Feature: Add support for footer row

README.md

@@ -34,5 +34,6 @@ resources:
   * [Formatting with CSS](https://github.com/custom-cards/flex-table-card/tree/master/docs/example-cfg-css.md)
   * [Auto Entities](https://github.com/custom-cards/flex-table-card/tree/master/docs/example-cfg-autoentities.md)
   * [Loading from Services](https://github.com/custom-cards/flex-table-card/tree/master/docs/example-cfg-services.md)
+  * [Adding a Summary Footer](https://github.com/custom-cards/flex-table-card/tree/master/docs/example-cfg-footers.md)
 * [Configuration Reference](https://github.com/custom-cards/flex-table-card/tree/master/docs/config-ref.md)
 * [How to Contribute](https://github.com/custom-cards/flex-table-card/tree/master/docs/contribute.md)

docs/config-ref.md

@@ -21,6 +21,7 @@ Flex Table gives you the possibility to visualize any tabular data within Lovela
 | `max_rows`             | int             |   optional    | Restrict the number of (shown) rows to this maximum number
 | `clickable`            | boolean         |   optional    | Activates the entities' on-click popup dialog
 | `auto_format`          | boolean         |   optional    | Format state and attribute data using display precision and unit of measurement, if applicable (default: `false`)
+| `display_footer`       | boolean         |   optional    | Display additional summary row at end for column totals, averages, etc. (default: `false`, see column options below)
 | `css`                  | section         |   optional    | Modify the CSS-style of this flex-table instance [(css example)](https://github.com/custom-cards/flex-table-card/blob/master/docs/example-cfg-css.md)
 | `- ...`                | item(s)         |   optional    | 
 | `entities`             | section         | **required**  | Section defining the entities, either as the *data sources* or for use by a service (see below). If no entities are required for a service, use [] and omit `include/exclude`
@@ -84,11 +85,15 @@ definition. Apart from `sort_by` no other option requires referencing of this id
 | `multi_delimiter`      | string   |   optional    | defaults to ' ', concat multiple selector-data using this string
 | `fmt`                  | string   |   optional    | format using predefined 'formatters'
 | `sort_unmodified`      | boolean  |   optional    | Sort using original value before `modify` option, if any, is applied (default: `false`)
+| `footer_type`          | string   |   optional    | Used with `display_footer`, one of `sum`, `average`, `count`, `max`, `min`, or `text`
+| `footer_text`          | string   |   optional    | Used with `display_footer`, text to be dispayed in this and optionally across several more columns (see `footer_colspan`)
+| `footer_colspan`       | string   |   optional    | Used with `display_footer` and `footer_text`, displays text across specified number of columns
+| `footer_modify`        | string   |   optional*   | Used with `display_footer`, performs same function as `modify` but for summary row only
 
 <!--|&nbsp;&lt;content&gt; |          | **required**  | see in `column contents` below, one of those must exist! -->
 
-*Use `modify` with _caution_ and on your own risk only. This will directly execute code using `eval()`, which is by definition a safety risk. Especially avoid processing any third party APIs / contents with `flex-table-card` using the `modify` parameter, *only apply this parameter, if you are 100% sure about the contents and origin of the data.* 
-Apart from that `modify` is very powerful, see [advanced cell formatting](https://github.com/custom-cards/flex-table-card/blob/master/docs/example-cfg-advanced-cell-formatting.md).
+*Use `modify` and `footer_modify` with _caution_ and at your own risk only. This will directly execute code using `eval()`, which is by definition a safety risk. Especially avoid processing any third party APIs / contents with `flex-table-card` using the `modify` or `footer_modify` parameters, *only apply these parameters if you are 100% sure about the contents and origin of the data.* 
+Apart from that `modify` and `footer_modify` are very powerful, see [advanced cell formatting](https://github.com/custom-cards/flex-table-card/blob/master/docs/example-cfg-advanced-cell-formatting.md).
 
 
 ### Currently the available *formatters are: 

docs/example-cfg-data.md

@@ -10,6 +10,8 @@ for the assigned value of `data`:
 * `name` = *friendliest name* will be selected
 * `object_id` = full entity *path* without domain
 * `icon` = renders the entity's current icon (`entity.attributes.icon`) into the cell
+* `device` = name of the device that the entity belongs to, if available
+* `area` = name of the area that the entity or its device is assigned to, if available
 * `_state`= is a *hack* to be able to select `entity.attributes.state` as data
 * any `key in this.entity` (e.g., `entity_id`, `state`, ...)
 * otherwise a key within `this.entity.attributes` will be assumed 
@@ -28,6 +30,8 @@ for being an `Array.isArray()`).
 each one using a comma `,`. If multiple selectors are used the resulting data is concatenated using 
 `multi_delimiter`, which defaults to a whitespace ' '.
 
