CompuOnline.info

New blog in Dutch

2011-02-18T06:43:00.000-08:00

I just started a blog in Dutch about the making of websites. The blog is mainly meant for people who are looking to get a website build and need more information on how to go about it. This new blog can be found here: www.uwwebsitelatenmaken.com

Installing Passenger on CentOS (NGINX)

2010-09-27T12:51:00.000-07:00

Installing passenger on CentOS doesn't seem to be documented on the Passenger website, so here is a small instruction.

If you don't have rails installed, install it first:
http://www.compuonline.info/2010/09/installing-ruby-on-rails-on-centos.html

Installing passenger:
$ yum -y install apr-devel gcc-c++ openssl-devel zlib-devel
$ gem install passenger
$ passenger-install-nginx-module

and follow the instructions.

Installing Ruby on Rails on CentOS

2010-09-27T12:31:00.001-07:00

Although it seems to be a bit difficult to find good information on how to install Rails on CentOS, it is not hard at all. Some sites compile everything from source, but that seemed a lot of work to me. I decided to use the Ruby Version Manager (RVM) instead.

If you don't have GIT installed, install it first:
$ yum install git

Next, we can install RVM:
$ bash < <( curl http://rvm.beginrescueend.com/releases/rvm-install-head )

Now we have RVM we can install Ruby with one command:
$ rvm install ruby 1.9.2

With Ruby installed, we can use Ruby Gems to install rails:
$ gem install rails

Wordpress: Stop asking for FTP details

2010-07-15T09:54:00.001-07:00

I had an issue with Wordpress asking for FTP details when installing or updating a plugin. This is quite annoying, so I tried to find a good solution. The solution I mostly found was storing the FTP login details in the PHP configuration file. I prefer not to use FTP at all though, luckily I found this plugin: http://cdn.yoast.com/wp-content/uploads/2009/02/fix-plugin-update.zip

This plugin makes sure Wordpress no longer requires the owner of the plugin files to be the same as the user the web server is running under. You will still need to make sure your web server can write to the plugin directory.

Source: http://yoast.com/fix-automatic-plugin-update/

Wordpress: Disable plugin in Database

2010-06-27T15:38:00.000-07:00

Sometimes a plugin causes Wordpress to stop working, including the admin interface. Luckily it is possible to disable plugins from the database, so you can access the Worldpress admin interface again.

Use this code the locate the field that need to be modified:


SELECT * FROM wp_options WHERE option_name = 'active_plugins';

To disable all plugins, just remove all code in the field.

Hobofields - undefined method fields for

2010-05-13T18:33:00.000-07:00

If you are trying to use the most recent Hobofields you may get the error "undefined method `fields' for ...". This problem can be solved by adding


config.gem 'hobofields'

to the config/environment.rb file.

Installing Cassandra on CentOS

2010-03-26T19:09:00.000-07:00

Cassandra is an interesting distributed database system based on the ideas of Bigtable and Dynamo. So let's give it a try. We will make a single node setup for now.

The installation of Cassandra on CentOS is not that complicated, but there are some small things you need to know to get it working.

First of all Java needs to be installed to run Cassandra, as it is completely writen in Java. Installing Java with yum is quite easy, just enter:

# yum install java-1.6.0-openjdk.i386 (for 32-bit systems)
or
# yum install java-1.6.0-openjdk.x86_64 (for 64-bit systems)

Next download the latest binary from the the Cassandra website:
http://cassandra.apache.org/download/

Unless you are setting up a production server, you can go for the beta release. An example of the download command:

# wget http://apache.ziply.com/cassandra/0.6.0/apache-cassandra-0.6.0-beta3-bin.tar.gz
(change the url to the latest version)

Now we need to uncompress the downloaded file:
tar -zxvf apache-cassandra-0.6.0-beta3-bin.tar.gz
(change the file name if you have a newer version of Cassandra)

Unfortunately the 0.6.0 release doesn't come with all dependencies, so we will need to install them manually:

* Log4J (download), from the archive copy the log4j-x.x.x.jar file into the /lib folder of Cassandra
* Google Collections (download), from the archive copy the google-collect.x.x.jar into the /lib folder of Cassandra
* Apache Commons Collections (download), from the archive copy the commons-collections-x.x.x.jar into the /lib folder of Cassandra
* Apache Commons Lang (download), from the archive copy the commons-lang-x.x.jar into the /lib folder of Cassandra
* SLF4J (download), from the archive copy the slf4j-api-x.x.x.jar and slf4j-log4jxx-x.x.x.jar into the /lib folder of Cassandra
* Apache Commons CLI (download), from the archive copy the commons-cli-x.x.jar into the /lib folder of Cassandra
* jLine (download), from the archive copy the jline-x.x.xx.jar into the /lib folder of Cassandra

Now we need to make some directories required by Cassandra:
# sudo mkdir -p /var/log/cassandra
# sudo mkdir -p /var/lib/cassandra

Last before starting it up, we have to check the config file:
# joe conf/storage-conf.xml (you can use another editor than joe if you like)

In the config file make sure that all paths mentioned exist, and fill the correct ip addresses where needed.

