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  • How do I stop a page from unloading (navigating away) in JS?

    - by Natalie Downe
    Does anyone know how to stop a page from reloading or navigating away? jQuery(function($) { /* global on unload notification */ warning = true; if(warning) { $(window).bind("unload", function() { if (confirm("Do you want to leave this page") == true) { //they pressed OK alert('ok'); } else { // they pressed Cancel alert('cancel'); return false; } }); } }); I am working on an e-commerce site at the moment, the page that displays your future orders has the ability to alter the quantities of items ordered using +/- buttons. Changing the quantities this way this doesn't actually change the order itself, they have to press confirm and therefore committing a positive action to change the order. However if they have changed the quantities and navigate away from the page I would like to warn them they are doing so in case this is an accident, as the changed quantities will be lost if they navigate away or refresh the page. In the code above I am using a global variable which will be false by default (its only true for testing), when a quantity is changed I will update this variable to be true, and when they confirm the changes I will set it to false. If warning is true and the page is unloaded, I offer them a confirmation box, if they say no they would like to stay on this page I need to stop it from unloading. return false isn't working, it still lets the user navigate away (the alerts are there for debugging only) Any ideas?

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  • Writing an auto-memoizer in Scheme. Help with macro and a wrapper.

    - by kunjaan
    I am facing a couple of problems while writing an auto-memoizer in Scheme. I have a working memoizer function, which creats a hash table and checks if the value is already computed. If it has been computed before then it returns the value else it calls the function. (define (memoizer fun) (let ((a-table (make-hash))) (?(n) (define false-if-fail (?() #f)) (let ((return-val (hash-ref a-table n false-if-fail))) (if return-val return-val (begin (hash-set! a-table n (fun n)) (hash-ref a-table n))))))) Now I want to create a memoize-wrapper function like this: (define (memoize-wrapper function) (set! function (memoizer function))) And hopefully create a macro called def-memo which defines the function with the memoize-wrapper. eg. the macro could expand to (memoizer (define function-name arguments body ...) or something like that. So that I should be able to do : (def-memo (factorial n) (cond ((= n 1) 1) (else (* n (factorial (- n 1)))))) which should create a memoized version of the factorial instead of the normal slow one. My problem is that the The memoize-wrapper is not working properly, it doesnt call the memoized function but the original function. I have no idea how to write a define inside of the macro. How do I make sure that I can get variable lenght arguments and variable length body? How do I then define the function and wrap it around with the memoizer? Thanks a lot.

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  • C++, array declaration, templates, linker error

    - by justik
    There is a linker error in my SW. I am using the following structure based on h, hpp, cpp files. Some classes are templatized, some not, some have function templates. Declaration: test.h #ifndef TEST_H #define TEST_H class Test { public: template <typename T> void foo1(); void foo2 () }; #include "test.hpp" #endif Definition: test.hpp #ifndef TEST_HPP #define TEST_HPP template <typename T> void Test::foo1() {} inline void Test::foo2() {} //or in cpp file #endif CPP file: test.cpp #include "test.h" void Test::foo2() {} //or in hpp file as inline I have the following problem. The variable vars[] is declared in my h file test.h #ifndef TEST_H #define TEST_H char *vars[] = { "first", "second"...}; class Test { public: void foo(); }; #include "test.hpp" #endif and used as a local variable inside foo() method defined in hpp file as inline. test.hpp #ifndef TEST_HPP #define TEST_HPP inline void Test::foo() { char *var = vars[0]; //A Linker Error } #endif However, the following linker error occurs: Error 745 error LNK2005: "char * * vars" (?vars@@3PAPADA) already defined in test2.obj How and where to declare vars[] to avoid linker errors? After including #include "test.hpp" it is late to declare it...

