I am writing a function in javascript:
const getContent = async (page, element) => {
const contentStr = await page.evaluate(() => {
const contentEl = document.querySelector(element);
const content = contentEl?.getAttribute("content");
if (content != null && content.length > 0) {
return content;
} else {
return null;
}
});
return contentStr;
};
When executing this function, I am getting an error:
Error: Evaluation failed: ReferenceError: element is not defined
Can anyone help?
This is the function signature of puppeteer's page.evaluate
page.evaluate(pageFunction[, ...args])
As you can see you can pass arguments to the pageFunction as additional paramateters when calling page.evaluate. The reason this is necessary is because one execution context ist node js while the other one is the chromium browser and those contexts run in different processes and don't share memory except when you pass variables via the puppeteer api.
So in your case this might work (not tested):
const getContent = async (page, element) => {
const contentStr = await page.evaluate((element) => {
const contentEl = document.querySelector(element);
const content = contentEl?.getAttribute("content");
if (content != null && content.length > 0) {
return content;
} else {
return null;
}
},element);
return contentStr;
};