github.com/zhongdalu/gf@v1.0.0/g/os/gview/gview.go

// Copyright 2017 gf Author(https://github.com/zhongdalu/gf). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/zhongdalu/gf.

// Package gview implements a template engine based on text/template.
package gview

import (
	"bytes"
	"errors"
	"fmt"
	"github.com/zhongdalu/gf"
	"github.com/zhongdalu/gf/g/container/garray"
	"github.com/zhongdalu/gf/g/internal/cmdenv"
	"github.com/zhongdalu/gf/g/os/gfile"
	"github.com/zhongdalu/gf/g/os/glog"
	"github.com/zhongdalu/gf/g/os/gspath"
	"sync"
)

// View object for template engine.
type View struct {
	mu         sync.RWMutex
	paths      *garray.StringArray    // Searching path array.
	data       map[string]interface{} // Global template variables.
	funcMap    map[string]interface{} // Global template function map.
	delimiters []string               // Customized template delimiters.
}

// Params is type for template params.
type Params = map[string]interface{}

// FuncMap is type for custom template functions.
type FuncMap = map[string]interface{}

// Default view object.
var defaultViewObj *View

// checkAndInitDefaultView checks and initializes the default view object.
// The default view object will be initialized just once.
func checkAndInitDefaultView() {
	if defaultViewObj == nil {
		defaultViewObj = New()
	}
}

// ParseContent parses the template content directly using the default view object
// and returns the parsed content.
func ParseContent(content string, params Params) (string, error) {
	checkAndInitDefaultView()
	return defaultViewObj.ParseContent(content, params)
}

// New returns a new view object.
// The parameter <path> specifies the template directory path to load template files.
func New(path ...string) *View {
	view := &View{
		paths:      garray.NewStringArray(),
		data:       make(map[string]interface{}),
		funcMap:    make(map[string]interface{}),
		delimiters: make([]string, 2),
	}
	if len(path) > 0 && len(path[0]) > 0 {
		view.SetPath(path[0])
	} else {
		// Customized dir path from env/cmd.
		if envPath := cmdenv.Get("gf.gview.path").String(); envPath != "" {
			if gfile.Exists(envPath) {
				view.SetPath(envPath)
			} else {
				if errorPrint() {
					glog.Errorf("Template directory path does not exist: %s", envPath)
				}
			}
		} else {
			// Dir path of working dir.
			view.SetPath(gfile.Pwd())
			// Dir path of binary.
			if selfPath := gfile.SelfDir(); selfPath != "" && gfile.Exists(selfPath) {
				view.AddPath(selfPath)
			}
			// Dir path of main package.
			if mainPath := gfile.MainPkgPath(); mainPath != "" && gfile.Exists(mainPath) {
				view.AddPath(mainPath)
			}
		}
	}
	view.SetDelimiters("{{", "}}")
	// default build-in variables.
	view.data["GF"] = map[string]interface{}{
		"version": gf.VERSION,
	}
	// default build-in functions.
	view.BindFunc("eq", view.funcEq)
	view.BindFunc("ne", view.funcNe)
	view.BindFunc("lt", view.funcLt)
	view.BindFunc("le", view.funcLe)
	view.BindFunc("gt", view.funcGt)
	view.BindFunc("ge", view.funcGe)
	view.BindFunc("text", view.funcText)
	view.BindFunc("html", view.funcHtmlEncode)
	view.BindFunc("htmlencode", view.funcHtmlEncode)
	view.BindFunc("htmldecode", view.funcHtmlDecode)
	view.BindFunc("url", view.funcUrlEncode)
	view.BindFunc("urlencode", view.funcUrlEncode)
	view.BindFunc("urldecode", view.funcUrlDecode)
	view.BindFunc("date", view.funcDate)
	view.BindFunc("substr", view.funcSubStr)
	view.BindFunc("strlimit", view.funcStrLimit)
	view.BindFunc("compare", view.funcCompare)
	view.BindFunc("hidestr", view.funcHideStr)
	view.BindFunc("highlight", view.funcHighlight)
	view.BindFunc("toupper", view.funcToUpper)
	view.BindFunc("tolower", view.funcToLower)
	view.BindFunc("nl2br", view.funcNl2Br)
	view.BindFunc("include", view.funcInclude)
	return view
}

// SetPath sets the template directory path for template file search.
// The parameter <path> can be absolute or relative path, but absolute path is suggested.
func (view *View) SetPath(path string) error {
	// Absolute path.
	realPath := gfile.RealPath(path)
	if realPath == "" {
		// Relative path.
		view.paths.RLockFunc(func(array []string) {
			for _, v := range array {
				if path, _ := gspath.Search(v, path); path != "" {
					realPath = path
					break
				}
			}
		})
	}
	// Path not exist.
	if realPath == "" {
		buffer := bytes.NewBuffer(nil)
		if view.paths.Len() > 0 {
			buffer.WriteString(fmt.Sprintf("[gview] SetPath failed: cannot find directory \"%s\" in following paths:", path))
			view.paths.RLockFunc(func(array []string) {
				for k, v := range array {
					buffer.WriteString(fmt.Sprintf("\n%d. %s", k+1, v))
				}
			})
		} else {
			buffer.WriteString(fmt.Sprintf(`[gview] SetPath failed: path "%s" does not exist`, path))
		}
		err := errors.New(buffer.String())
		if errorPrint() {
			glog.Error(err)
		}
		return err
	}
	// Should be a directory.
	if !gfile.IsDir(realPath) {
		err := errors.New(fmt.Sprintf(`[gview] SetPath failed: path "%s" should be directory type`, path))
		if errorPrint() {
			glog.Error(err)
		}
		return err
	}
	// Repeated path check.
	if view.paths.Search(realPath) != -1 {
		return nil
	}
	view.paths.Clear()
	view.paths.Append(realPath)
	//glog.Debug("[gview] SetPath:", realPath)
	return nil
}

// AddPath adds a absolute or relative path to the search paths.
func (view *View) AddPath(path string) error {
	// Absolute path.
	realPath := gfile.RealPath(path)
	if realPath == "" {
		// Relative path.
		view.paths.RLockFunc(func(array []string) {
			for _, v := range array {
				if path, _ := gspath.Search(v, path); path != "" {
					realPath = path
					break
				}
			}
		})
	}
	// Path not exist.
	if realPath == "" {
		buffer := bytes.NewBuffer(nil)
		if view.paths.Len() > 0 {
			buffer.WriteString(fmt.Sprintf("[gview] AddPath failed: cannot find directory \"%s\" in following paths:", path))
			view.paths.RLockFunc(func(array []string) {
				for k, v := range array {
					buffer.WriteString(fmt.Sprintf("\n%d. %s", k+1, v))
				}
			})
		} else {
			buffer.WriteString(fmt.Sprintf(`[gview] AddPath failed: path "%s" does not exist`, path))
		}
		err := errors.New(buffer.String())
		if errorPrint() {
			glog.Error(err)
		}
		return err
	}
	// realPath should be type of folder.
	if !gfile.IsDir(realPath) {
		err := errors.New(fmt.Sprintf(`[gview] AddPath failed: path "%s" should be directory type`, path))
		if errorPrint() {
			glog.Error(err)
		}
		return err
	}
	// Repeated path check.
	if view.paths.Search(realPath) != -1 {
		return nil
	}
	view.paths.Append(realPath)
	return nil
}