That should be all and we can now start Cassandra:
# bin/cassandra -f

And to see if it really works (assuming you don't seen any ugly error messages):
# bin/cassandra-cli --host localhost --port 9160

This start the client and we can try some commands:

cassandra> set Keyspace1.Standard2['jsmith']['first'] = 'John'
cassandra> set Keyspace1.Standard2['jsmith']['last'] = 'Smith'
cassandra> set Keyspace1.Standard2['jsmith']['age'] = '42'
cassandra> get Keyspace1.Standard2['jsmith']

After this you should see the results of the records inserted being shown back from the database.

Rails: Don't render layout for ajax calls

2009-09-21T10:19:00.000-07:00

With one simple line of code you prevent layouts from being loaded for Ajax calls. Just add this line to your application controller of you Ruby on Rails project:




layout proc{ |c| c.request.xhr? ? false : "application" }

VB6 fill form IE

2009-06-12T06:20:00.000-07:00

This is a repost of an example many people were looking for.

In this sample I will fill the altavista search box, with the WebBrowser control. Below I will list some subs and functions which are used in this sample.

Open a new project (standard exe) and place a WebBrowser control, a textbox, and a command button on form1. Make sure you also have an reference to mshtml.tlb.

Add the following code to form1:


Private Sub Command1_Click()
Dim doc As HTMLDocument

'go to the altavista (text) search page
WebBrowser1.Navigate "http://www.altavista.com/cgi-bin/query?text"

'Wait until page is loaded
Do
DoEvents
Loop Until Not WebBrowser1.Busy

'Make doc reference to the document inside the webbrowser control
Set doc = WebBrowser1.Document

'Set field q with the value of Text1
SetInputField doc, 0, "q", Text1

'Submit the form (same result as click the search button)
doc.Forms(0).submit

'Wait until result are loaded
Do
DoEvents
Loop Until Not WebBrowser1.Busy

MsgBox "Altavista search result loaded"
End Sub

Add the following code to a module:


Public Sub SetInputField(doc As HTMLDocument, Form As Integer, Name As String, Value As String)
'doc = HTMLDocument, can be retrieved from webbrowser --> webbrowser.document
'Form = number of the form (if only one form in the doc --> Form = 0)
'Name = Name of the field you would like to fill
'Value = The new value for the input field called name
'PRE: Legal parameters entered
'POST: Input field with name Name on form Form in document doc will be filled with Value

For q = 0 To doc.Forms(Form).length - 1
If doc.Forms(Form)(q).Name = Name Then
doc.Forms(Form)(q).Value = Value
Exit For
End If
Next q
End Sub

Additional useful subs:


Sub to get the contents from a textbox:
Public Function GetInputField(doc As HTMLDocument, Form As Integer, Name As String) As String
For q = 0 To doc.Forms(Form).Length - 1
If doc.Forms(Form)(q).Name = Name Then
GetInputField = doc.Forms(From)(q).Value
Exit For
End If
Next q
End Function



Sub to set a Checkbox:
Public Sub SetCheckBox(doc As HTMLDocument, Form As Integer, Name As String, Value As Boolean)
For q = 0 To doc.Forms(Form).Length - 1
If doc.Forms(Form)(q).Name = Name Then
doc.Forms(From)(q).Checked = Value
Exit For
End If
Next q
End Sub



Sub set a radio button:
Public Sub SetRadioButton(doc As HTMLDocument, Form As Integer, Name As String, Name2 As String)
For q = 0 To doc.Forms(Form).Length - 1
If (doc.Forms(Form)(q).Name = Name) And (doc.Forms(Form)(q).Value = Name2) Then
doc.Forms(From)(q).Checked = True
Exit For
End If
Next q
End Sub


Sub set a combo box:
Public Function SetComboBoxValue(ByVal doc As IHTMLDocument3, Form As
Integer, Name As String, Name2 As String)
'**** This one bases it's selection on the Value of the - - Tag.
Dim q, i

For q = 0 To doc.Forms(Form).length - 1
If (doc.Forms(Form)(q).Name = Name) Then
For i = 0 To doc.Forms(Form)(q).length - 1
If doc.Forms(Form)(q).Options(i).Value = Name2 Then
doc.Forms(Form)(q).Options(i).Selected = True
Exit For
End If
Next i
End If
Next q
End Function


Public Function SetComboValue(ByVal doc As IHTMLDocument3, Form As Integer,
Name As String, Name2 As String)
'**** This one bases it's selection on the Value of the Text after the -
'Text - Tag.
Dim q, i

