I can't seem to figure out how to do memoization in Grails. According to the GPars docs it should be as simple as
def c = { x -> x*2 }.memoize() or ... .gmemoize()
But all i seem to get is compilation errors and stacktraces thrown. Has anyone successfully used gpars with grails?
Grails up until 1.4.0m1 bundled an old version of gpars (0.9) that didn't include memoization. Since Grails preferes the bundled libs to the user-specified ones, you never get a chance to see the memoization methods.
To my best knowledge the Grails master branch has already fixed that and gives users the freedom to choose a GPars version they like.
We are currently successfully using GPars data flow concurrency in a Grails 1.3.7 application. GPars is defined as a basic jar dependency in BuildConfig.groovy, we are not using the GPars Grails plugin.
Related
I have a grails 3 application that makes heavy use of plugins. Some of these plugins provide domain classes. My application will not start unless every plugin has the same gorm version. This is an annoyance for locally developed plugins, but can be a significant problem for using third-party plugins.
There are more details in the stacktrace, but the relevant parts appear to be:
Caused by: org.grails.core.exceptions.GrailsRuntimeException: Failed to introspect class: class (my class name)
at grails.core.ArtefactHandlerAdapter.isArtefact(ArtefactHandlerAdapter.java:129)
at grails.core.DefaultGrailsApplication.addOverridableArtefact(DefaultGrailsApplication.java:772)
at org.grails.plugins.AbstractGrailsPluginManager.registerProvidedArtefacts(AbstractGrailsPluginManager.java:310)
I am currently using Grails 3.2.8 with GORM 6.1.3.RELEASE, but this happens with other non-matching versions for gorm as well.
If there is a better way to accomplish the bigger-picture goal, my big-picture goal is to use the grails ehcache plugin (currently at 3.0.0.M1) which requires gorm 6.1.x as a minimum. Per conversations on that plugin github site, there is no problem using gorm 6.1 with grails 3.2.x, though this is not the default.
Is there any way to run a grails 3 application, using plugins which provide domain objects, in which these plugins have different minor versions of gorm?
In case anyone else comes across this, the answer was basically "no".
The longer answer is "not as long as the groovy version is changing in non-backwards-compatible ways", and apparently that happens a lot.
There are some comments from Graeme here: https://github.com/grails/grails-core/issues/10693 but to summarize: you have to use the same version of gorm across plugins, and also make sure any third-party plugins you rely on are on the same version. This is only required for plugins that provide domain objects, at least!
Need of help.
I am new to Grails,
My question is How to do db-reverse-engineer.?
I did it in Grails 2.5.1 but I am struggling with Grails 3.1.0.M2 version.
Thanks in advance.
There's no plugin for Grails 3. I started to convert the older one but it's more work than I was expecting because it has to work with Hibernate 4, and the old plugin only works with Hibernate 3.
But the generated files wouldn't be any different in Grails 3 than in Grails 2 since GORM has stayed rather consistent. Since the plugin is only used at build time, and often only once or at most a few times, I recommend that you configure a Grails 2 app with the same database config settings and using the plugin there, then moving the generated files to your Grails 3 app.
I've just recently started working with Grails, and I'd like to test out the Spring Security Plugin. I'm using Grails v3.0.0RC2, and I'm finding it difficult to come across accurate documentation for it with a lot of things.
I'm looking at the Grails page for the Spring Security Plugin, located at http://grails.org/plugin/spring-security-core, and it tells me to add the following to grails-app/conf/BuildConfig
plugins {
…
compile ':spring-security-core:2.0-RC4'
…
}
Now, Grails 3 has done away with the BuildConfig, and moved over to using Gradle. So I figured I could just that compile line to my "dependencies" section in build.gradle and it would work, like so:
dependencies{
...
compile:":spring-security-core:2.0-RC4"
}
However, that did not work. I get the error "Could not find :spring-security-core:2.0-RC4...".
Then I figured, 'Hey, it's a plugin, let me try prefacing it with "org.grails.plugins" like I see elsewhere in the build.gradle file:
dependencies{
...
compile:"org.grails.plugins:spring-security-core:2.0-RC4"
}
And still no go.
