CODEWITHSUNDEEP
htmltypescriptdependency-injectionangular-providers
Wira Xie
Wira Xie

Reputation: 839

What Angular Providers do and how to use it?

I'm new with Angular. I follow a tutorial from this link, and i tried to do/add something that doesn't part of that tutorial. I added a providers :[EmployeeService] line to employee-list.component.ts and empployee.component.ts inside @component, and it returns error that said TypeError: Cannot read property 'push' of undefined. So realize that adding providers :[EmployeeService] to some components are unnecessary. I read about Dependency Injection from this link but i do not really get what i wanted to know. So can anyone give me a simple explanation how/when/where to use/put providers and how that error happens?

Thank you very much in advance.

Upvotes: 0

Views: 109

Answers (1)

Martin Nuc
Martin Nuc

Reputation: 5764

providers array tells Angular what services it should instantiate. You can define it on two places:

  1. component
  2. module

When you use providers in component the service will be available to that and all it's children.

When you use it in module the service will be available for all pipes, directives, components and services in given module.

But you can define it in both if you want - in that case Angular will create two instances of the same service.

For beginning provide your services on the module level.

Upvotes: 1

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