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  • Function returning a class containing a function returning a class

    - by Scott
    I'm working on an object-oriented Excel add-in to retrieve information from our ERP system's database. Here is an example of a function call: itemDescription = Macola.Item("12345").Description Macola is an instance of a class which takes care of database access. Item() is a function of the Macola class which returns an instance of an ItemMaster class. Description() is a function of the ItemMaster class. This is all working correctly. Items can be be stored in more than one location, so my next step is to do this: quantityOnHand = Macola.Item("12345").Location("A1").QuantityOnHand Location() is a function of the ItemMaster class which returns an instance of the ItemLocation class (well, in theory anyway). QuantityOnHand() is a function of the ItemLocation class. But for some reason, the ItemLocation class is not even being intialized. Public Function Location(inventoryLocation As String) As ItemLocation Set Location = New ItemLocation Location.Item = item_no Location.Code = inventoryLocation End Function In the above sample, the variable item_no is a member variable of the ItemMaster class. Oddly enough, I can successfully instantiate the ItemLocation class outside of the ItemMaster class in a non-class module. Dim test As New ItemLocation test.Item = "12345" test.Code = "A1" quantityOnHand = test.QuantityOnHand Is there some way to make this work the way I want? I'm trying to keep the API as simple as possible. So that it only takes one line of code to retrieve a value.

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  • How can I get HTML to link to a browser (or system) specified URL?

    - by MrHatken
    Hi All, I'd like to be able to create a "HTML link" that the user can click on and be taken to an URL (location) specified either in the browser (preferences?) or system environment. Is this possible? Any suggestions on how to do it please? For example, it may look something like this (or alternatively it could be a clickable image or even a submit button): "Click here to go to your preferred news site." When the user clicks on "here" the browser would go to a location specified not in the HTML but somehow in the browser (preferences?) or some system environment variable (OS specific etc.) Of course, the user would have to set up this preference or environment variable (or have some local application or better Web page that could set it - when approved by the user). This is sort of like most OS these days allow you to set "preferred app" for image processing or playing media. I would like to set preferred Web sites for certain tasks. Thanks for any suggestions. Hopefully with Javascript and modern browsers and perhaps HTML 5 something like this is possible. Cheers, Ashley.

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  • N3WB Question: passing objects in java?

    - by Adam Outler
    Hello, I am new at java. I am doing the following: Read from file, then put data into a variable. checkToken = lineToken.nextToken(); processlinetoken() } But then when I try to process it... public static void readFile(String fromFile) throws IOException { BufferedReader reader = new BufferedReader(new FileReader(fromFile)); String line = null; while ((line=reader.readLine()) != null ) { if (line.length() >= 2) { StringTokenizer lineToken = new StringTokenizer (line); checkToken = lineToken.nextToken(); ...... But here's where I come into a problem. public static void processlinetoken() checkToken=lineToken.nextToken(); } it fails out. Exception in thread "main" java.lang.Error: Unresolved compilation problem: The method nextToken() is undefined for the type String at testread.getEngineLoad(testread.java:243) at testread.readFile(testread.java:149) at testread.main(testread.java:119) so how do I get this to work? It seems to pass the variable, but nothing after the . works.

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  • How to access the members of this data in PHP?

    - by George Edison
    Okay. Now I give up. I have been playing with this for hours. I have a variable name $data. The variable contains these contents: (extracted by using var_export()) array ( 'headers' => array ( 'content-type' => 'multipart/alternative; boundary="_689e1a7d-7a0a-442a-bd6c-a1fb1dc2993e_"', ), 'ctype_parameters' => array ( 'boundary' => '_689e1a7d-7a0a-442a-bd6c-a1fb1dc2993e_', ), 'parts' => array ( 0 => stdClass::__set_state(array( 'headers' => array ( 'content-type' => 'text/plain; charset="iso-8859-1"', 'content-transfer-encoding' => 'quoted-printable', ), 'ctype_primary' => 'text', )), ), ) I removed some non-essential data. I want to access the headers value (on the second line above) - simple: $data->headers I want to access the headers value (on the fourteenth line after the stdClass:: stuff) - how? How can I possibly access the values within the stdClass::__set_state section? I tried var_export($data->parts); but all I get is NULL

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  • Problem in displaying image in FireFox

