Sunday, August 30, 2009

How to get the Application Path in C# - ASP.Net

1) HttpContext.Current.Request.Url.Host
- Displays the Host Name

2) HttpContext.Current.Request.Url.Port
- Displays the Port of the Application

3) HttpContext.Current.Request.ApplicationPath
- Displays the Application Path

Tuesday, August 25, 2009

linq tutorial

Referred from URL: - http://www.programmersheaven.com/2/CSharp3-4

Linq is short for Language Integrated Query. Imagine we have a list of orders. For this example, we will imagine they are stored in memory, We want to get a list of the costs of all orders that were placed by the Supplier identified by the number 25.

Reading from Memory
List Found = new List();
foreach (Order o in Orders)
if (o.SupplierID == 25)
Found.Add(o.Cost);

SQL Query
SELECT Cost FROM Orders WHERE SupplierID = 25

Linq query
var Found = from o in Orders
where o.SupplierID == 25
select o.Cost;
OutPut
Cost: 159.12
Cost: 2.89

Adding More Columns for returning
var Found = from o in Orders
where o.SupplierID == 84
select new { o.OrderID, o.Cost };

A Few More Simple Queries
var Found = from o in Orders
where o.SupplierID == 84 && o.Cost > 100
select new {
o.OrderID,
o.Cost,
CostWithTax = o.Cost * 1.1
};

Ordering
var Found = from o in Orders
where o.CustomerID == 84
orderby o.Cost ascending
select new { o.OrderID, o.Cost };

Grouping
var OrdersByCustomer = from o in Orders
group o by o.CustomerID;

Joins
var Found = from o in Orders
join c in Customers on o.CustomerID equals c.CustomerID
select new { c.Name, o.OrderID, o.Cost };

Query Continuations
var OrderCounts = from o in Orders
group o by o.CustomerID into g
select new {
CustomerID = g.Key,
TotalOrders = g.Count()
};

Saturday, August 15, 2009

Check List for Managing a Program - Glen B. Alleman

Post by Glen B. Alleman Click link for more-

http://herdingcats.typepad.com/my_weblog/2009/08/check-list-for-managing-a-program.html

  • A clear, concise statement defining the program has been prepared and reviewed by knowledge parties for consensus.

  • Performance objectives that follow written guidelines and contain actual calendar dates for completion.

    A Work Breakdown Structure developed to a level sufficient to prepare accurate estimates of cost, resources and working times for all program activities.

  • A Statement of program scope that clearly defines the limits of what will and what will not be done or delivered as a result of the program.

  • Specifications that must be met are either identified and the "owners" of these specification concur with the outcomes.

  • Tangible deliverables are identified for specific milestones that permit performance measurement.

  • A Responsibility Assignment Matrix (RAM) showing the involvement of key contributors to the program.

  • A working schedule prepared with allocated resources showing how these resources will be applied over time to produce the project or service from the program.
  • A Critical Path and Program Evaluation Review Technique that is the basis for all performance reporting, the working schedules, and the known dependencies.

  • A spend plan that shows cash flow throughout the program’s duration.

  • Strengths, Weaknesses as well as Opportunity and Threats (SWOT) analysis with particular attention to program risk.

  • Where risks have been identified, contingency plans have been started to deal with them as well as a risk register to tract the potentials for the risk becoming a problem.

  • If capital equipment is needed in the program, appropriate requisitions have been prepared, with cost justifications attached.

  • The Program plan prepared with participation and/or input from the owners of the deliverables.
    A control system has been established using variance analysis to assess in performance measurement.

  • All components of the program measurement system are in place as defined in the Earned Value Management System description - or an appropriate measure of physical percent complete.

  • Individuals have been selected for assignment to the program whose individual needs will be met through participation, where possible.

  • The program is planned to a manageable level of detail at no less that level 3 of the work breakdown structure (WBS).

  • Work has been broken down into reasonable durations tasks (work packages) which are assigned with a budget and to a responsible Control Account Manager.

  • A post-mortem has been done at each milestone in the program and a final one has been done for the overall program and placed in the program.

  • Members of the team have been instructed to record their working times on the program daily.
    A chart of control accounts (level three of the WBS) has been developed to track earned value against the plan and the contract deliverables of the program.

  • All members of the team are clear on the expectations of them in terms of authority, responsibility and accountability.

  • The standard operating procedures for empowering people has been applied to every member of the team.

