Graphical User Interface

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Revision as of 06:24, 22 September 2011 by CG (talk | contribs) (→‎Visualizations)
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The BaseX homepage gives you a visual impression of the graphical user interface (GUI) of BaseX, and the introductory video presents some of the interactive features that the BaseX GUI provides. This small tutorial demonstrates how easy it is to perform simple XPath queries.

Startup

First of all, please launch a GUI instance of BaseX. Depending on your operating system, double click on the BaseX GUI start icon or run the basexgui script. Follow this link for more information (or check out the additional command-line options).

Create Database

Select DatabaseNew and browse to the factbook.xml document. This XML file contains statistical information on the worlds' countries. It is included in the official releases of BaseX, and it can also be downloaded here.

Next, choose the OK button, and BaseX will create a database that you can visually explore.

Visualizations

The BaseX GUI offers various visualizations, which help you to explore your XML data instances from different perspectives:

Text

Displays query results and other textual output. Query results can be saved in a file.
 

Map

This visualization represents all data in a TreeMap. All nodes of the XML document are represented as rectangles, filling the complete area. You can choose one of the following layout algorithms in the Menu OptionsMap Layout: Split, Strip, Squarified, Slice&Dice and Binary Layout.

Tree

This visualization displays all XML nodes in a top down tree with edges and nodes. You can change some settings of the Tree in the Menu OptionsTree Options.
 

Folder

This visualization displays all nodes in a usual folder view.
File:Scatterplot.jpg
Scatterplot View

Plot

This visualization displays all nodes in a scatterplot. There are drop down menus to configure the allocation of the Y- and X-axis.
 
File:TableView.jpg
The Table View

Table

This visualization displays all nodes in a table with rows and columns.
File:ExplorerView.jpg
Explorer View

Explorer

With this visualization you can explore the contents of your database via drop-down menus, search fields and some sliders.
 
Info View

Info

This visualization gives details on the execution of database commands and XQuery expressions.

Querying

Apart from the basic search facilities, BaseX offers far more sophisticated processing options to query your documents. Below are some examples you might give a try. This guide is far from being a comprehensive XQuery reference, but might point you in the right direction.

To execute the following queries, enter them in the XQuery Panel and hit the PLAY button.

XPath provides an easy facility to query your documents in a navigational manner. It is the basic tool of all node-related operations that you encounter when using XQuery. We will start with a trivial example and extend it to our needs.

Example: Find Countries

//country

tells BaseX to look for all country elements in the document. The query is introduced by two slashes //, which trigger the traversal of all document nodes. XPath knows several location steps that determine which nodes to consider next for evaluation.

As an example, //country is equivalent to /descendant::country.

Example: Find Cities in Switzerland

The following query uses a predicate [...] to filter all country nodes which have a name child, the string value of which is "Switzerland":

//country[name = "Switzerland"]

To return all cities of the resulting element node, the query can be extended by a trailing //city path:

//country[name = "Switzerland"]//city

What's Next?

For more information on BaseX, XQuery and XPath, we invite you to...