Every manipulation can target a placeholder. In that case, TwicPics will compute the final dimensions consequential to the transformations then respond with an svg image of these dimensions that also displays said dimensions.
A placeholder follows the following syntax:
Specifying the dimensions of a placeholder is optional. Syntax is
height are strictly positive numbers.
It is perfectly valid to create a placeholder with dimensions and no color. In that case, the default colors will be used.
Keep in mind the final dimensions of a placeholder depends on the transformations applied to it. So
resize=(1/10)s/placeholder:auto will give a placeholder which dimensions are 192 per 108, a tenth of the default ones.
Specifying the colors of a placeholder is mandatory unless dimensions have been specified. Syntax is
background are color expressions to be used for the text and the background of the image respectively.
autoas the color expression and TwicPics will default to an unobtrusive gray color scheme.
One nifty usage of placeholders is with the TwicPics Script.
Simply target a placeholder expression with your data-twic-src to instantly get the best suited physical size of the image and it takes the device DPR into account to boot!
The 200 pixels wide 200 pixels high image below uses this technique: