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• How to overcome the programmer's block ?

  - by Nicolas Dorier

  How do you do when, during the development of your application, you can't decide yourself what to do next. You have no problem technically speaking, you have no problem to write clean code BUT you have a problem to decide yourself on what to code now. And you spend time thinking and thinking again on your design, in the car, in the shower, and you cannot write a single line of code... I think we call this "analysis paralysis". I hate being in this state ! How can you avoid this ? How do you do to not fall in this state ? I think this occurs when we are writting a big chunk of code with no visible improvement, but I'm not sure... UPDATE Like some of you said, this problem is also what we call the "programmer's block" (analogy with the writer's block). Doing some TDD doesn't help because I'm stuck, I can't decide myself what class to code, what methods to put inside (even a name of method). Though I admit that it helps to break a big chunk of code into smaller ones. Like Talesh said my head becomes full of "what-if".

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• Stop an executing recursive javascript function

  - by DA

  Using jQuery, I've build an image/slide rotator. The basic setup is (in pseudocode): function setupUpSlide(SlideToStartWith){ var thisSlide = SlideToStartWith; ...set things up... fadeInSlide(thisSlide) } function fadeInSlide(thisSlide){ ...fade in this slide... fadeOutSlide(thisSlide) } function fadeOutSlide(thisSlide){ ...fade out this slide... setupUpSlide(nextSlide) } I call the first function and pass in a particular slide index, and then it does its thing calling chain of functions which then, in turn, calls the first function again passing in the next index. This then repeats infinitely (resetting the index when it gets to the last item). This works just fine. What I want to do now is allow someone to over-ride the slide show by being able to click on a particular slide number. Therefore, if slide #8 is showing and I click #3, I want the recursion to stop and then call the initial function passing in slide #3, which then, in turn, will start the process again. But I'm not sure how to go about that. How does one properly 'break' a recursive script. Should I create some sort of global 'watch' variable that if at any time is 'true' will return: false and allow the new function to execute?

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• HTML5 audio object doesn't play on iPad (when called from a setTimeout)

  - by Dan Halliday

  I have a page with a hidden <audio> object which is being started and stopped using a custom button via javascript. (The reason being I want to customise the button, and that drawing an audio player seems to destroy rendering performance on iPad anyway). A simplified example (in coffeescript): // Works fine on all browsers constructor: (@_button, @_audio) -> @_button.on 'click', @_play // Bind button's click event with jQuery _play: (e) => @_audio[0].play() // Call play() on audio element The audio plays fine when triggered from a function bound to a click event, but I actually want an animation to complete before the file plays so I put .play() inside a setTimeout. However I just can't get this to work: // Will not play on iPad constructor: (@_button, @_audio) -> @_button.on 'click', @_play // Bind button's click event with jQuery _play: (e) => setTimeout (=> // Declare a 300ms timeout @_audio[0].play() // Call play() on audio element ), 300 I've checked that @_audio (this._audio) is in scope and that its play() method exists. Why doesn't this work on iPad?

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• what use does the javascript forEach method have (that map can't do)?

  - by JohnMerlino

  Hey all, The only difference I see in map and foreach is that map is returning an array and foreach is not. However, I don't even understand the last line of the foreach method "func.call(scope, this[i], i, this);". For example, isn't "this" and "scope" referring to same object and isn't this[i] and i referring to the current value in the loop? I noticed on another post someone said "Use forEach when you want to do something on the basis of each element of the list. You might be adding things to the page, for example. Essentially, it's great for when you want "side effects". I don't know what is meant by side effects. Array.prototype.map = function(fnc) { var a = new Array(this.length); for (var i = 0; i < this.length; i++) { a[i] = fnc(this[i]); } return a; } Array.prototype.forEach = function(func, scope) { scope = scope || this; for (var i = 0, l = this.length; i < l; i++) func.call(scope, this[i], i, this); } Finally, are there any real uses for these methods in javascript (since we aren't updating a database) other than to manipulate numbers like this: alert([1,2,3,4].map(function(x){ return x + 1})); //this is the only example I ever see of map in javascript. Thanks for any reply.

