ThymeLeaf newb question here: I would like to register a custom SpEL utility object to provide some custom formatting. The Spring EL documentation says that I should use StandardEvaluationContext.registerFunction() to do this, which is great and all, but I want this to be available for use in all SpEL functions in my ThymeLeaf templates. I figure that this is done in the servlet context XML, but I have no clue how to go about it and I can't find ThymeLeaf documentation that explains how to do it.
StandardEvaluationContext.registerFunction() is used to assign an identifier with a method and then use it to call that method from your SpEL expressions.
But Spring EL also allows you to call methods on any objects in the context. So if all you need is to make some helper object methods accessible for your SpringEL expressions to call, all you need to do is just put an instance of that helper class to the evaluation context.
Related
How to call a method in Camel Route using Java DSL? I want to get a compile time error in Eclipse if I am using the wrong signature for method.
.bean(Foo.class, "setDetails("1", "Camel")")
Here I won't get compile time error for the wrong method signature as method was defined in string.
This is, as far as I know, not possible because Camel calls the method through reflection API.
What you can do, is to create constants in Foo.class with the method names and then use the constants in the bean calls instead of the hard-coded method name Strings.
But even then, you are of course able to rename a method in the bean without adapting the constant. The functionality would be broken but the compiler would be still happy.
If the bean is dedicated to Camel routes and under your control, the best you can do is to refactor the bean.
Remove the method parameters, set them on the message exchange and inject them with #Header, #Property
Split the bean into very small beans with only one method to get rid of the method names
Try this
.bean(Foo.class, "setDetails(1, 'Camel')")
If your first parameter is of type int just put the number without quotes
Second parameter is String, so you should put String to single quotes.
According to the docs, from camel 2.9 onwards, you can do pass in an integer and a string as parameters in a method call (using your example) like this:
.bean(Foo.class, "setDetails(1, 'camel')")
OR
.to("bean:Foo?method=setDetails(1, 'camel')")
If I understand the question correctly, you want a compile-time error about something that is evaluated at runtime. This is simply not possible.
Is there any thing exist which I could do in service but not in factory or vice-versa? Basically I want to conclude the difference between the service and a factory.
you can take a look at a the new post .service() versus .factory(), the actual answer. by #ToddMotto
So, what is a service?
A Service is just a function for the business layer of the application, it’s just a simple function. It acts as a constructor function and is invoked once at runtime with new, much like you would with plain JavaScript
Factory
Next, the confusing .factory() method. A factory is not just “another way” for doing services, anyone that tells you that is wrong. It can however, give you the same capabilities of a .service(), but is much more powerful and flexible.
A factory is not just a “way” of returning something, a factory is in fact a design pattern. Factories create Objects, that’s it. Now ask yourself: what type of Object do I want? With .factory(), we can create various Objects, such as new Class instances (with .prototype or ES2015 Classes), return Object literals, return functions and closures, or even just return a simply String. You can create whatever you like, that’s the rule.
Enjoy
We're updating code to use Autofac. We'd like to use custom delegate types to define factories instead of Func's. But we also use an obfuscator, which renames parameters. We'd like to tell the Autofac container to match by type instead of name as it does with Func's. Is this possible?
On the official documentation of Autofac, you have this information
By default, Autofac matches the parameters of the delegate to the parameters of the constructor by name. If you use the generic Func types, Autofac will switch to matching parameters by type.
http://docs.autofac.org/en/latest/advanced/delegate-factories.html
Could you customize the obfuscator to use the same name for the parameter name of the delegate and the constructor?
As mentioned, the way to do it right now is to use Func. Even if it were possible with just delegate factories, Autofac won't know what to do when there are two parameters of the same type. Here's my answer to a very similar question.
Thanks guys. We ended up creating a custom registration source using Autofac's source as a guide. In our testing, if there are two parameters of the same type, it appears to fall back to order.
I'm stuck with a very simple issue - calling functions between classes. Say I have a function (renderMap) in one of my already defined class: App.ux.MyClass (I also added this class to 'requires' in app.js). How to call the 'renderMap' function from other classes?
I tried App.ux.MyClass.renderMap() but I got 'undefined is not a function'.
I would solve the problem by creating a mixin that would contain all functions shared by many classes. See the mixins docs for details.
Then you would just call
this.renderMap()
in any class that uses that mixin.
I think it's problem in application architecture.
You can to use DI (it will be best choice), but, if you cannot, try to create Singleton or ServiceLocator patterns (yes, I know they are anti-patterns).
In ExtJS 4.x and Sencha Touch 2.x Singleton can be created via statics definition in class. Read more: http://docs-origin.sencha.com/touch/2.3.2/#!/api/Ext.Class-cfg-statics
Then, you just can to call method like App.ux.MyClass.methodName().
I want to perform custom logic in an IdempotentConsumer. I've extended the class and implemented the logic. How can I add this to my route?
Do I have to make my own Definition class? Do I add it as a Processor? How do I get the parameters passed to the constructor?
Well, custom consumer/producer could be little overkill. I think for some kind of custom logic is enough to do it trough processor or custom bean.
1.Bean
Look at bean binding you can use simple language to pass arguments to your method. It will looks like this:
.bean(OrderService.class, "doSomething(${body}, true)")
.to("bean:orderService?method=doSomething(null, true)")
2.Processor
You have to realize your classes should be stateless because of concurrent matter of camel framework. Your constructor should be empty and your variables final otherwise whole bunch of magic could happen. Everything you want to pass to your logic component/processor should be passed via Exchange object. You can store your variables in getin() or getOut() messages as headers or body or Exchange properties and pass it to next endpoint. The exchange will change dynamically as it flows trough you camel routes. It should be your one and only one mutable object.