Can't send image with Slackbot using slackbots (javascript) - node.js

Question

I'm using slackbots (https://github.com/mishk0/slack-bot-api) to create an interactive bot.
I can, as a user, send message in chat and having my bot giving me an answer depending on what i wrote. Like if I type : !weekend, my bot will answer if weekend is close or not by fetching an API.
It's working this way
bot.on('message', data => {
if (data.type !== 'message') {
return;
}
handleMessage(data.text);
});
function handleMessage(message) {
switch (message) {
case '!weekend':
case '!we':
fetchWeekendData();
break;
case '!apero':
case '!biere':
case '!pastis':
fetchAperoData();
break;
case '!meteo':
fetchWeatherData();
break;
case '!metro':
fetchMetroData('A');
fetchMetroData('R');
break;
case '!features':
getFeatures();
break;
}
}
function fetchWeekendData() {
axios.get('https://estcequecestbientotleweekend.fr/api',
).then(res => {
const weText = res.data.text;
postToChannel(`_Bientôt le week end ?_ : *${weText}*`);
});
}
function postToChannel(message) {
bot.postMessageToChannel(
'général',
message,
params
)
}
I have another function calling, this time, a weather api. The api respond with many infos and
a link to a png depending on the weather. A little weather icon.
Problem is, when i send back my message to chat, it send the image link and i just can't figure out how to get this link as an image in chat.
function fetchWeatherData() {
axios.get('http://api.weatherstack.com/current?access_key=myAPIkey&query=Paris&units=m',
).then(res => {
const location = res.data.location.name;
const icon = res.data.current.weather_icons;
const temperature = res.data.current.temperature;
const feelslike = res.data.current.feelslike;
const humidity = res.data.current.humidity;
postToChannel(`Météo à *${location}* : ${icon} \n>_Température_ : *${temperature}* °C _Ressenti_ : *${feelslike}* °C\n\n>_Humidité_ : *${humidity}* %`)
});
}
If anyone has already used slack-bot-api and posted images with his bot, I'd like to know how you did this cause I'm running out of idea, slack api docs is showing JSON attachments for images but I don't know how to use it with this package.
EDIT : Alright it's solved, this way
function postToChannelWithImage() {
bot.postMessageToChannel(
'général',
'yikes itis working',
params = {
"icon_url": "https://avatars.slack-edge.com/2020-02-04/935676215584_38623245747b942874b5_192.jpg",
"attachments":
[
{
"fallback": "this did not work",
"image_url": "https://a.slack-edge.com/80588/img/blocks/bkb_template_images/beagle.png"
}
]
}
)
}
I added the array and it worked perfectly, I just have to add other params into the same array to keep my config the way it is.
Thanks a lot to #Erik Kalkoken !!

Answer 1

This library seams to just forward parameters to the respective Slack API method, which is chat.postMessage.
To post an image with Slack you need to include an image URL either within an attachment (outmoded) or blocks.
e.g. to attach an image wit attachments you would add this array via params:
{
"attachments":
[
{
"fallback": "this did not work",
"image_url": "https://a.slack-edge.com/80588/img/blocks/bkb_template_images/beagle.png"
}
]
}