ngx-dictionary-pipe

Angular 8 pipe for easy dictionary/master data ID to name mapping.

This module is unit-tested. If there is a failing case, please submit an issue so someone can fill a test and fix it.

Badges and other stuff are pending, check TODO list further below.

Installation

Add NgxDictionaryPipeModule to your module imports like this:
``ts
// import it
import { NgxDictionaryPipeModule } from 'ngx-dictionary-pipe';

@NgModule({
declarations: [ ... ],
imports: [
...,
NgxDictionaryPipeModule // add to module
],
})
export class AppModule { }

`

How to use

Define a variable "masterData" with the following data:
`json
{
"books": [
{
"id": 1,
"name": "The dawn of the night"
},
{
"id": 2,
"name": "The dawn of the morning"
}
]
}
`

Define a variable "myBooksIds" with the following data:
`json
[ 1, 3 ]
`

Then, use the dictionary pipe to replace ID occurrences, like this:

`html


• 
  {{ bookId | dictionary : masterData : ['books[]', 'id'] : 'name' }}
  


`

Alternatively, ['books[]', 'id'] can be written as 'books[].id'.

This can be understood as:
`js
const valueToSearch = bookId;
const dictionary = masterData;
const path = ['books[]'];
const valueKey = 'id'; // must equal valueToSearch
const nameKey = 'name'; // resulting readable name
`

This will render the following output:
`html


• 
  The dawn of the night
  


• 
  ???
  


`

Troubleshooting

#### Pipe is printing a blank string
This value is returned if there was an error on the dictionary search. Try setting debug = true when invoking the pipe for displaying debug errors ?, ?? and ???.

> e.g. instead of {{ bookId | dictionary : masterData : ['books[]', 'id'] : 'name' }},
>
> use {{ bookId | dictionary : masterData : ['books[]', 'id'] : 'name' : true }},

If debug is enabled, and it is still printing a blank string, this means the value to search was undefined, null or empty. It's probably the most preferred behaviour.
#### Pipe is printing ?
This means the path was not found, e.g. masterData.bookse in the previous example.
#### Pipe is printing ??
This means the id key was not found, e.g. masterData.books.ide in the previous example.
#### Pipe is printing ???
This means an item with the specified value was not found, e.g. 3 in the previous example.

Is this useful?

Personally speaking, it greatly simplifies many problems I regularly face when I need to replace IDs with names.

If I had to say, it is.

TODO:


- Document abbreviated syntax, e.g. stores.books{} instead of ['stores', 'books'].
- Document [] operator for a loop search, e.g. stores[].books.uuid.
- Document {} operator for a map search, e.g. stores.books{}.
- Document support for value inside [] and {} operators to specify a key to lookup, e.g. stores[1].books{b}.authors and stores[id:1].books{name:b}.authors.
- To consider: Accepting a function instead of nameKey = name for custom browsing, e.g. myFunction(value: any, ...pathItems: any[]) where pathItems is the transversal stack.
- Add "bdictionary" for a binary search based dictionary (performance).
- Add debug flag if required.
- Simplify repository for NPM publish.
- Allow for simple and quick inheritance for enums handling, e.g. {{ statusId | status }}.
- Document support for [] operator at the end of query to collect multiple results instead of returning immediately (filtering).
- In consideration: Add collecting to map support, e.g. books.id{} would make a map { [id]: item }, while books.id{prop}` would group (?).