Star rating system - database

I'm building an application as part of a course project which allows users to rate an place/event .
My basic question is how should I proceed in this ?
In what language should I write my code ?
If a user provides a 5-star rating, how do I collect it and put it in the database ?
Any guidelines on how to put the initial steps would be very helpful as my knowledge relating to web services is very weak.
Any help/pointers to more information would be very appreciated

Your question is overly vague and isn't related to system administration, so it's probably going to get closed once someone comes along with the appropriate privileges. However, as long as it's here...
My basic question is how should I proceed in this ?
If you are completely at a loss you may want to spend some time consulting with your instructor, who may be able to suggest likely sources of information and provide some direction for your work.
In what language should I write my code ?
You should write your code in a language with which you are familiar that allows you to fulfill the requirements of the project. Anything else will needlessly extend the amount of time it takes to complete the project. If your goal is to learn a new language, you face a mind-numbing number of choices. Python, Ruby, and PHP are all see wide use in web applications. On Microsoft platforms, .NET is quite popular. You will find proponents and detractors for all of them.
If a user provides a 5-star rating, how do I collect it and put it in the database ?
This looks suspiciously like you're asking us to do your assignment for you.

Related

Genetic Algorithm vs Expert System

I'm having some doubts about which system should I use for a new software.
No code has been written yet, I'm just breaking apart all the needs and only then start coding.
This will be implemented in a computer company that provides services for other companies, onsite and remotely.
These are my variables:
Number of technicians
Location of customer
Type of problem
Services already scheduled for the technician
Expertise of the technician about the situation
Customer priority
Maybe some are missing, but these are the most important ones.
This job is being done manually, and has humans, we fail to see the best route to be taken sometimes.
Let's say that a customer calls with a printer problem.
First, check which tech knows about printers.
Then, is the tech available? far from the customer? can it be done remotely (software issues)?
Can it be done by another tech who is closer from the customer location?
Does this customer have more priority than the other where the same tech should be going?
Is the technician schedule full? If yes, pass to another printer/hardware tech.
I know my english is not perfect (not my natural language), but I'll try to provide more details or correct the text as needed.
So, my question is this, what kind of approach would you take? Genetic algorithm seems nice for this kind of job, and I also have some experience with GAF and WatchMaker (Java GA Framework). However, when reading the text above, an expert system seems also appropriate.
Have someone done something like this?!I had search for this kind of software and couldn't find anything alike.
Would another approach be better than the two asked?!
Also, I'm building up a table with all the techs capabilities and expertise, with simple rules like, 1 to 5 about each expertise. This is also a decision factor.
Thanks.
Why not do both? Use an expert system (a rule engine) to define your constraints and use a metaheuristic (such as Local Search or Genetic Algorithms) to solve it. The planning engine OptaPlanner (java, open source) does exactly that (by using the rule engine Drools). The architecture look likes this:
Here's a video demonstrating the constraint flexibility on the vehicle routing problem (VRP). Your problem seems to be an advanced variant on VRP (which is a variant on TSP).
Maybe you can start off with TSP,
here http://en.m.wikipedia.org/wiki/Travelling_salesman_problem
I guess it only deals with the distance.

Conversation bot source or API

I would like to make a bot that can carry on a simple conversation. I would like to be able to supply the bot with parameters about the things it knows and how it responds to certain subjects. I am wondering if anyone knows of any freely available source code or an API for a decent conversational bot.
I would like to use this to facilitate gaming by having computer-controlled characters that interact with the real players without having completely pre-scripted, static dialog. I am hoping that I can find something capable of holding a simple, generic conversation unless asked about a specific topic, at which point it can give specific replies to a pre-set list of specific topics.
I am asking more about the conversational-processing aspect and not so much about a front end or hooks to other apps or anything like that. Initially, I will just make this a local command-line based thing, then if satisfied I am looking into libpurple as an API to access various communication networks once I have the dialog processing ready.
So, does anyone know of any source code or API for something like this? Google brings up mostly tools for things like imified. I'm not expecting there to be a lot. A source code for something that exists that can handle various emotions and topics and such would be awesome, but I'd be happy with something that just holds the simplest of conversations, as there should be something somewhere that does this, seeing how there are multiple IM bots in existence.
In the absence of a good source or API, would anyone happen to know of any good materials about programming an AI that can have a conversation? Again, I'm not talking about PhD papers discussing robots that can pass believably as humans or anything like that; I mean materials that discuss some simple programming techniques that common conversational bots use to hold rudimentary conversations.
Because of the libpurple API, I'll probably be doing this in C++. So C++ resources are preferable but not required.
(edit) I just stumbled onto AIML (Artificial Intelligence Markup Language). I am currently looking into that, and it sounds like it might be promising, especially if there are any pre-made conversational resources available for it, as then I could just add topics to it in the manner I mentioned, if I am understanding it correctly.
AIML is old, obsolete and is a torture to create his database. I suggest you follow this gamasutra's article about chatbot languages. This article describes the ChatScript language, is a great alternative for AIML.
Another language is RiveScript that have a cool clean style, but it seem like a copy of AIML with the same bad concepts.
I'm developing the Aerolito language that is based on YAML, it's just a hobby project and it's not usable yet. =]
In my opinion, ChatScript is the best option for now.
I understand this question is old, but things have changed in the time since the question has posted. Check out the following projects, these bots learn from either text files, irc chat logs or in the case of triplie, they can read websites (albeit not perfectly).
triplie-ng: https://github.com/spion/triplie-ng
cobe: https://github.com/pteichman/cobe
Giorgio Robino mentioned http://superscriptjs.com/ but it's more than just chatscript - it's a superset of rivescript and chatscript and also includes a built-in triple store to implement WordNet etc.

