|
F.8 JSON Related Functions |
JSON Related Functions
JSON (JavaScript Object Notation) is a lightweight data format
commonly used for web APIs and data exchange. SheerPower provides
two powerful functions for working with JSON data:
JSON$() for converting SheerPower clusters into JSON
strings, and jsonutil$() for parsing and manipulating
existing JSON data. Together, these functions make it easy to
integrate SheerPower applications with web services and modern
data workflows.
JSON$() - Converting Clusters to JSON
The JSON$() function converts SheerPower cluster arrays into properly formatted JSON strings.
Syntax
string$ = JSON$(clustername [, row_option])
Where:
- clustername - The cluster to convert
- row_option - Optional row number. Use -1 for all rows (default)
Example 1: Simple Cluster Array
Convert a basic cluster array to JSON:
cluster person: id$, name$, age
add cluster person
person->id$ = "1"
person->name$ = "Alice"
person->age = 30
add cluster person
person->id$ = "2"
person->name$ = "Bob"
person->age = 25
json_output$ = JSON$(person)
print json_output$
Output:
[
{"id$":"1", "name$":"Alice", "age":30},
{"id$":"2", "name$":"Bob", "age":25}
]
Example 2: Nested Cluster Array
Convert clusters with nested structures:
cluster address: street$, city$, zip$
cluster person: id$, name$, age, address->address
add cluster person
person->id$ = "1"
person->name$ = "Alice"
person->age = 30
person->address->street$ = "123 Main St"
person->address->city$ = "Springfield"
person->address->zip$ = "12345"
add cluster person
person->id$ = "2"
person->name$ = "Bob"
person->age = 25
person->address->street$ = "456 Elm St"
person->address->city$ = "Shelbyville"
person->address->zip$ = "67890"
json_output$ = JSON$(person)
print json_output$
Output:
[
{
"id$":"1",
"name$":"Alice",
"age":30,
"address":{
"street$":"123 Main St",
"city$":"Springfield",
"zip$":"12345"
}
},
{
"id$":"2",
"name$":"Bob",
"age":25,
"address":{
"street$":"456 Elm St",
"city$":"Shelbyville",
"zip$":"67890"
}
}
]
Example 3: Single Row Output
Extract just one row as JSON:
// Using the person cluster from above
single_person$ = JSON$(person, 1) // Get first row only
print single_person$
Output:
{"id$":"1", "name$":"Alice", "age":30, "address":{"street$":"123 Main St", "city$":"Springfield", "zip$":"12345"}}
jsonutil$() - Working with JSON Data
The jsonutil$() function parses, extracts, and manipulates JSON data using JSON Pointer syntax.
Syntax
result$ = jsonutil$(json_input$ [, json_pointer$])
Where:
- json_input$ - The JSON string to process
- json_pointer$ - Optional JSON Pointer path to extract specific values
Example 1: Extracting Values
Extract specific values from JSON:
json_data$ = '{"name":"Alice","age":30,"city":"Springfield"}'
name$ = jsonutil$(json_data$, '/name')
age$ = jsonutil$(json_data$, '/age')
city$ = jsonutil$(json_data$, '/city')
print "Name: "; name$
print "Age: "; age$
print "City: "; city$
Output:
Name: Alice
Age: 30
City: Springfield
Example 2: Working with Arrays
Extract values from JSON arrays:
json_array$ = '[{"name":"Alice","age":30},{"name":"Bob","age":25}]'
first_name$ = jsonutil$(json_array$, '/0/name')
second_age$ = jsonutil$(json_array$, '/1/age')
print "First person: "; first_name$
print "Second person age: "; second_age$
Output:
First person: Alice
Second person age: 25
Example 3: Getting All Keys
Extract all keys from a JSON object:
json_data$ = '{"name":"Alice","age":30,"city":"Springfield"}'
keys$ = jsonutil$(json_data$, '')
print "Available keys: "; keys$
Output:
Available keys: ["name","age","city"]
Example 4: Converting JSON to Clusters
Convert JSON data back into SheerPower clusters:
cluster employee: name$, age, department$
json_data$ = '[
{"name":"Alice","age":30,"department":"Engineering"},
{"name":"Bob","age":25,"department":"Sales"},
{"name":"Carol","age":35,"department":"Marketing"}
]'
jsonutil$(json_data$, 'to_cluster:employee')
print "Employees:"
for each employee
print employee->name$; " ("; employee->age; ") - ";
print employee->department$
next employee
Output:
Employees:
Alice (30) - Engineering
Bob (25) - Sales
Carol (35) - Marketing
Practical Use Cases
Web API Integration
Combine both functions for complete API workflows:
// Prepare data to send to an API
cluster order: id$, product$, quantity, price
add cluster order
order->id$ = "ORD001"
order->product$ = "Widget"
order->quantity = 5
order->price = 12.99
// Convert to JSON for API request
api_request$ = JSON$(order, 1)
print "Sending to API: "; api_request$
// Simulate API response
api_response$ = '{"status":"success","order_id":"ORD001","total":64.95}'
// Extract response data
status$ = jsonutil$(api_response$, '/status')
total$ = jsonutil$(api_response$, '/total')
print "API Status: "; status$
print "Order Total: $"; total$
Note: These JSON functions make SheerPower
applications fully compatible with modern web services, REST APIs,
and JSON-based data exchange formats. The combination of
JSON$() and jsonutil$() provides complete
round-trip JSON support.
|
Hide Description
|
|
|
Results are shown here. Enter or modify the code below, and then click on RUN |
|
Looking for the full power of Sheerpower?
Check out the Sheerpower website. Free to download. Free to use. |