For q = 0 To doc.Forms(Form).length - 1
If (doc.Forms(Form)(q).Name = Name) Then
For i = 0 To doc.Forms(Form)(q).length - 1
If doc.Forms(Form)(q).Options(i).Text = Name2 Then
doc.Forms(Form)(q).Options(i).Selected = True
Exit For
End If
Next
End If
Next q

Rails - HoboFields as Plugin

2009-06-11T09:19:00.000-07:00

As I mentioned before, the documentation of Hobo is still not sufficient to build a real application with Hobo. One of the problems I encountered was that I wanted to change how certain fields are displayed in the new/edit form. The documentation does not describe this clearly or at all (I couldn't find it). For this Hobo is not really usable for me at this moment. One think I really like about Hobo is HoboFields though. HoboFields allows you to declare your table definitions in your model and automatically generate migrations from it. The good news is that we can actually use HoboField without using the complete Hobo package as it's available as plugin.

When HoboFields is installed you can do the following:


require 'hobo_fields' 

class Category < ActiveRecord::Base
  fields do
    name  :string
    description :text
    timestamps
  end

   belongs_to :category
   belongs_to :administration
end

Next, you just run:


ruby script/generate hobo_migration

And the migration will be generated. Now you may think that this is not a good thing, because by making your own migrations you could keep track of changes and roll updates to other environments, right? Well, this is not a problem because HoboFields will actually detect any changes made to the model and generate the migrations for you!

If you are interested in using HoboFields, you can install it as follows:


gem install hobofields

The else if in Ruby

2009-06-05T07:09:00.000-07:00

The basic if structure in ruby looks like listed below. Especially the 'else if' is uncommon: elsif.


if name=='peter'
  ...
elsif name=='john'
  ...
end

Rails & Hobo: Changing the default layout

2009-06-03T16:52:00.000-07:00

According to the POD tutorial on the Hobo project website you should be able to change the default layout of the page in app/views/taglibs/application.dryml. This is true, however the example they give does not work (any more):



  
    Copyright 2009 XFerion

After some searching though the code generated by Hobo I found out how one can make this work with the current version of Hobo:



  
 Copyright 2009 XFerion

Ruby on Rails - Hobo

2009-06-03T16:38:00.000-07:00

Hobo is a framework for Ruby on Rails which is supposed to make the development of a web application even easier. I just tried it and it seems to have some great features to get an application working really fast. This project has one big downside as of now, the documentation is terrible. I hope soon there will be some more documentation available, as it hard to find out how everything works. There are some tutorials available but unfortunately they of some parts that have not been updated to the latest version of Hobo, with the result that some of the examples don't work.

I really hope they will get some good documentation online soon, as the project seems to be very promising. Even though the final 1.0 version of this project is not completed yet, I will give it a try for my next project. Hopefully they will also add the support for internationalization soon as that would be a really nice addition to this framework for the non US people out there like me.

You can find the Hobo project here: Ruby on Rails Hobo framework website

Try Catch Finally block in Ruby

2009-04-29T09:56:00.000-07:00

For all the people with bad memory like me, here is the Ruby equivalent of the Try Catch Finally block:


begin
  somecode()
rescue
  puts "Error #{$!}"
ensure 
  this_code_will_execute_always()
end

Ruby on Rails 2.0 Scaffold

2009-04-29T06:29:00.000-07:00

The scaffold generator is not as easy to use anymore in Rails 2.0 as it was in the previous version. Instead of working directly with database tables, now it only works with migrations. The use of migrations is a good thing in my opinion, because migrations keep it easy to track and apply database changes. What I don't like about the renewed scaffold generator is that you have to put all the fields you want to have in your table in the command line. If you create your own migration files, scaffold simply doesn't work. This may be OK with small tables, but if you have tables with lots of fields it is much easier to make the migration file your self. Putting all table fields on the command line doesn't give a good view of all the fields, and you won't notice if you forgot a field.

An example of a scaffold generation:


> ./script/generate scaffold ModelName field1:type field2:type field3:type

Add Table Fields with Rails Migrations

2009-04-29T06:00:00.000-07:00

With Ruby on Rails you van easily add columns to an existing database table using migrations. The update can than automatically be applied to the different environments (i.e. development, test, production).

