## SipaHelper
SipaHelper
Tool helper class with common helper methods
* [SipaHelper](#SipaHelper)
* [.mergeOptions(source, addition)](#SipaHelper.mergeOptions) → Object
* [.isArrayContainingEmptyValue(value)](#SipaHelper.isArrayContainingEmptyValue) → boolean
* [.validateParams(params)](#SipaHelper.validateParams)
* [.throwParamError(param_name, param, expected_type)](#SipaHelper.throwParamError)
* [.cutLeadingCharacters(text, leading_characters)](#SipaHelper.cutLeadingCharacters) → string
* [.cutTrailingCharacters(text, trailing_characters)](#SipaHelper.cutTrailingCharacters) → string
* [.constantizeString(constant)](#SipaHelper.constantizeString) → \*
### SipaHelper.mergeOptions(source, addition) → Object
Merge default options (source) with custom options (addition)
Works only fine with one level depth, don't merge nested (Object) options, as references are copied then!
**Returns**: Object - merged object
| Param | Type |
| --- | --- |
| source | Object |
| addition | Object |
**Example**
```js
SipaHelper.mergeOptions({ a: 1, b: "two"},{b: "TWO", c: null });
// => { a: 1, b: "TWO", c: null }
```
### SipaHelper.isArrayContainingEmptyValue(value) → boolean
Check if given value is an array (slice) of size 1 and contains type empty
**Returns**: boolean - true if a array of size 1 and contains empty => [empty], if size is 1 and not of type empty then false
**Throws**:
- Error if array is not of size 1
| Param | Type |
| --- | --- |
| value | any |
**Example**
```js
let arr = ["one"];
delete arr[1]:
arr;
// => [empty]
SipaHelper.isArrayContainingEmptyValue(arr);
// => true
```
### SipaHelper.validateParams(params)
Check the given parameter to be of the expected type.
If it is not valid, throw an exception.
**Throws**:
- Error throws an error if given parameter is not valid.
| Param | Type |
| --- | --- |
| params | [Array.<SipaParamValidation>](#SipaParamValidation) |
**Example**
```js
function Example(param_one, other_param) {
SipaHelper.validateParams([
{param_name: 'param_one', param_value: param_one, expected_type: 'Object'},
{param_name: 'other_param', param_value: other_param, expected_type: 'boolean'},
]);
}
Example("one",true);
// => Invalid parameter 'param_one' given. Expected type 'Object' but got type 'string'!`
```
### SipaHelper.throwParamError(param_name, param, expected_type)
Throw an exception for invalid parameter
**Throws**:
- Error always throws an error
| Param | Type | Description |
| --- | --- | --- |
| param_name | string | |
| param | any | |
| expected_type | string | e.g. 'Object', 'string, 'Array', 'number', ... |
**Example**
```js
SipaHelper.throwParamError('param_one', "one", 'Object');
// => Invalid parameter 'param_one' given. Expected type 'Object' but got type 'string'!
```
### SipaHelper.cutLeadingCharacters(text, leading_characters) → string
Cut leading characters (string) from given text.
**Throws**:
- Error when text or leading_characters are not strings
| Param | Type | Description |
| --- | --- | --- |
| text | string | to cut |
| leading_characters | string | to cut from text |
**Example**
```js
.cutLeadingCharacters('/some/path/is/that','/')
// => 'some/path/is/that'
```
### SipaHelper.cutTrailingCharacters(text, trailing_characters) → string
Cut trailing characters (string) from given text.
**Throws**:
- Error when text or trailing_characters are not strings
| Param | Type | Description |
| --- | --- | --- |
| text | string | to cut |
| trailing_characters | string | to cut from text |
**Example**
```js
.cutLeadingCharacters('/some/path/file.ext','.ext')
// => 'some/path/file'
```
### SipaHelper.constantizeString(constant) → \*
Transform the given string into its constant representation.
If the representation does not exist, an exception is thrown.
**Throws**:
- Error when constant does not exist or name is invalid
| Param | Type |
| --- | --- |
| constant | string |
**Example**
```js
class Foo {
static function bar() { console.log("foobar"); }
}
SipaHelper.constantizeString("Foo").bar();
// => foobar
```
## SipaParamValidation : Object
Custom type definitions for excellent IDE auto complete support
**Properties**
| Name | Type | Description |
| --- | --- | --- |
| param_value | any | |
| param_name | string | |
| expected_type, | string | e.g. 'Object', 'String, 'Array', ... |