vel.text(content [, opt])
Set the text content
of the element.
This only makes sense for the <text>
element.
This method can deal with multi-line text in case the content
string contains newline characters (\n
).
t.text('my text');
t.text('my multiline\ntext');
opt.lineHeight
can be optionally used to set the line height of the text.
It defaults to '1em'
. The opt.lineHeight
can also be set to 'auto'
in which case it is left on Vectorizer to set the best possible line height.
This is useful if you annotate the text making it a rich-text (see below) and you don't want to set the line height to a fixed value for all the lines.
Use opt.textVerticalAnchor
to control the y-axis alignment relatively to the initial text position.
The anchor position can be set by a keyword or a value in px
or em
.
'top'
- at the top of the text'bottom'
- at the bottom of the text'middle'
- in the middle of the text'0.3em'
- in the middle of the first line'0.8em'
- at the top edge of the first line (default)'-0.3em'
- at the bottom edge of the first line0
or '0em'
- at the baseline of the first line20
or '20px'
- 20 pixels up from the baseline of the first linet.text('my text\nwith custom line height', {
lineHeight: '2em'
});
t.attr('font-size', 20).text('vertically aligned text', {
textVerticalAnchor: 'middle'
});
Note: The method uses a heuristic algorithm to align the text.
To improve the results, define the text font-size
attribute in px
and lineHeight
option either in px
or em
.
If a keyword or annotations are used and no font-size
attribute is set on the text element, the font size defaults to 16
.
If opt.annotations
array is set, the text will be annotated by the attributes defined in the annotations array.
This means that you can easily render rich text.
Each annotation in the annotations array is an object of the form { start: Number, end: Number, attrs: Object }
where start
(inclusive) and end
(exclusive) define the range of the text content
where the attrs
SVG Attributes will be applied.
If there are overlapping annotations, they will be smartly merged (classes concatenated, attributes merged, style
can be always defined either as a string or an object).
var text = V('text', { x: 250, y: 150, fill: 'black' });
text.text('This is a rich text.\nThis text goes to multiple lines.', {
lineHeight: 'auto',
annotations: [
{ start: 5, end: 10, attrs: { fill: 'red', 'font-size': 30, rotate: '20' }},
{ start: 7, end: 15, attrs: { fill: 'blue' }},
{ start: 20, end: 30, attrs: { fill: 'blue', 'class': 'text-link', style: 'text-decoration: underline' }}
]
});
svg.append(text);
If opt.includeAnnotationIndices
is set to true
, each <tspan>
will contain the 'annotations'
attribute with comma-separated indices of annotations that apply to that piece of text.
Vectorizer provides some useful functions for working with annotations.
Those are V.findAnnotationsAtIndex(), V.findAnnotationsBetweenIndexes() V.shiftAnnotations() and V.annotateString().
To make the text go along a path, use opt.textPath
. It can be either string or an object.
The provided textPath
specifies the path data of the path the text should go along.
t.text('text that goes along a path', { textPath: 'M 0 100 Q 30 10 100 0' });
The provided textPath
can contain a d
property that specifies the path data of the path the text should go along, and optionally other attributes that will be set on the automatically created <textPath>
SVG element, such as startOffset
.
If textPath
contains xlink:href
property, an existing path is used as reference.
t.text('another text that goes along a path', {
textPath: {
d: 'M 0 100 Q 30 10 100 0',
startOffset: 50
}
});
t.text('text that goes along an existing path', {
textPath: { 'xlink:href': '#path1' }
});
By default, the SVGTextElement without the content is not displayed (It is not clickable and occupies no space). To prevent this, use opt.displayEmpty
and set it to true
.