# README
Utils Module
Module of simple, well-tested, and reusable Go utilities. Inspired by Trevor Sawler's "Building a Module in Go." Udemy course.
Most of the utilities in this module are based on Trevor Sawler's Toolbox module.
The utilities in this module:
RandomString()
RandomString generates and returns a string of a specified length of random characters. The characters are randomnly asembled from othe ptional characterSeed parameter, or they are sourced from the default set made up of the following characters:
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_+!@#$%*
func (u *Utils) RandomString(length int, characterSeed ...[]rune) string
UploadOneFile()
UploadOneFile is a convenience method that calls UploadFiles, but expects only one file to be in the upload.
func (u *Utils) UploadOneFile(r *http.Request, uploadDir string, rename ...bool) (*UploadedFile, error)
UploadFiles()
UploadFiles uploads one or more files from a multipart form submission contained within an http.Request to the specified uploadDir directory. It gives the files a random name. It returns a slice of UploadedFile structs, and potentially an error. If the optional last parameter is set to true, the files won't be renamed.
func (u *Utils) UploadFiles(req *http.Request, uploadDir string, rename ...bool) ([]*UploadedFile, error)
MakeDirStructure()
MakeDirStructure is a convenience method of the utils package which uses os.MkdirAll to creates a directory structure based on the slice of path strings provided. It returns nil when all the directories are successfully created, or else returns an error. The permission bits default to 0755, and are used for all directories created. If a path is already a directory, os.MkdirAll does nothing and returns nil, so MakeDirStructure will also return nil. If there's a permission issue encountered for any of the paths, the error reported by os.MkdirAll will be collected, and MakeDirStructure will return all encountered those errors as one.
func (u *Utils) MakeDirStructure(pathsToBeMade []string) error
CrawlLogPaths()
CrawlLogPaths: given a starting path, it will crawl the directory hierachy below that path, and output a log message of each full path from the specified starting path.
func (u *Utils) CrawlLogPaths(root string) error
TextToSlug()
The TextToSlug function converts accented characters to their unaccented versions, replaces all non-alphanumeric characters with dashes, trims redundant dashes, and converts the string to lowercase. This approach makes the slug both URL-friendly and human-readable.
func (u *Utils) TextToSlug(input string) string
ForceFileDownload()
ForceFileDownload forces the browser to avoid displaying it in the browser window by setting the Content-Disposition header. It also allows specifying a custom display name for the downloaded file.
func (u *Utils) ForceFileDownload(w http.ResponseWriter, r *http.Request, pathToFile, displayName string)
ReadJSON()
ReadJSON tries to read the body of a request and converts from json into a go data variable.
func (u *Utils) ReadJSON(w http.ResponseWriter, r *http.Request, data interface{}) error
WriteJSON()
WriteJSON takes a response, an httpStatus code, and arbitrary data, then generates and sends json in the http response to the client.
func (u *Utils) WriteJSON(w http.ResponseWriter, httpStatus int, data interface{}, headers ...http.Header) error
ErrorJSON()
ErrorJSON takes an error and optionally an http httpStatus code, then generates and sends a json formatted error http response. If no httpStatus code is passed, http.StatusBadRequest is the defualt used.
func (u *Utils) ErrorJSON(w http.ResponseWriter, err error, httpStatus ...int) error
PushJSONToRemote()
PushJSONToRemote sends arbitrary data to a specified URL as JSON, and returns the response and http status code, or an error if any.
The client parameter is optional. If none is specified, it uses the standard library's http.Client.
func (u *Utils) PushJSONToRemote(uri string, method string, data interface{}, client ...*http.Client) (*http.Response, int, error)
LoadEnvVarsFromFile()
LoadEnvVarsFromFile expects a string represnting the path to the environment variable file. This approach relies on the environment variables file existing in the file system and being readable.
func (u *Utils) LoadEnvVarsFromFile(filename string) error
LoadEnvVarsFromEmbed()
LoadEnvVarsFromEmbed expects a string resulting from having uses Go's //go:embed directive to import an embedded environment variable file.
This approach relies on the environment variables file being embedded directly in the binary, which might not be ideal for sensitive data in some cases.
func (u *Utils) LoadEnvVarsFromEmbed(goEmbedReadFile string) error
UniqueRunes()
UniqueRunes takes a string and converts it to a slice of unique runes. This method preserves the order of the first appearance of runes in the input string. Because Go's rune type handles Unicode characters properly, this solution works correctly even with strings containing non-ASCII characters.
func (u *Utils) UniqueRunes(s string) []rune
ContainsAllRunes()
ContainsAllRunes checks if all runes in a subset slice are contained in set slice. This method correctly handles cases where runes are duplicated, both in the set and subset slices. This works with Unicode characters, as Go's rune type properly supports Unicode.
func (u *Utils) ContainsAllRunes(set, subset []rune) bool
Installation
go get -u github.com/loickreitmann/utils
Usage
See the example test files, or the package doumentation on the Go Package Discovery site.