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Hello,
I'm designing an application that simulates a university application and courses system.
I'm looking for a design pattern for this case:
I have a base class Course, and 3 deriving classes for 3 type of courses.
each course should have a list of pre-courses that need to be taken in order to take the course. The pre courses can be any of the 3 types of courses.
I thought of using the graphic-shape-picture design pattern, but it's not the very same case.
Will appreciate any idea!
Thank You
Orlya
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Maybe the "Course" class has a collection of Course class references or Course class unique id's.
led mike
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Hi,
Any suggestions on how I can build an client/server architecture which has a browser-based RIA (Rich Internet Application using flex, .NET 3.0 or other) client and a server architecture that can run either on a web server (SOAP/Web services), or as an ordinary TCPIP-based application server. The option for deployment will be given the user at install time.
I understand that I need to write communication services for both options, but what is the optimal choice of technology/method?
The goal is to give the option to install the application on a standalone PC without IIS or any other web server installed, but still let the user interface be browser based.
Jay
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Thanks. However, don't focus on the RIA part of my question. That is only to show that I want a "modern" browser-based UI experience. It is the dual-protocol communication strategy which is the interesting part to me. I want to have a web/internet application (default) to be able to run on a standalone computer environment which hasn't got a webserver installed.
Jay
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We are having some communictions problems. You want an internet application without the internet? 
If you want to use a Web Browser interface for your UI in a desktop application you can use the WebBrowser control.
At this point I have no idea what you are trying to accomplish.
led mike
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Jay
You need to be a little more clear on what you mean by web server and ordinary based TCPIP-based application server.
By web server I am assuming you literally mean a web server as in Apache or IIS. And TCPIP-based application serevr, I assume you mean Tomcat, Websphere, etc. Right?
I am currently creating an RIA using flex with a .NET backend.
dan
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Hi Dan,
Yes, you are right with the first one: I mean web server as in Apache, IIS etc. The second one I simply mean a server application that can render the RIA client without running on a web server.
I will try to explain be telling you about the scenarios I see:
Scenario 1 (main): The user downloads the application and deploys it on a webserver, so that the application is available for all users on the intranet (through the RIA client)
Scenario 2: The user which will be one that decides that the application should be downloaded and tested on the company's own data before purchase, should be able to deploy it on his own computer/laptop as a standalone application with a database connection to the company's own production/test databases. This computer/laptop will normally not have any webserver locally installed and we cannot expect that the user will be interested or have the skills/patience to install the local IIS (or other Web server) before he can test the application. Therefore the application must be able to be deployed as a "standalone" configuration without a webserver to render the client.
I hope this clarified my requirements.
In the meanwhile I have found a class in .NET 2.0 (HttpListener) which can implement a web application without a web server.
I appreciate more comments and ideas.
Jay
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i'm making an application in vb.net
i made the database and i need to go to the classes...
amy documentation can help me ?????
while i'm trying i faced a problem with foreing keys
ex :
table house (id,name,address)
table room (id,name,housid)
so i pass to class by wich way :
---------------------------------------------
1-
class house
- id as integer
- name as strind
- address as string
class room
-id as integer
-name as string
-hous as house
-----------------------------------------------
2-
class house
- id as integer
- name as strind
- address as string
- rooms () as room
class room
-id as integer
-name as string
-----------------------------------------------
3-
class house
- id as integer
- name as strind
- address as string
- rooms () as room
class room
-id as integer
-name as string
-hous as house
wich choice ...
if there are an alogrithm to make the pass from db to oo so can u help me ???
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I go for #3.
from DB to OO, check http://www.mygenerationsoftware.com. My Number 1 choice.
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opps
this is an application ...
i need to know the algos ....
if there are a documentation or something like that ...
thanks a lot
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What you describe is a tree. Depending on the direction you want to go in the tree you should choose 2 or 3: 2 if you go from the root to leafs (you have the house and you want the rooms) or both ways (previous + you know the room and want to find the house it belongs). Choise 3 is more complete and memory used to keep the pointer to house is small 4B.
Usualy I do like this: a row in a table contains all the members of a class - each row = object; procedures that insert/update/delete in the database are methods of the class, each method calling corresponding stored procedure. Columns (members of classes) are accessed (read/write) through properties or functions offering a good consistency check even from the input of data.