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.

What's the easiest way to Create a User-Friendly front end for a C program on Linux platform

I have a small course project that would best have a user-friendly front end.
It's a network sniffer, I coded the program with C and Linux. And now I am hoping to make it more ``user-friendly".
In c: Getopt
In c++, if relevant: Boost program options
Try to behave like other programs (at the very least provide a useful --help message, and print some sort of simple usage description for invalid arguments). I find the easiest way to understand how to use a program is when its manual page, or even --help message gives examples of common usage cases.
If by user friendly you mean you want to make a gui for it then I would definitely recommend GTK. GTK is one of the more widely use Xserver tool kits and it is written in C. Another plus is that it is written in an object oriented manner. IMO being exposed to how OO programming is accomplished in C is a great thing for all CS students.
If your sniffer has a command line front end, have a look at Eric S. Raymond's The of Unix Programming. In chapter 10, there's a whole section on how to name and format your command line arguments. There's also a POSIX standard for utility syntax.
These approaches won't directly make your program user friendly, only research on your users and analysis of your interfaces will help with this. However, providing an interface that works in ways that users expect will certainly help.
Im no expert in UI Design, or anything in that matter, but taking an interest in the quality of User Interface Design, I came across Aza Raskin, an interface design expert that is head of design for Mozilla Labs. I have followed some lectures and conventions that Aza has done on UI Design, and he said something that is simple, yet makes more sense then anything I have ever learned with UI Design...I may butcher it but its along the lines of
If The User has to think about the design,then it is a bad design
This may seem like an insult to everybody's intelligence, but it makes sense. Something that is user friendly cant be ambiguous to the user. This means that when a user is performing some task/operation, the UI should be presented to them corresponding to the current event or situation.
The UI should be designed so that anybody who picks up your software should be able to navigate through it. This DOESNT mean that they should understand the underlying problem domain, but it does mean that if asked to find a certain functional part of the software, that they could generally navigate themselves there.
Some things to things to think about when using your software:
1) -Do you ever ask yourself, "Do I go here or here?
2) -Do I use tools like bold fonts and italicizing to show emphasis?
3) -Am I sacrificing anything by making certain features "idiot proof"(Read Below)
4) -Am I trying to do too much anywhere just to save time(programming time)
These are just some things that can help straighten out some of your design decisions. In no way is this following any pattern. Like I said, my education in this field is minimal, it is just an interest I have followed.
Regarding #3, It is important that you don't sacrifice any feature or design decision when implementing certain accommodations. If you have something where 99% of your users are using a certain feature, but 1% can be expected to make a different decision, then take this into consideration. Don't sacrifice the design for the 99% of the users to accommodate the other 1%. This doesn't mean don't accommodate the other users, I just mean don't sacrifice the integrity of the design.
If you don't need to interact with the app "live" or only need limited interaction as a command line app then you can write a frontend using PyGTK. If you need to access C libraries then you can use Cython to load and call them.
But regardless of what you choose, be sure to find a professional interface designer. A bad interface can destroy the potential popularity of any app.

