Service/framework for hosting a simple CPAN-like file database? - google-app-engine

Lets say I have a program or language and I want to create a service for users to be able to share files related to my program or language.
For example, if I had a circuit modeling program, I would want users to have a place to share circuit models of common devices. If I had a real time strategy or FPS game, I would want players to have a place to share maps for the game. If I had a programming language, I would want people to have a place to share libraries written in that language like CPAN is for Perl or PyPi is for Python.
Is there a service or framework for putting together such a database simply? If there's not, I was considering putting together a Google App Engine template program for this kind of application. I haven't used Google App Engine, but it's my impression that it's well suited for this kind of application.

In the broadest sense, it sounds like you're looking for a CMS. In more specific terms, though, no, I'm not aware of anything specifically designed for user-submitted content.
My own site, NUMA, runs on App Engine and does pretty much exactly what you describe. It's custom-written for the game it's based around, though.

Related

Why would i need to add scripting engine in my standalone applications

I would like to know in which scenarios would embedding scripting language in my C projects help me.
I have heard about lua which the developers embed in their projects to extending their software applications but why developers prefer to extend their applications using some scripting engine rather then the primary language?
This mostly comes down to who ends up using your applications and what they are using it for. If the application needs no per-user customization, then there's no need for scripting. New functionality can be added normally as part of the application.
However, like in game engines, if the users need to create/script custom behaviour into the application there has to be some way for them to do so. You could try to make your users write their scripts in the language of the application, however in the case of C and many other languages, this requires the code for the application to be recompiled (Not to mention the fact that your users might not be programmers and could benefit from a more high level scripting language).
By adding a scripting engine, you allow your users to add their own (limited) functionality to the application without needing to understand or recompile the entire codebase.
tl;dr Scripting engines make sense if your users need routinely to add custom behaviours to the application.
Regarding your "scenario" question : adding a script engine to your standalone (C or C++ for instance) application is the most direct way to combine the performance of a dedicated engine with the expertise of your power users.
No matter the field of you standalone application, thanks to the ability to write scripts, a power user will usually be able to get the most of it by creating dedicated or project-centric workflow.
The script interface brings a safe and secure environment that is suited for such users whose primary skills is generally not to deal with C/C++.
This leads to your second question : a script API perfectly (using Lua or Squirrel, for instance) makes sense if the primary language needs low-level programming skills. Typically, and application written in C++ will require your power users to write plugins using a C++ SDK.
On the opposite, if your standalone application is written in Python, the benefit of embedding Lua is far from obious in my opinion.

What is the best approach of creating a talking bot?

When creating a AI talking bot what kind of methods of design should I use? Should it be one function, multiple modules, should it have classes?
Understanding language is complicated, so the goal you need to determine first is what aspect of language you want to understand.
An AI must be able to understand what the person says to it, then relate it to what it already knows, and then generate a legitimate response.
These three steps can all be thought of as nearly independent, so you need to address each on its own.
The brain, the world's best language processor, uses a Neural Network, but that's not likely to work well for you.
A logic-based proof solving system, where facts that follow from facts are derived would probably work best, and I know of at least one system that uses it fairly effectively.
I'd start with an existing AI program (like the famous Eliza) and run its output through a speech synthesizer.
Some source for Eliza is available here. One open source speech synthisizer is FreeTTS.
If you're using a language other than Java, there are similar candidates AI bots and text-to-speech code out there.
I've started to do some work in this space using this open source project called Talkify:
https://github.com/manthanhd/talkify
It is a bot framework intended to help orchestrate flow of information between bot providers like Microsoft (Skype), Facebook (Messenger) etc and your backend services. The framework doesn't really provide implementation for the bot providers yet but does provide hooks into its natural language recognition engine.
The built in natural language recognition library can be used to classify sentences to topics which you can then map to skill functions.
Give it a try! I'd really like people's input to see if how it can be improved.

