---json
{
    "aliases": [
        { "path": ":docs:resource:target_pattern" },
        { "path": ":docs:resource:target_template" }
    ],
    "page_id": "mcam443erusnv2r3xgrtd"
}
---
====== Template String ======


===== About =====
A ''template string'' is a template expression that generates a string such as the [[:docs:resource:path|path of resource]]




You can refer to this pattern:
  * in the [[docs:flow:template_data_uri|template data uri]] path.
  * or in an operation with a argument that accepts a ''template string''

===== Syntax =====

A target pattern is a string that contains at minimal a variable expression.

Variable Expression:
```bash
${prefix_variable_name}
# or
$prefix_variable_name
```
where ''prefix'' describe the type of variable provider

^ Prefix ^ Type ^ Type of variables ^
| ''record'' or ''rec'' | [[:docs:resource:record|record]] | [[#Record Column Values]] |
| ''input'' or ''in'' | [[:docs:flow:input|input data path]] | [[#Data Path Attributes]] |
| ''target'' or ''tar'' | [[:docs:flow:target|target data path]] | [[#Data Path Attributes]] |
| ''pipeline'' or ''pipe'' | [[:docs:flow:pipeline|pipeline]] | [[#Pipeline Attributes]] |

===== List of Variable Providers =====

Each step will describe the accepted variables providers




==== Glob Matched Groups ====


In the pattern, you can reference a [[docs:common:globbing|globbing matched wildcard]] from a [[data_selector|data source selector]] using the ''%%$x%%'' syntax where x indicates the index of a glob pattern. ie
      * ''%%$0%%'' defines the whole expression (ie the whole path)
      * ''%%$1%%'' defines the first matched wildcard
      * ''%%$2%%'' defines the second matched wildcard
      * and so on until ''%%$9%%''.


You can see the value of the back reference with the [[docs:tabul:data:list|tabul data list command]].
If you want to know the value of ''%%$1%%'', just ask for the attribute ''1''

Example with [[docs:system:tpcds|tpcds]] where we want to capture the name of the web table but without the prefix.
<unit>
<code bash>
tabul data list -a 1 web_*@tpcds
</code>
<console>
path          media_type     1
-----------   ------------   -------
web_page      sql/relation   page
web_returns   sql/relation   returns
web_sales     sql/relation   sales
web_site      sql/relation   site
</console>
</unit>
==== Data Path Attributes ====


In the template, you can reference any [[:docs:conf:attribute|attribute]] of a data path



Example for a [[docs:resource:logical_name|logical name]] of [[:docs:flow:input|input data resource]]
<code>
${input_logical_name}
</code>


You can see all available attributes with the [[docs:tabul:data:info|data info command]].

<unit>
<code bash>
tabul data info web_page@tpcds
</code>
<console>
Information about the data resource (web_page@tpcds)
attribute          value                                                                                              description
----------------   ------------------------------------------------------------------------------------------------   -----------------------------------------------------
ABSOLUTE_PATH      web_page                                                                                           The absolute path on the data system
ACCESS_TIME                                                                                                           The access time (access time)
COMMENT                                                                                                               A comment
CONNECTION         tpcds                                                                                              The connection name
COUNT                                                                                                                 The number of records
CREATION_TIME                                                                                                         The creation time (birth time)
DATA_URI           web_page@tpcds                                                                                     The data uri
KIND               relation                                                                                           The kind of media
LOGICAL_NAME       web_page                                                                                           The logical name
MD5                2d3f08a0ad007e5236ed694250e89721                                                                   The Md5 hash
MEDIA_SUBTYPE      relation                                                                                           The media subType
MEDIA_TYPE         sql/relation                                                                                       The media type
NAME               web_page                                                                                           The name of the data resource
PARENT                                                                                                                The parent
PATH               web_page                                                                                           The relative path to the default connection path
SHA384             0d3fcd0bd2dc1aa6c14a6ce4a4c8acff06a6194a4f56f4730bbb371aaf490da1fe318f9f11ba44157ffd53d501e2f551   The Sha384 hash
SHA384_INTEGRITY   sha384-DT/NC9LcGqbBSmzkpMis/wamGUpPVvRzC7s3Gq9JDaH+MY+fEbpEFX/9U9UB4vVR                            The sha384 value used in the html integrity attribute
SIZE                                                                                                                  The number of byte
TABULAR_TYPE       data                                                                                               The tabular type
UPDATE_TIME                                                                                                           The last update time (modify time)
</console>
</unit>

==== Pipeline Attributes ====

If your template is used in a pipeline, you can add any [[:docs:flow:pipeline#attributes|pipeline attributes]].

Example:
<code>
${pipeline_start_time}
</code>
==== Record Column Values ====

If your step is running on [[docs:flow:granularity|record level]] (Example: [[:docs:op:split|split]])
you can also add the record value of a column using the ''%%$rec_x%%'' or ''%%${rec_x}%%'' syntax where ''x'' should be replaced by the [[docs:resource:column|column name]].



Example:
<code>
${record_column_name}
${rec_column_name}
</code>