if_col_present

The simple use case. For more complex behaviour see <code>switch_pipeline()</code>.

A dataframe validation framework for package builders who use
dataframes as function parameters. It performs checks on column names, coerces
data-types, and checks grouping to make sure user inputs conform to a
specification provided by the package author. It provides a mechanism for
package authors to automatically document supported dataframe inputs and
selectively dispatch to functions depending on the format of a dataframe much
like S3 does for classes. It also contains some developer tools to make
working with and documenting dataframe specifications easier. It helps package
developers to improve their documentation and simplifies parameter validation
where dataframes are used as function parameters.

Robert Challen

interfacer

Define and Enforce Contracts for Dataframes as Function
Parameters

if_col_present function

<dl><dt>df</dt>
<dd>a dataframe</dd>
<dt>col</dt>
<dd>a column name</dd>
<dt>if_present</dt>
<dd>a <code>purrr</code> style function to execute on the dataframe if the
column is present (or a plain value)</dd>
<dt>if_missing</dt>
<dd>a <code>purrr</code> style function to execute on the dataframe if the
column is missing (or a plain value)</dd></dl>

Arguments

Execute a function or return a value if a column in present in a dataframe — if_col_present

<dl>

<dt>df</dt>
<dd>a dataframe</dd>


<dt>col</dt>
<dd>a column name</dd>


<dt>if_present</dt>
<dd>a <code>purrr</code> style function to execute on the dataframe if the
column is present (or a plain value)</dd>


<dt>if_missing</dt>
<dd>a <code>purrr</code> style function to execute on the dataframe if the
column is missing (or a plain value)</dd>

</dl>

if_col_present: Execute a function or return a value if a column in present in a dataframe

Description

Usage

Value

Arguments

Examples