pan-Internet

ASP.Net: How to bind a drop down list with the names from a Enum

PAN — Fri, 05 Nov 2010 16:33:00 +0000

A ussual way of managing/comunicate between classes is using Enums. This allow you to implement more fast and safe objects that have static values (gender, day of the weeks, months, ...)

Very helpfully is also to bind comboboxes with enumerations; and ... this is simple! In order to bind a combobox with a enumerations values is enough the next code:

cmbEnum.DataSource = Enum.GetNames(typeof(EnumType));

The client get your enum; now to read it is also simple:

EnumType et = (EnumType)Enum.Parse(typeof(EnumType), cmbEnum.SelectedValue);

Simple, elegant and fast!

Good luck!

Example of how to use 2 XMLs and link it using one XSLT file

PAN — Thu, 04 Nov 2010 21:50:00 +0000

In this short article I will present how should be managed the case that two XMLs contains data and you have to link this based on keys and transform into another XML in order to deserialize or read the related entity. For example, if you have a list with prices and a list with products, each list in a separete XML you will have to get each product with his price.

We have 3 files, 2 input XMLs and 1 XSLT.

Inside of the application you will have to apply a transoformation to the XML1 using your XSLT; from inside of XSLT will be called the data from the 2nd XML, called XML1. So, here is the input:

XML1:

<?xml version="1.0" encoding="utf-8"?>
<head>
<zone id="1">
    <content>content 1 |</content>
</zone>
<zone id="2">
    <content>content 2 ||</content>
</zone>
<zone id="3">
    <content>content 3 |||</content>
</zone>
</head>

XML2:

<?xml version="1.0" encoding="utf-8"?>
<pages>
<page idpage="1">
    <content>page 1 |</content>
</page>
<page idpage="2">
    <content>page 2 ||</content>
</page>
<page idpage="3">
    <content>page 3 |||</content>
</page>
</pages>

The transformation file looks like this:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl">
<xsl:output method="xml" indent="yes"/>
<xsl:template match="head">
    <xsl:variable name="pages" select="document('xml2.xml')/pages"/>
    <cap>
      <xsl:for-each select="zone">
        <page>
        <pageid>
          <xsl:value-of select="@id"/>
        </pageid>
        <pagecontent>
          <xsl:value-of select="content"/>
        </pagecontent>
          <xsl:variable name="exid" select="@id"></xsl:variable>
          <outcontent>
            <xsl:value-of select="$pages/page[@idpage=$exid]/content" />
          </outcontent>
        </page>
      </xsl:for-each>
    </cap>
</xsl:template>
</xsl:stylesheet>

As I say we apply the transformation to the XML1 document, getting data from 2nd XML will be solved by the XSLT, so you have to call a transformation to the XML1 from your application (no mather what language are you using). You have to pay attention, to the transformation, ussualy there are settings that doesn't allow to use document method in xslt; to allow this you have to set inside of your program this rule. About how the transformation will happen will see in a future article.

To prove that this is working, I will place here the result of the transformation:

<?xml version="1.0" encoding="utf-8"?>
<cap>
<page>
    <pageid>1</pageid>
    <pagecontent>content 1 |</pagecontent>
    <outcontent>page 1 |</outcontent>
</page>
<page>
    <pageid>2</pageid>
    <pagecontent>content 2 ||</pagecontent>
    <outcontent>page 2 ||</outcontent>
</page>
<page>
    <pageid>3</pageid>
    <pagecontent>content 3 |||</pagecontent>
    <outcontent>page 3 |||</outcontent>
</page>
</cap>

Example of Ajax with jQuery in MVC2

PAN — Wed, 03 Nov 2010 21:18:00 +0000

This is a basic article of how to use the ajax that exists in JQuery in MVC2.

1st of all you should know that you have to include into your page the jQuery framework. If you use telerik controls for MVC this is already there. About the code I have to say that it is functional, and copy-paste here, so as it is in the application.

First step is to implement a Action in your Controller:

        [AcceptVerbs( HttpVerbs.Get)]
        public JsonResult GetSeasons(int divisionId)
        {
            var v = StagesBL.ListSeasons4Division(divisionId);
            return Json(v, JsonRequestBehavior.AllowGet);
        }

What I return is a list of objects (ViewModels). Using this action I implement the next javascript that:

This is enough for binding a dropdownlist (ddlSes) based on a another dropdownlist change event (ddlDiv).

Hoping that this will help I have to say that I am avaible to help!