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• MySQL db Audit Trail Trigger

  - by Natkeeran

  I need to track changes (audit trail) in certain tables in a MySql Db. I am trying to implement the solution suggested here. I have an AuditLog Table with the following columns: AuditLogID, TableName, RowPK, FieldName, OldValue, NewValue, TimeStamp. The mysql stored procedure is the following (this executes fine, and creates the procedure): The call to the procedure such as: CALL addLogTrigger('ProductTypes', 'ProductTypeID'); executes, but does not create any triggers (see the image). SHOW TRIGGERS returns empty set. Please let me know what could be the issue, or an alternate way to implement this. DROP PROCEDURE IF EXISTS addLogTrigger; DELIMITER $ CREATE PROCEDURE addLogTrigger(IN tableName VARCHAR(255), IN pkField VARCHAR(255)) BEGIN SELECT CONCAT( 'DELIMITER $\n', 'CREATE TRIGGER ', tableName, '_AU AFTER UPDATE ON ', tableName, ' FOR EACH ROW BEGIN ', GROUP_CONCAT( CONCAT( 'IF NOT( OLD.', column_name, ' <=> NEW.', column_name, ') THEN INSERT INTO AuditLog (', 'TableName, ', 'RowPK, ', 'FieldName, ', 'OldValue, ', 'NewValue' ') VALUES ( ''', table_name, ''', NEW.', pkField, ', ''', column_name, ''', OLD.', column_name, ', NEW.', column_name, '); END IF;' ) SEPARATOR ' ' ), ' END;$' ) FROM information_schema.columns WHERE table_schema = database() AND table_name = tableName; END$ DELIMITER ;

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• Widget host app with custom view - onClick is not triggered in the app widget.

  - by Dennis K

  I'm writing an app that will host widgets. The app has custom view (which probably is the source of issue). I obtain AppWidgetHostView like this private AppWidgetHostView widget; ... AppWidgetProviderInfo appWidgetInfo = mAppWidgetManager.getAppWidgetInfo(appWidgetId); widget = mAppWidgetHost.createView(this, appWidgetId, appWidgetInfo); widget.setAppWidget(appWidgetId, appWidgetInfo); mView.addWidget(widget, appWidgetInfo); mView.addWidget() basically just remembers this AppWidgetHostView instance and then draws it directly onto canvas. Visually everything is fine - I can see the actual widget. But the issue is with reacting on UI events. Please advise what needs to be done in the parent view in order to correctly trigger handlers in the widgets like onClick(). Notes: I used standard widgets which normally react on click events. None worked. I also created my own test widget with listener (via views.setOnClickPendingIntent(R.id.appwidget_text, pending);) and onClick() is successfully triggered if the widget is added on Homescreen, but doesn't work in my app. mView correctly detects click event and I tried to call widget.performClick() there, which returns false meaning onClickListener is not registered in the widget. But according to source mAppWidgetHost.createView() would call updateAppWidget which would register its onClick listener.. Please advise where to look at. Thanks

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• Handling Application Logic in Multiple AsyncTask onPostExecute()s

