Check if body tag is empty in text representing HTML

Question

This URL seems to bring to an empty HTML but looking at its source (CTRL+U) there's some style in it.

However, the body tag is empty and I would need a way to test it given that the only thing I have is the source representation as text (see below).

I've been reading an answer which might be of help but so far I could not find a proper way to apply it.

Any hint would be very much appreciated.

"<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\"><html xmlns:esri_wms=\"http://www.esri.com/wms\" xmlns=\"http://www.esri.com/wms\">\r\n<head>\r\n<meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\"></meta>\r\n<style type=\"text/css\">\r\n\t\t\t\t\ttable, th, td {\r\n\t\t\t\t\t\tborder:1px solid #e5e5e5;\r\n\t\t\t\t\t\tborder-collapse:collapse;\r\n\t\t\t\t\t\tfont-family: arial;\t\t\t\t\t\r\n\t\t\t\t\t\tfont-size: 80%;\t\t\t\t\t\t\r\n\t\t\t\t\t\tcolor: #333333\r\n\t\t\t\t\t} \t\t\t\t\t\r\n\t\t\t\t\tth, td {\r\n\t\t\t\t\t\tvalign: top;\r\n\t\t\t\t\t\ttext-align: center;\r\n\t\t\t\t\t}\t\t\t\t\t\r\n\t\t\t\t\tth {\r\n\t\t\t\t\t\tbackground-color: #aed7ff\r\n\t\t\t\t\t}\r\n\t\t\t\t</style>\r\n</head>\r\n<body></body>\r\n</html>\r\n"

Are you trying to run a check to see if there is HTML source code in the body? — www139, Sep 10 '18 at 22:20
@www139 something like that. Consider I don't have a DOM element but only a text var representing a "HTML web page" (as in the example). — umbe1987, Sep 10 '18 at 22:22
Instead of trying to work from your linked answer, look further down that question for usrbowe's answer and work from that. — Alohci, Sep 11 '18 at 00:10
@Alohci I think it is exactly what I need. Will try that asap. Thanks. — umbe1987, Sep 11 '18 at 05:59

Jack Bashford · Answer 1 · 2018-09-10T22:44:53.800

1

What you can do is use the innerHTML property of all HTML tags:

var text = "<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\"><html xmlns:esri_wms=\"http://www.esri.com/wms\" xmlns=\"http://www.esri.com/wms\">\r\n<head>\r\n<meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\"></meta>\r\n<style type=\"text/css\">\r\n\t\t\t\t\ttable, th, td {\r\n\t\t\t\t\t\tborder:1px solid #e5e5e5;\r\n\t\t\t\t\t\tborder-collapse:collapse;\r\n\t\t\t\t\t\tfont-family: arial;\t\t\t\t\t\r\n\t\t\t\t\t\tfont-size: 80%;\t\t\t\t\t\t\r\n\t\t\t\t\t\tcolor: #333333\r\n\t\t\t\t\t} \t\t\t\t\t\r\n\t\t\t\t\tth, td {\r\n\t\t\t\t\t\tvalign: top;\r\n\t\t\t\t\t\ttext-align: center;\r\n\t\t\t\t\t}\t\t\t\t\t\r\n\t\t\t\t\tth {\r\n\t\t\t\t\t\tbackground-color: #aed7ff\r\n\t\t\t\t\t}\r\n\t\t\t\t</style>\r\n</head>\r\n<body></body>\r\n</html>\r\n";
text.slice(1, -1);
var body = document.body;
body.replace(/ /g, "")

if (body == "") {
    console.log("Empty page"!);
}

edited Sep 10 '18 at 22:44

answered Sep 10 '18 at 22:21

Jack Bashford

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Exactly what I was going to write but I couldn't quite understand the question (+1). – www139 Sep 10 '18 at 22:21
1

No worries, I gave you +1 – Jack Bashford Sep 10 '18 at 22:22
Might want to trim that in case of whitespace inside tag – charlietfl Sep 10 '18 at 22:23
OK, now strips whitespace - thanks @RocketHazmat for your comment on [this answer](https://stackoverflow.com/questions/10800355/remove-whitespaces-inside-a-string-in-javascript) – Jack Bashford Sep 10 '18 at 22:23
@JBDouble05 But how can I getElementsByTagName if I don't have a "document" but a text representing a document as I showed in my example? – umbe1987 Sep 10 '18 at 22:25
The page source you gave us isn't a string, it's HTML. – Jack Bashford Sep 10 '18 at 22:26
There will only ever be one `body` tag so why use `getElementsByTagName()` only to extract the one element that is in the node list? Not to mention that `.getElementsByTagName()` has performance issues. Use `.querySelector("body")` or just `document.body` instead. – Scott Marcus Sep 10 '18 at 22:27
@JBDouble05 "given that the only thing I have is the source representation as text (see below)" this is my issue – umbe1987 Sep 10 '18 at 22:28
1

@umbe1987 Just strip off the double quotes and you'll have a HTML page. – Jack Bashford Sep 10 '18 at 22:32
It works. If you could add this in your answer, I'll be happy to accept it. Thanks! – umbe1987 Sep 10 '18 at 22:42
No problem. How did you strip the quotes? – Jack Bashford Sep 10 '18 at 22:43
text.slice(1, -1); – umbe1987 Sep 10 '18 at 22:43
Added. That better? – Jack Bashford Sep 10 '18 at 22:45
@JBDouble05 I',m really sorry. It does only remove the first and last char but it still remain a string. First and last char being "<" and "\n". Sorry again.... – umbe1987 Sep 10 '18 at 22:50
How do you think I'd fix that? – Jack Bashford Sep 10 '18 at 22:51
The expected behaviour of my app was to not show a message if body is empty. That was what happened using slice but I didn't notice a console error. – umbe1987 Sep 10 '18 at 22:55

Check if body tag is empty in text representing HTML

1 Answers1