So I have a dynamic form that I created with thymeleaf and everything submits just fine to the database, however the child object, which in this case is row, is not being saved to the parent studySet. When I'm in debug mode I can see that the studySet contains an arraylist of however many row objects, but when they're being saved, it's just not being set to the studySet object.
I'll show some code, to see if I'm forgetting to do anything here. If anyone can see my problem and let me know that would be great. Thanks in advance
Here's my post method in my controller
#RequestMapping(value="createStudySet", method=RequestMethod.POST)
public String createSetPost (#ModelAttribute StudySet studySet, ModelMap model, #AuthenticationPrincipal User user) {
studySet.setUser(user);
user.getStudySet().add(studySet);
List<Row> rows = studySet.getRows();
studySet.setRows(rows);
studySetRepo.save(studySet);
return "redirect:/answers";
}
Also this may be helpful, this is a screenshot of my controller in debug mode, so that you can see that there is rows in the studySet.
So, I just want to set those rows to the studySet. Also I realize that this code is probably useless, but it shows an attempt at what I'm trying to do. List<Row> rows = studySet.getRows(); studySet.setRows(rows);.
Also let me know if it would be useful to see my domain objects, and I would add those to the question.
Related
I am trying to build sth pretty simple, but I try to do it the correct way. But I struggle to figure out what is best.
I have a process chain where the user has to fill in some fields in different forms. Sometimes it depends from the user inputs which form the user is shown next.
[HttpGet]
public IActionResult Form1(Form1Vm f1vm)
{
return View(f1vm);
}
[HttpPost]
[ActionName("Form1")]
public IActionResult Form1Post(Form1Vm f1vm)
{
//process the data etc
//prepare the new viewmodel for the next form view (f2vm)
//Option1:
return View("Form2", f2vm);
//Option2:
return RedirectToAction("Form2", f2vm);
//for Option 2 I would need an additional HttpGet Action Method in which I
//would have to call Modelstate.Clear(); in order to not have the
//immediate validation errors on page load
//also all the properties of my viewmodel are passed as get parameters
//what looks pretty nasty for me
}
//More form views action methods should be added here...:
What is the better way? As mentioned in my comments above I have quite a big disadvantage for using the RedirectToAction option. However if I use the direct View(); call, I don't take care on https://en.wikipedia.org/wiki/Post/Redirect/Get and the user cannot simply refresh a page without getting a warning that his form is submitted once again.
Do I miss another way or don't see something obvious?
Edit: I just thought about a 3rd way, which I have seen quite often: Not transfering the whole VM to a HttpGet method but only the ID. I'd then have to load all the data stored previously directly from the db, map it again to my new VM and then call the View(); with this VM. Right now I think this is the "best" solution, however I feel like it is pretty laborious...
As per the dicussions, I would suggest using depending on your preference :
1) Save to db at the end of each form post and as you suggested use the I'd to redirect to a GET.
2) Depending on the the number of form pages and your requirements, retrieving values that a form needs on the get would be standard practice. This ensures that if a user drops off a form at any stage you can then start them off where they left off.
3) I wouldn't setup the viewmodel for the next form in the post of the previous. Generally as part of the single responsibility principle you want to ensure that your methods have only one reason to change.
4) PostRedirectGet pattern should be implemented with this to ensure data is not saved multiple times if a user refreshes after a post.
After creating a model and adding it to a repository I want to have the new ID for different purposes (creating a mail, updating other fields outside the Extbase world)
$page = t3lib_div::makeInstance('Tx_MyExt_Domain_Model_Page');
$page->setTitle('Hello World');
$this->pageRepository->add($page);
At this point $page hasn't got an ID yet, uid is null.
$page->getUid(); // returns null
When does it get it? And how can I retrieve in on runtime?
In ExtBase, objects are "managed". This means every persistence transaction (add/remove/update) is simply noted in the underlying logic, but not yet executed until the appropriate time (like the end of processing a request). So, just because you add an object to a repository doesn't mean that it's actually added yet. That actually happens once $persistenceManager->persistAll() is called, which isn't something you need to do manually, ever. The point is, your $page object won't have a UID until it's saved and that's why $page->getUid() returns null. Look here for a great explanation.
