsSource="{Binding Path=/}" ... So that it should list all the DownloadItems, right? So I should be able to set my columns like: <DataGridTextColumn Binding="{Binding Path=Uri, Mode=OneWay}" Where Uri is a property of the DownloadItem. But it doesn't seem to like this. In the visual property editor, it doesn't recognize Uri is a valid property, so I'm guessing I'm doing something wrong. It was working before, when I had the data grid binding to Values, but then I took that enumerable out of the DownloadManager and made itself enumerable. How do I fix this? PS: By "doesn't work" I mean it doesn't list any items. I've added some to the constructor of the DM, so it shouldn't be empty.

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• Prototype: Form.serialize missing some inputs (due to table?)

  - by Chris

  I'm using JavaScript Prototype (through Ruby on Rails) to handle some Ajax calls; but in one particular case I'm missing a field from the form. I have a layout like this: +---------+---------+ | Thing 1 | Thing 2 | +---------+---------+-----------+ | o Opt 1 | o Opt 1 | <Confirm> | | o Opt 2 | o Opt 2 | | +---------+---------+-----------+ Opt 1 and 2 are Radio buttons, Confirm is a button. The entire table is wrapped in a form, with code like: <form action="javascript:void(0)"> <input type="hidden" name="context" value="foo" /> <input type="hidden" name="subcontext" value="bar" /> <table> <tr><td>Thing 1</td><td>Thing2</td></tr> <tr><td> <input type="radio" name="choice" value="1.1" />Opt 1<br /> <input type="radio" name="choice" value="1.2" />Opt 2<br /> </td><td> <input type="radio" name="choice" value="2.1" />Opt 1<br /> <input type="radio" name="choice" value="2.2" />Opt 2<br /> </td><td> <input name="choice_btn" type="button" value="Confirm" onclick="new AJAX.Updater('my_form', '/process_form', {asynchronous:true, evalScripts:true, parameters:Form.serialize(this.form)}); return false;" /> </td></tr> </table> </form> But I can see that the POST generated by clicking the Confirm button contains the foo and bar values for the hidden fields, but not the choice of the radio buttons. Is this because I've got a table inside my form? How can I get around this?

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• Pointer inside a struct / thread

  - by bruno

  Hi! I have this warning "warning: assignment from incompatible pointer type " in this line: data1->transformed_block[l] = &transformed_block[l]; - void print_message_function ( void *ptr ) { dt *data; data = (dt *) ptr; printf("Dentro da thread Numero0: %ld\n", data->L_norm_NewBlock); pthread_exit(0); } typedef struct data_thread { long L_norm_NewBlock; int Bsize_X; int Bsize_Y; int *transformed_block[MAX_LEVEL]; long L_norm_OrigBlock; } dt; void function() { int *transformed_block[MAX_LEVEL]; pthread_t thread1; dt *data1; pthread_attr_t attr; pthread_attr_init(&attr); //Fills structure data1 = (dt *) malloc(sizeof(dt)); data1->transformed_block[l] = &transformed_block[l]; data1->L_norm_NewBlock=0; data1->Bsize_Y = Bsize_Y; data1->Bsize_X = Bsize_X; pthread_create(&thread1, &attr, (void *) &print_message_function, (void *) &data1); } I want to get rid of that warning, and the values i get inside the thread are wrong. For example data1-L_norm_NewBlock=0; in the thread guives me a differente value (not 0 like it should be).

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• connecting to mysql from excel: ODBC driver does not support the requested properties.