Web Crawler

PAN — Tue, 19 Oct 2010 04:53:00 +0000

Imagine a world where you can see some data in a place and after 5 minutes that data should be yours. Imagine that all you have to do is to describe that data and to tell to a software something like this "I want this, there". And there can be a database, a excel file, or simple, a text file; or a XML; or a CSV; or your specifyed format!

This will be posible soon, with our new product in the data collecting domain. No more people to work for you on this job. No more "Hard work" or high tehnology requered. Just some clicks and you are there, with the needed data in your hand.

Where you can use it? in various domains:

1. Imagine that you have a second-hand car ads site, for clients; Now you find a good client who is ready to pay good money for having his ads on your site. What you will do ...? copy-paste each ad? Not a good solution. Is more simple with my product.

2. Imagine that you are looking for a house. Ussualy the real estate sites doesn't offer good comparation tools for comparing the ads. What if you will have that ads into a excel file where you can sort, order, filter that ads? it would be a little more nice.

3. You have sites. In diferent domains. Grabbing data from users is a little dificulty. What you need is our tool. It can increase your content very easy!

RSS reader

PAN — Mon, 16 Aug 2010 21:32:00 +0000

We are happy to announce that our 1st product, an RSS Reader application built in ASP.NET MVC2 called PAN RSS is avaible for tests on feed-box.com (in romanian language). The application has succesflly pas a important test made by GoogleBot - see the image below - we run with a very good response from server the application for more than 20,000 request in 1 day (that means a request every 4,32 seconds).

In order to have a "premium" solution as a RSS reader we try to develop it to work as performant is posible. In the current solution there are a small number of features but this is for tests, for feedback from clients and users (we are waiting and from you), a complete list with the features of this application will be published in the moment when a beta solution will be avaible for user. Current features include RSS feed readers, SEO features and a complete admin solution; we are working for themes support (including mobile version).

In order to perform better and better we need FEEDBACK from you; please test the solution - feed-box.com - and send your sugestion to us (here, in comments, in the web application on contact page, anywhere, no mather). pan-Internet promise that all good sugestion will be considered.

Are you interested about this solution? About comercial edition? Contact us with this in order to receive more details.

Enjoy and don't forget about feedback!

Sql optimizations - subqueries

PAN — Mon, 26 Jul 2010 06:16:00 +0000

Problem: in mssql, to insert into a destination table, data from a source table - only data that is not already inserted.

1st solution, a simple query like [1]; but when you have to run for more data, this will go bad. And here is the solution:

When using querys in anotherr query, a good ideea in order to made a opitmized query is to use in subquery what you have to process, not what you want to exclude:

[1] Wrong:

insert into table_destination select * from table_source where identifierfield not in (select identifierfield from table_destination)

[2] To corect this, you have to change somehow the expression "where identifierfield not in" into a expression like "where identifierfield in". So, the optimized way of this query should look like:

insert into table_destination select * from table_source where identifierfield in (select identifierfield from table_source s left join table_destination d on d.identifierfield = s.identifierfield where d.identifierfield is null)

Ping - all about ping command. Ping-Pong!

PAN — Sun, 14 Mar 2010 21:45:00 +0000

Ping is a important computer network administration utility; this tool is used to test whether a particular host is reachable across an Internet Protocol (IP) network and it measure the round-trip time for packets sent from the local host to a destination computer [including the local host's own interfaces]. When using this utility from pan-internet.com your "localhost" become our web server; this feature (changing the IP for where you send the ping) is very helpfully when you need to see from where is coming the reply of a computer. An example in this way is pinging a domain what has been changed the name server - untill replication is done requests to this domain will reply from diferent servers (old server or new server).

How ping operates. It happens by sending Internet Control Message Protocol (ICMP) echo request packets to the target host and waits for an ICMP response (casually called a pong). The ping process measures the round-trip time and records any packet loss. Usually results of the test are printed in form of a statistical summary of the response packets received, including the minimum, maximum, and the mean round-trip times; sometimes there is included and the standard deviation of the mean.

The use of the ping utility is usually described as pinging a host computer but there are various command line options [diferent on each operating system] that enable special operational modes, such as to specify the packet size used as the probe, automatic repeated operation for sending a specified count of probes, time stamping options, or to perform a Flood pinging attention with this, it may be considered as a simple form of denial-of-service attack (you overwhelm the destination/victim with ICMP echo request packets).

