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  • How can I prevent javascript errors in my selenium tests from hanging my build system?

    - by lowellk
    We are having a problem with our selenium tests which run in IE on a virtual machine. Whenever there is a javascript error, a popup shows up and puts our system into a 'stuck' state - a user has to go clear that and restart the selenium test run. Is there a way to prevent the javascript error popup from putting the system into its stuck state? Would setting window.error be of any help here?

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  • Production ready alternative to Microsoft Doloto (Javascript minifier/prefetcher)?

    - by usr
    As you surely know Microsoft Doloto is tool which profiles you javascript code as it actually runs on the page and splits it in to two files: one file will be statically included in the footer of the page which contains stubs for all functions and loads the actual implementations (in file 2) in the background (under the assumption that only very litte javascript is needed on page load so you can defer downloading the rest). I found Doloto not to be production ready, it meanwhile has been canceled afaik. Is there a working alternative?

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  • How do I pass a javascript parameter to an asp.net MVCmodel from within a View?

    - by Josh
    Hi everyone! I am having an issue trying to access a list property on a model from within a javascript. My basic situation is this: I have an ArticleController and an ArticleViewModel. An Article has a number of properties, one of which is Text, which is just a string that contains the contents of the article. The ArticleViewModel contains a Pages property, which is just a List of Strings. When the ArticleViewModel constructor is called, I populate the Pages list by dividing up the article text based on some delimeters. I have a View which inherits the ArticleViewModel type. What I want to do is only display one page at a time, and then when the user clicks a page number (from a list at the bottom of the article), I want to use javascript to load that page into the #dynamicContent div. The problem: I can't seem to pass a parameter to the Model.Pages property from within javascript... Is this possible? I get an error stating, "Expression Expected" when I try what I have below. I don't want to have to worry about AJAX calls or anything like that since I already have the entire article... I just need a way to access each individual page from within the javascript function. Alternatively, if there is a better solution for "paginating" an article so that I can load each articlePage without having to refresh the entire html page, I would certainly be open to that as well. Any help would be much appreciated!! Thanks for your time! ArticleView Code: Script at the top of the view: function loadPage(pageNumber) { try { alert(pageNumber); $('#dynamicContent').html('<%=Model.Pages(' + pageNumber + ') %>'); } catch (e) { alert('in here'); alert(e.description); } } HTML for view: [...] <div id="articleBody"> <div id="dynamicContent"> <%=Model.Pages(0)%> </div> </div> [...] Page Links at bottom of page: [...] <div> <ul style="display:block"> <li style="display:inline"> <a href="#articleTitle" onclick="loadPage(0)"> 1 </a> </li> <li style="display:inline"> <a href="#articleTitle" onclick="loadPage(1)"> 2 </a> </li> </ul> </div>

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  • Will server-side JavaScript take off? Which implementation is most stable?

    - by Steve M
    Does anyone see server-side JavaScript taking off? There are a couple of implementations out there, but it all seems to be a bit of a stretch (as in, "doing it BECAUSE WE CAN" type of attitude). I'm curious to know if anyone actually writes JavaScript for the server-side and what their experiences with it have been to date. Also, which implementation is generally seen as the most stable?

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  • Take user input and write to file from javascript inside a pdf?

    - by dazedandconfused
    Is it possible to have a pdf file that asks a user a set of questions and then writes their answers to a file, then next time it is viewed loads those answers as default values? I know pdfs can include javascript and have figured out how to add javascript to a pdf with iText (http://itextpdf.com/) but don't know how to prompt for user input or write to a file from inside the pdf. Any help would be appreciated.

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  • jQuery Context Menu Plugin and Capturing Right-Click