  - by every_answer_gets_a_point

  i am trying to add data to mysql from excel. i am getting the above error on this line: rs.Open strSQL, oConn, adOpenDynamic, adLockOptimistic here is my code: Dim oConn As ADODB.Connection Private Sub ConnectDB() Set oConn = New ADODB.Connection oConn.Open "DRIVER={MySQL ODBC 5.1 Driver};" & _ "SERVER=localhost;" & _ "DATABASE=employees;" & _ "USER=root;" & _ "PASSWORD=some_pass;" & _ "Option=3" End Sub Function esc(txt As String) esc = Trim(Replace(txt, "'", "\'")) End Function Private Sub InsertData() Dim rs As ADODB.Recordset Set rs = New ADODB.Recordset ConnectDB With wsBooks For rowCursor = 2 To 11 strSQL = "INSERT INTO tutorial (author, title, price) " & _ "VALUES ('" & esc(.Cells(rowCursor, 1)) & "', " & _ "'" & esc(.Cells(rowCursor, 2)) & "', " & _ esc(.Cells(rowCursor, 3)) & ")" rs.Open strSQL, oConn, adOpenDynamic, adLockOptimistic Next End With End Sub whats wrong with rs.Open strSQL, oConn, adOpenDynamic, adLockOptimistic ? why am i getting the odbc error?

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• Insert only adds upto 1000 records and ignoresall records after that.

  - by user560559

  i have a large database where the client stores personal messages and fire email notifications [if allowed by the users]. certain users have the option of sending messages to their entire network of friends. some users have over 5000 friends in their network so if they select the whole network they'll be sending messages to over 5000 friends and system will store all the messages into a table. the problem is this that it does not insert more than 1000 records and ignores all inserts after the first 1000. i have increased the packet size, bulk_insert_buffer_size but still no luck. since the system stores some of the info in another table for reports, every insert returns its new message id. due to this i can not use the "insert into table (column1,column2) values (value1,value2) , (value1,value2)....etc." table engine is innodb, mysql version is 5.1.3 and is hosted on amazon web services. all i want is to fix this issue of inserting more than 1000 records at a time. as mentioned earlier, it works fine but only up to 1000 records and simply ignores all the records after that. i'm using php foreach(){} to insert message for each friend and if email is available, send notification to the user. this foreach(){} also inserts the same record in another table [with only 3 columns] for generating reports.

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• java hashmap array to double array

  - by Tweety

  Hi, I declared LinkedHashMap<String, float[]> and now I want to convert float[] values into double[][]. I am using following code. LinkedHashMap<String, float[]> fData; double data[][] = null; Iterator<String> iter = fData.keySet().iterator(); int i = 0; while (iter.hasNext()) { faName = iter.next(); tValue = fData.get(faName); //data = new double[fData.size()][tValue.length]; for (int j = 0; j < tValue.length; j++) { data[i][j] = tValue[j]; } i++; } When I try to print data System.out.println(Arrays.deepToString(data)); it doesn't show the data :( I tried to debug my code and i figured out that I have to initialize data outside the while loop but then I don't know the array dimensions :( How to solve it? Thanks

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• How to give new life into a five years old, simple but reliable PHP form?

  - by Sam

  Hi all. I have a script in php 5.2. I want to use a simple form. I found something a programmer made for me about 5 years ago. When I use it, PHP outputs an error now unless I set register_long_arrays = On, then it works fine. On the PHP website, however, it says: Warning This feature has been DEPRECATED as of PHP 5.3.0. Relying on this feature is highly discouraged. It's recommended to turn them off, for performance reasons. Instead, use the superglobal arrays, like $_GET. Should I listen to PHP's warning, or just enable the option and keep using my old form happily? If the former, then how/where do I change this simple form, so it does not rely on the deprecated setting? Your answer is much appreciated. form.htm <html><body> <form method="POST" action="form_sent.php"> ... </form> </body></html> form_sent.php <html><body> <?php $email = $HTTP_POST_VARS[email]; $mailto = "[email protected]"; $mailsubj = "A Form was Sent from Website!"; $mailhead = "From: $email\n"; reset ($HTTP_POST_VARS); $mailbody = "Values submitted from web site form:\n"; while (list($key, $val) = each ($HTTP_POST_VARS)){$mailbody .= "$key : $val\n";} if (!eregi("\n",$HTTP_POST_VARS[email])) { mail($mailto, $mailsubj, $mailbody, $mailhead); } ?> <b>Form Sent. Thank you.</b> </body></html>

