Grails - how execute code before every save?

Question

Is there a good/standard way to execute some common code before every save() invocation on domain classes?

For example, my domain

class Page {

    String url
    Boolean processed
    Date date
    Integer urlCrc 
}

My form has only 3 first fields and I would like to calculate urlCrc every time the save() method is called. I cannot just override save method because it is injected.

Solution 1

You can use GORM events - see the docs. Since by default validate() is called before every save() I would use that.

class Page {
    //your defs here

    def beforeValidate() {
        this.urlCrc = yourComputationHere
    }
}

Solution 2

class Page {
    def beforeInsert() {
        this.beforeUpdate()
    }
    def beforeUpdate() {
        this.urlCrc = 'calculate something'
    }
}

Solution 3

This topic is covered in the GORM docs:

6.5 Advanced GORM Features

6.5.1 Events and Auto Timestamping

Comments

[mrok]

Thanks, it works. Unfortunately grails.org is down, due to some routing problems grails.1312388.n4.nabble.com/… so I needed ask here

[sf_jeff]

The above solution is probably best, but another option is to use a grails calculated field. See the docs for that.

[IgniteCoders]

If you want to execute the code before the save use beforeUpdate() / beforeInsert(). if you use beforeValidate() that it's called always when you call validate() (method save() call 'validate()' before save). So your code it's executed before validate even if you don't save.

[dopatraman]

can you link to the documentation on this?

[IgniteCoders]

Yes, this is the documentation