SVGChrt

The easiest way to put together a data visualisation in SVG.

Installation

npm install svgchrt

<script src="https://unpkg.com/svgchrt"></script>

Usage

const SVGChrt = require('svgchrt');

const options = {}; // How you want the visualisation to look

const Chart =  new SVGChrt(options);

Chart.plot = function() {
  /* Remember, this only provides an area
  *  to display your visualisation without
  *  having it clash with titles, subtitles
  *  or your legend. It also easily generates
  *  the legend for you. The flipside of this
  *  is that this then allows you to do
  *  whatever you want with your plot and use
  *  whichever library you see fit.
  */
};

// Get the chartable area for use in your plot function

Chart.getChartArea();

/* Returns an object with height (number),
*  points (object) and width (number).
*  Points contains x1 (the x-coordinate of
*  the leftmost points), y1 (the y-coordinate
*  of the uppermost points), x2 (the
*  x-coordinate of the rightmost points) and
*  y2 (the y-coordinate of the lowermost points).
*/

Chart.render();

Reference

Available options:

1. background (boolean), default: true

   Decides whether or not to give your chart a background to make it stand out from the page. If set to true it will provide a <rect> element with the class of chart-background for styling with CSS, and its height and width attributes will match those of the parent <svg>.

2. canvas (object)

   Contains 4 items:

   1. height (integer), default: 500

      Determines the height of your visualisation in pixels.

   2. padding (object)

      Contains 4 items: top, right, bottom and left, each of which defaults to 10 and provides an inner padding so that your visualisation is not squashed up to the edge of the SVG.

   3. viewBox (string), default: '0 0 960 500'

      Determines the viewBox of your <svg> and should usually match 0 0 width height.

   4. width (integer), default: 960

      Determines the width of your visualisation in pixels.

3. chart (object)

   Contains 1 item:

   1. margin (object)

      Contains 4 items: top, right, bottom and left, each of which defaults to 10 and provides a margin around your visualisation so that it can be visually separate from the rest of the elements.

4. description (string), default: ''

   Provides a description of your visualisation to assistive technologies such as screen readers.

5. id (string), defaut: ''

   Adds an ID to the parent SVG. It is strongly recommended to include an ID

6. legend (object)

   If the legend is set to display, then it will build and display the legend on your chart as determined by the below options. It will add a <g> element with the id and the class legend, containing a list of <g> elements with the class legend-item. Each of these g.legenditems contains a shape (<rect> is the default) with the class legend-item-icon, dependent on the options, and a <text> element with the class legend-item-text.

   Contains 12 items:

   1. background (object)

      Contains 5 items:

      1. colour (string), default: white

         Applies a fill colour to the background <rect> element.

      2. display (boolean), default: false

         Decides whether or not to add a background to the legend. If it is set to true it will add a <rect> element with the class legend-background for styling with CSS.

      3. r (number), default: 0

         Applies an even radius to the corners of the background <rect>.

      4. rx (number), default: 0

         Applies an x-radius to the corners of the background <rect>.

      5. ry (number), default: 0

         Applies a y-radius to the corners of the background <rect>.

   2. displaceTitle (boolean), default: false

      Decides whether the placement of the legend should have an effect on the positioning of the title and subtitle. If it set to true then if options.legend.position is set to top-left, left, bottom-left, top-right, right or bottom-right and the options.legend.orientation is set to vertical then the title and subtitle will shift (and possibly wrap) into their new smaller container.

      If options.legend.position is set to top or bottom or options.legend.orientation is set to horizontal then this option is ignored and treated as false.

   3. display (boolean), default: false

      Decides whether or not to display the legend.

   4. icons (object)

      Provides a default for the icons contained in each legend item.

      Contains 9 items:

      1. cx (integer), default: 7

         Determines the x-coordinate of the centre of the icons (relative to the legend item's co-ordinate space).

         N.B. The cx property is only applicable to certain SVG elements, the <circle> and the <ellipse>.

      2. cy (integer), default: 7

         Determines the y-coordinate of the centre of the icons (relative to the legend item's co-ordinate space).

         N.B. The cy property is only applicable to certain SVG elements, the <circle> and the <ellipse>.

      3. d (string), default: ''

         For <path> elements, determines the shape of the path.

      4. display (boolean), default: false

         Determines whether to display an icon.

      5. height (integer), default: 14

         Determines the height of the icons in pixels.

         N.B. The height property is only applicable to certain SVG elements, in this case the shape beneath this defaults to rect which takes a height property.

      6. r (integer), default: 7

         Determines the radius of the icons.

         N.B. The r property is only applicable to the <circle>.

      7. rx (integer), default: 7

         Determines the x-radius of the icons.

         N.B. The rx property is only applicable to the <ellipse>.

      8. ry (integer), default: 7

         Determines the y-radius of the icons.