  - by stormin986

  I have three simultaneous instances of an AsyncTask for download three files. When two particular ones finish, at the end of onPostExecute() I check a flag set by each, and if both are true, I call startActivity() for the next Activity. I am currently seeing the activity called twice, or something that resembles this type of behavior. Since the screen does that 'swipe left' kind of transition to the next activity, it sometimes does it twice (and when I hit back, it goes back to the same activity). It's obvious two versions of the activity that SHOULD only get called once are being put on the Activity stack. The only way I can find that this is possible is if both AsyncTasks' onPostExecute() executed SO simultaneously that they were virtually running the same lines at the same time, since I set the 'itemXdownloaded' flag to true right before I check for both and call startActivity(). But this is happening enough that it's very hard for me to believe that both downloads are finishing precisely at the same time and having their onPostExecute()s so close together... Any thoughts on what could be going on here? General gist of code (details removed, ignore any syntactical errors I may have edited in): // In onPostExecute() switch (downloadID) { case DL1: dl1complete = true; break; case DL2: dl2complete = true; break; case DL3: dl3complete = true; break; } // If 1 and 2 are done, move on (DL3 still going in background) if ( downloadID != DL3 && dl1complete && dl2complete) { ParentClass.this.startActivity(new Intent(ParentClass.this, NextActivity.class)); }

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• Bulletin board - Database optimisation

  - by andrew

  This question is a follow on from this Question The project and problem The project I am currently working on is a bulletin board for a large non-profit organisation. The bulletin board will be used to allow inter-office communication within the organisation. I am building the application and have been having trouble extracting the results that I need from my database because I don't think it is properly normalized and because of limitations in my knowledge of relational database theory and mysql. I would appreciate input into the design of the board in general and in particular, ways that the database structure can be improved to facilitate efficient queries and help me develop this application and future application faster Business Logic The bulletin board will be used in the following way Posting bulletins and responses to bulletins Employees or 'users' in offices around the country will be able to post messages to the bulletin board.Bulletins must be posted to a location and categorised- i'll call these "bulletins". Users will be able to post any number of replies to any one bulletin and users will be able to reply to their own bulletin - i'll call these 'replies'. Rating bulletins and replies Users will be able to either 'like' or 'dislike' a bulletin or a reply and the total number of likes or dislikes will be shown for each bulletin or reply. Viewing the bulletin board and responses Bulletins can be displayed chronologically. Users can sort bulletins chronologically or chronologically by the latest reply to that bulletin(let me know if you need more explanation) When a particular bulletin is selected, replies to that bulletin will be displayed chronologically @PerformanceDBA - edited 10:34 est 28/12/10I have begun implementing the data model. I assume that the 6th data model is the physical model because it contains the associative tables. I am going to post any questions that I have below. I will put up a database dump once I am done. I will then put up a list of all the queries that I need to run on the database and begin writing them. I hope you had a good Christmas. I'm in Canada and there's snow! Implementation of Physical model

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• How to get rid of the 'progress' cursor?

  - by Ivan

  I have an interval that launches an AJAX call to check if there is any update for the page (I imagine that it's similar to the mechanism used by Facebook or StackExchange to check for new notifications). The problem is that this call changes the cursor to the 'progress' or 'busy' cursor (visual problem) and disables to option to click on links (functional problem). I suppose both problems are related. How can get rid of this effect or at least minimize the consequences? Some code: setInterval(function() { try { var mid = $($("ul#alert-messages li.regular")[0]).attr('ref'); call_ajax('/load_alerts', {num:0, id:mid}, function (data) { if (data.ok) { for (var i=0; i<data.result.length; i++) { // .... } // ... } }, function() {}, // Do not show any error for this!! false); // Do not change cursor! } catch (e) {} }, 15000); function call_ajax(url, data, fnSuccess, fnError) { $.ajax({ 'url': url, 'type': 'POST', 'data': data, 'dataType': "json", 'success' : function(data) { if (fnSuccess) { fnSuccess(data); } else { if (typeof data.msg != 'undefined') { topBar(data.msg, typeof data.ok != 'undefined' && data.ok? 'message' : 'error'); } } }, error : function (jqXHR, textStatus, errorThrown) { console.log(errorThrown); if (fnError) { fnError(STR_ERROR_AJAX + textStatus); } else { topBar(STR_ERROR_AJAX + textStatus, 'error'); } } }); }