I suspect that you are trying to do something outside of the ExtBase object/MVC lifecycle. At least, last time I got null when I tried to get the UID of an object, it was because I wasn't operating within the framework appropriately.
However, if you post some more code and give us a bigger picture of what you're trying to achieve, maybe we can help you get to a point where that object actually has a UID. For instance, if you're in a Controller object, tell us which Action method you're in, or if you're in a Repository object, tell us what you're trying to get from the repository and where/how you plan on using the query results.
EDIT
Just guessing here, but I'm assuming you're executing this code in some action of a controller. Since after the controller is executed a view is rendered, you can just pass the page object to the view:
$this->view->assign('page', $page);
And then in your view you can use the page object in a link:
<f:link.action action="show" arguments="{page:page}">
See this page object
</f:link.action>
And then in the show action of your controller you can show the page:
public function showAction(Tx_MyExt_Domain_Model_Page $page) {
// Do whatever you need to show the page in the `Show.html` template
}
I really am just guessing here. If you can give us a larger picture of what you're trying to do, what your action methods are supposed to do and things like that, we can answer your question a little more confidently.
(I'm also assuming that your page object isn't a replacement for the regular TYPO3 pages and that they are something totally different. It's much easier to deal with those TYPO3 pages through the backend interface than at the php level.)
You can call persistence manager explicitly in Your controller like this
#TYPO3 4.x
$persistenceManager = $this->objectManager->create('Tx_Extbase_Persistence_Manager');
$persistenceManager->persistAll();
#TYPO3 6.x
$persistenceManager = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\CMS\Extbase\Persistence\Generic\PersistenceManager');
$persistenceManager->persistAll();
I just noticed that on one page of my site, where I pass a ViewModel to my View page, NHProf is giving the following warning:
This statement executed from the view, which can result in bad performance and/or brittle behaviour.
It then links to this page: http://nhprof.com/Learn/Alerts/QueriesFromViews
My ViewModel consists of just 2 properties:
public IEnumerable<Photo> Photos { get; set; }
public Photo SelectedPhoto { get; set; }
I assign the photos to this ViewModel within my Controller as follows:
PhotoViewModel myViewModel = new PhotoViewModel();
myViewModel.Photos = entity.Photos;
My View obviously inherits this type, and aside from outputting a header (which makes use of the SelectedPhoto object), it just loops through each of the Photos rendering some content for each of them.
NHProf shows the 'problem' query as being where it retrieves the collection of Photos that I'm looping through in my view, though I'm not explicitly telling it to go off and get those records from within my view - I've passed those records within the Photos property of my ViewModel.
I have other pages where I don't need to pass a ViewModel and I simply pass IEnumerable<Photo> to the View, and then render the markup exactly the same as I do in the problem view, and NHProf gives no warnings (as there shouldn't be) in that scenario.
I'm thinking maybe it's related to Lazy Loading, and because my collection is part of a ViewModel, when I go to loop through the Photos property within the ViewModel type, it goes to get those records at that point?
Does anyone have any idea what is happening here? The site functions perfectly, but NHProf just sees that it's doing something from where it shouldn't be doing it?!
You haven't shown how your Photos collection is being populated, but I assume it's as simple as viewModel.Photos = entity.Photos. If that's correct (or something similar), then you're just assigning the lazy-loaded entity collection to your view model.
There are several ways to tackle this, but they're all essentially the same: you need to trigger the loading of your collection before you populate your view model. The easiest way to do it is to just stick a .ToArray() or equivalent onto the collection you're assigning; that'll force a fetch.
You are right. It is related to Lazy loading. Try to load Photos eagerly. And check their relations. Maybe they have some with eager loading, you don't need, or you are trying to use associated entity in your view.
Grails offers the ability to automatically create and bind domain objects to a hasMany List, as described in the grails user guide.
So, for example, if my domain object "Author" has a List of many "Book" objects, I could create and bind these using the following markup (from the user guide):
<g:textField name="books[0].title" value="the Stand" />
<g:textField name="books[1].title" value="the Shining" />
<g:textField name="books[2].title" value="Red Madder" />
In this case, if any of the books specified don't already exist, Grails will create them and set their titles appropriately. If there are already books in the specified indices, their titles will be updated and they will be saved. My question is: is there some easy way to tell Grails to remove one of those books from the 'books' association on data bind?
