---json
{
    "aliases": [
        { "path": ":howto:templating:create_json_from_tabular_data" }
    ],
    "description": "This howto will show you how to create a  JSON file\nfrom tabular data with the template operation and a JSON template",
    "low_quality_page": "false",
    "page_id": "sn8nysvwhcy6we0r2a2ec"
}
---
====== Tabulify HowTo - How to create JSON file(s) from Tabular data with a JSON template ======

===== A propos =====
This [[howto:howto|howto]] will show you:
  * how to create a <icon name="carbon:json" /> [[docs:resource:json|JSON data resource]]
  * from [[docs:resource:tabular|tabular data]]
  * with the [[docs:op:template|template operation]]
  * and the [[docs:templating:json|JSON template]]


===== Steps =====

<unit display="none">
<code bash>
tabul data drop --no-strict-selection books.json@tmp
</code>
</unit>

==== The tabular source data ====
In this [[howto:howto|howto]], we will use as source ''books catalog data'' that are contained in
  * the ''books.csv'' [[docs:resource:csv|csv file]]
  * stored in the [[docs:connection:howto|howto directory connection]]

<note>
You can also used any other [[docs:resource:tabular|tabular data resources]].
</note>

With the [[docs:tabul:data:print|data print]] command, we can see the content.
<unit>
<code bash>
tabul data print books.csv@howto
</code>
<console>
books.csv@howto
asin            description                                   price   group
-------------   -------------------------------------------   -----   ----------
B007US9NA8      The New Encyclopedia of Modern Bodybuilding   27.18   Sports
1439199191      How To Win Friends And Influence People       27.18   Psychology
9780465050659   The Design of Everyday Things                  9.99   Design
9780465050659   The Design of Everyday Things                  9.99   Psychology
B00555X8OA      Thinking, Fast and Slow                        8.85   Decision
B00555X8OA      Thinking, Fast and Slow                        8.85   Psychology
</console>
</unit>

==== The JSON template ====

The [[docs:templating:json|JSON template]] is a [[docs:templating:templating|template]] that represents the structure of the [[docs:resource:json|JSON resource]] that should be created that contains variables in the form ''${name}'' where ''name'' should match the column name of the source.

<unit>
<file javascript books_template.json>
{
  "${group}": {
    "${asin}": {
      "price": "${price}",
      "description": "${description}"
    }
  }
}

</file>
</unit>
where:
  * the variable ''%%${group}%%'' matches the ''group'' column of the ''books.csv'' source
  * the variable ''%%${asin}%%'' matches the ''asin'' column of the ''books.csv'' source
  * the variable ''%%${price}%%'' matches the ''price'' column of the ''books.csv'' source
  * the variable ''%%${description}%%'' matches the ''description'' column of the ''books.csv'' source

==== The template operation ====

=== Tabul Data Template Command ===

By running the below [[docs:tabul:data:template|tabul data template operation]], we will:
  * create a ''books.json'' [[docs:resource:json|json file]]
  * into the [[docs:connection:tmp|temp connection directory]]
  * that has been created:
      * from the ''books_template.json'' [[docs:templating:json|JSON template]] located in the [[docs:connection:howto|howto directory]]
      * and the [[docs:flow:source|source]] [[docs:resource:csv|csv file]] ''books.csv'' located in the [[docs:connection:howto|howto directory]]
<unit>
<code bash>
tabul data template --template-selectors books_template.json@howto books.csv@howto books.json@tmp
</code>
<console>
Transfer results
input                                  target           latency   record_count   error_code   error_message
------------------------------------   --------------   -------   ------------   ----------   -------------
favorite_books_books_template@memory   books.json@tmp   0.13s                1
</console>
</unit>

==== The JSON file created ====
With the [[docs:tabul:data:print|data print command]], you can see the [[docs:resource:json|json file content]] created.
<unit>
<code bash>
# type text because by default, a json file is seen as one JSON document, one record, one line
tabul data print --type text books.json@tmp
</code>
<console javascript>
{
  "Sports": {
    "B007US9NA8": {
      "price": "27.18",
      "description": "The New Encyclopedia of Modern Bodybuilding"
    }
  },
  "Psychology": {
    "1439199191": {
      "price": "27.18",
      "description": "How To Win Friends And Influence People"
    },
    "9780465050659": {
      "price": "9.99",
      "description": "The Design of Everyday Things"
    },
    "B00555X8OA": {
      "price": "8.85",
      "description": "Thinking, Fast and Slow"
    }
  },
  "Design": {
    "9780465050659": {
      "price": "9.99",
      "description": "The Design of Everyday Things"
    }
  },
  "Decision": {
    "B00555X8OA": {
      "price": "8.85",
      "description": "Thinking, Fast and Slow"
    }
  }
}
</console>
</unit>