In the XML schema editor, you can add a simple type to an XML schema.
A simple type cannot have element content and cannot carry attributes. Elements
that contain numbers (and strings, and dates, and so on) but do not contain
any sub-elements are said to have simple types.
The following instructions were written for the Resource
perspective, but they will also work in many other perspectives.
To
add a simple type, follow these steps:
- Open your XML schema in the XML schema editor.
- In the Outline view, select your schema. The entire
schema and its contents should be displayed in the Graph view.
- In the Graph view, right click in the Types section and
click Add Simple Type.
- In the Properties view, click the General tab,
and type a new name for the simple type in the Name field.
- You can select the following options from the Variety drop
down list:
- atomic - atomic types are all the simple types
built into the XML schema language
- list - list types are comprised of sequences
of atomic types. They have values that are comprised of finite-length sequences
of atomic values.
- union - a union type enables an element or
attribute value to be one or more instances of one type drawn from the union
of multiple atomic and list types
- If you selected atomic from the Variety drop
down list, click the More button next to the Base
type field to specify a base type for the simple type. You
can select either a Built-in simple type, or User-defined
simple type to be the base type.
- If you selected list from the Variety drop
down list, click the More button next to the Item
type field to specify a item type for the simple type. You
can select either a Built-in simple type, or User-defined
simple type to be the item type.
- If you selected union from the Variety drop
down list, click the More button next to the Member
types field to specify the member types for the simple type. You can select both Built-in simple type, or User-defined
simple type to add to the member types list.
- Click the Enumerations tab. Enumerations
help you to define a set of valid values for simple types. Enumerations are
the actual values the simple type can take as valid values in the instance
document. You can either add one enumeration or several enumerations at a
time:
- To add one enumeration at a time, click the Add button
and specify a value for the enumeration.
- To add several enumerations at one time, follow these steps:
- Click the Add... button.
- Enter the value of each enumeration. Each value must be separated by the Delimiter
character. For example: First, Second will create
two enumerations, one with the value "First" and one with the value "Second".
- Select the Preserve leading and trailing whitespace check
box if you want any white space around your enumeration values to be preserved.
If, for example, you select this check box, the values of First, Second will
show up as "First" and " Second" (there is a space before Second) because
you put a space before "Second" when entered the value.
- Click OK. Your enumerations will be created and
appear in the Properties view.
- Click the Documentation tab if you want
to provide any information about this simple type. The Documentation page
is used for human readable material, such as a description, and the App
Info page can be used to provide information for applications.
- Click the Advanced tab. The options
available from this page will vary depending on what option you selected in
the Variety field, and the Base type, Item
type, or Member types field on the General page.
- If applicable to the type, the Facets table
will be populated with constraining facets. A constraining facet is an optional
property that can be applied to a datatype to constrain its value.
- To change a facet's value, click its name in the Name column,
then click its value (or the empty cell that will contain its value) in the Value column
and type or select a new value
- To change whether a facet's value is fixed or not, click its
name in the Name column, then click the appropriate cell in the Fixed column,
and change the value to true or false.
- If applicable to the type, a Pattern page will be
available. Click the Pattern tab to switch to it. A pattern can be used to constrain the value of a type's lexical space
(the set of string literals that represent the values of a type), which indirectly
constrains the value space. For more information on adding a pattern to a
simple type, refer to the related tasks.
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