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<title>Adding simple types</title>
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<h1 class="topictitle1">Adding simple types</h1>
<div><p>Simple types are used to created derived datatypes. They provide
a set of constraints on the value space (that is, a set of values) and the
lexical space (that is, a set of valid literals) of a datatype.</p>
<div class="section"><p>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 a simple type.</p>
<p>The following
instructions were written for the Resource perspective, but they will also
work in many other perspectives.</p>
<p>To add a simple type, follow these
steps:</p>
</div>
<ol><li class="stepexpand"><span>Open your XML schema in the XML schema editor.</span></li>
<li class="stepexpand"><span>In the Outline view, select your schema.</span> The entire
schema and its contents should be displayed in the Graph view.</li>
<li class="stepexpand"><span>In the Graph view, right-click in the <strong>Types</strong> section and
click <b> <span class="uicontrol">Add Simple Type</span></b>.</span></li>
<li class="stepexpand"><span>In the Properties view, click the <span class="uicontrol">General</span> tab,
and type a new name for the simple type in the <b> <span class="uicontrol">Name</span></b> field.</span></li>
<li class="stepexpand"><span>You can select the following options from the <b> <span class="uicontrol">Variety</span></b> list:</span><ul><li>
	<b><span class="uicontrol">atomic</span></b>. Atomic types are all the simple types
built into the XML schema language.</li>
<li><b><span class="uicontrol">list</span></b>. List types are comprised of sequences
of atomic types. They have values that are comprised of finite-length sequences
of atomic values. </li>
<li><b><span class="uicontrol">union</span></b>. 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.</li>
</ul>
</li>
<li class="stepexpand"><span>If you selected <span class="uicontrol">atomic</span> from the 
<b> <span class="uicontrol">Variety</span></b> drop
down list, click the <b> <span class="uicontrol">More</span></b> <img src="../images/More.gif" alt="This graphic is the More button" /> button next to the 
<b> <span class="uicontrol">Base
type</span></b> field to specify a base type for the simple type.</span> The Set 
Type dialog lists all built-in and user-defined types currently available. You 
can change the <b> <span class="uicontrol">Scope</span></b> of the list by selecting one
of the following options:<ul><li><b><span class="uicontrol">Workspace</span></b>. Lists all of the types available in
your workspace. </li>
<li><b><span class="uicontrol">Enclosing Project</span></b>. Lists all of the types available
in the project that contains your file. </li>
<li>(Default)<b> <span class="uicontrol">Current Resource</span>.</b> List all of the types
available in your current file.</li>
</ul>
	</li>
<li class="stepexpand"><span>If you selected <span class="uicontrol">list</span> from the 
<b> <span class="uicontrol">Variety</span></b> drop
down list, click the <b> <span class="uicontrol">More</span></b> <img src="../images/More.gif" alt="This graphic is the More button" /> button next to the 
<b> <span class="uicontrol">Item
type</span> </b>field to specify a item type for the simple type.</span> The
Set Type dialog lists all built-in and user-defined types currently available.
You can change the <b> <span class="uicontrol">Scope</span></b> of the list by selecting one
of the following options:<ul><li><b><span class="uicontrol">Workspace</span></b>. Lists all of the types available in
your workspace. </li>
<li><b><span class="uicontrol">Enclosing Project</span></b>. Lists all of the types available
in the project that contains your file. </li>
<li>(Default) <b> <span class="uicontrol">Current Resource</span></b>. List all of the types
available in your current file.</li>
</ul>
	</li>
<li class="stepexpand"><span>If you selected <span class="uicontrol">union</span> from the 
<b> <span class="uicontrol">Variety</span></b> drop
down list, click the <b> <span class="uicontrol">More</span></b> <img src="../images/More.gif" alt="This graphic is the More button" /> button next to the 
<b> <span class="uicontrol">Member
types</span> </b>field to specify the member types for the simple type.</span> You can select to add both 
<b> <span class="uicontrol">Built-in simple types</span></b> and <b> <span class="uicontrol">User-defined
simple types</span></b> to the member types value list. </li>
<li class="stepexpand"><span>Click the <b> <span class="uicontrol">Enumerations</span></b> tab.</span> Enumerations
help you to define a set of valid values for simple types. They 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:<ol type="a"><li class="substepexpand"><span>To add one enumeration at a time, click the 
	<b> <span class="uicontrol">Add</span></b> button
and specify a value for the enumeration.</span></li>
<li class="substepexpand"><span>To add several enumerations at one time, follow these steps:</span> <ol type="i"><li>Click the 
	<b> <span class="uicontrol">Add...</span></b> button.</li>
<li>Enter the value of each enumeration. Each value must be separated by the <b> <span class="uicontrol">Delimiter
character</span></b>. For example: <samp class="codeph">First, Second</samp> will create
two enumerations, one with the value "First" and one with the value "Second".</li>
<li>Select the <b> <span class="uicontrol">Preserve leading and trailing whitespace</span></b> 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 <samp class="codeph">First, Second</samp> will
show up as "First" and " Second" (there is a space before Second) because
you put a space before "Second" when entered the value.</li>
<li>Click <b> <span class="uicontrol">OK</span></b>. Your enumerations will be created and
appear in the Properties view.</li>
</ol>
</li>
</ol>
</li>
<li class="skipspace"><span>Click the <b> <span class="uicontrol">Documentation</span></b> tab if you want
to provide any information about this simple type.</span> The <span class="uicontrol">Documentation</span> page
is used for human readable material, such as a description, and the <span class="uicontrol">App
Info</span> page can be used to provide information for applications.</li>
<li class="skipspace"><span>Click the <b> <span class="uicontrol">Advanced</span></b> tab.</span> The options
available from this page will vary depending on what option you selected in
the <b> <span class="uicontrol">Variety</span></b> field, and the <b> <span class="uicontrol">Base type</span>,</b>
<b> <span class="uicontrol">Item
type</span>,</b> or <b> <span class="uicontrol">Member types</span></b> field on the <span class="uicontrol">General</span> page.</li>
<li class="skipspace"><span>If applicable to the type, the <b> <span class="uicontrol">Facets</span></b> 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.</span><ol type="a"><li><span>To change a facet's value, click its name in the 
	<b> <span class="uicontrol">Name</span></b> column,
then click its value (or the empty cell that will contain its value) in the <b> <span class="uicontrol">Value</span></b> column
and type or select a new value.</span></li>
<li><span> To change whether a facet's value is fixed or not, click its
name in the <b>Name</b> column, then click the appropriate cell in the <b>Fixed</b> column,
and change the value to true or false.</span></li>
</ol>
</li>
<li class="stepexpand"><span>If applicable to the type, a Pattern page will be available. Click
the <b> <span class="uicontrol">Patterns</span></b> tab to switch to it.</span> 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.</li>
</ol>
	<p><b class="reltaskshd">Related tasks</b><br />
	<a href="taddreg.html">Adding pattern facets to simple types</a></p>
	</div>
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