    - by Ben Griswold
    I was thrilled to find Cory LaViska’s jQuery Context Menu Plugin a few months ago. In very little time, I was able to integrate the context menu with the jQuery Treeview.  I quickly had a really pretty user interface which took full advantage of limited real estate.  And guess what.  As promised, the plugin worked in Chrome, Safari 3, IE 6/7/8, Firefox 2/3 and Opera 9.5.  Everything was perfect and I shipped to the Integration Environment. One thing kept bugging though – right clicks aren’t the standard in a web environment. Sure, when one hovers over the treeview node, the mouse changed from an arrow to a pointer, but without help text most users will certainly left-click rather than right. As I was already doubting the design decision, we did some Mac testing.  The context menu worked in Firefox but not Safari.  Damn.  That’s when I started digging into the Madness of Javascript Mouse Events.  Don’t tell, but it’s complicated.  About as close as one can get to capture the right-click mouse event on all major browsers on Windows and Mac is this: if (event.which == null) /* IE case */ button= (event.button < 2) ? "LEFT" : ((event.button == 4) ? "MIDDLE" : "RIGHT"); else /* All others */ button= (event.which < 2) ? "LEFT" : ((event.which == 2) ? "MIDDLE" : "RIGHT"); Yikes.  The content menu code was simply checking if event.button == 2.  No problem.  Cory offers a jQuery Right Click Plugin which I’m sure works for windows but probably not the Mac either.  (Please note I haven’t verified this.) Anyway, I decided to address my UI design concern and the Safari Mac issue in one swoop.  I decided to make the context menu respond to any mouse click event.  This didn’t take much – especially after seeing how Bill Beckelman updated the library to recognize the left click. First, I added an AnyClick option to the library defaults: // Any click may trigger the dropdown and that's okay // See Javascript Madness: Mouse Events – http: //unixpapa.com/js/mouse.html if (o.anyClick == undefined) o.anyClick = false; And then I trigger the context menu dropdown based on the following conditional: if (evt.button == 2 || o.anyClick) { Nothing tricky about that, right?  Finally, I updated my menu setup to include the AnyClick value, if true: $('.member').contextMenu({ menu: 'memberContextMenu', anyClick: true },             function (action, el, pos) {                 … Now the context menu works in “all” environments if you left, right or even middle click.  Download jQuery Context Menu Plugin for Any Click *Opera 9.5 has an option to allow scripts to detect right-clicks, but it is disabled by default. Furthermore, Opera still doesn’t allow JavaScript to disable the browser’s default context menu which causes a usability conflict.

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  • What's new in ASP.Net 4.5 and VS 2012 - part 2

    - by nikolaosk
    This is the second post in a series of posts titled "What's new in ASP.Net 4.5 and VS 2012".You can have a look at the first post in this series, here. Please find all my posts regarding VS 2012, here. In this post I will be looking into the various new features available in ASP.Net 4.5 and VS 2012.I will be looking into the enhancements in the HTML Editor,CSS Editor and Javascript Editor.In order to follow along this post you must have Visual Studio 2012 and .Net Framework 4.5 installed in your machine.Download and install VS 2012 using this link.My machine runs on Windows 8 and Visual Studio 2012 works just fine.I will work fine in Windows 7 as well so do not worry if you do not have the latest Microsoft operating system.1) Launch VS 2012 and create a new Web Forms application by going to File - >New Web Site - > ASP.Net Web Forms Site.2) Choose an appropriate name for your web site.3) I would like to point out the new enhancements in the CSS editor in VS 2012. In the Solution Explorer in the Content folder and open the Site.cssThen when I try to change the background-color property of the html element, I get a brand new handy color-picker. Have a look at the picture below  Please note that the color-picker shows all the colors that have been used in this website. Then you can expand the color-picker by clicking on the arrows. Opacity is also supported. Have a look at the picture below4) There are also mobile styles in the Site.css .These are based on media queries.Please have a look at another post of mine on CSS3 media queries. Have a look at the picture below In this case when the maximum width of the screen is less than 850px there will be a new layout that will be dictated by these new rules. Also CSS snippets are supported. Have a look at the picture below I am writing a new CSS rule for an image element. I write the property transform and hit tab and then I have cross-browser CSS handling all of the major vendors.Then I simply add the value rotate and it is applied to all the cross browser options.Have a look at the picture below.  I am sure you realise how productive you can become with all these CSS snippets. 5) Now let's have a look at the new HTML editor enhancements in VS 2012You can drag and drop a GridView web server control from the Toolbox in the Site.master file.You will see a smart tag (that was only available in the Design View) that you can expand and add fields, format the web server control.Have a look at the picture below 6) We also have available code snippets. I type <video and then press tab twice.By doing that I have the rest of the HTML 5 markup completed.Have a look at the picture below 7) I have new support for the input tag including all the HTML 5 types and all the new accessibility features.Have a look at the picture below   8) Another interesting feature is the new Intellisense capabilities. When I change the DocType to 4.01 and the type <audio>,<video> HTML 5 tags, Intellisense does not recognise them and add squiggly lines.Have a look at the picture below All these features support ASP.Net Web forms, ASP.Net MVC applications and Web Pages. 9) Finally I would like to show you the enhanced support that we have for Javascript in VS 2012. I have full Intellisense support and code snippets support.I create a sample javascript file. I type If and press tab. I type while and press tab.I type for and press tab.In all three cases code snippet support kicks in and completes the code stack. Have a look at the picture below We also have full Intellisense support.Have a look at the picture below I am creating a simple function and then type some sort of XML like comments for the input parameters. Have a look at the picture below. Then when I call this function, Intellisense has picked up the XML comments and shows the variables data types.Have a look at the picture below Hope it helps!!!

