How to handle uploading html content to an AppEngine application? - html

I would like to allow my users to upload HTML content to my AppEngine web app. However if I am using the Blobstore to upload all the files (HTML files, css files, images etc.) this causes a problem as all the links to other files (pages, resources) will not work.
I see two possibilities, but both of them are not very pretty and I would like to avoid using them:
Go over all the links in the html files and change them to the relevant blob key.
Save a mapping between a file and a blob key, catch all the redirections and serve the blobs (could cause problems with same name files).
How can I solve this elegantly without having to go over and change my user's files?

Because app engine is running your content on multiple servers, you are not able to write to the filesystem. What you could do is ask them to upload a zip file containing their html, css, js, images,... The zipfile module from python is available in appengine, so you can unzip these files, and store them individually. This way, you know the directory structure of the zip. This allows you to create a mapping of relative paths to the content in the blobstore. I don't have enough experience with zipfile to write a full example here, I hope someone more experienced can edit my answer, or create a new one with an example.

Saving a mapping is the best option here. You'll need to identify a group of files in some way, since multiple users may upload a file with the same name, then associate unique pathnames with each file in that group. You can use key names to make it a simple datastore get to find the blob associated with a given path. No redirects are required - just use the standard Blobstore serving approach of setting the blobstore header to have App Engine serve the blob to the user.
Another option is to upload a zip, as Frederik suggests. There's no need to unpack and store the files individually, though - you can serve them directly out of the zip in blobstore, as this demo app does.

Related

Flutter render downloaded html

I have an elearning APP in Flutter, which can render html files stored online. Now I want to download these files to assets, so they may be accessed offline. For this, I will download a zipped file with the entire html's folder and unzip it.
The problem is the html has many subfolders with it's own assets, which I would have to declare in the pubsp.yaml in order to access, but these downloadable htmls are constantly being added (every new course has new files).
I see a few ways to solve the problem:
Somehow declare access to subfolders in the pubsp.yaml.
As far as I know, this cannot be done.
Update the folder access for the installed APP dynamically.
As far as I know, this cannot be done.
Read the html file without unziping it.
I don't know if this is doable (I'm using webview_flutter_plus to render) and weather it would allow access to files in folders inside the zip without declaring them in the .yaml.
Pre-load empty folders inside assets that would mimic the html folder structure, declare them in the .yaml and then unzip and read the htmls from these folders. I would create some 100 of them in order to accomodate a large number of course downloads.
I believe this method would work, but it seems very cumbersome and inelegant.
So my questions are:
Would any of methods 1-3 work and if so how?
Would method 4 work?
Is it possible to reference folders in the .yaml file without them existing? It would make method 4 far easier.
Is there any other way to accomplish this? I cannot change the language, since the APP is months along, but plugins are fair game.
Thanks in advance!

Store files in database with DBIC using Catalyst

I'm using Perl Catalyst framework to build an application that needs to store several files in a MySQL database (among other things). I want to store the name, path, extension, etc of the files to retrieve them later; because they are supposed to be accessible from the application (e.g: a PDF document uploaded for someone, must be available for download later). Can I do this? I found several ways to do it in PHP, but none for perl. Any ideas?
EDIT
I know I can access to some information using Catalyst::Request::Upload. I used this in the past for BLOB storage, but I dont't know how to get file information nor how to know where does catalyst store tmp files.
So, basically, the questions that arise when trying to this are:
How to know where are my files being stored once I submit them?
How to copy these files (which I assume go to a tmp folder somewhere) to a folder in my computer/server?
How to retrieve these files once I have them stored?
EDIT 2
I've checked again the documentation for Catalyst::Request::Upload (http://search.cpan.org/~jjnapiork/Catalyst-Runtime-5.90114/lib/Catalyst/Request/Upload.pm) and found out how to know where are my files being stored and how to copy them to a new non-tmp location. The only question that remains:
How do I generate a download link for these files??
The solution was pretty straight-forward.
First Make sure your 'tmp' folder is configured in the Catalyst app file (e.g: MyApp.pm).
Now, use Catalyst::Request::Upload to create the file object with the uploaded file. Sort of...
my $upload = $req->upload('input_field_name');
Now make sure you get all the data you want to store from the file. I, personally, got just the filename, MIME Type and size.
my $filename = $upload->filename;
my $size = $upload->size;
my $type = $upload->type;
Store into the database.
Now, create a folder within the public content of the page to copy the files to, and perform the copy like:
$upload->copy_to('path/to/the/public/folder');
To retrieve the files, just create a link with the base URL to the public folder and the filename you stored in the database.
Hope it helps someone... it was pretty obvious, though; but it cracked my head a little.

