-
-
Notifications
You must be signed in to change notification settings - Fork 270
/
tags_macro.go
159 lines (128 loc) · 3.91 KB
/
tags_macro.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
package pongo2
import (
"bytes"
"fmt"
)
const maxMacroDepth = 1000
type tagMacroNode struct {
position *Token
name string
argsOrder []string
args map[string]IEvaluator
exported bool
wrapper *NodeWrapper
}
func (node *tagMacroNode) Execute(ctx *ExecutionContext, writer TemplateWriter) *Error {
ctx.Private[node.name] = func(args ...*Value) (*Value, error) {
ctx.macroDepth++
defer func() {
ctx.macroDepth--
}()
if ctx.macroDepth > maxMacroDepth {
return nil, ctx.Error(fmt.Sprintf("maximum recursive macro call depth reached (max is %v)", maxMacroDepth), node.position)
}
return node.call(ctx, args...)
}
return nil
}
func (node *tagMacroNode) call(ctx *ExecutionContext, args ...*Value) (*Value, error) {
argsCtx := make(Context)
for k, v := range node.args {
if v == nil {
// User did not provided a default value
argsCtx[k] = nil
} else {
// Evaluate the default value
valueExpr, err := v.Evaluate(ctx)
if err != nil {
ctx.Logf(err.Error())
return AsSafeValue(""), err
}
argsCtx[k] = valueExpr
}
}
if len(args) > len(node.argsOrder) {
// Too many arguments, we're ignoring them and just logging into debug mode.
err := ctx.Error(fmt.Sprintf("Macro '%s' called with too many arguments (%d instead of %d).",
node.name, len(args), len(node.argsOrder)), nil).updateFromTokenIfNeeded(ctx.template, node.position)
return AsSafeValue(""), err
}
// Make a context for the macro execution
macroCtx := NewChildExecutionContext(ctx)
// Register all arguments in the private context
macroCtx.Private.Update(argsCtx)
for idx, argValue := range args {
macroCtx.Private[node.argsOrder[idx]] = argValue.Interface()
}
var b bytes.Buffer
err := node.wrapper.Execute(macroCtx, &b)
if err != nil {
return AsSafeValue(""), err.updateFromTokenIfNeeded(ctx.template, node.position)
}
return AsSafeValue(b.String()), nil
}
func tagMacroParser(doc *Parser, start *Token, arguments *Parser) (INodeTag, *Error) {
macroNode := &tagMacroNode{
position: start,
args: make(map[string]IEvaluator),
}
nameToken := arguments.MatchType(TokenIdentifier)
if nameToken == nil {
return nil, arguments.Error("Macro-tag needs at least an identifier as name.", nil)
}
macroNode.name = nameToken.Val
if arguments.MatchOne(TokenSymbol, "(") == nil {
return nil, arguments.Error("Expected '('.", nil)
}
for arguments.Match(TokenSymbol, ")") == nil {
argNameToken := arguments.MatchType(TokenIdentifier)
if argNameToken == nil {
return nil, arguments.Error("Expected argument name as identifier.", nil)
}
macroNode.argsOrder = append(macroNode.argsOrder, argNameToken.Val)
if arguments.Match(TokenSymbol, "=") != nil {
// Default expression follows
argDefaultExpr, err := arguments.ParseExpression()
if err != nil {
return nil, err
}
macroNode.args[argNameToken.Val] = argDefaultExpr
} else {
// No default expression
macroNode.args[argNameToken.Val] = nil
}
if arguments.Match(TokenSymbol, ")") != nil {
break
}
if arguments.Match(TokenSymbol, ",") == nil {
return nil, arguments.Error("Expected ',' or ')'.", nil)
}
}
if arguments.Match(TokenKeyword, "export") != nil {
macroNode.exported = true
}
if arguments.Remaining() > 0 {
return nil, arguments.Error("Malformed macro-tag.", nil)
}
// Body wrapping
wrapper, endargs, err := doc.WrapUntilTag("endmacro")
if err != nil {
return nil, err
}
macroNode.wrapper = wrapper
if endargs.Count() > 0 {
return nil, endargs.Error("Arguments not allowed here.", nil)
}
if macroNode.exported {
// Now register the macro if it wants to be exported
_, has := doc.template.exportedMacros[macroNode.name]
if has {
return nil, doc.Error(fmt.Sprintf("another macro with name '%s' already exported", macroNode.name), start)
}
doc.template.exportedMacros[macroNode.name] = macroNode
}
return macroNode, nil
}
func init() {
RegisterTag("macro", tagMacroParser)
}