– – where be dragons
– – where be dragons
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gum-2013-where-be-dragons
GroovyMN August 2013 Presentation SlidesOn Github aaronhanson / gum-2013-where-be-dragons
where be dragons
pragmatic grails development
Uses For Grails
Rapid Protoype Development
grails generate-all
Enterprise Development
grails install-templates
grails create-controller
setProperties() & command objects
def user = User.get(id)user.properties = params
slightly better
def userCommand = new UserCommand(params)def user = User.get(id) // still insecure probablybindData(user, params)
Grails 2.3 (new, but similar)
@Transactionaldef update(User user) { .... user.save flush:true ....
}
Fat Controllers
Making Database Calls In The View Layer
Prototyping you might do this:
<g:select name="states" from="${State.list()}"/>
But you should probably do this instead:
class FooController { def list() { // ... [states: States.list()] }}
<g:select name="states" from="${states}"/>
GOTCHA!
<g:each in="${customer.phoneNumbers.sort()}" var="phoneNumber">
GSPs
Use more templates
Use more taglibs
Be mindful of the need to
.encodeAsHTML()
.encodeAsURL()
g:* tags will do it for you
roll your own or output from model directly,
you're own your own
Domain vs Concept
Controllers/Services
OK For CRUD Applications
ProductController
ProductService
Product
Better For Other Applications
CatalogController
ShoppingService
Making everything a service
You're lazy. So am I.
Why do we often create services for everything?
class FooService { def barService ...}
Not everything needs to be a service.
Libraries with good old fashioned functions are OK too.
src/groovy
Try to keep your app out of your libraries.
smart domains
Quit using your domain classes as services.
Domain instances should operate on the things they know about.
If you need to look up information or do more logic, use a service.
Services are good to funnel calls and add things like caching.
Think about DomainClass.* as DB.*
Foo.executeQuery('select * from Bar where id = 1')
Doesn't have anything related to Foo. Smell.
Injecting services in your domains
Why?
Is it really a service or is it a library?
Perhaps you're trying to do too much?
Testing can be difficult
Code coupling possibility higher
Making Everything Transactional
Stop it!
custom urlmappings
testing
phases vs test type
unit - fast
integration - slow
functional - slow
Quit writing unitegration tests
(yes I made up a word)
dbcreate vs migrations
Time Left?
Package naming/Plugins
Questions/Heckling?