I'm building an app in ASP.NET that will store some pictures of objects. The pictures will be uploaded by suppliers and downloaded by subscribers. In between, they will have to be edited before becoming available to subscribers.
The editing involves creating a cropping path tightly around the object in the picture, in which some advanced desktop image software will have to be used I suppose.
My problem is in exchanging pictures between my ASP.NET app and the desktop software in a manner that is easy and transparent for the user.
I've done some thinking and I've come up with:
- Manually downloading and uploading the image (Not much user friendly...)
- An image editing program that can upload to a web service (Haven't found yet...)
- Develop a plug-in for an image editing program (Too advanced...)
I'd appreciate any suggestions you may have, thank you!
It sounds like you need some automation to move files between the web server and a file share. I am assuming that the number of images that need to be processed is pretty large, because if it's not, then the overhead of downloading/re-uploading each would not be that much.
So do the following:
1) Create an API for your web app that lists files that are available, or new files since some date/time, or files that have been marked as "new". The API should probably also allow marking a status on them (so you can tell it when you've finishing pulling something down, and it won't be offered again) if you don't want to trust date/time as an indicator of it being new.
2) Write an app (non-web) that runs on a schedule and uses this API to automatically download files to a shared filesystem area in your local network, and marks them as "downloaded"
The app should also monitor these files (the ones it downloaded & saved to your local share) for changes, and if changed, upload them back to your web app. To do this you may need to keep a database of filenames and modification dates/times.
This shouldn't be too hard to write in whatever language you are using for your web (assume c# or vb). By "API" I just mean, a web page that provides a list in a standardized format (e.g. json) that you can parse with your automation application, and another page that allows posting the file back for re-upload.
I'm assuming that the web server is not your own, or generally, you can't simply have it save the file uploads directly to some area where your image editors can access them. Otherwise you could just do that.
Meanwhile I came out with another possible solution.
I'm thinking of having our own windows app on the editor's computers. This app will be associated with a custom extension. When an editor downloads a file (with this extension) for editing, it will be opened in our application which in turn will open the image in some editor program.
This app will be monitoring the files for changes, and in such case, it will upload these images.
Any thoughts on this?
Related
My Xamarin forms app required the user to perform a certain amount of configuration before it can be used. Additionally, the app can be run on multiple computers by the same user (There are valid business reasons for doing this.) What I would like to be able to do is backup the configuration of the app to a file that can then be used on another device to automatically configure the app on the new device in exactly the same way. This will prevent the users from re-entering all the configuration information on each device where they wish to run the app.
Something to keep in mind:
It needs to work on all supported Xamarin Forms platforms - UWP, Android, iOS and Mac.
The app itself does not required the device to have a network connection.
The file needs to be savable in a place where the user can access / copy it to another device (i.e. a USB drive, a network share etc.)
What I have tried:
I have tried using the FilePicker plug in but could not get it to save to anywhere outside the application. (A user trying to find the folder here would not be easy.) Saving anyplace else I received an Access Denied error.
I have tried using the System.IO namespace but encountered the same Access Denied error when saving the file to a someplace outside the application.
I guess my last resort would be to display the configuration information in a XF editor control or such or just copy it to the clipboard (if possible) and have the user manually save the data to a file outside of the application. Does anyone have any other suggestions on how this can be handled?
So after trying multiple things and looking at possible solutions, I could not find a way to easily do this. Instead I used the Xamarin Essentials clipboard function and copied the contents of the file into the clipboard. I then display a message to the user telling them to past the clipboard contents into a file. This seemed to be the best I could do for now.
I'm making a web app. Part of it includes the automatic generation of word documents (letters). Those documents need to be opened by the end user, then saved back to the server once they've finished editing.
I tried using webdav for this but the only browser I could actually launch word from (using active-x) was IE. I also found a plugin for firefox, but for Chrome I couldn't find a way that worked.
Next I thought about making the clients map a drive to webdav (or similar), then offering up the files as file://... links, but that only works if the webpage is on the local machine.
