Ghost/core/frontend/helpers/match.js
Hannah Wolfe fd20f90cca
Divided f/e proxy into true proxy + rendering service
- The original intention of the proxy was to collect up all the requires in our helpers into one place
- This has since been expanded and used in more places, in more ways
- In hindsight there are now multiple different types of requires in the proxy:
   - One: true frontend rendering framework requires (stuff from deep inside theme-engine)
   - Two: data manipulation/sdk stuff, belongs to the frontend, ways to process API data
   - Three: actual core stuff from Ghost, that we wish wasn't here / needs to be passed in a controlled way
- This commit pulls out One into a new rendering service, so at least that stuff is managed independently
- This draws the lines clearly between what's internal to the frontend and what isn't
- It also highlights that the theme-engine needs to be divided up / refactored so that we don't have these deep requires
2021-09-29 13:10:14 +01:00

110 lines
3.0 KiB
JavaScript

const {labs} = require('../services/proxy');
const {SafeString} = require('../services/rendering');
const logging = require('@tryghost/logging');
const tpl = require('@tryghost/tpl');
const _ = require('lodash');
const messages = {
invalidAttribute: 'Invalid or no attribute given to match helper'
};
/**
* This is identical to the built-in if helper, except inverse/fn calls are replaced with false/true
* https://github.com/handlebars-lang/handlebars.js/blob/19bdace85a8d0bc5ed3a4dec4071cb08c8d003f2/lib/handlebars/helpers/if.js#L9-L20
*/
function isEmptyValue(value) {
if (!value && value !== 0) {
return true;
} else if (Array.isArray(value) && value.length === 0) {
return true;
} else {
return false;
}
}
const handleConditional = (conditional, options) => {
if (_.isFunction(conditional)) {
conditional = conditional.call(this);
}
if (conditional instanceof SafeString) {
conditional = conditional.string;
}
// Default behavior is to render the positive path if the value is truthy and not empty.
// The `includeZero` option may be set to treat the condtional as purely not empty based on the
// behavior of isEmpty. Effectively this determines if 0 is handled by the positive path or negative.
if ((!options.hash.includeZero && !conditional) || isEmptyValue(conditional)) {
return false;
} else {
return true;
}
};
const handleMatch = (data, operator, value) => {
let result;
switch (operator) {
case '!=':
result = data !== value;
break;
default:
result = data === value;
}
return result;
};
function match(...attrs) {
// options = options || {};
// options.hash = options.hash || {};
// options.data = options.data || {};
const options = attrs.pop();
const isBlock = _.has(options, 'fn');
let result;
if (_.isEmpty(attrs)) {
logging.warn(tpl(messages.invalidAttribute));
return;
}
if (attrs.length === 1) {
// If we only have one attribute, treat it as simple true/false (like the if helper)
result = handleConditional(attrs[0], options);
} else if (attrs.length === 3) {
result = handleMatch(attrs[0], attrs[1], attrs[2], options);
} else {
logging.warn(tpl(messages.invalidAttribute));
return;
}
// If we're in block mode, return the outcome from the fn/inverse functions
if (isBlock) {
if (result) {
return options.fn(this);
}
return options.inverse(this);
}
// Else return the result as a string
return new SafeString(result);
}
module.exports = function matchLabsWrapper() {
let self = this;
let args = arguments;
return labs.enabledHelper({
flagKey: 'matchHelper',
flagName: 'Match helper',
helperName: 'match',
helpUrl: 'https://ghost.org/docs/themes/'
}, () => {
return match.apply(self, args);
});
};