I'm not talking about boolean attributes, attributes like class if you don't want to add an empty class attribute if there's no CSS class.
html`<span class=${hasClass ? 'my-class' : ''}></span>`
There is an ifDefined directive that does what you want. If the value is undefined the attribute won't be rendered.
import {ifDefined} from 'lit-html/directives/if-defined';
html`<span class=${ifDefined(hasClass ? 'my-class' : undefined)}></span>`
Related
I have a simple problem. Inside a modelForm, in my Meta class, inside widgets={} i have specified:
'video' : forms.FileField(allow_empty_file=True)
however django complains that 'FileField' object has no attribute 'attrs'. What could be the issue
A FileField [Django-doc] is a form field, not a widget*. The default widget of a FileField is a ClearableFileInput [Django-doc].
You can thus construct a (model)form with:
class MyForm(forms.Form):
video = forms.FileField(allow_empty_file=True)
# …
I am trying to extract an Attribute from an ExampleSet in a RapidMiner 'Execute script' like this:
ExampleSet exSet = input[0];
Attributes attrs = exSet.getAttributes();
Attribute attr = attrs.getAttribute("h_area");
but then I get an error and it says that attrs is not a Attributes but a SimpleAttributes object.
This works:
Attribute[] attrs2 = exSet.createRegularAttributeArray();
Attribute attr2 = attrs2.getAt(1);
What is the correct way to get an Attribute from an ExampleSet?
From these docs, it looks like the getAttributes() call will return an object implementing the Attributes abstract class, which SimpleAttributes is, so it looks pretty fair at this stage. However, the getAttribute() method doesn't look like it's defined in either object. I can't test this here and now, but have you tried the following:
ExampleSet exSet = input[0];
Attributes attrs = exSet.getAttributes();
Attribute attr = attrs.get("h_area");
I'm trying to display XmlElement's attributes in Xceed PropertyGrid. For that purpose I defined custom wrapper class. It wraps XmlElement, iterates over XmlAttributes and creates custom PropertyDescriptor for each XmlAttribute. All "virtual" properties' type is String. All works fine.
Now I want to have drop-down list of possible attribute values for every attribute that has restricted set of values. In Xceed's PropertyGrid, there is ItemsSourceAttribute for that. But it has to be applied as follows:
ItemsSourceAttribute(typeof(MyCustomItemsSource))
And here is the problem - I can not provide proper argument for MyCustomItemsSource constructor. What can I do about this?
It seems that there is another possibility - to define a TypeConverter, override GetStandardValues, and supply this converter to "virtual" property. But PropertyGrid just ignores this attribute.
How this simple task can be done with Xceed PropertyGrid?
Solved. I implemented custom editor
public class AttributeValuesEditor: Xceed.Wpf.Toolkit.PropertyGrid.Editors.ComboBoxEditor
{
protected override IEnumerable CreateItemsSource(PropertyItem propertyItem)
{
var property = propertyItem.PropertyDescriptor as XmlAttributePropertyDescriptor;
Debug.Assert(property!=null);
return property.GetCompletionValues();
}
}
Here, the context is passed into method in the form of PropertyItem. Now it is possible to differentiate between different attributes and return appropriate items.
Given the following example xsd snippet:
< xs:attribute name="SEGMENT" default="" use="optional" type="xs:string"/ >
when xjc generates the class containing the SEGMENT bean attribute, the following getter is auto-generated:
public String getSEGMENT() {
if (segment == null) {
return "";
} else {
return segment;
}
}
My question is how do you get it do the same for xs:element objects? In other words, given the following xsd snippet:
< xs:element name="NAME" default="" type="xs:string"/ >
I want to know if I can get xjc to generate the following:
public String getNAME() {
if (name == null) {
return "";
} else {
return name;
}
}
How can this be done?
JAXB doesn't generate the same code for an element with default value as it does for an attribute with default value because the XML schema differentiates between element and attribute defaults:
Default values of both attributes and elements are declared using the default attribute, although this attribute has a slightly different consequence in each case. When an attribute is declared with a default value, the value of the attribute is whatever value appears as the attribute's value in an instance document; if the attribute does not appear in the instance document, the schema processor provides the attribute with a value equal to that of the default attribute. Note that default values for attributes only make sense if the attributes themselves are optional, and so it is an error to specify both a default value and anything other than a value of optional for use.
The schema processor treats defaulted elements slightly differently. When an element is declared with a default value, the value of the element is whatever value appears as the element's content in the instance document; if the element appears without any content, the schema processor provides the element with a value equal to that of the default attribute. However, if the element does not appear in the instance document, the schema processor does not provide the element at all. In summary, the differences between element and attribute defaults can be stated as: Default attribute values apply when attributes are missing, and default element values apply when elements are empty.
You can always count on the default value for a missing attribute (from here the special getter) but there is a catch with a missing element value.
Nonetheless, when you unmarshall an instance, the unmarshaller knows how to handle the default value. See here for details:
Element default values and marshalling
Element default values and unmarshalling
XJC won't add the getter code or initialize the fields with the default value, so if you need the "null safe check" you can either add it yourself manually after the code is generated by XJC or try to use some plugin to do it automatically:
JAXB 2 Default Value Plugin
CXF XJC Default Value Plugin
I'm trying to put an autocomplete that fetches suggestions as a list of Entry<String, Integer>
<p:autoComplete completeMethod="#{suggester.suggestTopics}"
var="x1" itemLabel="#{x1.key}" itemValue="#{x1.value.toString()}"
value="#{topicController.selected}" />
Manged bean code is as follows:
private int selected;
public int getSelected() {
return selected;
}
public void setSelected(int selected) {
this.selected= selected;
}
But this fails saying the Integer class doesn't have method/property named key. If I remove the value attribute from autocomplete then it starts working properly. But when I put value attribute it starts expecting that the object inside var should be of the same type as that inside value attribute. I believe/expect it should be that the object inside itemValue should be of the same type as that inside value attribute.
I want to use POJOs for suggestions but pass just the entity Id to the value
Using :
Primefaces 3.1
JSF 2.1.6
I believe/expect it should be that the object inside itemValue should
be of the same type as that inside value attribute.
Yes this makes sense, and it is the same in the primefaces showcase:
<p:autoComplete value="#{autoCompleteBean.selectedPlayer1}"
id="basicPojo"
completeMethod="#{autoCompleteBean.completePlayer}"
var="p" itemLabel="#{p.name}" itemValue="#{p}"
converter="player" forceSelection="true"/>
As you see is var="p" and itemValue="#{p} where p is an instance of Player. And selectedPlayer1 is also an instance of Player.
I don't know if it works with a Map since the Primefaces example is called "Pojo support" and the suggestions should be a List of elements of the same type as in the value attribute.
I think you want to use the Simple auto complete , but instead you looked at the wrong example on the showcase of the Pojo Support
x1 refers to the int selected - while it expect to be referred to a POJO (with key and value properties.) , that's why you get the message
Integer class doesn't have method/property named key
Or simple use the Simple auto complete
As commented to Matt you dont need to rebuild Player(Pojo) from Db. You can set simply id property of Player(Pojo) and in action method may be utilize this id to fetch it from DB.
In your case in convertor you might do
Entry<String, Integer> e = new Entry<String, Integer>();
e.setId(value) // where value is passed in to convertor in method getAsObject.....
This value will be set to private Entry<String, Integer> selected
I have used Pojo autocomplete but not tried with generic classes.
Hope this helps.
I know the question is outdated but I've had the same problem.
The point is that you have to assign var to p (var="p"). I think it's terribly unobvious (documentation doesnot mention it has to be that way) 'cause I thought I can assign any var name I want.