JSON Templating engine is commonly used to configure many of our extensions.
JSON Templating Syntax
The basic and most commonly used syntax is for getting values from the annotation object:
{
"some_field": "@{schema_id_of_datapoint}"
}
See also the $DATAPOINT_VALUE$
section below for more verbose syntax.
JSON Templating Operators
Operators are a special syntax that can be used to perform various complex operations when working with JSON.
$DATAPOINT_MAPPING$
Returns rendered template specified in mapping
for certain value of schema_id
.
Example
{
"_ns_type": {
"$DATAPOINT_MAPPING$": {
"schema_id": "document_type",
"mapping": {
"tax_credit": "VendorCredit",
"tax_invoice": "VendorBill"
},
"fallback_mapping": "Vendor" // optional
}
}
}
This template will return the following for document_type
with value tax_credit
:
{ "_ns_type": "VendorCredit" }
Similarly, this template will return the following for tax_invoice
value:
{ "_ns_type": "VendorBill" }
Finally, the template will return the _ns_type
of Vendor
if no other value is found. This value can be omitted which will default to null
.
Available configuration options
Configuration option | Description | Required | Default |
---|---|---|---|
| Schema ID of the datapoint. | YES | |
| Mapping of the datapoint value (schema_id). | YES | |
| Default template that will be used if template for found datapoint value is not provided in the mapping. | NO | null |
$DATAPOINT_VALUE$
$DATAPOINT_VALUE$
is a more verbose syntax for @{schema_id}
. In other words, the following examples are identical:
{
"externalId": "@{ns_external_id_generated}"
}
Identical to:
{
"externalId": {
"$DATAPOINT_VALUE$": {
"schema_id": "ns_external_id_generated",
"value_type": "string"
}
}
}
While the latter might seem unnecessary, it is needed when we want to cast the value to a certain type. For example:
{
"tranDate": {
"$DATAPOINT_VALUE$": {
"schema_id": "date_issue",
"value_type": "iso_datetime"
}
}
}
Available configuration options
Configuration option | Description | Required | Default |
---|---|---|---|
| Schema ID of the datapoint. | YES | |
| Type to which the value should be converted. Supported types are: | NO |
|
$FOR_EACH_SCHEMA_ID$
Iterates over multiline schema IDs, typically line items.
Example
{
"items": {
"$FOR_EACH_SCHEMA_ID$": {
"schema_id": "line_item",
"mapping": {
"_ns_type": "VendorBillItem",
"quantity": "@{item_quantity}",
"description": "@{item_description}"
}
}
}
}
Will render:
{
"items": [
{
"_ns_type": "VendorBillItem",
"quantity": "1",
"description": "Some description 1"
},
{
"_ns_type": "VendorBillItem",
"quantity": "2",
"description": "Some description 2"
}
// …
]
}
Inside the for-loop block, you can access a special variables (schema_loop
):
schema_loop.index
for current iteration of the loop indexed from 1schema_loop.index0
for current iteration of the loop indexed from 0
Available configuration options
Configuration option | Description | Required | Default |
---|---|---|---|
| Schema ID of the datapoint. | YES | |
| Mapping template that will be rendered for each element found with the given schema_id. | YES | |
| Mapping template that will be rendered if no element with the given schema_id is found. | NO |
|
$IF_DATAPOINT_VALUE$
Renders the provided mapping
template if the value of the given schema_id
is equal to value
. Otherwise, the whole parent key is skipped.
Note that if element with given schema_id
is not found or multiple with the same schema_id
is found an exception is raised.
Example
{
"Other_Field": 123,
"Company_Reference": {
"$IF_DATAPOINT_VALUE": {
"schema_id": "company_match",
"value": "my_company",
"mapping": {
"field_1": 456,
"field_2": 789
}
}
}
}
If company_match
has value my_company
the output will be:
{
"Other_Field": 123,
"Company_Reference": {
"field_1": 456,
"field_2": 789
}
}
If company_match
has value that is different from my_company
the output will be:
{
"Other_Field": 123
}
Available configuration options
Configuration option | Description | Required | Default |
---|---|---|---|
| Schema ID of the relevant datapoint. | YES | |
| Conditional (expected) value in | YES | |
| Mapping template that will be rendered if | YES |
$IF_SCHEMA_ID$
Similar to $FOR_EACH_SCHEMA_ID$
operation: it checks the existence of schema_id
, and it either outputs mapping
if the schema_id
points to a non-empty value or fallback_mapping
otherwise.
Note that if you don't specify the fallback_mapping
, it will skip the whole parent key!
Example
{
"dueDate": {
"$IF_SCHEMA_ID$": {
"schema_id": "date_due",
"mapping": {
"$DATAPOINT_VALUE$": {
"schema_id": "date_due",
"value_type": "iso_datetime"
}
}
}
}
}
Available configuration options
Configuration option | Description | Required | Default |
---|---|---|---|
| Schema ID of the datapoint. | YES | |
| Mapping template that will be rendered if | YES | |
| Mapping template that will be rendered if no element with the given | NO |