Disadvantages of the Force.com platform [closed]

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Closed 10 years ago.
We're currently looking at using the Force.com platform as our development platform and the sales guys and the force.com website are full of reasons why it's the best platform in the world. What I'm looking for, though, is some real disadvantages to using such a platform.
Here are 10 to get you started.
Apex is a proprietary language. Other than the force.com Eclipse plugin, there's little to no tooling available such as refactoring, code analysis, etc.
Apex was modeled on Java 5, which is considered to be lagging behind other languages, and without tooling (see #1), can be quite cumbersome.
Deployment is still fairly manual with lots of gotchas and manual steps. This situation is slowly improving over time, but you'll be disappointed if you're used to having automated deployments.
Apex lacks packages/namespaces. All of your classes, interfaces, etc. live in one folder on the server. This makes code much less organized and class/interface names necessarily long to avoid name clashes and to provide context. This is one of my biggest complaints, and I would not freely choose to build on force.com for this reason alone.
The "force.com IDE", aka force.com eclipse plugin, is incredibly slow. Saving any file, whether it be a class file, text file, etc., usually takes at least 5 seconds and sometimes up to 30 seconds depending on how many objects, data types, class files, etc. are in your org. Saving is also a blocking action, requiring not only compilation, but a full sync of your local project with the server. Orders of magnitude slower than Java or .NET.
The online developer community does not seem very healthy. I've noticed lots of forum posts go unanswered or unsolved. I think this may have something to do with the forum software salesforce.com uses, which seems to suck pretty hard.
The data access DSL in Apex leaves a lot to be desired. It's not even remotely competitive with the likes of (N)Hibernate, JPA, etc.
Developing an app on Apex/VisualForce is an exercise in governor limits engineering. Easily half of programmer time is spent trying to optimize to avoid the numerous governor limits and other gotchas like visualforce view state limits. It could be argued that if you write efficient code to begin with you won't have this problem, which is true to an extent. However there are many times that you have valid reasons to make more than x queries in a session, or loop through more than x records, etc.
The save->compile->run cycle is extremely slow, esp. when it involves zipping and uploading the entire static resource bundle just to do something like test a minor CSS or javascript change.
In general, the pain of a young, fledgling platform without the benefits of it being open source. You have no way to validate and/or fix bugs in the platform. They say to post it to their IdeaExchange. Yeah, good luck with that.
Disclaimers/Disclosures: There are lots of benefits to a hosted platform such as force.com. Force.com does regularly enhance the platform. There are plenty of things about it I like. I make money building on force.com
I see you've gotten some answers, but I would like to reiterate how much time is wasted getting around the various governor limits on the platform. As much as I like the platform on certain levels, I would very strongly, highly, emphatically recommend against it as a general application development platform. It's great as a super configurable and extensible CRM application if that's what you want. While their marketing is exceptional at pushing the idea of Force.com as a general development platform, it's not even remotely close yet.
The efficiency of having a stable platform and avoiding big performance and stability problems is easily wasted in trying to code around the limits that people refer to. There are so many limits to the platform, it becomes completely maddening. These limits are not high-end limits you'll hit once you have a lot of users, you'll hit them almost right away.
While there are usually techniques to get around them, it's very hard to figure out strategies for avoiding them while you're also trying to develop the business logic of your actual application.
To give you a simple sense of how developer un-friendly the environment is, take the "lack of debugging environment" referred to above. It's worse than that. You can only see up to 20 of the most recent requests to the server in the debug logs. So, as you're developing inside the application you have to create a "New" debug request, select your name, hit "Save", switch back to your app, refresh the page, click back to your debug tab, try to find the request that will house your debug log, hit "find" to search for the text you're looking for. It's like ten clicks to look at a debug output. While it may seem trivial, it's just an example of how little care and consideration has been given to the developer's experience.
Everything about the development platform is a grafted-on afterthought. It's remarkable for what it is, but a total PITA for the most part. If you don't know exactly what you are doing (as in you're certified and have a very intimate understanding of Apex), it will easily take you upwards of 10-20x the amount of time that it would in another environment to do something that seems like it would be ridiculously simple, if you can even succeed at all.
The governor limits are indeed that bad. You have a combination of various limits (database queries, rows returned, "script statements", future calls, callouts, etc.) and you have to know exactly what you are doing to avoid these. For example, if you have a calculated rollup "formula" field on an object and you have a trigger on a child object, it will execute the parent object triggers and count those against your limits. Things like that aren't obvious until you've gone through the painful process of trying and failing.
