How to pad a dataset

Sometimes when constructing a dataset in the Web Scraper more values are added into one column than another. In the example below after the first page is scraped the name John is added to the Name column along with three colors and on the next page the name David is added with along with another two colors. To give the following dataset.

Name	Color
John	Yellow
David	Red
	Green
	Blue
	Purple

However this table is misleading as it doesn't show which name was found with which colors. Instead the pad method can be used to automatically append empty cells to the end of the dataset columns until all columns are the same length. An example of the pad method being used is shown below.

Data.save(Page.getTagValue({"class":{"equals":"Name"}}), 'Name', 'Color');
Data.save(Page.getTagValues({"class":{"equals":"Color"}}), 'Name', 'Color');
Data.pad();

These scrape instructions produce a dataset which looks like this.

Name	Color
John	Yellow
	Red
	Green
David	Blue
	Purple

We could improve this further by specifiying the padValue parameter of the pad method to be the name found by the scraper. As in this example there is only ever one name per page the scrape instructions becomes.

var name = Page.getTagValue({"class":{"equals":"Name"}});
Data.save(name, 'Name', 'Color');
Data.save(Page.getTagValues({"class":{"equals":"Color"}}), 'Name', 'Color');
Data.pad(name);

Which puts a name in every empty cell of the name column as shown below.

Name	Color
John	Yellow
John	Red
John	Green
David	Blue
David	Purple