    - by Param-Ganak
    Hello friends, I have a JSP page on which I have a div tag in which there is a a IMG tag. Using this IMG tag I want to show an image in it. Here the source path of an image is comes from database so I assigned a JSP variable using JSP scriplet. This JSP variable have the source path of an image. This path of image may be of different machine or of same machine i.e. images are stored on different machine or on same machine i.e. on local machine on different drive. The problem is that how to give path of image stored on different machine as well as on same machine. I have tried different ways like by giving ip address of that machine. Here is the path that of local machine where the image is stored img src= file:\localhost\D:\ScannedSheets\testproj/batch1/IMG001.jpg style="z-index:1; position:absolute; top:0; left:0; width:850; height:1099" With this syntax the image is visible in Internet Explorer but With the same syntax Its not visible in FireFox, Google Chrome etc. Please Guide me in friends. Also tell me that how to give path of the image stored on different machine which works In Internet Explorer, FireFox, Google chrome etc.

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  • How do I refer to a windows form control by name (C# / VB)

    - by Alex
    Suppose I have a label control on a windows form called "UserName". How can I refer to that label programmatically using the label name? For example I can do: For each ctrl as Control in TabPage.Controls If ctrl.Name = "UserName" Then ' Do something End If Next This seems quite inefficient. I would like to do something like: TabPage.Controls("UserName").Text = "Something" I did some googling but couldn't find a satisfactory answer. Most suggested looping, some said .NET 2005 doesn't support direct refenece using string name, and FindControl method was asp.net only... EDIT Thanks for the response so far. Here is a bit more detail. I have a windows form with three tabpages, all of which a very similar in design and function i.e. same drop down menus, labels, react in simlar way to events etc. Rather than write code for each event per tabpage I have built a class that controls the events etc. per tabpage. For example, on each tabpage there is a Label called "RecordCounter" that simply shows the number of rows in the datagridview when it is populated by selection of a variable in a drop down menu. So what I want to be able to do is, upon selection of a variable in the drop down menu, the datagridview populates itself with data, and then I simply want to display the number of rows in a label ("RecordCounter"). This is exactly the same process on each tabpage so what I am doing is passing the tabpage to the class and then I want to be able to refer to the "RecordCounter" and then update it. In my class I set the ActivePage property to be the TabPage that the user has selected and then want to be able to do something like: ActivePage.RecordCounter.Text = GetNumberOfRows()

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  • "for" loop from program 7.6 from Kochan's "Programming in Objective-C"

    - by Mr_Vlasov
    "The sigma notation is shorthand for a summation. Its use here means to add the values of 1/2^i, where i varies from 1 to n. That is, add 1/2 + 1/4 + 1/8 .... If you make the value of n large enough, the sum of this series should approach 1. Let’s experiment with different values for n to see how close we get." #import "Fraction.h" int main (int argc, char *argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; Fraction *aFraction = [[Fraction alloc] init]; Fraction *sum = [[Fraction alloc] init], *sum2; int i, n, pow2; [sum setTo: 0 over: 1]; // set 1st fraction to 0 NSLog (@"Enter your value for n:"); scanf ("%i", &n); pow2 = 2; for (i = 1; i <= n; ++i) { [aFraction setTo: 1 over: pow2]; sum2 = [sum add: aFraction]; [sum release]; // release previous sum sum = sum2; pow2 *= 2; } NSLog (@"After %i iterations, the sum is %g", n, [sum convertToNum]); [aFraction release]; [sum release]; [pool drain]; return 0; } Question: Why do we have to create additional variable sum2 that we are using in the "for" loop? Why do we need "release previous sum" here and then again give it a value that we just released? : sum2 = [sum add: aFraction]; [sum release]; // release previous sum sum = sum2; Is it just for the sake of avoiding memory leakage? (method "add" initializes a variable that is stored in sum2)

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  • Does Interlocked guarantee visibility to other threads in C# or do I still have to use volatile?

