# tWriteJSONField Standard properties These properties are used to configure tWriteJSONField running in the Standard Job framework. The Standard tWriteJSONField component belongs to the Processing family. The component in this framework is available in all Talend products. ## Basic settings | Output Column | Select the column from the list for holding the JSON string
generated. The columns in the list are defined in the output schema. | | --- | --- | | Configure JSON Tree | Opens the interface to create the JSON data
structure. For more information, see [Configuring a JSON Tree](https://help.qlik.com/talend/en-US/components/7.3/processing/configuring-a-json-tree). | | Schema and Edit Schema | A schema is a row description. It defines the number of fields
(columns) to be processed and passed on to the next component. When you create a Spark
Job, avoid the reserved word line when naming the
fields.

Information noteNote: In the output schema, a column is null by default; only the column selected
from Output Column holds the JSON string generated. You
can add rows in the Group by table and specify other
output columns to hold Group-by values.

Click Edit
schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

| | | Built-In: You create and store the schema locally for this component
only. | | | Repository: You have already created the schema and stored it in the
Repository. You can reuse it in various projects and Job designs. | | Sync columns | Click to synchronize the output file schema
with the input file schema. The Sync function only displays once the Row
connection is linked with the output component. | | Group by | Define the aggregation set, the columns you
want to use to regroup the data.

Information noteWarning:

Make sure that the data to be grouped is in
sequential order. | | Remove root node | Select this check box to remove the root node
from the JSON field generated. | ## Advanced settings | Quote all not-null
values | Select this check box to surround all values including number
and boolean values in the generated JSON field with double quotation marks.

Clear this check box to surround only string values in the
generated JSON field with double quotation marks. | | --- | --- | | Quote also null values | Select this check box to surround all the strings with the value of null
in the generated JSON field with double quotation marks.

This option is available when Quote all not-null values is
selected. | | tStatCatcher Statistics | Select this check box to gather the Job
processing metadata at a Job level as well as at each component level. | ## Global Variables | Global Variables | ERROR\_MESSAGE: the error message generated by the component when an
error occurs. This is an After variable and it returns a string. This variable functions
only if the Die on error check box
is cleared, if the component has this check
box.


NB\_LINE: the number
of rows read by an input component or transferred to an output component. This is an
After variable and it returns an integer.

A Flow variable functions during the execution of a component
while an After variable functions after the execution of the component.

To fill up a field or expression with a
variable, press Ctrl + Space to
access the variable list and choose the variable to use from it.

For further information about variables, see *Talend Studio*
*User Guide*. | | --- | --- | ## Usage | **Usage rule** | Preceded by an input component, this component
wraps the incoming data into a JSON field. | | --- | --- | Information noteNote: For any field with the null value, this component writes a pair of square brackets ([]). If needed, you can remove or replace them using a regular expression in a tJavaRow component next to the tWriteJSONField component. For exmaple: ``` output_row.rootNode = input_row.rootNode.replaceAll("\\[\\]", ""); ```