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Hi,
I´m developing a .NET 2.0 library (dll) which basically is a stamp clock that logs working time and prints job specifications. The application separates UI from logic by a library design approach. I plan to implement both a Windows Form UI and a AJAX UI on the library.
The question: What is a good design regarding how to store the logged time entries/data? Shall I store the data in a mdf database or XML files or make an interface an let the application that make use of the library (UI) implement the database interface to enable custom database usage (by doing this every implementation a database setup has to be carried out = bad)?
I know this depends on the purpose and usage. Is the mdf approach a good way to store data in both a webapplication and a desktop app? I find this a bit confusing. ^_^
Thanx in advance
regards
/Christoffer
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http://en.wikipedia.org/wiki/Model-view-controller[^]
Model
The domain-specific representation of the information on which the application operates. The model is another name for the domain layer. Domain logic adds meaning to raw data (e.g., calculating if today is the user's birthday, or the totals, taxes and shipping charges for shopping cart items).
Many applications use a persistent storage mechanism (such as a database) to store data. MVC does not specifically mention the data access layer because it is understood to be underneath or encapsulated by the Model.
led mike
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Hi all,
i want to study internals of fat file system.
so for that purpose which book i should use as an reference book.
just what
"The design of unix operating system (Maurice J Bach)"
does to understand the unix file sysetm.
Is there any such book by which i would be able to understand the fat file system.
If anyone know's please tell me.
i want to create a file system driver for fat fs.
Thanks and regards
Harshal shete
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There was a book which presented a DOS compatible operating system, but I think it's out of print. However, you could look here[^] where you can download a copy of the FAT32 specification from Microsoft.
Steve S
Developer for hire
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I'm working on a VB application that may resemble MS Money. You have a toolbar at the top and a spine on the left that have specific tasks that may be performed for each main function. For example, on the toolbar there is a "Customers" button. Once clicked, the spine on the left will have "customer" specific tasks (i.e., Add New, Select, Reports, Open Issues, etc.... To the right will be the results of whatever task they select from the spine. Since any of these tasks may involve several pages or forms, I thought about using groupboxes or panes for each of the task; however the maintenance of all those controls could be overwhelming.
So I guess my questions is, if you think of how MS Money functions, what is the best approach for designing a rich client application? Possibly using customer controls for each function? Would I group them all in one main "Customer" control??
Any help (VB) would be appreciated.
Bob
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Bob,
Assuming your using VB.NET 2005.
There are tons of techniques. Using a MDI approach would be easy also. You could define a single class for controlling which one is currently visible.
Another approach, is to use multiple Panels on the same form. Hiding each one but the current one.
You can optionally use a Tab control, only showing a single tab at a time.
Of course, I'm not clear on how MS Money does it. But there are also docking controls like the split panel control.
If you are not using VB.NET 2005, instead you are using VB6. Then you'll have to do a little bit more coding, and some of the controls listed are not available in VB6.
In VB6, you can use multiple Panel controls. Set the Left Property of the ones you want to hide to -10000. This moves it completely off the form. You can swap them in and out by setting their corresponding Left property to the setting that makes them visible.
Although, I've created some fairly complex applications in VB6. I've been using VB.NET for quite sometime now.
Hope this helps!
~ CodeDoctor ~
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hai,
i want to develope asp.net web project.any tools to design the project specs,Preparing DSD.
Thanks and regards,
surendra
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I'm considering embarking on my first C# adventure by way of creating an inventory system for the electrical power industry. I spent much of tonight trying to lay out an object heirarchy and only ended up confusing myself.
The top level class, InventoryItem, is a no-brainer. The next level is almost as simple - Overhead, Underground, Substation, Multi-use. Then it starts to get complicated. For example, a simple disconnect comes in multiple flavors - solid blade or fused, 15kV or 25kV, 200A or 600A, load-breaking or non-load-breaking, ganged or single-phase, 1-, 2, or 3-pole. That I can deal with by creating subclasses. But each type is made by multiple manufacturers, and sold by multiple vendors, each with its own pricing. No one vendor sells all products from a single manufacturer, and no manufacturer sells all products through one vendor. Each vendor's pricing is different, even for the same item from the same manufacturer, and prices change weekly. To make matters more interesting, several manufacturers make the same item, interchangeable at will, and we stock equivalent parts from multiple manufacturers and vendors as one SKU.