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• tracd server problems

  - by deddihp

  Hello, I got the following error while accessing tracd server, what's going on ? Thanks. [oke@localhost Trac-0.11.7]$ sudo tracd -p 8000 /home/deddihp/trac/ Server starting in PID 5082. Serving on 0.0.0.0:8000 view at http://127.0.0.1:8000/ ---------------------------------------- Exception happened during processing of request from ('127.0.0.1', 47804) Traceback (most recent call last): File "/usr/lib/python2.6/SocketServer.py", line 558, in process_request_thread self.finish_request(request, client_address) File "/usr/lib/python2.6/SocketServer.py", line 320, in finish_request self.RequestHandlerClass(request, client_address, self) File "/usr/lib/python2.6/SocketServer.py", line 615, in __init__ self.handle() File "/usr/lib/python2.6/BaseHTTPServer.py", line 329, in handle self.handle_one_request() File "/usr/lib/python2.6/site-packages/Trac-0.11.7-py2.6.egg/trac/web/wsgi.py", line 194, in handle_one_request gateway.run(self.server.application) File "/usr/lib/python2.6/site-packages/Trac-0.11.7-py2.6.egg/trac/web/wsgi.py", line 94, in run response = application(self.environ, self._start_response) File "/usr/lib/python2.6/site-packages/Trac-0.11.7-py2.6.egg/trac/web/standalone.py", line 100, in __call__ return self.application(environ, start_response) File "/usr/lib/python2.6/site-packages/Trac-0.11.7-py2.6.egg/trac/web/main.py", line 346, in dispatch_request locale.setlocale(locale.LC_ALL, environ['trac.locale']) File "/usr/lib/python2.6/locale.py", line 513, in setlocale return _setlocale(category, locale) Error: unsupported locale setting ----------------------------------------

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• php class scope when calling a non-method function not accessing all class members

  - by Aglystas

  So I'm using a stand alone function from within a class that that uses the class it's being called from. Here's the function function catalogProductLink($product_id,$product_name,$categories=true) { //This is the class that the function is called from global $STATE; if ($categories) { //The $STATE->category_id is the property I want to access, which I can't if (is_array($STATE->category_id)) { foreach($STATE->category_id as $cat_id) { if ($cat_id == 0) continue; $str .= "c$cat_id/"; } } } $str .= catalogUrlKeywords($product_name).'-p'.$product_id.'.html'; return $str; } And here's the function call, which is being made from within the $STATE class. $redirect = catalogProductLink($this->product_id, $tempProd->product_name, true, false); The object that I need access to is the $STATE object that has been declared global. Prior to this function call there are lots of public properties populated, but when I look at the $STATE object within the function scope it loses all the properties but one, product_id. The property that matters for this function is the category_id property, which is an array of category id's. I'm wondering why I don't have access to all the public properties of the $STATE object and how I can get access to them.

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• Browser loading strategy, <head>...<body>

  - by Bin Chen

  I am inspecting some interesting behaviors of browser, I don't know it's in standard or not. If I put everythin inside <head></head>, the browser will only begin to render the page after all the resouces in head is retrieved. So I am thinking that put as little as possible things into head is one of the important website optimization techniques, is it right? My question is: If I put script/css in body or other parts of the html, how can I know that script has been loaded successfully so that I will not be calling a undefined function?

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• Start dependent application with eunit

