0 — Getting started
Debug XML Tool is a local, offline development environment for editing and step-by-step debugging of XML / XSLT / XSD / DTD transformations.
No network connection is required, neither at startup nor in use. No data leaves your machine.
This chapter takes you from a working folder to a first transformation, then to a first breakpoint. Allow two minutes.
0.1 Open a workspace
On first launch, the application shows its welcome screen: XSLT/XML Debugging IDE, with the prompt « Open a workspace ( 📂 ) or drag and drop a folder here ». The left-hand panel reads No workspace open — open a folder to get started.
A workspace is simply a folder on your disk: the one holding your stylesheets and your XML files.
Two ways to open it:
- Click Open workspace folder (the first folder icon on the toolbar), then choose the folder;
- or drag and drop the folder straight onto the welcome screen.
The left-hand explorer fills up. It shows only the relevant files (.xml, .xsl, .xslt,
.xsd, .dtd, .xspec…), each with an icon of its own type.
The last workspace opened is restored automatically on the next start, along with the size and position of the window.
To close the current workspace, use Close workspace, the neighbouring icon. It is active only while a workspace is open.
0.2 Open a file
Double-click a file in the explorer: it opens in an editor tab, with syntax highlighting and validation as you type.
You can open as many files as you need; each takes its own tab. A tab that has been modified but not saved carries a dot « • » before its name. The dot disappears as soon as you save (Ctrl+S) — or if you undo all your changes.
0.3 Run a first transformation
Take a common case: a main.xsl stylesheet formatting an input.xml catalogue.
- Open your stylesheet (
main.xsl) with a double-click. It becomes the active tab. - Press F5 — or click Run transformation (the ▶ button on the toolbar).
That is all. You had nothing to configure.
Debug XML Tool works out on its own what to run:
- the stylesheet is the one in the active tab;
- the source XML document, if none has been designated, is the first XML file found in the workspace;
- the output file is generated next to the source document.
The console (bottom panel, first tab) records each of these decisions:
[Auto-config] XML source auto-detected: input.xml
[Auto-config] Output auto-generated: input_out_2026-08-02.html
--- Starting transformation ---
XML: C:\...\input.xml
XSLT: C:\...\main.xsl
Output: C:\...\input_out_2026-08-02.html (format: AUTO)
--- Transformation completed in 136 ms ---
The result opens in a new read-only tab. The xsl:message messages from your stylesheet
appear in the console as execution proceeds.
If nothing runs
The diagnosis appears in the status message, to the right of the toolbar — not in the console.
| Status message | Cause | What to do |
|---|---|---|
| Error: configure an XSLT file via ⚙ or open a .xsl in the editor | the active tab is not a stylesheet | open your .xsl, or designate it explicitly (below) |
| Error: no XML file found in workspace | the folder holds no .xml | open a workspace that has one |
| Error: XSLT file not found — … | the designated file has been moved or deleted | designate it again |
Designating the files explicitly
Auto-detection is fine to get going. As soon as your workspace holds several XML documents, designate them yourself: right-click a file in the explorer, then
- Set as XML source on a
.xml; - Set as main XSL on a
.xslor.xslt.
The Transformation settings button (⚙) offers full control: output format (Auto / HTML / Text / XML / PDF), stylesheet parameters, and entry point. See the chapter Transforming & exporting.
0.4 Set a first breakpoint
This is where Debug XML Tool comes into its own.
- In your stylesheet tab, click in the gutter to the left of the line number, opposite an
instruction — an
<xsl:value-of>inside an<xsl:for-each>, for example. A red dot appears. - Press F5.
Execution starts, then stops on your line, which is highlighted in yellow. The status badge on the toolbar switches to PAUSED, and the stepping buttons become active.
You can then inspect the exact state of the transformation:
| Bottom panel | What it shows |
|---|---|
| Variables | the local XSLT variables and the current XML node |
| Call Stack | the chain of templates that led here |
| XPath Evaluator | evaluate any expression in the context of the pause |
| Watch XPath | expressions re-evaluated automatically at every stop |
And step forward:
| Key | Action |
|---|---|
| F8 | Resume — until the next breakpoint |
| F10 | Step Over — next line, without entering the templates called |
| F11 | Step Into — enter the template called |
| Shift+F11 | Step Out — leave the current template |
| Shift+F9 | Stop |
The Debugging chapter details each of these gestures, conditional breakpoints and inspection.
0.5 Where to find what
| Area | Contents |
|---|---|
| Toolbar (top) | workspace, running and stepping, validation, format, comparison, profiler, settings |
| Explorer (left) | the workspace tree; right-clicking there opens most of the actions |
| Editor (centre) | your files in tabs, with a breakpoint gutter |
| Bottom panel | 13 tabs: console, inspection, analysis, search, validation… |
| Right panel | structure of the active file (XML tree, XSD schema, or stylesheet outline) |
The bottom panel tabs are detachable: right-click a tab → Detach to right to place it in the right-hand column, Reattach to bottom to put it back. Only one panel can be detached at a time.
0.6 Setting up the application
The Settings button (the last icon on the toolbar) gives access to:
- Theme — Dark or Light;
- Language — French, English, Spanish, Russian, Chinese;
- Font Size — also adjustable with Ctrl + +, Ctrl + −, Ctrl + 0;
- Word Wrap, Minimap, Highlight Current Line;
- Live validation, Output back-mapping, XML Catalogs…
These preferences are kept from one session to the next.
What next
- Debugging — the heart of the product: breakpoints, stepping, inspection.
- The interface — the five areas of the window, the panels, the settings.
- Editing — completion, formatting, validation, schema association.
- Transforming & exporting — output formats, parameters, reusable scenarios.
- Analysing — profiler, template coverage, output back-mapping.
- Navigating & refactoring — definitions, references, renaming, search and replace across the workspace.
- Validating & comparing — batch validation, XML catalogues, structural comparison, XSpec tests.
- Reference — every shortcut, button, menu and gesture, in tables.