    - by Lirik
    I've been reading the answer to a similar question, but I'm still a little confused... Abel had a great answer, but this is the part that I'm unsure about: ...declaring a variable volatile makes it volatile for every single access. It is impossible to force this behavior any other way, hence volatile cannot be replaced with Interlocked. This is needed in scenarios where other libraries, interfaces or hardware can access your variable and update it anytime, or need the most recent version. Does Interlocked guarantee visibility of the atomic operation to all threads, or do I still have to use the volatile keyword on the value in order to guarantee visibility of the change? Here is my example: public class CountDownLatch { private volatile int m_remain; // <--- do I need the volatile keyword there since I'm using Interlocked? private EventWaitHandle m_event; public CountDownLatch (int count) { Reset(count); } public void Reset(int count) { if (count < 0) throw new ArgumentOutOfRangeException(); m_remain = count; m_event = new ManualResetEvent(false); if (m_remain == 0) { m_event.Set(); } } public void Signal() { // The last thread to signal also sets the event. if (Interlocked.Decrement(ref m_remain) == 0) m_event.Set(); } public void Wait() { m_event.WaitOne(); } }

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  • GADTs and Scrap your Boilerplate

    - by finnsson
    I'm writing a XML (de)serializer using Text.XML.Light and Scrap your Boilerplate (at http://github.com/finnsson/Text.XML.Generic) and so far I got working code for "normal" ADTs but I'm stuck at deserializing GADTs. I got the GADT data DataBox where DataBox :: (Show d, Eq d, Data d) => d -> DataBox and I'm trying to get this to compile instance Data DataBox where gfoldl k z (DataBox d) = z DataBox `k` d gunfold k z c = k (z DataBox) -- not OK toConstr (DataBox d) = toConstr d dataTypeOf (DataBox d) = dataTypeOf d but I can't figure out how to implement gunfold for DataBox. The error message is Text/XML/Generic.hs:274:23: Ambiguous type variable `b' in the constraints: `Eq b' arising from a use of `DataBox' at Text/XML/Generic.hs:274:23-29 `Show b' arising from a use of `DataBox' at Text/XML/Generic.hs:274:23-29 `Data b' arising from a use of `k' at Text/XML/Generic.hs:274:18-30 Probable fix: add a type signature that fixes these type variable(s) It's complaining about not being able to figure out the data type of b. I'm also trying to implement dataCast1 and dataCast2 but I think I can live without them (i.e. an incorrect implementation). I guess my questions are: Is it possible to combine GADTs with Scrap your Boilerplate? If so: how do you implement gunfold for a GADT?

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  • How to throw meaningful data in exceptions ?

    - by ZeroCool
    I would like to throw exceptions with meaningful explanation ! I thought of using variable arguments worked fine but lately I figured out it's impossible to extend the class in order to implement other exception types. So I figured out using an std::ostreamstring as a an internal buffer to deal with formatting ... but doesn't compile! I guess it has something to deal with copy constructors. Anyhow here is my piece of code: class Exception: public std::exception { public: Exception(const char *fmt, ...); Exception(const char *fname, const char *funcname, int line, const char *fmt, ...); //std::ostringstream &Get() { return os_ ; } ~Exception() throw(); virtual const char *what() const throw(); protected: char err_msg_[ERRBUFSIZ]; //std::ostringstream os_; }; The variable argumens constructor can't be inherited from! this is why I thought of std::ostringstream! Any advice on how to implement such approach ?

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  • Asynchronous javascript issue

    - by amit
    I am trying to create a function which takes values from various html elements of the page to create a string and pass on to a variable. now this works great for all browsers except IE 8 and 9. IE tends to skip the part of fetching the values and goes straight to the variable and finds nothing.. is there a way to sync it all so that it works in IE? function seturl() { var qstring = returnQString(); $('span.keyword').text($.trim($('#hdnKeyWord').attr('value'))); $('input.search_box').attr('value', $.trim($('#hdnKeyWord').attr('value'))); $('#hdnSearchKeyword').attr('value', $.trim($('#hdnKeyWord').attr('value'))); $(".search_box").val($.trim($("#hdn_span_hdnKeyWord").text())); $(".header_inner input[type='text']").focus(); $(".search_term input[type='text']").focus(); $('#locationurl').attr('value', qstring); } function returnQString(){ var qstring = $.trim($('#locationurl').attr('init')); //initial value of the url qstring += "?type=" + $('#hdnSTSearch').attr('value'); // type of handler hit qstring += "&keyword=" + encodeURIComponent($('#hdnKeyWord').attr('value')); // keyword addition qstring += "&pagestart=" + $('#current_page').attr('value'); // pagestart(current page) addition qstring += "&pagesize=" + $('#show_per_page').attr('value'); // per page size addition qstring += "&facets=" // facetsearch $.each(selectedFilter.items, function (index, value) { qstring += value.filter + ","; }); qstring += "&selectedSection=" + selectedSection // Section Select return qstring; }

