Improve the way variables are used while maintaining backward compatibility

[kensoh]

In TagUI, whenever text is expected and user wants to use a variable in place of static text, the current way to do it is using '+variable_name+'. This works because the first ' essentially escapes the text mode to go into JavaScript programming language mode to reference the variable, followed by the second ' to go back to text mode. The + is JavaScript's way of concatenating strings. See below example -

// old way for '+variable+' backward compatibility
locator = 'email_button'
click '+locator+'
number = 5
click (//*[@id="test"])['+variable+']

The old way above works, but is non-standard, hard to write and hard to read. By using backticks ` (the symbol besides the number 1 on keyboard), it can be made easier to type and read. Of course, backticks may have conflict with object repository or datatable definitions. But as long as there isn't such repository / datatable definition, TagUI can interpret the use of `variable` as '+variable+'

// new way of using `variable` to denote variable
locator = 'email_button'
click `locator`
number = 5
click (//*[@id="test"])[`variable`]

This issue is to make this improvement while keeping existing scripts backward compatible.

[kensoh]

Feature usable now in cutting edge version - https://github.com/kelaberetiv/TagUI#set-up

Update of readme & samples after this code enters packaged release, otherwise confusing.

Hey @adegard @Aussiroth @lohvht I thought this is a cool feature and makes variables easier :)

[kensoh]

following additions can semi-work to throw error gracefully if the variable is not yet defined. but it has execution issues for example in 9_misc workflow. even though for loop only until 6, during execution it goes directly to 7 and throws error. dropping exploration of graceful exit in favor of maintaining automation robustness and compatibility of existing scripts.

tagui_parse.php

function parse_variables($script_line) { // `variable` --> '+variable+'
$quote_token = "'+check_variable('"; // token to alternate replacements for '+variable+'
for ($char_counter = 0; $char_counter < strlen($script_line); $char_counter++) {
        if (substr($script_line,$char_counter,1) == "`") {
                $script_line = substr_replace($script_line,$quote_token,$char_counter,1);
                if ($quote_token == "'+check_variable('") $quote_token = "')+'"; else $quote_token = "'+check_variable('";
        }
} return $script_line;}

tagui_header.js

// variable check for graceful exit when `variable` is used and undefined
function check_variable(variable_to_check) {if (check_variable_exit == true) return 'undefined';
try {return eval(variable_to_check);} catch(e) {check_variable_exit = true; // prevent 2X error messages
casper.echo('ERROR - variable ' + variable_to_check + ' is undefined, define it before using').exit();}}

updated - issue happens with eval(),
it messes up order of execution to be non-synchronous and thus not a reliable way to try to exit gracefully using it to processes a variable name provided. pass graceful exit on variable not defined.

[adegard]

Hi @kensoh
I answer now to your question: For me it is not easier because using Italian keyboard backticks ` is not accessible unfortunatly... (so I need to copy paste to use it). But thanks to ask my opinion.

[kensoh]

Hi Arnaud, I see... Ok got it, thanks for your feedback!