+Note that even if a `device` or an `area` is defined for an `entity`, it may not be available for `flex-table` to display.
+
 ### Migration from versions < 0.7
 Since version 0.7 the old selectors (`attr`, `prop`, `attr_as_list`, `multi`) are all replaced by
 `data`, which is a don't care & drop-in replacement for the old selectors. In particular `attr`, 

docs/example-cfg-footers.md

@@ -0,0 +1,126 @@
+# Examples - Summary Footer
+
+## Adding a summary footer row to a table
+<!-- [full text section] -->
+
+To display a summary footer row below the data rows of a table, add this line to the `custom:flex-table-card` config:
+
+<!-- [listing section] -->
+``` yaml
+display_footer: true
+```
+Next, use `footer_type` to identify the columns which will display summary information. A column can be summarized using any of the following values for `footer_type`:
+
+* sum (total of numbers in column)
+* average (average of numbers in column)
+* count (count of rows)
+* max (largest number in column)
+* min (smallest number in column)
+* text (custom text)
+
+For example, to show totals for a column of numbers:
+
+``` yaml
+  - name: Value
+    data: value
+    footer_type: sum
+```
+
+### Cells included in summary
+
+Only cells with values that can be interpreted as numbers will be included in the summary when using `sum`, `average`, `max`, or `min`. (`count` always counts all rows.)
+The number can have leading and trailing spaces, and any number of trailing non-numeric characters, but only the column `prefix` plus _one_ leading non-numeric character, 
+such as a currency sign. Otherwise it will be ignored.
+
+### Formatting values
+
+The formatting options `align`, `prefix`, and `suffix` (but not `modify`) will also apply to the summary row.
+Use `footer_modify` to apply any special formatting to any `footer_type`. As summary values are not associated with a single entity or entity attribute, 
+`auto_format` cannot be used to format them.
+
+A good use of `footer_modify` is to limit the number of decimal places shown by using the `toFixed` method:
+
+``` yaml
+    footer_modify: x.toFixed(2)
+```
+
+### Using CSS
+
+The default formatting of the row displays a solid line above and below the row:
+
+``` yaml
+"tfoot *": "border-style: solid none solid none;"
+```
+
+This can be overridden using the `css` option in the config. Available CSS selectors under `tfoot` are `tr`, `th`, and `td`. Also available are `ID` selectors of the form `'#tfootcol<n>'`,
+where `<n>` is the column number, beginning with 0. Only non-hidden columns are counted.
+
+### Displaying text
+
+To display text in one or more columns, use `footer_type: text` and `footer_text: <the text>`. Use `footer_colspan` to span more than one column. For example:
+
+``` yaml
+  - name: Country
+    data: countries
+    footer_type: text
+    footer_text: 'Total Value: '
+    footer_colspan: 2
+```
+
+Note that the text "Total Value" has no conceptual relationship to the columns it is under, a list of countries and whatever is in the next column in this example. 
+This is simply the first of two columns where the text will be displayed, with the expectation that the following column will contain a sum of values.
+
+### Complete example
+
+The following is a complete example card that demonstrates the use of footer options.
+
+``` yaml
+type: custom:flex-table-card
+title: Bottles per Country
+service: wine_cellar.get_countries
+entities:
+  include: sensor.member_wine_inventory
+sort_by: Country-
+display_footer: true
+columns:
+  - name: Country
+    data: countries
+    modify: x.Country
+    footer_type: text
+    footer_text: 'Grand Total Value: '
+    footer_colspan: 2
+  - name: Percentage
+    data: countries
+    modify: x.percent
+    align: right
+    suffix: '%'
+  - name: Total Value
+    data: countries
+    modify: (x.value_total + '.00')
+    align: right
+    prefix: '$'
+    footer_type: sum
+    footer_modify: x.toFixed(0)
+  - name: Average Value
+    data: countries
+    modify: x.value_avg
+    align: right
+    prefix: $
+    footer_type: text
+    footer_text: 'Total Bottles: '
+  - name: Bottles
+    data: countries
+    modify: x.count
+    align: right
+    footer_type: sum
+css:
+  tfoot th: 'text-align: right;background-color: midnightblue;'
+  '#tfootcol4': 'background-color: red'
+  tfoot *: 'border-style: dotted none solid none;'
+```
+
+<!-- [example image section] -->
+<img src="../images/FlexTableFooterExample.png" alt="Summary Footer Example" width="500px">
+
+
+[Return to main README.md](../README.md)