         N.B. The ry property is only applicable to the <ellipse>.

      9. shape (string), default: 'rect'

         Determines the shape that the icons should take.

      10. width (integer), default: 14

          Determines the width of the icons in pixels.

          N.B. The width property is only applicable to certain SVG elements, in this case the shape above this defaults to rect which takes a width property.

   5. itemMargin (object)

      Contains 4 items: top, right, bottom and left, each of which defaults to 5 and provides a margin between each legend item to allow them to be visually separate from each other.

   6. items (array), default: []

      An array of objects to be displayed on the legend. Each object must contain a displayName property which contains the text that will be displayed, this can either be a string or a function that returns a string. You may also want to include a class property to style the icons differently (different fill colours for example) with CSS.

      You can also include an icon property as an object, if you want to overwrite your default icon options set above.

      As you may be pulling in your legend items from a dataset containing many more properties, the library will ignore any additional properties.

      If this array is empty then the legend will not display.

   7. layOverChart (boolean), default: false

      Decides whether the legend should be displayed on top of the visualisation or resize the visualisation to fit.

   8. margin (object)

      Contains 4 items: top, right, bottom and left, each of which defaults to 10 and provides a margin around your legend so that it can be visually separate from the rest of the elements.

   9. orientation (string), default: 'vertical'

      Decides whether your legend items should stack vertically on top of one another or horizontally next to each other.

   10. padding (object)

       Contains 4 items: top, right, bottom and left, each of which defaults to 0 and provides an inner padding so that your items are not squashed up to the edge of the legend's background.

       They default to 0 as a padding is only really recommended if you set options.legend.background.display to true.

   11. position (string), default: 'right'

       Provides 8 options: top-left, top, top-right, right, bottom-right, bottom, bottom-left, left and decides where the legend should be on your SVG.

   12. title (string), default: ''

       Future update

       Adds a title to the legend and provides a <text> element with the class legend-title for styling with CSS.

7. subtitle (object)

   Contains 4 items:

   1. appendToTitle (object)

      Contains 2 items:

      1. append (boolean), default: false

         If set to true, this appends the text content of the subtitle (if there is any) to the visualisation's <title> element.

         N.B This does not do anything visually to the visualisation. It may be used to adjust what screen readers see as the title of the visualisation.

      2. join (string), default: ' - '

         If the criteria are met to append the subtitle to the title, this string will sit between them. As an example with the default string the title presented to assistive technologies would be Title - Subtitle. You should have at least a space, as an empty string will yield TitleSubtitle.

   2. display (boolean), default: false

      Determines whether to display a subtitle on the chart, if it is set to true and options.subtitle.text is not an empty string, it will provide a <text> element with the class of chart-subtitle for styling with CSS. Other attributes will be dy="1em", text-anchor="middle" and x and y which the library will calculate. Should the subtitle be too long to fit onto a single line, the <text> element will contain 2 or more <tspan> elements.

   3. margin (object)

      Contains 4 items: top, right, bottom and left, each of which defaults to 10 and provides a margin around your subtitle so that it can be visually separate from the rest of the elements.

   4. text (string), default: ''

      Contains the text to display as the subtitle, if it is not an empty string and options.subtitle.display is set to true, it will provide a <text> element with the class of chart-subtitle for styling with CSS. Other attributes will be dy="1em", text-anchor="middle" and x and y which the library will calculate. Should the subtitle be too long to fit onto a single line, the <text> element will contain 2 or more <tspan> elements.

8. target (string), default: '' REQUIRED

   Targets the container <div> or <section> where your visualisation is to be displayed. Will throw an error is either left blank or the target element does not exist.

   Can target either an element's ID or its querySelector.

9. title (object)

   Please include a title

   Contains 3 items:

   1. display (boolean), default: false

      Determines whether to display a title on the chart, if it is set to true and options.title.text is not an empty string, it will provide a <text> element with the class of chart-title for styling with CSS. Other attributes will be dy="1em", text-anchor="middle" and x and y which the library will calculate. Should the title be too long to fit onto a single line, the <text> element will contain 2 or more <tspan> elements.

   2. margin (object)

      Contains 4 items: top, right, bottom and left, each of which defaults to 10 and provides a margin around your subtitle so that it can be visually separate from the rest of the elements.

   3. text (string), default: ''

      Contains the text to display as the title, if it is not an empty string and options.title.display is set to true, it will provide a <text> element with the class of chart-title for styling with CSS. Other attributes will be dy="1em", text-anchor="middle" and x and y which the library will calculate. Should the title be too long to fit onto a single line, the <text> element will contain 2 or more <tspan> elements.

      If it is not an empty string then, regardless of whether options.title.display is true, it will add a <title> element to your SVG to allow assistive technologies such as screenreaders to see it.