Last active
April 25, 2023 22:16
-
-
Save zenparsing/5dffde82d9acef19e43c to your computer and use it in GitHub Desktop.
Dedenting Template Strings
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| function dedent(callSite, ...args) { | |
| function format(str) { | |
| let size = -1; | |
| return str.replace(/\n(\s+)/g, (m, m1) => { | |
| if (size < 0) | |
| size = m1.replace(/\t/g, " ").length; | |
| return "\n" + m1.slice(Math.min(m1.length, size)); | |
| }); | |
| } | |
| if (typeof callSite === "string") | |
| return format(callSite); | |
| if (typeof callSite === "function") | |
| return (...args) => format(callSite(...args)); | |
| let output = callSite | |
| .slice(0, args.length + 1) | |
| .map((text, i) => (i === 0 ? "" : args[i - 1]) + text) | |
| .join(""); | |
| return format(output); | |
| } | |
| let output; | |
| console.log("=== As a string function ==="); | |
| output = dedent(` | |
| this | |
| is | |
| the ${ "end" } | |
| my only | |
| friend | |
| the end | |
| `); | |
| console.log(output); | |
| console.log("=== As a template tag ==="); | |
| output = dedent` | |
| this | |
| is | |
| the ${ "end" } | |
| my only | |
| friend | |
| the end | |
| `; | |
| console.log(output); | |
| console.log("=== As a higher-order template tag ==="); | |
| output = dedent(String.raw)` | |
| this | |
| is | |
| the ${ "end" } | |
| my only | |
| friend | |
| the \end | |
| `; | |
| console.log(output); |
+1 for Jim Morrison
This is a fantastic utility! Any recommendation on how to get a hard return (\n and maybe \r\n) between two sets of de-dented content?
I'm creating a string for an *.eml file, and it's VERY finicky. I must supply a \n before the html section (see screenshot).
Although my output technically works, it would be cool to eliminate the 4 spaces ahead of <html>. But, I admit, it's probably a bit pedantic.
What I tried: I attempted to separate the header and body, and then recombine them with a \n via a template literal string, but it didn't work... actually it would not respect that \n at all.
structuredEmail = `${header}\n${body}
//new line not in output ----->>>> now that I think of it, it should probably be two: \n\n
==== UPDATE: A FEW MOMENTS LATER ====
Okay, I fixed it this way:
const structuredEmail = dedent(`To:
Subject: ${subject}
X-Unsent: 1
Content-Type: text/html
\n<html>
<body>
<h2>Job Description</h2>
${JobDescription}
<h2>Qualifications</h2>
${Qualifications}
</body>
</html>
`);
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
@mathiasbynens Thanks !