Replacing variable substring

Question

I have this string: <div id="attachment_16696" class="wp-caption alignnone" style="width: 460px">

And I want to have: <div id="attachment_16696" class="wp-caption alignnone" style="width: 275px">

I works almost. The only issue is, when its for example 1000px, because it doesnt match it doesnt work, How can I handle if it is not 460px and I want to have it 260px ?

why not do, replaceString 460 with 260?

Anoop Vaidya
– Anoop Vaidya

2013-03-30 18:34:51 +00:00
Commented Mar 30, 2013 at 18:34 — Anoop Vaidya
– Anoop Vaidya, Commented Mar 30, 2013 at 18:34
because content is variable, it is not anytime 460

user1163463
– user1163463

2013-03-31 11:37:22 +00:00
Commented Mar 31, 2013 at 11:37 — user1163463
– user1163463, Commented Mar 31, 2013 at 11:37

Elliott · Accepted Answer · 2013-03-31 14:03:48Z

3

The following code uses the NSRegularExpression class to replace the width style attribute of a divs HTML markup when supplied in the format you specified:

// Takes Div markup in the following formats:
// <div id="something" class="something" style="width: Xpx">
// <div id="something" class="something" width="X">
// And replaces X with desired value.
- (NSString *)setDivMarkup:(NSString *)markup width:(NSInteger)width
{
    NSString *regexToReplaceWidth = @"width(:|=)(\")?\\s*\\d+\\s*(px)?";

    NSError *error = NULL;
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:regexToReplaceWidth
                                                                           options:NSRegularExpressionCaseInsensitive
                                                                             error:&error];

    return [regex stringByReplacingMatchesInString:markup
                                           options:0
                                             range:NSMakeRange(0, markup.length)
                                      withTemplate:[NSString stringWithFormat:@"width$1$2%d$3", width]];
}

edited Mar 31, 2013 at 14:03

answered Mar 30, 2013 at 21:18

Elliott

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7 Comments

crimson_penguin Over a year ago

I would suggest using \s* like in mine, rather than a space. But otherwise looks good I think.

Elliott Over a year ago

@crimson_penguin Makes a good point. Since any number of whitespace between 'width:' and its associated number is still valid markup you may want to replace the regular expression with the following: NSString *regexToReplaceWidth = @"width:\\s*\\d+px";.

user1163463 Over a year ago

Works very good, but there is one more problem: Sometimes the width is styled like width="460". I tried this regex but it doesn´t work: NSString *regexToReplaceWidth = @"width=\"\\d\"";

Elliott Over a year ago

Well this makes things significantly more complicated. I assume when it is in that format it is its own standalone attribute as opposed to within the 'style' attribute e.g.: <div id="attachment_16696" class="wp-caption alignnone" width="460"> and as such will require the double quotes around the value to remain valid markup?

user1163463 Over a year ago

Yes, so I can't change that ?

|

crimson_penguin · Accepted Answer · 2013-03-30 18:34:45Z

1

Use a regex: string.replace(/width:\s*\d+px/, 'width: 275px')

EDIT: On second thought, if this is only part of a much bigger string, you probably don't want to replace all widths with 275px (or 260px). You should still use a regex, but I'm not sure exactly what it would be looking for without seeing the context that this is in, and knowing what you do and don't want to replace.

answered Mar 30, 2013 at 18:34

crimson_penguin

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2 Comments

crimson_penguin Over a year ago

Yeah, this didn't actually specify a language. I was thinking "wait, how is this iPhone related?", but for some reason I assumed it was javascript, because it was operating on HTML.

crimson_penguin Over a year ago

If you do happen to be using javascript, or someone else is reading this, the usage of the above code is: <code>string</code> is the string you want to run the replacement on, and it'll return the result.

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