paramex

README

paramex

Paramex is a library that binds http request parameters to a Go struct annotated with param.

Description

To extract http parameters (headers, url query values, form values), multiple code lines need to be written in http Handlers.

But, Using Paramex http headers, url query values or form values can be extracted by calling a single function.

Sample code example code to extract request form values using paramex is shown below.

package main

import (
	"fmt"
	"log"
	"net/http"
	"net/url"
	"strings"

	"github.com/senpathi/paramex"
)

type formParams struct {
	Name       string   `param:"name"`
	Age        int      `param:"age"`
	Height     float64  `param:"height"`
	Married    bool     `param:"married"`
	OtherNames []string `param:"other_names"`
}

func main() {
	reqForm := url.Values{}
	reqForm.Set(`name`, `form_name`)
	reqForm.Set(`age`, `50`)
	reqForm.Set(`height`, `1.72`)
	reqForm.Set(`married`, `true`)
	reqForm[`other_names`] = []string{`form_test`, `form_example`}

	req, err := http.NewRequest(`POST`, `https://nipuna.lk`, strings.NewReader(reqForm.Encode()))
	if err != nil {
		log.Fatalln(err)
	}
	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

	forms := formParams{}
	extractor := paramex.NewParamExtractor()

	err = extractor.ExtractForms(&forms, req)
	if err != nil {
		log.Fatalln(fmt.Errorf(`error extracting forms due to %v`, err))
	}

	fmt.Println(fmt.Sprintf(`request forms := %v`, forms))
	//Output : request forms := {form_name 50 1.72 true [form_test form_example]}
}

Examples codes to extract http headers, url query values and form values are implemented in example directory.

Supported parameter types

• string
• bool
• int32
• int
• int64
• float32
• float64
• uuid.UUID
• []string (only for form values and query values)

Documentation

Overview

Package paramex is a library that binds http request parameters to a Go struct annotated with param.

Description

To extract http parameters (headers, url query values, form values), multiple code lines need to be written in http Handlers.

But, Using Paramex http headers, url query values or form values can be extracted by calling a single function.

Sample code example code to extract request form values using paramex is shown below.

package main

import (
	"fmt"
	"log"
	"net/http"
	"net/url"
	"strings"

	"github.com/senpathi/paramex"
)

type formParams struct {
	Name       string   `param:"name"`
	Age        int      `param:"age"`
	Height     float64  `param:"height"`
	Married    bool     `param:"married"`
	OtherNames []string `param:"other_names"`
}

func main() {
	reqForm := url.Values{}
	reqForm.Set(`name`, `form_name`)
	reqForm.Set(`age`, `50`)
	reqForm.Set(`height`, `1.72`)
	reqForm.Set(`married`, `true`)
	reqForm[`other_names`] = []string{`form_test`, `form_example`}

	req, err := http.NewRequest(`POST`, `https://nipuna.lk`, strings.NewReader(reqForm.Encode()))
	if err != nil {
		log.Fatalln(err)
	}
	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

	forms := formParams{}
	extractor := paramex.NewParamExtractor()

	err = extractor.ExtractForms(&forms, req)
	if err != nil {
		log.Fatalln(fmt.Errorf(`error extracting forms due to %v`, err))
	}

	fmt.Println(fmt.Sprintf(`request forms := %v`, forms))
	//Output : request forms := {form_name 50 1.72 true [form_test form_example]}
}

Examples codes to extract http headers, url query values and form values are implemented in https://github.com/senpathi/paramex/tree/master/example directory.

Supported parameter types

• string
• bool
• int32
• int
• int64
• float32
• float64
• []string (only for form values and query values)
• https://github.com/google/uuid

Index

• type ErrorNotAssignable
• type ErrorUnSupportedParamType
• type ErrorUnSupportedType
• type ErrorUnmarshalType
• type Extractor
  • func NewParamExtractor() Extractor

Types

type ErrorNotAssignable

type ErrorNotAssignable struct {
	// contains filtered or unexported fields
}

ErrorNotAssignable created when sent interface to extract is not assignable. Not a reference to a Go struct

type ErrorUnSupportedParamType

type ErrorUnSupportedParamType struct {
	// contains filtered or unexported fields
}

ErrorUnSupportedParamType created when trying to extract unsupported parameter type

type ErrorUnSupportedType

type ErrorUnSupportedType struct {
	// contains filtered or unexported fields
}

ErrorUnSupportedType created when sent reference is not a Go struct type reference

type ErrorUnmarshalType

type ErrorUnmarshalType struct {
	// contains filtered or unexported fields
}

ErrorUnmarshalType created when trying to marshal different type value to another type variable

type Extractor

type Extractor interface {
	// ExtractHeaders extract http headers from sent request and binds to `v`
	// `v` should be a Go struct reference
	ExtractHeaders(v interface{}, req *http.Request) error

	// ExtractQueries extract http url parameters from sent request and binds to v
	// `v` should be a Go struct reference
	ExtractQueries(v interface{}, req *http.Request) error

	// ExtractForms extract http form values from sent request and binds to v
	// `v` should be a Go struct reference
	ExtractForms(v interface{}, req *http.Request) error
}

The Extractor interface is implemented to extract http request headers, form values and url query values

func NewParamExtractor

func NewParamExtractor() Extractor

NewParamExtractor returns an Extractor which extract req.Header, req.FormValue, req.URL.Query values and binds them to a Go struct