Filters object not working for web3.eth.contract getPastEvents() method

Question

I have referred, Web3 Events, but filters object is not working for me, I've got the same result for events before and after applying filter object.

Here's the code:

 instance.getPastEvents(
    "Transfer",
    {filter: {value: [117,50]}},
    { fromBlock: 0 , toBlock: "latest" },
    (errors, events) => {
         if (!errors) {
            console.log(events);
         }
     }
);

What does that filter object really means, According to documentations and references it is custom fields but it must be object parameters.

Suggestion needed to correct the filters use.

Answer 1

Filters only work if the parameter is indexed. For example, the ERC20.Tranfer event is defined as Transfer(address indexed from, address indexed to, uint tokens), so only from and to can be used in filters.

Edit: I just noticed, you're submitting the filter as a separate object. The correct format is this:

 instance.getPastEvents(
    "Transfer",
    {
      filter: {value: [117,50]},
      fromBlock: 0 ,
      toBlock: "latest"
    }, (errors, events) => {
         if (!errors) {
            console.log(events);
         }
     }
);

Answer 2

Using web3 1.2.2, I observed that if you use a precise identifier e.g. transactionHash then will not work when combined with fromBlock and toBlock.

Precise result returned:

filter: {
    transactionHash: txObj.transactionHash,
},

All results:

{
    filter: {
        transactionHash: txObj.transactionHash,
    },
    fromBlock: 0,
    toBlock: 'latest'
}