On Wed, May 16, 2012 at 6:14 AM, Alan Hoffmeister <alanhoffmeis...@gmail.com > wrote:
> Tim that's a very good idea! > But how can I share the hash and the dimensions between the view > helper and the resizing route? > Well that depends on the nature of your code. Is it a framework like express, is it something else. If you're running the entire site in a single process then a single variable in the outer closure would be global enough. Just like I wrote in the example, my lookup tables are outside the helper and the http route handler. As long as it's in a common place they can both see in their closures, they will have access. > > -- > Att, > Alan Hoffmeister > > > 2012/5/15 Tim Caswell <t...@creationix.com>: > > btw, this code isn't perfect. For example, there is no reason to use the > > expensive md5 hash. It's not like the browser is sending you path, > width, > > and height and you need to re-hash them. Any random unique string would > be > > fine. Also the key variable would sufficient as well. Yes, the url > > contains the parameters, but they can't be modified to create a new > value. > > Only existing keys would be served. > > > > The important part is to create some unique key to embed in the url so > that > > later when the request comes in, you have a way to map it to the original > > resize command. The caching and batching pattern is described > > here http://nodebits.org/distilled-patterns > > > > > > On Tue, May 15, 2012 at 3:47 PM, Tim Caswell <t...@creationix.com> wrote: > >> > >> > >> > >> On Tue, May 15, 2012 at 2:46 PM, Alan Hoffmeister > >> <alanhoffmeis...@gmail.com> wrote: > >>> > >>> Hey guyz, of course I need to validate, I just don't want to expose > >>> the dimensions. > >> > >> > >> The thing is you have to expose the dimensions if the request coming > from > >> a browser includes the dimensions. > >> > >> If you want to emulate what php is doing, it's easy enough. Basically > >> this would be a template helper that registers a new route when found. > >> > >> // load the createHash function from the crypto module > >> var createHash = require('crypto').createHash; > >> > >> // Keep a history of registered routes > >> var resizes = {}; > >> // Store an index by hash for url routing > >> var hashes = {}; > >> // Register a new resize command, export this as a template helper. > >> function resize(path, width, height) { > >> var key = path + width + "x" + height; // convert args to a unique > >> string > >> if (resizes[key]) return resizes[key].url; // Check cache to see if > it's > >> already registered > >> var hash = createHash("md5").update(key).digest("hex"); // calculate > the > >> md5 hash of the key to hide the params > >> var entry = { > >> url: "/images/" + hash + ".png", > >> path: path, > >> width: width, > >> height: height > >> }; > >> // Store the object in the two tables. > >> resizes[key] = entry; > >> hashes[hash] = entry; > >> // return the url. > >> return entry.url; > >> } > >> > >> > >> Then later in your http request handler, add a route to handle these > >> requests. > >> > >> app.get("/images/:hash.png", function (req, res) { > >> var entry = hashes[req.params.hash]; > >> if (!entry) return doErrorHandling(); > >> resizeImage(entry, function (err, resizedPath) { > >> if (err) return doErrorHandling(); > >> }); > >> }); > >> > >> And here is some untested code that does caching and batching of the > async > >> resize requests > >> > >> function resizeImage(entry, callback) { > >> // Check if it's been resized already > >> if (entry.resizedPath) { > >> return callback(null, entry.resizedPath); > >> } > >> // Check if there is already a pending resize operation on this object > >> if (entry.resizeQueue) { > >> return entry.resizeQueue.push(callback); > >> } > >> entry.resizeQueue = [callback]; > >> doRealResize(entry.path, entry.width, entry.height, function (err, > >> resizedPath) { > >> if (err) return callback(err); > >> var callbacks = entry.resizeQueue; > >> delete entry.resizeQueue; > >> entry.resizedPath = resizedPath; > >> callbacks.forEach(function (callback) { > >> callback(null, resizedPath); > >> }); > >> }); > >> } > >> > >> function doRealResize(path, width, height, callback) { > >> // Do actual resize and return the final filename's filepath > >> } > >> > >>> -- > >>> Att, > >>> Alan Hoffmeister > >>> > >>> > >>> 2012/5/15 Duncan Gmail <duncananguswil...