I have a task in my controller that I call from an URL in the view, like this:
echo JRoute::_('index.php?option=com_mycomponent&task=myComponent.myFunction');
The task gets the model and actions one of the model's methods, which should return a list of objects based on state variables set from a form in the view's POST. It seems when I click the anchor and the task is loaded - the state disappears.
Can anyone tell me why?
Many Thanks!
Since it is a new request your post data is no longer available.
You need to store information in session (setUserState) or somewhere else (db?) if you want to keep it across calls.
setUserState is a convenient feature of Joomla to store (small) pieces of info into session in an easy way: http://docs.joomla.org/How_to_use_user_state_variables
Related
Spring MVC 4.1
Hi,
I have a situation where, on a single page, there are several input fields. As the users enters numbers into these fields, a bunch of calculations will occur and update various other fields on the page.
I want this whole calculation model to take place in Java on the server-side. I really want to avoid replicating this logic in Javascript on the client.
What I envision is...
User opens the page, the object that does the calculations (let's call it Calculator) is created and its initial state is set (many of its fields are pre-populated with values).
This Calculator instance is stored and available for the duration of the user's time on that page.
Whenever the user changes a value in an input field, that new value is sent to the server via ajax and plugged into our Calculator object. The Calculator, re-calculates the other fields based on the new state and returns the results to the page.
The other fields on the page are updated accordingly.
The key here is that I'm not sending the state of all fields with each ajax request. I'm only sending the current value that was updated. Essentially, I'm trying to ensure that the form state and the Calculator state on the back-end are always synchronized.
I have looked into #SessionAttributes and #ModelAttribute.
The problem with #ModelAttribute, as I understand it, is that it will be re-created with each ajax request.
The problem with #SessionAttributes is that it is a session variable. What if the user has two of these windows open? And how do I ensure the object is removed from the session when they leave the page? etc...
Maybe there's no magic Spring bullet and I just have to figure out the session variable thing. But any pointers on dealing with this would be much appreciated.
Thanks!
You have a couple of options:
.1. Like you have said using the #SessionAttributes, however yes it suffers from the issue that you have mentioned, multiple instances of the same session will see the same variable.
.2. Store state somewhere else and re-hydrate the state using #ModelAttribute annotated method. I would personally prefer this approach, essentially when you create the form, create it with a identifier for the current state:
#RequestMapping(params = "form")
public String createForm(Model uiModel) {
uiModel.addAttribute("calculationId", UUID.randomUUID().toString());
return "calculationpage/create";
}
Then for subsequent ajax requests, ensure your previous calculationId is sent across:
#ModelAttribute("calculationState")
public CalculationState rehydrateState(String calculationId) {
//retrieve current state of calculation from some persistent store..
}
#RequestMapping("/calculate")
public String handleCalculation(#ModelAttribute("calculationState") CalculationState c) {
//you will get a calculationstate with the delta's at this point..
}
.3. Another potential approach may be to use session but disambiguate different instances within the session with a custom id:
public String handleCalculation(HttpSession session, #RequestParam("calcId") String calcId) {
CalculationState calcState = (CalculationState) session.getAttribute("calculation" + calcId);
}
You need any sort of persistent store outside session to store and retrieve the state of your calculator model. Like Biju said, I will go for solutions like No 2.
I'm asking what is the best strategy for filtering with Symfony2.
I want to filter a table of entities (hotels). This filter should allow me to :
choose hotels with or whitout email, with or without web site etc.
choose hotels based on state and/or city (relation OneToMany)
choose what information I want to display on the table with checkboxs (for example display "email adress" on the hotel table, but do not display "tel" or "web site").
First I think to build the filter form on the HotelController. When the filter is submitted, I had a FlashBag for every $_POST sended, redirect to the same page, and if there are FlashBag I send cookies to the $reponse. Then I display the table filtered with data who are on the cookie.
But I dont't really like this, cause I had a very big indexAction() on the HotelController, and I think it'as not really clean to change $_POST to FlasBag to Cookie, is it ? I do this redirection, cause by refreshing the page, data are not posted again.
I'm also asking a question, to prevent a too big IndexAction() method, can I put some code to another method, for exemple a method PostToFlashBag() and another FlashBagToCookie(), or every method on a Controller has to end with the word "Action" and must be accessible with the router ?
Then, I think to another thing : had an entity "Filter", with every row I need. For exemple "WithEmail", "DisplayTel" etc.. Then I can build a FilterType easily, and update the Filter entitie, to redirect to the same page (again, to prevent reposting data if the user refreshes the page). Finally, I can display the table with the object Filter, with a method on the HotelRepository.
