Ruby & Excel: Inserting Pictures Into Cells

A reader recently asked how to insert an image from their PC into a cell in an Excel worksheet. So if you have a couple of minutes, I'll demonstrate how to insert an image, specify the exact position, and resize the image.

Let's start by connecting to an open Excel worksheet:

require 'win32ole'
xl = WIN32OLE.connect('Excel.Application')
ws = xl.ActiveSheet

Inserting the Image

To insert a picture into a worksheet, call the Worksheet object's Pictures.Insert() method, passing it the filename of the image to insert:

pic = ws.Pictures.Insert('C:\Pictures\Image1.jpg')

The Pictures.Insert() method inserts a new Picture object into the Pictures collection and returns a reference to the new Picture object, which we've assigned to the variable pic.

Positioning the Image

OK, now that you've got the picture inserted into the worksheet, you probably want to specify its exact position, perhaps aligned with a certain range of cells. Let's start by defining that range of cells, from cell C3 to cell F5:

range = ws.Range('C3:F5')

We want the picture aligned with the top/left corner of our range, so we'll set our Picture object's Top and Left properties to be the same as our Range object's Top and Left properties.

pic.Top = range.Top
pic.Left = range.Left

Resizing the Image

Now that we have the top/left position set, let's move on to specifying the width and height of the picture. The original image has an aspect ratio, which is the image's width divided by its height. An image that is 800x600 pixels could be said to have an aspect ratio of 4:3. When resizing an image, you may wish to maintain its original aspect ratio, to avoid making the image appear stretched in one direction or the other.

By default, a Picture object in Excel has its aspect ratio locked, so that when you change either the width or the height, the other dimension is automatically adjusted to preserve the aspect ratio.

You adjust the width and/or height of a Picture object by setting its---wait for it---Width and Height properties. With the aspect ratio locked, we can set the image to fill the width of the range...

pic.Width = range.Width

...or to fill the height of the range...

pic.Height = range.Height

...but we cannot successfully apply both settings without first unlocking the aspect ratio.

To unlock the Picture's aspect ratio, you set the Picture object's ShapeRange.LockAspectRatio property to false:

pic.ShapeRange.LockAspectRatio = false

Now that we have unlocked the aspect ratio, we can set the picture's width and height to match the range's width and height:

pic.Width = range.Width
pic.Height = range.Height

The Width and Height properties are just numerical values. So you could instead do something like this:

pic.Width = 400
pic.Height = 300

And that, my friends, is how you insert, position, and resize an image in Excel.

Let me know if you have any questions or comments, and thanks for stopping by!

Ruby & Excel: Hiding and Unhiding Columns, Rows, and Worksheets

Occasionally, when working with Excel, you may have a need to hide certain columns or rows in a worksheet. As an example, perhaps your worksheet lists revenue for each of 12 months, but your intended recipient only wants to see the columns showing year-to-date totals. Whatever the reason, you'd like to simply hide certain columns (or rows) rather than delete them completely. And since you're here, you'd probably prefer to do that with Ruby code...

Let's set the scene by assuming that your code is working with an open workbook and you want to hide columns in the currently selected worksheet:

require 'win32ole'
xl = WIN32OLE.connect('Excel.Application')
wb = xl.ActiveWorkbook
ws = xl.ActiveSheet

Hiding Columns

To hide one or more columns, obtain a reference to the column range(s) and set the Hidden property to true:

ws.Columns('A').Hidden = true
ws.Columns('D:K').Hidden = true

Unhiding (displaying) columns works the same way; except, of course, you set the Hidden property to false:

ws.Columns('A').Hidden = false
ws.Columns('D:K').Hidden = false

The following code ensures that all columns in a worksheet are visible:

ws.Columns.Hidden = false

Hiding Rows

Rows have a Hidden property, too, so you can do this to hide rows...

ws.Rows('3').Hidden = true
ws.Rows('7:11').Hidden = true

...and to unhide them:

ws.Rows('3').Hidden = false
ws.Rows('7:11').Hidden = false

Hiding Worksheets

But what if you want to hide an entire worksheet? The Worksheet object doesn't have a Hidden property. Instead, you'll use the Visible property. So to hide the 'Great Amish Scientists' worksheet in the active workbook (wb), we'd use this code:

wb.Worksheets('Great Amish Scientists').Visible = false

And to unhide it, we'd toggle the Visible property back to true:

wb.Worksheets('Great Amish Scientists').Visible = true

The following code ensures that all worksheets in a workbook are visible:

wb.Worksheets.each do |ws|
    ws.Visible = true
end

And that, folks, is pretty much all there is to it. Let me know if you have any questions or comments, and thanks for stopping by!

wxRuby: Changing Text Fonts and Colours

A reader recently asked me how to change the text font size and color for wxRuby controls such as the StaticText control. Let's take a look at how you can do this.

Imagine, if you will, that we have a StaticText control named my_control...

