@svizzle/file/read

Methods

(static) readCsv(csvPath, conversionFnopt, withHeaderopt) → {promise}

Source:

tools/file/src/read.js, line 233

Since:

0.1.0

See:

https://github.com/d3/d3-dsv#dsv_parse

[node environment] Return a promise that reads and then parses a csv file. You can create a conversionFn using transformValues() from @svizzle/utils

Example

$ cat source/withHeader.csv
name,amount
annie,200
joe,100

> readCsv('source/withHeader.csv', row => ({
	name: row.name,
	amount: Number(row.amount)
}))
.then(x => console.log(x))
.catch(err => console.error(err))

[{name: 'annie', amount: 200}, {name: 'joe', amount: 100}]

$ cat source/withNoHeader.csv
annie,200
joe,100

> readCsv('source/withNoHeader.csv', row => ({
	name: row.name,
	amount: Number(row.amount)
}), false)
.then(x => console.log(x))
.catch(err => console.error(err))

[{name: 'annie', amount: 200}, {name: 'joe', amount: 100}]

Parameters:

Name	Type	Attributes	Default	Description
`csvPath`	string			The filepath of the CSV file to read.
`conversionFn`	function	<optional>	`x=>x`	A function invoked for each row to convert columns values.
`withHeader`	boolean	<optional>	`true`	Does the first line contain the header?

Returns:

@sideEffects: fs.readFile

Type: promise

(static) readDir(dirPath) → {promise}

Source:

tools/file/src/read.js, line 63

Since:

0.4.0

[node environment] Return a promise that reads the directory at the provided path.

Example

> readDir('source/dir/')
.then(x => console.log(x))
.catch(err => console.error(err))

['dir1', 'dir2', 'file1.txt', 'file2.txt', 'folder1', 'folder2']

Parameters:

Name	Type	Description
`dirPath`	string

Returns:

@sideEffects: fs.readdir

Type: promise

(static) readDirFiles(dirPath, filterPathFn, parseFn) → {promise}

Source:

tools/file/src/read.js, line 121

Since:

0.9.0

[node environment] Return a promise that reads files in the given directory with a file path satisfying the provided criteria, returning the array with their content parsed with the provided parser.

Example

$ ls -a source/dir
.   01.csv  foo.txt  .foo
..  02.csv  bar.json
$ cat source/dir/.foo
hidden foo
$ cat source/dir/foo.txt
foo
$ cat source/dir/bar.json
{"a": 1}
$ cat source/dir/01.csv
a,b
foo,1
bar,2
$ cat source/dir/02.csv
foo,1
bar,2

> readDirFiles('source/dir/')
.then(x => console.log(x))
.catch(err => console.error(err))

[
	'a,b\nfoo,1\nbar,2',
	'foo,1\nbar,2',
	'foo',
	'{"a": 1}',
	'hidden foo'
]

> readDirFiles('source/dir/', isPathCSV)
.then(x => console.log(x))
.catch(err => console.error(err))

['a,b\nfoo,1\nbar,2', 'foo,1\nbar,2']

> readDirFiles('source/dir/', isPathCSV, d3.csvParseRows)
.then(x => console.log(x))
.catch(err => console.error(err))

[
	[['a', 'b'], ['foo', '1'], ['bar', '2']],
	[['foo', '1'], ['bar', '2']]
]

Parameters:

Name	Type	Description
`dirPath`	string	the directory path
`filterPathFn`	function	(String -> Boolean) predicate to filter the filepaths (e.g. ()
`parseFn`	function	(String -> Any) target file parser

Returns:

@sideEffects: fs.readdir, fs.readFile

Type: promise

(static) readDirFilesIndexed(dirPath, filterPathFn, parseFn, withFilepathAsKeyopt) → {promise}

Source:

tools/file/src/read.js, line 171

Since:

0.9.0

[node environment] Return a promise that reads files in the given directory with a file path satisfying the provided criteria, returning their content parsed with the provided parser indexed by file name. From v0.10.0, withFilepathAsKey drives what to get as keys.

Example

$ ls -a test_assets/
.   .foo  ab.csv    foo.txt
..  .bar  rows.csv  bar.json
$ cat test_assets/ab.csv
a,b
foo,1
bar,2
$ cat test_assets/rows.csv
foo,1
bar,2

> readDirFilesIndexed('source/dir/', isPathCSV, d3.csvParseRows)
.then(x => console.log(x))
.catch(err => console.error(err))

{
	'ab.csv': [['a', 'b'], ['foo', '1'], ['bar', '2']],
	'rows.csv': [['foo', '1'], ['bar', '2']]
}

Parameters:

Name	Type	Attributes	Default	Description
`dirPath`	string			the directory path
`filterPathFn`	function			(String -> Boolean) predicate to filter the filepaths (e.g. ()
`parseFn`	function			(String -> Any) target file parser
`withFilepathAsKey`	boolean	<optional>	`false`	defaults to `false`, to return objects with file names as keys; if `true`, keys are file paths.

