Schematron Validation¶

Last Updated: May 2026 | Version: 1.10.0

Note (Phase 10c): The standalone Schematron editor tab has been retired. Schematron editing and validation — rule check, templates, tester, visual builder, documentation, and CSV/JSON export of results — now live in the Unified Shell's Validation activity panel. Open a .sch file and use the Validation panel's Schematron tools. The capabilities below are unchanged; they are reached through the shell rather than a dedicated sidebar tab.

Schematron lets you create custom validation rules that go beyond what XSD schemas can check. It's perfect for validating business rules and data relationships.

Overview¶

While XSD schemas check the structure of your XML (which elements can appear where), Schematron checks the content and relationships:

XSD Checks	Schematron Checks
Element names	Data values
Element order	Field relationships
Required fields	Business rules
Data types	Conditional requirements

Example Rules¶

"If status is 'approved', an approval date must be present"
"The total must equal the sum of all line items"
"Each ID must be unique in the document"

Button	Shortcut	Description
New	-	Create new Schematron file
Open	-	Open existing Schematron file
Save	Ctrl+S	Save current file
Save As	Ctrl+Shift+S	Save with new name
Save All	-	Save the current file (shown for toolbar consistency across editors)
Add Rule	Ctrl+R	Add a new rule template
Add Favorite	Ctrl+D	Add to favorites
Favorites	Ctrl+Shift+D	Toggle favorites panel
Help	F1	Show help

Code Editor¶

The Code tab provides a full-featured Schematron editor:

Button	Description
Load Schematron	Open an existing file
New File	Create empty Schematron
Save / Save As / Save All	Save current file (Save All mirrors Save for this single-document editor)
New Rule	Insert rule template
New Pattern	Insert pattern template
Format	Format/prettify the XML
Validate	Check Schematron syntax
Test Rules	Test against XML files

The sidebar provides helpful tools:

Quick Help¶

Shows Schematron basics: - <pattern> - Groups related rules together - <rule> - Defines context and conditions - <assert> - Tests a condition (must be true) - <report> - Reports a finding (when condition is true)

Common XPath expressions for Schematron rules.

Document Structure¶

Shows the structure of your current Schematron schema - patterns, rules, and assertions.

Rule Templates¶

Pre-built rule templates you can insert: - Required field check - Unique value check - Conditional requirement - Value comparison - Cross-reference validation

XPath Tester¶

Test XPath expressions against sample XML: 1. Enter an XPath expression 2. Click Test 3. See the result

Schematron Tools in the Unified Shell¶

Updated June 2026 - Added Check Rules and Documentation to the Schematron tools.

When you work with a Schematron file in the Unified Shell, the Validation panel offers a set of Schematron tools:

Tool	What It Does
Rule Templates	Insert ready-made Schematron rule patterns
Tester	Run the rules against an XML file
Rule Builder	Build rules visually
Check Rules	Inspect the Schematron file itself for problems
Documentation	Generate documentation for the Schematron file

Check Rules¶

Check Rules runs an error detector over your Schematron file and shows the issues it finds in a categorised table, so you can fix mistakes in the rules before relying on them. Issues are grouped into categories:

Category	Examples
XML syntax	Malformed XML, unclosed tags
Structural	Missing or misplaced patterns, rules, or assertions
XPath	Invalid XPath expressions in contexts or tests
Semantic	Rules that can never match, or contradictory conditions
Best practice	Style and maintainability suggestions

Documentation¶

Documentation opens the Schematron documentation generator, which produces readable documentation describing the patterns, rules, and assertions in your Schematron file.

Creating Schematron Rules¶

Basic Structure¶

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://purl.oclc.org/dsdl/schematron">
    <title>My Validation Rules</title>

    <pattern name="Invoice Validation">
        <rule context="invoice">
            <assert test="@date">
                Every invoice must have a date attribute.
            </assert>
            <assert test="customer">
                Every invoice must have a customer element.
            </assert>
        </rule>
    </pattern>
</schema>

Common Rule Patterns¶

Required Field¶

<rule context="order">
    <assert test="orderNumber">
        Order number is required.
    </assert>
</rule>

Conditional Requirement¶

<rule context="order">
    <assert test="not(@status='shipped') or shipDate">
        Shipped orders must have a ship date.
    </assert>
</rule>