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  • Restricting Input in HTML Textboxes to Numeric Values

    - by Rick Strahl
    Ok, here’s a fairly basic one – how to force a textbox to accept only numeric input. Somebody asked me this today on a support call so I did a few quick lookups online and found the solutions listed rather unsatisfying. The main problem with most of the examples I could dig up was that they only include numeric values, but that provides a rather lame user experience. You need to still allow basic operational keys for a textbox – navigation keys, backspace and delete, tab/shift tab and the Enter key - to work or else the textbox will feel very different than a standard text box. Yes there are plug-ins that allow masked input easily enough but most are fixed width which is difficult to do with plain number input. So I took a few minutes to write a small reusable plug-in that handles this scenario. Imagine you have a couple of textboxes on a form like this: <div class="containercontent"> <div class="label">Enter a number:</div> <input type="text" name="txtNumber1" id="txtNumber1" value="" class="numberinput" /> <div class="label">Enter a number:</div> <input type="text" name="txtNumber2" id="txtNumber2" value="" class="numberinput" /> </div> and you want to restrict input to numbers. Here’s a small .forceNumeric() jQuery plug-in that does what I like to see in this case: [Updated thanks to Elijah Manor for a couple of small tweaks for additional keys to check for] <script type="text/javascript"> $(document).ready(function () { $(".numberinput").forceNumeric(); }); // forceNumeric() plug-in implementation jQuery.fn.forceNumeric = function () { return this.each(function () { $(this).keydown(function (e) { var key = e.which || e.keyCode; if (!e.shiftKey && !e.altKey && !e.ctrlKey && // numbers key >= 48 && key <= 57 || // Numeric keypad key >= 96 && key <= 105 || // comma, period and minus key == 190 || key == 188 || key == 109 || // Backspace and Tab and Enter key == 8 || key == 9 || key == 13 || // Home and End key == 35 || key == 36 || // left and right arrows key == 37 || key == 39 || // Del and Ins key == 46 || key == 45) return true; return false; }); }); } </script> With the plug-in in place in your page or an external .js file you can now simply use a selector to apply it: $(".numberinput").forceNumeric(); The plug-in basically goes through each selected element and hooks up a keydown() event handler. When a key is pressed the handler is fired and the keyCode of the event object is sent. Recall that jQuery normalizes the JavaScript Event object between browsers. The code basically white-lists a few key codes and rejects all others. It returns true to indicate the keypress is to go through or false to eat the keystroke and not process it which effectively removes it. Simple and low tech, and it works without too much change of typical text box behavior.© Rick Strahl, West Wind Technologies, 2005-2011Posted in JavaScript  jQuery  HTML  

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  • Scripting Language Sessions at Oracle OpenWorld and MySQL Connect, 2012

