HTML back-end

The following options are available when the HTML backend is used. Those can be passed as keywords when calling the function pretty_table:

  • highlighters: An instance of HTMLHighlighter or a tuple with a list of HTML highlighters (see the section HTML highlighters).
  • linebreaks: If true, then \\n will be replaced by <br>. (Default = false)
  • noheader: If true, then the header will not be printed. Notice that all keywords and parameters related to the header and sub-headers will be ignored. (Default = false)
  • nosubheader: If true, then the sub-header will not be printed, i.e. the header will contain only one line. Notice that this option has no effect if noheader = true. (Default = false)
  • standalone: If true, then a complete HTML page will be generated. Otherwise, only the content between the tags <table> and </table> will be printed (with the tags included). (Default = true)
  • tf: An instance of the structure HTMLTableFormat that defines the general format of the HTML table.

HTML highlighters

A set of highlighters can be passed as a Tuple to the highlighters keyword. Each highlighter is an instance of the structure HTMLHighlighter. It contains the following two public fields:

  • f: Function with the signature f(data,i,j) in which should return true if the element (i,j) in data must be highlighted, or false otherwise.
  • fd: Function with the signature f(h,data,i,j) in which h is the highlighter. This function must return the HTMLDecoration to be applied to the cell that must be highlighted.

The function f has the following signature:

f(data, i, j)

in which data is a reference to the data that is being printed, and i and j are the element coordinates that are being tested. If this function returns true, then the highlight style will be applied to the (i,j) element. Otherwise, the default style will be used.

If the function f returns true, then the function fd(h,data,i,j) will be called and must return an element of type HTMLDecoration that contains the decoration to be applied to the cell.

A HTML highlighter can be constructed using two helpers:

HTMLHighlighter(f::Function, decoration::HTMLDecoration)
HTMLHighlighter(f::Function, fd::Function)

The first will apply a fixed decoration to the highlighted cell specified in decoration whereas the second let the user select the desired decoration by specifying the function fd.


If only a single highlighter is wanted, then it can be passed directly to the keyword highlighter without being inside a Tuple.


If multiple highlighters are valid for the element (i,j), then the applied style will be equal to the first match considering the order in the tuple highlighters.


If the highlighters are used together with Formatters, then the change in the format will not affect the parameter data passed to the highlighter function f. It will always receive the original, unformatted value.

There are a set of pre-defined highlighters (with names hl_*) to make the usage simpler. They are defined in the file ./src/backends/html/predefined_highlighters.jl.

julia> t = 0:1:20;

julia> data = hcat(t, ones(length(t))*1, 1*t, 0.5.*t.^2);

julia> header = ["Time" "Acceleration" "Velocity" "Distance";
                  "[s]"       "[m/s²]"    "[m/s]"      "[m]"];

julia> hl_v = HTMLHighlighter( (data,i,j)->(j == 3) && data[i,3] > 9, HTMLDecoration(color = "blue", font_weight = "bold"));

julia> hl_p = HTMLHighlighter( (data,i,j)->(j == 4) && data[i,4] > 10, HTMLDecoration(color = "red"));

julia> hl_e = HTMLHighlighter( (data,i,j)->data[i,1] == 10, HTMLDecoration(background = "black", color = "white"))

julia> pretty_table(data, header, backend = :html, highlighters = (hl_e, hl_p, hl_v))

HTML table formats

The following table formats are available when using the html back-end:

tf_html_default (Default)





In this case, the table format html_matrix was printed with the option noheader = true.