用户定义的模板字符串

Question

I'm looking for a way to give a user an option to define template literal. That template will be sent to backend and used with the data he provided.

Example scenario:

const dataSentToBackend = [
  {
    name: 'Adam',
    country: 'Spain'
  },{
    name: 'Eve',
    country: 'Germany'
  }
]

User wants to generate two files that are like that: {name} from {country} (or anything else that let's him use tags how he like). So files in this example would be named as Adam from Spain and Eve from Germany .

The trick is that template needs to be preserved as a template so it can be used when data is actually being processed at the backend. So it can be used in a loop that names files one by one by the dataSentToBackend array.

So far I only found String.raw function (thanks to this page), but I didn't found it much helpful for me (or I didn't understood it).

Answer 1

Here's one way of doing it. I used the regular expression [az]+ for the property name which you could expand if you need to allow more characters (uppercase, underscores, numbers etc.)

 const dataSentToBackend = [ { name: 'Adam', country: 'Spain' }, { name: 'Eve', country: 'Germany' } ] const templateSentToBackend = "{name} from {country}"; serverSideReplace = (template, datas) => datas.map(data => template.replace(/\\{([az]+)\\}/g, (_, key) => data[key])); console.log(serverSideReplace(templateSentToBackend, dataSentToBackend));

Answer 2

Assuming that your user is inputing is template string in an input field. You can simple save an escaped string in your database, and unescape the same before compiling it into template string.

And to actually use it back you can try something like this.

const templateString = "Hello ${this.name}!"; // replace it with unescaped template 
const templateVars = {
    name: "world"    
}

const fillTemplate = function(templateString, templateVars){
    return new Function("return `"+templateString +"`;").call(templateVars);
}

console.log(fillTemplate(templateString, templateVars));

But i would definitely say don't let user define templates and use it, unless you have a really solid sanitizing script.