Apex Collection Library

Library allowing collection manipulations in APEX which helps in reducing conditional for loops.
The main goal is to provide all the functionality in a standalone class without much preformance overhead.

Latest version: 0.0.4

Features

• fluent interface within standalone class
• operations chaining
• lazy evaluation
• missing fields detection (not populated, not existing)

Example Usage

Filtering

Filter accounts whose Name field equals Foo

List<Account> filteredAccounts = Collection.of(accountList)
	.filter()
	.byField(Account.Name).eq('Foo')
	.get();

Filter accounts whose Name field equals Foo and field AnnualRevenue is greater or equal than 150000

List<Account> filteredAccounts = Collection.of(accountList)
	.filter()
	.byField(Account.Name).eq('Foo')
	.andAlso()
	.byField(Account.AnnualRevenue).gte(150000)
	.get();

Get first account which Name field equals Bar or Foo

List<Account> filteredAccounts = Collection.of(accountList)
	.filter()
	.byField(Account.Name).eq('Bar')
	.orElse()
	.byField(Account.Name).eq('Foo')
	.getFirst();

Get top 10 accounts which AnnualRevenue field is less or equal than 100000

List<Account> filteredAccounts = Collection.of(accountList)
	.filter()
	.byField(Account.Name).lte(100000)
	.get(10);

Ignore non populated Website field (effectively treating them as null)

List<Account> filteredAccounts = Collection.of(accountList)
	.filter()
	.ignoreNonPopulatedFields()
	.byField(Account.Website).isNull()
	.get();

Grouping

Group accounts by Active__c Boolean field

Map<Object, List<Account>> groupedAccounts = Collection.of(accountList)
	.group()
	.byField(Account.Active__c)
	.get();

Reducing

Sum accounts AnnualRevenue field values

Decimal sum = Collection.of(accountList)
	.reduce()
	.byField(Account.AnnualRevenue)
	.sum();

Average accounts AnnualRevenue field values

Decimal sum = Collection.of(accountList)
	.reduce()
	.byField(Account.AnnualRevenue)
	.average();

Operations chaining

Filter accounts whose Name field equals to Foo then sum matching records AnnualRevenue field

Decimal sum = Collection.of(accountList)
	.filter()
	.byField(Account.Name).eq('Foo')
	.then()
	.reduce()
	.byField(Account.AnnualRevenue)
	.sum();

Filter accounts whose AnnualRevenue field is greater or equal than 100000 then group matching records by BillingCity field

Map<Object, List<Account>> found = Collection.of(accountList)
	.filter()
	.byField(Account.AnnualRevenue).gte(100000)
	.then()
	.group()
	.byField(Account.BillingCity)
	.get();

Considerations

Set and Map does not implement Iterable interface

Currently Set and Map types are not supported for manipulations, only List type

Changelog

v0.0.4

• Introduced breaking changes
• Renamed map operation to reduce
• Operation chaining proceeds by then() call
• Changed isIn and isNotIn filtering operations to accept only List<Object> values
• Improved class test coverage to 91.48%

v0.0.3

• Added operations chaining: filter-then-map, filter-then-group

v0.0.2

• Added mapping by field operations: sum, average
• Code base refactor

v0.0.1

• Initial version
• Added grouping by field operation
• Added filtering by fields operation