XPath Editor
Overview
The XPath Editor is a full-featured code editor for writing XPath expressions. Every target field also has an inline expression input for quick edits, but the XPath Editor is the right tool when:
- The expression is too long or complex to read and write comfortably in the inline input
- You want to browse the function catalog — the left panel lists all available XPath 3.1 functions organised by category, so you don’t need to memorise them; drag one into the editor to insert it with its parameter placeholders
- You want auto-completion and hover help — as you type, the editor suggests matching functions and shows their full signature and description on hover
Opening the XPath Editor
To edit or create complex XPath expressions, click the fx button on any target field that has a mapping. This opens the XPath Editor where you can build your expression.
Building XPath Expressions
The XPath Editor interface provides two main areas: a palette on the left with fields and functions, and an expression editor on the right.
Adding Fields
You can add source fields to your expression by:
- Typing directly — Enter field paths manually using XPath syntax
- Drag and drop — Drag fields from the Fields tab and drop them into the editor
Using XPath Functions
The XPath Editor ships a full XSLT 3.0 / XPath 3.1 function catalog organized into 15 categories:
| Category | Examples |
|---|---|
| String | concat(), string-join(), upper-case(), lower-case(), normalize-space(), replace() |
| Substring Matching | starts-with(), ends-with(), contains(), substring(), substring-before(), substring-after() |
| Pattern Matching | matches(), tokenize(), analyze-string() |
| Numeric | sum(), avg(), min(), max(), round(), floor(), ceiling(), format-number() |
| Date and Time | current-date(), current-time(), current-dateTime(), format-date(), format-time() |
| Boolean | boolean(), not(), true(), false() |
| QName | QName(), local-name(), namespace-uri(), prefix-from-QName() |
| Node | name(), node-name(), root(), path(), has-children(), innermost(), outermost() |
| Sequence | count(), empty(), exists(), distinct-values(), index-of(), reverse(), subsequence() |
| Context | position(), last(), current(), current-group(), current-grouping-key() |
| Math | math:pi(), math:exp(), math:log(), math:sin(), math:cos(), math:pow(), math:sqrt() |
| Map | map:merge(), map:get(), map:put(), map:keys(), map:contains(), map:remove() |
| Array | array:size(), array:get(), array:put(), array:append(), array:join(), array:flatten() |
| Higher-Order | fn:apply(), fn:filter(), fn:fold-left(), fn:fold-right(), fn:for-each(), fn:for-each-pair() |
| XSLT | key(), element-available(), function-available(), current-output-uri(), unparsed-text() |
To browse and use functions:
- Switch to the Functions tab in the left palette
The tab has a “Filter functions…” input at the top — type part of a function name to narrow the list across all categories instantly.
You can also collapse function categories by clicking the chevron next to the category header.
- Drag the function you need and drop it into the editor
- Fill in the function parameters with field references or literal values
Saving Your Expression
Once you’ve built your XPath expression, click the Close button to apply it to the mapping.
The mapping will now appear in the tree view with your custom XPath expression.
Start with simple expressions and test them before adding complexity. You can always reopen the XPath Editor to refine your expression.
Auto-Completion
The expression editor supports IntelliSense-style auto-completion for XPath functions. As you type a function name, a suggestion list appears automatically. You can also trigger it explicitly by pressing Ctrl+Space.
Each suggestion shows:
- The function name as the completion label
- The full function signature (parameters and return type) as detail text
- A description of what the function does
Selecting a suggestion inserts the function name followed by an argument placeholder so the cursor lands inside the parentheses, ready for you to type or drag in a field reference.
Auto-completion works for all 15 function categories in the XPath 3.1 catalog. It also completes XPath keywords such as return, satisfies, instance of, and treat as.
Hover Help
Hovering the cursor over any function name in the expression editor shows a tooltip with:
- The complete function signature (parameter names, types, and return type)
- A description of the function’s behaviour
This is useful when you remember a function name but need a quick reminder of the argument order or expected types without leaving the editor.
Next Steps
- Variables — define
xsl:variablevalues that can be referenced in XPath expressions - Field Context Menu — advanced schema-level operations such as type overrides and abstract element substitution