JSON PARSE ARRAY

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4D v20.6

JSON

JSON PARSE ARRAY


JSON PARSE ARRAY ( jsonString ; array )

Parameter	Type	Description
jsonString	String	JSON string to parse
array	Array	Array containing result from parsing of JSON string

Description

The JSON PARSE ARRAY command parses the contents of a JSON-formatted string and puts the data extracted into the array parameter. This command deserializes the JSON data; it performs the opposite action of the JSON Stringify array command.

In jsonString, pass the JSON-formatted string whose contents you want to parse. This string must be formatted correctly, otherwise a parsing error is generated.

In array, pass an array of the desired type to receive the parsing results.

Note: Starting with 4D v16 R4, JSON PARSE ARRAY can usually be replaced by a call to JSON Parse that returns a collection. Collections are based on JSON arrays and allow to store data of mixed types, which provides more flexibility than arrays.

Example

In this example, data from fields of the records in a table are extracted and then placed in object arrays:

 C_OBJECT($ref)

 ARRAY OBJECT($sel;0)

 ARRAY OBJECT($sel2;0)

 C_TEXT(v_String)

 

 OB SET($ref;"name";->[Company]Company Name)

 OB SET($ref;"city";->[Company]City)

 

 While(Not(End selection([Company])))

    $ref_company:=OB Copy($ref;True)

    APPEND TO ARRAY($sel;$ref_company)

  // $sel{1}={"name":"4D SAS","city":"Clichy"}

  // $sel{2}={"name":"MyComp","city":"Lyon"}

  // ...

    NEXT RECORD([Company])

 End while

 

 v_String:=JSON Stringify array($sel)

  // v_String= [{"name":"4D SAS","city":"Clichy"},{"name":"MyComp","city":"Lyon"}...]

 JSON PARSE ARRAY(v_String;$sel2)

  // $sel2{1}={"name":"4D SAS","city":"Clichy"}

  // $sel2{2}={"name":"MyComp","city":"Lyon"}

  //...