a little question about erazor https://github.com/ciscoheat/erazor
i know this framwork is based on Razor template engine. http://weblogs.asp.net/scottgu/archive/2010/07/02/introducing-razor.aspx
i noticed the api doesn't fit exactly with Razor (ex: #for(a in p) differs from RAZOR)
this template system for haxe is very handy...
i just don't know how to setup a variable like we do in templo ( :: set mock="tada!":: )
//#scope is mycontroller;
#{var mock = scope.getMock()}
#if(mock!=null){
//display some html
}
any tips ?
thx
The following snippet works:
import erazor.Template;
import neko.Lib;
class Main {
static function main() {
var template = new Template("#{var mock = scope.getMock();} #if (mock != null) { #mock }");
Lib.print(template.execute( { scope : { getMock : function() return "hi" } } ));
}
}
What you missed is that inside a code block all the statements must be correctly closed (missing ;). Also erazor is loosely based on Razor and uses the Haxe syntax for expressions.
Related
I'm trying to style the currently active tab of my web project with the class "active". To target my tab elements I am using
onMount(() => {
const links = document.querySelectorAll(".topnav a");
});
I am then using a reactive statement to style the appropriate element like this
$: {
links.forEach((link) => {
if (link.getAttribute("id") === $page.url.pathname) {
link.classList.add("active");
} else {
link.classList.remove("active");
}
});
}
However, I have no way of sharing the links variable to my reactive statement. I also tried putting document.querySelectorAll inside my reactive statement (not using onMount at all), which worked flawlessly until i reloaded the page. What is the conventional approach to this?
You need to declare the variable outside of onMount so it is in scope of the reactive statement. E.g.
let links = null;
onMount(() => {
links = ...;
);
$: if (links != null) {
links.forEach((link) => {
});
Using document.querySelectorAll is not idiomatic Svelte.
Changing class (or other attributes) use the template syntax:
<a class:active={link.id === $page.url.pathname}>
{link.label}
</a>
If you really need access to the DOM api's Svelte has bind:this or action to get access to specific elements.
I tried the samples given in github griffon-master, also I tried the samples of the guide.
I would like to use javafx and groovy.
I would like to use fxml - thought of a scenario as that: fxml to set the stage, and for changes, use the groovy (set adjustment)
It seems that is not possible. I can use ("make it run"): javafx-java, read an fxml (with loadFromFXML), and the bindings are working. If using javafx-groovy, I can read an fxml, but with the javafx-class Loader (load), and bindings are not working (or it seems so).
Is it not possible at this moment, to use javafx-groovy and read-in fxml (via loadfromfxml)?
Could you post some sample code? Here's one example that makes use of the fxml node form GroovyFX
package org.example
import griffon.core.artifact.GriffonView
import griffon.metadata.ArtifactProviderFor
import javafx.scene.control.Tab
import org.codehaus.griffon.runtime.javafx.artifact.AbstractJavaFXGriffonView
#ArtifactProviderFor(GriffonView)
class Tab4View extends AbstractJavaFXGriffonView {
FactoryBuilderSupport builder
SampleController controller
SampleModel model
private AppView parentView
void initUI() {
builder.with {
content = builder.fxml(resource('/org/example/tab4.fxml')) {
inputLabel.text = application.messageSource.getMessage('name.label')
bean(input, text: bind(model.inputProperty()))
bean(output, text: bind(model.outputProperty()))
}
}
connectActions(builder.content, controller)
Tab tab = new Tab('Hybrid')
tab.content = builder.content
parentView.tabPane.tabs.add(tab)
}
}
This can be done. The trick is to make your Controller actions adhere to a stringent set of rules. The tldr is to make sure they return void.
Good:
def void save() {
Bad:
def save() {
The reason is found in the reflective analysis the Griffon framework uses to create its list of action targets. This list is generated in DefaultGriffonControllerClass.getActionNames(), which requires that:
Actions are subject to the following rules in order to be considered as such:
must have public (Java) or default (Groovy) visibility modifier.
name does not match an event handler, i.e, it does not begin with on.
must pass {code GriffonClassUtils.isPlainMethod()} if it's a method.
must have void as return type if it's a method.
value must be a closure (including curried method pointers) if it's a property.