Value Comparison¶

<rule context="order">
    <assert test="endDate >= startDate">
        End date must be after start date.
    </assert>
</rule>

Sum Validation¶

<rule context="invoice">
    <assert test="sum(item/price) = total">
        Total must equal sum of item prices.
    </assert>
</rule>

Unique Values¶

<rule context="items">
    <assert test="count(item) = count(distinct-values(item/@id))">
        All item IDs must be unique.
    </assert>
</rule>

Cross-Reference¶

<rule context="orderLine">
    <assert test="@productId = //product/@id">
        Product ID must reference an existing product.
    </assert>
</rule>

Testing Rules¶

Test Against XML Files¶

Click Test Rules in the toolbar
Select one or more XML files
View validation results

Integration with XML Editor¶

Use Schematron validation directly in the XML Editor:

Open an XML file in the XML Editor
In the validation panel, select your Schematron file
Errors are highlighted in the editor
Click errors to jump to the problem location

Favorites Integration¶

Save frequently used Schematron files for quick access:

Add Favorite (Ctrl+D) - Save current file to favorites
Favorites (Ctrl+Shift+D) - Show/hide the favorites panel

XPath Reference¶

Common XPath expressions for Schematron rules:

Expression	Description
`.`	Current node
`@attribute`	Attribute of current node
`child::element`	Child element
`parent::element`	Parent element
`//element`	Any element in document
`count(element)`	Count elements
`string-length(.)`	Length of text content
`contains(., 'text')`	Text contains substring
`starts-with(., 'text')`	Text starts with
`normalize-space(.)`	Normalized whitespace
`sum(element)`	Sum of numeric values
`distinct-values(element)`	Unique values

Supported Formats¶

Format	Support
ISO Schematron (.sch)	Full support
XSLT-based Schematron	Full support

Keyboard Shortcuts¶

Shortcut	Action
Ctrl+S	Save file
Ctrl+Shift+S	Save As
Ctrl+R	Add new rule
Ctrl+D	Add to favorites
Ctrl+Shift+D	Toggle favorites
F1	Help

Tips¶

Start simple - Begin with basic rules and add complexity
Test both ways - Test with valid and invalid sample files
Clear messages - Write helpful error messages for users
Use patterns - Group related rules into patterns
XPath Tester - Use the sidebar to test expressions

Troubleshooting¶

Problem	Solution
Rule not firing	Check the context XPath matches elements
False positives	Review your test condition logic
Namespace issues	Add namespace declarations to schema
Performance slow	Optimize complex XPath expressions

Previous	Home	Next
IntelliSense	Home	Schema Support

Schematron Validation¶

Overview¶

Example Rules¶

Code Editor¶

Sidebar Panels¶

Quick Help¶

Document Structure¶

Rule Templates¶

XPath Tester¶

Schematron Tools in the Unified Shell¶

Check Rules¶

Documentation¶

Creating Schematron Rules¶

Basic Structure¶

Common Rule Patterns¶

Required Field¶

Conditional Requirement¶

Value Comparison¶

Sum Validation¶

Unique Values¶

Cross-Reference¶

Testing Rules¶

Test Against XML Files¶

Integration with XML Editor¶

Favorites Integration¶

XPath Reference¶

Supported Formats¶

Keyboard Shortcuts¶

Tips¶

Troubleshooting¶

Navigation¶

Schematron Validation¶

Overview¶

Example Rules¶

Toolbar¶

Code Editor¶

Editor Toolbar¶

Sidebar Panels¶

Quick Help¶

Document Structure¶

Rule Templates¶

XPath Tester¶

Schematron Tools in the Unified Shell¶

Check Rules¶

Documentation¶

Creating Schematron Rules¶

Basic Structure¶

Common Rule Patterns¶

Required Field¶

Conditional Requirement¶

Value Comparison¶

Sum Validation¶

Unique Values¶

Cross-Reference¶

Testing Rules¶

Test Against XML Files¶

Integration with XML Editor¶

Favorites Integration¶

XPath Reference¶

Supported Formats¶

Keyboard Shortcuts¶

Tips¶

Troubleshooting¶

Navigation¶