Show enum values on GSP page and then bind them in the database

grails enums gsp

12,218

Solution 1

This is how I have done it in the past. This way you have i18n support.

gsp

<g:select name="duration" from="${MyEnum.values()}" valueMessagePrefix="ENUM.MyEnum" />

messages.properties

ENUM.MyEnum.MIN15=15 Minutes
ENUM.MyEnum.MIN30=30 Minutes
ENUM.MyEnum.HOUR1=1 Hour
ENUM.MyEnum.HOUR2=2 Hours
ENUM.MyEnum.HOUR5=5 Hours
ENUM.MyEnum.HOUR8=8 Hours
ENUM.MyEnum.HALFDAY=half day
ENUM.MyEnum.FULLDAY=full day

Solution 2

<%@ page import="fully.qualified.path.MyEnum" %>

Try this at the top of your GSP (with the fully qualified path adjusted to your packages, of course).

Edit (this should work (your enum syntax is wrong too)):

<%@ page import="ENUM.MyEnum" %>
<html>
<head>
</head>
<body>
<g:select from="${MyEnum.getAllEnumList()}" optionValue="displayName" name="duration"/>
</body>
</html>

And then the revised class:

package ENUM

public enum MyEnum {

    MIN15('15 Minutes'),
    MIN30('30 Minutes'),
    HOUR1('1 Hour'),
    HOUR2('2 Hours'),
    HOUR5('5 Hours'),
    HOUR8('8 Hours'),
    HALFDAY('half day'),
    FULLDAY('full day')


    private final String displayName

    public static final List<MyEnum> getAllEnumList() {
        [MIN15,MIN30,HOUR1,HOUR2,HOUR5,HOUR8,HALFDAY,FULLDAY]
    }

    public String toString() {
        return displayName
    }

    MyEnum(String displayName) {

        this.displayName = displayName;
    }
}

Edit2:

The easiest way to avoid the whole thing (both the second answer here and my solution) is to simply pass off the value list to the gsp from the controller. Simply add

[duration:MyEnum.values()]

or something similar to your controller return.

Solution 3

You can avoid importing in your GSP (which is kind of ugly) if you use a custom tag library. You'll also need to add another method (getKey()) to your enum if you want to have the option key be different from its value.

MyEnum.groovy

enum MyEnum {
    MIN15('15 Minutes'),
    MIN30('30 Minutes'),
    HOUR1('1 Hour'),
    HOUR2('2 Hours'),
    HOUR5('5 Hours'),
    HOUR8('8 Hours'),
    HALFDAY('half day'),
    FULLDAY('full day')

    final String displayName

    private MyEnum(String displayName) {
        this.displayName = displayName
    }

    String getKey() {
        name()
    }

    String toString() {
        displayName
    }
}

MyEnumTagLib.groovy

// add import if MyEnum is in a different package

class MyEnumTagLib {
    static namespace = 'my'

    def enumSelect = { attrs ->
        attrs.from = MyEnum.values()
        attrs.optionKey = 'key'
        out << g.select(attrs)
    }
}

gsp

<my:enumSelect name="duration"/>

12,218

Nikhil Sharma

Updated on June 09, 2022

Comments

Nikhil Sharma almost 2 years

I have a use case in which I need to first show the value of enum on the GSP page first as a drop down list, have the user select one of those values and then finally bind the data to the domain.

So my code on GSP looks like my enum is MyEnum

<g:select from="${MyEnum.getAllEnumList()}" optionValue="name" name="duration"/>

my enum is

public enum MyEnum {

    MIN15('15 Minutes'),
    MIN30('30 Minutes'),
    HOUR1('1 Hour'),
    HOUR2('2 Hours'),
    HOUR5('5 Hours'),
    HOUR8('8 Hours'),
    HALFDAY('half day'),
    FULLDAY('full day')

    private final String name
    private final String displayName

    public static final List<MyEnum> getAllEnumList() {
        [MIN15,MIN30,HOUR1,HOUR2,HOUR5,HOUR8,HALFDAY,FULLDAY]
    }

    public String toString() {
        return displayName
    }

    MyEnum(String name,String displayName) {
        this.name = name
        this.displayName = displayName;
    }

}

when I hit the page its showing an error like:

Error processing GroovyPageView: Error executing tag <g:form>: Error evaluating expression [MyEnum.getAllEnumList()] on line [37]: java.lang.NoClassDefFoundError: Could not initialize class ENUM.MyEnum at D:/myspace/projects/IcepushpluginSampleApp/grails-app/views/util/test.gsp:46

Any ideas ????

Nikhil Sharma over 12 years

<%@ page import="ENUM.MyEnum" contentType="text/html;charset=UTF-8" %>
Oliver Tynes over 12 years

First of all, your syntax is wrong, the UPPERCASE stuff is a variable name, not a parameter. So you can remove the name part. Secondly, your dont need to add the contentType attribute for importing classes. Thirdly, it works here when I test with your classes, will update answer with a gist.
Dónal over 12 years

You need to import the enum class, not the enum constant <%@ page import="fully.qualified.path.MyEnum" %>
Dónal over 12 years

@Oliver the getAllEnumList() method is redundant, every enum already provides a values() method that does the same thing
Oliver Tynes over 12 years

Yup, I know, I just wanted to show him what modifications I did to his class, good to mention it though.