Correctly evaluating string value and format it in JavaScript

Question

I need some assistance with correctly implementing a method that uses .split and .replace to format a string value passed to it.

The string value is 90% of the time an HTML link as per this example: <a href=\"http://www.fnb.co.za\" rel=\"nofollow\">SMC RBJacobs</a>. But sometimes it only contains a normal string value such as: SMC RBJacobs.

I thought it would be a good idea to evaluate the value by checking .indexOf('</a>'), but this evaluates to true all the time.(?) I then get an error in the next statements executed in my method.

Here is my method:

if (col.name === 'twitter_tweet.source') {
    var str = value;
    if (value != null || value != undefined) {
        if (value.indexOf('</a>')) {
            var parts = str.split('"nofollow\">');
            var value = parts[1].replace('</a>', '');
            return value;
        }
    }
    return value;
}

The desired output regardless of whether the string contains HTML markup or not: SMC RBJacobs (or whichever name is passed)

Any help would be appreciated!

better use regexp, its better for me in that type of issues. — Álvaro Touzón
– Álvaro Touzón, Commented Feb 16, 2017 at 7:05
.indexOf() returns -1 if the search value has not been found, hence the if condition is wrong and should be if (value.indexOf('</a>') > -1) { ... } — Andreas
– Andreas, Commented Feb 16, 2017 at 7:09
@ÁlvaroTouzón that is a good idea. Do you perhaps have something in mind that will work in this situation? — onmyway
– onmyway, Commented Feb 16, 2017 at 7:15

elclanrs · Accepted Answer · 2017-02-16 07:08:52Z

3

indexOf always returns a number, not a boolean. If found, the index will be zero or more. If not found the index will be -1. So you want to check like:

if (value.indexOf('</a>') > -1) {

If you can have different tags and spacing I would suggest using something less brittle like jQuery:

if ($(value).length) {
  return $(value).text();
}

answered Feb 16, 2017 at 7:08

elclanrs

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1 Comment

onmyway Over a year ago

I can't believe it slipped my mind (returning a value and not a boolean)! Thank you for your help!

Cezary Tomczyk · Accepted Answer · 2017-02-16 07:15:57Z

0

I'd try following approach:

var str = '<a href=\"http://www.fnb.co.za\" rel=\"nofollow\">SMC RBJacobs</a>',
el = document.createElement('div'),
result;

el.innerHTML = str;
result = el.textContent;

console.log(result);

Note #1: I assume here that HTML string is safe. Note #2: str can be an HTML or string.

Working example: https://jsfiddle.net/655uqc0f/

answered Feb 16, 2017 at 7:15

Cezary Tomczyk

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1 Comment

onmyway Over a year ago

Thanks for the help. I am retrieving the value from a DB through, and not from my view. :)

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