angular-cn/tools/api-builder/cheatsheet-package/services/cheatsheetItemParser.js

120 lines
4.0 KiB
JavaScript

/**
* @dgService
* @description
* Parse the text from a cheatsheetItem tag into a cheatsheet item object
* The text must contain a syntax block followed by zero or more bold matchers and finally a description
* The syntax block and bold matchers must be wrapped in backticks and be separated by pipes.
* For example
*
* ```
* `<div [ng-switch]="conditionExpression">
* <template [ng-switch-when]="case1Exp">...</template>
* <template ng-switch-when="case2LiteralString">...</template>
* <template ng-switch-default>...</template>
* </div>`|`[ng-switch]`|`[ng-switch-when]`|`ng-switch-when`|`ng-switch-default`
* Conditionally swaps the contents of the div by selecting one of the embedded templates based on the current value of conditionExpression.
* ```
*
* will be parsed into
*
* ```
* {
* syntax: '<div [ng-switch]="conditionExpression">\n'+
* ' <template [ng-switch-when]="case1Exp">...</template>\n'+
* ' <template ng-switch-when="case2LiteralString">...</template>\n'+
* ' <template ng-switch-default>...</template>\n'+
* '</div>',
* bold: ['[ng-switch]', '[ng-switch-when]', 'ng-switch-when', 'ng-switch-default'],
* description: 'Conditionally swaps the contents of the div by selecting one of the embedded templates based on the current value of conditionExpression.'
* }
* ```
*/
module.exports = function cheatsheetItemParser(targetEnvironments) {
return function(text) {
var fields = getFields(text, ['syntax', 'description']);
var item = {
syntax: '',
bold: [],
description: ''
};
fields.forEach(function(field) {
if (!field.languages || targetEnvironments.someActive(field.languages)) {
switch(field.name) {
case 'syntax':
parseSyntax(field.value.trim());
break;
case 'description':
item.description = field.value.trim();
break;
}
}
});
return item;
function parseSyntax(text) {
var index = 0;
if (text.charAt(index) !== '`') throw new Error('item syntax must start with a backtick');
var start = index + 1;
index = text.indexOf('`', start);
if (index === -1) throw new Error('item syntax must end with a backtick');
item.syntax = text.substring(start, index);
start = index + 1;
// skip to next pipe
while(index < text.length && text.charAt(index) !== '|') index += 1;
while(text.charAt(start) === '|') {
start += 1;
// skip whitespace
while(start < text.length && /\s/.test(text.charAt(start))) start++;
if (text.charAt(start) !== '`') throw new Error('bold matcher must start with a backtick');
start += 1;
index = text.indexOf('`', start);
if (index === -1) throw new Error('bold matcher must end with a backtick');
item.bold.push(text.substring(start, index));
start = index + 1;
}
if (start !== text.length) {
throw new Error('syntax field must only contain a syntax code block and zero or more bold ' +
'matcher code blocks, delimited by pipes.\n' +
'Instead it was "' + text + '"');
}
}
};
}
function getFields(text, fieldNames) {
var FIELD_START = /^([^:(]+)\(?([^)]+)?\)?:$/;
var lines = text.split('\n');
var fields = [];
var field, line;
while(lines.length) {
line = lines.shift();
var match = FIELD_START.exec(line);
if (match && fieldNames.indexOf(match[1]) !== -1) {
// start new field
if (field) {fields.push(field);}
field = { name: match[1], languages: (match[2] && match[2].split(' ')), value: ''};
} else {
if (!field) throw new Error('item must start with one of the following field specifiers:\n' +
fieldNames.map(function(field) { return field + ':'; }).join('\n') + '\n' +
'but instead it contained: "' + text + '"');
field.value += line + '\n';
}
}
if (field) {fields.push(field);}
return fields;
}