This document contains the Code snippet taken from the Commit notification.
Most of tricks on Groovy are taken from the code committed by Scott Gray , Joe Eckard , Marco Risaliti and others.
Groovy Features
Important thing to note down here is that we can use the Beanshell files as it is in Groovy but we should go with Goodies provided with Groovy Programing language.Here I am including few code snippet that is taken from Beanshell files and its equivalent Groovy code snippet to better understand the code.
Update note (2018-01-30): actually Beanshell has now been completely removed from OFBiz but this is still interesting to compare Java (Beanshell is same) and Groovy syntaxes.
Groovy Goodies
- Start the name of groovy file from capital letter and then follow the camel case pattern.For example "PendingCommunications.groovy".
The reason behind is shown below (Comments from Joe on Developer Mailing List) :- The main reason for this is that when a script is run without a class declaration, the filename is used to create the class name and you can experience problems with untyped variables. For example, a script named product.groovybecomes class "product", and if the script contains an untyped variable "product", it assumes you're trying to access the class "product" instead of a new variable "product".
- A secondary reason would be consistency, as some scripts have already been named this way. (EditProductFeatures.groovy, etc.
- Primary Key Definition
Beanshell :
productAssoc = delegator.findByPrimaryKey("ProductAssoc", UtilMisc.toMap("productId", productId, "productIdTo", productIdTo, "productAssocTypeId", productAssocTypeId, "fromDate", fromDate));
Groovy :
Pre EntityQuery : productAssoc = delegator.findByPrimaryKey("ProductAssoc", ['productId' : productId, 'productIdTo' : productIdTo, 'productAssocTypeId' : productAssocTypeId, 'fromDate' : fromDate]);
Post EntityQuery : productAssoc = from("ProductAssoc").where("productId", productId, "productIdTo", productIdTo, "productAssocTypeId", productAssocTypeId, "fromDate", fromDate).queryOne()
- Null check
Beanshell :
if (payment == null) continue;
Groovy :
if (!payment) continue; - Null + Size greater then Zero Check
Beanshell :
if (glAccounts != null && glAccounts.size() > 0) {
Groovy :
if (glAccounts) { - One line assignment
Beanshell :
nowDate = UtilDateTime.nowDate();
context.put("nowDate", nowDate);
Groovy :
context.nowDate = UtilDateTime.nowDate();
Note : Sentence can be kept in single line with the usage of DOT (.) for putting some values in context. - Beanshell :
String nowTimestampString = UtilDateTime.nowTimestamp().toString();
Groovy :
context.nowTimestampString = UtilDateTime.nowTimestamp().toString();
Note : No need to specify the object type. - No need to specify semicolon
Beanshell :
import org.ofbiz.product.inventory.InventoryWorker;
Groovy :
import org.ofbiz.product.inventory.InventoryWorker
Note : We can remove the semicolon in groovy import syntax. Always import the files that are being used in Groovy files instead of importing all the files from the package. - Beanshell :
List allTypes = new LinkedList();
i = invoiceItemTypes.iterator();
while ( i ) {
GenericValue invoiceItemType = i.next();
Groovy :
invoiceItemTypes.each {
GenericValue invoiceItemType = it;
or
invoiceItemTypes.each { invoiceItemType -> - Beanshell :
invoiceAppls = delegator.findByAnd("PaymentApplication", UtilMisc.toMap("invoiceId", invoiceId, "invoiceItemSeqId", null));
Groovy :
Pre EntityQuery : invoiceAppls = delegator.findByAnd("PaymentApplication", [invoiceId : invoiceId, invoiceItemSeqId : null]);
Post EntityQuery : invoiceAppls = invoice.getRelated("PaymentApplication", [invoiceItemSeqId : null], null, false)
Empty Map example
Beanshell :
product = new HashMap(); // Empty map
Groovy :
product = [:] ; Empty List example
Beanshell :
products = new ArrayList(); // Empty list
Groovy :
products = [] ;Important Note
This is pretty cool, groovy coerces objects into booleans:
An empty string,list,map = false otherwise true
An iterator with no more elements = false otherwise true
null = false- Beanshell :
while (iter.hasNext()) {
Groovy :
while (iter) {
Note : Another alternate of while statement is the usage of "each" on the list values. - List example
Beanshell :
if (UtilValidate.isNotEmpty(invoiceItemTypeOrgs)) {
Groovy :
if (invoiceItemTypeOrgs) {
Note : Not empty list returns true. - Map Example.
Beanshell :
if (UtilValidate.isNotEmpty(invoiceItemTypeOrgs)) {
Groovy :
if (invoiceItemTypeOrgs) {
Note : Not empty Map returns true. - String Example
Beanshell :
if (paymentId != null) {
Groovy :
if (paymentId) {
Note : Not empty String returns true. - Beanshell :
invoiceId = parameters.get("invoiceId");
Groovy :
invoiceId = parameters.invoiceId;
Note : The value coming from parameters map should be considered as String.Other types should be explicitly specified. - Elvis Operator : If any string return empty or null value then we can put Default value with the help of Elvis Operator ( ?: ) .Its short form of Java Ternary Operator.
Beanshell :
invoiceType = parameters.get("invoiceTypeId");
if (invoiceType == null) invoiceType = "ANY";
Groovy :
invoiceType = parameters.invoiceTypeId ?: "ANY" ; - Some important files that are responsible for Groovy handling in OFBiz.
a) GroovyUtil.java
b) GroovyServiceTest.groovy
c) GroovyEngine.java
d) ModelFormAction.java