trading-chart-js/src/helpers/tmp/dc_calc_syntax2.js

Hackable charting lib for traders

/* Indicator calculation function (sketch): */

class Overlay1 {
    // ... methods:
    calc() {
        return `
            $prop('length', 25, [2, 200, 1]
            $init(() => {
                // Import indicator + set the default params
                this.ind1 = dep('SomeIndicator1', [12])

                // Import a TA library (nmp package)
                this.ta_lib = dep('@some_ta_lib')

            })
            // Explicit update otherwise there will
            // an auto-update before the current update() call
            let v0 = ind1.update(12)
            // get value of SomeIndicator1
            v5 = ind1[5]

            ta_lib.some_f()

            let sum = close[0]
            for (var i = 1; i < length; i++) {
                sum = sum + nz(close[i])
            }
            return sum / length // Returns the last value
        }
    `
}

class Overlay2 {
    // ... methods:
    calc() {
        return `
            $prop('length', 25, [2, 200, 1]
            // Assuming this is an overlay without draw(),
            // so we can specify an overlay for rendering:
            $conf('renderer', 'Spline')

            // Use update() to for the init, or just for
            // the live updates
            $conf('precalc', true)

            // Inverted buffer leng (autodetect?)
            $conf('bufflen', 200)

            // (Future feature)  Place the result on a chart's
            // view instead of the main chart
            $conf('saveAsView', 'heikin')

            $init(() => {
                // Non-inverted data array of this Overlay
                // Will be filled during the calculation
                data[0] = 1
                data[0] = 2
                // 1.5, 1.75 , ....
            })

            this[0] = (this[1] + this[2]) / 2

            // t -> current timestamp
            if (t > 1594804193000) { /* ... */ }
            return
        `
    }
}