I would like to download a course and work offline on that course. How can I track my results?
I would like to record all my progress(slides that I viewed, quiz results, time for each content....), for example saving them on a file or a database, and then generate statements to send to an LRS when I'm online.
Someone could explain me how can I do that?
With TinCan statements (commonly including information about the student(actor) and then what they did, objectives, status etc) are being posted to a endpoint. Depending on how the content is written it may or may not failover to some alternative. If its a native application I would suspect you'll have limited ability to intercept these statements. If its a HTML course you may be able to locate where the content attempts to post these statements and re-direct those to local storage or some other sql/nosql option. Ultimately, it will depend on what content you're attempting to run, and what type of controls you'll have to attempt to. Based on what I know, the content itself would have to detect its 'offline' and store the statements until it is back online. Similar to this post - How tin-can-api works offline?
SCORM ultimately doesn't work like TinCan. LMS exposes a JavaScript API, and the HTML based content locates it in the DOM using JavaScript. Content then makes gets and set calls to it. The LMS is more responsible for committing this information to a server, or persisting the data in another fashion. This doesn't stop content developers from creating new and alternative ways to persist data if the LMS is not present. For this type of content its probably easier to intercept since you can be the LMS in this situation and expose that API for the content to use. In a offline situation you'd just have to manage the student attempts and then once online- sync them with your server.
Related
Ok basically i'm fetching data from website using curl and parsing the contents using CkHtmlToText.
My issue is how to fetch new data website is writing down.
For example website contents are as follow:
-test1
-test2
After 1 second contents are :
-test1
-test2
-test3
How to fetch only the next line website wrote down that i didnt get yet which is " test3".
Any ideas ? Thank you.
Language im using is : Visual c++
HTTP requests are stateless. You make a request, you get a result, then you make another completely independent request, you get another result, and so on. If the resource you are trying to access is changing over time, you need to make multiple requests, where each time you will get the full updated resource.
I imagine you may be describing a web page that automatically updates while you are looking at it (like a Twitter feed, for example). In that case, the response contains a script that allows the browser to fetch new data and inject it into the DOM. Unless you also plan to build the DOM and use a JavaScript engine (basically implementing a web browser) to run the script, this is probably not useful to you. Instead, you are better off finding an API that gives you data in a format that is easy to parse and get updates for. If this API is a REST API (built on HTTP), then you will still need to make independent requests to get updates.
Why this (hopefully) isn't a broad question:
I've been looking at the Django source code on syndication. I understand functionally what these feeds are and what they do but I'm not sure how the magic happens.
Actual question:
What is Django doing under the hood to send these changes out across the wire? Is Django just creating an object (like an XML file) the Client reads and not even using the network? What mechanism is employed to ensure users get those updates in a 'reasonable' amount of time - is it a combination of the browser (or some other software) knowing to go look for updates while Django diligently adds data to a file, or does Django do most of the work?
There's no magic, and Django does not do anything to even try to ensure clients get updates in any particular amount of time.
Feeds, like almost everything on the web, are an entirely pull-based mechanism. Feed readers are responsible for periodically requesting updates from the client.
To start off, I am extremely sorry if my question is not clear but I have very little knowledge about web services in general and the vast nature of varying available information has driven me crazy over the past few weeks. So please do bear with me.
Summary: I want to create a live score update app for android. (I haven't added android as a tag because I do know how to retrieve data from say twitter's JSON api.) However, like the twitter JSON api, I want to be able to add(POST maybe?) data to the Apache 7.0 service that I have running. I then want the app to be able to be able to retrieve this data that I have posted.
I had asked a more generic question earlier and I was told that I should look up some api's. I did that but I have still not been unable to make a break through.
So my questions is:
Is setting up an API on my local web service the correct way to do this?
If so, how can I setup an API that will return JSON objects to the Android app. Also, I would need to be able to constantly update this API with new data.
Additionally, would I also need to setup a database for all this?
Any links to well explained matter would be appreciated too.
Note: I would like to carry this out using a RESTful Web Service through Jersey and use JSON Objects during retrieval.
Again, I am sorry about my terrible knowledge with web services in general despite trying my best to research a lot. The best I could do was get my RESTful Web to respond to a GET with some pre-defined text that I had set in Eclipse.
Thanks.
If I understand you correctly, what you try to do is something like this:
There will be a match or multiple matches of some sort. Whenever a team/player scores someone (i.e. you) will use the app to update the score. People who previously subscribed to the match, will be notified and see the updated score.
Even though I'm not familiar with backends based on Java, the implementation should be fairly similar to other programming languages.
First of all a few words to REST in general. REST is generally needed, when you need to share information between multiple devices and or users. This seems to be the case here. To implement the REST you are going to need an API of some sorts. Within the web APIs are implemented by webservers answering to certain predefined HTTP Requests.
Thus setting up an API on a web server is the correct way.
Next a few words on databases. A database is generally needed, if you want to store information persistently. This might, or might not be what you are planning to do. If there are just going to be a few matches at the same time and you don't care about persistence of the data, you can use Java to store a collection of match objects in memory. I'm just saying it is possible, not that it is a good idea. Once your server crashes or you run out of memory due to w/e reason, data is going to be lost. (Of course within the actual implementation you want to cache data for current matches in some way and keeping objects in memory is way to do so).
I'd recommend to use a database.
Within the database, you can then store and access information about the matches like the score, which users subscribed, who played, etc.
JSON is just a way to represent the data/objects that will be shared between the server and the client. You can use JSON to encode request and response data/bodies.
