oxy:allows-child-element() Function
      
      The oxy:allows-child-element() function allows you to check whether or not
            an element that matches the arguments of the function is valid as a child of the element
            at
            the current cursor position, according to the associated schema. It is evaluated at
            the cursor
            position and has the following signature:
         
oxy:allows-child-element($childName, ($attributeName, $defaultAttributeValue,
                  $contains?)?)
The following parameters are supported:
- childName
- The name of the element that you want to check if it is valid in the current context.
                  Its value is a string that supports the following forms:
                  - The child element with the specified local name that belongs to the default
                        namespace.oxy:allows-child-element("para")The above example verifies if the para element (of the default namespace) is allowed in the current context.
- The child element with the local name specified by any
                        namespace.oxy:allows-child-element("*:para")The above example verifies if the para element (of any namespace) is allowed in the current context.
- A prefix-qualified name of an element.
                        oxy:allows-child-element("prefix:para")The prefix is resolved in the context of the element where the cursor is located. The function matches on the element with the para local name from the previous resolved namespace. If the prefix is not resolved to a namespace, the function returns a value offalse.
- A specified namespace-URI-qualified name of an
                        element.oxy:allows-child-element("{namespaceURI}para")The namespaceURIis the namespace of the element. The above example verifies if the para element (of the specified namespace) is allowed in the current context.
- Any
                        element.oxy:allows-child-element("*")The above function verifies if any element is allowed in the current context.NoteA common use case ofoxy:allows-child-element("*")is in combination with theattributeNameparameter.
 
- The child element with the specified local name that belongs to the default
                        namespace.
- attributeName
- The attribute of an element that you want to check if it is valid in the current
                  context. Its value is a string that supports the following forms:
                  - The attribute with the specified name from no
                        namespace.oxy:allows-child-element("*", "class", " topic/topic ")The above example verifies if an element with theclassattribute and the default value of this attribute (that contains thetopic/topicstring) is allowed in the current context.
- The attribute with the local name specified by any
                        namespace.oxy:allows-child-element("*", "*:localname", " topic/topic ")
- A qualified name of an
                        attribute.oxy:allows-child-element("*", "prefix:localname", " topic/topic ")The prefix is resolved in the context of the element where the cursor is located. If the prefix is not resolved to a namespace, the function returns a value offalse.
 
- The attribute with the specified name from no
                        namespace.
- defaultAttributeValue
- A string that represents the default value of the attribute. Depending on the value of the next parameter, the default value of the attribute must either contain this value or be equal with it.
- contains
- An optional boolean. The default value is true. For thetruevalue, the default value of the attribute must contain thedefaultAttributeValueparameter. If the value isfalse, the two values must be the same.