  • Limits have been established to determine when the program plan will be revised, such as plus or minus 10% total authorized budget variation, etc.

  • The needs of customers have been carefully considered and documented in preparing the program plan.

  • Qualitative guides have been developed for non-quantifiable program objectives, such as program performance.

  • Checklists have been prepared for major segments of the program so that nothing is overlooked.

Wednesday, August 5, 2009

Ryan Tomayko - How I Explained REST to My Wife

A Blog Post by Ryan Tomayko
Link - http://tomayko.com/writings/rest-to-my-wife

Wife: Who is Roy Fielding?
Ryan: Some guy. He's smart.
Wife: Oh? What did he do?
Ryan: He helped write the first web servers and then did a ton of research explaining why the web works the way it does. His name is on the specification for the protocol that is used to get pages from servers to your browser.
Wife: How does it work?
Ryan: The web?
Wife: Yeah.
Ryan: Hmm. Well, it's all pretty amazing really. And the funny thing is that it's all very undervalued. The protocol I was talking about, HTTP, it's capable of all sorts of neat stuff that people ignore for some reason.
Wife: You mean http like the beginning of what I type into the browser?
Ryan: Yeah. That first part tells the browser what protocol to use. That stuff you type in there is one of the most important breakthroughs in the history of computing.
Wife: Why?
Ryan: Because it is capable of describing the location of something anywhere in the world from anywhere in the world. It's the foundation of the web. You can think of it like GPS coordinates for knowledge and information.
Wife: For web pages?
Ryan: For anything really. That guy, Roy Fielding, he talks a lot about what those things point to in that research I was talking about. The web is built on an architectural style called REST. REST provides a definition of a resource, which is what those things point to.
Wife: A web page is a resource?
Ryan: Kind of. A web page is a representation of a resource. Resources are just concepts. URLs--those things that you type into the browser...
Wife: I know what a URL is..
Ryan: Oh, right. Those tell the browser that there's a concept somewhere. A browser can then go ask for a specific representation of the concept. Specifically, the browser asks for the web page representation of the concept.
Wife: What other kinds of representations are there?
Ryan: Actually, representations is one of these things that doesn't get used a lot. In most cases, a resource has only a single representation. But we're hoping that representations will be used more in the future because there's a bunch of new formats popping up all over the place.
Wife: Like what?
Ryan: Hmm. Well, there's this concept that people are calling Web Services. It means a lot of different things to a lot of different people but the basic concept is that machines could use the web just like people do.
Wife: Is this another robot thing?
Ryan: No, not really. I don't mean that machines will be sitting down at the desk and browsing the web. But computers can use those same protocols to send messages back and forth to each other. We've been doing that for a long time but none of the techniques we use today work well when you need to be able to talk to all of the machines in the entire world.
Wife: Why not?
Ryan: Because they weren't designed to be used like that. When Fielding and his buddies started building the web, being able to talk to any machine anywhere in the world was a primary concern. Most of the techniques we use at work to get computers to talk to each other didn't have those requirements. You just needed to talk to a small group of machines.
Wife: And now you need to talk to all the machines?
Ryan: Yes - and more. We need to be able to talk to all machines about all the stuff that's on all the other machines. So we need some way of having one machine tell another machine about a resource that might be on yet another machine.
Wife: What?
Ryan: Let's say you're talking to your sister and she wants to borrow the sweeper or something. But you don't have it - your Mom has it. So you tell your sister to get it from your Mom instead. This happens all the time in real life and it happens all the time when machines start talking too.
Wife: So how do the machines tell each other where things are?
Ryan: The URL, of course. If everything that machines need to talk about has a corresponding URL, you've created the machine equivalent of a noun. That you and I and the rest of the world have agreed on talking about nouns in a certain way is pretty important, eh?
Wife: Yeah.
Ryan: Machines don't have a universal noun - that's why they suck. Every programming language, database, or other kind of system has a different way of talking about nouns. That's why the URL is so important. It let's all of these systems tell each other about each other's nouns.
Wife: But when I'm looking at a web page, I don't think of it like that.
Ryan: Nobody does. Except Fielding and handful of other people. That's why machines still suck.
Wife: What about verbs and pronouns and adjectives?
Ryan: Funny you asked because that's another big aspect of REST. Well, verbs are anyway.
Wife: I was just joking.
Ryan: It was a funny joke but it's actually not a joke at all. Verbs are important. There's a powerful concept in programming and CS theory called polymorphism. That's a geeky way of saying that different nouns can have the same verb applied to them.
