4 Simple Steps To Remove Map Keywork When Printing Golang

Many developers prefer to use Map[string]interface{}. However, when we want to print out the result of the map, we will get a bunch of unreadable content. Therefore, we need to remove the map keywork when printing the map.

There are several ways to do this. One way is to use the fmt.Println() function. The fmt.Println() function will print the value of the map, but it will not print the map key. Another way to remove the map keywork is to use the reflect.Value.String() method. The reflect.Value.String() method will return a string representation of the value of the map, but it will not include the map key.

Finally, we can also use the encoding/json package to remove the map keywork. The encoding/json package can be used to encode and decode JSON data. When we encode a map using the encoding/json package, the map keywork will be removed from the resulting JSON data.

Identify the Keywork to Remove

When printing a map using the `fmt` package in Go, the default format includes the type assertion map[K]V. To remove this type assertion, you need to specify a custom format string.

The format string is a sequence of verbs that determine how the value is formatted. For maps, the `%v` verb is used to print the map’s contents. To remove the type assertion, you can use the `%#v` verb instead. The `#` flag suppresses the type assertion and prints the map’s contents without the `map[]` prefix.

Here’s an example of how to use the `%#v` verb to remove the type assertion when printing a map:

“`go
package main

import “fmt”

func main() {
m := map[string]int{“Alice”: 20, “Bob”: 25}
fmt.Printf(“%#v\n”, m)
}
“`

Output:

“`
map[Alice:20 Bob:25]
“`

As shown in the output, the type assertion `map[]` is removed when using the `%#v` verb.

Use the Go Print Package

The Go print package provides several functions to format and print data. It can handle various data types, including maps. To suppress the map keywork when printing a map, you can use the following steps:

2. Use the Fprintf Function

The Fprintf function takes a writer (such as os.Stdout) and a format string as its first two arguments. The format string specifies how the data should be formatted. To suppress the map keyword, you can use the following format string:

“`go
fmt.Fprintf(os.Stdout, “%#v\n”, m)
“`

The %#v specifier prints the map in a human-readable format, but without the map keyword. The resulting output will look like this:

“`
map[key1:value1 key2:value2]
“`

Additional Notes

Here are some additional notes to consider when using the Fprintf function:

Parameter	Description
writer	The destination to which the formatted data will be written. It can be any type that implements the io.Writer interface, such as os.Stdout or a file.
format string	A string that specifies how the data should be formatted. It can contain format specifiers to control the output.
data	The data to be formatted. It can be any type, including maps, slices, structs, and primitive values.

Utilize the PageRanges Option

The `PageRanges` option in Go’s `html/pdf` package offers a precise solution to exclude specific pages from the printed output. This option accepts a slice of page ranges, where each range is defined as a pair of integers representing the start and end pages. Pages outside the specified ranges are excluded from the PDF, while pages within the ranges are included.

For example, to exclude only the first page from a 5-page document, use the following code:

“`go
pageRanges := [][2]int{{2, 5}}
pdf.Configure(pdf.PageRanges(pageRanges))
“`

This approach provides granular control over which pages to include or exclude, allowing users to create custom printing configurations tailored to their specific requirements. The flexibility of the `PageRanges` option makes it a versatile solution for generating PDF printouts with customized page selection.

Customize Page Margins

To adjust the margins around the printed output, you can specify the Margins field in the PageSetup struct. The Margins field takes a set of dimensions, each representing a side of the page. The margins are specified in inches, with the following default values:

Side	Default Margin (inches)
Top	1
Right	1
Bottom	1
Left	1

You can adjust these margins to fit your specific printing needs. For example, if you want to increase the top margin to 1.5 inches, you would set the Top field in the Margins struct to 1.5.

Here is an example of setting custom page margins:

func examplePrintCustomMargins(w io.Writer) error {
	doc := goxl.NewDocument("My Document")
	page := doc.AddPage()
	page.SetPageSetup(&goxl.PageSetup{
		Margins: &goxl.Margins{
			Top:    1.5,
			Right:  0.5,
			Bottom: 1,
			Left:   0.5,
		},
	})
	// Continue adding content to the page...
	if _, err := doc.Write(w); err != nil {
		return err
	}
	return nil
}

Manipulate Header and Footer Content

You can set up different header and footer configurations for each page of your document. Header and footer content is managed independently of the existing layout.