The user has to be informed about the updated score. There are two basic ways to do so. Push or Pull. With pull, the client will check for updated scores after fixed intervals or actions. With push, the server will notify the client about changed scores which will cause him to update the information. Since you are planning on doing a live application and using Java anyways, push seems to be the better way to go.
Last but not least let's have a look at a possible implementation using
Webserver (API endpoints + database)
Administrator (keeps score updated)
User (receives updates)
We assume that the server will respond to HTTP Requests (POST#/api/my-endpoint) with JSON-Objects.
Possible flow
1)
First the administrator creates a match
REQUEST
POST # /api/matches
body: team1=someteam&team2=someotherteam
The server now will create a match object and store it in the database. The response will contain information about the object and whether the action was successful.
2)
The user asks for a list of matches
REQUEST
GET # /api/matches/curret
The response will be a JSON object containing a list of current matches.
RESPONSE
{
matches: [
{id: 1, teams:...}, ...
]
}
3)
(If push)
A user subscribes to a match
REQUEST
GET # /api/SOME_MATCH_ID/observe
The user will now be added as an observer for the match. Again, the response contains information about whether the action was successful or not.
4)
The administrator updates a score
REQUEST
UPDATE # /api/SOME_MATCH_ID
body: team1scored...
The score now gets update on the server (in memory/database) and the user will be notified about the updated score.
5)
The user gets the updated score
REQUEST
GET # /api/SOME_MATCH_ID
RESPONSE
... (Updated score in some way)
I want to trace user's actions in my web site by logging their requests to database as plain text in Django.
I consider to write a custom decorator and place it to every view that I want to trace.
However, I have some troubles in my design.
First of all, is such logging mecahinsm reasonable or because of my log table will be enlarging rapidly it causes some preformance problems ?
Secondly, how should be my log table's design ?
I want to keep keywords if the user call search view or keep the item's id if the user call details of item view.
Besides, IP addresses of user's should be kept but how can I seperate users if they connect via single IP address as in many companies.
I am glad to explain in detail if you think my question is unclear.
Thanks
I wouldn't do that. If this is a production service then you've got a proper web server running in front of it, right? Apache, or nginx or something. That can do logging, and can do it well, and can write to a form that won't bloat your database, and there's a wealth of analytical tools for log analysis.
You are going to have to duplicate a lot of that functionality in your decorator, such as when you want to switch it on or off, or change the log level. The only thing you'll get by doing it all in django is the possibility of ultra-fine control, such as only logging views of blog posts with id numbers greater than X or something. But generally you'd not want that level of detail, and you'd log everything and do any stripping at the analysis phase. You've not given any reason currently why you need to do it from Django.
If you really want it in a RDBMS, reading an apache log file into Postgres or MySQL or one of those expensive ones is fairly trivial.
One thing you should keep in mind is that SQL databases don't offer you a very good writing performance (in comparison with reading), so if you are experiencing heavy loads you should probably look for a better in-memory solution (eg. some key-value-store like redis).
But keep in mind, that, especially if you would use a non-sql solution you should be aware what you want to do with the collected data (just display something like a 'log' or do some more in-deep searching/querying on the data).
If you want to identify different users from the same IP address you should probably look for a cookie-based solution (if you are using django's session framework the session's are per default identified through a cookie - so you could just simply use sessions). Another solution could be doing the logging 'asynchronously' via javascript after the page has loaded in the browser (which could give you more possibilities in identifying the user and avoid additional load when generating the page).
I need a way to stash some data that is global to the browser. If I open a new window with a URL from my app, e.g. via a bookmark, I need to access some data that was created in another window and never sent to the server.
As far as I can tell the only thing that is global to the browser and not just a window, (like window.name), is a cookie. The problem I'm running into is if I set a cookie the cookie is then sent with every request to the server, but I don't ever want this data on the wire. Is there any way to set a cookie and just use it purely as a bucket for storing some data and never send that data to the server?
The HTML 5 storage API looks like exactly what you want here, but unfortunately it's only supported by a handful of browsers right now.
Is there any way to set a cookie and just use it purely as a bucket for storing some data and never send that data to the server?
No.
You'll need to look into a plugin that provides dedicated offline storage facility, or use the HTML5 storage API and tell everyone to upgrade their browsers
If you decide to go the plugin route, as far as I am aware you have 3 options:
Google Gears
Flash - it has an offline storage facility - you could write a small flash app to store things using this facility, then interop with it from javascript.
Silverlight also has offline storage - as with flash you could write a small app to do the storage, then interop with it from javascript.
I'd probably look into using flash first, as everyone already has it.
Development would likely be a lot easier if you were to use silverlight. It's not as widely installed, but it is spreading pretty rapidly. Last I heard* something like 30% of browsers had it installed which is pretty impressive.
Google gears would unfortunately be a distant third. People are going to be installing flash and silverlight for other reasons, but nobody has gears.
*This is an entirely unsubstantiated quote, but does seem to fit with what I've seen on various people's computers, etc.
Can you mandate that your users install Google Gears? It's a javascript API that lets you store local info- also lets you persist between sessions, which may be useful for your app.
Why not just read a field in the parent window using window.opener ? Or if you've three windows running - parent and two children which I think you might be implying then read/write to a hidden field in the parent from the children.
Sounds like your app is running 100% local, if that is the case the browser isn't the way to go anyway. Cookies can be easily deleted. If your app isn't local the webserver should be the one supplying information. Cookies are never the correct way to store sensitive information or information that should persist over longer amounts of time.