initial commit.

node_modules/json2csv/lib/JSON2CSVParser.js

@@ -0,0 +1,81 @@
+'use strict';
+
+const JSON2CSVBase = require('./JSON2CSVBase');
+const { fastJoin, flattenReducer } = require('./utils');
+
+class JSON2CSVParser extends JSON2CSVBase {
+  constructor(opts) {
+    super(opts);
+    if (this.opts.fields) {
+      this.opts.fields = this.preprocessFieldsInfo(this.opts.fields);
+    }
+  }
+  /**
+   * Main function that converts json to csv.
+   *
+   * @param {Array|Object} data Array of JSON objects to be converted to CSV
+   * @returns {String} The CSV formated data as a string
+   */
+  parse(data) {
+    const processedData = this.preprocessData(data);
+
+    if (!this.opts.fields) {
+      this.opts.fields = processedData
+        .reduce((fields, item) => {
+          Object.keys(item).forEach((field) => {
+            if (!fields.includes(field)) {
+              fields.push(field)
+            }
+          });
+
+          return fields
+        }, []);
+      
+      this.opts.fields = this.preprocessFieldsInfo(this.opts.fields);
+    }
+
+    const header = this.opts.header ? this.getHeader() : '';
+    const rows = this.processData(processedData);
+    const csv = (this.opts.withBOM ? '\ufeff' : '')
+      + header
+      + ((header && rows) ? this.opts.eol : '')
+      + rows;
+
+    return csv;
+  }
+
+  /**
+   * Preprocess the data according to the give opts (unwind, flatten, etc.)
+    and calculate the fields and field names if they are not provided.
+   *
+   * @param {Array|Object} data Array or object to be converted to CSV
+   */
+  preprocessData(data) {
+    const processedData = Array.isArray(data) ? data : [data];
+
+    if (!this.opts.fields && (processedData.length === 0 || typeof processedData[0] !== 'object')) {
+      throw new Error('Data should not be empty or the "fields" option should be included');
+    }
+
+    if (this.opts.transforms.length === 0) return processedData;
+
+    return processedData
+      .map(row => this.preprocessRow(row))
+      .reduce(flattenReducer, []);
+  }
+
+  /**
+   * Create the content row by row below the header
+   *
+   * @param {Array} data Array of JSON objects to be converted to CSV
+   * @returns {String} CSV string (body)
+   */
+  processData(data) {
+    return fastJoin(
+      data.map(row => this.processRow(row)).filter(row => row), // Filter empty rows
+      this.opts.eol
+    );
+  }
+}
+
+module.exports = JSON2CSVParser;