The code for the migration is as follows:


  class AddAdministrationsMyclientsidBlocked < ActiveRecord::Migration
    def self.up
      add_column :administrations, :myclient_id, :integer
      add_column :administrations, :blocked, :boolean, :default => false

    end

    def self.down
      remove_column :administrations, :myclient_id
      remove_column :administrations, :blocked
    end
  end

HTML Escape Characters: The complete list

2009-04-27T08:47:00.000-07:00

Below you will find a complete list of HTML escape characters:

Symbol	Code	Entity Name
€		€
Space
!	!
"	"	"
#	#
$	$
%	%
&	&	&
'	'
(	(
)	)
*	*
+	+
,	,
-	-
.	.
/	/
0	0
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
:	:
;	;
<	<	<
=	=
>	>	>
?	?
@	@
A	A
B	B
C	C
D	D
E	E
F	F
G	G
H	H
I	I
J	J
K	K
L	L
M	M
N	N
O	O
P	P
Q	Q
R	R
S	S
T	T
U	U
V	V
W	W
X	X
Y	Y
Z	Z
[	[
\	\
]	]
^	^
_	_
`	`
a	a
b	b
c	c
d	d
e	e
f	f
g	g
h	h
i	i
j	j
k	k
l	l
m	m
n	n
o	o
p	p
q	q
r	r
s	s
t	t
u	u
v	v
w	w
x	x
y	y
z	z
{	{
\|	\|
}	}
~	~
Non-breaking space
¡	¡	¡
¢	¢	¢
£	£	£
¤	¤	¤
¥	¥	¥
¦	¦	¦
§	§	§
¨	¨	¨
©	©	©
ª	ª	ª
«	«
¬	¬	¬

®	®	®
¯	¯	¯
°	°	°
±	±	±
²	²	²
³	³	³
´	´	´
µ	µ	µ
¶	¶	¶
·	·	·
¸	¸	¸
¹	¹	¹
º	º	º
»	»	»
¼	¼	¼
½	½	½
¾	¾	¾
¿	¿	¿
À	À	À
Á	Á	Á
Â	Â	Â
Ã	Ã	Ã
Ä	Ä	Ä
Å	&#197	Å
Æ	Æ	Æ
Ç	Ç	Ç
È	È	È
É	É	É
Ê	Ê	Ê
Ë	Ë	Ë
Ì	Ì	Ì
Í	Í	Í
Î	Î	Î
Ï	Ï	Ï
Ð	Ð	Ð
Ñ	Ñ	Ñ
Ò	Ò	Ò
Ó	Ó	Ó
Ô	Ô	Ô
Õ	Õ	Õ
Ö	Ö	Ö
×	×	×
Ø	Ø	Ø
Ù	Ù	Ù
Ú	Ú	Ú
Û	Û	Û
Ü	Ü	Ü
Ý	Ý	Ý
Þ	Þ	Þ
ß	ß	ß
à	à	à
á	á	á
â	â	â
ã	ã	ã
ä	ä	ä
å	å	å
æ	æ	æ
ç	ç	ç
è	è	è
é	é	é
ê	ê	ê
ë	ë	ë
ì	ì	ì
í	&#237	í
î	î	î
ï	ï	ï
ð	ð	ð
ñ	ñ	ñ
ò	ò	ò
ó	ó	ó
ô	ô	ô
õ	õ	õ
ö	ö	ö
÷	÷	÷
ø	ø	ø
ù	ù	ù
ú	ú	ú
û	û	û
ü	ü	ü
ý	ý	ý
þ	þ	þ
ÿ	ÿ
Ā	Ā
ā	ā
Ă	Ă
ă	ă
Ą	Ą
ą	ą
Ć	Ć
ć	ć
Ĉ	Ĉ
ĉ	ĉ
Ċ	Ċ
ċ	ċ
Č	Č
č	č
Ď	Ď
ď	ď
Đ	Đ
đ	đ
Ē	Ē
ē	ē
Ĕ	Ĕ
ĕ	&#277
Ė	Ė
ė	ė
Ę	Ę
ę	ę
Ě	Ě
ě	ě
Ĝ	Ĝ
ĝ	ĝ
Ğ	Ğ
ğ	ğ
Ġ	Ġ
ġ	ġ
Ģ	Ģ
ģ	ģ
Ĥ	Ĥ
ĥ	ĥ
Ħ	Ħ
ħ	ħ
Ĩ	Ĩ
ĩ	ĩ
Ī	Ī
ī	ī
Ĭ	Ĭ
ĭ	ĭ
Į	Į
į	į
İ	İ
ı	ı
Ĳ	Ĳ
ĳ	ĳ
Ĵ	Ĵ
ĵ	ĵ
Ķ	Ķ
ķ	ķ
ĸ	ĸ
Ĺ	Ĺ
ĺ	ĺ
Ļ	Ļ
ļ	ļ
Ľ	&#317
ľ	ľ
Ŀ	Ŀ
ŀ	ŀ
Ł	Ł
ł	ł
Ń	Ń
ń	ń
Ņ	Ņ
ņ	ņ
Ň	Ň
ň	ň
ŉ	ŉ
Ŋ	Ŋ
ŋ	ŋ
Ō	Ō
ō	ō
Ŏ	Ŏ
ŏ	ŏ
Ő	Ő
ő	ő
Œ	Œ
œ	œ
Ŕ	Ŕ
ŕ	ŕ
Ŗ	Ŗ
ŗ	ŗ
Ř	Ř
ř	ř
Ś	Ś
ś	ś
Ŝ	Ŝ
ŝ	ŝ
Ş	Ş
ş	ş
Š	Š
š	š
Ţ	Ţ
ţ	ţ
Ť	Ť
ť	&#357
Ŧ	Ŧ
ŧ	ŧ
Ũ	Ũ
ũ	ũ
Ū	Ū
ū	ū
Ŭ	Ŭ
ŭ	ŭ
Ů	Ů
ů	ů
Ű	Ű
ű	ű
Ų	Ų
ų	ų
Ŵ	Ŵ
ŵ	ŵ
Ŷ	Ŷ
ŷ	ŷ
Ÿ	Ÿ
Ź	Ź
ź	ź
Ż	Ż
ż	ż
Ž	Ž
ž	ž
ſ	ſ
Ŕ	Ŕ
ŕ	ŕ
Ŗ	Ŗ
ŗ	ŗ
Ř	Ř
ř	ř
Ś	Ś
ś	ś
Ŝ	Ŝ
ŝ	ŝ
Ş	Ş
ş	ş
Š	Š
š	š
Ţ	Ţ
ţ	ţ
Ť	Ť
ť	Ɂ
Ŧ	Ŧ
ŧ	ŧ
Ũ	Ũ
ũ	ũ
Ū	Ū
ū	ū
Ŭ	Ŭ
ŭ	ŭ
Ů	Ů
ů	ů
Ű	Ű
ű	ű
Ų	Ų
ų	ų
Ŵ	Ŵ
ŵ	ŵ
Ŷ	Ŷ
ŷ	ŷ
Ÿ	Ÿ
Ź	&#377
ź	ź
Ż	Ż
ż	ż
Ž	Ž
ž	ž
ſ	ſ

