Added 'CSV to JSON' and 'JSON to CSV' operations. Closes #277

This commit is contained in:
n1474335 2018-11-09 17:40:19 +00:00
parent 42b956e402
commit 863bdffa84
5 changed files with 160 additions and 2 deletions

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@ -573,6 +573,10 @@ class Utils {
cell = "";
lines.push(line);
line = [];
// Skip next byte if it is also a line delim (e.g. \r\n)
if (lineDelims.indexOf(next) >= 0 && next !== b) {
i++;
}
} else {
cell += b;
}

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@ -54,7 +54,9 @@
"From MessagePack",
"To Braille",
"From Braille",
"Parse TLV"
"Parse TLV",
"CSV to JSON",
"JSON to CSV"
]
},
{

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@ -0,0 +1,80 @@
/**
* @author n1474335 [n1474335@gmail.com]
* @copyright Crown Copyright 2018
* @license Apache-2.0
*/
import Operation from "../Operation";
import OperationError from "../errors/OperationError";
import Utils from "../Utils";
/**
* CSV to JSON operation
*/
class CSVToJSON extends Operation {
/**
* CSVToJSON constructor
*/
constructor() {
super();
this.name = "CSV to JSON";
this.module = "Default";
this.description = "Converts a CSV file to JSON format.";
this.infoURL = "https://wikipedia.org/wiki/Comma-separated_values";
this.inputType = "string";
this.outputType = "JSON";
this.args = [
{
name: "Cell delimiters",
type: "binaryShortString",
value: ","
},
{
name: "Row delimiters",
type: "binaryShortString",
value: "\\r\\n"
},
{
name: "Format",
type: "option",
value: ["Array of dictionaries", "Array of arrays"]
}
];
}
/**
* @param {string} input
* @param {Object[]} args
* @returns {JSON}
*/
run(input, args) {
const [cellDelims, rowDelims, format] = args;
let json, header;
try {
json = Utils.parseCSV(input, cellDelims.split(""), rowDelims.split(""));
} catch (err) {
throw new OperationError("Unable to parse CSV: " + err);
}
switch (format) {
case "Array of dictionaries":
header = json[0];
return json.slice(1).map(row => {
const obj = {};
header.forEach((h, i) => {
obj[h] = row[i];
});
return obj;
});
case "Array of arrays":
default:
return json;
}
}
}
export default CSVToJSON;

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@ -0,0 +1,72 @@
/**
* @author n1474335 [n1474335@gmail.com]
* @copyright Crown Copyright 2018
* @license Apache-2.0
*/
import Operation from "../Operation";
import OperationError from "../errors/OperationError";
/**
* JSON to CSV operation
*/
class JSONToCSV extends Operation {
/**
* JSONToCSV constructor
*/
constructor() {
super();
this.name = "JSON to CSV";
this.module = "Default";
this.description = "Converts JSON data to a CSV.";
this.infoURL = "https://wikipedia.org/wiki/Comma-separated_values";
this.inputType = "JSON";
this.outputType = "string";
this.args = [
{
name: "Cell delimiter",
type: "binaryShortString",
value: ","
},
{
name: "Row delimiter",
type: "binaryShortString",
value: "\\r\\n"
}
];
}
/**
* @param {JSON} input
* @param {Object[]} args
* @returns {string}
*/
run(input, args) {
const [cellDelim, rowDelim] = args;
try {
// If the JSON is an array of arrays, this is easy
if (input[0] instanceof Array) {
return input.map(row => row.join(cellDelim)).join(rowDelim) + rowDelim;
}
// If it's an array of dictionaries...
const header = Object.keys(input[0]);
return header.join(cellDelim) +
rowDelim +
input.map(
row => header.map(
h => row[h]
).join(cellDelim)
).join(rowDelim) +
rowDelim;
} catch (err) {
throw new OperationError("Unable to parse JSON to CSV: " + err);
}
}
}
export default JSONToCSV;

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@ -33,7 +33,7 @@ class ToTable extends Operation {
{
"name": "Row delimiters",
"type": "binaryShortString",
"value": "\\n\\r"
"value": "\\r\\n"
},
{
"name": "Make first row header",