flex-table-card.js

@@ -287,6 +287,12 @@ class DataRow {
                         // 'icon' will show the entity's default icon
                         let _icon = this.entity.attributes.icon;
                         raw_content.push(`<ha-icon id="icon" icon="${_icon}"></ha-icon>`);
+                    } else if (col_key === "area") {
+                        // 'area' will show the entity's or its device's assigned area, if any
+                        raw_content.push(this._get_area_name(this.entity.entity_id, hass));
+                    } else if (col_key === "device") {
+                        // 'device' will show the entity's device name, if any
+                        raw_content.push(this._get_device_name(this.entity.entity_id, hass));
                     } else if (col_key === "state" && config.auto_format && !col.no_auto_format) {
                         // format entity state
                         raw_content.push(hass.formatEntityState(this.entity));
@@ -394,14 +400,33 @@ class DataRow {
         return null;
     }
 
+    _get_device_name(entity_id, hass) {
+        var device_id;
+        if (hass.entities[entity_id] !== undefined) {
+            device_id = hass.entities[entity_id].device_id;
+        }
+        return device_id === undefined ? "-" : hass.devices[device_id].name_by_user || hass.devices[device_id].name;
+    }
+
+    _get_area_name(entity_id, hass) {
+        var area_id;
+        if (hass.entities[entity_id] !== undefined) {
+            area_id = hass.entities[entity_id].area_id;
+            if (area_id === undefined) {
+                let device_id = hass.entities[entity_id].device_id;
+                if (device_id !== undefined) area_id = hass.devices[device_id].area_id;
+            }
+        }
+        return area_id === undefined || hass.areas[area_id] === undefined ? "-" : hass.areas[area_id].name;
+    }
+
     render_data(col_cfgs) {
         // apply passed "modify" configuration setting by using eval()
         // assuming the data is available inside the function as "x"
         this.data = this.raw_data.map((raw, idx) => {
             let x = raw;
             let cfg = col_cfgs[idx];
-
-						let fmt = new CellFormatters();
+			let fmt = new CellFormatters();
             if (cfg.fmt) {
                 x = fmt[cfg.fmt](x);
                 if (fmt.failed)
@@ -535,7 +560,8 @@ class FlexTableCard extends HTMLElement {
                                         "text-decoration: underline; ",
             "tbody tr:nth-child(odd)":  "background-color: var(--table-row-background-color); ",
             "tbody tr:nth-child(even)": "background-color: var(--table-row-alternative-background-color); ",
-            "th ha-icon":               "height: 1em; vertical-align: top; "
+            "th ha-icon":               "height: 1em; vertical-align: top; ",
+            "tfoot *":                  "border-style: solid none solid none;"
         }
         // apply CSS-styles from configuration
         // ("+" suffix to key means "append" instead of replace)
@@ -564,7 +590,7 @@ class FlexTableCard extends HTMLElement {
         }));
 
 
-        // table skeleton, body identified with: 'flextbl'
+        // table skeleton, body identified with: 'flextbl', footer with 'flexfoot'
         content.innerHTML = `
                 <table>
                     <thead>
@@ -574,6 +600,7 @@ class FlexTableCard extends HTMLElement {
                         </tr>
                     </thead>
                     <tbody id='flextbl'></tbody>
+                    <tfoot id='flexfoot'></tfoot>
                 </table>
                 `;
         // push css-style & table as content into the card's DOM tree
@@ -632,6 +659,118 @@ class FlexTableCard extends HTMLElement {
         });
     }
 
