SPARQL Blockly is an app for visualising and constructing SPARQL queries.
It supports SPARQL 1.1 Query (try), Update (try) and SPARQL* (try).
See the Source code on Github.
Text written into the textarea at the top is parsed by SPARQL.js. Valid queries are visualised into blocks on the canvas below:
The textarea will turn green for a valid and red for an invalid query.
Parsing errors for invalid queries are displayed below the textarea.
Query blocks can be constructed by right-clicking the canvas and the blocks to add appropriate clauses from the context menus:
Only appropriate blocks can be added, so the context menus enforce the SPARQL grammar.
Queries can also be constructed by dragging blocks from the toolbox, dropping them unto the canvas and attaching them to existing blocks:
Only appropriate blocks can be attached.
Blocks can be collapsed from the context menus:
Collapsed blocks show the SPARQL they represent.
The app takes URL-encoded SPARQL queries from the URL fragment, so queries and their visual representations can be shared.