The criteria defined in GriffonClassUtils.isPlainMethod() are as follows:
isInstanceMethod(method)
! isBasicMethod(method)
! isGroovyInjectedMethod(method)
! isThreadingMethod(method)
! isArtifactMethod(method)
! isMvcMethod(method)
! isServiceMethod(method)
! isEventPublisherMethod(method)
! isObservableMethod(method)
! isResourceHandlerMethod(method)
! isGetterMethod(method)
! isSetterMethod(method)
! isContributionMethod(method)
The list of action target names is subsequently used by AbstractActionManager:
#Nullable
private static Method findActionAsMethod(#Nonnull GriffonController controller, #Nonnull String actionName) {
for (Method method : controller.getClass().getMethods()) {
if (actionName.equals(method.getName()) &&
isPublic(method.getModifiers()) &&
!isStatic(method.getModifiers()) &&
method.getReturnType() == Void.TYPE) {
return method;
}
}
return null;
}
I have an application which can run scripts to automate certain tasks. I'd like to use meta programming in these scripts to optimize code size and readability. So instead of:
try {
def res = factory.allocate();
... do something with res ...
} finally {
res.close()
}
I'd like to
Factory.metaClass.withResource = { c ->
try {
def res = factory.allocate();
c(res)
} finally {
res.close()
}
}
so the script writers can write:
factory.withResource { res ->
... do something with res ...
}
(and I could do proper error handling, etc).
Now I wonder when and how I can/should implement this. I could attach the manipulation of the meta class in a header which I prepend to every script but I'm worried what would happen if two users ran the script at the same time (concurrent access to the meta class).
What is the scope of the meta class? The compiler? The script environment? The Java VM? The classloader which loaded Groovy?
My reasoning is that if Groovy meta classes have VM scope, then I could run a setup script once during startup.
Metaclasses exist per classloader [citation needed]:
File /tmp/Qwop.groovy:
class Qwop { }
File /tmp/Loader.groovy:
Qwop.metaClass.bar = { }
qwop1 = new Qwop()
assert qwop1.respondsTo('bar')
loader = new GroovyClassLoader()
clazz = loader.parseClass new File("/tmp/Qwop.groovy")
clazz.metaClass.brap = { 'oh my' }
qwop = clazz.newInstance()
assert !qwop.respondsTo('bar')
assert qwop1.respondsTo('bar')
assert qwop.brap() == "oh my"
assert !qwop1.respondsTo('brap')
// here be custom classloaders
new GroovyShell(loader).evaluate new File('/tmp/QwopTest.groovy')
And a script to test the scoped metaclass (/tmp/QwopTest.groovy):
assert !new Qwop().respondsTo('bar')
assert new Qwop().respondsTo('brap')
Execution:
$ groovy Loaders.groovy
$
If you have a set of well defined classes you could apply metaprogramming on top of the classes loaded by your classloader, as per the brap method added.
Another option for this sort of thing which is better for a lot of scenarios is to use an extension module.
package demo
class FactoryExtension {
static withResource(Factory instance, Closure c) {
def res
try {
res = instance.allocate()
c(res)
} finally {
res?.close()
}
}
}
Compile that and put it in a jar file which contains a file at META-INF/services/org.codehaus.groovy.runtime.ExtensionModule that contains something like this...
moduleName=factory-extension-module
moduleVersion=1.0
extensionClasses=demo.FactoryExtension
Then in order for someone to use your extension they just need to put that jar file on their CLASSPATH. With all of that in place, a user could do something like this...
factoryInstance.withResource { res ->
... do something with res ...
}
More information on extension modules is available at http://docs.groovy-lang.org/docs/groovy-2.3.6/html/documentation/#_extension_modules.
I would like to externalize all my string constants in my groovy classes to a properies file, and then have them called from there. I have seen the example with the configslurper, want to know how can I make the design such that I just include/import/load the resource/property file in my class and call the property I want to on it..
something like this in my controller
include/load propertyfilename
if (propertyfilename.propertyname == mygroovyVar) {
....some code
}
i.e if possible I want to avoid using "(quotes) when retrieving properties anywhere
like the resource bundle setup for properties in spring mvc
Regards
Priyank
You can do something like this:
something.groovy:
def loadConfig(environment,settingFileName) {
levelConfig = new ConfigSlurper().parse(new File(settingFileName).toURI().toURL())."$environment"
}
To access it :
def configFile = loadConfig("alpha","c:\somewhere\something.properties"
assert configFile.currlevel = "alpha"
something.properties:
alpha {
currlevel = "alpha"
}
beta {
currlevel = "beta"
}
prod {
currlevel = "prod"
}
If you dont want the environment tweak it a bit. Hope this can help.
As new to groovy...
I'm trying to replace the java idiom for event listeners, filters, etc.