That seems great, but I'm a little worry because the filter entity will only have one entry, and I have to find the Filter(1). Due to MVC, is it correct to have a model with only one entry ?
What strategy would you choose (maybe another one) ? I'm interesting to learn good practice with MVC and Symfony2 devloppemnt.
Having a dedicated model class - let's call it Filter - that will receive the values input by the user, is definitely the way to go.
More over, use the Symfony2 form on this input, so you can have validation, and be sure that the withEmailis trully a boolean, etc. From you Filter, build you SQL/Doctrine query and return what your controller have to return, be it a view, or raw datas.
You can have any method you want in a controller. After all, controllers in Symfony2 are plain old PHP objects. They only have to implement ContainerAwareInterface. Usually they inherits Controller, but this inheritance only brings some proxy methods, like getDoctrine or render.
The only convention is that methods which are used as route must end with Action
I have this menu that I want to make available on my layout (essentially every view on my site). I want to maintain the menu's state (whether or not tree items are opened or closed) across page requests. What I want to do is possibly have a child action that is called from my layout page that grabs some cookie or session info which contains the tree's state information so I can rebuild the tree exactly how it was the last request. My problem is, from what I read, it's bad practice to call things like Session and Cookie from within ones controller actions. What I'd like to know is what's a more elegant way to solve this problem. If I must use Cookie and Session, anyone has ideas on how to mock them? Thank you
My problem is, from what I read, it's bad practice to call things like
Session and Cookie from within ones controller actions
Interesting. And did the author of this article explain why it would be a bad practice? There's nothing wrong accessing the session and cookies from your controller actions. Actually using the session for this kind of things might not be suitable because if the user closes his browser you will not be able to persist the layout of the tree whereas with persistent cookies that would be possible.
We can have the Menu as a Partial View.
The Action to Render Partial view will accept parameters to render the state.
Each link will invoke the action with different parameters.
for Example,
public PartialViewResult RenderNavigation(int Menuroot, int subMenuItem)
{
IList<MyNavigationItem> navigationItems=GetNavigation();// Some method that'll read nvigationitems.
navigationItems.Where(n=> n.menuId.Equals(Menuroot) ||n.IsOpen.Equals(subMenuItem)).ToList().ForEach(i=> i.IsOpen=true);
return View("SomeMenuView",navigationItems);
}
public class MyNavigationItem{
int menuId{get;set;}
bool IsOpen{get;set;}
int parentMenuId{get;set;} // set default -1 for Root Items
}
I have some property OwnerId that has each page in my application. I need these property to create HttpWebRequest and get some data. But when the application deactivated and activated again the page as deleted and created again, so these property is 0. I can't save these property in PhoneApplicationPage.State , because these property is different for different pages, so when I go twice back I can get error. I think to take it property after application activated from NavigationService.BackStack pages.But I'm not sure it is right. How can I do it ?
Aram .. thanks for explaining the question better.
Now, while your application is in the foreground, how are you managing all these different OwnerIDs? A collection? I am guessing you don't have multiple instances of the same page; but rather pass query parameters along to indicate which OwnerID/UserID should be used to display appropriate user info. You could put the whole collection in State dictionaries with a key & hydrate/dehydrate during the application lifecycle. Makes sense?
Thanks!
I'm not 100% clear on whether you need a setting for each page or just a single setting for the app. In either case your best option (IMO) is IsolatedStorageSettings (http://msdn.microsoft.com/en-us/library/system.io.isolatedstorage.isolatedstoragesettings(v=vs.95).aspx)
If you just need a single setting then there's no problem but if you need one for each page you will need to do something ugly like using the page name as the key.
I know that we can design the layout in *.xml then in the action just invoke loadLayout, and renderLayout to render the blocks/views.
But, I have a question is:
- How can I load the layout at runtime?
If we have an action which does not really design its layout and will be decided how to render at runtime.
You can please consider the answer from the question for more clear.
Writing a new answer because it seems that you actually DO still want to render, you just want to render a different route's layout XML updates. I believe the _forward() method from Mage_Core_Controller_Varien_Action will allow you to do what you are describing with the least amount of pain.
You should add your action controller directory ahead of the catalog directory, create a ProductController with a viewAction, and check customer is not logged in - in this check you would call $this->_forward('customer','account','login');.
This approach though is going to require more effort in order to be usable, as I imagine that you want the user to be sent to the product page upon login. Have you seen Vinai Kopp's Login Only Catalog module? It should do this for you.
loadLayout() and renderLayout() just execute block output method toHtml() (usually) and take the resulting strings and apply them to the response object via appendBody(). In an action controller you can just call $this->getResponse()->setBody('response string'). How you build the string is up to you.
You can also use Mage_Core_Block_Flush to immediately send output to the browser without using the response object.