Ping-Pong command history. The 1st ping tool was wroted by Mike Muuss in December 1983; it was used to troubleshoot problems in an Internet Protocol network. The name of that program was inspired by the pulses of sound made by a sonar [the operation is analogous to a sonar in submarines]. A big step was done in 2003 when a number of Internet service providers began filtering out ICMP Type 8 (ICMP Echo Request) messages at their network boundaries, considering this as unusefull as a result of the increasing use of ping for target reconnaissance -a example of abusing of ping is some worms such as Welchia that flood the Internet with ping requests in order to locate new computers to infect. The abuse of ping command affects the networks, not only did the availability of ping responses; it added to the overall load on networks and this cause problems for routers across the Internet. Although RFC 1122 prescribes that any host must accept an echo-request and issue an echo-reply in return but hosts that no longer follow this standard are frequent on the public Internet.

ICMP packet

Internet Control Message Protocol packet for ping consist of header (yellow) that contains the protocol and type service, the payload (blue - contains the type of ICMP message, code, checksum, Quenc - here the ICMP echo message, data - a arbitrary length packet). ***ICMP, including ping resides on network layer (the same level as IP - level 3) - that means that ping doesn't use a port for communication.

Ping command is used and in other domains like gaming where the game test the network by sending some ping command and give to the player some informations regarding the experience of gaming what comes.

The term of ping is used to test a feature avaibility. Ussualy this are diferent by the original ping command but the functionality is similar (the sonar): using ping to test if a service is avaible by sending a query to it - requesting a web page to see if the web server is avible, executing a simple sql query to see if the database serve is working properly, or asking information from diferent instant messaging systems to see if a person is conected

How do I change my IP address?

PAN — Sun, 14 Mar 2010 21:42:00 +0000

The Internet Protocol (IP) address is a number assigned in order to establish the communication between your computer/machine and the network. Ussualy you will need to change the IP address when you get a network conflict or other netwoek related issue, when you need a specific IP address or range (some applications ask this); change of the IP address is used and when you need to protect yourself from other users/programs-viruses.

For changing the IP address you have to know some basic things like what is a static IP (this means that you are the owner of that IP, you don't share it with somebody else) address or a dynamic IP address(this happens in a network where you have an address that can be changed automatically - when you connect to network you get password X but on other session you will get an Y IP address and X will be assigned to sombody else).

Change te IP address when you use a dial-up/PPPoE can be done by disconecting and reconecting to the network.

When you are using modem/DSL/FTTH connection, the IP is setup as a static IP based on your MAC address. In this case you have to request a IP change from your ISP (Internet Service Provider).

In order to change the IP address you have to access your IP machine settings. This happens diferent for every operating system. The basic stuff is to get to the IP address settings:

Windows 2000/XP -Start>Controll Panel>Network Connections>Local area network>Properties>Internet Protocol (TCP/IP)
Windows 9x/Milenium - Start>Control Panel>Network>Network card>TCP/IP>IP address
for Linux users - access /etc/sysconfig/network directory and there edit the interfaces and adjust settings.

and there to change the IP address/subnet mask/gateway.

Note that the IP address cann't be changed from outside of your network; that means after you change the IP, your security [ussualy] increase.

Other methods for changing the IP address is to use a proxy, but this is subject of another article, it is diferent.

i3Theme vPan - final version for BlogEngine.Net 1.6.0.0

PAN — Sun, 14 Mar 2010 21:37:00 +0000

This is the finall version of i3Theme, builded for BlogEngine 1.6.0.0.

You can get it from here: pan-internet.com > blogengine.net > themes > i3Theme vPan.zip

What is fixed is the tag cloud (the diference is that last time there was some problems regarding the design of this widget.

Enjoy it!

Is working? Is down or up?

PAN — Sat, 06 Mar 2010 17:46:00 +0000

What is the stautus of a computer? What about my site, why I cann't load it? What about my visitors? What they are seeing? Just some reasons to use ping, from your computer and from pan-Internet.com application.

A simple way to see if a comuter is working: send ping command. This can be done from your operating system, or from a web application like pan-Internet using ping application from pan Internet.

You can send ping to a IP address (example ping 127.0.0.1 is sending a ping to your own computer using loopback interface), ping to a domain (example ping pan-internet.com is sending a ping command to the server where this site is hosted); also for sending ping to your computer you can use ping localhost - this is the same as ping 127.0.0.1. The result of the ping, called response can tell to you how is your connection with the machine where you have sent ping - time that was necesary for receiving the response, the percent of lost data in this command show you how you can comunicate with that machine.

Also the ping command can be used with some parameters that will modify the behaviour of this command; on ping application you can see the complete tehnical details of this command. For example, if you need to test the behavior of a server, you can send the ping command continously, but be carefully, this can be considered a attack by the firewall and can block your connection with the server:

panInternet Ping application send pings without parameters. Just simple pings;to use parameters I recomand to you to use your windows/linux command line, from there you have a lot of options for sending ping.