gopkg.in/easygen.v4@v4.1.0/README.e.md (about) 1 # {{.Name}} 2 3 [](LICENSE) 4 {{template "badge/godoc" .}} 5 {{template "badge/goreport" .}} 6 {{template "badge/travis" .}} 7 [ ](https://codeship.com/projects/135255) 8 9 ## {{toc 5}} 10 11 # {{.Name}} - Easy to use universal code/text generator 12 13 Command `{{.Name}}` is an easy to use universal code/text generator. 14 15 It can be used as a text or html generator for _arbitrary_ purposes with _arbitrary_ data and templates. It is a good [GSL](https://github.com/imatix/gsl) replacement, as it 16 17 - is more easy to define driving data, in form of YML instead of XML 18 - has more powerful template engine that based on Go template. 19 You can also write your own function in Go to customize your template. 20 21 You can even use easygen as a generic Go template testing tool using the `-ts` commandline option, and much more. 22 23 Note this document is for `{{.Name}}` versions 4.0+. For historic versions check out the [Different Versions](#different-versions) section. 24 25 26 ## Usage 27 28 ### $ {{exec "easygen" | color "sh"}} 29 30 ## Install 31 32 ### Install as Debian/Unbuntu package 33 34 35 apt install {{.Name}} 36 37 38 ### Install from source 39 40 go get github.com/go-easygen/easygen/... 41 ls -l $GOPATH/bin 42 43 You should find an `{{.Name}}` executable newly created in there. 44 45 ## Test 46 47 export PATH=$PATH:$GOPATH/bin 48 49 $ easygen $GOPATH/src/github.com/go-easygen/easygen/test/list0 50 The colors are: red, blue, white, . 51 52 cd $GOPATH/src/github.com/go-easygen/easygen 53 54 $ easygen test/list1 55 The quoted colors are: "red", "blue", "white", . 56 57 $ easygen test/listfunc1 test/list0 58 red, blue, white. 59 60 61 And also check out the provided [more examples](https://godoc.org/github.com/go-easygen/easygen#pkg-examples) in the [](https://godoc.org/github.com/go-easygen/easygen) document. 62 63 64 ## Details 65 66 It can be used as a code generator, for example, command line parameter handling code generator, or anything that is structurally repetitive, like the following: 67 68 69 - [Introduction to easygen and its philosophy ](https://suntong.github.io/blogs/2016/01/01/easygen---easy-to-use-universal-code/text-generator) 70 - [Easygen is now coding itself ](https://sfxpt.wordpress.com/2015/07/04/easygen-is-now-coding-itself/) 71 - [Showcasing the power of easygen with ffcvt ](https://sfxpt.wordpress.com/2015/08/02/showcasing-the-power-of-easygen-with-ffcvt/) 72 - [Easygen for HTML mock-up ](https://sfxpt.wordpress.com/2015/07/10/easygen-for-mock-up/) 73 - [Moving beyond code-gen and mock-up, using easygen in real life creating GPT partitions](https://suntong.github.io/blogs/2015/12/26/creating-gpt-partitions-easily-on-the-command-line) 74 75 Ready to get started? Then check out [Getting Started](https://github.com/go-easygen/easygen/wiki/Getting-Started) to start building your way to turn your data into any form, any way you want. 76 77 <a name="clfhcag" /> 78 79 ## Command line flag handling code auto-generation 80 81 [ ](https://suntong.github.io/blogs/) 82 83 As explained above, one practical use of `easygen` is to auto-generating Go code for command line parameter handling, for both [`viper` and `cobra`](https://github.com/suntong/blog/blob/master/GoOptP7-easygen.md), and Go's [built-in `flag` package](https://sfxpt.wordpress.com/2015/07/04/easygen-is-now-coding-itself/). 84 85 86 ### `easygen` itself 87 88 Currently, `easygen`'s command line parameter handling is built on top of Go's built-in `flag` package, and the handling code is entirely generated by `easygen` itself. Thus, showing how `easygen` is handling the command line parameters itself also means showing what functionality the auto-generated command line parameter handling code can do for you. 89 90 Currently, there are three tiers program parameters can be given: 91 92 1. Default values defined within the program, so that program parameters can have meaningful defaults to start with 93 1. Values defined in environment variables 94 1. Values passed from command line 95 96 The latter will have higher priority and will override values defined formerly. I.e., the values from command line will override that in environment variables, which in turn override program defaults. 