My working code in groovy is the following:
def find() {
ODB odb = ODBFactory.open(files.nodupes); // data nucleus object database
Objects<Prospect> src = odb.getObjects(new QProspect());
src.each { println it };
odb.close();
}
class QProspect extends SimpleNativeQuery {
public boolean match(Prospect p) {
if (p.url) {
return p.url.endsWith(".biz");
}
return false;
}
}
Now, this is far from what I'm used to in java, where the implementation of the Query interface is done right inside the odb.getObjects() method. If I where to code "java" I'd probably do something like the following, yet it's not working:
Objects<Prospect> src = odb.getObjects( {
boolean match(p) {
if (p.url) {
return p.url.endsWith(".biz");
}
return false;
}
} as SimpleNativeQuery);
Or better, I'd like it to be like this:
Objects<Prospect> src = odb.getObjects(
{ it.url.endsWith(".biz") } as SimpleNativeQuery
);
However, what groovy does it to associate the "match" method with the outer script context and fail me.
I find groovy... groovy anyways so I'll stick to learning more about it. Thanks.
What I should've asked was how do we do the "anonymous" class in groovy. Here's the java idiom:
void defReadAFile() {
File[] files = new File(".").listFiles(new FileFilter() {
public boolean accept(File file) {
return file.getPath().endsWith(".biz");
}
});
}
Can groovy be as concise with no additional class declaration?
I think it would have helped you to get answers if you'd abstracted the problem so that it didn't rely on the Neodatis DB interface -- that threw me for a loop, as I've never used it. What I've written below about it is based on a very cursory analysis.
For that matter, I've never used Groovy either, though I like what I've seen of it. But seeing as no one else has answered yet, you're stuck with me :-)
I think the problem (or at least part of it) may be that you're expecting too much of the SimpleNativeQuery class from Neodatis. It doesn't look like it even tries to filter the objects before it adds them to the returned collection. I think instead you want to use org.neodatis.odb.impl.core.query.criteria.CriteriaQuery. (Note the "impl" in the package path. This has me a bit nervous, as I don't know for sure if this class is meant to be used by callers. But I don't see any other classes in Neodatis that allow for query criteria to be specified.)
But instead of using CriteriaQuery directly, I think you'd rather wrap it inside of a Groovy class so that you can use it with closures. So, I think a Groovy version of your code with closures might look something like this:
// Create a class that wraps CriteriaQuery and allows you
// to pass closures. This is wordy too, but at least it's
// reusable.
import org.neodatis.odb.impl.core.query.criteria;
class GroovyCriteriaQuery extends CriteriaQuery {
private final c;
QProspect(theClosure) {
// I prefer to check for null here, instead of in match()
if (theClosure == null) {
throw new InvalidArgumentException("theClosure can't be null!");
}
c = theClosure;
}
public boolean match(AbstractObjectInfo aoi){
//!! I'm assuming here that 'aoi' can be used as the actual
//!! object instance (or at least as proxy for it.)
//!! (You may have to extract the actual object from aoi before calling c.)
return c(aoi);
}
}
// Now use the query class in some random code.
Objects<Prospect> src = odb.getObjects(
new GroovyCriteriaQuery(
{ it.url.endsWith(".biz") }
)
)
I hope this helps!
I believe your real question is "Can I use closures instead of anonymous classes when calling Java APIs that do not use closures". And the answer is a definite "yes". This:
Objects<Prospect> src = odb.getObjects(
{ it.url.endsWith(".biz") } as SimpleNativeQuery
);
should work. You write "However, what groovy does it to associate the "match" method with the outer script context and fail me". How exactly does it fail? It seems to me like you're having a simple technical problem to get the solution that is both "the groovy way" and exactly what you desire to work.
Yep, thanks y'all, it works.
I also found out why SimpleNativeQuery does not work (per Dan Breslau).
I tried the following and it worked wonderfully. So the idiom does work as expected.
new File("c:\\temp").listFiles({ it.path.endsWith(".html") } as FileFilter);
This next one does not work because of the neodatis interface. The interface does not enforce a match() method! It only mentions it in the documentation yet it's not present in the class file:
public class SimpleNativeQuery extends AbstactQuery{
}
Objects<Prospect> src = odb.getObjects(
{ it.url.endsWith(".biz") } as SimpleNativeQuery
);
In the above, as the SimpleNativeQuery does not have a match() method, it makes it impossible for the groovy compiler to identify which method in the SimpleNativeQuery should the closure be attached to; it then defaults to the outer groovy script.
It's my third day with groovy and I'm loving it.
Both books are great:
- Groovy Recipes (Scott Davis)
- Programming Groovy (Venkat Subramaniam)