    - by cj
    This posts highlights some great scripting language sessions coming up at the Oracle OpenWorld and MySQL Connect conferences. These events are happening in San Francisco from the end of September. You can search for other interesting conference sessions in the Content Catalog. Also check out what is happening at JavaOne in that event's Content Catalog (I haven't included sessions from it in this post.) To find the timeslots and locations of each session, click their respective link and check the "Session Schedule" box on the top right. GEN8431 - General Session: What’s New in Oracle Database Application Development This general session takes a look at what’s been new in the last year in Oracle Database application development tools using the latest generation of database technology. Topics range from Oracle SQL Developer and Oracle Application Express to Java and PHP. (Thomas Kyte - Architect, Oracle) BOF9858 - Meet the Developers of Database Access Services (OCI, ODBC, DRCP, PHP, Python) This session is your opportunity to meet in person the Oracle developers who have built Oracle Database access tools and products such as the Oracle Call Interface (OCI), Oracle C++ Call Interface (OCCI), and Open Database Connectivity (ODBC) drivers; Transparent Application Failover (TAF); Oracle Database Instant Client; Database Resident Connection Pool (DRCP); Oracle Net Services, and so on. The team also works with those who develop the PHP, Ruby, Python, and Perl adapters for Oracle Database. Come discuss with them the features you like, your pains, and new product enhancements in the latest database technology. CON8506 - Syndication and Consolidation: Oracle Database Driver for MySQL Applications This technical session presents a new Oracle Database driver that enables you to run MySQL applications (written in PHP, Perl, C, C++, and so on) against Oracle Database with almost no code change. Use cases for such a driver include application syndication such as interoperability across a relationship database management system, application migration, and database consolidation. In addition, the session covers enhancements in database technology that enable and simplify the migration of third-party databases and applications to and consolidation with Oracle Database. Attend this session to learn more and see a live demo. (Srinath Krishnaswamy - Director, Software Development, Oracle. Kuassi Mensah - Director Product Management, Oracle. Mohammad Lari - Principal Technical Staff, Oracle ) CON9167 - Current State of PHP and MySQL Together, PHP and MySQL power large parts of the Web. The developers of both technologies continue to enhance their software to ensure that developers can be satisfied despite all their changing and growing needs. This session presents an overview of changes in PHP 5.4, which was released earlier this year and shows you various new MySQL-related features available for PHP, from transparent client-side caching to direct support for scaling and high-availability needs. (Johannes Schlüter - SoftwareDeveloper, Oracle) CON8983 - Sharding with PHP and MySQL In deploying MySQL, scale-out techniques can be used to scale out reads, but for scaling out writes, other techniques have to be used. To distribute writes over a cluster, it is necessary to shard the database and store the shards on separate servers. This session provides a brief introduction to traditional MySQL scale-out techniques in preparation for a discussion on the different sharding techniques that can be used with MySQL server and how they can be implemented with PHP. You will learn about static and dynamic sharding schemes, their advantages and drawbacks, techniques for locating and moving shards, and techniques for resharding. (Mats Kindahl - Senior Principal Software Developer, Oracle) CON9268 - Developing Python Applications with MySQL Utilities and MySQL Connector/Python This session discusses MySQL Connector/Python and the MySQL Utilities component of MySQL Workbench and explains how to write MySQL applications in Python. It includes in-depth explanations of the features of MySQL Connector/Python and the MySQL Utilities library, along with example code to illustrate the concepts. Those interested in learning how to expand or build their own utilities and connector features will benefit from the tips and tricks from the experts. This session also provides an opportunity to meet directly with the engineers and provide feedback on your issues and priorities. You can learn what exists today and influence future developments. (Geert Vanderkelen - Software Developer, Oracle) BOF9141 - MySQL Utilities and MySQL Connector/Python: Python Developers, Unite! Come to this lively discussion of the MySQL Utilities component of MySQL Workbench and MySQL Connector/Python. It includes in-depth explanations of the features and dives into the code for those interested in learning how to expand or build their own utilities and connector features. This is an audience-driven session, so put on your best Python shirt and let’s talk about MySQL Utilities and MySQL Connector/Python. (Geert Vanderkelen - Software Developer, Oracle. Charles Bell - Senior Software Developer, Oracle) CON3290 - Integrating Oracle Database with a Social Network Facebook, Flickr, YouTube, Google Maps. There are many social network sites, each with their own APIs for sharing data with them. Most developers do not realize that Oracle Database has base tools for communicating with these sites, enabling all manner of information, including multimedia, to be passed back and forth between the sites. This technical presentation goes through the methods in PL/SQL for connecting to, and then sending and retrieving, all types of data between these sites. (Marcelle Kratochvil - CTO, Piction) CON3291 - Storing and Tuning Unstructured Data and Multimedia in Oracle Database Database administrators need to learn new skills and techniques when the decision is made in their organization to let Oracle Database manage its unstructured data. They will face new scalability challenges. A single row in a table can become larger than a whole database. This presentation covers the techniques a DBA needs for managing the large volume of data in a standard Oracle Database instance. (Marcelle Kratochvil - CTO, Piction) CON3292 - Using PHP, Perl, Visual Basic, Ruby, and Python for Multimedia in Oracle Database These five programming languages are just some of the most popular ones in use at the moment in the marketplace. This presentation details how you can use them to access and retrieve multimedia from Oracle Database. It covers programming techniques and methods for achieving faster development against Oracle Database. (Marcelle Kratochvil - CTO, Piction) UGF5181 - Building Real-World Oracle DBA Tools in Perl Perl is not normally associated with building mission-critical application or DBA tools. Learn why Perl could be a good choice for building your next killer DBA app. This session draws on real-world experience of building DBA tools in Perl, showing the framework and architecture needed to deal with portability, efficiency, and maintainability. Topics include Perl frameworks; Which Comprehensive Perl Archive Network (CPAN) modules are good to use; Perl and CPAN module licensing; Perl and Oracle connectivity; Compiling and deploying your app; An example of what is possible with Perl. (Arjen Visser - CEO & CTO, Dbvisit Software Limited) CON3153 - Perl: A DBA’s and Developer’s Best (Forgotten) Friend This session reintroduces Perl as a language of choice for many solutions for DBAs and developers. Discover what makes Perl so successful and why it is so versatile in our day-to-day lives. Perl can automate all those manual tasks and is truly platform-independent. Perl may not be in the limelight the way other languages are, but it is a remarkable language, it is still very current with ongoing development, and it has amazing online resources. Learn what makes Perl so great (including CPAN), get an introduction to Perl language syntax, find out what you can use Perl for, hear how Oracle uses Perl, discover the best way to learn Perl, and take away a small Perl project challenge. (Arjen Visser - CEO & CTO, Dbvisit Software Limited) CON10332 - Oracle RightNow CX Cloud Service’s Connect PHP API: Intro, What’s New, and Roadmap Connect PHP is a public API that enables developers to build solutions with the Oracle RightNow CX Cloud Service platform. This API is used primarily by developers working within the Oracle RightNow Customer Portal Cloud Service framework who are looking to gain access to data and services hosted by the Oracle RightNow CX Cloud Service platform through a backward-compatible API. Connect for PHP leverages the same data model and services as the Connect Web Services for SOAP API. Come to this session to get an introduction and learn what’s new and what’s coming up. (Mark Rhoads - Senior Principal Applications Engineer, Oracle. Mark Ericson - Sr. Principle Product Manager, Oracle) CON10330 - Oracle RightNow CX Cloud Service APIs and Frameworks Overview Oracle RightNow CX Cloud Service APIs are available in the following areas: desktop UI, Web services, customer portal, PHP, and knowledge. These frameworks provide access to Oracle RightNow CX Cloud Service’s Connect Common Object Model and custom objects. This session provides a broad overview of capabilities in all these areas. (Mark Ericson - Sr. Principle Product Manager, Oracle)