Before I resort to ditching word (the clients won't like this) and using CKEditor or TinyMCE, is there another way?
In short, I'd like to have links to a document on the page, which when clicked are opened in word, but the file should stay remote - and then when saving, it's the remote file that gets updated.
I've also looked at Zoho but it could be very expensive for this project, plus I don't think it can be white-labelled and also looks a bit old fashioned, UI wise.
Maybe Sharepoint can do what I need? Haven't looked at that much. Also thought of making a client app to run in the system tray and deal with things.
If there was a decent way of editing Word docs from within the browser with something like CKEditor/TinyMCE and once finished, conversion back to Word format actually worked 100%, that would suffice.
I'm open to totally fresh ideas if anyone has any...
Currently Chrome, Firefox and Safari support MS Office plugin. They can open and save documents directly to server. I have tested this with MS Office 2007 and MS Office 2007 just about a month ago.
Ideally, your users would be able to use Word natively. Is there any chance you could create an Office Add-In that hooks into the BeforeDocumentSave event, looks for some indicator that the file is associated with your application, and save the updated file to your server?
Saving to the server via the Word Add-In would probably need to include some unique identifier (in addition to file name), so you could overwrite the previous version server-side. Then, if you were using something like SignalR, you could trigger a refresh on the web page when the file was saved successfully (assuming they were still on that web page) on the server (via FileSystemWatcher).
Had same problem myself.
I solved it by setting up a webdav share on the server with digest authentication (SabreDAV), and tied it into the users table on my app backend.
In relation to the client end, I solved accessing this by creating a small java applet which uses the java Desktop class (getDesktop().open()) to open the file. You will need to make sure the path is handled right for the client machine type (Windows, OS X or Linux)
You will also need to get your end users to permanently mount or map the webdav share locally.
Using Classic ASP (stop tutting), I need to build an application that transfers high resolution photos from one server to another, around 360,000 including the thumbnails to be exact. The application will be called via a Windows schedule and will run as a background process.
What is the best way to achieve this, keeping performance in-mind? The last time I built a monster script like this was transferring and converting database tables for over one million rows, the application started really fast, but then after 25,000 records it went really, really slow! So I want to avoid this.
Obviously it will be a cross-domain transfer, so I was thinking about using an ASP/FTP component, and one-by-one, grab a file, send it, and record its success in a DB table so it knows what is has done so far.
Is it best to process one file at a time and refresh, so it doesn't abuse the server's resources, or should I process 1000 at a time, or more? I want it to be as quick as possible but without clogging up the server.
Any help/suggestions would be gratefully received.
I think is best to do one file at a time because if the connection goes down for a brief period of time you don't lost the files that you have already sent.
Even when you are using ASP Classic you can take advantage of .net for uploading the files using the FTP client classes in .net and avoid purchasing/installing a third party component. Surely .net is already installed on the server.
My process will look like this:
Upload 1 file using FTP (better performance)
If successful call an ASP page that records the action in the remote DB
Wait a second and retry up to 3 times if error uploading
Proceed to next file
If the process is clogging the server, you can put a brief pause between each upload.
i have something like that running in Classic ASP, it handles tenthousands of images without problem.
On the server that houses the images I run a (vbs)script that for each image
Makes a text-file with metadata
Makes a thumbnail and a mid-sized image copy on the second (web)server
The script runs continuously and only checks per folder and file if the files are present on the webserver and if not creates them, No need for a DB.
Between every check It sleeps a second. Like that the load on the server is only 2%. I use iPhoto in command-line modus to extract the metadata and images but you could use a library for that.
So these three files are stored on the webserver in a copy of the mapstructure from the first server but without de full-sized images.
On the webserver you only need to be able to browse the thumbnails and visualize the metadata and mid-size images.
If the user needs the full-size image he clicks the mid-sized which has as url the file on the first server.
