Home > Articles > Programming

Writing Business Logic with the Apex Programming Language for the Force.com Platform

  • Dec 27, 2013
This chapter introduces Apex, a programming language designed for the Force.com platform, as a language for writing business logic, specifically where it interacts with the Force.com database.
This chapter is from the book

This chapter is from the book

Development with the Force.com Platform: Building Business Applications in the Cloud, 3rd EditionDevelopment with the Force.com Platform: Building Business Applications in the Cloud, 3rd Edition

Learn More Buy

This chapter is from the book

This chapter is from the book

Development with the Force.com Platform: Building Business Applications in the Cloud, 3rd EditionDevelopment with the Force.com Platform: Building Business Applications in the Cloud, 3rd Edition

Learn More Buy

Business logic in Force.com is developed in Apex, a programming language designed for the Force.com platform. Through Apex code, many platform features, such as the database and user interface, can be customized to meet the needs of individual users and companies.

This chapter introduces Apex as a language for writing business logic, specifically where it interacts with the Force.com database. It uses a combination of explanatory text and code snippets to introduce concepts and encourage experimentation. This approach assumes you’re already experienced in some other high-level, object-oriented programming language and would like to see for yourself how Apex is different.

The chapter consists of the following sections:

  • Introduction to Apex—Learn basic facts about Apex and how it differs from other programming languages.
  • Introducing the Force.com IDE—Take a brief tour of the Force.com IDE, a user interface for developing, debugging, and testing Apex code.
  • Apex language basics—Learn the building blocks of the Apex language, such as data types and loops.
  • Database integration in Apex—Incorporate the Force.com database into your Apex programs through queries, statements that modify data, and code executed automatically when data is changed.
  • Debugging Apex using Developer Console—With Developer Console, you can directly inspect the state of your Apex code as it runs.
  • Unit tests in Apex—Write tests for your code and run them in Developer Console.
  • Sample application—Walk through the implementation of a data validation rule for the Services Manager sample application.

NOTE

The code listings in this chapter are available in a GitHub Gist at http://goo.gl/evtet.

Introduction to Apex

Apex is a stored procedure-like language that runs entirely on the Force.com platform. It provides object-oriented features and tight integration with the Force.com database. It’s mainly used in custom user interfaces and in triggers, code that is executed when data is changed in the database.

Apex is not a general-purpose programming language like Java or C. Its scope is limited to business and consumer applications that operate on relational data and can benefit from the feature set of the surrounding Force.com platform.

Apex programs exist in a multitenant environment. The computing infrastructure used to execute Apex is operated by Salesforce and shared among many developers or tenants of the system. As a result, unlike general-purpose programming languages you are familiar with, the execution of Apex programs is closely controlled to maintain a consistently high quality of service for all tenants.

This control is accomplished through governor limits, rules that Force.com places on programs to keep them operating within their allotted share of system resources. Governor limits are placed on database operations, memory and bandwidth usage, and lines of code executed. Some governor limits vary based on the type of licensing agreement you have in place with Salesforce or the context that the code is running in, and others are fixed for all users and use cases.

NOTE

The most prevalent governor limits are discussed throughout this book, but it is not a complete treatment of the subject. The authoritative guide to governor limits is the Force.com Apex Code Developer’s Guide, available at http://developer.force.com. Educate yourself on governor limits early in the development process. This education will alter the way you architect your Apex code and prevent costly surprises. Additionally, test all of your Apex code with production-like data volumes. This helps to expose governor-related issues prior to a production deployment.

Here are a few important facts about Apex:

  • It includes integrated testing features. Code coverage is monitored and must reach 75% or greater to be deployed into a production environment.
  • It is automatically upgraded. Salesforce executes all of its customers’ unit tests to verify that they pass before deploying a major release of the Force.com platform. Your code is always running on the latest version of Force.com and can take advantage of any and all new functionality without the hassle and risks of a traditional software upgrade process.
  • There is no offline runtime environment for Force.com. You can edit your code on your desktop computer, but it must be sent to Force.com for execution.
  • Apex is the only language that runs on the Force.com platform. You can integrate Apex with programs running outside of Force.com using HTTP-based techniques such as REST.
  • The Force.com database is the only database integrated into the Apex language. Other databases can be integrated through Web services or other technology using HTTP.

The two primary choices for developing Apex code are the Web-based App Builder Tools and the Force.com IDE, provided as a stand-alone application as well as a plug-in to the standard Eclipse IDE. The Force.com IDE is the more powerful and developer-friendly of the two, so it is used throughout this book.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020