The goal here is to keep track of inventory items at the vendor/manufacturer level, but accumulate costs at the SKU level to be used for estimating future jobs.
Can someone among you geniuses suggest a logical class heirachy for this mess? I think the coding will be fairly straightforward, but the difference between a raging success and a dismal failure lies in getting the structure right from the get-go. Thanks, in advance, if you have a useful suggestion.
"...a photo album is like Life, but flat and stuck to pages." - Shog9
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Why are you hard-coding the items? Wouldn't it be better to create a database?
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What makes you think he is not using database? Mapping DB records on classes is nothing strange...
"Throughout human history, we have been dependent on machines to survive. Fate, it seems, is not without a sense of irony. " - Morpheus
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Roger Wright wrote: Can someone among you geniuses suggest a logical class heirachy for this mess?
It would take more than a "genius" to do so because there is no logical hierarchical model for something that isn't, inherently, hierarchical. It isn't a "mess"; it's just not hierarchical.
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- Do you have an existing GIS ?
- Do you model/maintain phase info ?
- Do you model secondary runs from transformer to meter ?
- Do you model transmission (to subs)
(ok, only effect the fields, but i'm curious  )
You will not want to break down the tables or class' beyond the type level.
e.g.
InvItem
|__ Fuse
|__ Transformer
| |__ 1 phase (optional)
| |__ 3 phase ('')
|__ Capacitor
|__ Switch
|__ ...
Some of the elec inv systems i've seen didn't even maintained separate tables for facility types.
It was one big table with InvId, vendor, manuf., manuf sku, price, price date, (elec util) sku, description, ...
Decription held "40A fuse", ...
You will make life easier if you match the facility table break down that you use in you GIS (assuming you have a GIS, assuming you don't want to throw all inv items into one table).
The inv system doesn't (generally) care about details like phases, amps, voltage, ... that should all be in the GIS table (that's why you can throw all that info into a inv desc field).
The GIS table should just contain the InvId (unique for vendor/manuf/manuf sku) and optionally the (elec util) SKU (read-only in GIS, to validate InvId), plus the detail info like phases, voltage, circuit, ohug, state, ... .
Of course going to the next level, you break out the detail info in the inv tables, and have the inv system tied to the GIS so that the GIS placement routines use the inv system to display validation tables for the digitizer to select from (then pull phase, ... from inv tables and copy into gis fields).
Once you have all this info you will want to gen std drawings e.g. std pole, std gang-switch (attachment for a pole), ... . This system can then be used by the eng to do quick designs and part/cost estimates. A full system includes things like how many man hrs it takes to install each part as well.
If i were coming to you guys as a consultant the system i would propose would depend LOT on what you already have (what GIS - what schema, do std drawing exist - what format, current inv data system/format, ...) ... and of course how much money you want to spend .
...cmk
Save the whales - collect the whole set
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cmk wrote: Do you have an existing GIS ?
Yup, and we paid a bundle to collect it. Unfortunately, now that I've gained more understanding of the GIS schema the consultant created, I see that it was a crappy job, full of unused fields, duplicates, and unnecessary data.
cmk wrote: Do you model/maintain phase info ?
- Do you model secondary runs from transformer to meter ?
Not yet, though we collected conductor/structure data with the intent of one day modelling it. Ideally, the GIS geodatabase would be the ideal place to store details about structure and implementation, and a separate db would contain just stock and reordering info. The more important task is probably to clean up the mess in the GIS schema, but the priority from a business standpoint is to track and maintain adequate stocks of spare parts - two very different jobs.
The info in the GIS system should probably be treated as a super-inventory, with assemblies tracked as finished goods created from parts drawn from stores and tracked by the general inventory. We use RUS standard structures, with minor variations, for most of our network, and I have the standard drawings in AutoCAD format. Since the new AutoCAD 2007 adds the ability to link the data fields in a table to an external database, it should be fairly straightforward to generate up-to-date costs at the structure level for future construction using average costs from the inventory db. That would also, when coupled with accurate GIS data, give us current replacement costs for installed plant.
Hmmm... You've given me much to rethink - Thanks!
"...a photo album is like Life, but flat and stuck to pages." - Shog9
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