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  • Best way to design a class in python

    - by Fraz
    So, this is more like a philosophical question for someone who is trying to understand classes. Most of time, how i use class is actually a very bad way to use it. I think of a lot of functions and after a time just indent the code and makes it a class and replacing few stuff with self.variable if a variable is repeated a lot. (I know its bad practise) But anyways... What i am asking is: class FooBar: def __init__(self,foo,bar): self._foo = foo self._bar = bar self.ans = self.__execute() def __execute(self): return something(self._foo, self._bar) Now there are many ways to do this: class FooBar: def __init__(self,foo): self._foo = foo def execute(self,bar): return something(self._foo, bar) Can you suggest which one is bad and which one is worse? or any other way to do this. This is just a toy example (offcourse). I mean, there is no need to have a class here if there is one function.. but lets say in __execute something() calls a whole set of other methods.. ?? Thanks

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  • xslt check for alpha numeric character

    - by Newcoma
    I want to check if a string contains only alphanumeric characters OR '.' This is my code. But it only works if $value matches $allowed-characters exactly. I use xslt 1.0. <xsl:template name="GetLastSegment"> <xsl:param name="value" /> <xsl:param name="separator" select="'.'" /> <xsl:variable name="allowed-characters">ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.</xsl:variable> <xsl:choose> <xsl:when test="contains($value, $allowed-characters)"> <xsl:call-template name="GetLastSegment"> <xsl:with-param name="value" select="substring-after($value, $separator)" /> <xsl:with-param name="separator" select="$separator" /> </xsl:call-template> </xsl:when> <xsl:otherwise> <xsl:value-of select="$value" /> </xsl:otherwise> </xsl:choose> </xsl:template>

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  • CDN for Images in ASP.NET

    - by Chris
    I am in the process of moving all of the images in my web application over to a CDN but I want to easily be able to switch the CDN on or off without having to hard code the path to the images. My first thought was to add an HttpHandler for image extensions that depending whether a variable in the web.config (something like ) will serve the image from the server or from the CDN. But after giving this a little though I think I've essentially ruled this out as it will cause ASP.NET to handle the request for every single image, thus adding overhead, and it might actually completely mitigate the benefits of using a CDN. An alternative approach is, since all of my pages inherit from a base page class, I could create a function in the base class that determines what path to serve the files from based off the web.config variable. I would then do something like this in the markup: <img src='<%= GetImagePath()/image.png' /> I think this is probably what I'll have to end up doing, but it seems a little clunky to me. I also envision problems with the old .NET error of not being able to modify the control collection because of the "<%=" though the "<%#" solution will probably work. Any thoughts or ideas on how to implement this?

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  • how to emulate thread local storage at user space in C++ ?

    - by vprajan
    I am working on a mobile platform over Nucleus RTOS. It uses Nucleus Threading system but it doesn't have support for explicit thread local storage i.e, TlsAlloc, TlsSetValue, TlsGetValue, TlsFree APIs. The platform doesn't have user space pthreads as well. I found that __thread storage modifier is present in most of the C++ compilers. But i don't know how to make it work for my kind of usage. How does __thread keyword can be mapped with explicit thread local storage? I read many articles but nothing is so clear for giving me the following basic information will __thread variable different for each thread ? How to write to that and read from it ? does each thread has exactly one copy of the variable ? following is the pthread based implementation: pthread_key_t m_key; struct Data : Noncopyable { Data(T* value, void* owner) : value(value), owner(owner) {} int* value; }; inline ThreadSpecific() { int error = pthread_key_create(&m_key, destroy); if (error) CRASH(); } inline ~ThreadSpecific() { pthread_key_delete(m_key); // Does not invoke destructor functions. } inline T* get() { Data* data = static_cast<Data*>(pthread_getspecific(m_key)); return data ? data->value : 0; } inline void set(T* ptr) { ASSERT(!get()); pthread_setspecific(m_key, new Data(ptr, this)); } How to make the above code use __thread way to set & get specific value ? where/when does the create & delete happen? If this is not possible, how to write custom pthread_setspecific, pthread_getspecific kind of APIs. I tried using a C++ global map and index it uniquely for each thread and retrieved data from it. But it didn't work well.