Wife: I don't get it.
Ryan: Well.. Look at the coffee table. What are the nouns? Cup, tray, newspaper, remote. Now, what are some things you can do to all of these things?
Wife: I don't get it...
Ryan: You can get them, right? You can pick them up. You can knock them over. You can burn them. You can apply those same exact verbs to any of the objects sitting there.
Wife: Okay... so?
Ryan: Well, that's important. What if instead of me being able to say to you, "get the cup," and "get the newspaper," and "get the remote"; what if instead we needed to come up with different verbs for each of the nouns? I couldn't use the word "get" universally, but instead had to think up a new word for each verb/noun combination.
Wife: Wow! That's weird.
Ryan: Yes, it is. Our brains are somehow smart enough to know that the same verbs can be applied to many different nouns. Some verbs are more specific than others and apply only to a small set of nouns. For instance, I can't drive a cup and I can't drink a car. But some verbs are almost universal like GET, PUT, and DELETE.
Wife: You can't DELETE a cup.
Ryan: Well, okay, but you can throw it away. That was another joke, right?
Wife: Yeah.
Ryan: So anyway, HTTP--this protocol Fielding and his friends created--is all about applying verbs to nouns. For instance, when you go to a web page, the browser does an HTTP GET on the URL you type in and back comes a web page.
Web pages usually have images, right? Those are separate resources. The web page just specifies the URLs to the images and the browser goes and does more HTTP GETs on them until all the resources are obtained and the web page is displayed. But the important thing here is that very different kinds of nouns can be treated the same. Whether the noun is an image, text, video, an mp3, a slideshow, whatever. I can GET all of those things the same way given a URL.
Wife: Sounds like GET is a pretty important verb.
Ryan: It is. Especially when you're using a web browser because browsers pretty much just GET stuff. They don't do a lot of other types of interaction with resources. This is a problem because it has led many people to assume that HTTP is just for GETing. But HTTP is actually a general purpose protocol for applying verbs to nouns.
Wife: Cool. But I still don't see how this changes anything. What kinds of nouns and verbs do you want?
Ryan: Well the nouns are there but not in the right format.
Think about when you're browsing around amazon.com looking for things to buy me for Christmas. Imagine each of the products as being nouns. Now, if they were available in a representation that a machine could understand, you could do a lot of neat things.
Wife: Why can't a machine understand a normal web page?
Ryan: Because web pages are designed to be understood by people. A machine doesn't care about layout and styling. Machines basically just need the data. Ideally, every URL would have a human readable and a machine readable representation. When a machine GETs the resource, it will ask for the machine readable one. When a browser GETs a resource for a human, it will ask for the human readable one.
Wife: So people would have to make machine formats for all their pages?
Ryan: If it were valuable.
Look, we've been talking about this with a lot of abstraction. How about we take a real example. You're a teacher - at school I bet you have a big computer system, or three or four computer systems more likely, that let you manage students: what classes they're in, what grades they're getting, emergency contacts, information about the books you teach out of, etc. If the systems are web-based, then there's probably a URL for each of the nouns involved here: student, teacher, class, book, room, etc. Right now, getting the URL through the browser gives you a web page. If there were a machine readable representation for each URL, then it would be trivial to latch new tools onto the system because all of that information would be consumable in a standard way. It would also make it quite a bit easier for each of the systems to talk to each other. Or, you could build a state or country-wide system that was able to talk to each of the individual school systems to collect testing scores. The possibilities are endless.
Each of the systems would get information from each other using a simple HTTP GET. If one system needs to add something to another system, it would use an HTTP POST. If a system wants to update something in another system, it uses an HTTP PUT. The only thing left to figure out is what the data should look like.
Wife: So this is what you and all the computer people are working on now? Deciding what the data should look like?
Ryan: Sadly, no. Instead, the large majority are busy writing layers of complex specifications for doing this stuff in a different way that isn't nearly as useful or eloquent. Nouns aren't universal and verbs aren't polymorphic. We're throwing out decades of real field usage and proven technique and starting over with something that looks a lot like other systems that have failed in the past. We're using HTTP but only because it helps us talk to our network and security people less. We're trading simplicity for flashy tools and wizards.
Wife: Why?
Ryan: I have no idea.
Wife: Why don't you say something?
Ryan: Maybe I will.