Ruby On Rails: end_form_tag removed in Rails 2.0

2009-04-27T08:38:00.000-07:00

The end_form_tag method is removed in Rails 2.0, now one can create a block to start and end a HTML form. This is actually quite simple:


<% form_tag :action => 'create' do %>
#...
<% end %>

An important part is the 'do' at the end of the form_tag line.

Ruby On Rails: Write to log

2009-04-27T08:30:00.000-07:00

A good thing about Rails is the logs that are produced. In development mode rails will list out all SQL statements and trace all controller calls.

It is possible to add custom messages to the Rails log through in a single line command. The RAILS_DEFAULT_LOGGER object, which is defined in environment.rb, makes this possible.

The RAILS_DEFAULT_LOGGER object supports the following log levels:
* debug
* info
* warn
* error
* fatal

To add debug calls to your code for development mode just add the following:


RAILS_DEFAULT_LOGGER.info "Your log message"

Rails Migration Types

2009-03-25T10:36:00.000-07:00

I started to work with Ruby on Rails again, and I noticed that lots of things changed with Rails 2.0. Mostly good things if you get the hang of it. Only to bad old applications need lots of adjustments. One new thing I learned (probably was possible before) is Rails Migrations. At first it didn't seem so useful, but it is actually is. You can generate and update your database completely with migrations, this also means that you can easily switch your DBMS. Which is a really nice feature. Another big pro is the ability to keep easily track of the database changes en easily update different environments (i.e. from development to test and production).

Here a list of Rails Migration Types mapped to MySQL Column Data Types:

Rails Migration Symbol	MySQL Data Type
t.binary	blob
t.boolean	tinyint(1)
t.date	date
t.datetime	datetime
t.decimal	decimal
t.float	float
t.integer	int(11)
t.string	varchar(255)
t.text	text
t.time	time
t.timestamp	datetime

VB.NET: File.Copy error: The specified network name is no longer available.

2008-11-28T03:39:00.000-08:00

Today I had a strange problem with a VB.NET program I made some time ago. It simply copies some file from a Windows Server 2003 share to a Windows XP client. Suddenly it didn't work any more, giving the following error: System error 64 has occurred. The specified network name is no longer available. This seemed to happen on a large file.

After some searches I found out that this problem is not really in VB.NET, but actually is an error in Windows Server. It can be fixed with a small registry change on the server. Please see http://support.microsoft.com/kb/892100/en-us for details.