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  • Prefilling an SMS on Mobile Devices with the sms: Uri Scheme

    - by Rick Strahl
    Popping up the native SMS app from a mobile HTML Web page is a nice feature that allows you to pre-fill info into a text for sending by a user of your mobile site. The syntax is a bit tricky due to some device inconsistencies (and quite a bit of wrong/incomplete info on the Web), but it's definitely something that's fairly easy to do.In one of my Mobile HTML Web apps I need to share a current location via SMS. While browsing around a page I want to select a geo location, then share it by texting it to somebody. Basically I want to pre-fill an SMS message with some text, but no name or number, which instead will be filled in by the user.What worksThe syntax that seems to work fairly consistently except for iOS is this:sms:phonenumber?body=messageFor iOS instead of the ? use a ';' (because Apple is always right, standards be damned, right?):sms:phonenumber;body=messageand that works to pop up a new SMS message on the mobile device. I've only marginally tested this with a few devices: an iPhone running iOS 6, an iPad running iOS 7, Windows Phone 8 and a Nexus S in the Android Emulator. All four devices managed to pop up the SMS with the data prefilled.You can use this in a link:<a href="sms:1-111-1111;body=I made it!">Send location via SMS</a>or you can set it on the window.location in JavaScript:window.location ="sms:1-111-1111;body=" + encodeURIComponent("I made it!");to make the window pop up directly from code. Notice that the content should be URL encoded - HTML links automatically encode, but when you assign the URL directly in code the text value should be encoded.Body onlyI suspect in most applications you won't know who to text, so you only want to fill the text body, not the number. That works as you'd expect by just leaving out the number - here's what the URLs look like in that case:sms:?body=messageFor iOS same thing except with the ;sms:;body=messageHere's an example of the code I use to set up the SMS:var ua = navigator.userAgent.toLowerCase(); var url; if (ua.indexOf("iphone") > -1 || ua.indexOf("ipad") > -1) url = "sms:;body=" + encodeURIComponent("I'm at " + mapUrl + " @ " + pos.Address); else url = "sms:?body=" + encodeURIComponent("I'm at " + mapUrl + " @ " + pos.Address); location.href = url;and that also works for all the devices mentioned above.It's pretty cool that URL schemes exist to access device functionality and the SMS one will come in pretty handy for a number of things. Now if only all of the URI schemes were a bit more consistent (damn you Apple!) across devices...© Rick Strahl, West Wind Technologies, 2005-2013Posted in IOS  JavaScript  HTML5   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Admin Panel like Custom Framework

