How do I download data trees to CSV? - tabulator

Question

How can I export nested tree data as a CSV file when using Tabulator? I tried using the table.download("csv","data.csv") function, however, only the top-level data rows are exported.
It looks like a custom file formatter or another option may be necessary to achieve this. It seems silly to re-write the CSV downloader, so while poking around the csv downloader in the download.js module, it looks like maybe adding a recursive function to the row parser upon finding a "_children" field might work.
I am having difficulty figuring out where to get started.
Ultimately, I need to have the parent-to-child relationship represented in the CSV data with a value in a parent ID field in the child rows (this field can be blank in the top-level parent rows because they have no parent). I think I would need to include an ID and ParentID in the data table to achieve this, and perhaps enforce the validation of that key using some additional functions as data is inserted into the table.

Answer 1

Below is currently how I am exporting nested data tables to CSV. This will insert a new column at the end to include a parent row identifier of your choice. It would be easy to take that out or make it conditional if you do not need it.
// Export CSV file to download
$("#export-csv").click(function(){
table.download(dataTreeCSVfileFormatter, "data.csv",{nested:true, nestedParentTitle:"Parent Name", nestedParentField:"name"});
});
// Modified CSV file formatter for nested data trees
// This is a copy of the CSV formatter in modules/download.js
// with additions to recursively loop through children arrays and add a Parent identifier column
// options: nested:true, nestedParentTitle:"Parent Name", nestedParentField:"name"
var dataTreeCSVfileFormatter = function(columns, data, options, setFileContents, config){
//columns - column definition array for table (with columns in current visible order);
//data - currently displayed table data
//options - the options object passed from the download function
//setFileContents - function to call to pass the formatted data to the downloader
var self = this,
titles = [],
fields = [],
delimiter = options && options.delimiter ? options.delimiter : ",",
nestedParentTitle = options && options.nestedParentTitle ? options.nestedParentTitle : "Parent",
nestedParentField = options && options.nestedParentField ? options.nestedParentField : "id",
fileContents,
output;
//build column headers
function parseSimpleTitles() {
columns.forEach(function (column) {
titles.push('"' + String(column.title).split('"').join('""') + '"');
fields.push(column.field);
});
if(options.nested) {
titles.push('"' + String(nestedParentTitle) + '"');
}
}
function parseColumnGroup(column, level) {
if (column.subGroups) {
column.subGroups.forEach(function (subGroup) {
parseColumnGroup(subGroup, level + 1);
});
} else {
titles.push('"' + String(column.title).split('"').join('""') + '"');
fields.push(column.definition.field);
}
}
if (config.columnGroups) {
console.warn("Download Warning - CSV downloader cannot process column groups");
columns.forEach(function (column) {
parseColumnGroup(column, 0);
});
} else {
parseSimpleTitles();
}
//generate header row
fileContents = [titles.join(delimiter)];
function parseRows(data,parentValue="") {
//generate each row of the table
data.forEach(function (row) {
var rowData = [];
fields.forEach(function (field) {
var value = self.getFieldValue(field, row);
switch (typeof value === "undefined" ? "undefined" : _typeof(value)) {
case "object":
value = JSON.stringify(value);
break;
case "undefined":
case "null":
value = "";
break;
default:
value = value;
}
//escape quotation marks
rowData.push('"' + String(value).split('"').join('""') + '"');
});
if(options.nested) {
rowData.push('"' + String(parentValue).split('"').join('""') + '"');
}
fileContents.push(rowData.join(delimiter));
if(options.nested) {
if(row._children) {
parseRows(row._children, self.getFieldValue(nestedParentField, row));
}
}
});
}
function parseGroup(group) {
if (group.subGroups) {
group.subGroups.forEach(function (subGroup) {
parseGroup(subGroup);
});
} else {
parseRows(group.rows);
}
}
if (config.columnCalcs) {
console.warn("Download Warning - CSV downloader cannot process column calculations");
data = data.data;
}
if (config.rowGroups) {
console.warn("Download Warning - CSV downloader cannot process row groups");
data.forEach(function (group) {
parseGroup(group);
});
} else {
parseRows(data);
}
output = fileContents.join("\n");
if (options.bom) {
output = "\uFEFF" + output;
}
setFileContents(output, "text/csv");
};

Answer 2

as of version 4.2 it is currently not possible to include tree data in downloads, this will be comming in a later release