# Description
Enhance NFunction sanitization and support advanced functions:
- Start page counting from 1 rather than 0 as PDFs are one based from
the user's perspective, thus functions results would be affected by
starting with "0" rather than "1".
- Ignore out of bound results rather than stopping iterations to work
with functions such as (n - 4) when page count is 10 as we would get
positive values when n > 4.
- Remove spaces to support expressions such as 2n + 1 rather just 2n+1.
- Support advanced functions as follows:
- Support expressions such as follows 5(n-1), n(n-1), expressions
followed by opening rounded without '*' operator.
- Support expressions such as follows (n-1)5, (n-1)n, expressions
preceded closing rounded without '*' operator.
- Support consecutive "n" expressions, examples: nnn, 2nn, nn*3, nnnn.
Closes #(issue_number)
## Checklist
- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have performed a self-review of my own code
- [ ] I have attached images of the change if it is UI based
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] If my code has heavily changed functionality I have updated
relevant docs on [Stirling-PDFs doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
- [x] My changes generate no new warnings
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)
# Description
This pull request includes several changes aimed at improving the code
structure and removing redundant code. The most significant changes
involve reordering methods, removing unnecessary annotations, and
refactoring constructors to use dependency injection.
Autowired now comes via constructor (which also doesn't need autowired
annotation as its done by default for configuration)
## Checklist
- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have performed a self-review of my own code
- [ ] I have attached images of the change if it is UI based
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] If my code has heavily changed functionality I have updated
relevant docs on [Stirling-PDFs doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
- [ ] My changes generate no new warnings
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)
- Remove draggable.js as the draggability feature already works without and it wasn't used anywhere except in sign.html (which throw an exception already as draggableElement was null, and yet the functionality was working as expected, thus we don't need it)
