I'm trying to create a dynamic survey application in Prime Faces. I have a list of Question Objects that each contains a list of AnswerChoices. These are given to the f:selectItems value attribute. This is fine. The question object also contains a List of selectedValues which is given to the relevant selectOne/many component.
Because I'm looking to be generic, there will be questions that have multiple selected values and also some that have only one selected value. I wanted to be able to point the selectOne and selectMany components to the List of strings within the relevant Question object that represents the selectedValues.
This works ok for the selectMany component, but not for the selectOne component which needs to be pointed at a singular object rather than a list. Is there an easy way around this that I'm missing - as I'd like to only have one object representing the selectedValues if possible
You can use brace notation to bind the value to a list/array item at a specific index. The below example binds the value to the 1st item of the list/array.
<h:selectOneMenu value="#{bean.selectedAnswers[0]}" />
There's however a caveat: you need to prepare the list/array with the single item yourself during bean's (post)construction. JSF/EL won't do that in case of a <h:selectOneMenu>.
E.g.
#PostConstruct
public void init() {
selectedAnswers = new ArrayList<Answer>();
selectedAnswers.add(null);
}
It doesn't harm to reuse this preinitializated property for UISelectMany components by the way.
Related
We have a Set<String> that we are printing to the page in Thymeleaf:
<h5>Unique Students names</h5>
<ol>
<div th:each="uniqueName: ${course.uniqueStudentsNames}">
<li th:text="${uniqueName}"></li>
</div>
</ol>
Since it is a Set<String> there is no order of the items in the set.
We like to convert the non-ordered Set<String> to an ordred List<String> so we will be able to print it by ABC. Since it is a UI issue, we don't like the backend to change its data structure.
An option we thought about is to create such a list in the Model:
model.addAttribute("course", course);
model.addAttribute("orderedList", /* convert Set to ordred List */);
But this seems very strange that the Model needs to handle such a UI issue.
Is there a way to do it in Thymeleaf?
Instantiate it as a TreeSet (you are probably using hashset?) and you have a set with the ordering behaviour you want. Set<String> (Set<anything> really) guarantees there won't be repeated items, but it does not imply anything about the order/unorder.
On the other side, thymeleaf, as a template engine, won't do such things as adding ordering behaviour to a collection that does not implement it. The most it will do is allow you to access methods of the collection; in the case of set: set utility methods.
If you no matter what want to use a non ordered set, you'd have to use something like javascript to manipulate the items on the client to order them.
Use the Thymeleaf utility method to convert the object to a List:
${#lists.toList(object)}.
Then perform a utility operation to sort as needed from there, optionally using your own Comparator.
The current Thymeleaf source code shows that the toList() method will check if the target object is an instance of Iterable. In your case, Set implements the interface.
To reference the external link:
if (target instanceof Iterable<?>) {
final List<Object> elements = new ArrayList<Object>(10);
for (final Object element : (Iterable<?>)target) {
elements.add(element);
}
return elements;
}
I have some ExtJs component.
I set itemId for it, but id is autogenerated.
Now Ext.getCmp('autogenerated-id') returns my component.
But Ext.ComponentQuery.query('#autogenerated-id') returns an empty array.
But:
Ext.ComponentQuery.query('[id=assets-information-form-1918]') again returns my component. :)
I use ExtJs 6.5.3 classic.
It seems like itemId config property hides autogenerated id from Ext.ComponentQuery, so they become mutually exclusive.
I don't need other means for search or advice to set id for the component, to write letter to Sencha support or to write post on their forum.
I need:
Means to force my Ext.ComponentQuery.query('#autogenerated-id') to
find the Component for which getId() returns 'autogenerated-id'.
If it is not possible by design, I need a link to some documentation
describing this behavior, a link to some bug report, or a filename and line number in ExtJs sources + a little snippet copy/paste from there.
From the documentation
Summary Provides searching of Components within Ext.ComponentManager
(globally) or a specific Ext.container.Container on the document with
a similar syntax to a CSS selector. Returns Array of matching
Components, or empty Array.
Ext.ComonpentQuery.query('#itemId') returns and array. Your cold above is using the auto-generated id of the component. The # indicates to query based on the component itemId and not the component id.
Try
Ext.ComponentQuery.query('assets-information-form-1918');
which will return an array, as noted in the documentation.
Ext.getCmp()
This is shorthand reference to Ext.ComponentManager#get. Looks up an
existing Ext.Component by id
Therefore it returns the component object.
Ext.ComponentQuery.query('#itemId')[0] would return the first object in the array.
Ext.ComponentQuery is the Sencha preferred method because it is more powerful when used as it does return an array so you an also query items by xtype and other attributes.
I have an question about binding:
I have an array of objects of my custom class: Array. Every object can be updated (change his properties value) in bg.
Also I have separated Controller, which take and store one object from list as variable and can update it (object still the same, so in list it will be updated too)
Is there any way to bind all object.property -> UILabels on Controller in way, when property changes automatically call label update?
Of course, there are multiple ways how to do it, but from your description I would use some kind of subject (because u said there will be changes in background so you will probably need hot observable )....For example Variable or PublishSubject. So you can crate
let myArrayStream: Variable<[MyObject]> = Variable([])
you can pass this variable as dependency to wherever you want, on one side you can subscribe to it, on the other side you can update it's value.
I've an array of objects containing title and salary which is used in typeahead directive.
I display department name and get entire object as value.
If none of the options match, I want user entered string to be converted to object still. Is there any way to update that?
This answer is pretty late, but I would just use ng-blur (to trap the end of the users input) along with a variable bound to typeahead-no-results. Then test if the variable is true in the method bound to ng-blur, and, if so, make an object out of the String supplied by the user and push it to your data source. Simple example found here.
In my jsp page I have a form (in struts2) in which I try to assign the size of the ArrayList data to the Vector testVector using hidden tag after submitting the form, but I still get the size of testVector equal to 0.
<s:hidden name="testVector.size" value="%{data.size}" />
I have created setters and getters for data and testVector in my Action class.
private Vector<String> testVector = new Vector<String>();
private ArrayList<String> data = new ArrayList<String>();
private String testName; // a field for testing the form.
// getters and setters of testVector and data
I supposed that this should work because Vector has a public setter setSize(int size).For the other field "testName" it was well submitted.. So am I have a problem in syntax?
Thank you a lot.
You should not be using a Vector. Be aware that OGNL does not work the same from a requests as it does when rendering a JSP for security reasons, it is simply too powerful. You should just set bean properties, collections, arrays and built in types from the request (type converters ignored).
From the request in this case it thinks are are trying to put values into the vector. I think it will create a new string put it into the Vector and then try to set the size of string (which will not work because that method does not exist).
To confirm this I tried to do what you are saying and the log states:
WARNING: Error setting expression 'testVector.size' with value '[Ljava.lang.String;#5c7b2d2f'
ognl.OgnlException: Error converting given String values for Collection. [ognl.NoSuchPropertyException: java.lang.String.size]
If you want this behaviour you will need to create a second method such as setSize() within your action which then goes about modifying the vector size. This I don't think is a very good thing to expose to the outside world, what if someone called your action many times passing in a huge number?