On 2/22/2012 9:01 PM, Harvey S. Frey wrote: > Problem: I want to use an HTML page as an alternative to Windows > Explorer, so I can annotate, edit and sort files. BUT, Javascript won't > let me access any local files. > > Desired solution: Embedding perl scripts to let me, for example, run an > editor on a file. I suppose I could do it if I ran a local server, like > TomCat, but that gets to be too much of a kludge. > > Question: Can I use Mason to embed perl scripts in an HTML file, which I > can run locally, without a server?
Hi Harvey, It may help to understand the basic processes going on. When you wish to display a web site, first your browser sends a request for the URL of that page to the server. It receives back, from the server, the HTML, usually. The browser then scans that HTML and figures out what else it needs: CSS, images, and so on. It then requests these and renders them. The browser is just requesting and the server is just sending static files. It is the browser that is actually acting on them; converting a .gif image binary into colored pixels, using the HTML and CSS files to build the page layout, etc. In this sense the browser is acting like a server, taking raw data and serving up graphical content on your screen (or maybe textual content if it is lynx, spoken content if it is a screen reader, etc). On the client side, the dynamic functionality of a web page comes from Javascript, which is a language that the browser understands. The key here is that the browser runs the Javascript, not the server. The server is simply sending plain text files with the Javascript source code. On the server side, the role of Mason is to take raw data, in the form of the request URL and various files, and turn that into HTML. The browser has no idea if the HTML it got from the server was originally a static file, some programming in PHP, Perl / Mason, or server side Java from something like Tomcat; and it doesn't care. All it needs is the HTML file - how that file is produced by the server is not relevant. In the case of Java, there are two modes: server side and client side. Server side runs in an application server, like Tomcat, and client side runs in a plug-in on the browser like the Sun Java plug-in. Javascript is similar, except that it is usually compiled into the browser and does not need a plug-in. Interestingly, it is possible for a Javascript application on the client to make requests to a Javascript application server. Neither Javascript engine would know it was communication with Javascript at the other end, and neither needs to know. Basically, what you are describing in your question is the ability to run Mason the same way you run Javascript - in the browser. The traditional model is that Javascript runs in the browser and Perl / Mason runs on the server. That is the underlying problem. Your browser is able to request files from the local filesystem, without the need for a true server, however, the windows filesystem is not normally capable of running applications in this manner. 1) The first solution is to get the browser to run Perl natively. This would likely be as a plug-in, the same way as Java. There have been attempts at this in the past. Since Perl was not written with this application in mind, adapting Perl to have a proper security model is challenging. http://docstore.mik.ua/orelly/perl3/tk/ch22_02.htm http://www.perlmonks.org/?node_id=514661 2) Without monkeying around with your browser, you could, as Jonathan suggested, run a server on your local computer that your browser makes requests to. There are a lot of lightweight servers, plus Apache installs and runs nicely as a service, if you do not mind its fairly large footprint. 3) It may be possible to use the browser's native file access to do as you wish, but you would have to set up a file system driver so that when you access a certain directory, it runs a program. In this case, that program would be your Mason handler, that is normally handled by the web server (see app.psgi in Jonathan's tutorial). http://en.wikipedia.org/wiki/Installable_File_System http://dokan-dev.net/en/ You would need Perl on your system. Look into Strawberry Perl. You would need to install all the Perl modules that Mason needs and some of them have an XS component for speed. If they provide a Pure Perl version, it could work, but would be slower. Moose is already pretty slow and this model is acting like a CGI request so you would not get the benefits of something like FastCGI or mod_perl. A compiler is not included on windows by default, but if you can install one, you should be able to build the XS modules. 4) In fact, Javascript is an environment agnostic language. Historically, for security reasons, in the browser it has been heavily sandboxed. But, with HTML5, you can now access local files with the File APIs. W3C specification for File APIs: http://www.w3.org/TR/file-upload/ Example of how to use it: http://www.html5rocks.com/en/tutorials/file/dndfiles/ So, generally, doing what you wish is a lot of work, unless you choose option #4, in which case, this is no longer a Mason question. Cheers. Paul Wallingford ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Mason-users mailing list Mason-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mason-users