@gmail.com>: > >>> > You can POST the size as well as use GET. On the numbers, just > >>> > validate the input - you should be doing this anyway for all > inputted data, > >>> > in all languages. > >>> > > >>> > - MRdNk > >>> > > >>> > On 15 May 2012, at 15:21, Alan Hoffmeister < > alanhoffmeis...@gmail.com> > >>> > wrote: > >>> > > >>> >> Marc, that would work, but I'm concerned about security... What if > >>> >> someone access the url /images/100000/100000/avatar.jpg ? > >>> >> > >>> >> -- > >>> >> Att, > >>> >> Alan Hoffmeister > >>> >> > >>> >> > >>> >> 2012/5/15 Marc Deschamps <md.fle...@gmail.com>: > >>> >>> I've done something like this using express: > >>> >>> > >>> >>> app.get('/images/:width/:height/:filename', routes.images.resize); > >>> >>> > >>> >>> Work great, in html i can do: > >>> >>> > >>> >>> <img src="/images/70/70/avatar.jpg"/> > >>> >>> > >>> >>> -- > >>> >>> Job Board: http://jobs.nodejs.org/ > >>> >>> Posting guidelines: > >>> >>> > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > >>> >>> You received this message because you are subscribed to the Google > >>> >>> Groups "nodejs" group. > >>> >>> To post to this group, send email to nodejs@googlegroups.com > >>> >>> To unsubscribe from this group, send email to > >>> >>> nodejs+unsubscr...@googlegroups.com > >>> >>> For more options, visit this group at > >>> >>> http://groups.google.com/group/nodejs?hl=en?hl=en > >>> >> > >>> >> -- > >>> >> Job Board: http://jobs.nodejs.org/ > >>> >> Posting guidelines: > >>> >> https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > >>> >> You received this message because you are subscribed to the Google > >>> >> Groups "nodejs" group. > >>> >> To post to this group, send email to nodejs@googlegroups.com > >>> >> To unsubscribe from this group, send email to > >>> >> nodejs+unsubscr...@googlegroups.com > >>> >> For more options, visit this group at > >>> >> http://groups.google.com/group/nodejs?hl=en?hl=en > >>> > > >>> > -- > >>> > Job Board: http://jobs.nodejs.org/ > >>> > Posting guidelines: > >>> > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > >>> > You received this message because you are subscribed to the Google > >>> > Groups "nodejs" group. > >>> > To post to this group, send email to nodejs@googlegroups.com > >>> > To unsubscribe from this group, send email to > >>> > nodejs+unsubscr...@googlegroups.com > >>> > For more options, visit this group at > >>> > http://groups.google.com/group/nodejs?hl=en?hl=en > >>> > >>> -- > >>> Job Board: http://jobs.nodejs.org/ > >>> Posting guidelines: > >>> https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > >>> You received this message because you are subscribed to the Google > >>> Groups "nodejs" group. > >>> To post to this group, send email to nodejs@googlegroups.com > >>> To unsubscribe from this group, send email to > >>> nodejs+unsubscr...@googlegroups.com > >>> For more options, visit this group at > >>> http://groups.google.com/group/nodejs?hl=en?hl=en > >> > >> > > > > -- > > Job Board: http://jobs.nodejs.org/ > > Posting guidelines: > > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > > You received this message because you are subscribed to the Google > > Groups "nodejs" group. > > To post to this group, send email to nodejs@googlegroups.com > > To unsubscribe from this group, send email to > > nodejs+unsubscr...@googlegroups.com > > For more options, visit this group at > > http://groups.google.com/group/nodejs?hl=en?hl=en > > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to nodejs@googlegroups.com > To unsubscribe from this group, send email to > nodejs+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en > -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. 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