#5.1 Why can't I use Blockchain for data?

[achievermina]

main.go

package main

import (
	"html/template"
	"log"
	"net/http"

	Blockchain "github.com/achievermina/gocoin/blockchain"
)

const port string = ":8000"

type data struct {
	Blocks *Blockchain // I tried to use Blockchain instead of block[]. I have an error here. Can you let me know why? @serranoarevalo 
}

func home(rw http.ResponseWriter, r *http.Request) {
	tmpl := template.Must(template.ParseFiles("templates/home.gohtml"))
	data := data{Blockchain.GetBlockchain()}
	tmpl.Execute(rw, data)
}

func main() {
	chain := Blockchain.GetBlockchain()
	chain.AddBlock("Second")
	chain.AddBlock("Third Block")

	http.HandleFunc("/", home)
	log.Fatal(http.ListenAndServe(port, nil))
}

blockchain.go

package blockchain

import (
	"crypto/sha256"
	"fmt"
	"sync"
)

type Block struct {
	Data string
	Hash string
	PrevHash string
}

type Blockchain struct {
	Blocks []*Block
}

var b *Blockchain
var once sync.Once

func createBlock(data string) *Block {
	newBlock := Block{data, "", b.getLastHash()}
	newBlock.createHash()
	return &newBlock
}

func GetBlockchain() *Blockchain {
	if b == nil {
		once.Do(func () {
			b = &Blockchain{}
			b.Blocks = append(b.Blocks, createBlock("First Block"))
		})
	}
	return b;
}

func (b* Block) createHash() {
	hash := sha256.Sum256([]byte(b.Data + b.PrevHash))
	b.Hash = fmt.Sprintf("%x", hash)
}

func (b* Blockchain) getLastHash() string {
	if (len(b.Blocks) > 0 ) {
		return b.Blocks[len(b.Blocks)-1].Hash 
	}
	return ""
}

func (b* Blockchain) AddBlock(data string) {
	b.Blocks = append(b.Blocks, createBlock(data))
}

func(b* Blockchain) PrintBlocks() {
	for _, Block := range b.Blocks {
		fmt.Printf("Data: %s \n", Block.Data)
		fmt.Printf("Hash: %s \n", Block.Hash)
		fmt.Printf("PrevHash: %s \n", Block.PrevHash)
	}
}

[achievermina]

It works when I use. Can someone explain this please?

type data struct {
Blocks *Blockchain.Blockchain
}