Lua

Extract data:image/png;base64 from HTML

See more Base64 Examples

Demonstrates how to extract base64 image data from HTMl and save to files. Lua

local chilkat = require("chilkat")

local sb = chilkat.StringBuilder.new()
local bd = chilkat.BinData.new()
local sbFilename = chilkat.StringBuilder.new()
local index = 1

local success = sb:load_file("qa_data/html/oresp body.txt", "utf-8")
-- Assume success.
print("length = " .. sb.length)

local mayHaveMore = true
while mayHaveMore do
    -- Get the base64 between the 1st occurrence "data:image/png;base64," and "'"
    local sBase64 = sb:get_between("data:image/png;base64,", "'")

    -- If nothing is found, then we'll exit the loop because there are no more.
    mayHaveMore = sb.last_method_success

    if sb.last_method_success then
        -- Found something.
        -- Load into bd and save.
        success = bd:load_encoded(sBase64, "base64")

        sbFilename:set_string("qa_output/png_")
        sbFilename:append_int(index)
        sbFilename:append(".png")

        bd:write_file(sbFilename:get_as_string())

        -- Replace "data:image/png;base64" with "data:image-png;base64" so the next iteration finds the next occurrence.
        sb:replace_first("data:image/png;base64", "data:image-png;base64")
    end

    index = index + 1
end

-- Restore our replacements..
local count = sb:replace("data:image-png;base64", "data:image/png;base64")

print("All done.")