html2pdf.go

package gorestpack

import (
	"bytes"
	"errors"
	"io"

	"github.com/eknkc/request"
)

// Create a new Screenshot Client with supplied restpack.io access key
func NewHTMLToPDFClient(accessToken string) HTMLToPDFClient {
	return &htmlToPDFClient{
		client: &client{
			httpClient:  request.New(),
			accessToken: accessToken,
			basePath:    "https://restpack.io/api/html2pdf/v5",
		},
	}
}

// Options supplied to the Restpack Screenshot API for conversion
type HTMLToPDFCaptureOptions struct {
	// Custom page size for created document
	PDFPage string `json:"pdf_page,omitempty"`
	// CSS style margin sizes.
	PDFMargins string `json:"pdf_margins,omitempty"`
	// Page Orientation
	PDFOrientation string `json:"pdf_orientation,omitempty"`
	// Additional CSS string to be injected into the page before render.
	CSS string `json:"css,omitempty"`
	// Additional JS string to be injected into the page before render.
	JS string `json:"js,omitempty"`
	// Time in milliseconds to delay capture after page load
	Delay int `json:"delay,omitempty"`
	// Time in milliseconds for the resulting image to be cached for further requests.
	CacheTTL int `json:"cache_ttl,omitempty"`
	// Custom user-agent header string for the web request.
	UserAgent string `json:"user_agent,omitempty"`
	// Custom accept-language header string for the web request.
	AcceptLanguage string `json:"accept_language,omitempty"`
	// Additional headers seperated with newline
	Headers string `json:"headers,omitempty"`
	// Force CSS media emulation for print or screen.
	EmulateMedia string `json:"emulate_media,omitempty"`
	// By default, any response from remote server outside http 200-299 status codes generates an error. If you wish to capture error pages, pass true.
	AllowFailed bool `json:"allow_failed,omitempty"`
	// Wait until window load event fires or network becomes idle before capturing the page.
	Wait string `json:"wait,omitempty"`
	// Wait until a DOM element matching the provided css selector becomes present on the page.
	Shutter string `json:"shutter,omitempty"`
	// Ensure that the captured document does not get cached / stored for further use
	Privacy bool `json:"privacy,omitempty"`
	// If specified, ensures that the resulting file is saved with the given name.
	Filename string `json:"filename,omitempty"`
	//Custom pdf page width. Must be used together with PdfHeight
	PdfWidth string `json:"pdf_width,omitempty"`
	//Custom pdf page height. Check PdfWidth for details.
	PdfHeight string `json:"pdf_height,omitempty"`
	//HTML template for page header. It should have a valid markup and can contain elements with classes 'pageNumber', 'totalPages', 'url', 'title' or 'date'. Header is automatically added to all pages. Note that you need to have top margins on your documents in order to have the header show up.
	PdfHeader string `json:"pdf_header,omitempty"`
	//HTML template for page footer. Please check pdf_header information for details.
	PdfFooter string `json:"pdf_footer,omitempty"`
	//Removes the ads on the page
	BlockAds bool `json:"block_ads,omitempty"`
	//Block / hide European Union cookie warnings before capture.
	BlockCookieWarnings bool `json:"block_cookie_warnings,omitempty"`
}

type htmlToPDFCallOptions struct {
	HTMLToPDFCaptureOptions
	JSON bool   `json:"json,omitempty"`
	URL  string `json:"url,omitempty"`
	HTML string `json:"html,omitempty"`
}

// Capture result from screenshot API
type HTMLToPDFCaptureResult struct {
	Image        string `json:"image,omitempty"`
	Width        string `json:"width,omitempty"`
	Height       string `json:"height,omitempty"`
	RemoteStatus string `json:"remote_status,omitempty"`
	Cached       bool   `json:"cached,string,omitempty"`
	URL          string `json:"url,omitempty"`
}

// Restpack Screenshot API Client
type HTMLToPDFClient interface {
	// Capture a URL and return the information & cdn url
	Capture(url string, options ...HTMLToPDFCaptureOptions) (HTMLToPDFCaptureResult, error)
	// Capture a HTML snippet and return the information & cdn url
	CaptureHTML(url string, options ...HTMLToPDFCaptureOptions) (HTMLToPDFCaptureResult, error)

	// Capture a URL and return a reader for resulting pdf
	CaptureToReader(url string, options ...HTMLToPDFCaptureOptions) (io.Reader, error)
	// Capture a HTML snippet and returna a reader for resulting pdf
	CaptureHTMLToReader(url string, options ...HTMLToPDFCaptureOptions) (io.Reader, error)
}

type htmlToPDFClient struct {
	*client
}

func (me *htmlToPDFClient) Capture(url string, options ...HTMLToPDFCaptureOptions) (HTMLToPDFCaptureResult, error) {
	opt := htmlToPDFCallOptions{
		URL:  url,
		JSON: true,
	}

	if len(options) > 0 {
		opt.HTMLToPDFCaptureOptions = options[0]
	}

	var res struct {
		HTMLToPDFCaptureResult
		Error string `json:"error"`
	}
	httpres, _, err := me.do("POST", "/convert").JSON(opt).EndStruct(&res)

	if err != nil {
		return HTMLToPDFCaptureResult{}, err
	}

	if httpres.StatusCode > 300 {
		return res.HTMLToPDFCaptureResult, errors.New(res.Error)
	}

	return res.HTMLToPDFCaptureResult, err
}

func (me *htmlToPDFClient) CaptureHTML(html string, options ...HTMLToPDFCaptureOptions) (HTMLToPDFCaptureResult, error) {
	opt := htmlToPDFCallOptions{
		HTML: html,
		JSON: true,
	}

	if len(options) > 0 {
		opt.HTMLToPDFCaptureOptions = options[0]
	}

	var res struct {
		HTMLToPDFCaptureResult
		Error string `json:"error"`
	}
	httpres, _, err := me.do("POST", "/convert").JSON(opt).EndStruct(&res)

	if err != nil {
		return HTMLToPDFCaptureResult{}, err
	}

	if httpres.StatusCode > 300 {
		return res.HTMLToPDFCaptureResult, errors.New(res.Error)
	}

	return res.HTMLToPDFCaptureResult, err
}

func (me *htmlToPDFClient) CaptureToReader(url string, options ...HTMLToPDFCaptureOptions) (io.Reader, error) {
	opt := htmlToPDFCallOptions{
		URL:  url,
		JSON: false,
	}

	if len(options) > 0 {
		opt.HTMLToPDFCaptureOptions = options[0]
	}

	resp, body, err := me.do("POST", "/convert").JSON(opt).End()

	if err != nil {
		return nil, err
	}

	if resp.StatusCode > 300 {
		return nil, errors.New(resp.Status)
	}

	return bytes.NewReader(body), err
}

func (me *htmlToPDFClient) CaptureHTMLToReader(html string, options ...HTMLToPDFCaptureOptions) (io.Reader, error) {
	opt := htmlToPDFCallOptions{
		HTML: html,
		JSON: false,
	}

	if len(options) > 0 {
		opt.HTMLToPDFCaptureOptions = options[0]
	}

	resp, body, err := me.do("POST", "/convert").JSON(opt).End()

	if err != nil {
		return nil, err
	}

	if resp.StatusCode > 300 {
		return nil, errors.New(resp.Status)
	}

	return bytes.NewReader(body), err
}