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Torch Log Service

Global operation function

Flow control function

This topic describes the syntax and format of flow control functions, along with relevant scenario examples.

c_if function

This function processes logs that meet certain conditions. If no condition is met, no actions will be taken.

The conditions and actions in the function parameters must appear in pairs, and there must be at least one pair of condition and action combination.

If there are multiple true conditions, only the action for the first true condition is executed.

Function syntax/format

c_if(condition 1, action 1, condition 2, action 2, ……)​

The parameters are described below:

Parameters	Parameter type	Required	Default value	Value range	Description
Condition	Any	Yes	/	/	Expression or a combination of expressions. If they are not Boolean types, they will be converted to Boolean types before evaluation.
Actions	Global operation function	Yes	/	/	Global operation function or combinations.

Function examples

Scenario: When the original log contains the phone field, newly add the contact_type field.

Processing rules:

c_if(f_has("phone"), f_set("contact_type", "telephone"))

Log example

[
{
"user_name":"Smith",
"phone":"135xxxx5678"
},
{
"user_name":"Paul",
"city":"chengdu"
}
]

Processing result:

[
{
"user_name":"Smith",
"phone":"135xxxx5678",
"contact_type":"telephone"
},
{
"user_name":"Paul",
"city":"chengdu"
}
]

Tip

The first log contains the phone field and adds the contact_type field after processing. The second log does not contain the phone field, so the phone field is not added after processing.

c_if_else function

Process different logic based on condition evaluation. If the condition is true, perform action 1; otherwise, perform action 2.

Function syntax/format

c_if_else(condition, action 1, action 2)

The parameters are described below:

Parameters	Parameter type	Required	Default value	Value range	Description
Condition	Any	Yes	/	/	Expression or a combination of expressions. If they are not Boolean types, they will be converted to Boolean types before evaluation.
Operation 1	Global operation function	Yes	/	/	Global operation function or combinations.
Operation 2	Global operation function	Yes	/	/	Global operation function or combinations.

Function examples

Scenario: Determine whether a person is an adult based on the age field, and output the result to a new field is_adult.

Processing rules:

c_if_else(op_ge(v("age"), 18), f_set("is_adult", True), f_set("is_adult", False))

Log example

[
{
"name":"Agatha",
"age":"20"
},
{
"name":"Elvin",
"age":"17"
}
]

Processing result:

[
{
"name":"Agatha",
"age":"20",
"is_adult":true
},
{
"name":"Elvin",
"age":"17",
"is_adult":false
}
]

c_switch function

Process different logic based on condition evaluation. Based on multiple branch conditions, execute the action corresponding to the first true condition. If none of the conditions are met, the default action will be executed.

Function syntax/format

c_switch(condition 1, action 1, condition 2, action 2, ..., default=default action )​

The parameters are described below:

Parameters	Parameter type	Required	Default value	Value range	Description
Condition	Any	Yes	/	/	Expression or a combination of expressions. If they are not Boolean types, they will be converted to Boolean types before evaluation.
Actions	Global operation function	Yes	/	/	Global operation function or combinations.
default	Global operation function	Yes	/	/	Default operation, global operation function or combinations thereof.

Function examples

Scenario: Determine the region based on the city log field.

Processing rules:

c_switch(op_eq(v("city"), "chengdu"), f_set("region", "West"), op_eq(v("city"), "shanghai"), f_set("region", "East"))

Log example

[
{
"name":"Agatha",
"city":"chengdu"
},
{
"name":"Elvin",
"city":"shanghai"
}
]

Processing result:

[
{
"name":"Agatha",
"city":"chengdu",
"region":"West"
},
{
"name":"Elvin",
"city":"shanghai",
"region":"East"
}
]

c_compose function

Used to combine multiple operations. All operations should be global operation functions.

TLS will sequentially invoke the specified operations, transmitting, transforming, and finally returning the log data.

For a given log record, if any global operation deletes the log, TLS will not execute subsequent operations on it.

Function syntax/format

c_compose(action 1, action 2...)

The parameters are described below:

Parameters	Parameter type	Required	Default value	Value range	Description
Actions	Global operation function	Yes	/	/	Multiple global operation functions or combinations thereof.

Function examples

Scenario: When the log contains a content field, update its value to value1 and rename it to content_modified.

Processing rules:

c_if(f_has("content"),c_compose(f_set("content","value1"),f_rename("content","content_modified")))

Log example

{
"content":"value"
}

Processing result:

{
"content_modified":"value1"
}

Last updated: 2026.05.08 16:28:57