The most obvious way to do this would be to omit the form element that corresponds to the domain instance you want to delete; unfortunately, this does not work, as per the user guide:
Then Grails will automatically create
a new instance for you at the defined
position. If you "skipped" a few
elements in the middle ... Then Grails
will automatically create instances in
between.
I realize that a specific solution could be engineered as part of a command object, or as part of a particular controller- however, the need for this functionality appears repeatedly throughout my application, across multiple domain objects and for associations of many different types of objects. A general solution, therefore, would be ideal. Does anyone know if there is something like this included in Grails?
removeFrom*
Opposite of the addTo method in that it removes instances from an association.
Examples
def author = Author.findByName("Stephen King")
def book = author.books.find { it.title = 'The Stand' }
author.removeFromBooks(book)
Just ran into this issue myself. It's easy to solve. Grails uses java.util.Set to represent lists. You can just use the clear() method to wipe the data, and then add in the ones you want.
//clear all documents
bidRequest.documents.clear()
//add the selected ones back
params.documentId.each() {
def Document document = Document.get(it)
bidRequest.documents.add(document)
log.debug("in associateDocuments: added " + document)
};
//try to save the changes
if (!bidRequest.save(flush: true)) {
return error()
} else {
flash.message = "Successfully associated documents"
}
I bet you can do the same thing by using the "remove()" method in the case that you don't want to "clear()" all the data.
For a good explanation of deleting a collection of child objects with GORM have a look at the Deleting Children section of this blog post - GORM gotchas part 2
It's recommended reading, as are parts 1 and 3 of the series.
I am just starting to learn Grails myself and saw your question as an interesting research exercise for me. I do not think you can use the conventional data binding mechanism - as it fills in the blanks using some kind of Lazy map behind the scenes. So for you to achieve your goal your "save" method (or is it a function?) is unlikely to contain anything like:
def Book = new Book(params)
You need a mechanism to modify your controller's "save" method.
After some research, I understand you can modify your scaffolding template which is responsible for generating your controller code or runtime methods. You can get a copy of all the templates used by Grails by running "grails install-templates" and the template file you would need to modify is called "Controller.groovy".
So in theory, you could modify the "save" method for your whole application this way.
Great! You would think that all you need to do now is modify your save method in the template so that it iterates through the object entries (e.g. books) in the params map, saving and deleting as you go.
However, I think your required solution could still be quite problematic to achieve. My instinct tells me that there are many reasons why the mechanism you suggest is a bad idea.
For one reason, off the top of my head, imagine you had a paginated list of books. Could that mean your "save" could delete the entire database table except the currently visible page? Okay, let us say you manage to work out how many items are displayed on each page, what if the list was sorted so it was no longer in numerical order - what do you delete now?
Maybe multiple submit buttons in your form would be a better approach (e.g. save changes, add, delete). I have not tried this kind of thing in Grails but understand actionSubmit should help you achieve multiple submit buttons. I certainly used to do this kind of thing in Struts!
HTH
I'm just running into this same issue.
My application's domain is quite simple: it has Stub objects which have a hasMany relationship with Header objects. Since the Header objects have no life of their own, they're entirely managed by the Stub controller and views.
The domain class definitions:
class Stub {
List headers = new ArrayList();
static hasMany = [headers:Header]
static mapping = {headers lazy: false}
}
class Header {
String value
static belongsTo = Stub
}
I've tried the "clear and bind" method but the end result is that the "cleared" objects are left over in the database and grails will just create new instances for the ones that were not removed from the relationship. It does seem to work from an user's perspective, but it will leave lots of garbage objects in the database.
The code in the controller's update() method is:
stubInstance.headers.clear()
stubInstance.properties = params
An example: while editing the -many side of this relationship I have (for a given Stub with id=1):
<g:textField name="headers[0].value" value="zero" id=1 />
<g:textField name="headers[1].value" value="one" id=2 />
<g:textField name="headers[2].value" value="two" id=3 />
in the database there are 3 Header instances:
id=1;value="zero"
id=2;value="one"
id=3;value"two"
after removing header "one" and saving the Stub object the database will have headers:
id=1;value="zero"
id=2;value="one"
id=3;value"two"
id=4;value="zero"
id=5;value="two"
and the Stub object will now have an association with Headers with id=4 and id=5...
