How to display ipywidgets.Dropdown without a value selected - jupyter-notebook

No question anymore. The problem is older ipywidgets version behaviour that looks to be fixed in version 7.
The ipywidgets.Dropdown on its own picks up the first value out of the options list.I would like to display the widget without a value selected.The first value in the list is a pointless default that still needs to be reflected down the workflow path. I read a discussion where a developer went as far as adding empty string item into the list. That fixes the dropdown look (to some extent though as the placeholder attribute is still ignored) but adds a silly selectable empty item to the dropdown list. Adding dummy "None" item to the list is not much better solution.Setting value to None results in the "Invalid selection" exception.I do not understand why the ipywidgets.Dropdown does not follow approach of the simpler widgets where empty value is allowed and placeholder text is dispalyed to prompt the user to select something.Is there a way to make the widget selection not required? Some attribute setting I am not aware of? If that is impossible then what is the simplest possible workaround?

You can just set the dropdown value to None:
import ipywidgets as widgets
d = widgets.Dropdown(options=['hello', 'world'], value=None)
d

in 'ipywidgets' version 7.2.1 you will need to disable user changes to be able to display the widget by setting it to False like this:
d = widgets.Dropdown(options=['hello', 'world'], value=None, disabled=False)

Related

How to introduce additional fields with default values in AEM Touch UI dialogs?

Situation:
We have an AEM 6.4 Touch UI dialog and a number of existing component instances that were created through this dialog.
Now we want to add an additional boolean property (checkbox) to the dialog.
The default value of the new property should be true / checked.
Expected Result:
When an editor opens the updated dialog for an existing component, I would expect that the dialog shows the new checkbox checked since this is the default and the JCR contains no value for existing components.
Actual Result:
The dialog shows the checkbox unchecked for an existing component that has no value for this property in the JCR.
Surprisingly, the dialog shows the checkbox checked for a freshly created component!
Any ideas? Thanks.
Snippet of the checkbox inside the .content.xml file below.
<newProperty
jcr:primaryType="nt:unstructured"
sling:resourceType="granite/ui/components/coral/foundation/form/checkbox"
checked="{Boolean}true"
name="./newProperty"
text="The recently added new property"
uncheckedValue="{Boolean}false"
value="{Boolean}true"
/>
It certainly will require a JS validation, since the absence of the value is falsy for the dialog.
Your example should always work, no need for extra js or properties. When you say there is no existing 'value' for this property, do you mean this property is not there or it is empty? Because an empty property would still have a value, in this case an empty string, resulting in it being read as false and the checkbox being empty. A new componenty does not have this property, resulting in the default being shown. If this does not work as designed, could you extend your example by adding all current properties of the component?
#John Goofy - you just need to add below property
'ignoreData={Boolean}true'
then, your node becomes
<newProperty
jcr:primaryType="nt:unstructured"
sling:resourceType="granite/ui/components/coral/foundation/form/checkbox"
checked="{Boolean}true"
name="./newProperty"
text="The recently added new property"
uncheckedValue="{Boolean}false"
value="{Boolean}true"
ignoreData="{Boolean}true"
/>
please let me know, if it doesn't work for you.

Google Appmaker: Update form based on selected dropdown option

I have an AppMaker app that has a from based off of one address table/datasource. I can get a form with next/prev buttons, but replaced the key field (name) with a dropdown list of all names (a user can start typing names to jump there, with the dropdown showing).
My hope is that when a user selects from the dropdown, the entire form updates and the next/prev buttons work properly as well (there too many records to page thru with next/prev only). I don't have to have next/prev functionality if it complicates things too much.
Currently the dropdown is working, but I cannot get the index for the next/prev buttons set or the rest of the form to reflect the selected dropdown record.
I've tried to set the "onValueEdit" event to something like this...
var selected = widget.value;
var idx = widget.options.indexOf(selected);
console.log("Selected: "+selected+", index = "+idx+"\n");
if(idx < 0) { //...this error is never hit
console.log("Index error - setting to zero!\n");
idx = 0;
}
widget.datasource.loadPage(idx); //...update form?
Two observations via console logging:
The "idx" var is never set to the selected dropdown index reliably, and is
often "0" (tho no error msg ever shows), so the "indexOf()" function
isn't working as expected.
The "selected" var (name) is always correct.
If I call widget.datasource.loadPage(...) with a fixed value (say 5) it has no effect on what is shows in the form either (previous loaded data remains) - obviously not the way to do it :v/
Can you steer a noob in the right direction?
If you are using default App Maker form, then you can see that so-called pager, doesn't actually paginate. It triggers prevItem/nextItem datasource methods, in other words it navigates through datasource items, not pages. Here is a quote from App Maker docs:
nextItem: Selects the next item. For Query Datasources, if the current item is the last item on the page, then this loads the next page and selects the first item on the newly loaded page.
So, if you already have all your items loaded(you set query page size for your datasource to 0), then you need just to change selected item within datasource:
// onValueEdit dropdown event
// assuming, that form and dropdown share same datasource
widget.datasource.selectKey(newValue._key);
If you really have lots of items and it is not feasible to load all of them in one call... then it will be all another story...
UPDATE:
It's important that Options and Value are set as shown in the image below!
However, I had trouble setting them that way (read: wasted hours!) until I wiped them both completely using More options in the binding picklist, and tried again (I had even tried on a brand new app!). I was being forced to choose ..projections.. and then a final field before the OK button would be available.
Not sure if AppMaker is buggy here or there is something simple I'm not understanding!
None of the coding in my original question is required.
Once set this way, binding just works as you would expect it!!
All other fields are set as #datasource.item. and are bound to whatever item is chosen. No Events settings are necessary for the dropdown either, as I thought they might be.
I deleted this page and started again, and replaced the default business name data field with a drop down, I set the dropdown as:
Options: #datasources.Addresses.items
Value: #datasources.Addresses.item
It works fine?! Not sure what happend in my original page!
UPDATE:
So it seems you need to delete both the Value and Options and then re-enter these. The OK will light up when you do.
Also, my original take on App Maker was to build the UI and attach data. That was my first mistake. You build the data then have App Maker build edit/add pages for you.

