Merge pull request #1957 from codeigniter4/stringrule

New generic string validation rule.

Author: lonnieezell

system/Validation/FormatRules.php

@@ -121,6 +121,23 @@ public function alpha_numeric_space(string $str = null): bool
 
 	//--------------------------------------------------------------------
 
+	/**
+	 * Any type of string
+	 *
+	 * Note: we specifically do NOT type hint $str here so that
+	 * it doesn't convert numbers into strings.
+	 *
+	 * @param string|null $str
+	 *
+	 * @return boolean
+	 */
+	public function string($str = null): bool
+	{
+		return is_string($str);
+	}
+
+	//--------------------------------------------------------------------
+
 	/**
 	 * Decimal number
 	 *

tests/system/Validation/FormatRulesTest.php

@@ -325,6 +325,47 @@ public function ipProvider()
 
 	//--------------------------------------------------------------------
 
+	/**
+	 * @dataProvider stringProvider
+	 *
+	 * @param $str
+	 * @param $expected
+	 */
+	public function testString($str, $expected)
+	{
+		$data = [
+			'foo' => $str,
+		];
+
+		$this->validation->setRules([
+			'foo' => 'string',
+		]);
+
+		$this->assertEquals($expected, $this->validation->run($data));
+	}
+
+	//--------------------------------------------------------------------
+
+	public function stringProvider()
+	{
+		return [
+			[
+				'123',
+				true,
+			],
+			[
+				123,
+				false,
+			],
+			[
+				'hello',
+				true,
+			],
+		];
+	}
+
+	//--------------------------------------------------------------------
+
 	/**
 	 * @dataProvider alphaProvider
 	 *

user_guide_src/source/libraries/validation.rst

@@ -660,31 +660,30 @@ alpha_dash              No          Fails if field contains anything other than
 alpha_numeric           No          Fails if field contains anything other than alpha-numeric characters or numbers.
 alpha_numeric_space     No          Fails if field contains anything other than alpha-numeric characters, numbers or space.
 decimal                 No          Fails if field contains anything other than a decimal number.
-differs                 Yes         Fails if field does not differ from the one in the parameter.                                    differs[field_name]
-equals                  Yes         Fails if field is not exactly the parameter value.
-exact_length            Yes         Fails if field is not exactly the parameter value in length. One or more comma-separated values. exact_length[5] or exact_length[5,8,12]
-greater_than            Yes         Fails if field is less than or equal to the parameter value or not numeric.                      greater_than[8]
-greater_than_equal_to   Yes         Fails if field is less than the parameter value, or not numeric.                                 greater_than_equal_to[5]
-in_list                 Yes         Fails if field is not within a predetermined list.                                               in_list[red,blue,green]
+differs                 Yes         Fails if field does not differ from the one in the parameter.                                   differs[field_name]
+exact_length            Yes         Fails if field is not exactly the parameter value. One or more comma-separated values.          exact_length[5] or exact_length[5,8,12]
+greater_than            Yes         Fails if field is less than or equal to the parameter value or not numeric.                     greater_than[8]
+greater_than_equal_to   Yes         Fails if field is less than the parameter value, or not numeric.                                greater_than_equal_to[5]
+if_exist                No          If this rule is present, validation will only return possible errors if the field key exists,
+                                    regardless of its value.
+in_list                 Yes         Fails if field is not within a predetermined list.                                              in_list[red,blue,green]
 integer                 No          Fails if field contains anything other than an integer.
 is_natural              No          Fails if field contains anything other than a natural number: 0, 1, 2, 3, etc.
 is_natural_no_zero      No          Fails if field contains anything other than a natural number, except zero: 1, 2, 3, etc.
-less_than               Yes         Fails if field is greater than or equal to the parameter value or not numeric.                   less_than[8]
-less_then_equal_to      Yes         Fails if field is greater than the parameter value or not numeric.                               less_than_equal_to[8]
-matches                 Yes         The value must match the value of the field in the parameter.                                    matches[field]
-max_length              Yes         Fails if field is longer than the parameter value.                                               max_length[8]
-min_length              Yes         Fails if field is shorter than the parameter value.                                              min_length[3]
-not_equals              Yes         Fails if field is exactly the parameter value.
+is_unique               Yes         Checks if this field value exists in the database. Optionally set a                             is_unique[table.field,ignore_field,ignore_value]
+                                    column and value to ignore, useful when updating records to ignore itself.
+less_than               Yes         Fails if field is greater than or equal to the parameter value or not numeric.                  less_than[8]
+less_then_equal_to      Yes         Fails if field is greater than the parameter value or not numeric.                              less_than_equal_to[8]
+matches                 Yes         The value must match the value of the field in the parameter.                                   matches[field]
+max_length              Yes         Fails if field is longer than the parameter value.                                              max_length[8]
+min_length              Yes         Fails if field is shorter than the parameter value.                                             min_length[3]
 numeric                 No          Fails if field contains anything other than numeric characters.
-regex_match             Yes         Fails if field does not match the regular expression.                                            regex_match[/regex/]
-if_exist                No          If this rule is present, validation will only return possible errors if the field key exists,
-                                    regardless of its value.
+regex_match             Yes         Fails if field does not match the regular expression.                                           regex_match[/regex/]
 permit_empty            No          Allows the field to receive an empty array, empty string, null or false.
 required                No          Fails if the field is an empty array, empty string, null or false.
-required_with           Yes         The field is required when any of the other required fields are present in the data.             required_with[field1,field2]
-required_without        Yes         The field is required when all of the other fields are present in the data but not required.     required_without[field1,field2]
-is_unique               Yes         Checks if this field value exists in the database. Optionally set a                              is_unique[table.field,ignore_field,ignore_value]
-                                    column and value to ignore, useful when updating records to ignore itself.
+required_with           Yes         The field is required when any of the other required fields are present in the data.            required_with[field1,field2]
+required_without        Yes         The field is required when all of the other fields are present in the data but not required.    required_without[field1,field2]
+string                  No          A generic alternative to the alpha* rules that confirms the element is a string
 timezone                No          Fails if field does match a timezone per ``timezone_identifiers_list``
 valid_base64            No          Fails if field contains anything other than valid Base64 characters.
 valid_json              No          Fails if field does not contain a valid JSON string.