12.4. Find and Replace Setting

This setting, as its name implies, is used to find certain things and replace them with certain things. All find-replace settings in the plugin has the following three input fields:

Regex

A checkbox. When checked, it indicates that the values entered into find and replace inputs should be treated as regular expressions.

Find

A text to be searched. If regex checkbox is checked, you can enter a regular expression.

When writing a regex, if you want to use delimiters, you can use /. If the expression does not start with /, it is considered as it does not have delimiters. In that case, forward slashes will be automatically added.

Note

This input is case-sensitive. It means that test will not match Test.

If you want to make this input case-insensitive, you can check regex checkbox and enter /test/i. i is a flag that indicates the regular expression should be case-insensitive. This will match Test, test, TeST or tEst. Of course, you should escape special characters in your search text since you made it a regular expression. For example, if you want to search for a.text, you should escape . character since it is a meta sequence character in regular expressions. To escape characters that have meaning in regular expressions but you want to treat them as just plain characters, just prepend \, such as /a\.text/i.

Note

When writing regular expressions into this input, make sure you escaped / character since the plugin treats it as a delimiter. To escape it, just prepend a \. In other words, instead of /, write \/.

/ character that is used as a delimiter must not be escaped.

Tip

You can test your regular expressions on Regex101 (make sure flavor is selected as PHP). The site color-codes the regular expression parts, explains the regex, shows capture groups, makes it possible to share your regular expressions, and has many other features.

Replace

A text that will be inserted instead of the text found by found input. When using regular expressions, you can use $<group-number> to refer to a match group. For example, $1 is the match group 1 and $2 is the match group 2.

Additionally, a button is available for each find-replace setting. When you click this button, the find-replace configuration is tested. The test text can sometimes be written by you or it can be retrieved from the target web site. An example find-replace test can be seen in Fig. 12.11.

Fig. 12.11 A sample find-replace configuration. The test results show the replacement.

Tip

Regular expressions is a very broad topic that has countless tutorials and examples on the Internet. You can just search for tutorials on Google to learn more about regular expressions.

12.4.1. Examples

This section contains a few examples of using find-replace options. The following examples are given in the following format:

Subject:This is the text in which something will be replaced with something. Regex:This shows whether the regex checkbox is checked or not. If checked, this will have Checked value. Otherwise, this will have Not checked value. Find:The text written into find input. Replace:The text written into replace input. Result:The Subject after find-replace settings are applied.

12.4.1.1. Find and replace a word in a sentence in a case-sensitive way

Subject:This is a sample text. Regex:Not checked Find:This Replace:That Result:That is a sample text.

12.4.1.2. Remove a word from a sentence

Subject:This is a sample text. Regex:Not checked Find:This Replace: Result:is a sample text.

12.4.1.3. Find and replace a word in a sentence in a case-insensitive way

Subject:This is a sample text. A sample text is this. Regex:Checked Find:/this/i Replace:That Result:That is a sample text. A sample text is That.

12.4.1.4. Find and replace by using a regular expression

Subject:The numbers from zero to nine are 0123456789. Regex:Checked Find:[0-9]+ Replace:REPLACED Result:The numbers from zero to nine are REPLACED.

12.4.1.5. Find and use something from the found text in the replacement

Subject:

The phone number of the company is 123 456 78 90.

Regex:

Checked

Find:

^[^0-9]+(.*)\.$

^:Start from the beginning of the text [^0-9]+:Select everything until there is a number (.*):Select everything and create a capture group, which is the capture group 1. \.:Select the character .. We escape it by using \ because . has a special meaning in regular expressions. We do not want that special meaning. We want to match the . character. $:Select the end of the text

This regex means that start from the beginning of the text, match everything until there is a number. Next, select everything until there is a . character that is at the end of the text and group them. Now, we can use $1 to substitute the phone number in the replace input. 1 means the first capture group. A capture group is the match between parenthesis, which is (.*). Since it is the first capture group, we will use $1.

Replace:

Phone number: $1

Result:

Phone number: 123 456 78 90

12.4.1.6. Replace data-src attribute’s value with src attribute’s value

Subject:

<img src="dummy-src.jpg" data-src="real-src.jpg">

Regex:

Checked

Find:

<img src="([^"]+)" data-src="([^"]+)">

<img src=":Literally match <img src=" ([^"]+):Match everything until " character and group them. " data-src=":Literally match " data-src=" ([^"]+):Match everything until " character and group them. ">:Literally match ">

Here, the first capture group, i.e. $1, contains dummy-src.jpg, while the second one, i.e. $2, contains real-src.jpg.

Replace:

<img src="$2" data-src="$1">

Result:

<img src="real-src.jpg" data-src="dummy-src.jpg">