Contents

 Aliases represents a powerful tool to refer custom fields indirectly making your scripts function obvious. 

The Case For Aliases

Addressing fields by its Jira internal name is not useful. Nobody likes to write 'customfield_12067' instead of a meaningful variable name. Thus we allowed to address the fields by name though with the disadvantage that certain errors may appear: field name resolution does not take into account that there may be more than one custom field with that name.

Look into the following code:

if(isNotNull(customfield_10001) // or #{The Reported User)} if accessed by name
{
  assignee=customfield_10001; // assign the report to him or her
}

This code is meaningless without comments as the whole script purpose evades from the programmer's eye. A better option is following:

if(isNotNull(#{Reported User}) // or customfield_10001 if accessed by number
{
  assignee=#{Reported User}; // assign the report to him or her
}

Such coding style has the disadvantage that there may be more than one custom field with Reported User name. SIL takes into account the first custom field resolved by name in such case. Therefore, SIL has created its own custom field naming system, one that is independent of the IDs attributed by Jira to custom fields and one which can provide the much better distinction of the custom fields names. The feature is called SIL aliases, and allows you to alias any custom field with a friendly name. Let's see how this simple example looks with aliases.

Aliases

Creating aliases is a simple task of editing a properties file named 'sil.aliases', which is placed in Kepler Home directory. This file must contain pairs in the form alias=customfield_id. For our example above, we should edit it and put an entry like:

# custom fields aliases
reportedUser=customfield_10001

The script may be re-written in another way, instead of the custom field ID or name the alias is used:

if(isNotNull(reportedUser)) {
  assignee=reportedUser;
}

Now the code looks clean and the script function creator is clear even without comments.

Summary

Using SIL aliases instead of custom fields IDs and names is supreme. There are important results when maintaining a complex Jira install:

1. When and if a custom field gets deleted and recreated, its ID changes. Using SIL aliases allows you to keep your code unchanged, you just need to point in the sil.aliases file the new custom field ID for that alias.
2. May simplify the syntax and may clarify the meaning of the scripts.
3. Aliases provide independence of the Jira instance.

Since 1 and 2 are obvious, let's discuss the 3rd point: the independence of the Jira instance.  Think of two Jira systems, for instance test environment and production environment. You do not want to work directly into production so normally you develop your new workflow on the test environment and you add a new custom field. Now, everything is ready and you want to publish changes into production system, so:

• You create on the production system a custom field with the same name. But Jira assigns its own ID, which may be different from the ID on the test system
• You move over the SIL scripts
• You import the workflow, with the paths changed to the above SIl scripts if necessary

Now, if you referred your custom field by its ID, you need to go through every script and do a search and replace with the new ID. If you referred it by name, maybe your colleague just added a custom field, used in some other project, that has the same name.

However, if you used the alias, you just place your alias in that file, and everybody is happy.

Another Example

If you're still not convinced, let's take a look at another example. Look into this post function:

 if(customfield_10000 < currentDate() && customfield_10001 > currentDate()) {
	assignee = customfield_10002;
 }

From the code above, it is quite clear that customfield_10000 and customfield_10001 are dates; customfield_10002 is a user picker. But their meaning is unknown. However, if we define the following aliases:

 initialDate=customfield_10000
 finalDate=customfield_10001
 contact=customfield_10002

Then we use them in our SIL program.

 if(initialDate < currentDate() && finalDate > currentDate()) {
 	assignee = contact;
 }

Something starts to make sense, don't you think?