# Template Expressions Many of command/assertion parameters accept templates. So you can use template variables and expressions. For example, `page.goto("https://github.com/{{ USER }}/puppetry/")` or `TARGET.type("name{{ counter() }}")` ## Template variables By using **Settings/Template Variables** panel we can define a set of variables per environment. For an instance, we can declare a separate target app URL for every environment (test.acme.com, stage.acme.com, [www.acme.com](http://www.acme.com)). Before running/exporting test project we specify the desired environment and the corresponding template tags will be replaced with the value (URL) given for that environment. ### Managing Variables To edit template variables click on **Project/Template variables** in the main menu: ![Template variables in the Project menu](https://3461068122-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LdyKJ-zzeS2hB7DF04J%2F-LuIbs7-qh-OBvg6QpLN%2F-LuIcC3Jv-ERr6Qi8nGZ%2Ftemplate-variables.png?alt=media\&token=41cb881a-0d9a-468d-9e1b-31c1def111d1) Under the table Template variables you will find a manageable table with variables (by default it's empty): ![Template variables panel](https://3461068122-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LdyKJ-zzeS2hB7DF04J%2F-LuIbs7-qh-OBvg6QpLN%2F-LuIdHUkW1TsYFmUsRaH%2Ftemplate-vars2.png?alt=media\&token=c9c670a4-62ac-44e8-973d-eeb01e2ae970) You can use this UI the same way to do with targets, suits, and test cases. The difference is that the displayed variables belong to the selected environment: ![Selecting destination environment](https://3461068122-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LdyKJ-zzeS2hB7DF04J%2F-LhKRkJBUuFiu8R0CcwS%2F-LhKRoSTVQCnEoU-Pv-y%2Fp2-variables-env-select.png?alt=media\&token=6dcd95a2-23ed-4e29-a987-bd91c9d24ef3) As you add a new variable let's say to **test** environment it appears in all available environments. But when you update it's value, the value stays unique per environment. Also note the **edit** action link next to the environment selector. When you click it you get a modal window where you can manage the list of environments: ![Editing environments](https://3461068122-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LdyKJ-zzeS2hB7DF04J%2F-LuIbs7-qh-OBvg6QpLN%2F-LuIdWJ0i9h6hzKkP17K%2Ftemplate-vars4.png?alt=media\&token=d4ffc650-b0d9-4cf6-b470-db57fdbe56ec) After we assigned the variables and running the tests (or exporting them for CI) in the modal window we can choose what environment we target: ![Destinating test run for a given environment](https://3461068122-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LdyKJ-zzeS2hB7DF04J%2F-LuIdb0BIentuQ_Ka4Zl%2F-LuIe8OA-vp_8rMzfdJT%2Ftemplate-vars5.png?alt=media\&token=2555f1b0-d0af-437c-bb17-13d55a685ac2) ### Template Syntax #### Syntax ``` {{ VARIABLE_NAME }} ``` The tag makes Puppetry injecting the variable value assigned for the selected environment into the container string #### Examples ``` {{ BASE_URL }}/api/{{ API_VERSION }}/method ``` {% hint style="info" %} Template variables can be also assigned dynamically. E.g. you can use `page.assignVar` to define a variable by using expressions or `page.assignVarRemotely` to define a variable by using REST API ([learn more](https://docs.puppetry.app/testing-emails)). {% endhint %} ## Template Expressions Template expressions are basically functions that we may want to use for building template string. Test step parameters supporting templates provided with a helper widget, which you can you to autofill the field: ![Template helper widget](https://3461068122-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LdyKJ-zzeS2hB7DF04J%2F-LhKSWMFwMhSNQszyGo2%2F-LhKU2k4JJRqBMrO4ovS%2FP2-template-helper.png?alt=media\&token=4f290e9c-453c-405c-ba98-438ff1ad74e5) ### Environment Variables #### Syntax ``` {{ env( NAME ) }} ``` Function returns system [environment variable](https://en.wikipedia.org/wiki/Environment_variable) by a given name #### Examples ``` {{ env( "SECRET" ) }} ``` ### Counter #### Syntax ``` {{ counter() }} ``` Function increments every time it called, but is unique per command/assertion #### Examples ``` joe.{{ counter() }}@acme.com ``` This template resolves in email addresses , and so on ### Uniqid #### Syntax ``` {{ uniqid() }} ``` Function generates a unique id like `8fzk2g5fpkb` #### Examples ``` {{ uniqid() }} ``` ### Iterate #### Syntax ``` {{ iterate( LIST ) }} ``` Function iterates through a given list. It starts from the beginning as it reaches the end #### Examples ``` {{ iterate(["sansas@got.com", "yarag@got.com", "gendryb@got.com"]) }} ``` This template resolves in , , , , ... ### Random #### Syntax ``` {{ random( LIST ) }} ``` Function picks a random value out of a given list. #### Examples ``` {{ random(["sansas@got.com", "yarag@got.com", "gendryb@got.com"]) }} ``` ### HtmlOf #### Syntax ``` {{ htmlOf( TARGET ) }} ``` Function extracts content (innerHTML) of a given TARGET. #### Examples ``` {{ htmlOf("FOO") }} ``` ### AttributeOf #### Syntax ``` {{ attributeOf( TARGET, ATTRIBUTE_NAME ) }} ``` Function retrieve attribute value of a given TARGET. #### Examples ``` {{ attributeOf("FOO", "href") }} ``` ### PropertyOf #### Syntax ``` {{ propertyOf( TARGET, PROPERTY_NAME ) }} ``` Function retrieve property value of a given TARGET. #### Examples ``` {{ propertyOf("FOO", "checked") }} ``` ### Faker #### Syntax ``` {{ fake( FAKER_METHOD, LOCALE ) }} ``` Function generates dummy data, by using [Faker.js methods](https://github.com/marak/Faker.js) #### Examples ``` {{ faker("address.streetSuffix", "en_GB") }} ``` ### Eval #### Syntax ``` {{ eval( "JavaScript code" ) }} ``` Function injects the given JavaScript into the suite code forming the string. #### Examples ``` {{ eval("process.cwd()") }} ``` resolves into ``` `${ process.cwd() }` ``` NPM modules "fs", "path" and "os" as well as Command API () are available for evaluation. Quotation marks in the JavaScript code have to be escaped.