    - by bhuvin
    I want to Create a Framework , like Admin panel , which can rule almost all the aspects of what is shown on the frontend. For an (most basic) example: If suppose the links which are to be shown in a navigation area is passed from the server, with the order and the url , etc. The whole aim is to save the time on the tedious tasks. You can just start creating menus and start assigning pages to it. Give a url, actual files which are to be rendered (in case of static files.), in case of dynamic files, giving the file accordingly. And all this is fully server side manageable using different portlets, sort of things. So basic Roadmap is having : Areas like: Header Area - Which can contain logos, links etc. Navigation Area - Which can contains links and submenus. Content Area - Now this is where the tricky part is that that it has zones like: left, center & right. It contains Order in which it has to be displayed. So, when someday we want to change the way the articles appear on the page, we can do so easily, without any deployments. Now these zones can have n number of internal elements, like the word cloud, or the advertisement area. Footer Area: Again similar as Header Area. Currently there is a preexisting custom framework, which uses XSLT files for pulling out data from the server side. And it has the above capabilities. For example: If there's a grid it will be having a <table> tag embedded in the XSLT file. Now whatever might be the source of the data, we serialize this as XML and give it to the XSLT file and the html is derived from this and is appended to the layer in a page. The problem with this approach is: The XSLT conversion is occurring on the server side, so the server is responsible for getting the data, running XSLT transform, and append the html generated to the layer div. So, according to me, firstly this isn't the server's concern to do so. Secondly for larger applications this might be slower. Debugging isn't possible for XSLT transformation. So, whenever we face problems with data its always a bit of a trial & error method. Maintaining it is a bit of an eerie job i.e. styling changes, and other stuff. Adding dynamic values. Like JavaScript can't actually be very easily used in this. Secondly, we can't use JQuery or any other libraries with this since this is all occurring on the server. For now what I have thought about is using Templating - Javascript - JSON combination in place of XSLT, this will be offloaded to the client and the rendering will take place accordingly. This could solve the above problems and also could add mobile support for the same. Only problem which I could think of is that: It is much work and adding new portlets on the go needs to be looked into. What could be the alternatives for this? What kind of problems are there with the JavaScript approach? What are the different ways to implement the same? Are there any existing frameworks for similar usage?

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  • What are practical guidelines for evaluating a language's "Turing Completeness"?

    - by AShelly
    I've read "what-is-turing-complete" and the wikipedia page, but I'm less interested in a formal proof than in the practical implications of being Turing Complete. What I'm actually trying to decide is if the toy language I've just designed could be used as a general-purpose language. I know I can prove it is if I can write a Turing machine with it. But I don't want to go through that exercise until I'm fairly certain of success. Is there a minimum set of features without which Turing Completeness is impossible? Is there a set of features which virtually guarantees completeness? (My guess is that conditional branching and a readable/writeable memory store will get me most of the way there) EDIT: I think I've gone off on a tangent by saying "Turing Complete". I'm trying to guess with reasonable confidence that a newly invented language with a certain feature set (or alternately, a VM with a certain instruction set) would be able to compute anything worth computing. I know proving you can building a Turing machine with it is one way, but not the only way. What I was hoping for was a set of guidelines like: "if it can do X,Y,and Z, it can probably do anything".

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  • How do you read a file line by line in your language of choice?

    - by Jon Ericson
    I got inspired to try out Haskell again based on a recent answer. My big block is that reading a file line by line (a task made simple in languages such as Perl) seems complicated in a functional language. How do you read a file line by line in your favorite language? So that we are comparing apples to other types of apples, please write a program that numbers the lines of the input file. So if your input is: Line the first. Next line. End of communication. The output would look like: 1 Line the first. 2 Next line. 3 End of communication. I will post my Haskell program as an example. Ken commented that this question does not specify how errors should be handled. I'm not overly concerned about it because: Most answers did the obvious thing and read from stdin and wrote to stdout. The nice thing is that it puts the onus on the user to redirect those streams the way they want. So if stdin is redirected from a non-existent file, the shell will take care of reporting the error, for instance. The question is more aimed at how a language does IO than how it handles exceptions. But if necessary error handling is missing in an answer, feel free to either edit the code to fix it or make a note in the comments.

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  • What is a Windows scripting language that: does not rely on .NET and offers the most OOP support and

    - by jJack
    What is a Windows scripting language that: does not rely on .NET and offers the most OOP support and has simplest deployment? It doesn't necessarily need to be a scripting language; It can be in the form of a compiled executable, however it needs to be self contained--only ONE file, no DLL's and it cannot be declared to "include" other files. I cannot rely on the user having any .NET installed and it needs to be able to run on Windows 7 64 bit. By "most OOP support", I basically mean anything that has better OOP support than VBScript. A little context: Everything I have done thus far is in VBScript and writes a bunch of data into an .html file, which in the end is to be viewed by Internet Explorer. It also zips up a bunch of directories and files. It heavily relies on accessing the registry, file-system, and WMI (I can probably do without accessing WMI though, as long as I have good registry access). I can bring myself to code in any language so long as it meets me ridonkulous requirements stated above. I look forward to some good answers from those more experienced than I.

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  • What programming language do you wish would quietly retire? [closed]

    - by Gregory Higley
    This is the inverse of the "What programming language do you wish would catch on?" question. I was a Delphi programmer for many years, and I still appreciate its power, but I dislike verbose programming languages. So I would love to see Pascal put out to pasture. The same goes for BASIC in any form, despite the fact that it's the language I cut my teeth on. When I look at cathedrals of beauty like Haskell and REBOL, BASIC just makes me cringe. (VB.NET is tolerable, but barely. It has a few nice language features I'd like to see moved to C#.) My dislike of Pascal and VB.NET is subjective. They are powerful languages, but I dislike their syntax esthetically. Try to explain your reasoning, if you can, even if it's just "I don't like its syntax." This question is not meant to be a flame war, argumentative, or hateful. It's meant to be a straightforward, honest discussion of programmers' dislikes.

