Metadata

You can change the format and display of your chart by using the metadata key of the Matatika dataset YAML file.

The metadata key relates to how the data from the query within the dataset is displayed as an insight.

Example

metadata: |-
    {
        "name": "google_analytics_locations",
        "label": "Daily Users",
        "related_table": {
            "columns": [
                {
                    "name": "report_date",
                    "label": "Date",
                    "description": "Date"
                }
            ], 
            "aggregates": [
                {
                    "name": "total_users",
                    "label": "Total Users",
                    "description": "Total Users"
                }
            ]
        }
    }

Metadata Key	Details
`name`	Name of the sql table you are querying, or it alias if assigned.
`label`	Chart label.
`related_table`	Columns and aggregates to display in the chart.
`columns`	x-axis catagories, usually dates or groups.
`aggregates`	Bars, Points, Lines that show the information over the `columns` catagories.
`links`	Can be defined to connect datasets or external links, either by clicking on specific aggregates, or defining a link globally.

Post-processing

columns and aggregates support post-processing to modify values before they are rendered by the visualisation. This can be supplied in one of two ways:

A named post-processor: post_process
An expression: post_process_expr

When both post_process and post_process_expr are supplied for a single column or aggregate, post_process_expr will take precedence.

Named post-processors

Named post-processors are aliases for common processing methods. A named post-processor can be specified using post_process.

Name	Description
`json_parse`	Parse a JSON string

metadata: |-
    {
        "name": "test_failures",
        "label": "Test failures",
        "related_table": {
            "columns": [
                {
                    "name": "rows_json",
                    "label": "Rows JSON",
                    "post_process": "json_parse"
                }
            ]
        }
    }

Expressions

Expressions can be used to modify values with a JavaScript function that accepts a single argument as the value and returns the processed value. This function can be named (e.g. JSON.parse) or anonymous (e.g. value => value.toUpperCase()). An expression can be specified using post_process_expr.

metadata: |-
    {
        "name": "test_failures",
        "label": "Test failures",
        "related_table": {
            "columns": [
                {
                    "name": "rows_json",
                    "label": "Rows JSON",
                    "post_process_expr": "JSON.parse"
                }
            ]
        }
    }

Examples of Links

Global Link Example (Dataset)

With a global link, if you click on any of the data in the visualisation you have to option of viewing what is linked. You can use a global link to drill-down to another dataset, or link to an external source.

metadata: |-
    {
        "name": "google_analytics_locations",
        "label": "Daily Users",
        "related_table": {
        "columns": [
            {"name": "report_date", "label": "Date", "description": "Date"}
        ], 
        "aggregates": [
            {"name": "total_users", "label": "Total Users", "description": "Total Users"}
        ]
        },
        "links": [{"dataset": "another_datasets_file_name_without_file_extension"}]
    }

Aggregate Link Example (External Link)

With an aggregate link, if you click on the specific aggregate data in the visualisation you have to option of viewing what is linked. You can use a aggregate link to drill-down to another dataset, or link to an external source.

metadata: |-
    {
        "name": "google_analytics_locations",
        "label": "Daily Users",
        "related_table": {
        "columns": [
            {"name": "report_date", "label": "Date", "description": "Date"}
        ], 
        "aggregates": [
            {"name": "total_users", "label": "Total Users", "description": "Total Users", "links": [
                    {"href": "https://developers.google.com/analytics", "target": "_blank"}]
            }
        ]
        }
    }