You'll try one thing to avoid one limit, and hit another in a never ending game of "whack a limit". In the process you'll have to drastically re-architect your entire app and approach, as well as rewrite all of your test code. You must have 75% test code coverage to deploy into production, which is actually very good thing, but combined with all of the other limits, it's very burdensome. You'll actually hit governor limits writing your test code that wouldn't come up in normal user scenarios, but that will prevent you from achieving the coverage.
That is not to mention a whole host of other issues. Packaging isn't what you expect. You can't package up your app and deliver it to users without significant user intervention and configuration on the part of the administrator of the org. The AppExchange is a total joke, and they've even started charging 5K just to get your app listed. Importing with the data loader sucks, especially if you have any triggers. You can't export all of your data in one step that includes your relationships in such a way that it can easily be re-imported into another org in a single step (for example a dev org). You can only refresh a sandbox once a month from production, no exceptions, and you can't include your data in a refresh by default unless you have called your account executive to get that feature unlocked. You can't mass delete data in custom objects. You can't change your package names. Certain things can take numerous days to complete after you have requested them, such as a data backup before you want to deploy an app, with no progress report along the way and not much sense of when exactly the export occurred. Given that there are synchronicity issues of data if there are relationships between the data, there are serious data integrity issues in that there is no such thing as a "transaction" that can export numerous objects in a single step. There are probably some commercial tools to facilitate some of this, but these are not within reach to normal developers who may not have a huge budget.
Everything else the other people said here is true. It can take anywhere from five seconds to a minute sometimes to save a file.
I don't mean to be so negative because the platform is very cool in some ways and they're trying to do things in a multi-tenant environment that no one else is doing. It's a very innovative environment and powerful on some levels (I actually like VisualForce a lot), but give it another year or two. They're partnering with VMware, maybe that will lead to giving developers a bit more of a playpen rather than a jail cell to work in.
Here are a few things I can give you after spending a fair bit of time developing on the platform in the last fortnight or so:
There's no RESTful API. They have a soap based API that you can call, but there is no way of making true restful calls
There's no simple way to take their SObjects and convert them to JSON objects.
The visual force pages are ok until you want to customize them and then it's a whole world of pain.
Visual force pages need to be bound to SObjects otherwise there's no way to get the standard input fields like the datepicker or select list to work.
The eclipse plugin is ok if you want to work by yourself, but if you want to work in a large team with the eclipse plugin forget it. It doesn't handle synchronizing to and from the server, it crashes and it isn't really helpful at all.
THERE IS NO DEBUGGER! If you want to debug, it's literally debugged by system.debug statements. This is probably the biggest problem I've found
Their "MVC" model isn't really MVC. It's a lot closer to ASP.NET Webforms. Your views are tightly coupled to not only the models but the controllers as well.
Storing a large number of documents is not feasible. We need to store over 100gb's of documents and we were quoted some ridiculous figure. We've decided to implement our document storage on amazons S3 infrastructure
Even tho the language is java based, it's not java. You can't import any external packages or libraries. Also, the base libraries that are available are severely limited so we've found ourselves implementing a bunch of stuff externally and then exposing those bits as services that are called by force.com
You can call external SOAP or REST based services but the message body is limited to 100kb's so it's very restrictive in what you can call.
In all honesty, whilst there are potential benefits to developing on something like the force.com platform, for me, you couldn't use the force.com platform for true enterprise level apps. At best you could write some basic crud style applications but once you move into anything remotely complicated I'd be avoiding it like the plague.
Wow- there's a lot here that I didn't even know were limitations - after working on the platform for a few years.
But just to add some other things...
The reason you don't have a line-by-line debugger is precisely because it's a multi-tenant platform. At least that's what SFDC says - it seems like in this age of thread-rich programming, that isn't much of an excuse, but that's apparently the reason. If you have to write code, you have "System.debug(String)" as your debugger - I remember having more sophisticated server debugging tools in Java 1.2 about 12 years ago.
Another thing I really hate about the system is version control. The Spring framework is not used for what Spring is usually used for - it's really more off a configuration tool in SFDC rather than version control. SFDC provides ZERO version-control.
You can find yourself stuck for days doing something that should seem so ridiculously easy, like, say, scheduling a SFDC report to export to a CSV file and email to a list of recipients... Well, about the easiest way to do that is create a custom object with a custom field, with a workflow rule and a Visualforce email template... and then for code you need to write a Visualforce component that streams the report data to the Visualforce email template as an attachment and you write anonymous APEX code schedule field-update of the custom object... For SFDC developers, this is almost a daily task... trying to put about five different technologies together to do tasks that seem so simple.... And this can cause management headaches and tensions too - Typically, you'd find this out after getting a suggestion to do something that doesn't work in the user-community (like someone already said), and then trying many things that, after you developed them you'd find they just don't work for some odd-ball reason - like "you can't schedule a VisualForce page", or "you can't call getContent from a schedulable context" or some other arcane reason.
