I wanted to set a value to a field in domain class.
For example,
class Example {
String name
String lastName
}
Now, from response I'm getting domain name, object instance id, field name and value. I have to set the value to the field in domain class.
Here I got the values as
domainName = 'Example'
instanceId = 1
fieldName = 'name'
valueToSet = 'XYZ'
So how should I set value to the field name? May be this is simple but I'm a new with grails and groovy.
Based on the domain name, a new domain instance has to be created at runtime. For this to happen, grailsApplication has to be injected. Here is a sample which can be modeled after in Controller or a Service class:
class SomeService {
def grailsApplication
def someMethod(String domainName, long instanceId,
String fieldName, def valueToSet) {
Class domainClazz = grailsApplication.domainClasses.find {
it.clazz.simpleName == domainName
}.clazz
def domainInstance = domainClazz.get( instanceId )
domainInstance."$fieldName" = valueToSet
domainInstance.save()
}
}
You can populate a Grails domain class by assigning a map to its properties, for example from the params in the controller (using that handy automatic binding). E.g.:
ded example=new Example()
example.properties=params
So you can see from this that the domain object can be treated as a set of properties. Which means you can use strings for keys, so you might have something like:
example['name']='XYZ'
I don't know whether that's what you're asking but I hope it helps.
Related
I am wondering if I can pass variable to be evaluated as String inside gstring evaluation.
simplest example will be some thing like
def var ='person.lName'
def value = "${var}"
println(value)
I am looking to get output the value of lastName in the person instance. As a last resort I can use reflection, but wondering there should be some thing simpler in groovy, that I am not aware of.
Can you try:
def var = Eval.me( 'new Date()' )
In place of the first line in your example.
The Eval class is documented here
edit
I am guessing (from your updated question) that you have a person variable, and then people are passing in a String like person.lName , and you want to return the lName property of that class?
Can you try something like this using GroovyShell?
// Assuming we have a Person class
class Person {
String fName
String lName
}
// And a variable 'person' stored in the binding of the script
person = new Person( fName:'tim', lName:'yates' )
// And given a command string to execute
def commandString = 'person.lName'
GroovyShell shell = new GroovyShell( binding )
def result = shell.evaluate( commandString )
Or this, using direct string parsing and property access
// Assuming we have a Person class
class Person {
String fName
String lName
}
// And a variable 'person' stored in the binding of the script
person = new Person( fName:'tim', lName:'yates' )
// And given a command string to execute
def commandString = 'person.lName'
// Split the command string into a list based on '.', and inject starting with null
def result = commandString.split( /\./ ).inject( null ) { curr, prop ->
// if curr is null, then return the property from the binding
// Otherwise try to get the given property from the curr object
curr?."$prop" ?: binding[ prop ]
}
i'm making a tables cleaning service that takes the table name and the date field as arguments , here is the service code :
def cleanTables(tableName , dateField) {
def comparisonDate
def numOfRecordsDeleted
use (TimeCategory){
comparisonDate=new Date() -1.year
}
numOfRecordsDeleted=tableName.where { dateField <=comparisonDate }.deleteAll()
log.info("deleted : " +numOfRecordsDeleted)
}
i'm successfully passing to this service the table name but i can't pass the date field , so how to get a specific property from a domain for example a domain named Payments got a property dateCreated , so i pass to my service Payments and dateCreated.
With where queries you have access to criteria query methods such as eq(), or in this case, le(). Those methods take the name of the property as an argument, which is what you need. I tweaked the code a bit because you're actually interacting with domain classes, not tables. Small distinction, until you start working with HQL.
def cleanDomainClass(String domainClassName, String dateField) {
def domainClass = Class.forName("some.package.$domainClassName")
def comparisonDate = use (TimeCategory) { new Date() -1.year }
def numOfRecordsDeleted = domainClass.where { le(dateField, comparisonDate) }.deleteAll()
log.info("deleted : $numOfRecordsDeleted")
}
How to add a String type field to class (i.e to all instances of that class), like grails add an id and version fields to all domain classes? If it is possible, how to specify the type of field as String / Long etc
EDIT:
The added fields are not updated in DB. how to make them persistent?
With respect to POGO, you can use ExpandoMetaClass to add/override a property/field/constructor.
class Foo{
String bar
}
//Add a field to Foo at runtime
//Type is set to String in this case
Foo.metaClass.baz = "Hello World"
//Add a method to Foo at runtime
Foo.metaClass.doSomething = {String str -> str.reverse()}
assert new Foo().baz == "Hello World"
assert new Foo().doSomething("Hello") == "olleH"
For your use case, you may be able to use normal inheritance:
abstract class Base {
// common fields
// constraints for those fields
// etc.
}
class MyDomain extends Base {
}
Maybe a silly question but where/how should I define default values for GORM domain class properties? For example when I'm creating a new Company object instance I want default value for property country to be "USA". I guess I could do it in create controller but it looks kinda dirty. Something like:
def create = {
def companyInstance = new Company()
companyInstance.properties = params
companyInstance.accepted = "USA"
...
Put it in the domain class itself
class Company {
String country = "USA"
}
Say I have something like:
class Foo {
static mapping = {
table 'foo_table'
}
}
How can I get the name of foo_table if I have a reference to an instance of this object?
Import org.codehaus.groovy.grails.orm.hibernate.cfg.GrailsDomainBinder.
To get the table name from the domain class:
def tableName = GrailsDomainBinder.getMapping(Foo).table.name
And to get the table name from an instance of the domain class:
def tableName = GrailsDomainBinder.getMapping(foo.class).table.name
JamesA's answer will work, but only if table name if defined explicitly, like in the question.
If you wish to get a table name whether or not it was specified in mapping, it can be done using SessionFactory:
def tableName = sessionFactory.getClassMetadata(Foo).tableName