将JSON文件读取到自定义类型结构中，我需要在需要类型字符串而不是自定义类型的函数中使用键

Question

I'm creating a tool that can take a JSON file, and then create a PDF out of it using Go

Here is an example of my JSON:

[{"Name":"Ollie","Age":"25","Comment":"This is my comment"},{"Name":"Amy","Age":"28","Comment":"Another comment"},{"Name":"Joey","Age":"19","Comment":"Comment from Joey"},{"Name":"James","Age":"23","Comment":"James' comment"},{"Name":"Richard","Age":"20","Comment":"Richard has also made 24"}]

I have something that works from using CSV files, but now I want to be able to take JSON files too

The package that i'm using to create the PDFs is gofpdf

One of the issues is that I need to pass the JSON into a struct to read it, the struct has it's own custom type - because i'm using a custom type I can't pass in the values into gofpdf's functions to make the PDF

I simply want to be able to pass the values from my struct (which are declared as strings) as strings in the functions:

package main

import (
    "encoding/json"
    "fmt"
    "io/ioutil"
    "log"
    "time"

    "github.com/jung-kurt/gofpdf"
)

Here is my struct:

type Person struct {
    Name    string `json:"Name"`
    Age     string `json:"Age"`
    Comment string `json:"Comment"`
}

func main() {

    data, err := ioutil.ReadFile("csv-to-json.json")
    if err != nil {
        fmt.Println(err)
    }

    //create variable people which is array of Person structs
    var People []Person

    //Take the data object (json file) and place into the People array of struct
    json.Unmarshal(data, &People)

    fmt.Println(People[:])

    pdf := NewReport()

    pdf = CreateTableJSON(pdf, People[:])

    if pdf.Err() {
        log.Fatalf("Failed creating PDF report: %s
", pdf.Error())
    }

    err = SavePDFJSON(pdf)
    if err != nil {
        log.Fatalf("Cannot save PDF: %s|n", err)
    }
}

func CreateTableJSON(pdf *gofpdf.Fpdf, table []Person) *gofpdf.Fpdf {
    for _, str := range table {

BELOW IS WHERE I AM STRUGGLING. str needs to be of type string

        pdf.CellFormat(20, 7, str, "1", 0, "C", false, 0, "")

        pdf.Ln(-1)
    }
    return pdf
}

//Create function that generates a new pdf report
func NewReport() *gofpdf.Fpdf {
    pdf := gofpdf.New("P", "mm", "Letter", "")
    pdf.AddPage()
    pdf.SetFont("Arial", "B", 28)
    pdf.Cell(40, 10, "My title for the PDF (New)!")
    pdf.Ln(12)
    pdf.SetFont("Arial", "", 11)
    pdf.Cell(40, 10, time.Now().Format("Mon Jan 2, 2006"))
    pdf.Ln(12)

    return pdf
}


func SavePDFJSON(pdf *gofpdf.Fpdf) error {
    return pdf.OutputFileAndClose("pdf_from_json.pdf")
}

So i'm able to read the data from the JSON file and print the lines to the console, but I can't use this data in the PDF generation functions since i've had to create a custom types, and the function parameters are expecting strings. Can anyone help me out here? I want the equivalent of this:

pdf.CellFormat(20, 7, **TOSTRING(str)**, "1", 0, "C", false, 0, "")

I've been messing around for about 3 hours now without any luck

Thanks in advance

Answer 1

You need to implement (p *Person) String() string so that you can get a string representation of a Person.

For example:

func (p *Person) String() string {
  return fmt.Sprintf("%s age %d says %q", p.Name, p.Age, p.Comment)
}

// ...
pdf.CellFormat(20, 7, str.String(), "1", 0, "C", false, 0, "")