Furthermore, without the clearing of the list, if an index is not present in the submitted request.headers list, on data binding grails will keep the existing object at that location unchanged.
The solution that occurs to me is to bind the data, then check the Stub's headers for elements that are not present in the submitted list and remove them.
This looks like a pretty simple scenario, isn't there any built-in functionality to address it?
It's a bit overkill to have to write your own synchronization logic for maintaining relationships, especially when the quirks that make it non-trivial are caused by grails itself.
What about deletion, shouldn't the clear()'ed elements be gone from the database? Am I missing something in the relationship or domain object definitions?
class Stub {
List headers = new ArrayList();
static hasMany = [headers:Header]
static mapping = {
headers lazy: false
**headers cascade: "all-delete-orphan"**
}
}
class Header {
String value
static belongsTo = Stub
}
I have added the cascade property on the owning side of relationship and Now if you try to save the stub, it will take care of removing deleted items from the collection and delete them from the DataBase.
What I'm trying to do is rather basic, but I might have my facts mixed up. I have a details page that has a custom class as it's Model. The custom class uses 2 custom objects with yet another custom object a property of one of the 2. The details page outputs a fair amount of information, but allows the user to post a comment. When the user clicks the post button, the page gets posted to a Details action that looks something like this:
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Details(VideoDetailModel vidAndComment) { ....}
The only fields on the form that is posted are CommentText and VideoId. Here is what the VideoDetailModel looks like.
public class VideoDetailModel
{
public VideoDetailModel()
{
Video = new VideoDTO();
Comment = new CommentDTO();
}
public VideoDetailModel(VideoDTO vid)
{
Video = vid;
Comment = new CommentDTO();
}
public VideoDTO Video { get; set; }
public CommentDTO Comment { get; set; }
}
VideoDTO has a few properties, but the ones I need are VideoId. CommentDTO's pertinent properties include CommentText (which is posting correctly) and a UserDTO object that contains a userId property. Everything other than the CommentText value is not being posted. I also have the following line on the ascx page, but the model value never gets posted to the controller.
Html.Hidden("Model.Video.VideoId", Model.Video.VideoId);
I'm really not sure what I'm missing here. I suppose if I added more form fields for the properties I need, they would get posted, but I only need 1 form entry field for the CommentText. If I could get the same Model objects value that were sent to the page to post with the page, that would help.
I'll be happy to make any clarifications needed here. I'm just at loss as to what's going on.
UPDATE
Okay, it looks like the solution is rather simple. I think using the RenderPartial in the middle of a form is problematic somehow to how the form gets written in html. I can't really put my finger on why things went bonkers, but if I do my RenderPartials before my form and then begin my form with the text entry field and the hidden VideoId, the default ModelBinder works just fine. I was beginning the form, writing the hidden VideoId, rendering several partial views, create my CommentText field, and then closed the form out. The CommentText field would get bound just fine. The hidden VideoId would not. Maybe I missed a rule somewhere about using RenderPartial.
For completeness, the partial view I was rendering took a Comment object and just wrote out it's CommentText data. Several of these objects would exist for a single Video object. All of this data was in a custom type and passed into the View (the main view) as it's Model. This partial view did not have a form and did not have any data entry fields.
I'd need to see more of your view page code to really give a thorough answer here but for the one snippet you posted:
Html.Hidden("Model.Video.VideoId", Model.Video.VideoId);
Should really be:
Html.Hidden("Video.VideoId", Model.Video.VideoId);
or
Html.Hidden("vidAndComment.Video.VideoId", Model.Video.VideoId);
Either way will work but I tend to prefer the first if your controller action only takes a single parameter. The default model binder will be (in your example) looking for a method parameter named "Model" or failing that will look for a property "Model" on your VideoDetailsModel class. Since neither of those exist, it can't bind "Model.Video.VideoId" to anything.
Is there any Model Binding Security implemented in your mvc site? To explain what I mean, take a look at this page and read the section near the end titled "Model Binding Security". Note that this can be within your code OR in your global.asax file.