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  • scheme vs common lisp: war stories

    - by SuperElectric
    There are no shortage of vague "Scheme vs Common Lisp" questions on StackOverflow, so I want to make this one more focused. The question is for people who have coded in both languages: While coding in Scheme, what specific elements of your Common Lisp coding experience did you miss most? Or, inversely, while coding in Common Lisp, what did you miss from coding in Scheme? I don't necessarily mean just language features. The following are all valid things to miss, as far as the question is concerned: Specific libraries. Specific features of development environments like SLIME, DrRacket, etc. Features of particular implementations, like Gambit's ability to write blocks of C code directly into your Scheme source. And of course, language features. Examples of the sort of answers I'm hoping for: "I was trying to implement X in Common Lisp, and if I had Scheme's first-class continuations, I totally would've just done Y, but instead I had to do Z, which was more of a pain." "Scripting the build process in Scheme project, got increasingly painful as my source tree grew and I linked in more and more C libraries. For my next project, I moved back to Common Lisp." "I have a large existing C++ codebase, and for me, being able to embed C++ calls directly in my Gambit Scheme code was totally worth any shortcomings that Scheme may have vs Common Lisp, even including lack of SWIG support." So, I'm hoping for war stories, rather than general sentiments like "Scheme is a simpler language" etc.

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  • Scheme vs Common Lisp: war stories

    - by SuperElectric
    There are no shortage of vague "Scheme vs Common Lisp" questions on both StackOverflow and on this site, so I want to make this one more focused. The question is for people who have coded in both languages: While coding in Scheme, what specific elements of your Common Lisp coding experience did you miss most? Or, inversely, while coding in Common Lisp, what did you miss from coding in Scheme? I don't necessarily mean just language features. The following are all valid things to miss, as far as the question is concerned: Specific libraries. Specific features of development environments like SLIME, DrRacket, etc. Features of particular implementations, like Gambit's ability to write blocks of C code directly into your Scheme source. And of course, language features. Examples of the sort of answers I'm hoping for: "I was trying to implement X in Common Lisp, and if I had Scheme's first-class continuations, I totally would've just done Y, but instead I had to do Z, which was more of a pain." "Scripting the build process in my Scheme project got increasingly painful as my source tree grew and I linked in more and more C libraries. For my next project, I moved back to Common Lisp." "I have a large existing C++ codebase, and for me, being able to embed C++ calls directly in my Gambit Scheme code was totally worth any shortcomings that Scheme may have vs Common Lisp, even including lack of SWIG support." So, I'm hoping for war stories, rather than general sentiments like "Scheme is a simpler language" etc.

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  • Changes in Language Punctuation [closed]

    - by Wes Miller
    More social curiosity than actual programming question... (I got shot for posting this on Stack Overflow. They sent me here. At least i hope here is where they meant.) Based on the few responses I got before the content police ran me off Stack Overflow, I should note that I am legally blind and neatness and consistency in programming are my best friends. A thousand years ago when I took my first programming class (Fortran 66) and a mere 500 years ago when I tokk my first C and C++ classes, there were some pretty standard punctuation practices across languages. I saw them in Basic (shudder), PL/1, PL/AS, Rexx even Pascal. Ok, APL2 is not part of this discussion. Each language has its own peculiar punctuation. Pascal's periods, Fortran's comma separated do loops, almost everybody else's semicolons. As I learned it, each language also has KEYWORDS (if, for, do, while, until, etc.) which are set off by whitespace (or the left margin) if, etc. Each language has function, subroutines of whatever they're called. Some built-in some user coded. They were set off by function_name( parameters );. As in sqrt( x ) or rand( y ); Lately, there seems to be a new set of punctuation rules. Especially in c++ where initializers get glued onto the end of variable declarations int x(0); or auto_ptr p(new gizmo); This usually, briefly fools me into thinking someone is declaring a function prototype or using a function as a integer. Then "if" and 'for' seems to have grown parens; if(true) for(;;), etc. Since when did keywords become functions. I realize some people think they ARE functions with iterators as parameters. But if "for" is a function, where did the arg separating commas go? And finally, functions seem to have shed their parens; sqrt (2) select (...) I know, I koow, loosening whitespace rules is good. Keep reading. Question: when did the old ways disappear and this new way come into vogue? Does anyone besides me find it irritating to read and that the information that the placement of punctuation used to convey is gone? I know full well that K&R put the { at the end of the "if" or "for" to save a byte here and there. Can't use that excuse here. Space as an excuse for loss of readability died as HDD space soared past 100 MiB. Your thoughts are solicited. If there is a good reason to do this, I'll gladly learn it and maybe in another 50 years I'll get used to it. Of course it's good that compilers recognize these (IMHO) typos and keep right on going, but just because you CAN code it that way doesn't mean you HAVE to, right?