97 98 We will use the `-ts`, template string, as an example to illustrate. The program defaults is empty, which means using the `.tmpl` template file the same as the `.yaml` data file. We will override that first by environment variable, then from command line, illustrated in next section. 99 100 ### `cli` based 101 102 See, 103 104 [A cookbook on how to jump-start a `cli` based command line handling program](cli-project.md#cookbook) 105 106 ## The `easygen` usage 107 108 ### Command line 109 110 [Check here for more on using `easygen` the command line tool](using_easygen.md). 111 112 ### The library 113 114 The `easygen` is a library as well as a command line tools. Not only it is super easy to use, it is super easy to extend as well. 115 116 The [restructured `easygen`](https://github.com/go-easygen/easygen/issues/10) can now be a building block that people can easily extend, any extra functionalities, or extra feature that it depends on, or any external dependencies are now moved out to sub modules. Thus the library users can now pick and choose exactly what they want from the library. 117 118 - The [egVar package example](http://godoc.org/github.com/go-easygen/easygen/egVar#example-package) shows how to add the variable name manipulation on top of the default library. 119 - The [egCal package example](http://godoc.org/github.com/go-easygen/easygen/egCal#example-package) shows how to add the variable name manipulation and generic calculation functionalities, together with the default functions, all at the same time. 120 121 To put them all together, check out the `easygen`'s `main.go`: 122 123 #### > cmd/easygen/main.go 124 125 ```go 126 package main 127 128 import ( 129 "flag" 130 "os" 131 132 "github.com/go-easygen/easygen" 133 "github.com/go-easygen/easygen/egCal" 134 "github.com/go-easygen/easygen/egVar" 135 ) 136 137 //go:generate sh -v easygen.gen.sh 138 139 //////////////////////////////////////////////////////////////////////////// 140 // Main 141 142 func main() { 143 flag.Usage = Usage 144 flag.Parse() 145 146 // One mandatory non-flag arguments 147 if flag.NArg() < 1 { 148 Usage() 149 } 150 151 tmpl0 := easygen.NewTemplate().Customize() 152 tmpl := tmpl0.Funcs(easygen.FuncDefs()). 153 Funcs(egVar.FuncDefs()).Funcs(egCal.FuncDefs()) 154 155 args := flag.Args() 156 if len(easygen.Opts.TemplateStr) > 0 { 157 easygen.Process0(tmpl, os.Stdout, easygen.Opts.TemplateStr, args...) 158 } else { 159 easygen.Process(tmpl, os.Stdout, args...) 160 } 161 } 162 ``` 163 164 It has been as simple as this up until version 3. I.e., it's quite simple to make use of `easygen` as a package. 165 166 167 ### Different Versions 168 169 The `easygen` has gone through four different versions whose API are a bit different between them. 170 171 To always stay at the latest version, `import` 172 173 "github.com/go-easygen/easygen" 174 175 in your Go code. However, to stay within a certain version, `import` the following package respectively to what you need: 176 177 - V4: "[gopkg.in/easygen.v4](https://gopkg.in/easygen.v4)" 178 - V3: "[gopkg.in/easygen.v3](https://gopkg.in/easygen.v3)" 179 - V2: "[gopkg.in/easygen.v2](https://gopkg.in/easygen.v2)" 180 - V1: "[gopkg.in/easygen.v1](https://gopkg.in/easygen.v1)" 181 182 To see the differences between them, check out 183 184 - [V4 vs V3](https://github.com/go-easygen/easygen/wiki/V4-vs-V3) 185 - [V3 vs V2](https://github.com/go-easygen/easygen/wiki/V3-vs-V2) 186 - [V2 vs V1](https://github.com/go-easygen/easygen/wiki/V2-vs-V1) 187 188 ## Author(s) & Contributor(s) 189 190 Tong SUN 191  192 193 Gerrit Renker 194 https://github.com/grrtrr 195 196 All patches welcome.