XML Schema indicator

By the indicator, we can control the use of the elements in the document mode.

Indicator

There are seven indicators:

Order indicators:

• All
• Choice
• Sequence

Occurrence indicator:

• maxOccurs
• minOccurs

Group indicator:

• Group name
• attributeGroup name

Order indicator

Order indicators are used to define the order of the elements.

All indicator

<All> indicator in accordance with the provisions of sub-elements can appear in any order, and each child element must appear only once:

Note: When using the <all> indicator, you can put <minOccurs> is set to 0 or 1, but only the <maxOccurs> indicator is set to 1 (later explain <minOccurs> and <maxOccurs>).

Choice Indicator

<Choice> indicator provides for a sub-element occur or may occur another child element (or the other):

Sequence Indicator

<Sequence> child element must be specified in a specific order:

Occurrence indicator

Occurrence indicators are used to define the frequency of an element occur.

Note: For all of the "Order" and "Group" indicator (any, all, choice, sequence , group name and group reference), which maxOccurs and minOccurs defaults are 1.

maxOccurs indicator

<MaxOccurs> indicator can specify the maximum number of times an element can occur:

The above examples show that the child element "child_name" may appear in the least "person" element once (where the default value of minOccurs is 1), appears at most 10 times.

minOccurs indicator

<MinOccurs> indicator may require a minimum number of times an element can occur:

The above examples show that the child element "child_name" there may be a minimum of 0 in "person" element, appears at most 10 times.

Tip: To make the number of occurrences of an element is not limited, please use the maxOccurs = "unbounded" this statement:

A practical example:

Called "Myfamily.xml" XML file:

Above this XML file contains a root element named "persons" of. Inside this root element, we have defined three "person" element. Each "person" element must contain a "full_name" elements, but it may contain up to 5 "child_name" element.

This is the schema file "family.xsd":

Group indicator

Group indicator for several batches of elements related to the definition.

Element Group

Element group defined by the group declared:

You must define a statement within the group all, choice or sequence elements. The following example defines a group named "persongroup", which defines a set of elements that must be present according to a precise order:

After you have defined the group is completed, you can refer to it in another definition of:

Property group

Attribute groups defined by attributeGroup statement:

The following example defines a property group named "personattrgroup" of:

After you have defined a complete set of attributes, you can reference it in another definition, like so: