filter.go

Documentation: github.com/noirbizarre/gonja/builtins/statements

     1  package statements
     2  
     3  import (
     4  	// "bytes"
     5  
     6  	// "github.com/noirbizarre/gonja/exec"
     7  	"fmt"
     8  	"strings"
     9  
    10  	"github.com/pkg/errors"
    11  
    12  	"github.com/noirbizarre/gonja/exec"
    13  	"github.com/noirbizarre/gonja/nodes"
    14  	"github.com/noirbizarre/gonja/parser"
    15  	"github.com/noirbizarre/gonja/tokens"
    16  )
    17  
    18  type FilterStmt struct {
    19  	position    *tokens.Token
    20  	bodyWrapper *nodes.Wrapper
    21  	filterChain []*nodes.FilterCall
    22  }
    23  
    24  func (stmt *FilterStmt) Position() *tokens.Token { return stmt.position }
    25  func (stmt *FilterStmt) String() string {
    26  	t := stmt.Position()
    27  	return fmt.Sprintf("FilterStmt(Line=%d Col=%d)", t.Line, t.Col)
    28  }
    29  
    30  func (node *FilterStmt) Execute(r *exec.Renderer, tag *nodes.StatementBlock) error {
    31  	var out strings.Builder
    32  	sub := r.Inherit()
    33  	sub.Out = &out
    34  	// temp := bytes.NewBuffer(make([]byte, 0, 1024)) // 1 KiB size
    35  
    36  	err := sub.ExecuteWrapper(node.bodyWrapper)
    37  	if err != nil {
    38  		return err
    39  	}
    40  
    41  	value := exec.AsValue(out.String())
    42  
    43  	for _, call := range node.filterChain {
    44  		value = r.Evaluator().ExecuteFilter(call, value)
    45  		if value.IsError() {
    46  			return errors.Wrapf(value, `Unable to apply filter %s (Line: %d Col: %d, near %s`,
    47  				call.Name, call.Token.Line, call.Token.Col, call.Token.Val)
    48  		}
    49  	}
    50  
    51  	r.WriteString(value.String())
    52  
    53  	return nil
    54  }
    55  
    56  func filterParser(p *parser.Parser, args *parser.Parser) (nodes.Statement, error) {
    57  	stmt := &FilterStmt{
    58  		position: p.Current(),
    59  	}
    60  
    61  	wrapper, _, err := p.WrapUntil("endfilter")
    62  	if err != nil {
    63  		return nil, err
    64  	}
    65  	stmt.bodyWrapper = wrapper
    66  
    67  	for !args.End() {
    68  		filterCall, err := args.ParseFilter()
    69  		if err != nil {
    70  			return nil, err
    71  		}
    72  
    73  		stmt.filterChain = append(stmt.filterChain, filterCall)
    74  
    75  		if args.Match(tokens.Pipe) == nil {
    76  			break
    77  		}
    78  	}
    79  
    80  	if !args.End() {
    81  		return nil, p.Error("Malformed filter-tag args.", nil)
    82  	}
    83  
    84  	return stmt, nil
    85  }
    86  
    87  func init() {
    88  	All.Register("filter", filterParser)
    89  }
    90
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