Changing Fonts

We'll begin by creating a new Font object by calling the Font.new() method:

my_font = Wx::Font.new()

Next, we'll set various attributes of our new Font object:

my_font.set_point_size(20)
my_font.set_family(Wx::FONTFAMILY_MODERN)
my_font.set_style(Wx::FONTSTYLE_ITALIC) 
my_font.set_weight(Wx::FONTWEIGHT_BOLD)

Once we have our Font object defined to our satisfaction, we can then pass it to our control's set_font() method:

my_control.set_font(my_font)

Changing Colors

Text color is not an attribute of the Font object, but is rather the foreground color of the control. So, to change the color of the text, we call the control's set_foreground_colour() method and pass it a Colour object. We'll make it easy and use one of wxRuby's built-in Colour constants:

my_control.set_foreground_colour(Wx::RED)

Make a note of the spelling: colour, not color.

Further Reading

A simple working example can be found here.

Documentation of the Font object can be found here.

Documentation of the set_foreground_colour() method can be found here.

Documentation of the Colour object can be found here.

And there you have it. Let me know if you'd like to see more on this or other subjects.

Thanks for stopping by!

Ruby & Word: Inserting Tables

Microsoft Word is great for text documents. Microsoft Excel is great for tables of data. But, sometimes, you need to get your chocolate in your peanut butter. In other words, you may occasionally need to include a table in a Word document. Let's walk through how to do that.

Setting the Stage

To borrow an example from my upcoming book, let's say that you want to insert a table that contains a list of all movies starring Spencer Tracy and Katharine Hepburn, including the year each movie was released, the title, and the director. Your 2-dimensional films array might look like this:

films = []
films << ["1942", "Woman of the Year", "George Stevens"]
films << ["1942", "Keeper of the Flame", "George Cukor"]
films << ["1945", "Without Love", "Harold S. Bucquet"]
films << ["1947", "The Sea of Grass", "Elia Kazan"]
films << ["1948", "State of the Union", "Frank Capra"]
films << ["1949", "Adam's Rib", "George Cukor"]
films << ["1952", "Pat and Mike", "George Cukor"]
films << ["1957", "Desk Set", "Walter Lang"]
films << ["1967", "Guess Who's Coming to Dinner", "Stanley Kramer"]

Let's connect to a running instance of Word and use the currently selected document:

require 'win32ole'
word = WIN32OLE.connect('Word.Application')
doc = word.ActiveDocument

Moving to the End of the Document

First, let's move to the end of the document, where we'll add our new table. We do this by calling the Selection.EndKey() method, which moves the selection to the end of a word, line, or document. We'll pass this method a value of 6, which specifies that we want to move to the end of the document:

word.Selection.EndKey(6)

Adding a New Table

The Tables collection in Word's object model represents all the Table objects in a selection, range, or document. To add a new Table to a document, call the Document object's Tables.Add() method and pass it three parameters:

* The range object representing where the table is to be inserted
* The number of rows for the new table
* The number of columns for the new table

Now let's add a new table with one row and three columns (we'll add more rows later):

table = doc.Tables.Add(word.Selection.Range, 1, 3)

The Tables.Add() method returns a reference to the newly created table, which we have assigned to the cleverly named variable table.

Inserting Text into Table Cells

You can reference a single cell in a table by calling the Cell() method and passing it the row and column numbers (NOTE: the first row or column is represented by 1, not 0). Once you have your cell, you can set the text via its Range.Text property; so we add the header text as follows:

table.Cell(1, 1).Range.Text = 'Year'
table.Cell(1, 2).Range.Text = 'Film Title'
table.Cell(1, 3).Range.Text = 'Director'

Adding Rows

To add a row to your table, simply call the Table object's Rows.Add() method. Now that we've added the header text, let's iterate over our films array and add a new row to the table for each film and insert the text:

films.each_with_index do |film, r|
    table.Rows.Add()
    film.each_with_index do |field, c|
        table.Cell(r + 2, c + 1).Range.Text = field
    end
end

There you have it. Thanks for stopping by!

Ruby & Word: Counting Words and Pages

Someone recently asked how to get a count of the number of words and pages in a Microsoft Word document. This is done by calling the ComputeStatistics() method on a Range or Document object.

As an example (play along at home), let's imagine that you have a Word document open. Your first step is to use the win32ole library's connect() method to connect to the existing instance of Word:

require 'win32ole'
word = WIN32OLE.connect('Word.Application')

You pass the ComputeStatistics() method an integer representing the type of statistic that you want to calculate. In other words, "What do you want to count?" So let's take a moment to define constants for those values:

WdStatisticCharacters = 3
WdStatisticCharactersWithSpaces = 5
WdStatisticWords = 0
WdStatisticLines = 1
WdStatisticParagraphs = 4
WdStatisticPages = 2

You can call the ComputeStatistics() method on a Document object...

doc = word.ActiveDocument
word_count = doc.ComputeStatistics(WdStatisticWords)
page_count = doc.ComputeStatistics(WdStatisticPages)

...or on a Range object...

paragraph = doc.Paragraphs(27)
word_count = paragraph.Range.ComputeStatistics(WdStatisticWords)
char_count = paragraph.Range.ComputeStatistics(WdStatisticCharacters)

When called on a Document object, the method accepts an optional second parameter, IncludeFootnotesAndEndnotes, a boolean which (obviously) specifies if the calculation should include footnotes and endnotes:

word_count = doc.ComputeStatistics(WdStatisticWords, true)

The IncludeFootnotesAndEndnotes parameter defaults to false.