VB.NET: Sign PDF in Visual Basic .NET

2008-11-14T02:42:00.000-08:00

There are lots of expensive components out there to sign PDF files from your program, but what if you could do it for free? Below you will find my VB.NET code to sign a PDF file with your own PKCS 12 certificate. If you added the classes below to your project, signing a PDF file will become this simple:


Dim signer As New PdfSigner("[your certificate.pfx]", "[your certificate password]", meta)
signer.SignPdf("[your pdf file]", sPdfFile)

It couldn't be much easier right? Please also check the PdfSigner parameters for additional options. The following classes make use of the completely free iTextSharp library, that is available here. And now finally the classes:


Imports iTextSharp.text
Imports iTextSharp.text.pdf
Imports System.IO

' 
' This class signs pdf files
' 

Public Class PdfSigner
    Public Enum enumCertification
        NOT_CERTIFIED = 0
        CERTIFIED_NO_CHANGES_ALLOWED = 1
        CERTIFIED_FORM_FILLING = 2
        CERTIFIED_FORM_FILLING_AND_ANNOTATIONS = 3
    End Enum

    Public Structure structSigMetaData
        Dim sReason As String
        Dim sContact As String
        Dim sLocation As String
    End Structure


    Protected pdfMetaData As PdfMetaData
    Protected certificate As Certificate

    Public sLastError As String = ""
    Public bMultipleSignatures As Boolean = False
    Public bSignatureStamp As Boolean = False
    Public Certification As enumCertification = enumCertification.CERTIFIED_NO_CHANGES_ALLOWED
    Public SignatureMetaData As structSigMetaData
    Public sSigImageFile As String = ""

#Region "Contructors"
    Public Sub New(ByVal certificate As Certificate, Optional ByVal sPassword As String = "", Optional ByVal PdfMetaData As PdfMetaData = Nothing)
        If IsNothing(PdfMetaData) Then PdfMetaData = New PdfMetaData

        Me.pdfMetaData = PdfMetaData
        Me.certificate = certificate

        Me.SignatureMetaData.sReason = ""
        Me.SignatureMetaData.sContact = ""
        Me.SignatureMetaData.sLocation = ""
    End Sub

    Public Sub New(ByVal sCertificateFile As String, Optional ByVal sPassword As String = "", Optional ByVal PdfMetaData As PdfMetaData = Nothing)
        If IsNothing(PdfMetaData) Then PdfMetaData = New PdfMetaData

        Me.pdfMetaData = PdfMetaData
        Me.certificate = New Certificate
        Me.certificate.LoadCertificate(sCertificateFile, sPassword)

        Me.SignatureMetaData.sReason = ""
        Me.SignatureMetaData.sContact = ""
        Me.SignatureMetaData.sLocation = ""
    End Sub
#End Region

#Region "Functions"
    ' 
    ' Sign the sInFile and write the signed file to sOutFile
    ' 

    Public Function SignPdf(ByVal sInFile As String, ByVal sOutFile As String) As Boolean
        Dim st As PdfStamper
        Dim fs As FileStream
        Dim iWidth As Integer = 150
        Dim iHeight As Integer = 150

        Try
            'Check if the input file exist
            If Not File.Exists(sInFile) Then
                Me.sLastError = "The input file " & sInFile & " does not exist"
                Return False
            End If

            Dim reader As PdfReader = New PdfReader(sInFile)
            fs = New FileStream(sOutFile, FileMode.Create, FileAccess.Write)
            If Me.bMultipleSignatures Then
                st = PdfStamper.CreateSignature(reader, fs, Chr(0), Nothing, True)
            Else
                st = PdfStamper.CreateSignature(reader, fs, Chr(0))
            End If

            st.MoreInfo = Me.pdfMetaData.MetaData
            st.XmpMetadata = Me.pdfMetaData.GetMetaDataXmp


            Dim sap As PdfSignatureAppearance = st.SignatureAppearance
            sap.CertificationLevel = Me.Certification
            sap.SetCrypto(Me.certificate.akp, Me.certificate.chain, Nothing, PdfSignatureAppearance.WINCER_SIGNED)

            sap.Reason = Me.SignatureMetaData.sReason
            sap.Contact = Me.SignatureMetaData.sContact
            sap.Location = Me.SignatureMetaData.sLocation

            If Me.sSigImageFile <> "" Then
                If Not File.Exists(Me.sSigImageFile) Then
                    Me.sLastError = "The image file " & Me.sSigImageFile & " does not exist"
                    Return False
                End If

                Dim img As System.Drawing.Image = System.Drawing.Image.FromFile(Me.sSigImageFile)
                sap.Image = Image.GetInstance(img, img.RawFormat)
                iWidth = img.Width
                iHeight = img.Height
            End If

            If Me.bSignatureStamp Then
                sap.SetVisibleSignature(New iTextSharp.text.Rectangle(100, 100, 100 + iWidth, 100 + iHeight), 1, Nothing)
            End If

            Return True
        Catch ex As Exception
            Me.sLastError = ex.Message
            Return False
        Finally
            Try
                If Not IsNothing(st) Then st.Close()
            Catch
            End Try
        End Try
    End Function
#End Region

End Class


Imports System.IO

Imports Org.BouncyCastle.X509
Imports Org.BouncyCastle.Crypto
Imports Org.BouncyCastle.Pkcs

' 
' This class hold the certificate and extract private key needed for e-signature 
' 

Public Class Certificate
    Protected sPath As String = ""
    Protected sPassword As String = ""

