Trapdoor In The Sun

Alan Shanahan, Technician & Consultant


8 Comments

Force.com: Apex Styleguide, Part 1

Style, in any artistic or professional endeavour, is impossible to quantify, define or measure. It’s highly subjective and can often be controversial. So I’m going to push my own opinions in this, the first of several posts on the subject of coding styles. They won’t be complex articles, merely a look at what I think is poorly-written code versus how I believe it would be better presented. There will be no attempt to discuss whether the code in question is inherently “correct”; merely that it looks difficult to read and is hard to maintain. The aim is to turn both of these problems around, thus making the code easy to read and maintain.

In cases where there may be several variants, I will present them, and give a synopsis of how “stylish” I think it is.

Your comments, as always, are very welcome on this topic.

Example 1, SOQL Queries in Apex:

Let’s start with a common code segment whereby a SOQL Query is run and the resultant record set is returned into a list data structure.

List<Custom_Object__c> lstRecords = [select id, field1__c, name, number_field__c from custom_object__c where name like 'Smith%' order by lastname, firstname limit 100];

Figure 1, above, shows how an “undisciplined” programmer might put together a code segment that retrieves a record set from a SOQL query. In an IDE or other editor, this might well appear as a single line and you would have to scroll right to see the full detail.

List<Custom_Object__c> lstRecords = [select id, field1__c, name, number_field__c, an_additional_field__c, and_another__c from custom_object__c where name like 'Smith%' order by lastname, firstname limit 100];

Figure 2, above, would show the result of adding two additional fields to be retrieved by the query. Not very pretty.

List<Custom_Object__c> lstRecords = [
  SELECT
      Id
    , Field1__c
    , Name
    , Number_Field__c
  FROM Custom_Object__c
  WHERE Name LIKE 'Smith%'
  ORDER BY FirstName, LastName
  LIMIT 100
];

Figure 3, above, is how I would put this snippet together. I find this more professional-looking, much easier to read and far easier to modify. The following improvements have been made:

  • the outer data structure is separated from the inner SOQL statement
  • code is indented in a useful way
  • keywords are uppercase for readability
  • query clauses are split onto separate lines
  • fields are also split onto distinct lines and vertically-aligned to enable simple editing
  • field names have been retyped with appropriate letters in uppercase

You may not agree with the word “improvement”; please let me know if you don’t, and the all-important reason why.

List<Custom_Object__c> lstRecords = [
  SELECT
      Id
    , Field1__c
    , Name
    , Number_Field__c
    , An_Additional_Field__c
    , And_Another__c
  FROM Custom_Object__c
  WHERE Name LIKE 'Smith%'
  ORDER BY FirstName, LastName
  LIMIT 100
];

Figure 4, above, shows the result of adding the same two additional fields as in Figure 2. The results speak for themselves.

More code examples to follow soon. Why not follow the blog to get email notification of new posts?

Acronyms used above:
SOQL = Salesforce Object Query Language (a proprietary variant of SQL)
IDE = Integrated Development Environment (e.g. Eclipse, MS Visual Studio, NetBeans, JDeveloper, Xcode, etc.)

Advertisements