  - by ruslander

  I start lager as a dependent application when I run a unit test but for some reason the code under test does not see it. -module(main_tests). -include_lib("eunit/include/eunit.hrl"). main_test_() -> {foreach, fun distr_setup/0, fun distr_cleanup/1, [ fun must_retain/1 ]}. must_retain(_) -> {"Should do ping pong when is fully initialized", fun() -> ?assertEqual(pong, abuse_counter:ping()) end}. %%------------------------------------------------------------------ distr_setup() -> abuse_counter:start_link(), ok. distr_cleanup(_) -> abuse_counter:stop(), ok. Here is the output of the log which is complaining that lager is not defined {undef,[{lager,info,["up and running"],[]} though in the run output is definitely there. Here is how I run it: erl -pa ebin/ ../../deps/*/ebin -s lager -eval 'eunit:test(main_tests,[verbose]), init:stop().' Fails with the output Eshell V5.10.2 (abort with ^G) 1> 17:13:31.506 [info] Application lager started on node nonode@nohost ======================== EUnit ======================== module 'main_tests' undefined 17:13:31.528 [error] CRASH REPORT Process <0.57.0> with 1 neighbours exited with reason: call to undefined function lager:info("up and running") in gen_server:init_it/6 line 328 *unexpected termination of test process* ::**{undef,[{lager,info,["up and running"],[]}**, {abuse_counter,init,1,[{file,"src/abuse_counter.erl"},{line,37}]}, {gen_server,init_it,6,[{file,"gen_server.erl"},{line,304}]}, {proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,239}]}]} ======================================================= Failed: 0. Skipped: 0. Passed: 0. One or more tests were cancelled. Already spent 3-4h hours on google and stack overflow but nothing seems to work. One option is to hide this call behind a ?INFO(Mgs) macro but do not like the idea. Any help will be highly appreciated.

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• Python calling class methods with the wrong number of parameters

  - by Hussain

  I'm just beginning to learn python. I wrote an example script to test OOP in python, but something very odd has happened. When I call a class method, Python is calling the function with one more parameter than given. Here is the code: 1. class Bar: 2. num1,num2 = 0,0 3. def __init__(num1,num2): 4. num1,num2 = num1,num2 5. def foo(): 6. if num1 num2: 7. print num1,'is greater than ',num2,'!' 8. elif num1 is num2: 9. print num1,' is equal to ',num2,'!' 10. else: 11. print num1,' is less than ',num2,'!' 12. a,b,t = 42,84,bar(a,b) 13. t.foo 14. 15. t.num1 = t.num1^t.num2 16. t.num2 = t.num2^t.num1 17. t.num1 = t.num1^t.num2 18. 19. t.foo 20. And the error message I get: python test.py Traceback (most recent call last): File "test.py", line 12, in a,b,t = 42,84,bar(a,b) NameError: name 'bar' is not defined Can anyone help? Thanks in advance

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• OSMF seek with Amazon Cloudfront

  - by giorrrgio

  I've written a little OSMF player that streams via RTMP from Amazon Cloudfront. There's a known issue, the mp3 duration is not correctly readed from metadata and thus the seek function is not working. I know there's a workaround implying the use of getStreamLength function of NetConnection, which I successfully implemented in a previous non-OSMF player, but now I don't know how and when to call it, in terms of OSMF Events and Traits. This code is not working: protected function initApp():void { //the pointer to the media var resource:URLResource = new URLResource( STREAMING_PATH ); // Create a mediafactory instance mediaFactory = new DefaultMediaFactory(); //creates and sets the MediaElement (generic) with a resource and path element = mediaFactory.createMediaElement( resource ); var loadTrait:NetStreamLoadTrait = element.getTrait(MediaTraitType.LOAD) as NetStreamLoadTrait; loadTrait.addEventListener(LoaderEvent.LOAD_STATE_CHANGE, _onLoaded); player = new MediaPlayer( element ); //Marker 5: Add MediaPlayer listeners for media size and current time change player.addEventListener( DisplayObjectEvent.MEDIA_SIZE_CHANGE, _onSizeChange ); player.addEventListener( TimeEvent.CURRENT_TIME_CHANGE, _onProgress ); initControlBar(); } private function onGetStreamLength(result:Object):void { Alert.show("The stream length is " + result + " seconds"); duration = Number(result); } private function _onLoaded(e:LoaderEvent):void { if (e.newState == LoadState.READY) { var loadTrait:NetStreamLoadTrait = player.media.getTrait(MediaTraitType.LOAD) as NetStreamLoadTrait; if (loadTrait && loadTrait.netStream) { var responder:Responder = new Responder(onGetStreamLength); loadTrait.connection.call("getStreamLength", responder, STREAMING_PATH); } } }