    Public akp As AsymmetricKeyParameter
    Public chain As X509Certificate()
    Public sLastError As String = ""


    ' 
    ' This method will load the given pkcs certificate in sFile
    ' 

    Public Function LoadCertificate(ByVal sPath As String, ByVal sPassword As String) As Boolean
        Dim sAlias As String = Nothing
        Dim pk12 As Pkcs12Store

        Try
            Me.sPath = sPath
            Me.sPassword = sPassword

            'Check if file exists
            If Not File.Exists(sPath) Then
                Me.sLastError = "The file " & sPath & " does not exist"
                Return False
            End If

            'Read the certificate file
            pk12 = New Pkcs12Store(New FileStream(sPath, FileMode.Open, FileAccess.Read), sPassword.ToCharArray())

            'Iterate throught the certificate entries to find the private key entry
            Dim i As IEnumerator = pk12.Aliases.GetEnumerator()
            While (i.MoveNext())
                sAlias = i.Current.ToString
                If pk12.IsKeyEntry(sAlias) Then Exit While
            End While

            Me.akp = pk12.GetKey(sAlias).Key
            Dim ce As X509CertificateEntry() = pk12.GetCertificateChain(sAlias)
            ReDim Me.chain(0 To ce.Length - 1)
            For k As Integer = 0 To ce.Length - 1
                chain(k) = ce(k).Certificate
            Next

            Return True
        Catch ex As Exception
            Me.sLastError = ex.Message
            Return False
        End Try
    End Function

End Class


Imports System.IO

Imports iTextSharp.text.xml.xmp

' 
' This class wraps the PDF metadata
' 

Public Class PdfMetaData
    Protected info As Hashtable = New Hashtable()

#Region "Properties"
    Public Property Author() As String
        Get
            Return info("Author")
        End Get
        Set(ByVal value As String)
            If info.ContainsKey("Author") Then
                info("Author") = value
            Else
                info.Add("Author", value)
            End If
        End Set
    End Property

    Public Property Title() As String
        Get
            Return info("Title")
        End Get
        Set(ByVal value As String)
            If info.ContainsKey("Title") Then
                info("Title") = value
            Else
                info.Add("Title", value)
            End If
        End Set
    End Property

    Public Property Subject() As String
        Get
            Return info("Subject")
        End Get
        Set(ByVal value As String)
            If info.ContainsKey("Subject") Then
                info("Subject") = value
            Else
                info.Add("Subject", value)
            End If
        End Set
    End Property

    Public Property Keywords() As String
        Get
            Return info("Keywords")
        End Get
        Set(ByVal value As String)
            If info.ContainsKey("Keywords") Then
                info("Keywords") = value
            Else
                info.Add("Keywords", value)
            End If
        End Set
    End Property

    Public Property Producer() As String
        Get
            Return info("Producer")
        End Get
        Set(ByVal value As String)
            If info.ContainsKey("Producer") Then
                info("Producer") = value
            Else
                info.Add("Producer", value)
            End If
        End Set
    End Property

    Public Property Creator() As String
        Get
            Return info("Creator")
        End Get
        Set(ByVal value As String)
            If info.ContainsKey("Creator") Then
                info("Creator") = value
            Else
                info.Add("Creator", value)
            End If
        End Set
    End Property

    Public ReadOnly Property MetaData() As Hashtable
        Get
            Return Me.info
        End Get
    End Property

#End Region

#Region "Initialization"
    Public Sub New()
        Me.Author = ""
        Me.Title = ""
        Me.Subject = ""
        Me.Keywords = ""
        Me.Producer = ""
        Me.Creator = ""
    End Sub
#End Region

#Region "Functions"
    ' 
    ' Retruns the PDF metadata as an array of bytes
    ' 

    Public Function GetMetaDataXmp() As Byte()
        Dim os As MemoryStream = New System.IO.MemoryStream()
        Dim xmp As XmpWriter = New XmpWriter(os, Me.info)
        xmp.Close()
        Return os.ToArray()
    End Function
#End Region

End Class

MS SQL Server: Generate SQL insert script from table data

2008-11-14T02:21:00.000-08:00

Unfortunately Microsoft SQL Server (including the management studio) does not provide a good way to generate a SQL insert script from the data in your tables. I don't know why they did not include this feature, like in MySQL, but it means we have to build it our selfs. Below you will find a stored procedure that will generate a complete insert script from the data in the table given as parameter.


