I have a situation where I need to update a control referenced in a masterpage from a control that is referenced from the content page. Below is hierarhcy:
MainMasterPage
BreadCrumbUserControl(a user control) - has a public string property
ContentPage(uses MainMasterPage)
DataUserControl
I want to be able to update the exposed property of BreadCrumbUserControl from DataUserControl on pageLoad.
I was able to update the BreadCrumbUserControl property just fine from the ContentPage. When i try to do the same DataUserControl's pageLoad method, the update is ignored because of page life cycle.
How can I go about achieving this? I can think of doing something on the clientside using hiddenField and such, but wanted to see if there is a better solution.
Thanks for your help.
It is possible to do what you are asking but I wouldn't. I would raise an event from the "DataUserControl" and handle it in the page. Then the page class can update the master page's control value. This will reduce coupling of your controls and the page they are used on.
Related
I followed this link http://www.wintellect.com/devcenter/jprosise/handling-the-back-button-in-windows-10-uwp-apps and "successfully" make my button work. I mean I can make my backbutton work between pages. However, if I navigate to a control which is inside this page and will cover the whole screen, then it would not allow me to back to the page. I will stuck in that control.
I'm wondering how to solve this problem. Currently I can think two possible ways (0) Override OnBackRequested() inside the control's code behind or viewmodel? (1) Override OnHardwareButtonsBackPressed() inside the control's code behind or viewmodel?. I don't know if these are correct way to do it or there is some better way to do it. Another reason for me to override is that I need to make some changes to the page navigation behavior.
As you have guessed, you simply need to hide the control again when the back button is pressed or back is requested in some other way. I would listen for the BackRequested event (not the HardwareButtons.BackPressed event) in the page's code-behind, and in the handling method you can check to see if the control is currently shown. The reason I recommend the BackRequested event is because it is universal, while HardwareButtons.BackPressed only works on a phone. Anyway, if the control is visible, then hide it, and set the Handled property of the event arguments to true. If the control is already hidden, don't do anything special to handle the event (because in that case you will want the navigation system to handle it by navigating to the previous page, if there is one). There are many aspects to navigation in Windows 10 -- please see these pages on Navigation and the SystemNavigationManager.
On a page I have some fields that I want to be "readonly" (in my meaning they can't be accessed but they will store values, read earlier question in this matter if issues...).
I use a client JS setting these attributes on page load:
$(".readonly").attr('readonly', true);
If I have a partial update on any of these fields the attribute is lost and the field is accessible.
What is the best practice to overcome this and make it work?
Every partial refresh has a oncomplete method bound to it. What you could do is add code to the oncomplete method so the item is being set readonly again. Another, better, approach would be not to change the attribute clientside but to have hidden fields which are used to store the data.
When you have an event bound to for instance an Link control you can change the oncomplete code by clicking in your source pane on the event tag. When you browse the events section in the properties pane you will see the onComplete, onError, onStart properties. You can add your own clientside script in these properties.
Before trying to overcome the "problem" You shoud try to understand what exactly partial refresh do and where the state of application is kept.
Unfortunately partial refresh is replacing current html content (or rather part of it) with a newly created one and only form fields that has backing controls will keep state.
I suggest You should try setting readonly property on controls which You would like to make readonly (if there is some logic here You can always use ssjs).
Optionally You can try to preserve the state on the client side by using csjs global variables but this is rather hard to manage.
And one more thing - try to use the technology to solve the problem(xpages) and try not to hack Your way through with use of stuff that You accidentally know (jquery).
I would agree with jjtbsomhorst on using onComplete event. But another alternative could be setting the readonly property via code like this:
var textField:com.ibm.xsp.component.xp.XspInputText = getComponent("inputText1");
var readOnlyAttr:com.ibm.xsp.complex.Attr = new com.ibm.xsp.complex.Attr("readonly", "readonly");
var list:java.util.ArrayList = new java.util.ArrayList();
list.add(readOnlyAttr);
textField.setAttrs(list);
You could call this on the afterPageLoad event of the XPage. But I really don't know whether this would be the best way to about!