Swagger API Specification filenames

I'm trying to use Swagger to create API documentation for an API we're building and I've never used it before.
The documentation on Github says that the Resources Listing needs t be at /api-docs and the various resource files need to be at /api-docs/books etc.
This makes naming files and folders very tricky. I think they expect the files to have no file names, rather than having a folder called /api-docs it has to be an extension-less file, then you can't put the resources in an api-docs folder because you can't call the folder that, so they suggest using a folder called /listings.
This folder doesn't appear in the URL structure of your documentation though, it's kind of invisible because you set the baseURL in your resources to the proper path, but it looks like that has to be an absolute path, which is awkward if you want to have it on several servers (local and production).
Maybe I just don't get it but this all seems to be absolutely nuts.
So, I have 2 questions.....
1) Can I give my resource listing file and my resource files a .json extension? This would make sense as it's a JSON file.
2) Can I use a relative path to the resource listing file in the baseURL in my resource files?
Ideally, my file structure would be flatter, like this...
/api-docs
resources.json
books.json
films.json
Is Swagger flexible enough to do this?
It's an IIS server if that makes any difference (if the solution requires routing for example).
I was able to put model files into a folder under the web root and could reference them like this.
$ref: '/models/model.yml#/MyObject'
Relative paths also worked without a leading slash.
$ref: 'models/model.yml#/MyObject'
Inside the model.yml, I can reference other objects int eh same file like this
$ref: '#/MyObject2'.
However, I could only get the main swagger file to import model files. I could not get one model file to cross-reference another model file.
I was using a Tomcat web server but the principle will be the same.

Is there any way to fill in Sharepoint entries via parsing text file?

My workplace has a whole bunch of unannotated .zip files that need to be uploaded to the new file server (Windows). I've used perl to parse through through the excel files within the .zip files to create an annotation.txt file for each .zip file that contains information about the .zip file. I have 1000's of zip files and do not want to manually enter in information for each entry if there's a way to automate it. I am proficient in perl and mysql, and wondering if there is any way to utilize my skillsets to port this information into the Microsoft Sharepoint website.
Thank you in advance for any advice or suggestions.
There a many, many ways to meet your requirement.
You could write a event receiver to parse the files once uploaded and set metadata.
A better approach for your use case might be to write a .NET based console application and reference Microsoft.SharePoint.Client and then upload your files using the Client side object model (CSOM) and set the metadata during that process as outlined here: Upload a document to a SharePoint list from Client Side Object Model
There are also REST and ASMX webservices that you could call from a non .NET runtime process.
Plenty of options, pick the one that fits your needs and skills best.

Output reformatted text within a file included in a JSP

I have a few HTML files that I'd like to include via tags in my webapp.
Within some of the files, I have pseudo-dynamic code - specially formatted bits of text that, at runtime, I'd like to be resolved to their respective bits of data in a MySQL table.
For instance, the HTML file might include a line that says:
Welcome, [username].
I want this resolved to (via a logged-in user's data):
Welcome, user#domain.com.
This would be simple to do in a JSP file, but requirements dictate that the files will be created by people who know basic HTML, but not JSP. Simple text-tags like this should be easy enough for me to explain to them, however.
I have the code set up to do resolutions like that for strings, but can anyone think of a way to do it across files? I don't actually need to modify the file on disk - just load the content, modify it, and output it w/in the containing JSP file.
I've been playing around with trying to load the files into strings via the apache readFileToString, but I can't figure out how to load files from a specific folder within the webapp's content directory without hardcoding it in and having to worry about it breaking if I deploy to a different system in the future.
but I can't figure out how to load files from a specific folder within the webapp's content directory without hardcoding it in and having to worry about it breaking if I deploy to a different system in the future.
If those files are located in the webcontent, use ServletContext#getRealPath() to convert a relative web path to an absolute disk file system path. This works if the WAR is exploded in the appserver (most does it by default, only Weblogic doesn't do that by default, but this is configureable IIRC). Inside servlets you can obtain the ServletContext by the inherited getServletContext() method.
String relativeWebappURL = "/html/file.html";
String absoluteFilePath = getServletContext().getRealPath(relativeWebappURL);
File file = new File(absoluteFilePath);
// ...
Alternatively, you can put it in the classpath of the webapplication and make use of ClassLoader#getResource():
String relativeClasspathURL = "/html/file.html";
URL absoluteClasspathURL = Thread.currentThread().getContextClassLoader().getResource(relativeClasspathURL);
File file = new File(absoluteClasspathURL.toURI());
// ...
As to the complete picture, I question if you have ever considered an existing templating framework like Freemarker or Velocity to ease all the job?