I have a object that i want to store for a moment. The object is in a controller for now, the controller will generate a view. A AJAX request is made from the view to next controller. For that moment i need the object previously stored. Previously, i used session and it worked well. But not sure it is the right thing to do. Is session the answer for this or is there anything else?
P.S. I need to access the data multiple time.
You can put your object to cache.
Add:
HttpContext.Current.Cache.Add("MyData", myObject, null, DateTime.Now.AddHours(6),
System.Web.Caching.Cache.NoSlidingExpiration, System.Web.Caching.CacheItemPriority.Normal, null);
Retrive object:
var my object = HttpContext.Current.Cache["MyData"] as MyType
Related
When a user Register, I want to add location data for the user.
I get those with GeoIP.
So, each time a user is created, I would like somewhere to add Country, City, etc.
I was thinking about setting Hidden fields in view, but I think it a hugly way to do it, and I'm sure there is a better way to do...
Any Idea???
Any time I create a record that needs extra data, involves inserting additional records into additional tables, etc, I create a service class. Something like "UserCreator" then I pass it the input, do any additional operations, wrap multiple database calls in a transaction and so on.
That said there are so many ways to do what you want. You could Input::merge(...) then save, you could separate the process of creating a user from your controller / route function, etc.
If you are just getting started with Laravel and/or your project is rather simple, then you probably want to look at Input::merge
I solved it using Request Contructor as said here in laracast
In the Form Request's constructor I inject \Illuminate\Http\Request. I can then add my value to the request instance as such:
public function __construct(\Illuminate\Http\Request $request)
{
$request->request->add(['date_of_birth' => implode('-', $request->only('year', 'month', 'day'))]);
}
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've been struggling with passing some value between controller.
I have one controller like this:
#RequestMapping(value = "/add", method = RequestMethod.GET)
public String addGet(HttpServletRequest request, #ModelAttribute(value="branch") Branch branch, Model model, blahblahblah)
//What I want to pass and re use:
String loadRespond;
try{
loadRespond= *SOME LOAD STRING METHOD*;
branch= branchManager.convertString(loadRespond); //METHOD TO SPLIT STRING & INDUCT TO OBJECT
}catch{exception){
//blabla
}
After I successfully inducted all the attributes into the object branch,i show them all through a binding form. What i want to do is, when i'm going to update the data/change some attribute, i want to compare the old branch to the new changed branch. This means that i have to pass the old branch object or the loadRespond string onto the POST method so that can be used. Do anyone have any idea of how to do this? Maybe to assign it to hidden type field in the jsp? and then use it on the controller with request mapping /add of method type post? Thanks..I'm a newbie..
Why don't you try out with session scope ?
store your old branch into the session . and when you get the new object compare with the old one (by retrieving from session)
You can save into session as any of both,
request.getSession().setAttribute("sessionvar", "session value");
#SessionAttributes("sessionvar")
A nice Example here to start with it.
Side-note : your question title doesnt quite expalain your problem and the solutions may vary
As San Krish notes in his answer the most common way is to use #SessionAttributes and pass objects/data using them.
This is useful if you don't worry about user moving backwards and forwards in a page, or want basic control of the object.
Now if you want to have a chain where controller 1 passes to controller 2 which may pass to controller 3 your best bet is to implement web flows.
Summary:
For short and sweet and quick: SessionAttributes is the way to go, example here http://www.intertech.com/Blog/understanding-spring-mvc-model-and-session-attributes/
For chain passing, greater control and validation use Spring Web Flows.
I'm pretty new to PHP programming and Magento. I wanna to pass the current ProductId from a form within a custom block to a controller (new action).
Yes I know that one method would be to add an input hidden (with my product id) in the custom block form and then to retrieve the Value through a regular:
$this->getRequest()->getPost('myvalue'))
Is there a better way in Magento to retrieve the value within the controller without having to declare extra secret input fields ?
Good for you for wanting to adhere to best practices within Magento! The passing of data to controllers is pretty standard, however. If we look at how the product is added from a product page, we'll actually see the product ID in the form action URL's parameters:
http://domain.com/checkout/cart/add/uenc/uenc_value/product/45573/
...where 45573 is the product ID. Of course this can also be sent to the controller via a hidden input field, which I use all the time. Note that the above is the same as http://domain.com/checkout/cart/add/?uenc=uenc_value&product=45573 in Magento.
Another way of storing data for use in controllers for future use is setting data into a session. For posting data to a controller I wouldn't recommend this method but it's something to keep in mind:
$session = Mage::getSingleton('core/session');
$session->setMyValue(true);
We can then retrieve the data from my_value later just by instantiating the session. Good luck!
Passing your data could be done in different ways :
You could use Magento's magic setters and getters.
So you would have to do this to set the value :
Mage::getSingleton('core/session')->setSomeVariable($value);
and this to retrieve it :
Mage::getSingleton('core/session')->getSomeVariable();
Or you could use the register.
Mage::register('key', $value); //to set your data
Mage::registry('key'); //to get your data
Magento provides a way to construct a URL with the necessary values, calculated against the configuration DOM. Blocks (and therefore block templates) can call Mage_Core_Block_Abstract::getUrl() directly:
$this->getUrl('some_handle/foo/test',array('id'=>'some_value'));
// Mage::getUrl() will work as well
The above would result in the following URL:
http://base_url/frontname/foo/action/id/some_value/
...which can be read in the FooController testAction() as
$this->getRequest()->getParam('id') // 'some_value'
i have a web application in Razor-MVC and the thing is this:
I have an Action that goes like every actions in MVC {controller}/{action}/{id}
Now... i have another action, that needs to return this view: return View("Xview") with the Model View too. The model view its not a problem, but the route i see when i do the return View("Xview") its like {controller}/{action} without the id... and i need that id in my route.
I know i can make a return RedirecToAction("Xview", new { id = idX }) but i need to use return View(...)
Edit:
The main issue because i need to return the view is because the ModelView in this action fills with temporal data... and in the Xview action, this ModelView its called from database and if i return RedirectToAction then the temporal data is lost, thats why i return View instead preserving my ModelView.
I hope you can help me with that,
Thanks!
Based on the edit to the question, I would say that the real issue is the state of the application. So instead of passing data between from request to request, use the Session object to store temporary results.
The route parameter is used for requests, not responses. Unless you redirect the user as part of your response, which turns out to be a new request.
If you want to return a View then pass any info you need as part of the model or in the ViewBag.
If you would like to reuses existing code (e.g. another action), then you will need to redirect with RedirectToAction.