Returns:

@sideEffects: fs.readdir, fs.readFile

Type: promise

(static) readDsv(csvPath, separator, conversionFnopt, withHeaderopt) → {promise}

Source:

tools/file/src/read.js, line 287

Since:

0.4.0

See:

https://github.com/d3/d3-dsv#dsv_parse

[node environment] Return a promise that reads and then parses a file. You can create a conversionFn using transformValues() from @svizzle/utils

Example

$ cat source/withHeader.txt
name;amount
annie;200
joe;100

> readDsv('source/withHeader.txt', ({name, amount}) => ({
	name,
	amount: Number(amount)
}), ';')
.then(x => console.log(x))
.catch(err => console.error(err))

[{name: 'annie', amount: 200}, {name: 'joe', amount: 100}]

$ cat source/withNoHeader.txt
annie|200
joe|100

> readDsv('source/withNoHeader.txt', ([name, amount]) => ({
	name,
	amount: Number(amount)
}), '|', false)
.then(x => console.log(x))
.catch(err => console.error(err))

[{name: 'annie', amount: 200}, {name: 'joe', amount: 100}]

Parameters:

Name	Type	Attributes	Default	Description
`csvPath`	string			The filepath of the CSV file to read.
`separator`	string			Separator string.
`conversionFn`	function	<optional>	`x=>x`	A function invoked for each row to convert columns values.
`withHeader`	boolean	<optional>	`true`	Does the first line contain the header?

Returns:

@sideEffects: fs.readFile

Type: promise

(static) readExportedJson(jsFilePath) → {promise}

Source:

tools/file/src/read.js, line 459

Since:

0.14.0

[node environment] Return a promise that reads the file at the provided js path and returns the exported value.

Example

$ cat source/object.js
export default {"a": 1}

> readExportedJson('source/object.js')
.then(x => console.log(x))
.catch(err => console.error(err))

{a: 1}

$ cat source/array.js
export default [1, 2, 3];

> readExportedJson('source/array.js')
.then(x => console.log(x))
.catch(err => console.error(err))

[1, 2, 3]

Parameters:

Name	Type	Description
`jsFilePath`	string

Returns:

@sideEffects: fs.readFile

Type: promise

(static) readFile(filePath, encodingopt) → {promise}

Source:

tools/file/src/read.js, line 45

Since:

0.4.0

[node environment] Return a promise that reads the file at the provided path.

Example

> readFile('source/path.txt')
.then(x => console.log(x))
.catch(err => console.error(err))

<Buffer 49 27 6d ...0a>

> readFile('source/path.txt', 'utf-8')
.then(x => console.log(x))
.catch(err => console.error(err))

'the file content'

Parameters:

Name	Type	Attributes	Default	Description
`filePath`	string
`encoding`	string	<optional>	`null`	Encoding supported by Node Buffer

Returns:

@sideEffects: fs.readFile

Type: promise

(static) readJson(jsonPath) → {promise}

Source:

tools/file/src/read.js, line 372

Since:

0.1.0

[node environment] Return a promise that reads and then parses a json file.

Example

> readJson('source/filepath.json')
.then(x => console.log(x))
.catch(err => console.error(err))

[{name: 'annie', amount: 200}, {name: 'joe', amount: 100}]

Parameters:

Name	Type	Description
`jsonPath`	string	The filepath of the JSON file to read.

Returns:

@sideEffects: fs.readFile

Type: promise

(static) readJsonDir(dirPath) → {promise}

Source:

tools/file/src/read.js, line 394

Since:

0.1.0

[node environment] Return a promise returning an array of objects of the JSON files of a directory, not recursively.

Example

> readJsonDir('source/path/')
.then(x => console.log(x))
.catch(err => console.error(err))

[{'a': 1}, '{'a': 2}', '{'a': 2}']

Parameters:

Name	Type	Description
`dirPath`	string	The path of the directory containing the JSON files to read.

Returns:

@sideEffects: fs.readdir, fs.readFile

Type: promise

(static) readTsv(tsvPath, conversionFnopt, withHeaderopt) → {promise}

Source:

tools/file/src/read.js, line 344

Since:

0.3.0

See:

https://github.com/d3/d3-dsv#dsv_parse

[node environment] Return a promise that reads and then parses a tsv file. You can create a conversionFn using transformValues() from @svizzle/utils

Example

$ cat source/withHeader.txt
name\tamount
annie\t200
joe\t100

> readTsv('source/withHeader.txt', ({name, amount}) => ({
	name,
	amount: Number(amount)
}))
.then(x => console.log(x))
.catch(err => console.error(err))

[{name: 'annie', amount: 200}, {name: 'joe', amount: 100}]

$ cat source/withNoHeader.txt
annie\t200
joe\t100

> readTsv('source/withNoHeader.txt', ([name, amount]) => ({
	name,
	amount: Number(amount)
}), false)
.then(x => console.log(x))
.catch(err => console.error(err))

[{name: 'annie', amount: 200}, {name: 'joe', amount: 100}]

Parameters:

Name	Type	Attributes	Default	Description
`tsvPath`	string			The filepath of the TSV file to read.
`conversionFn`	function	<optional>	`x=>x`	A function invoked for each row to convert columns values,
`withHeader`	boolean	<optional>	`true`	Does the first line contain the header?

Returns:

@sideEffects: fs.readFile

Type: promise

(static) readYaml(yamlPath) → {promise}

Source:

tools/file/src/read.js, line 425

Since:

0.13.0

[node environment] Return a promise that reads and then parses a YAML file.

Example

> readYaml('source/filepath.yaml')
.then(x => console.log(x))
.catch(err => console.error(err))

{
	foo: [{a: 1}, {b: 2}],
	bar: [1, 2, 3],
}

Parameters:

Name	Type	Description
`yamlPath`	string	The filepath of the YAML file to read.

Returns:

@sideEffects: fs.readFile

Type: promise