MiniProgram TaaS SDK

Prerequisite

• node
• npm
• yarn

If you have not installed yarn, please install it by running npm install -g yarn. This may require root privilege.

Setup

Please ensure that you have already run npm init in the root directory of your MiniProgram project. However, it is suggested that you should install this SDK before you install any other npm modules, otherwise it may cause some side effects if you remove the directory node_modules (See the following steps).

First get the SDK project from here and place it in somewhere. Suppose that the root directory of the SDK project is /path/to/miniprogram-taas-sdk

• Start the shell with the current working directory being the root directory of your MiniProgram project.
• npm install --save /path/to/miniprogram-taas-sdk
• Remove the node_modules directory that is created by the command above.
• yarn install --flat
• Build npm modules in the WeChat DevTools.

Usage Example

​x
const sdk = require("miniprogram-taas-sdk");
​
const ic = "<invitation code>"
// Generate user credential
sdk.getCredential(ic, undefined, (err, data) => {
    if (err) return ;
    const kp = data;
​
    // Store evidence
    const message = {text: "test_message"};
    sdk.storeEvidence(message, undefined, kp, (err, data) => {
        if (err) return ;
        // Get the hash ID
        const hashId = data.hash;
​
        // Query evidence by hash ID
        sdk.queryEvidence(hashId, undefined, kp, (err, data) => {
            if (err) return ;
            // Get the response
            const _message = data.data.text;
            console.log(_message); // Expect: test_message
        });
    });
});
​
​

API documentation

You can import the TaaS SDK in your MiniProgram by:

xxxxxxxxxx
const sdk = require("miniprogram-taas-sdk");

sdk.version

Return the version of TaaS SDK.

The return value is a string which is formatted as "<major version>.<minor version>.<revision>" such as "0.0.1".

sdk.getServerAddr()

Return an address of a TaaS backend server. If there are multiple available servers, return a random one. Different call to this function may return different server addresses, unless there is only one server avaiable.

The return value is a string, which is formatted as "<scheme>://<domain>", such as "http://example.com".

sdk.getCredential(invitationCode, serverAddress, callback)

Generate a pair of credential keys, which contains a public key, a private key, and an API access token.

The invitationCode is the invitation code string.

The serverAddress can be a string that returned by sdk.getServerAddr(), which specify the server address. It also can be undefined (recommended), which means that the server address will be chosen by the SDK itself.

The callback should be a function, which will be called when the server has responded the sdk.storeEvidence request. It will be called as callback(err, obj), and the format of the parameter obj is:

xxxxxxxxxx
{ publicKey: string, privateKey: string, credential: string }

The public key can identify a user.

This function itself does not return any value.

sdk.storeEvidence(data, serverAddress, credential, callback)

Store evidence of the data in the TaaS backend.

The data can be a object, which has the format:

xxxxxxxxxx
{
    path?: string,
    text?: string
}

The data.path is the path to the file which is going to be stored. The data.text is the message to be stored along with the file. You should provide at least a file or a message to be stored. When one in data.path and data.text is provided, the other one can be missing.

The serverAddress can be a string that returned by sdk.getServerAddr(), which specify the server address. It also can be undefined (recommended), which means that the server address will be chosen by the SDK itself.

The credential should be an object that is returned by sdk.getCredential().

The callback should be a function, which will be called when the server has responded the sdk.storeEvidence request. It will be called as callback(err, obj), and the format of the parameter obj is:

xxxxxxxxxx
{
    hash: string,
    sig: string
}

The hash is the hash ID of the stored evidence, and the sig is the signature of the stored evidence.

This function itself does not return any value.

sdk.queryEvidence(hashId, serverAddress, credential, callback)

Query the data according to a hash ID.

The hashId is the hash value to be queried.

The credential should be an object that is returned by sdk.getCredential().

The serverAddress can be a string that returned by sdk.getServerAddr(), which specify the server address. It also can be undefined (recommended), which means that the server address will be chosen by the SDK itself.

The callback should be a function, which will be called when the server has responded the sdk.queryEvidence request. It will be called as callback(err, obj), and the format of the parameter obj is:

xxxxxxxxxx
{
    data: {
        sig: string,
        data: string,
        text?: string,
        type: string
    },
    from: string,
    sig: string,
    timestamp: number
}

The data.data is the saved file data (encoded in base64 format).

The data.type is the type of the stored data. If a message is stored, the data.type will be "text".

The data.text is the text stored along with the data.

The from is the user's public key, which can identify a user.

The timestamp is the timestamp that the user stored the evidence. Technically, it is the number of milliseconds that have elapsed since 1970-01-01 00:00:00 (UTC+8).

This function itself does not return any value.