CREATE PROCEDURE SP_GenerateInserts
    @TableName as varchar(40)
AS
BEGIN
    SET NOCOUNT ON;

    create table #tmp (
    SQLText varchar(8000) )

    create table #tmp2 (
    Id int identity,
    SQLText varchar(8000) )

    delete #tmp
    delete #tmp2

    declare @vsSQL varchar(8000),
    @vsCols varchar(8000),
    @vsTableName varchar(40)

    declare csrTables cursor for
    select name
    from sysobjects
    where type in ('u')
    and name = @TableName
    order by name

    open csrTables
    fetch next from csrTables into @vsTableName

    while (@@fetch_status = 0)
    begin

    select @vsSQL = '',
    @vsCols = ''
    select @vsSQL = @vsSQL +
    CASE when sc.type in (39,47,61,111) then
    '''''''''+' + 'isnull(rtrim(replace(['+ sc.name + '],'''''''','''''''''''')),'''')' + '+'''''',''+'
    when sc.type = 35 then
    '''''''''+' + 'isnull(rtrim(replace(substring(['+ sc.name + '],1,1000),'''''''','''''''''''')),'''')' + '+'''''',''+'
    else
    'isnull(convert(varchar,[' + sc.name + ']),''null'')+'',''+'
    end
    from syscolumns sc
    where sc.id = object_id(@vsTableName)
    order by ColID

    select @vsCols = @vsCols + quotename(sc.name,'[') + ','
    from syscolumns sc
    where sc.id = object_id(@vsTableName)
    order by ColID

    select @vsSQL = substring(@vsSQL,1,datalength(@vsSQL)-1)

    select @vsCols = substring(@vsCols,1,datalength(@vsCols)-1)

    insert #tmp
    exec ('select ' + @vsSQL + ' from ' + @vsTableName)

    update #tmp
    set sqltext = 'insert ' + @vsTableName + '(' + @vsCols + ') values(' + substring(sqltext,1,datalength(sqltext)-1) + ')'

    insert #tmp2
    select 'DELETE from ' + @vsTableName

    insert #tmp2 values ('GO')

    if (select count(id) from syscolumns where id = object_id(@vsTableName) and ((status & 128) = 128) ) = 1
    begin
    insert #tmp2
    select 'set identity_insert ' + @vsTableName + ' on'
    end

    insert #tmp2
    select * from #tmp

    if (select count(id) from syscolumns where id = object_id(@vsTableName) and ((status & 128) = 128) ) = 1
    begin
    insert #tmp2
    select 'set identity_insert ' + @vsTableName + ' off'
    end

    insert #tmp2 values ('GO')

    insert #tmp2
    select 'update statistics ' + @vsTableName

    insert #tmp2 values ('GO')

    delete #tmp

    fetch next from csrTables into @vsTableName

    end

    close csrTables
    deallocate csrTables

    update #tmp2
    set sqltext = substring(sqltext,1,charindex(',)',sqltext)-1) + ',NULL)'
    where not(charindex(',)',sqltext) = 0)

    update #tmp2
    set sqltext = replace(sqltext, ',''''',',null')
    where not (charindex(',''''',sqltext) = 0)

    update #tmp2
    set sqltext = replace(sqltext, '(''''',',null')
    where not (charindex('(''''',sqltext) = 0)

    select sqltext from #tmp2 order by id

    drop table #tmp
    drop table #tmp2

END
GO

Installing OpenOffice.org 3.0: Files in use by Explorer

2008-10-17T02:48:00.000-07:00

Today I installed OpenOffice 3.0. I encountered some problems while installing though. According to OpenOffice some files were in use by other programs. So I closed all other programs, just to be sure. Most setup programs would just ask for a reboot, so the files that are in use can be replaced at boot time, but not OpenOffice. Well, it doesn't seem to be a big problem to close all programs right? Unfortunatily, OpenOffice was still not satisfied when I closed all programs. Some of the file were in use by Explorer.exe, which is the main process of Windows Vista.

How to overcome this problem and install OpenOffice anyways:

Close all applications
Start the OpenOffice.org 3.0 setup program
Continue until it tells you that you need to close Explorer.exe
Open the task manager (control + shift + escape)
Go to the Processes tab in the task manager
Click the button or checkbox that says `Show processes from all users`
If Windows asks for administrator rights, grand it
Find the Image name ´explorer.exe´, click it, and after that click ´End Process´
Now the Windows menu/application bar will disappear
Switch back to the OpenOffice.org installer and click the try again button
Now OpenOffice will install without problems
After the installation is complete, you may want to get your menu/application bar back. You can do this by choosing File -> New Task in the task manager menu. Enter 'explorer' in the text field and press enter.

Vista boot disc / recovery disc

2008-09-29T01:09:00.000-07:00

When you need to start Windows Vista from a CD/DVD because the version on the harddisk does not work properly anymore, the question rises how to make a boot disc? I had this problem recently on a laptop where there where disc errors on the C partition. Normally you could just schedule a disc check, unfortunately this did not work (chkdisc did not start). The truth is that I couldn't find out how to make a boot disc, maybe it is not even possible...

I found a solution though, you can download a recovery disc from this website. With this disc I was able to boot from CD and run chkdisc from the CD. The size of the download is approximatly 120 MB and best of all completly free.