I know the big picture but can't put it in place

I'm interested in web development and by that I mean the bigger projects like facebook or twitter. I know the basics of java, css, php and mysql. I know there is a lot more out there. I read about it. But I don't know what the purpose is and how to put in place.
Things like: Scribe, thrift, casandra, Unix/Linux, shell/perl/python scripting, PostgreSQL, MongoDB, non-relational NoSQL datastores, JVM, nginx
I want to know why they need it, how they use it and what te purpose is.
What I need is a book like technical background of facebook for dummies or so.
Are there any books or websites that explain this from scratch?
Thank you!
EDIT:
Thank you for your answers! You have been very helpful. I was in the assumption, experienced programmers know almost anything about the technology there's used today. But as I read, you can only know so much and I need to figure out which technology to use. I take on the encouragement to start building small. And will take on php and improve my skills from there.
Thanks again!
http://highscalability.com/
This is one of the best sites out there. There are several case studies describing what and why many websites use, and pointers to further references. I would also look at the Google Scalability Conference 2007 talks
http://www.google.com/search?q=Google+Scalability&hl=en&client=firefox-a&hs=YUg&rls=org.mozilla:en-US:official&prmd=v&source=univ&tbs=vid:1&tbo=u&ei=fl4OTPUkorIwueCQxQw&sa=X&oi=video_result_group&ct=title&resnum=4&ved=0CDIQqwQwAw
It's all about choosing the right tool for the job in my eyes. There is so much technology out there it's impossible to learn it all. Just choose the subset that will work for you.
The best place to start is by building small simple websites, and as you come accross problems that you need solved you research the tools needed to solve those problems.
If you attack all of the areas at once, it's going to be overwhelming and you will not get anywhere.
For a general overview on what each of the technologies does, Wikipedia gives a good overview on most technologies.
If you are interested in database content which it seems like you are, a good place to start is reading up on normalisation.
Scribe, thrift, casandra, Unix/Linux, shell/perl/python scripting, PostgreSQL, MongoDB, non-relational NoSQL datastores, JVM, nginx
Those I would search on Wikipedia for to get a quick overview. Facebook is written in PHP/MySQL. There are some books on the subject of creating social networking sites, and some books have gotten decent reviews on Amazon.com, however, I have not read any of them myself.
If I were you, I'd start with PHP/MySQL and sit down and write a simple social network. Break the project down into components and tasks and Google for each challenge you encounter such as sessions, database structure, security, friend structure, and processing POST and GET requests.
You'll learn a lot and you get the big picture. Once you see the big picture, you can take another look at different technologies that are available and then decide which component you could have developed better with other tools. I personally don't think that looking too much into the technology available is good for someone who is still in the beginning stages. Start doing, learn from it, and then your questions become much more specific and a lot of things will make more sense.
The problem you're having is you're looking at smaller, specialty products, and not at larger, more mature technologies. Wikipedia will actually give you a decent overview of most of the medium-and-large projects out there.
Cassandra, Hadoop, Mongo, and NoSQL are all lovely... but they're specialty tools. SQL is a general purpose solution that works for 99% of the sites on the net.
Unix/Linux isn't a specialty tool; you might want to try going to Ubuntu's website and installing Linux, and just using it day-to-day, the way you'd use Windows. When you need to figure out something new, like setting up a webserver, do it on the Linux box and a Windows box, and you'll eventually learn linux pretty darn well.
As far as scripting, O'Reilly makes a great line of books on Bash, Perl, and Python.
JVM is a Java Virtual Machine, which is a core of getting Java code to go. Sun's website has a great set of tutorials on learning Java.
It might be much, much easier to pick a project (or three) that you'd like to learn, and learn some of these by doing. I'd probably suggest learning some SQL before learning the newly established alternatives; that lets you learn the rest of the system, as SQL is pretty easy. Once you've got the rest of the thing solid, try swapping in a NoSQL solution at that point.
There are a lot of frameworks that do a lot of different things. You've named a lot of different things from a lot of different areas. The best way to think of these things is to group them by category. Here's an example:
Suppose you have a laptop and you want to host a website. You'll need the following at a minimum:
1) Web Server software. Two popular options are Microsoft's IIS and Apache Web Server.
That's really all you need. You can set up your www_root folder and load files into it. Assuming everything is configured properly, you can now load HTML pages into that folder and access them through your IP address. Every page you view in your web browser is in HTML format. CSS is a stylesheet language that defines how your HTML will be formatted. You can also start writing Javascript, as most modern browsers support the client-side scripting language.
Chances are you'll want the following as well:
2) Database software. Two popular options are Microsoft's SQL Server and MySQL
3) Server-side scripting. PHP is very popular, as is ASP. You'll need the runtime deployed on your server. Python, Ruby, Perl, etc all fall under this category.
4) Web Application Framework(s). This will provide you with libraries for your language of choice to help develop web applications and websites. CakePHP, Ruby on Rails, and the Google Web Toolkit are examples of web application frameworks.
Additionally, you may want to utilize:
5) Additional libraries. JQuery, for example, is quickly becoming a popular library for Javascript that handles a lot of common tasks for you. Instead of writing complex effects code and what-not yourself, just use the pre-written code in the JQuery library.
6) Data interchange technology. If you are passing a lot of information back and forth, you will likely want to encapsulate this data in a logical format. Ideally, this format would describe the data and allow your applications to easily read/process it following a standard. This is where XML and JSON come into play.
I can't recommend a good book for you to learn this stuff, but I feel that the collective replies to your question here should be more than enough to get you started.
Ultimately, what you need to do is determine what technologies you need, and then choose the right one for the job. Don't go building an application using Ruby on Rails just because it's what Twitter used, but rather choose it because it provides some advantage to you over the other options.