Official details on the ComputeStatistics() method are available from MSDN here.

That's all for now. Thanks for stopping by!

Ruby & Word: Creating and Applying Styles

Microsoft Word uses the Styles model to apply a set of pre-defined formatting to text. Styles can also serve a second purpose, to tag sections of the document as normal, title, headings and such. You can then, for example, create a Table of Contents in Word based on the text that is formatted with the Heading styles.

Naturally, you can do all this with code (otherwise, I wouldn't be wasting your time here). Over the next few minutes, we'll walk through the process of creating a new Style, setting its properties, and then applying that style to text.

The Style object represents a single built-in or user-defined Word style. The Styles collection contains all the Style objects within a document. To reference the Styles collection, simply call the Styles method on the document:

doc = word.ActiveDocument
styles = doc.Styles

To create a new Style, we call the Add() method on the Styles object and pass it a hash defining the name and the type of the new Style. The following code creates a new Paragraph style named 'Code':

code_style = doc.Styles.Add({'Name' => 'Code', 'Type' => 1})

The Type property defines what StyleType your new Style is based on. Possible values are:

WdStyleTypeParagraph = 1
wdStyleTypeCharacter = 2
WdStyleTypeTable     = 3
WdStyleTypeList      = 4

The default is WdStyleTypeParagraph.

The Add() method returns a reference to the newly-created Style object. Now that you have your new Style object, you can customize it through various properties that you can set. As a starting point, you may want to base your new style on another style by setting the BaseStyle property:

code_style.BaseStyle = 'Normal'

Font properties can be defined...

code_style.Font.Name = 'Consolas'
code_style.Font.Size = 12
code_style.Font.Bold = false

...as well as paragraph spacing and background colors:

code_style.NoSpaceBetweenParagraphsOfSameStyle = true
code_style.Shading.BackgroundPatternColor = 15132390

Note that not all properties will apply to all style types.

Now that you've created your own Style, you might want to automatically apply it to some existing text. The following code iterates over each paragraph in the document (doc variable). For each paragraph that uses the 'Preformatted Text' style, the new 'Code' style is applied instead:

doc.Paragraphs.each do |paragraph|
    if paragraph.Style.NameLocal == 'Preformatted Text'
        paragraph.Style = 'Code'
    end
end

There you have it. If you'd like to learn more here about Styles, or anything else related to automating Word with Ruby, please let me know.

Thanks for stopping by!

The OCRA Compiler: Tips, Tricks, and Gotchas

I've previously mentioned Lars Christensen's One-Click Ruby Application Builder, a "compiler" for Ruby scripts that shows a lot of potential (and current value). There's not much documentation yet, but folks are installing it, using it, and providing feedback. It works right out of the box for many purposes, but here are a few things to keep in mind as you use it...

"Failed to create directory" Error

One user reported receiving the error "Failed to create directory" when running the compiled executable. As a possible workaround, try running ocra.rb from the directory where your script is located. For example, instead of running...

ocra.rb "C:\code\rubyscripts\application.rbw"

...navigate to the "C:\code\rubyscripts" directory, then run:

ocra.rb application.rbw

Note that while this resolved the problem on my machine, it didn't help the person who originally reported the problem.

Require RubyGems

When you compile your script (which uses one or more gems) with OCRA and then run the executable, you may receive a 'no such file to load' error. Try adding the line...

require 'rubygems'

...to the top of your script, above the other require statements. I've found that a script that runs pre-compiled without this statement may not execute once compiled.

Compile Without Running

I mentioned earlier that it would be nice to have an option to avoid fully running the script, similar to RubyScript2Exe's exit if RUBYSCRIPT2EXE.is_compiling? idiom. A tip of the hat goes to reader "BackOrder", who offered the following solution:

exit if Object.const_defined?(:Ocra)

Put all your require statements at the top of your code, followed by this line.

OCRA and Mechanize: "libxml2.dll not found"

There may be a problem compiling a script that requires the mechanize gem. Running the compiled executable resulted in a "libxml2.dll was not found" error on my machine.

Note that the above observations relate to version 1.0.2 (current as of this writing) of the ocra gem.

More information is available in the OCRA forums and bug tracker.

Thanks again to Lars for creating OCRA, and to the users who have installed it, used it, and provided their feedback.

Thanks for stopping by!