CODEWITHSUNDEEP
gotemplatesgo-templatesgoland
Shivakumar ss
Shivakumar ss

Reputation: 663

Disable method evaluation inside template

I am using Go for template evaluation and the following is my use case.

We have our application in which we ask customers to include prefixed-based placeholders along with their text.

E.g.:

my name is {$.PRE.FIRSTNAME}

This will be automatically replaced with their first name, this is just a simple text, there will be more complex text which will be entered by the customer. it can even be a HTML.

following is the code snippet

Over here the first templateText works perfectly file and the second commented one doesn't work. it throws an exception stating a function not defined.

package main

import (
    "bytes"
    "html/template"
    "log"
)

// OuterObject  object
type OuterObject struct {
    PRE *InnerObject
}

// InnerObject macro object
type InnerObject struct {
    FIRSTNAME, LASTNAME string
}

func main() {
    // This works perfectly.
    templateText := "my name is {$.PRE.FIRSTNAME}  "
    // templateText := "my name is {$.PRE.FIRSTNAME} ().push(function() { globalAml.display('sss') };"
    //
    // Above templateText fails with exception :
    // function "globalAml" not defined
    //
    o := &OuterObject{
        PRE: &InnerObject{
            FIRSTNAME: "fName",
            LASTNAME:  "lName",
        },
    }

    var doc bytes.Buffer
    t, err := template.New("test").Delims("{", "}").Parse(templateText)

    if err != nil {
        log.Fatal("Error parsing tag", err)
    }
    err1 := t.Execute(&doc, o)
    if err1 != nil {
        log.Println("Error Execute tag", err1)
    }
    log.Println("Final text ", doc.String())
}

Can anyone help me to ignore the method calls and just to replace the prefixed-based placeholders.

Upvotes: 1

Views: 370

Answers (2)

Shivakumar ss
Shivakumar ss

Reputation: 663

I was temporarily able to handle this case by changing the code snippet to following :

t, err := template.New("test").Delims("{$", "}").Parse(templateText)

I know this will fail in cases where customer entering a text containing these above delimiters.

Thanks a lot, guys.

Upvotes: 2

Konrad Rudolph
Konrad Rudolph

Reputation: 545875

Your second substitution fails because { and } are the template delimiters. You need to quote them to make this work:

templateText := "my name is {$.PRE.FIRSTNAME} ().push(function() {`{`} globalAml.display('sss') {`}`};"

Upvotes: 0

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