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• Constructor Overload Problem in C++ Inheritance

  - by metdos

  Here my code snippet: class Request { public: Request(void); ……….. } Request::Request(void) { qDebug()<<"Request: "<<"Hello World"; } class LoginRequest :public Request { public: LoginRequest(void); LoginRequest(QDomDocument); …………… } LoginRequest::LoginRequest(void) { qDebug()<<"LoginRequest: "<<"Hello World"; requestType=LOGIN; requestId=-1; } LoginRequest::LoginRequest(QDomDocument doc){ qDebug()<<"LoginRequest: "<<"Hello World with QDomDocument"; LoginRequest::LoginRequest(); xmlDoc_=doc; } When call constructor of Overrided LoginRequest LoginRequest *test=new LoginRequest(doc); I came up with this result: Request: Hello World LoginRequest: Hello World with QDomDocument Request: Hello World LoginRequest: Hello World Obviously both constructor of LoginRequest called REquest constructor. Is there any way to cape with this situation? I can construct another function that does the job I want to do and have both constructors call that function. But I wonder is there any solution?

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• Entity Framework 4 + POCO with custom classes and WCF contracts (serialization problem)

  - by eman

  Yesterday I worked on a project where I upgraded to Entity Framework 4 with the Repository pattern. In one post, I have read that it is necessary to turn off the custom tool generator classes and then write classes (same like entites) by hand. That I can do it, I used the POCO Entity Generator and then deleted the new generated files .tt and all subordinate .cs classes. Then I wrote the "entity classes" by myself. I added the repository pattern and implemented it in the business layer and then implemented a WCF layer, which should call the methods from the business layer. By calling an Insert (Add) method from the presentation layer and everything is OK. But if I call any method that should return some class, then I get an error like (the connection was interrupted by the server). I suppose there is a problem with the serialization or am I wrong? How can by this problem solved? I'm using Visual Studio S2010, Entity Framework 4, C#. UPDATE: I have uploaded the project and hope somebody can help me! link text UPDATE 2: My questions: Why is POCO good (pros/cons)? When should POCO be used? Is POCO + the repository pattern a good choice? Should POCO classes by written by myself or could I use auto generated POCO classes?

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• SWIG interface to receive an opaque struct reference in Java through function argument

  - by Beeo

  I am trying to use SWIG in order to use the Spotify API (libspotify) for Android: https://developer.spotify.com/technologies/libspotify/ I am having trouble defining the SWIG interface file to be able to successfully call the following native C function: sp_error sp_session_create(const sp_session_config * config, sp_session ** sess); Which in C would be called like this: //config struct defined previously sp_session *sess; sp_session_create(&config, &sess); But in Java I would need to call it like this: //config object defined previously sp_session javaSess = new sp_session(); sp_session_create(config, javaSess); sp_session is an opaque struct and is only defined in libspotify's API.h file as: typedef struct sp_session sp_session; I'm expecting the libspotify library to create it and give me a reference to it. The only thing I need that reference for then is to pass to other functions in the API. I believe the answer lies within the SWIG interface and typemaps, but I have been unsuccessful in trying to apply the examples I found in the documentation: http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_struct_pointer_pointer `http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_using_typemaps_return_arguments Help!

