Class: CSVDiff::CSVSource

Inherits:
Source
  • Object
show all
Defined in:
lib/csv-diff/csv_source.rb

Overview

Represents a CSV input (i.e. the left/from or right/to input) to the diff process.

Instance Attribute Summary

Attributes inherited from Source

#case_sensitive, #child_field_indexes, #child_fields, #data, #dup_count, #field_names, #index, #key_field_indexes, #key_fields, #line_count, #lines, #parent_field_indexes, #parent_fields, #path, #skip_count, #trim_whitespace, #warnings

Instance Method Summary collapse

Methods inherited from Source

#[], #index_source, #path?, #save_csv, #to_hash

Constructor Details

#initialize(source, options = {}) ⇒ CSVSource

Creates a new diff source.

A diff source must contain at least one field that will be used as the key to identify the same record in a different version of this file. If not specified via one of the options, the first field is assumed to be the unique key.

If multiple fields combine to form a unique key, the parent is assumed to be identified by all but the last field of the unique key. If finer control is required, use a combination of the :parent_fields and :child_fields options.

All key options can be specified either by field name, or by field index (0 based).

Parameters:

  • source (String|Array<Array>) —

    Either a path to a CSV file, or an Array of Arrays containing CSV data. If the :field_names option is not specified, the first line must contain the names of the fields.

  • options (Hash) (defaults to: {}) —

    An options hash.

Options Hash (options):

  • :encoding (String) —

    The encoding to use when opening the CSV file.

  • :csv_options (Hash) —

    Any options you wish to pass to CSV.open, e.g. :col_sep.

  • :field_names (Array<String>) —

    The names of each of the fields in source.

  • :ignore_header (Boolean) —

    If true, and :field_names has been specified, then the first row of the file is ignored.

  • :key_field (String) —

    The name of the field that uniquely identifies each row.

  • :key_fields (Array<String>) —

    The names of the fields that uniquely identifies each row.

  • :parent_field (String) —

    The name of the field(s) that identify a parent within which sibling order should be checked.

  • :child_field (String) —

    The name of the field(s) that uniquely identify a child of a parent.

  • :case_sensitive (Boolean) —

    If true (the default), keys are indexed as-is; if false, the index is built in upper-case for case-insensitive comparisons.

  • :include (Hash) —

    A hash of field name(s) or index(es) to regular expression(s). Only source rows whose field values satisfy the regular expressions will be indexed and included in the diff process.

  • :exclude (Hash) —

    A hash of field name(s) or index(es) to regular expression(s). Source rows with a field value that satisfies the regular expressions will be excluded from the diff process.



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# File 'lib/csv-diff/csv_source.rb', line 51

def initialize(source, options = {})
    super(options)
    if source.is_a?(String)
        require 'csv'
        mode_string = options[:encoding] ? "r:#{options[:encoding]}" : 'r'
        csv_options = options.fetch(:csv_options, {})
        @path = source
        # When you call CSV.open, it's best to pass in a block so that after it's yielded,
        # the underlying file handle is closed. Otherwise, you risk leaking the handle.
        @data = CSV.open(@path, mode_string, csv_options) do |csv|
             csv.readlines
        end
    elsif source.is_a?(Enumerable) && source.size == 0 || (source.size > 0 && source.first.is_a?(Enumerable))
        @data = source
    else
        raise ArgumentError, "source must be a path to a file or an Enumerable<Enumerable>"
    end
    index_source
end