最近我正在开发一个带有此扩展的项目，我注意到当我选择＆＃34; FIELD＆＃34;选项并输入一切正常。但是在我从字段中删除值并推送因为未定义的值而进入整个应用程序崩溃。也许有人可以帮我代码如何避免这种烦人的崩溃？
提前谢谢！这是完整的代码。
/*global define*/
define(["qlik"], function(qlik) {
'use strict';
var BTN_SELECTED = 'qui-button-selected',
BTN = 'qui-button',
SELECT = 'qui-select',
INPUT = 'qui-input';
function createVariable(name) {
var app = qlik.currApp();
//from 2.1: check if variable exists
if (app.variable.getByName) {
app.variable.getByName(name).then(function() {
//variable already exist
}, function() {
//create variable
app.variable.create(name);
});
} else {
//create variable - ignore errors
app.variable.create(name);
}
}
function createElement(tag, cls, html) {
var el = document.createElement(tag);
if (cls) {
el.className = cls;
}
if (html !== undefined) {
el.innerHTML = html;
}
return el;
}
return {
initialProperties: {
variableValue: {},
variableName: "",
render: "f",
defaultValue: 0,
alternatives: []
},
definition: {
type: "items",
component: "accordion",
items: {
settings: {
uses: "settings",
items: {
variable: {
type: "items",
label: "Variable",
items: {
name: {
ref: "variableName",
label: "Name",
type: "string",
change: function(data) {
createVariable(data.variableName);
data.variableValue.qStringExpression = '=' + data.variableName;
}
},
render: {
type: "string",
component: "dropdown",
label: "Render as",
ref: "render",
options: [{
value: "b",
label: "Button"
}, {
value: "s",
label: "Select"
}, {
value: "f",
label: "Field"
}, {
value: "l",
label: "Slider"
}],
defaultValue: "f"
},
emptyVal: {
ref: "emptyVal",
label: "default(when empty)",
type: "string",
defaultValue: 0
},
alternatives: {
type: "array",
ref: "alternatives",
label: "Alternatives",
itemTitleRef: "label",
allowAdd: true,
allowRemove: true,
addTranslation: "Add Alternative",
items: {
value: {
type: "string",
ref: "value",
label: "Value"
},
label: {
type: "string",
ref: "label",
label: "Label",
expression: "optional"
}
},
show: function(data) {
return data.render === "b" || data.render === "s";
}
},
min: {
ref: "min",
label: "Min",
type: "number",
defaultValue: 0,
show: function(data) {
return data.render === "l";
}
},
max: {
ref: "max",
label: "Max",
type: "number",
defaultValue: 100,
show: function(data) {
return data.render === "l";
}
},
step: {
ref: "step",
label: "Step",
type: "number",
defaultValue: 1,
show: function(data) {
return data.render === "l";
}
}
}
}
}
}
}
},
paint: function($element, layout) {
var wrapper = createElement('div'),
ext = this;
empty = layout.emptyVal;
if (layout.render === 'b') {
layout.alternatives.forEach(function(alt) {
var clazz = alt.value === layout.variableValue ? BTN_SELECTED : BTN;
var btn = createElement('button', clazz, alt.label);
btn.onclick = function() {
qlik.currApp(ext).variable.setContent(layout.variableName, alt.value);
}
wrapper.appendChild(btn);
});
} else if (layout.render === 's') {
var sel = createElement('select', SELECT);
layout.alternatives.forEach(function(alt) {
var opt = createElement('option', undefined, alt.label);
opt.value = alt.value;
opt.selected = alt.value === layout.variableValue;
sel.appendChild(opt);
});
sel.onchange = function() {
qlik.currApp(ext).variable.setContent(layout.variableName, this.value);
}
wrapper.appendChild(sel);
} else if (layout.render === 'l') {
var range = createElement('input');
range.type = 'range';
range.min = layout.min || 0;
range.max = layout.max || 100;
range.step = layout.step || 1;
range.value = layout.variableValue;
range.title = layout.variableValue;
range.style.width = '98%';
range.onchange = function() {
qlik.currApp(ext).variable.setContent(layout.variableName, this.value);
}
wrapper.appendChild(range);
} else {
var fld = createElement('input', INPUT);
fld.type = 'number';
fld.value = layout.variableValue;
fld.onchange = function () {
if (this.value != "undifined") {
qlik.currApp(ext).variable.setContent(layout.variableName, this.value);
} else {
qlik.currApp(ext).variable.setContent(layout.variableName, 0);
}
}
wrapper.appendChild(fld);
}
var elem = $element[0];
if (elem.childNodes.length === 0) {
elem.appendChild(wrapper);
} else {
elem.replaceChild(wrapper, elem.childNodes[0]);
}
}
};
});
答案 0 :(得分：0)
if (this.value != "undifined") {
在这里，您要将value与字符串 "undifined"进行比较（也是错误的）。
您似乎想要与值 undefined进行比较：
if (this.value !== undefined) {
或检查value的数据类型：
if (typeof this.value != "undefined") {