Developing Apama Applications > EPL Naming Conventions
EPL Naming Conventions
It is recommended that you use the following naming conventions in EPL. These conventions closely follow Java naming conventions. Using these conventions makes it easier to collaborate and makes it faster for Software AG Global Support personnel to follow your code.
Item
Convention
Notes and Examples
Acronyms
Do not always use all capitals
Names often contain standard abbreviations, such as IAF for Integration Adapter Framework. Names such as iafInterface for an attribute or IafInterface for a monitor are easier to read than iAFInterface and IAFInterface.
Actions
lowerCamelCase
Actions should be verbs, in mixed case with the first letter lowercase, and the first letter of each internal word capitalized. For example:
handleQuery();
startDaemonProcess();
quit();
Channels
package. UpperCamelCase
Channel names should start with an EPL package name (lowercase), optionally followed by an UpperCamelCase noun. Qualifying channel names with a package is important because channel names form a global namespace that is shared by all applications running in a correlator. For example:
com.mycompany.AllTransactions
Constants
ALL_CAPITALS
Identifiers for constants should be all uppercase with words separated by underscores. For example:
constant integer MAX_SIZE;
constant string DEFAULT_HOST;
Contexts
UpperCamelCase
Context names should be nouns, initial capital, in mixed case with the first letter of each internal word capitalized. Context names should be simple and should describe the work being done in the context. Use whole words. Avoid acronyms and abbreviations unless the abbreviation is much more widely used than the long form, such as URL or IAF. For example:
context(“Calculation”);
context("Inventory", true);
Custom aggregate functions
lowerCamelCase
Custom aggregate functions should be in mixed case with the first letter lowercase, and the first letter of each internal word capitalized.
aggregate bounded myCustomAggregate() returns integer { aggregateBody }
Events
UpperCamelCase
Event names should have an initial capital, and mixed case with the first letter of each internal word capitalized. Event names should be simple and descriptive. Use whole words. Avoid acronyms and abbreviations unless the abbreviation is much more widely used than the long form, such as URL or IAF. For example:
event Tick
event SubscriptionConfiguration
event IafEvent
Monitors
UpperCamelCase
Monitor names should be nouns, initial capital, in mixed case with the first letter of each internal word capitalized. Monitor names should be simple and descriptive. Use whole words. Avoid acronyms and abbreviations unless the abbreviation is much more widely used than the long form, such as URL or IAF. For example:
monitor SubscriptionManager
monitor IafMonitorService
Packages
lowercase
The prefix of a unique package name is always written in all-lowercase ASCII letters and should preferably be one of the top-level domain names — com, edu, gov, mil, net, org, or one of the two-letter codes identifying countries as specified in ISO 3166-1 alpha-2.
Subsequent components of the package name vary according to an organization's own internal naming conventions. Such conventions might specify that certain directory name components be division, department, project, machine, or login names. For example:
com.apamax.accounting
Queries
UpperCamelCase
Query names should be nouns, initial capital, in mixed case with the first letter of each internal word capitalized. Query names should be descriptive. Use whole words. Avoid acronyms and abbreviations unless the abbreviation is much more widely used than the long form, such as URL or IAF. For example:
query FaultyWithdrawalLocations
query CloseInTimeButDistantTransactions
Variables
lowerCamelCase
Variables and parameters should have initial lowercase. This is left to your discretion, but lowercase is preferable. Internal words start with capital letters.
Variable names should be short yet meaningful. The choice of a variable name should be mnemonic: that is, designed to indicate to the casual observer the intent of its use. One-character variable names should be avoided except for temporary, throwaway, variables. Common names for temporary variables are i, j, k, m, and n for integers.
integer i;
float myPrice;
MyEvent myEvent;
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