I have gotten it to compile by adding the dependency found on search.maven.org, like so:
dependencies{
...
compile 'org.springframework.security:spring-security-core:4.0.0.RELEASE'
}
But I don't think thats the proper way to do, because Grails documentation says I should have access to the command
grails s2-quickstart
once the plugin is installed, which I do not when I do it using the Maven repo.
I'm sure there's a simple configuration error I'm making, as I'm very new to both Grails, Spring, and Gradle, so I appreciate any help that can be provided.
The Spring Secuirty core plugin for Grails is not Grails 3 compatible. However, since Grails 3 is based on Spring Boot you can use the Spring Security Starter for Spring Boot instead.
This has been discussed on the Grails developers mailing list and going forward many Grails plugins will not be moved to Grails 3 and instead will be replaced by pure Spring solutions.
Update
Since this question was originally asked there has been a Spring Security plugin created for Grails 3.x. It can be found here: https://bintray.com/grails/plugins/spring-security-core/view
The "Spring Security Starter for Spring Boot" is a good starting point, but if you want to save yourself some time trying to figure out how to get it to work with Grails, check out this helpful blog post.
I wrote the blog post #Jamie referenced in his answer and I added a new blog post describing how to use the Gorm domain classes from Spring-Security-Core plugin from Grails 2.
dependencies {
...
compile 'org.grails.plugins:spring-security-core:3.0.4'
...
}
This is what I used and it worked for me
Does Grails 3.0.x no longer have the ability to create wrappers anymore?
The documentation doesn't seem to have the Grails wrapper section anymore.
Is there an alternative way which we can use the gradle wrapper to execute grails commands such as create-controller?
Does Grails 3.0.x no longer have the ability to create wrappers
anymore?
No.
Is there an alternative way which we can use the gradle wrapper to
execute grails commands such as create-controller?
Not for commands like create-controller, no.
We may re-introduce grailsw. File a feature request at https://github.com/grails/grails-core/issues if you would like to track that.
The Grails wrapper is back as of Grails 3.2.3:
http://docs.grails.org/3.2.x/guide/introduction.html#whatsNewGrailsWrapper
I have an app created with Grails 3.1.x, then upgraded to Grails 3.2.6, but the files such as 'grailsw' did not appear in my project root, and I'm not sure how to get them added via some command in the project.
When I create a new app using Grails 3.2.6, the new files are in the project root (grailsw, grailsw.bat, grails-wrapper.jar). I assume they can be copied over to an app like mine: a quick test of this worked for me.
I need to implement some simple aggregations in my app powered by Grails 1.3.7. The mongodb-plugin of 1.0.0.RC3 ships with gmongo 0.9.1, where the aggregate functions are not implemented.
How can I solve the problem? Are there any hooks to call java-mongo API directly, or maybe there's some other plugin releases which allow aggregations?
TIA
It seems that Mongo aggregation apis exist since 2.1 here, probably you might need to upgrade your libraries.
Here is the mongodb plugin documentation which is talking about accessing low-level api. For grails 1.3.7 take at this blog for details on how to add more recent mongo libs into your Grails application and this post seems to have the same issue.
Hope it helps.
Aggregations only work in GMongo 1.0+.
Well, it seems to be impossible to do it with the existing gmongo/mongo-GORM. There are too many version clashes: different mongo java drivers, different groovy versions etc. I saw many ClassNotFoundExceptions and alike.
Luckily I don't need the aggregation functionality right now, so I'll just wait and upgrade to grails 2.x and mongo-GORM 1.3++ later
So, I made it!
with a little amount of the blood shed, I found a way to use aggregations in gmongo 0.9.1 / mongodb 1.0.0.RC3 / Grails 1.3.7!
HOWTO:
you need to replace the mongo-java-driver with a newer version (I used the most recent for now 2.9.3). In Grails it looks like:
dependencies {
compile 'org.mongodb:mongo-java-driver:2.9.3'
}
In BootStrap or in my case Plugin-descriptor add the following line:
DBCollectionPatcher.PATCHED_METHODS << 'aggregate'
The aggregation invocation looks like:
def res = Task.collection.aggregate( [ $group:[ _id:'totalTime', time:[ $sum:'$time' ] ] ], [] as DBObject ).results()
and it works like a charm!