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102 lines
3.4 KiB
Markdown
102 lines
3.4 KiB
Markdown
---
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description: This page shows how you can get datatokens & download an asset
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---
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# Consume flow
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We assumed that you accomplished the publish flow presented previously.
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Now let's see how can Bob get access to Alice's asset in order to download/consume it.
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### Get access for a dataset 🔑
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Below, we show four possible approaches:
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* A & B are when Alice is in contact with Bob. She can mint directly to him, or mint to herself and transfer to him.
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* C is when Alice wants to share access for free, to anyone
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* D is when Alice wants to sell access
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<figure><img src="../../.gitbook/assets/giphy.webp" alt="" width="199"><figcaption></figcaption></figure>
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In the same Python console:
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```python
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from ocean_lib.ocean.util import to_wei
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#Approach A: Alice mints datatokens to Bob
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datatoken.mint(bob, to_wei(1), {"from": alice})
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#Approach B: Alice mints for herself, and transfers to Bob
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datatoken.mint(alice, to_wei(1), {"from": alice})
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datatoken.transfer(bob, to_wei(1), {"from": alice})
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#Approach C: Alice posts for free, via a dispenser / faucet; Bob requests & gets
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datatoken.create_dispenser({"from": alice})
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datatoken.dispense(to_wei(1), {"from": bob})
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#Approach D: Alice posts for sale; Bob buys
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# D.1 Alice creates exchange
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price = to_wei(100)
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exchange = datatoken.create_exchange({"from": alice}, price, ocean.OCEAN_address)
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# D.2 Alice makes 100 datatokens available on the exchange
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datatoken.mint(alice, to_wei(100), {"from": alice})
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datatoken.approve(exchange.address, to_wei(100), {"from": alice})
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# D.3 Bob lets exchange pull the OCEAN needed
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OCEAN_needed = exchange.BT_needed(to_wei(1), consume_market_fee=0)
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ocean.OCEAN_token.approve(exchange.address, OCEAN_needed, {"from":bob})
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# D.4 Bob buys datatoken
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exchange.buy_DT(to_wei(1), consume_market_fee=0, tx_dict={"from": bob})
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```
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For more info, check [Technical Details](https://app.gitbook.com/o/mTcjMqA4ylf55anucjH8/s/BTXXhmDGzR0Xgj13fyfM/\~/changes/336/developers/ocean.py/technical-details) about ocean.py most used functions and also the smart contracts for [Dispenser](https://github.com/oceanprotocol/contracts/blob/main/contracts/pools/dispenser/Dispenser.sol) & [Fixed Rate Exchange](https://github.com/oceanprotocol/contracts/blob/main/contracts/pools/fixedRate/FixedRateExchange.sol).
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### Consume the asset ⬇️
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To "consume" an asset typically means placing an "order", where you pass in 1.0 datatokens and get back a url. Then, you typically download the asset from the url.
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Bob now has the datatoken for the dataset! Time to download the dataset and use it.
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<figure><img src="../../.gitbook/assets/200w.webp" alt=""><figcaption></figcaption></figure>
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In the same Python console:
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```python
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# Bob sends a datatoken to the service to get access
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order_tx_id = ocean.assets.pay_for_access_service(ddo, {"from": bob})
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# Bob downloads the file. If the connection breaks, Bob can try again
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asset_dir = ocean.assets.download_asset(ddo, bob, './', order_tx_id)
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import os
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file_name = os.path.join(asset_dir, "file0")
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```
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Let's check that the file is downloaded. In a new console:
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```bash
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cd my_project/datafile.did:op:*
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cat file0
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```
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The _beginning_ of the file should contain the following contents:
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```bash
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% 1. Title: Branin Function
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% 3. Number of instances: 225
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% 6. Number of attributes: 2
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@relation branin
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@attribute 'x0' numeric
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@attribute 'x1' numeric
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@attribute 'y' numeric
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@data
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-5.0000,0.0000,308.1291
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-3.9286,0.0000,206.1783
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...
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```
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