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• C++ Virtual Methods for Class-Specific Attributes or External Structure

  - by acanaday

  I have a set of classes which are all derived from a common base class. I want to use these classes polymorphically. The interface defines a set of getter methods whose return values are constant across a given derived class, but vary from one derived class to another. e.g.: enum AVal { A_VAL_ONE, A_VAL_TWO, A_VAL_THREE }; enum BVal { B_VAL_ONE, B_VAL_TWO, B_VAL_THREE }; class Base { //... virtual AVal getAVal() const = 0; virtual BVal getBVal() const = 0; //... }; class One : public Base { //... AVal getAVal() const { return A_VAL_ONE }; BVal getBVal() const { return B_VAL_ONE }; //... }; class Two : public Base { //... AVal getAVal() const { return A_VAL_TWO }; BVal getBVal() const { return B_VAL_TWO }; //... }; etc. Is this a common way of doing things? If performance is an important consideration, would I be better off pulling the attributes out into an external structure, e.g.: struct Vals { AVal a_val; VBal b_val; }; storing a Vals* in each instance, and rewriting Base as follows? class Base { //... public: AVal getAVal() const { return _vals->a_val; }; BVal getBVal() const { return _vals->b_val; }; //... private: Vals* _vals; }; Is the extra dereference essentially the same as the vtable lookup? What is the established idiom for this type of situation? Are both of these solutions dumb? Any insights are greatly appreciated

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• Rails: creating a model in the new action

  - by Joseph Silvashy

  I have an interesting situation, well it's probably not that unique at all, but I'm not totally sure how to tackle it. I have a model, in this case a recipe and the user navigates to the new path /recipes/new however the situation is that I need to be able to have the user upload images and make associations to that model in the new action, but the model doesn't have an ID yet. So I assume I need to rethink my controller, but I don't want to have redirects and whatnot, how can accomplish this? Here is the basic controller, barebones obviously: ... def new # I should be creating the model first, so it has an ID @recipe = Recipe.new end def create @recipe = Recipe.new(params[:recipe]) if @recipe.save redirect_to @recipe else render 'new' end end ... update Perhaps I can have a column thats like state which could have values like new/incomplete/complete or what-have-you. I'm mostly trying to figure out what would also be most efficient for the DB. It would be nice if I could still have a url that said '/new', instead of it be the edit path with the id, for usability sake, but I'm not sure this can be simply accomplished in the new action of my controller. Thoughts?

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• vectorize is indeterminate

  - by telliott99

  I'm trying to vectorize a simple function in numpy and getting inconsistent behavior. I expect my code to return 0 for values < 0.5 and the unchanged value otherwise. Strangely, different runs of the script from the command line yield varying results: sometimes it works correctly, and sometimes I get all 0's. It doesn't matter which of the three lines I use for the case when d <= T. It does seem to be correlated with whether the first value to be returned is 0. Any ideas? Thanks. import numpy as np def my_func(d, T=0.5): if d > T: return d #if d <= T: return 0 else: return 0 #return 0 N = 4 A = np.random.uniform(size=N**2) A.shape = (N,N) print A f = np.vectorize(my_func) print f(A) $ python x.py [[ 0.86913815 0.96833127 0.54539153 0.46184594] [ 0.46550903 0.24645558 0.26988519 0.0959257 ] [ 0.73356391 0.69363161 0.57222389 0.98214089] [ 0.15789303 0.06803493 0.01601389 0.04735725]] [[ 0.86913815 0.96833127 0.54539153 0. ] [ 0. 0. 0. 0. ] [ 0.73356391 0.69363161 0.57222389 0.98214089] [ 0. 0. 0. 0. ]] $ python x.py [[ 0.37127366 0.77935622 0.74392301 0.92626644] [ 0.61639086 0.32584431 0.12345342 0.17392298] [ 0.03679475 0.00536863 0.60936931 0.12761859] [ 0.49091897 0.21261635 0.37063752 0.23578082]] [[0 0 0 0] [0 0 0 0] [0 0 0 0] [0 0 0 0]]

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