我只想在 firebase 中显示具有匹配字段的文档

Question

As in the title, I want to show only documents with matching fields in Firebase.

Now my code using jquery looks like this:

 const db = firebase.firestore(); db.collection('product').get().then((product)=>{ product.forEach((doc)=>{ var li = ""; console.log(doc.data()) if(topic == doc.data().topic){ li = ` <div> <img class="${img}" src="${doc.data().img}"> <p class="text-500 text-white">${doc.data().title}</p> </div> ` }else{ li = ` <div> <img class="${img}" src="${doc.data().img}"> <p class="text-500 text-white">${doc.data().title}</p> </div> ` } $(`.app`).append(li) }) });

 <div class="app"></div>

All documents are now available. For example, if the current URL is "https://example.com?topic=firebase", I want to display only the contents of the documents with the topic field firebase in the documents in a collection called product.

Thank you in advance.

Answer 1

To get the value of the URL parameter "topic", try this:

function getParameterByName(name, url) {
    if (!url) url = window.location.href;
    name = name.replace(/[\[\]]/g, '\\$&');
    var regex = new RegExp('[?&]' + name + '(=([^&#]*)|&|#|$)'),
        results = regex.exec(url);
    if (!results) return null;
    if (!results[2]) return '';
    return decodeURIComponent(results[2].replace(/\+/g, ' '));
}

const topic = getParameterByName("topic", window.location.href);