Predefined Headers and Footers

There are some predefined headers and footers available as constants:

List of Predefined Headers and Footers

	Description
`html2pdf.HDefault`	Default header
`html2pdf.HNo`	No header
`html2pdf.HTopLeft`	Header containing only the page number (top left)
`html2pdf.HTopCenter`	Header containing only the page number (top center)
`html2pdf.HTopRight`	Header containing only the page number (top right)
`html2pdf.FDefault`	Default footer
`html2pdf.FNo`	No footer

You can assign one of the predefined headers or footers to a page:

import (
    "bytes"
    "fmt"

    "github.com/SebastiaanKlippert/go-wkhtmltopdf"
)

func main() {
    pdfg, err := wkhtmltopdf.NewPDFGenerator()
    if err != nil {
        fmt.Println("Error:", err)
        return
    }

    page := wkhtmltopdf.NewPage("https://github.com/SebastiaanKlippert/go-wkhtmltopdf")
    page.FooterRight.Contents = wkhtmltopdf.FDefault

    pdfg.AddPage(page)

    pdfg.PageSize.Set("A4")

    pdfBytes, err := pdfg.CreatePDF()
    if err != nil {
        fmt.Println("Error:", err)
        return
    }

    _ = bytes.NewReader(pdfBytes)
}

You can also define custom header or footer content using HTML:

    headerContent := `My Custom Header`

    page.HeaderLeft.Contents = headerContent

Leverage the CSS Style Attribute

The CSS style attribute provides an effective method to conceal map keywork when printing. To achieve this, apply the ‘display’ property to the ‘none’ value for the element containing the map keywork. This action renders the element invisible during the printing process while maintaining its visibility on the screen. Implementing this solution involves the following steps:

1. Identify the Element

Locate the HTML element that encloses the map keywork. This element typically possesses a class or ID attribute that distinguishes it from other page elements.

2. Define the CSS Rule

In the CSS stylesheet, create a rule that targets the identified element. Use the ‘display’ property to set the value to ‘none’ for the ‘print’ media type.

3. Example

Consider the following CSS rule:

CSS
`.map-keywork { display: none; print; }`

This rule specifies that any HTML element with the class ‘map-keywork’ will be hidden when the document is printed.

4. Apply the CSS Rule

Ensure that the CSS rule is applied to the web page. This can be achieved by linking an external stylesheet or embedding the CSS rules directly into the HTML document.

5. Test the Solution

Preview the web page and verify that the map keywork is visible on the screen. Subsequently, print the document to confirm that the keywork is hidden.

Use External HTML and CSS Files

You can also use external HTML and CSS files to define the styling of your printed document. This can be useful if you want to use a shared template or style across multiple print jobs.

9. Using CSS to Hide Elements

You can use CSS to hide elements that you don’t want to appear on the printed page. For example, you might want to hide the map legend or other elements that are only useful when viewing the map online. To do this, you can add the following CSS to your stylesheet:

CSS	Description
`.element-to-hide { display: none; }`	Hides the element with the class `element-to-hide`

You can also use the visibility property to hide elements. However, this will still render the element on the page, so it may not be the best option if you want to save ink and paper.

To hide elements using the visibility property, you can add the following CSS to your stylesheet:

CSS	Description
`.element-to-hide { visibility: hidden; }`	Hides the element with the class `element-to-hide`

Apply Page Orientation Settings

To change the orientation of your print job, follow these steps:

From the Home tab, click the Page Setup button.
In the Page Setup dialog box, click the Paper Size tab.
In the Orientation section, select the desired orientation.
Click OK to save your changes.

Portrait Orientation

Portrait orientation is the default orientation for most printers. It is taller than it is wide, and is ideal for printing documents that are primarily text-based.

Landscape Orientation

Landscape orientation is wider than it is tall, and is ideal for printing documents that are primarily image-based or that require a wider layout.

Orientation	Recommended for
Portrait	Text-based documents, letters, résumés
Landscape	Image-based documents, spreadsheets, presentations

How To Remove Map Kepwork When Printing Golang

Map keys are printed in Go by default, and there is no built-in way to remove them. However, there are a few ways to work around this.

One way is to use a custom print function. The following code defines a print function that only prints the values of a map:

“`go
func PrintValues(m map[string]interface{}) {
for _, v := range m {
fmt.Println(v)
}
}
“`

This function can be used to print a map without its keys:

“`go
m := map[string]interface{}{
“name”: “John Doe”,
“age”: 30,
}

PrintValues(m)
“`