jsonPlaceholderReplacer
Lightweight yet really powerful typescript library/cli to replace placeholders in an javascript object/JSON. By default, all you have to do is to use double curly brackets {{placeholderKey}} or angle brackets <<placeholderKey>>, interchangeably, to identify the placeholder. Don't worry, if you don't like these default placeholders you can create your own.
CLI usage
json-placeholder-replacer annotetad-json.json [...variableMaps]Example
$ json-placeholder-replacer annotated.json variable_map.json $ jpr variable_map.json < annotated.json $ cat annotated.json | jpr variable_map.json $ echo '{"curly": "{{key}}", "angle": "<>"}' | jpr variable_maps
Would result
cat replaceable.json
# {
# "curly": "{{key}}",
# "angle": "<<key>>"
# }
cat variable.map:
# {
# "key": 10,
# "not-mapped": 20
# }
json-placeholder-replacer replaceable.json variable.map
# {
# "curly": 10,
# "angle": 10,
# "not-mapped": 20
# }Library usage
import { JsonPlaceholderReplacer } from "json-placeholder-replacer";
const placeHolderReplacer = new JsonPlaceholderReplacer();
placeHolderReplacer.addVariableMap({
key: 100,
otherKey: 200,
});
const afterReplace = placeHolderReplacer.replace({
replaceable: "{{key}}",
otherReplaceableWithSameKey: "<<key>>",
otherReplaceable: "{{otherKey}}",
});
// afterReplace = {
// replaceable: 100,
// otherReplaceableWithSameKey: 100,
// otherReplaceable: 200
// }You can replace the default placeholders with some as cool as you want
const placeHolderReplacer = new JsonPlaceholderReplacer({
delimiterTags: [{ begin: "@{{-", end: "-}}@" }],
});
placeHolderReplacer.addVariableMap({
key: "nice",
});
const afterReplace = placeHolderReplacer.replace({
replaceable: "@{{-key-}}@",
});
// afterReplace = {
// replaceable: "nice",
// }It's also possible to add more than one variables map
placeHolderReplacer.addVariableMap({
firstMapKey: "1",
});
placeHolderReplacer.addVariableMap({
secondMapKey: 2,
});
const afterReplace = placeHolderReplacer.replace({
replaceable: "{{firstMapKey}}",
otherReplaceable: "<<secondMapKey>>",
});
// afterReplace = {
// replaceable: "1",
// otherReplaceable: 2
// }And the last added maps have higher priority, so
placeHolderReplacer.addVariableMap({
id: "lowerPriority",
});
placeHolderReplacer.addVariableMap({
id: "higherPriority",
});
const afterReplace = placeHolderReplacer.replace({
replaceable: "{{id}}",
});
// afterReplace = {
// replaceable: "higherPriority"
// }It keeps original variable types
If a variable in the map is boolean/string/number/object, it remains as boolean/string/number/object when it's replaced
placeHolderReplacer.addVariableMap({
booleanKey: true,
stringKey: "string",
numberKey: 10,
objectKey: {
inner: "inner",
},
});
const afterReplace = placeHolderReplacer.replace({
booleanReplaceable: "{{booleanKey}}",
stringReplaceable: "{{stringKey}}",
numberReplaceable: "{{numberKey}}",
objectReplaceable: "{{objectKey}}",
});
// afterReplace = {
// booleanReplaceable: true,
// stringReplaceable: "string",
// numberReplaceable: 10,
// objectReplaceable: {
// inner: "inner"
// }
// }Just to make it clearer, it does not replace the placeholder Key
placeHolderReplacer.addVariableMap({
key: "someValue",
});
const afterReplace = placeHolderReplacer.replace({
"{{key}}": "value",
});
// afterReplace = {
// "{{key}}": "value"
// }And, of course, it handles array substitution as well
placeHolderReplacer.addVariableMap({
key: 987,
objectReplaceable: {
inner: "inner"
}
});
const afterReplace = placeHolderReplacer.replace({
array: ["string", "{{objectReplaceable}}", {{key}}]
})
// afterReplace = {
// array: ["string", {
// inner: "inner"
// }, 987]
// }Want to get nested elements? Go for it
placeHolderReplacer.addVariableMap({
key: {
nested: "value",
},
});
const afterReplace: any = placeHolderReplacer.replace({
replaceable: "<<key.nested>>",
});
// afterReplace = {
// replaceable: "value"
// }This feature allows you to have default values in case you don't have them mapped
placeHolderReplacer.addVariableMap({
key: "value",
});
const afterReplace: any = placeHolderReplacer.replace({
replaceable: "<<not-found-key:default-value>>",
});
// afterReplace = {
// replaceable: "default-value"
// }Of course, you can also change what is the default value separator (defaults to ':')
const placeHolderReplacer = new JsonPlaceholderReplacer({
defaultValueSeparator: ":=:",
});
placeHolderReplacer.addVariableMap({
key: "value",
});
const afterReplace: any = placeHolderReplacer.replace({
replaceable: "<<not-found-key:=:default-value>>", // Note the ':=:'
});
// afterReplace = {
// replaceable: "default-value"
// }