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  • How do I put my return data from an asmx into JSON?

    - by jphenow
    I want to return an array of javascript objects from my asp.net asmx file. ie. variable = [ { *value1*: 'value1', *value2*: 'value2', ..., }, { . . } ]; I seem have been having trouble reaching this. I'd put this into code but I've been hacking away at it so much it'd probably do more harm than good in having this answered. Basically I am using a web service to find names as people type the name. I'd use a regular text file or something but its a huge database that's always changing - and don't worry I've indexed the names so searching can be a little snappier - but I would really prefer to stick with this method and just figure out how to get usable JSON back to javascript. I've seen a few that sort of attempt to describe how one would approach this but I honestly think microsofts articles are damn near unreadable. Thanks in advance for assistance. EDIT: I'm using the $.ajax() function from jQuery - I've had it working but it seems like I was doing it in bad practice not returning and using actual JSON. Previously I'd take a string back and insert it into html to use the variable it set - very roundabout.

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  • Efficient way to get highly correlated pairs from large data set in Python or R

    - by Akavall
    I have a large data set (Let's say 10,000 variables with about 1000 elements each), we can think of it as 2D list, something like: [[variable_1], [variable_2], ............ [variable_n] ] I want to extract highly correlated variable pairs from that data. I want "highly correlated" to be a parameter that I can choose. I don't need all pairs to be extracted, and I don't necessarily want the most correlated pairs. As long as there is an efficient method that gets me highly correlated pairs I am happy. Also, it would be nice if a variable does not show up in more than one pair. Although this might not be crucial. Of course, there is a brute force way to finding such pairs, but it is too slow for me. I've googled around for a bit and found some theoretical work on this issue, but I wasn't able for find a package that could do what I am looking for. I mostly work in python, so a package in python would be most helpful, but if there exists a package in R that does what I am looking for it will be great. Does anyone know of a package that does the above in Python or R? Or any other ideas? Thank You in Advance

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  • ruby on rails basics help

    - by CHID
    Hi, i created a scaffolded application in rails by the name of product. The product_controller.rb file contains the following. class ProductsController ApplicationController def new @product = Product.new respond_to do |format| format.html # new.html.erb format.xml { render :xml = @product } end end def create @product = Product.new(params[:product]) respond_to do |format| if @product.save flash[:notice] = 'Product was successfully created.' format.html { redirect_to(@product) } format.xml { render :xml = @product, :status = :created, :location = @product } else format.html { render :action = "new" } format.xml { render :xml = @product.errors, :status = :unprocessable_entity } end end end Now when the url http://localhost:3000/products/create is given Where new product link is clicked, control is transferred to new definition in the controller class and then an instance variable @product is created. BUT WHERE IS THIS VARIABLE PASSED? The funtion inturn calls new.rhtml which contains <% form_for(@product) do |f| % #all form elments declaration <% f.submit "Create" % <%= end % Here @product is initialized in the controller file and passed to this new.rhtml. So where does form_for(@product) gets the data? How does the control gets tranfered to create function in controller file when submit button is clicked? No where action is specified to the controller file. in the create function, wat does redirec_to(@product) specify where @product is an object received from the new.html file... I am very much confused on the basics of ROR. Somone pls help me clarify this. pardon me for making such a big post. I have lots of doubts in this single piece of code

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  • Data conversion from accelerometer

