Скачать или смотреть Understanding Why stroke-dasharray May Not Work with Some Polygons in SVG

This guide dives into the mechanics of why `stroke-dasharray` doesn't always create dashed lines for polygons in SVG. Learn how to achieve dotted effects effectively with clear examples and alternatives.
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Understanding Why stroke-dasharray May Not Work with Some Polygons in SVG

When working with SVG (Scalable Vector Graphics), you might encounter instances where the stroke-dasharray property does not apply as expected to certain polygons. Specifically, you may find that while trying to render a dotted line for shapes like polygons with fewer points, the desired effect does not occur. In this guide, we'll explore the reason behind this behavior and provide solid solutions.

The Problem: Dotted Lines Not Rendering as Expected

Consider this scenario: You define a polygon in SVG with two points, like points A and B. You want to apply a dashed line effect using the stroke-dasharray attribute. However, when rendering, the lines do not appear dotted. They often just render as solid lines.

Sample SVG Code

[[See Video to Reveal this Text or Code Snippet]]

The Explanation: Closing the Polygon Path

When you define a polygon with two points, SVG automatically closes the shape by drawing a line from point B back to point A. This behavior creates an overlap: the stroke for the closing line can obscure the gaps created by stroke-dasharray. Consequently, if the solid line overlaps where the gap is supposed to be, it may become invisible.

Key Points:

Polygon automatically closes shapes, leading to overlapping strokes.

The overlap can cause the gaps defined by stroke-dasharray to "disappear".

The effect depends on the total length of the line relative to the defined dash array.

The Solution: Switching to Path or Polyline

To effectively utilize stroke-dasharray without unexpected results, consider alternative SVG elements like <path> or <polyline>.

Using <path> Element

Switching from a polygon to a path allows more precise control over the drawing without closing the shape back to the start point. Here’s how you can utilize the <path> element effectively:

[[See Video to Reveal this Text or Code Snippet]]

Benefits of Using <polyline>

Alternatively, if you only need to create straight lines without closing them, consider using the <polyline> element. The <polyline> element does not return to the starting point, avoiding the overlap issue. Here’s an example of how you can implement it:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

In summary, when working with SVG polygons, it's essential to remember that a polygon's inherent behavior of closing shapes can affect how stroke-dasharray renders. By either switching to a <path> or using a <polyline>, you can achieve the desired dashed effect without encountering the overlap issues that lead to solid lines.

This adjustment will provide you with better control over your graphical designs in SVG and ensure that your work appears precisely how you intend.