The XPath/XQuery Builder View

The XPath/XQuery Builder view allows you to compose complex XPath and XQuery expressions and execute them over the currently edited XML document. For XPath 2.0 / 3.0, or XQuery expressions, you are able to use the doc() function to specify the source file over which the expressions are executed. When you connect to a database, the expressions are executed over that database. If you are using the XPath/XQuery Builder view and the current file is an XSLT document, Oxygen XML Editor executes the expressions over the XML document in the associated scenario.

To open the XPath/XQuery Builder view, go to Window > Show View > XPath/XQuery Builder.

The upper part of the view contains the following actions:

A drop-down menu that allows you to select the type of the expression you want to execute. You can choose between:
- XPath 1.0 (Xerces-driven)
- XPath 2.0, XPath 2.0SA, XPath 3.0, XPath 3.0SA, XQuery 1.0, XQuery 3.0, Saxon-HE XQuery, Saxon-PE XQuery, or Saxon-EE XQuery (all of them are Saxon-driven)
- Custom connection to XML databases that can execute XQuery expressions
  Note: The results returned by XPath 2.0 SA and XPath 3.0 SA have a location limited to the line number of the start element (there are no column information and no end specified).
  
  Note: Oxygen XML Editor uses Saxon to execute XPath 3.0 expressions. Since Saxon implements a part of the 3.0 functions, when using a function that is not implemented, Oxygen XML Editor returns a compilation error.
Execute XPath button - Press this button to start the execution of the XPath or XQuery expression you are editing. The result of the execution is displayed in the Results view in a separate tab
Favorites button - Allows you to save certain expressions that you can later reuse. To add an expression as favorite, press the star button and enter a name under which the expression is saved. The star turns yellow to confirm that the expression was saved. Expand the drop-down menu next to the star button to see all your favorites. Oxygen XML Editor automatically groups favorites in folders named after the method of execution
History drop-down menu - Keeps a list of the last 15 executed XPath or XQuery expressions. Use the Clear history action from the bottom of the list to remove them
Settings drop-down menu - Contains the following three options:
- Update on caret move - When enabled and you navigate through a document, the XPath expression corresponding to the XML node at the current cursor position is displayed.
- Evaluate as you type - When you select this option, the XPath expression you are composing is evaluated in real time.
  Note: The Evaluate as you type option and the automatic validation are disabled when you edit huge documents or when the scope is other than Current file.
- Options - Opens the Preferences page of the currently selected processing engine.
XPath scope menu - Oxygen XML Editor allows you to define a scope on which the XPath operation will be executed. You can choose where the XPath expression will be executed:
- Current file - Current selected file only.
- Project - All the files in the project.
- Selected project resources - The files selected in the project.
- All opened files - All files opened in the application.
- Current DITA Map hierarchy - All resources referenced in the currently selected DITA map, opened in the DITA Maps Manager view.
- Opened archive - Files open in the Archive Browser view.
- Working sets - The selected working sets.
At the bottom of the scope menu there are available the following scope configuration actions:
- Configure XPath working sets - Allows you to configure and manage collections of files and folders, encapsulated in logical containers called working sets.
- XPath file filter - You can filter the files from the selected scope on which the XPath expression will be executed. By default the XPath expression will be executed only on XML files, but you can also define a set of patterns that will filter out files from the current scope. If you select the Include archive option, the XPath expression will be also executed on the files in any archive (including EPUB and DocX) found at the current scope.

Figure: The XPath/XQuery Builder View

While you edit an XPath or XQuery expression, Oxygen XML Editor assists you with the following features:

Content Completion Assistant - It offers context-dependent proposals and takes into account the cursor position in the document you are editing. The set of functions proposed by the Content Completion Assistant also depends on the engine version. Select the engine version from the drop-down menu available in the toolbar.
Syntax Highlight - Allows you to identify the components of an expression. To customize the colors of the components of the expression, open the Preferences dialog box and go to Editor > Syntax Highlight.
Automatic validation of the expression as you type.
Note: When you type invalid syntax a red serrated line underlines the invalid fragments.
Function signature and documentation balloon, when the cursor is located inside a function.

The usual edit actions Cut, Copy, Paste, Select All, Undo, Redo are available in the contextual menu of the top editable part of the view.