I am using a file download control and I would like to set the value of the "allowDelete" property dynamically depending on whether the document is in edit or read mode. However, this
property is computed onload of the page. I tried calling the function "setAllowDelete(boolean)" on the onclick event of a button or the "beforeRenderResponse" event of a custom control and a partial or full update to change the value of the property, but it didn't change.
Do you know if there is a way to do this?
Thanks a lot in advance!
I have encountered the same problem. There are two options to workaround it.
1) To use two controls, one with deletion enabled, the other with deletion disabled, and use rendered properties according to edit state (or user role).
2) Render download controls by your own, as data table or repeat. However, this solution has its own problems, too.
Have you tried just calculating the property like this?
<xp:fileDownload .... >
<xp:this.allowDelete><![CDATA[${javascript:
return document.isEditable()}]]>
</xp:this.allowDelete>
</xp:fileDownload>
my question is about view controllers, delegates and all that in general. I feel perfectly comfortable with UIView, UIViewController, Delegates and Sources, like UITableView does for instance. It all makes sense.
Now I have implemented my first real custom view. No XIBs involved. It is an autocomplete address picker very much like in the Mail application. It creates those blue buttons whenever a recipient is added and has all the keyboard support like the original.
It subclasses UIView. There is no controller, no delegate, no source. I wonder if I should have either one of those? Or all, to make it a clean implementation.
I just cannot put my finger on the sense a view controller would make in my case. My custom view acts much like a control and a UIButton doesn't have a controller either.
What would it control in my view's case?
Some of my thoughts:
For the source: currently the view has a property "PossibleAutocompleteRecipients" which contains the addresses it autocompletes. I guess this would be a candidate for a "source" implementation. But is that really worth it? I would rather pass the controller to the view and put the property into the controller.
The selected recipients can be retrieved using a "SelectedRecipients" property. But views should not store values, I learned. Where would that go? Into the controller?
What about all the properties like "AllowSelectionFromAddressBook"? Again, if I compare with UIButton, these properties are similar to the button's "Secure" property. So they are allowed to be in the view.
The delegate could have methods like "WillAddRecipient", "WillRemoveRecipient" and so on and the user could return TRUE/FALSE to prevent the action from happening. Correct?
Should I maybe inherit from UIControl in the first place and not from UIView?
And last but not least: my custom view rotates perfectly if the device is rotated. Why don't all views? Why do some need a controller which implements ShouldAutoRotateToDeviceOrientation()?
Does it make sense what I wrote above? In the end I will provide the source on my website because it took me some time to implement it and I would like to share it as I have not found a similar implementaion of the Mail-App-like autocomplete control in MonoTouch.
I just want to learn and understand as much as possible and include it in the source.
René
I can answer part of your question.
I just cannot put my finger on the
sense a view controller would make in
my case
The ViewController is responsible for handling the View's state transitions (load, appear, rotate, etc) These transitions are used mainly when you use a navigation component (UINavigationViewController, UITabBarController). These components needs to received a ViewController that will handles the view's transitions.
For exemple, when you push a ViewController on a UINavigationViewController, it will cause the ViewDidLoad, ViewWillAppear, ViewDidAppear. It will also cause the ViewWillDisappear, ViewDidDisappear of the current ViewController.
So, if your application has only one portrait view, you don't need a ViewController. You can add your custom view as a subview of the main window.
I want to able to create reusable user controls within my web app and i'm wondering on how to go about doing so.
Should a user controls properties be
visible to a form that's using it?
What's the best way to go about
loading the controls on the user
control from the form thats using
it? Should there be a public method
within the control that allows you
to load it from an external form or should the user
control be loaded in the page load
event
Is it okay to nest user controls within user controls?
etc...
Thanks for any advice
1) You only need to make properties visible if any page needs to read or modify information on your control. I personally like to keep my user controls as self contained as possible, and keep this to a minimum.
2) I would just rely on the built in page life cycle to render your control, but it is important to note when each of your control's events fire in relation to your pages. You may find that there are times that you need something on your control to render before something on your page does. In this case you will need to rely on the page_init in your control more than the page_load of your control.
3) You technically can nest user controls, but things will get tricky if you need to start reading and writing information (as in your first question) from any of the nested controls. Also, the page life cycle of the nested controls gets even more important. I would avoid this if you can.