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• What Kind of Knowledge is Necessary For a Permon Who Does Not Have IT Background? [closed]

  - by skyflyer

  One of my colleagues joined our company, which by the way is a internet company, months ago as an on-line marketing specialist. He majored English in his college and has never deeply touched IT before. He says that to be a good on-line marketing specialist he needs to lean some basic IT skills in order to deliver superb work. According to him, things like Search Engine Optimization, monitoring competitors' web sites, design some functionality on web site and so on require IT entree-level knowledge. And he asks me what kind knowledge is helpful for him to do his job. I am stunted by his question. It is easy enough to answer, things like HTML, CSS, even Photo-shop are required in some job descriptions. Also, I believe some basic understanding of dynamic web site, static web site is helpful to him. On the other hand, as a techie I still feel my answer is awkward. What is your opinion on this? Always lot of thanks to you guys on SO.

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• ASP Function that returns result from stored procedures

  - by Brad

  I am working on a project that requires me to hop into to separate DB's. So I have figured that I need to have multiple functions inside of my VB page. The only problem I am having,is I am not to sure how to get this all accomplished. So far I have figured out the overall structure, just need help implementing that structure. Here is my idea: The main Function would call two other functions. We can Call them Sub Function 1 and Sub Function 2. So, the main Function takes the saved sessions information for the E-mail address and dumps in into Sub Function 1. It needs to open up a new connection to the db/stored procedure and RUN the following procedure and then return the result. Here is the stored procedure and what i think is correct. CREATE PROCEDURE WEB_User ( @EMAIL_ADDRESS varchar(80) = [EMAIL_ADDRESS] ) AS SELECT MEMBER_NUMBER FROM WEB_LOGIN WHERE EMAIL_ADDRESS = @EMAIL_ADDRESS So my question is, what is the function suppose to look like? how do I send the session information to the procedure? and finally, how do I return the stored procedure results and push back into the main function so it can be carried into sub function 2? Thank you in advance for your help... I really appreciate it!

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• Event type property lost in IE-8

  - by Channel72

  I've noticed a strange Javascript error which only seems to happen on Internet Explorer 8. Basically, on IE-8 if you have an event handler function which captures the event object in a closure, the event "type" property seems to become invalidated from within the closure. Here's a simple code snippet which reproduces the error: <html> <head> <script type = "text/javascript"> function handleClickEvent(ev) { ev = (ev || window.event); alert(ev.type); window.setTimeout(function() { alert(ev.type); // Causes error on IE-8 }, 20); } function foo() { var query = document.getElementById("query"); query.onclick = handleClickEvent; } </script> </head> <body> <input id = "query" type = "submit"> <script type = "text/javascript"> foo(); </script> </body> </html> So basically, what happens here is that within the handleClickEvent function, we have the event object ev. We call alert(ev.type) and we see the event type is "click". So far, so good. But then when we capture the event object in a closure, and then call alert(ev.type) again from within the closure, now all of a sudden Internet Explorer 8 errors, saying "Member not found" because of the expression ev.type. It seems as though the type property of the event object is mysteriously gone after we capture the event object in a closure. I tested this code snippet on Firefox, Safari and Chrome, and none of them report an error condition. But in IE-8, the event object seems to become somehow invalidated after it's captured in the closure. Question: Why is this happening in IE-8, and is there any workaround?

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• Why is this linq extension method hit the database twice?

  - by Pure.Krome

  Hi folks, I have an extension method called ToListIfNotNullOrEmpty(), which is hitting the DB twice, instead of once. The first time it returns one result, the second time it returns all the correct results. I'm pretty sure the first time it hits the database, is when the .Any() method is getting called. here's the code. public static IList<T> ToListIfNotNullOrEmpty<T>(this IEnumerable<T> value) { if (value.IsNullOrEmpty()) { return null; } if (value is IList<T>) { return (value as IList<T>); } return new List<T>(value); } public static bool IsNullOrEmpty<T>(this IEnumerable<T> value) { if (value != null) { return !value.Any(); } return true; } I'm hoping to refactor it so that, before the .Any() method is called, it actually enumerates through the entire list. If i do the following, only one DB call is made, because the list is already enumerated. var pewPew = (from x in whatever select x) .ToList() // This enumerates. .ToListIsNotNullOrEmpty(); // This checks the enumerated result. I sorta don't really want to call ToList() then my extension method. Any ideas, folks?

