This QlikView Expressor sample workspace provides an example of a Read operator extension for executing a REST APIs. It demonstrates the following capabilities:
- Make a REST GET Call: Using the Datascript dscurl package to send an HTTP request and reading the resulting HTTP response. See the function named ‘RestGetCall’ in the RestServices Datascript module of the RESTful library.
- Parsing JSON: Using the Datascript json package to parse the result stream. Note that currently only JSON formatted results are supported. See the use of the ‘json.decode’ function in the function named ‘GetAndParseData’ in the RestServices Datascript module of the RESTful library.
- Extended Connections: Using an extended connection artifact type to control the user experience of supplying (and validating) parameters to modify the REST connection behavior (e.g. which url parameters to pass with the HTTP GET operation).
- Extended Schemas: Using an extended schema artifact type to dynamically create a conforming semantic type that accommodates the full variety of JSON field names and values in the result stream by sampling the data at schema creation time
- Extended Read Operators: Using an extended Read operator artifact type that uses the connection and schema information above to invoke the REST API service, parse the results and map each result object to a record. There is also an extended Read operator artifact type that performs a simple file rename operation as part of a final step in a multi-step flow as a means to avoid overwriting a prior job’s data files before the current job completes successfully.