    - by mrigendra
    Hi all I am working on an accelerometer bma220 , and its datasheet says that data is in 2's complement form.So what i had to do was getting that 8 bit data in any 8 bit signed char and done. the bma220 have an 8 bit register of which first 6 bits are data and last two are zero. void properdata(int16_t *msgData) { printf("\nin proper data\n"); int16_t temp, i; for(i=0; i<3; i++) { temp = *(msgData + i); printf("temp = %d sense = %d\n", temp, sense); temp = temp >> 2; // only 6 bits data temp = temp / sense; //decimal value * .0625 = value in g printf("temp = %d\n", temp); } } in this program i am taking data in a unsigned variable msgdata and doing all the calculations on a signed variable. I just need to know if this is the correct way to convert data?

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  • Haskell: Dealing With Types And Exceptions

    - by Douglas Brunner
    I'd like to know the "Haskell way" to catch and handle exceptions. As shown below, I understand the basic syntax, but I'm not sure how to deal with the type system in this situation. The below code attempts to return the value of the requested environment variable. Obviously if that variable isn't there I want to catch the exception and return Nothing. getEnvVar x = do { var <- getEnv x; Just var; } `catch` \ex -> do { Nothing } Here is the error: Couldn't match expected type `IO a' against inferred type `Maybe String' In the expression: Just var In the first argument of `catch', namely `do { var <- getEnv x; Just var }' In the expression: do { var <- getEnv x; Just var } `catch` \ ex -> do { Nothing } I could return string values: getRequestURI x = do { requestURI <- getEnv x; return requestURI; } `catch` \ex -> do { return "" } however, this doesn't feel like the Haskell way. What is the Haskell way?

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  • Working with Java using methods and arrays [closed]

    - by jordan
    Hi i'm a newb at java and for one of my labs I have to create a instant messenger client with these requirements: add buddyList instance variable add IMClient constructor to create ArrayList addBuddy method removeBuddy method findBuddy method printBuddyList method what's the best way to go about this? so far I have this: public class IMClient { private String userId; // User id private String password; // Password private int status; // Status code for user: 1 - Online, 2 - Off-line, 3 - Away public IMClient(String userId, String password, int status) { super(); this.userId = userId; this.password = password; this.status = status; } // Returns true if password as a parameter matches password instance variable. public boolean checkPassword(String password) { return this.password.equals(password); } public String toString() { StringBuffer buf = new StringBuffer(100); buf.append(" User id: "); buf.append(userId); buf.append(" Password: "); buf.append(password); buf.append(" Status: "); buf.append(status); return buf.toString(); } public String getUserId() { return userId; } public void setUserId(String userId) { this.userId = userId; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public int getStatus() { return status; } public void setStatus(int status) { this.status = status; } public static void main(String[] args) { } }

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  • How make this jquery function reusable?

    - by Pandiya Chendur
    Comsider this jquery function, function showresults(jsonobj) { $.each(jsonobj, function(i, employee) { divs += '<div class="resultsdiv"><br /><span style="display: inline-block;width:150px;" class="resultName">' + employee.Emp_Name + '</span><span class="resultfields" style="padding-left:100px;">Category&nbsp;:</span>&nbsp;<span class="resultfieldvalues">' + employee.Desig_Name + '</span><br /><br /><span id="SalaryBasis" class="resultfields">Salary Basis&nbsp;:</span>&nbsp;<span class="resultfieldvalues">' + employee.SalaryBasis + '</span><span class="resultfields" style="padding-left:25px;">Salary&nbsp;:</span>&nbsp;<span class="resultfieldvalues">' + employee.FixedSalary + '</span><span style="font-size:110%;font-weight:bolder;padding-left:25px;">Address&nbsp;:</span>&nbsp;<span class="resultfieldvalues">' + employee.Address + '</span></div>'; }); } Here i am iterating my json data and drawing div elements.... As you see these div elements are hardcoded how to pass these html div elements dynamically by a variable... var divs=<div></div> function showresults(jsonobj,divs) { $.each(jsonobj, function(i, employee) { divs += divs Is this correct way of doing but there will be an error employee object wont be there know when my divs variable declared outside the function... Any suggestion...

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