+    _updateFooter(footer, config, rows) {
+        var innerHTML = '<tr>';
+        var colnum = -1;
+        var raw = "";
+        var colspan_remainder = 0
+
+        config.columns.map((col, idx) => {
+            if (!col.hidden) {
+                colnum++;
+                if (colspan_remainder > 0)
+                    // Skip column if previous colspan would overlap it
+                    colspan_remainder--;
+                else {
+                    var cfg = config.columns[idx];
+                    if (col.footer_type) {
+                        switch (col.footer_type) {
+                            case 'sum':
+                                raw = this._sumColumn(rows, colnum);
+                                break;
+                            case 'average':
+                                raw = this._avgColumn(rows, colnum);
+                                break;
+                            case 'count':
+                                raw = rows.length;
+                                break;
+                            case 'max':
+                                raw = this._maxColumn(rows, colnum);
+                                break;
+                            case 'min':
+                                raw = this._minColumn(rows, colnum);
+                                break;
+                            case 'text':
+                                raw = col.footer_text;
+                                break;
+                            default:
+                                console.log("Invalid footer_type: ", col.footer_type);
+                        }
+                        let x = raw;
+                        let value = cfg.footer_modify ? eval(cfg.footer_modify) : x;
+                        if (col.footer_type == 'text') {
+                            let colspan = cfg.footer_colspan ? cfg.footer_colspan : 1;
+                            innerHTML += `<th id="tfootcol${colnum}" colspan=${colspan}>${value}</th>`;
+                            colspan_remainder = colspan - 1;
+                        }
+                        else
+                            innerHTML += `<td id="tfootcol${colnum}" class="${cfg.align || ""}">${cfg.prefix || ""}${value}${cfg.suffix || ""}</td>`;
+                    }
+                    else {
+                        innerHTML += '<td></td>'
+                    }
+                }
+            }
+        });
+
+        innerHTML += '</tr>';
+        footer.innerHTML = innerHTML;
+    }
+
+    _sumColumn(rows, colnum) {
+        var sum = 0;
+        for (var i = 0; i < rows.length; i++) {
+            let cellValue = this._findNumber(rows[i].data[colnum].sort_unmodified ? rows[i].data[colnum].raw_content : rows[i].data[colnum].content);
+            if (!Number.isNaN(cellValue)) sum += cellValue;
+        }
+        return sum;
+    }
+
+    _avgColumn(rows, colnum) {
+        var sum = 0;
+        var count = 0;
+        for (var i = 0; i < rows.length; i++) {
+            let cellValue = this._findNumber(rows[i].data[colnum].sort_unmodified ? rows[i].data[colnum].raw_content : rows[i].data[colnum].content);
+            if (!Number.isNaN(cellValue)) {
+                sum += cellValue;
+                count++;
+            }
+        }
+        return sum / count;
+    }
+
+    _maxColumn(rows, colnum) {
+        var max = Number.MIN_VALUE;
+        for (var i = 0; i < rows.length; i++) {
+            let cellValue = this._findNumber(rows[i].data[colnum].sort_unmodified ? rows[i].data[colnum].raw_content : rows[i].data[colnum].content);
+            if (!Number.isNaN(cellValue)) {
+                if (cellValue > max) max = cellValue;
+            }
+        }
+        return max == Number.MIN_VALUE ? Number.NaN : max;
+    }
+
+    _minColumn(rows, colnum) {
+        var min = Number.MAX_VALUE;
+        for (var i = 0; i < rows.length; i++) {
+            let cellValue = this._findNumber(rows[i].data[colnum].sort_unmodified ? rows[i].data[colnum].raw_content : rows[i].data[colnum].content);
+            if (!Number.isNaN(cellValue)) {
+                if (cellValue < min) min = cellValue;
+            }
+        }
+        return min == Number.MAX_VALUE ? Number.NaN : min;
+    }
+
+    // Trim whitespace and leading non-numeric, but not minus sign
+    _findNumber(val) {
+        if (typeof val === "number") {
+            return val;
+        }
+        else {
+            let value = val.trim();
+            return (Number.isNaN(parseFloat(value[0])) && value[0] !== '-') ? parseFloat(value.substring(1)) : parseFloat(value);
+        }
+    }
     set hass(hass) {
         const config = this._config;
         const root = this.shadowRoot;
@@ -712,7 +851,9 @@ class FlexTableCard extends HTMLElement {
         // finally set card height and insert card
         this._setCardSize(this.tbl.rows.length);
         // all preprocessing / rendering will be done here inside DataTable::get_rows()
-        this._updateContent(root.getElementById('flextbl'), this.tbl.get_rows());
+        let data_rows = this.tbl.get_rows();
+        this._updateContent(root.getElementById('flextbl'), data_rows);
+        if (config.display_footer) this._updateFooter(root.getElementById("flexfoot"), config, data_rows);
     }
 
     _setCardSize(num_rows) {