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  • Locale variables have no effect in remote shell (perl: warning: Setting locale failed.)

    - by Janning
    I have a fresh ubuntu 12.04 installation. When i connect to my remote server i got errors like this: ~$ ssh example.com sudo aptitude upgrade ... Traceback (most recent call last): File "/usr/bin/apt-listchanges", line 33, in <module> from ALChacks import * File "/usr/share/apt-listchanges/ALChacks.py", line 32, in <module> sys.stderr.write(_("Can't set locale; make sure $LC_* and $LANG are correct!\n")) NameError: name '_' is not defined perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = (unset), LC_TIME = "de_DE.UTF-8", LC_MONETARY = "de_DE.UTF-8", LC_ADDRESS = "de_DE.UTF-8", LC_TELEPHONE = "de_DE.UTF-8", LC_NAME = "de_DE.UTF-8", LC_MEASUREMENT = "de_DE.UTF-8", LC_IDENTIFICATION = "de_DE.UTF-8", LC_NUMERIC = "de_DE.UTF-8", LC_PAPER = "de_DE.UTF-8", LANG = "en_US.UTF-8" are supported and installed on your system. perl: warning: Falling back to the standard locale ("C"). locale: Cannot set LC_ALL to default locale: No such file or directory No packages will be installed, upgraded, or removed. 0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B of archives. After unpacking 0 B will be used. ... I don't have this problem when i connect from an older ubuntu installation. This is output from my ubuntu 12.04 installation, LANG and LANGUAGE are set $ locale LANG=de_DE.UTF-8 LANGUAGE=de_DE:en_GB:en LC_CTYPE="de_DE.UTF-8" LC_NUMERIC=de_DE.UTF-8 LC_TIME=de_DE.UTF-8 LC_COLLATE="de_DE.UTF-8" LC_MONETARY=de_DE.UTF-8 LC_MESSAGES="de_DE.UTF-8" LC_PAPER=de_DE.UTF-8 LC_NAME=de_DE.UTF-8 LC_ADDRESS=de_DE.UTF-8 LC_TELEPHONE=de_DE.UTF-8 LC_MEASUREMENT=de_DE.UTF-8 LC_IDENTIFICATION=de_DE.UTF-8 LC_ALL= Does anybody know what has changed in ubuntu to get this error message on remote servers?

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  • Are Java's public fields just a tragic historical design flaw at this point?

    - by Avi Flax
    It seems to be Java orthodoxy at this point that one should basically never use public fields for object state. (I don't necessarily agree, but that's not relevant to my question.) Given that, would it be right to say that from where we are today, it's clear that Java's public fields were a mistake/flaw of the language design? Or is there a rational argument that they're a useful and important part of the language, even today? Thanks! Update: I know about the more elegant approaches, such as in C#, Python, Groovy, etc. I'm not directly looking for those examples. I'm really just wondering if there's still someone deep in a bunker, muttering about how wonderful public fields really are, and how the masses are all just sheep, etc. Update 2: Clearly static final public fields are the standard way to create public constants. I was referring more to using public fields for object state (even immutable state). I'm thinking that it does seem like a design flaw that one should use public fields for constants, but not for state… a language's rules should be enforced naturally, by syntax, not by guidelines.

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  • Classes as a compilation unit

    - by Yannbane
    If "compilation unit" is unclear, please refer to this. However, what I mean by it will be clear from the context. Edit: my language allows for multiple inheritance, unlike Java. I've started designing+developing my own programming language for educational, recreational, and potentially useful purposes. At first, I've decided to base it off Java. This implied that I would have all the code be written inside classes, and that code compiles to classes, which are loaded by the VM. However, I've excluded features such as interfaces and abstract classes, because I found no need for them. They seemed to be enforcing a paradigm, and I'd like my language not to do that. I wanted to keep the classes as the compilation unit though, because it seemed convenient to implement, familiar, and I just liked the idea. Then I noticed that I'm basically left with a glorified module system, where classes could be used either as "namespaces", providing constants and functions using the static directive, or as templates for objects that need to be instantiated ("actual" purpose of classes in other languages). Now I'm left wondering: what are the benefits of having classes as compilation units? (Also, any general commentary on my design would be much appreciated.)

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