A static archive of Markus Tacker's tweets. Follow me on Mastodon: @[email protected].
The other day I replaced a dependency to printf, someone needed to put a string
in the middle of another string: printf('abc%sdef', val).
In ES6 this can be nicely substituted with: this function val =>abc${val}def.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals
What if the template is dynamic? >
Since Template Literals cannot be constructed at runtime, your template string
cannot come from a variable, but must be constructed using backticks (`). So if
you load the string from the database, it is as simple as replacing the
placholder.
Use very restrictive code like:
const templateString = 'abc${val}def' // could come from a database ... const
val = 'f00'; console.log(templateString.replace(/${val}/g, val))
which replaces the exact instace of the placeholder, nothing else.
Don't do things that evals all variables. In most cases (e.g. rendering an email
subject), the names of the variables are known and defined. Support only that.
In the original case of the code, there would have been ever only one
placeholder...