I'm trying to build a fairly complex form which as a couple of cascading selects - i.e. the user selects a value in one combo and the other combo is populated according to their first selection.
I've followed a tutorial on how to handle the cascading but the problem I have is that I now have nested forms (the code in the tutorial uses forms inside partial views to POST to a controller action to load the 2nd combo). I have my main form on which I want to collect the input values but also the nexted forms for the cascading select boxes. The problem I have is that the cascading selection doesn't post to the correct controller action, but instead posts to my main (outer) form's action.
I understand this is the correct behaviour for a browser (as nested forms apparently aren't supported) but what's the correct way to implement this?
The correct way is to only have one form. Then use AJAX to populate the cascading drop down list. The are 100s of examples online how to do this with JSON
use this to have multiple submit buttons on one form which each have different controller actions to post to:
http://iwayneo.blogspot.co.uk/2013/10/aspnet-mvc-action-selector-with-list.html
as for cascading stuff - i would focus on populating these without Ajax 1st - then you can worry about adding this sort of flare - if it doesn't work without JS anyway you're in a bad place.
I would have the 1st dropdown populated when you initially load the form and have a "next" button to populate the next dropdown in the cascade. this submit can use the method above to post to an action which then populates the second data set based on the selection of the 1st dropdown.
make sense?
Then how you ajax that after the point is up to you but you'll have a very solid foundation to build up stuff like that as you will have it working in the minimal tech scenario.
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I want to enable a pair of cascading dropdown lists within a form in an ASP.NET MVC3 / Razor2 application. Ideally the solution will meet the following goals:
Child list populated simply by changing the selection of the parent list
Both dropdown lists contained within the form as they need to post information on submit
Uses Ajax to avoid whole page round-trip
Uses Ajax Html helper for easy integration
Works even if javascript is not enabled
So, from a user point of view, when an item in the parent dropdown is selected, the contents of the child dropdown is refreshed to display items related to it.
Can anyone please suggest the best way to do this?
EDIT.
No takers ... suggests to me that there may be conflicting requirements in the above list of goals. The closest I got to the above was this article, which met all the goals except that it doesn't work nested within an Html form.
So, I will restate the problem in a different way: how can I make an AJAX call from a dropdown list within an Html form so that I can populated another dropdown list with related items?
Took some time to find a reasonable solution to this, although so far I still don't have a no-jquery fallback. This article shows you how to use AjaxHelper extensions to create your own Ajax-enabled controls. Works a treat, and very reusable.
I am buiding a UI screen for editing the details of an Ecommerce Order. The model for my view (OrderModel) has everything I need (in properties that are also ViewModels), but the UI isn't designed to be able to edit all of it at once.
For example, one part of the UI is for customer data..another for order details, and another for tracking information, each having their own "Save" buttons.
I realize that I could use one giant form and use hidden form fields to populate the non-editable fields, making each "Save" button post all the data, but that smells bad.
I'd like to segment the editable chunks into smaller ViewModels that are posted and validated individually while retaining the strong typing but I'm unsure of how to achieve this in MVC3. Will I need partial views that are called from the primary view?
FYI, I'm using ASP.NET MVC 3 with Razor syntax and client side FluentValidation.
Partial Views are a good solution. You can pass different ViewModels to each partial view. But if only sections of the overall view are updated at a time I would not do a post back on the whole page. Instead I would use Ajax calls using JQuery/Javascript to update the individual information back to the controller. I would also look into something like Knockout.js to handle the data binding on the page.
I have a Form to create a new model object and persist it. That form is displayed in a lightbox or popup.
Some fields are dropdownlist showing related info that lives in another table (other model object related to the main model).
What I need to achieve is without leaving the creation form, create a new item of the related type and update the DropDownList in order to continue filling fields and finaly submit the form.
I have done this in winforms but not really sure which is the best approach in MVC 3:
Trigger another popup with a small form?
Use some kind of editable dropdownlist?
Place a small hidden form right next/after the DDL to allow entering the info to create an item in DDL (and to DB also)?
What do you thing is the best option?
Thanks!
There is no editable dropdown list in HTML. There are some toolkits that simulate it, but in general these are clumbsy and really complex. It's a lot easier to stick with basic controls.
You would proably do best to have a small + sign next to the field, and then popup an editing field that inserts the element into the combobox and sends it to the controller via ajax to add to the database.
An alternative to a second pop up is having a toggle add button. When toggled, then show a small area where you can enter the name. Using ajax, save the name, and then refresh your dropdown. This works well if you only have a few attributes to fill in.
I have one view page in MVC named as ‘Index’. There are 3 main controls in that view page. For better understanding, take below example as reference.
1. One Dropdown ‘Customer’
2. One Dropdown ‘Project’ (that depends on ‘Customer’)
3. List of Task (that depends on ‘Project’).
Currently first user needs to select ‘Customer’. So based on customer ‘Project’ dropdown data will be fetched from post method of Index and bind that ‘Project’ dropdown. After selecting ‘Project’, List of task will be fetch from post method of Index and bind those tasks. So every time page is loaded again.I want to do it by Ajax form submit.
My problem – those 3 controls are in one view page so I want to return page view using Ajax without using Partial View. Is this possible? If yes then how? Or any other solution so that I am able to display data without reload whole page again.
If u can give me example of such scenario then it will be good.
I have a few complex GUI elements (like a custom calendar with many days that can be highlighted) that appear along with standard django form input fields. I want to process the data I/O from these complex forms along with the Django forms.
Previously I would use AJAX requests to process these custom GUI elements on my HTML form after the Django form was saved or rendered, but this leads to a host of problem and customized AJAX coding. What is a good way to handle complex interactions widgets in a Django form?
Not sure if I understand completely, but you could have the value of your UI saved into a hidden element on the form via javascript. This can either be done as they select the values in the UI or when they submit the form. Pseudo-code assuming JQuery using submit() to save before the submit data is sent:
$('#myForm').submit(function(){
// get the value of your UI
var calendarValue = calendarWidget.getValue()
// #calendarData is the hidden field
$('#calendarData').val(calendarValue)
})
This obviously requires JS, but so does using your UI element.
Your question is very vague so I suggest you read the Django documentation on writing a custom field and hopefully that will help you get started. You might also want to investigate writing a custom widget. Unfortunately the documentation is bit lacking on that, but a Google search brings up several useful blog posts, including this one.
You have three options depending on how you output your Django Form subclass to the HTML page.
The first doesn't involve Form at all. Any html form inputs will end up in request.POST, so you can access them there. True, they won't be bound to your Form subclass, so you would have to manually inject the value either using a custom form constructor, or by setting some property on your Form object after instantiating it with request.POST. This is probably the least desirable option, but I mention it in case your use-case really doesn't support anything else.
The second is an option if you manually output the form fields in your HTML (ie: using {{ myform.field }} rather than just {{ myform }}. In this case, make a hidden variable to contain the value of your calendar GUI tool (chances are, your GUI tools already offer/require one). Add this hidden field, with the right name and ID, to the Form subclass itself, making sure it has a hidden django form widget. If necessary, use javascript as Rob suggests to populate the hidden field. When the form is posted, it will get bound to your form subclass as normal because, this time, you have a field on your Form subclass with that name. The machinery for clean() will work as normal.
The third, and best option, is to write a custom django field; Andrew's post has the link. Django fields have the ability to specify js and css requirements, so you can automatically encapsulate these dependencies for any page that uses your calendar widget.