Data classification

The second part of the data conversion is to classify the data types. When the user has done this we know which columns contain URI's and which columns contain literal values.

Use Cases

• As a user, I want to be able to assign classes to my data in order to let the computer know what we are 'talking' about.
• As a user, I want to specify a base URI if my data doesn't contain URI's yet in order to create valid Linked Data.
• As a user, I want to use common vocabularies to classify my columns in order to create better linkable data.
• As a user, I want a way to undo my classification if I made an error.

Rules

• A Literal cannot have a base URI or a type
• When a base-URI is specified a new column of data needs to created containing these URI's
• At least one column must be classified as a URI before the user is able to continue

Structure

This component exists of three components

• Interaction bar
• Table representation
• Classification Dialog

Interaction bar

The interactions bar only contain the continue button which is by default disabled until the user has at least one URI classification.

Table representation

The table contains the following data from each row

• Column header
• First value of the column
• URI check box
• Current classification
• Base URI
• reset

The interaction the user has is to click on a URI check box. When the user clicks on it the dialog opens. When the user confirms his classification of the column the check box gets filled in and disabled. Furthermore, the reset button appears. When the user clicks on the reset button the data gets reset to the original state.

Dialog

The purpose of this dialog is that the user is able to specify a base URI and a classification for a column. The dialog exists of two steps. In the first step, the user is able to specify a Base URI. When the Base URI field is filled in, new columns will be created with the URI-data.
The second step forces the user to pick a classification from the vocabulary library. The user types a search-term which when hitting enter or clicking the search button will fire a query to the API. The user then gets a maximum of ten options. After that, the user is able to commit the classification and the dialog closes.

Data

This component requires only some data from the previous step. In order to create the structure needed the application uses the following function in the Data creation

  setData(data, filename) {
    let dataClassifications; // Create an empty object
    if (data.length > 1) { // If there is data
      dataClassifications = data[0].map((column, index) => ({ // For each column header (first row of data)
        columnName: column, // Name it after the first value in the column
        exampleValue: data[1][index], // Set the actual first value (second row)
        class: { name: 'Literal' }, // Everything is literal by default. 
        uri: false, // See above 
      }));
    } else { // If no data was found
      dataClassifications = []; // There are no values examlevalues
    }
    this.setState({// Update the state
      data,
      dataClassifications,
      filename,
    });
  }

Design

Default screen

Dialog

Variables

name	type	required	description
data	Array	✔️	An array of data descriptions objects as seen in the code example above
setClass	function	✔️	function called with the column index and the new class object of this column
setURI	function	✔️	function called with the column index and the new state of the URI flag of the data-object
setBaseUri	function	✔️	function called with the column index and the new base-URI of the object
nextPage	function	✔️	A Callback function which is called when a user clicks on continue