mirror of
				https://github.com/gohugoio/hugo.git
				synced 2024-05-11 05:54:58 +00:00 
			
		
		
		
	The variable scope in the Go templates makes it hard, if possible at all, to write templates with counter variables or similar state. This commit fixes that by adding a writable context to Node, backed by a map: Scratch. This context has three methods, Get, Set and Add. The Add is tailored for counter variables, but can be used for any built-in numeric values or strings.
		
			
				
	
	
		
			58 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			58 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
// Copyright © 2013-14 Steve Francia <spf@spf13.com>.
 | 
						|
//
 | 
						|
// Licensed under the Simple Public License, Version 2.0 (the "License");
 | 
						|
// you may not use this file except in compliance with the License.
 | 
						|
// You may obtain a copy of the License at
 | 
						|
// http://opensource.org/licenses/Simple-2.0
 | 
						|
//
 | 
						|
// Unless required by applicable law or agreed to in writing, software
 | 
						|
// distributed under the License is distributed on an "AS IS" BASIS,
 | 
						|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 | 
						|
// See the License for the specific language governing permissions and
 | 
						|
// limitations under the License.
 | 
						|
 | 
						|
package hugolib
 | 
						|
 | 
						|
import (
 | 
						|
	"github.com/spf13/hugo/helpers"
 | 
						|
)
 | 
						|
 | 
						|
// Scratch is a writable context used for stateful operations in Page/Node rendering.
 | 
						|
type Scratch struct {
 | 
						|
	values map[string]interface{}
 | 
						|
}
 | 
						|
 | 
						|
// Add will add (using the + operator) the addend to the existing addend (if found).
 | 
						|
// Supports numeric values and strings.
 | 
						|
func (c *Scratch) Add(key string, newAddend interface{}) (string, error) {
 | 
						|
	var newVal interface{}
 | 
						|
	existingAddend, found := c.values[key]
 | 
						|
	if found {
 | 
						|
		var err error
 | 
						|
		newVal, err = helpers.DoArithmetic(existingAddend, newAddend, '+')
 | 
						|
		if err != nil {
 | 
						|
			return "", err
 | 
						|
		}
 | 
						|
	} else {
 | 
						|
		newVal = newAddend
 | 
						|
	}
 | 
						|
	c.values[key] = newVal
 | 
						|
	return "", nil // have to return something to make it work with the Go templates
 | 
						|
}
 | 
						|
 | 
						|
// Set stores a value with the given key in the Node context.
 | 
						|
// This value can later be retrieved with Get.
 | 
						|
func (c *Scratch) Set(key string, value interface{}) string {
 | 
						|
	c.values[key] = value
 | 
						|
	return ""
 | 
						|
}
 | 
						|
 | 
						|
// Get returns a value previously set by Add or Set
 | 
						|
func (c *Scratch) Get(key string) interface{} {
 | 
						|
	return c.values[key]
 | 
						|
}
 | 
						|
 | 
						|
func newScratch() *Scratch {
 | 
						|
	return &Scratch{values: make(map[string]interface{})}
 | 
						|
}
 |