google-cloud-go-transaction-generator

Generates common transaction functions for google cloude datastore models. For use with google-cloud-go datastore package.

Generates functions for:

• get
• add
• delete
• update
• query by property

Usage

Install

go install github.com/codegp/google-cloud-go-transaction-generator

Make an alias (Optional, Recommended)

This package name is ridiculously long. I recommend you add an alias to your bash profile so you don't have to type google-cloud-go-transaction-generator everytime you want to run this thing. I use gcgtg, which is used in the examples below.

Define a config.yaml

outputPackage: outputpackage # package in which the generated code will live
receiver: MyClient # struct that has a DatastoreClient getter, which returns a *datastore.Client
generators:
  - modelPackageName: exampleModels
    modelsImportPath: github.com/example/exampleModels
    models:
      - ModelA
      - ModelB
  - modelPackageName: demoModels
    modelsImportPath: github.com/demo/demoModels
    models:
      - ModelC
      - ModelD
    outputDir: "./customOutputDir" # custom output directory for this set of models
    outputPackage: "customoutputpackage" # custom output package for this set of models
outputDir: "./defaultOutputDir"

Generate the codez

gcgtg ./config.yaml

Example

gcgtg ./example/exampleConfig.yaml

Generates:

package examplepackage

import (
	"fmt"

	"cloud.google.com/go/datastore"
	"github.com/codegp/google-cloud-go-transaction-generator/examplemodel"

	"golang.org/x/net/context"
)

// GetExampleModel retrieves a ExampleModel by its ID.
func (c *ExampleReceiver) GetExampleModel(id int64) (*examplemodel.ExampleModel, error) {
	ctx := context.Background()
	k := datastore.NewKey(ctx, "ExampleModel", "", id, nil)
	ExampleModel := &examplemodel.ExampleModel{}
	if err := c.DatastoreClient().Get(ctx, k, ExampleModel); err != nil {
		return nil, fmt.Errorf("datastoredb: could not get ExampleModel: %v", err)
	}
	ExampleModel.ID = id
	return ExampleModel, nil
}

// AddExampleModel saves a given ExampleModel, assigning it a new ID.
func (c *ExampleReceiver) AddExampleModel(b *examplemodel.ExampleModel) (*examplemodel.ExampleModel, error) {
	ctx := context.Background()
	k := datastore.NewIncompleteKey(ctx, "ExampleModel", nil)
	k, err := c.DatastoreClient().Put(ctx, k, b)
	if err != nil {
		return nil, fmt.Errorf("datastoredb: could not put ExampleModel: %v", err)
	}
	b.ID = k.ID()
	return b, nil
}

// DeleteExampleModel removes a given ExampleModel by its ID.
func (c *ExampleReceiver) DeleteExampleModel(id int64) error {
	ctx := context.Background()
	k := datastore.NewKey(ctx, "ExampleModel", "", id, nil)
	if err := c.DatastoreClient().Delete(ctx, k); err != nil {
		return fmt.Errorf("datastoredb: could not delete ExampleModel: %v", err)
	}
	return nil
}

// UpdateExampleModel updates the entry for a given ExampleModel.
func (c *ExampleReceiver) UpdateExampleModel(b *examplemodel.ExampleModel) error {
	ctx := context.Background()
	k := datastore.NewKey(ctx, "ExampleModel", "", b.ID, nil)
	if _, err := c.DatastoreClient().Put(ctx, k, b); err != nil {
		return fmt.Errorf("datastoredb: could not update ExampleModel: %v", err)
	}
	return nil
}

// ListExampleModels returns a list of ExampleModels
func (c *ExampleReceiver) ListExampleModels() ([]*examplemodel.ExampleModel, error) {
	ctx := context.Background()
	ExampleModels := make([]*examplemodel.ExampleModel, 0)
	q := datastore.NewQuery("ExampleModel")

	keys, err := c.DatastoreClient().GetAll(ctx, q, &ExampleModels)

	if err != nil {
		return nil, fmt.Errorf("datastoredb: could not list ExampleModels: %v", err)
	}

	for i, k := range keys {
		ExampleModels[i].ID = k.ID()
	}

	return ExampleModels, nil
}

//  QueryExampleModelsByProp
func (c *ExampleReceiver) QueryExampleModelsByProp(propName, value string) (*examplemodel.ExampleModel, error) {
	ctx := context.Background()
	ExampleModels := make([]*examplemodel.ExampleModel, 0)
	q := datastore.NewQuery("ExampleModel").Filter(fmt.Sprintf("%s =", propName), value)

	keys, err := c.DatastoreClient().GetAll(ctx, q, &ExampleModels)

	if err != nil {
		return nil, fmt.Errorf("datastoredb: could not list ExampleModels: %v", err)
	}

	if len(ExampleModels) == 0 {
		return nil, nil
	}

	ExampleModels[0].ID = keys[0].ID()
	return ExampleModels[0], nil
}

Bind data?

To generate the bindata.go file, which embeds the template file into the go source code you must install go-bindata. Read more here

The template data must be binded to distribute the tool without any template dependencies.

Anytime the template is changed you must run:

go-bindata templates/modeltemplate.go.tmpl