


php Xiaobian Youzi will introduce to you a tool called Go ChromeDP, which can ignore all external and internal CSS styles during the process of printing web pages to PDF, only Use CSS styles from HTML files. This tool can help developers better control the style of PDF output and provide more flexible customization options. With Go ChromeDP, we can easily generate high-quality PDF documents that meet our needs, providing better user experience and functionality for our projects. Next, let us learn about the usage and features of Go ChromeDP!
Question content
go chromedp does not use any css, neither internal nor external styles (only styles written in html, not other files). The method I use
page.setdocumentcontent(frametree.frame.id, string(buf.bytes())).do(ctx)
Add the html file to chromedp, and
buf, _, err: = page.printtopdf().do(ctx) if err != nil { return err } _, err = outputbuf.write(buf) if err != nil { return err }
Print to pdf, but the resulting pdf has no styles (even using an external css file server). I tried adding it using page.getresourcetree().do(ctx)
css.createstylesheet(resourcetree.frame.id).do(ctx)
css.SetStyleSheetText(stylesheet, `.c { color: red; font-size: 30px; background-color: aqua; } `).Do(ctx)
It does work, but it's hard to use it every time I want to generate a pdf, especially in my case since I'm using html from html/template. Maybe there is an easy way to add external css to a single html file? what do you think?
Thank you for your answer
Bohdan
I want to use chromedp to convert a go template with external css, images and fonts to pdf, but it ignores anything outside the main html file.
Solution
Please note that loading external resources takes some time. You should wait for them to load. When the page is ready, the page.loadeventfired
event is raised. So we can wait for this event and then print the page. See demo below:
package main import ( "context" "fmt" "log" "net/http" "net/http/httptest" "os" "sync" "time" "github.com/chromedp/cdproto/page" "github.com/chromedp/chromedp" ) func main() { ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { // Simulate a network latency. time.Sleep(2 * time.Second) w.Header().Set("Content-Type", "text/css") fmt.Fprint(w, `h1 {font-size: 100pt; color: red;}`) })) defer ts.Close() ctx, cancel := chromedp.NewContext(context.Background()) defer cancel() // construct your html html := `<html> <head> <link rel="stylesheet" href="%s/style.css"> </head> <body> <h1 id="Hello-World"> Hello World! </h1> </body> </html> ` var wg sync.WaitGroup wg.Add(1) if err := chromedp.Run(ctx, chromedp.Navigate("about:blank"), // setup the listener to listen for the page.EventLoadEventFired chromedp.ActionFunc(func(ctx context.Context) error { lctx, cancel := context.WithCancel(ctx) chromedp.ListenTarget(lctx, func(ev interface{}) { if _, ok := ev.(*page.EventLoadEventFired); ok { wg.Done() // remove the event listener cancel() } }) return nil }), chromedp.ActionFunc(func(ctx context.Context) error { frameTree, err := page.GetFrameTree().Do(ctx) if err != nil { return err } return page.SetDocumentContent(frameTree.Frame.ID, fmt.Sprintf(html, ts.URL)).Do(ctx) }), // wait for page.EventLoadEventFired chromedp.ActionFunc(func(ctx context.Context) error { wg.Wait() return nil }), chromedp.ActionFunc(func(ctx context.Context) error { buf, _, err := page.PrintToPDF().Do(ctx) if err != nil { return err } return os.WriteFile("sample.pdf", buf, 0644) }), ); err != nil { log.Fatal(err) } log.Println("done!") }
Reference:https://www.php.cn/link/13c86fac19a52dbc843105b709dc71fc一个>.
The above is the detailed content of Go ChromeDP ignores any external or internal CSS during printing to pdf, only uses the CSS from the html file. For more information, please follow other related articles on the PHP Chinese website!

You should care about the "strings" package in Go because it provides tools for handling text data, splicing from basic strings to advanced regular expression matching. 1) The "strings" package provides efficient string operations, such as Join functions used to splice strings to avoid performance problems. 2) It contains advanced functions, such as the ContainsAny function, to check whether a string contains a specific character set. 3) The Replace function is used to replace substrings in a string, and attention should be paid to the replacement order and case sensitivity. 4) The Split function can split strings according to the separator and is often used for regular expression processing. 5) Performance needs to be considered when using, such as

The"encoding/binary"packageinGoisessentialforhandlingbinarydata,offeringtoolsforreadingandwritingbinarydataefficiently.1)Itsupportsbothlittle-endianandbig-endianbyteorders,crucialforcross-systemcompatibility.2)Thepackageallowsworkingwithcus

Mastering the bytes package in Go can help improve the efficiency and elegance of your code. 1) The bytes package is crucial for parsing binary data, processing network protocols, and memory management. 2) Use bytes.Buffer to gradually build byte slices. 3) The bytes package provides the functions of searching, replacing and segmenting byte slices. 4) The bytes.Reader type is suitable for reading data from byte slices, especially in I/O operations. 5) The bytes package works in collaboration with Go's garbage collector, improving the efficiency of big data processing.

You can use the "strings" package in Go to manipulate strings. 1) Use strings.TrimSpace to remove whitespace characters at both ends of the string. 2) Use strings.Split to split the string into slices according to the specified delimiter. 3) Merge string slices into one string through strings.Join. 4) Use strings.Contains to check whether the string contains a specific substring. 5) Use strings.ReplaceAll to perform global replacement. Pay attention to performance and potential pitfalls when using it.

ThebytespackageinGoishighlyeffectiveforbyteslicemanipulation,offeringfunctionsforsearching,splitting,joining,andbuffering.1)Usebytes.Containstosearchforbytesequences.2)bytes.Splithelpsbreakdownbyteslicesusingdelimiters.3)bytes.Joinreconstructsbytesli

ThealternativestoGo'sbytespackageincludethestringspackage,bufiopackage,andcustomstructs.1)Thestringspackagecanbeusedforbytemanipulationbyconvertingbytestostringsandback.2)Thebufiopackageisidealforhandlinglargestreamsofbytedataefficiently.3)Customstru

The"bytes"packageinGoisessentialforefficientlymanipulatingbyteslices,crucialforbinarydata,networkprotocols,andfileI/O.ItoffersfunctionslikeIndexforsearching,Bufferforhandlinglargedatasets,Readerforsimulatingstreamreading,andJoinforefficient

Go'sstringspackageiscrucialforefficientstringmanipulation,offeringtoolslikestrings.Split(),strings.Join(),strings.ReplaceAll(),andstrings.Contains().1)strings.Split()dividesastringintosubstrings;2)strings.Join()combinesslicesintoastring;3)strings.Rep


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Dreamweaver Mac version
Visual web development tools

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

SublimeText3 English version
Recommended: Win version, supports code prompts!

WebStorm Mac version
Useful JavaScript development tools
