| // Copyright 2018 The CUE Authors |
| // |
| // Licensed under the Apache 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://www.apache.org/licenses/LICENSE-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 cmd |
| |
| import ( |
| "encoding/json" |
| "fmt" |
| "io" |
| |
| "github.com/spf13/cobra" |
| |
| "cuelang.org/go/cue" |
| "cuelang.org/go/cue/ast" |
| "cuelang.org/go/cue/parser" |
| "cuelang.org/go/pkg/encoding/yaml" |
| ) |
| |
| // newExportCmd creates and export command |
| func newExportCmd(c *Command) *cobra.Command { |
| cmd := &cobra.Command{ |
| Use: "export", |
| Short: "output data in a standard format", |
| Long: `export evaluates the configuration found in the current |
| directory and prints the emit value to stdout. |
| |
| Examples: |
| Evaluated and emit |
| |
| # a single file |
| cue export config.cue |
| |
| # multiple files: these are combined at the top-level. Order doesn't matter. |
| cue export file1.cue foo/file2.cue |
| |
| # all files within the "mypkg" package: this includes all files in the |
| # current directory and its ancestor directories that are marked with the |
| # same package. |
| cue export -p cloud |
| |
| # the -p flag can be omitted if the directory only contains files for |
| # the "mypkg" package. |
| cue export |
| |
| Emit value: |
| For CUE files, the generated configuration is derived from the top-level |
| single expression, the emit value. For example, the file |
| |
| // config.cue |
| arg1: 1 |
| arg2: "my string" |
| |
| { |
| a: arg1 |
| b: arg2 |
| } |
| |
| yields the following JSON: |
| |
| { |
| "a": 1, |
| "b", "my string" |
| } |
| |
| In absence of arguments, the current directory is loaded as a package instance. |
| A package instance for a directory contains all files in the directory and its |
| ancestor directories, up to the module root, belonging to the same package. |
| If the package is not explicitly defined by the '-p' flag, it must be uniquely |
| defined by the files in the current directory. |
| |
| |
| Formats |
| The following formats are recognized: |
| |
| json output as JSON |
| Outputs any CUE value. |
| |
| text output as raw text |
| The evaluated value must be of type string. |
| `, |
| |
| RunE: mkRunE(c, runExport), |
| } |
| flagMedia.Add(cmd) |
| cmd.Flags().Bool(string(flagEscape), false, "use HTML escaping") |
| |
| cmd.Flags().StringArrayP(string(flagExpression), "e", nil, "export this expression only") |
| |
| cmd.Flags().StringArrayP(string(flagTags), "t", nil, |
| "set the value of a tagged field") |
| |
| return cmd |
| } |
| |
| func runExport(cmd *Command, args []string) error { |
| instances := buildFromArgs(cmd, args) |
| w := cmd.OutOrStdout() |
| |
| var exprs []ast.Expr |
| for _, e := range flagExpression.StringArray(cmd) { |
| expr, err := parser.ParseExpr("<expression flag>", e) |
| if err != nil { |
| return err |
| } |
| exprs = append(exprs, expr) |
| } |
| |
| count := 0 |
| |
| for _, inst := range instances { |
| root := inst.Value() |
| if exprs == nil { |
| err := exportValue(cmd, w, root, count) |
| exitIfErr(cmd, inst, err, true) |
| count++ |
| continue |
| } |
| for _, e := range exprs { |
| v := inst.Eval(e) |
| exitIfErr(cmd, inst, v.Err(), true) |
| err := exportValue(cmd, w, v, count) |
| count++ |
| exitIfErr(cmd, inst, err, true) |
| } |
| } |
| return nil |
| } |
| |
| func exportValue(cmd *Command, w io.Writer, v cue.Value, i int) error { |
| switch media := flagMedia.String(cmd); media { |
| case "json": |
| return outputJSON(cmd, w, v) |
| case "text": |
| return outputText(w, v) |
| case "yaml": |
| return outputYAML(w, v, i) |
| default: |
| return fmt.Errorf("export: unknown format %q", media) |
| } |
| } |
| |
| func outputJSON(cmd *Command, w io.Writer, v cue.Value) error { |
| e := json.NewEncoder(w) |
| e.SetIndent("", " ") |
| e.SetEscapeHTML(flagEscape.Bool(cmd)) |
| |
| err := e.Encode(v) |
| if err != nil { |
| if x, ok := err.(*json.MarshalerError); ok { |
| err = x.Err |
| } |
| return err |
| } |
| return nil |
| } |
| |
| func outputText(w io.Writer, v cue.Value) error { |
| str, err := v.String() |
| if err != nil { |
| return err |
| } |
| _, err = fmt.Fprint(w, str) |
| return err |
| } |
| |
| func outputYAML(w io.Writer, v cue.Value, i int) error { |
| if i > 0 { |
| fmt.Fprintln(w, "---") |
| } |
| str, err := yaml.Marshal(v) |
| if err != nil { |
| return err |
| } |
| _, err = fmt.Fprint(w, str) |
| return err |
| } |