Normally messages from message properties are fetched via, key i.e. message code, What if we want to select more than one message property, like a list. To get a list of select message codes from message.properties, we need to customize messageSource bean. To do that, lets create a class ‘CustomisedPluginAwareResourceBundleMessageSource’ which should extend class ‘PluginAwareResourceBundleMessageSource’.

To fetch all properties we will use getMergedProperties().
 
 
 

import org.codehaus.groovy.grails.context.support.PluginAwareResourceBundleMessageSource

class CustomisedPluginAwareResourceBundleMessageSource extends PluginAwareResourceBundleMessageSource {
    List listMessageCodes(Locale locale, String lookupMessageCode) {
        Properties properties = getMergedProperties(locale).properties
        List listOfCodes = []
        properties.each {
            if (it.key.toString().matches(/^[\w.]*${lookupMessageCode}[.\w]*$/))
                listOfCodes.add(it.key)
        }
        return listOfCodes
    }
}

Here, ‘listMessageCodes()’ takes two parameters, first is the ‘locale’ we are looking in and second is ‘string’ which we are searching for ; and it returns the list of codes which contains that string.

Next we need to do is re-define ‘messageSource’ bean in the resources file:

import com.ig.demoApp.CustomisedPluginAwareResourceBundleMessageSource

beans = {
    messageSource(CustomisedPluginAwareResourceBundleMessageSource)  {
        basenames = "WEB-INF/grails-app/i18n/messages"
    }
}

That’s it!

All we need to do is call the method ‘listMessageCodes()’. Here is a small example.

Mentioned below is a sample of message codes, in message.properties:

fruit.orange.label=Orange
fruit.black.label=Black Grape
fruit.red.label=Red Apple
fruit.green.label=Green Apple

square.black.label=Black Square
square.yellow.label=yellow Square
square.red.label=Pink Square

circle.violet.label=Violet Circle
circle.magenta.label=Magenta Circle
circle.olive.label=Olive Circle

and a controller like:

package demoapp

class DemoController {

    def messageSource

    def show() {
        [fruits: messageSource.listMessageCodes(request.locale, "fruit"),
        squares: messageSource.listMessageCodes(request.locale, "square"),
        circles: messageSource.listMessageCodes(request.locale, "circle"),
        blackColorItems:messageSource.listMessageCodes(request.locale, "black"),
        redColorItems:messageSource.listMessageCodes(request.locale, "red")]
    }
}

a gsp:

<g:form>
    <p>Available Fruits</p>
    <g:each in="${fruits}" var="fruit">
        <span>
            <input type="radio" name="fruit">
            <label><g:message code="${fruit}"/></label>
        </span>
    </g:each>

    <p>Available Squares</p>
    <g:each in="${squares}" var="square">
        <span>
            <input type="radio" name="square">
            <label><g:message code="${square}"/></label>
        </span>
    </g:each>

    <p>Available Circles</p>
    <g:each in="${circles}" var="circle">
        <span>
            <input type="radio" name="circle">
            <label><g:message code="${circle}"/></label>
        </span>
    </g:each>

    <p>Available Black Color Items</p>
    <g:each in="${blackColorItems}" var="blackColorItem">
        <span>
            <input type="radio" name="blackColorItem">
            <label><g:message code="${blackColorItem}"/></label>
        </span>
    </g:each>

    <p>Available Red Color Items</p>
    <g:each in="${redColorItems}" var="redColorItem">
        <span>
            <input type="radio" name="redColorItem">
            <label><g:message code="${redColorItem}"/></label>
        </span>
    </g:each>

</g:form>

That’s it :)

• You can also find the demo here.