Adding global elements

A global element is an element with a global scope. It is one that has been declared as part of the main schema rather than as part of a content model.

The following instructions were written for the Resource perspective, but they will also work in many other perspectives.

To add a global element, follow these steps:

  1. Open your XML schema in the XML schema editor.
  2. In the Outline view, select your schema. The entire schema and its contents should be displayed in the Graph view.
  3. In the Graph view, right click in the Elements section and click Add Element.
  4. In the Properties view, click the General tab, and type a new name for the global element in the Name field.
  5. Specify its type information by clicking the Browse button and selecting the appropriate type. The Set Type dialog lists all built-in and user-defined types currently available. You can change the Scope of the list by selecting one of the following options:
    • Workspace. Lists all of the types available in your workspace.
    • Enclosing Project. Lists all of the types available in the project that contains your file.
    • (Default) Current Resource. List all of the types available in your current file.
  6. (Optional) Click the Other tab.  In this page, you can specify the following various values for the global element:
    • abstract. Click true if you want the global element to be abstract. When a global element is declared to be abstract, it cannot be used in an instance document. Instead, a member of that global element's substitution group must appear in the instance document.
    • block. This field determines whether the global element may be replaced by an element derived from it.
    • final. This field determines whether this global element may be derived from.
    • fixed/default. Click the Browse button and select the Fixed or Default radio button and specify an appropriate value. If you select Fixed, the global element has a fixed value, which cannot be changed. If you select Default, the element has a default value.
    • form. Use this field to indicate if the appearance of this global element in an instance of the XML schema (that is, an XML file associated with the XML schema) must be qualified by a namespace.
    • nillable. Select true if you do not want the global element to be able to have any child elements, only attributes.
    • substitutionGroup. A substitution group allows elements to be substituted for other elements.
     
  7. Click the Attributes tab. You can use this page to add attributes, attribute references, attributes group references, and any attributes to your global element.
  8. An attribute associates an attribute name with a specific type and value. To add an attribute, right-click in the Attributes page, and click Add Attribute. You can specify the following values for an attribute
    • fixed/default. Click the Browse button and select the Fixed or Default radio button and specify an appropriate value. If you select Fixed, the attribute has a fixed value, which cannot be changed. If you select Default, the attribute has a default value.
    • form. Use this field to indicate if the appearance of this attribute in an instance of the XML schema must be qualified by a namespace.
    • name. Enter the name of the attribute.
    • type. Click the Browse button and select the type of the attribute.
    • use. This field indicates how an attribute may be used in an instance document. If you select optional, the attribute may appear once, but it does not have to. If you select required, the attribute must appear once. If you select prohibited, the attribute must not appear. Note: If you selected the Default radio button, you must select optional in this field, otherwise the default value will not be valid.
  9. An attribute reference provides a reference to a global attribute. To add an attribute reference, right-click in the Attributes page, and click Add Attribute Ref. A declaration that references a global attribute enables the referenced attribute to appear in the instance document in the context of the referencing declaration. The menu option to add an attribute reference only appears if there are global attributes defined elsewhere in the document.
    1. Select the reference, then select the global attribute you want it to reference from the ref drop down list.
  10. An attribute group reference provides a reference to an attribute group. To add an attribute group reference, right-click in the Attributes page, and click Add Attribute Group Ref. A declaration that references an attribute group enables the referenced attribute group to appear in the instance document in the context of the referencing declaration. The menu option to add an attribute group reference only appears if there are attribute groups defined elsewhere in the document.
    1. Select the reference, then select the attribute group you want it to reference from the ref drop down list.
  11. An any element enables element content according to namespaces, and the corresponding any attribute element enables attributes to appear in elements. To add an any attribute, right-click in the Attributes page and click Add Any Attribute. You can specify the following values for an any attribute:
    • For a namespace value, you can select ##any (this allows any well-formed XML from any namespace), ##local (this allows any well-formed XML that is not declared to be in a namespace, ##other (this allows any well-formed XML that is not from the target namespace of the type being defined) or ##targetNamespace (which is shorthand for the target namespace of the type being defined).
    • For a processContents value, you can select skip (the XML processor will not validate the attribute content at all), lax(the XML processor will validate the attribute content as much as it can), or strict (the XML processor will validate all the attribute content).
  12. Click the Documentation tab if you want to provide any information about this global element. 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.
You can add a content model to a global element, which is the representation of any data that may be contained inside the global element. For more information about working with content models, refer to the related tasks.

Related tasks
Adding a content model
Adding an element reference