How Creating A Presentation With Go Looks Like!

Download and Install Go

It goes without saying that you need to have Go installed on your computer.

Just for completeness, visit the Go project’s downloads page and select the binary distribution that matches your operating system and processor architecture.

The Go binary distributions assume they will be installed in /usr/local/go (or c:\Go under Windows), but it is possible to install them in a different location. If you do this, you will need to set the GOROOT environment variable to that directory when using the Go tools.

For example, if you installed Go to your home directory you should add the following commands to $HOME/.profile:

export GOROOT=$HOME/go
export PATH=$PATH:$GOROOT/bin

Under Windows, you may set environment variables through the “Environment Variables” button on the “Advanced” tab of the “System” control panel. Some versions of Windows provide this control panel through the “Advanced System Settings” option inside the “System” control panel. Edit the PATH-variable as follows: C:\go\bin; ...rest of PATH...

Go Code Organization

The go tool requires you to organize your code in a specific way.

Workspaces

Go code must be kept inside a workspace. A workspace is a directory hierarchy with three directories at its root:

• src contains Go source files organized into packages (one package per directory),
• pkg contains package objects, and
• bin contains executable commands.

The go tool builds source packages and installs the resulting binaries to the pkg and bin directories.

The src subdirectory typically contains version control repositories (such as for Git) that track the development of one or more source packages.

The GOPATH environment variable

The GOPATH environment variable specifies the location of your workspace.

To get started, create a workspace directory and set GOPATH accordingly. Your workspace can be located wherever you like. Note that this must not be the same path as your Go installation.

On my Windows computer, I have set GOPATH=C:\go_projects\go. Next I update my system environment variable PATH to include my workspace bin subdirectory i.e. PATH=%PATH%;%GOPATH%\bin;

Here’s my folder structure:

C:go_projects
+---go
+---bin
+---pkg
+---src

Package paths

The packages from the standard library are given short paths such as fmt and net/http. For your own packages, you must choose a base path that is unlikely to collide with future additions to the standard library or other external libraries. If you have a GitHub account at github.com/user, that should be your base path. We will use
github.com/user as our base path. Create a directory inside your workspace in which to keep source code. I have created the folder C:\go_projects\go\src\github.com\SatishTalim.

Tip: Replace SatishTalim with your own username.

Download and use package present

We shall use the Go package present to create our presentation. First, we need to use the go get command to download and install the package and its dependencies.

$ go get code.google.com/p/go.tools/cmd/present

On Windows the present.exe file is created in the folder GOPATH\bin.

Thanks to Dave Cheney for resolving an issue I had with the above command.

Write your .slide file

We need to write our .slide file as per the format specified here.

Here’s a file sample.slide in the folder C:\go_projects\go\src\github.com\SatishTalim\slides :

Sample Presentation
10 Mar 2014
Tags: go golang

Satish Talim
Go Hobbyist
satish@joshsoftware.com
http://satishtalim.com/
@IndianGuru

* Who is this guy?

.image ./talim.jpg

- Programming addict
- C, Java, Ruby, Go
- Director, JoshSoftware
.link http://www.joshsoftware.com/team The JoshSoftware team

* Example Go code

.play hello.go

The files talim.jpg and hello.go are also in the same folder namely C:\go_projects\go\src\github.com\SatishTalim\slides

You can download these 3 files from here.

Run present.exe

In the folder C:\go_projects\go\src\github.com\SatishTalim\slides type:

$ present
2014/03/10 04:22:37 Open your web browser and visit http://127.0.0.1:3999/

In your browser type http://127.0.0.1:3999/ and you should see:

Click on sample.slide and you should be able to see the presentation.

Also, go-talks.appspot plays slide presentations stored on GitHub in the present format. The syntax for GitHub URLs is:

http://go-talks.appspot.com/github.com/owner/project/file.ext

Thanks to Miki Tebeka for pointing this out.

The sample.slide that we have created can be seen online here.

That’s it! Have fun!