Upload all the files via FTP
Create a CSV file with all your data
Pull it into the DB in one go
The amount of network handshake over 360,000 individual transactions would be the bottleneck.
Before I attempt to program the following function myself, I wonder if something already exists.
What I would like to do is click an edit link on my website for a given document, and have that document launch in the native editor on my local machine (via a temporary file mechanism).
When I save the document in the native editor, the document is HTTP PUT back to the website. This can be accomplished by watching the file for writes, or watching the editor process for exit.
This way I can more easily edit documents on the web (instead of going through the download / edit / upload cycle).
My design would work as follows:
Register .webedit files on the local machine.
When a .webedit file is downloaded, launch webedit.exe with the file.
The file contains a URL (http://server/document) which is checked against a security database to ensure we're only opening allowed URLs.
The URL is downloaded to a temporary location.
The temporary file is launched in the native editor.
The file is watched for changes, and uploaded (HTTP PUT) on change detection (or when the editor is closed, if it's not a single-instance multiple-document editor).
Lots of FTP / SCP GUIs have this type of functionality, but I have not been able to find it for the web in general, or a shared library that allows you to plug in to this function.
Has anyone seen a program that does this?
SharePoint works like this.
It's great for managing shared documents in corporate environments.
Users can even checkout/checkin documents & the features are very extensible..you can customize pretty much anything if you know how.
Edit:
Since you're on Linux..i've heard that Alfreco is a great alternative.
I've never used it, but I know a couple organizations using it instead of SharePoint.
It integrates with Microsoft Office as well.
Also, it will definitely be cheaper.
I have a .jpg file which represents the current image from a webcam. User's will be downloading this file at an interval of once a second. Because there could be dozens of users reading it, this could be dozens of times a second (which is normal for any web server).
Problem is, this image is updated by a 3rd party application also once a second which "spiders" my local networks webcam portal image. This is so we can build our webcams into our current administration panel.
The problem I am already finding is ASP.net sometimes gets an error it can not access the file because it is open for write permissions by the bot. Likewise, the bot can not access it because IIS is feeding it to the user.
The bot uses io.streamwriter to save the data to the file, and my script uses Response.WriteFile to send the file to the script. (I need to use an actual ASP.net page with a JPG content-type that feeds the file to make sure only users with a active session can view the JPG).
My question is what is the best practices for this? I know why it's happening but what is the best resolution for this? Would storing as a BLOB in a database maybe be smarter since databases are created for concurrent read/writing already? Is there an easier way of doing this with a file I have not thought of yet?
Thanks in advance,
Anthony Greco
Using a BLOB will work if the readers use SNAPSHOT isolation model (SQL Server 2005 and up). See Download and Upload images from SQL Server via ASP.Net MVC for how to stream an image from a BLOB, and see Understanding Row Versioning-Based Isolation Levels for a lecture on SNAPSHOT.
But using a BLOB may be overkill, you could get away with something much simpler. For instance, if you only have one ASP.Net process, then you could have a global volatile variable for the current file name. The writer writes the JPG into a new file, and then updates the global 'current' file name with an Interlocked.CompareExchange operation (it has to be Compare because a newer writer might actually finish faster, outrun a previous writer, and you want to preserve the latest update). There are still some issues left to solve (find out the file name at startup, clean up old files etc) but they are all fairly ease to solve.
If you have a farm of servers, or multiple ASP.Net processes serving the site, then things could get complicated. I would still do a rotating file name and do a try-and-error approach (try to respond with newest file, fall back to previous older one if conflict is detected).
You could get the bot to write the data to a different filename and then do a delete and rename to the filename being served by ASP.Net. This should reduce the file lock time down to the time for a delete and rename to occur. To clarify:
ASP.Net serving image from "webcam.jpg"
bot writes image data to "temp.jpg"
when last image byte written, bot deletes "webcam.jpg" and renames "temp.jpg" to "webcam.jpg"
ASP.Net should check "webcam.jpg" exists, if not wait 10ms (or suitable small increment) and check again.