There are so many, many maddening little gotcha's on the SFDC platform, that once you know WHY they're there, it makes sense... but they're still very bad limitations that keep you from doing what you need to do. Here's some of mine;
You can't get record owner information "out of the box" on pretty much any kind of record - you have to write a trigger that links the owner on create of the record to the record you're inserting. Why? Short answer because an owner can be either a "person" or a "queue", and the two are drastically different entities... Makes sense, but it can turn a project literally upside down.
Maddening security model. Example: "Manage Public Reports" permission is vastly different from "Create and Customize Reports" and that basically goes for everything on the platform... especially folders of any kind.
As mentioned, support is basically non-existent. If you are an extremely self-sufficient individual, or have a lot of SFDC resources, or have a lot of time and/or a very forgiving manager, or are in charge of a SFDC system that's working fine, you're in pretty good shape. If you are not in any of these positions, you can find yourself in deep trouble.
SFDC is a very seductive business proposition... no equipment footprint, pretty good security, fixed price, no infrastructure, AND you get web-based CRM with batchable, and schedualble processing... But as the other posters said, it is really quite a ramp-up in development learning, and if you go with consulting, I think the lowest price I've seen was $200/hour.
Salesforce tends integrate with other things years after some technologies become common-place - JSON and jquery come to mind... and if you have other common infrastructures that you want to do an integration with, like JIRA, expect to pay a lot extra, and they can be quite buggy.
And as one of the other posters mentioned, you are constantly fighting governor limits that can just drive you nuts... an attachment can NOT be > 5MB. Period. And sometimes < 3MB (if base64 encoded). Ten HTTP callouts in a class. Period. There are dozens of published governor limits, and many that are not which you will undoubtedly find and just want to run out of your office screaming.
I really, REALLY like the platform, but trust me - it can be one really cruel mistress.
But in fairness to SFDC, I'd say this: the biggest problem I find with the platform is not the platform itself, but the gargantuan expectations that almost anyone who sees the platform, but hasn't developed on it has.... and those people tend to be in positions of great authority in business organizations; marketing, sales, management, etc. Huge disconnects occur and heads roll, or are threatened to roll daily - all because there's this great platform out there with weird gotchas and thousands of people struggling daily to get their heads around why things should just work when they just don't and won't.
EDIT:
Just to add to lomaxx's comments about the MVC; In SFDC terminology, this is closely related to what's known as the "viewstate" -- aand it can be really buggy, in that what is on the VF page is not what is in the controller-class for the page. So, you have to go throught weird gyrations to synch whats on the page with what the controller is going to write to SF when you click your "save" button (or make your HTTP callout or whatever).... man, it's annoying.
I think other people have covered the disadvantages in more depth but to me, it doesn't seem to use the MVC paradigm or support much in the way of code reuse at all. To do anything beyond simple applications is an exercise in frustration compared to developing an application using something like ASP.Net MVC.
Furthermore, the tools, the data layer and the frustration of trying to refactor code or rename fields during the development process doesn't help.
I think as a CMS it's pretty cool but as a platform for non CMS applications, it's doesn't make sense to me.
The security model is also very very restrictive... but this isn't the worst part. You can't currently assert whether a user has the ability to perform a particular action.
You can check to see what their role is, but you can't check if that role has permissions to perform the current action.
Even worse is the response from tech support to "try the action and if there's an exception, catch it"
Considering Force.com is a "cloud" platform, its ability to act as a client to an external WSDL-defined service is pretty underwhelming. See http://force201.wordpress.com/2010/05/20/when-generate-from-wsdl-fails-hand-coding-web-service-calls/ for what you might end up having to do.
To all above, I am curious how the release of VMforce, allowing Java programmer to write code for Force.com, changes the disadvantages above?
http://www.zdnet.com/blog/saas/vmforcecom-redefines-the-paas-landscape/1071
I guess they are trying to address these issues. At dreamforce they mentioned they we're trying to drop the Governor limits to only 4. I'm not sure what the details are. They have a REST API for early access, and they bought heroku which is a ruby development in the cloud. They split out the database, with database.com so you can do all your web development on and your db calls using database.com.
I guess they are trying to make it as agnostic as possible. But right about now these are all announcements and early access so like their Safe Harbor statements don't purchase on what they say, only on what they currently have.

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