How to control cursor (carat) position in TextInput in Flex 4.5

I need to handle diagraphs and then convert them on the fly to the proper unicode representation. For example when the user types in:
Sx
My app needs to replace it with:
Ŝ
Now, I've been able to do the replacement no problem. The issue though is that once I've done the replacement, the cursor goes to the beginning of the textbox rather than the end. As I'm trying to update the user's text on the fly, this obvious doesn't work.
How can I get it so that once I replace the text in the TextInput box, the cursor is on the right hand side rather than the left?
Found a solution.
All you have to do is instead of updating the whole text, wipe the current content and then use:
textInput.appendText()
Hopefully this will help someone else :)
The setSelection method is how you set the cursor
textInput.setSelection(textInput.text.length, textInput.text.length);
You can get the current beginning of the selection with TextInput.selectionAnchorPosition and the end of the selection with TextInput.selectionAnchorPosition
Take a look at this SO Question: How do you programmatically move the caret of a Flex TextArea to the end?
If you are using a textArea then this will work (from the selected answer):
textArea.selectionBeginIndex = textArea.length;
textArea.selectionEndIndex = textArea.length;
For the people coming here for the solution for the Spark textInput, this is the way:
textInput.selectRange(textInput.text.length, textInput.text.length);

Textfield value empty when I fill it with javascript

I am using modalpopup to enter some value in a textfield. After the value is selected in the modalpopup view, the modalpopup is closed and the value takes the appropriate value. Even if the value is displayed in the textfield, the textfield1.text returns an empty string. When I see the source code (html), I see that even the textfield isn't displaying anything; it hasn't really had this value input, because the appropriate html input field hasn't got a value yet.
This is the code I use to fill this textfield:
function CloseRequestModal(s)
{
document.getElementById('<%=txtRequest.ClientID%>').value = s;
var mpu = $find('<%=ModalPopupExtender3.ClientID%>');
mpu.hide();
}
Please help.
I would need to see source HTML cause it looks like you have template language mixed into your javascript but perhaps instead of "textfield1.text" you use "textfield1.value"?
Additionally, you would need to view "generated" source (with a browser plugin) or inspect the node with web inspector on safari/chrome or firebug on firefox in order to see the change that you made with javascript.
i fixed this problem in an alternate way.
even if the value is there (in the textfield), none of the events is fired, to let know the browser / compilator that the value really exists.
so i decided, despite editing the value of the textfield, i store this value in the session too. in this case, the value is displayed for user needed in the interface, and on the other hand i use the value that i stored in the session.

ASP.NET 3.5 - Making a field readonly/unmodifiable without "disabling" it

I have a web application with a form that has disabled fields in it. It allows a "Save As" function which basically means the settings can be copied into a new configuration (without being modified) and in the new configuration they can be changed to something else. The problem I am running into with this is that since the fields are disabled, they are not getting posted through and do not appear in the context object on the server side.
When I removed the logic to disable the fields, that part works fine. So the remaining problem is, how to "disable" the fields (not allow any change of the data in any of the entry fields) without really "disabling" them (so that the data gets posted through when saving)?
I was originally looking for a way to do this in CSS but not sure if it exists. The best solution is of course, the simplest one. Thanks in advance!
(Note: by 'disabled' I mean "The textboxes display but none of the text inside of them can be modified at all". It does not matter to me whether the cursor appears when you click inside it, though if I had a preference it would be no cursor...)
http://www.w3schools.com/TAGS/att_input_readonly.asp
readonly attribute is what you want.
i would suggest that instead of using the non-updateable field values from the page's inputs, you retrieve the original object from the DB and copy them from there. It's pretty trivial using something like Firebug to modify the contents of the page whose form will be posted back to modify the values, even if they are marked as readonly. Since you really want the values from the original, I would simply reget the object and copy them. Then you don't need to worry about whether the original (and non-updateable) properties get posted back at all.

Resources