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• Boost Asio UDP retrieve last packet in socket buffer

  - by Alberto Toglia

  I have been messing around Boost Asio for some days now but I got stuck with this weird behavior. Please let me explain. Computer A is sending continuos udp packets every 500 ms to computer B, computer B desires to read A's packets with it own velocity but only wants A's last packet, obviously the most updated one. It has come to my attention that when I do a: mSocket.receive_from(boost::asio::buffer(mBuffer), mEndPoint); I can get OLD packets that were not processed (almost everytime). Does this make any sense? A friend of mine told me that sockets maintain a buffer of packets and therefore If I read with a lower frequency than the sender this could happen. ¡? So, the first question is how is it possible to receive the last packet and discard the ones I missed? Later I tried using the async example of the Boost documentation but found it did not do what I wanted. http://www.boost.org/doc/libs/1_36_0/doc/html/boost_asio/tutorial/tutdaytime6.html From what I could tell the async_receive_from should call the method "handle_receive" when a packet arrives, and that works for the first packet after the service was "run". If I wanted to keep listening the port I should call the async_receive_from again in the handle code. right? BUT what I found is that I start an infinite loop, it doesn't wait till the next packet, it just enters "handle_receive" again and again. I'm not doing a server application, a lot of things are going on (its a game), so my second question is, do I have to use threads to use the async receive method properly, is there some example with threads and async receive? Thanks for you attention.

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• Fetching just the Key/id from a ReferenceProperty in App Engine

  - by ozone

  Hi SO, I could use a little help in AppEngine land... Using the [Python] API I create relationships like this example from the docs: class Author(db.Model): name = db.StringProperty() class Story(db.Model): author = db.ReferenceProperty(Author) story = db.get(story_key) author_name = story.author.name As I understand it, that example will make two datastore queries. One to fetch the Story and then one to deference the Author inorder to access the name. But I want to be able to fetch the id, so do something like: story = db.get(story_key) author_id = story.author.key().id() I want to just get the id from the reference. I do not want to have to deference (therefore query the datastore) the ReferenceProperty value. From reading the documentation it says that the value of a ReferenceProperty is a Key Which leads me to think that I could just call .id() on the reference's value. But it also says: The ReferenceProperty model provides features for Key property values such as automatic dereferencing. I can't find anything that explains when this referencing takes place? Is it safe to call .id() on the ReferenceProperty's value? Can it be assumed that calling .id() will not cause a datastore lookup?

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• PHP does not store all variables in session

  - by Flurin Juvalta

  Dear all I'm assigning session variables by filling the $_SESSION - Array throughout my script. My problem is, that for some reason not all variables are available in the session. here is a shortened version of my code for explaining this issue: session_start(); print_r($_SESSION); $_SESSION['lang'] = 'de'; $_SESSION['location_id'] = 11; $_SESSION['region_id'] = 1; $_SESSION['userid'] = 'eccbc87e4b5ce2fe28308fd9f2a7baf3'; $_SESSION['hash'] = 'dce57f1e3bc6fba32afab93b0c38b662'; print_r($_SESSION); first call prints something like this: Array ( ) Array ( [lang] => de [location_id] => 11 [region_id] => 1 [userid] => eccbc87e4b5ce2fe28308fd9f2a7baf3 [hash] => dce57f1e3bc6fba32afab93b0c38b662 ) the second call prints: Array ( [lang] => de [location_id] => 11 [region_id] => 1 ) Array ( [lang] => de [location_id] => 11 [region_id] => 1 [userid] => eccbc87e4b5ce2fe28308fd9f2a7baf3 [hash] => dce57f1e3bc6fba32afab93b0c38b662 ) As you can see, the important login information is not stored in the session. Does anybody has an idea what could be wrong with my session? Thanks for your answers!

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