Which web solution should I use for my project?

I'm going to create a fairly large (from my point of view anyway) web project with a friend. We will create a site with roads and other road related info.
Our calculations is that we will have around 100k items in our database. Each item will contain some information like location, name etc. (about 30 thing each). We are counting on having a few hundred thousand unique visitors per month.
The 100k items and their locations (that will be searchable) will be the main part of the page but we will also have some articles, comments, news and later on some more social functions (accounts, forums, picture uploads etc.).
We were going to use Google AppEngine to develop our project since it is really scalable and free (at least for a while). But I'm actually starting to doubt that AppEngine is right for us. It seems to be for webbapps and not sites like ours.
Which system (language/framework etc.) would you guys recommend us to use? It doesn't really mater if we know the language since before (we like learning new stuff) but it would be good if it's something that is future proof.
I think that GAE can do the job. Google claims that Google App Engine is able to handle 5 million visitors for free and you will have to start paying only if you exceed their free quota.
It's also pretty easy to get started. If you don't have experience on administrating websites and choose a regular hosting service, you will have to worry about several things that you don't even imagine now.
My only concern would be with respect of the kind of data and queries you will have to do, since it does not have a relational database. Anyway, there is an open source project for GAE, called GeoModel that gives GAE the ability to do complex geo spacial queries, like proximity fetch. Have a look at their tutorial and the demo app.
About your impression that GAE was intended only for small web apps, there are a couple of CMS that run on it.
Good luck!
If once of your concerns is scalability, and you don't want to depend on expensive or commercial tools, I would recommend that you take a look at this tech stack:
Erlang - A programming language designed for concurrency and distribution.
Nitrogen - An Erlang web framework with a lot of cool stuff, like transparent AJAX.
NoSQL scalable databases, such as CouchDB or Riak - Save the the hassle of SQL code and are more scalable than plain MySQL. Both has direct native Erlang API.
To be honest, I don't know if this tool set is your cup of tea; These are not mainstream solutions. I just suggest these to everyone who ask about size-sensitive web applications.
All serious web frameworks will provide you with what you need. The real issues (for example scalability) might be tackled in a different way depending on what you use, but you wont be limited if you choose a well-known one. The choice of database system might be more important for that (sql vs nosql), even if both of those will do fine too.
It's all about
knowing how to use
enjoying to use
the tool(s) you've chosen.
In either case, name-dropping some suggestions:
Rails (Ruby)
Django (Python)
Nitrogen (Erlang)
ASP.NET MVC (C#)
And please note, if you really want to learn everything from the bottom, you'd be fine with any of these (or one of the other gazillion out there). But if you want to perform your best, choose one that supports a language you know well or uses techniques/tools you have experience of etc. Think twice about how you value this is fun and we learn a lot against we want to be productive and do a really good job.

Pointers towards developing a quick and dirty business app

Some people have approached me lately about creating a business app for them (I'm a computer tech student specializing in programming, with a bit of experience in systems and driver programming) and it does sound simple, but I don't really have much of an idea how or where to start.
It should be a small-ish app with a database backend. Basically keeping track of invoices, clients, products and the attached data.
Are there any APIs that would make creating such an application much faster and easier? Platform isn't really an issue. I have a Mac, a Windows PC, and I am somewhat well-versed in linux in general, and the client will move to a platform of my choice.
I know very little MySQL, I know Objective C, C and a few others, but building a database product this way seems like a very complicated endeavour considering that a large amount of the code I'll be writing has probably been written before and by better programmers than I.
EDIT : If possible, I would definitely like not having to play around with web frameworks. This is not to say I don't want to see them, it's just that I'm not used at all to the web development model.
I would suggest that you look into Ruby on Rails for soemthing like this. It will take care of a lot of the low level details of database access for you and because it is built around the Model-View-Controller paradigm, it will take away some of the architectural decision from you and make you focus on getting the app done. Using Ruby on Rails, I've built a couple of sites of smallish scale that sound like what you have done in no time at all.
For quick and dirty, I suggest Ruby on Rails (if you fancy a bit of Ruby), or Grails (if you fancy a bit of Java/Groovy, and is essentially the Java platform equivalent of RoR).

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